Class 
 
 Book 
 
 L-IBRKRV 
 
 OF THE 
 
 MEDICAL DEPARTMENT, 
 
 TULANE UNIVERSITY OF LOUISIANA 
 
 PRESENTED BY 
 
 / 
 
THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 PRESENTED BY 
 
 PROF. CHARLES A. KOFOID AND 
 MRS. PRUDENCE W. KOFOID 
 
ELEMENTS 
 
 GENERAL ANATOMY, 
 
 - 
 
 OR, 
 
 A DESCRIPTION OF EVERY KIND OF ORGANS COMPOSING THE 
 HUMAN BODY. 
 
 P. A. BECLARD, 
 
 PROFESSOR OF ANATOMY OF THE FACULTY OF MEDICINE OF PARIS. 
 
 
 
 Preceded by a Critical and Biographical Memoir of the Life and Writings of 
 
 the Author, 
 
 BY OLIVIER, M. D. 
 TRANSLATED FROM THE FRENCH, WITH NOTES, 
 
 BY JOSEPH TOGNO, M. B. 
 
 MEMBER OF THE PHILADELPHIA MEDICAL SOCIETY. 
 
 CAREY AND LEA. 
 
 1830. 
 
 
 / 
 
I 
 
 Eastern District of Pennsylvania, to wit: 
 
 BE IT REMEMBERED, that on the twentieth day of October, in the 
 fifty -fifth year of the Independence of the United States of America, A.D. 
 1830, Carey & Lea of the said district have deposited in this office the 
 title of a book, the right whereof they claim as proprietors in the words 
 following, to wit: 
 
 *' Elements of General Anatomy, or, a description of every kind of organs 
 composing the human body. By P. A. Beclard, Professor of Anatomy of 
 the Faculty of Medicine of Paris. Preceded by a critical and Biographical 
 Memoir of the Life and Writings of the Author, by Olivier, M. D. Trans- 
 lated from the French, with notes, by Joseph Togno, M. D. Member of 
 the Philadelphia Medical Society." 
 
 P 
 
 In conformity to the Act of the Congress of the United States, entitled 
 "An Act for the encouragement of learning, by securing the copies of 
 maps, charts, and books to the authors and proprietors of such copies 
 during the times therein mentioned;" And also to the Act entitled " An 
 Act supplementary to an Act entitled An Act for the encouragement of 
 learning by securing the copies of maps, charts, and books to the authors 
 and proprietors of such copies during the times therein mentioned,' and ex- 
 tending the benefits thereof to the arts of designing, engraving, and etching 
 historical and other prints." 
 
 D. CALDWELL, 
 Clerk of the Eastern District of Pennsylvania. 
 
 f 
 
 
< 
 
 
 
 THE MEMORY 
 
 BICHAT, BECL.ARD, 
 
 THE TRANSLATOR. 
 
 

THE TRANSLATOR'S PREFACE. 
 
 The task of the translator, although very confined, is not 
 altogether unimportant to the advancement of the arts and 
 sciences, and especially to the improvement of the medical 
 science in this country, at this present time. 
 
 Forbidden to add to, or to subtract from the original, the 
 translator's business is simply to interpret and translate his 
 author's meaning faithfully, and to render it in clear and in- 
 telligible language. 
 
 It has been the fate of the translator of the present work, to 
 give an English version of the last labours of the lamented 
 Bichat; and now, again, the ten-fold more difficult, but pleas- 
 ing task devolves on him, of presenting to the medical profes- 
 sion of this country, the last work of the eminent, erudite, and 
 much lamented Beclard. 
 
 The object of the translator will be fulfilled, and he will be 
 repaid for his trouble, if without deviating from his author, 
 he has made the original, clear and comprehensible to his 
 English reader. But should some stern critic, eager to find 
 fault, censure the performance, which has cost the trans- 
 lator much labour, trouble and solicitude ; and under circum- 
 stances that the reader is seldom solicitous to know, and sel- 
 domer inclined to make due allowance for ; let him remember, 
 that if this English version is not faultless, still much has been 
 
VI 
 
 done to render it worthy of the approbation of the profession. 
 Indeed, I may well be contented, without claiming for this 
 translation, the praise of perfection, while I daily witness 
 similar attempts, coming from higher sources, not altogether 
 exempt from errors. 
 
 For instance, since the greater part of this version has been 
 printed, we have had in our hands the translation of the same 
 work by Dr. Knox of Edinburg, well known to the medical 
 profession as a writer and a lecturer. We opened this volume 
 by chance in many places, and we have, not without great sur- 
 prise, found some very gross errors. We will point out some 
 of them, not to gratify malice or jealousy on our part, but 
 merely to show that the faithful and correct performance of a 
 translation, is not as easy a task as some critics would make us 
 believe. Should we ourselves have fallen into errors, not- 
 withstanding all our care and attention to produce a faultless 
 translation, we wish thereby to show, that we are entitled to 
 some indulgence from our reader. 
 
 Dr. Knox points out one single error in his erratum, and 
 we turned to the page indicated ; on reading the same para- 
 graph, we found just above the error alluded to the following 
 sentence, which we shall give with the original, and opposite to 
 our own version. This induced us to look cursorily into the 
 book, and to our great astonishment, we found such errors, in 
 point of science, as made us rather tremble for the performance 
 of the other parts of the work. We shall here quote some of 
 the principal blunders committed by Dr. Knox, for the edifica- 
 tion of our readers. 
 
 
THE TRANSLATOR'S PREFACE. 
 
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 THE TRANSLATOR'S PREFACE. 
 
THE TRANSLATOR'S PREFACE. 
 
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We ought to say a few words in commendation of the ori- 
 ginal work of Beclard; but we believe its merits so well 
 known that we shall dispense ourselves from dwelling on them. 
 However, we know that there exists yet, among some of the 
 younger members of the profession, a very false and errone- 
 ous idea of what GENERAL ANATOMY really means. In order 
 to elucidate this subject, we shall extract the following excel- 
 lent explanatory passage from a Lecture of Dr. Godman on 
 General Anatomy. 
 
 " We have in the outset to regret that the use of a term should 
 have led to misapprehension among some of the members of 
 our profession, who from the title General Anatomy, have re- 
 ceived an impression that it is nothing more than a general 
 outline, or sketch of common or special anatomy, stripped of 
 its minuteness. 
 
 " Such an idea of General Anatomy is totally erroneous, and 
 has in some instances led to the most injurious neglect of pre- 
 cious knowledge. General anatomy is the science of organi- 
 zation, not of individual organs. It teaches the elementary 
 textures composing all the parts of the body without reference to 
 the specific structures they aid in forming. In this sense alone, 
 it is general, but in the determination of the qualities and laws 
 of the elementary textures, and of the manner in which these 
 are linked together, this science is most minute, precise, and 
 definite, bringing us into the most intimate acquaintance with 
 the entire economy of the system, and breaking down the bar- 
 riers which the habit of exclusively studying special organs, 
 invariably raises around us. 
 
 " General Anatomy, then, is not descriptive or Special Ana- 
 tomy in outline, but the anatomy of elementary textures, of 
 
THE TRANSLATOR'S PREFACE. xi 
 
 minute organization without reference to form or place. It 
 is to Anatomical science what Chemistry is to the other branch- 
 es of natural science. Whatever may be the texture examined, 
 it is considered in all aspects, and throughout every modifica- 
 tion, whether it be found in the substance of tendon, muscle, 
 ligament or bone. All its qualities are sought, the distinctive 
 characters established, and the laws of its susceptibilities and 
 actions deduced from the amplest experiments and observa- 
 tions.'' 
 
 October, 1830. 
 

CONTENTS. 
 
 PAGE. 
 
 Translator's Preface v 
 
 Preface xii 
 
 Memoir on the life and writings of Beclard 1 
 
 Introduction 19 
 
 SECTION I. Of organized bodies ib. 
 
 Of animals 26 
 
 Of vertebrate animals 58 
 
 Of the viviparous vertebrate animals - 70 
 
 IL Of the human body 74 
 
 Of the fluids 79 
 
 Of the organs 84 
 
 Ofthe organism - 94 
 
 Of the development and differences of the organization 98 
 
 Of the alterations of the organization - 104 
 
 Of death and the cadaver ..... 106 
 
 CHAPTER I. 
 
 Of the cellular and adipose tissues 113 
 
 SECTION I. Of the cellular tissue ib. 
 
 II. Ofthe adipose tissue ... ... 128 
 
 ART. I. Of the common adipose tissue ... 129 
 
 II. Of the medullary, or adipose tissue of the bones 140 
 
 CHAPTER II. 
 
 Of the serous membranes - - - - - - -147 
 
 SECTION. I. Ofthe serous membranes in general 148 
 
 II. ART. I. Of the sub-cutaneous synovial bursx - - 160 
 
 II. Of the synovial membranes of the tendons - 162 
 
 III. Of the articular synovial capsules - - 166 
 
 IV. Of the serous splanchnic membranes - - 173 
 
XIV CONTENTS. 
 
 PAQI. 
 CHAPTER III. 
 
 Of the tegumentary membranes 181 
 
 SECTION I. Of the tegumentary membranes generally - 182 
 
 II. Of the mucous membrane 191 
 
 ffl. Of the skin 204 
 
 ABT. I. Of the skin in general 205 
 
 H. Of the appendages of the skin ... 226 
 
 I. Of the nails ib, 
 
 H. Of the hairs 230 
 
 CHAPTER IV. 
 
 Of the vascular system 237 
 
 SECTION I. ART. I. Of the the vessels generally ... 239 
 
 II. Of the termination of the vessels - - - 251 
 
 I. Of the capillary vessels .... 252 
 
 II. Of the erectile tissue 269 
 
 III. Of the vascular ganglia .... 273 
 
 H. Of the arteries - ..... 275 
 
 HI. Of the veins 293 
 
 IV. Of the lymphatic system 305 
 
 ART. I. Of the lymphatic vessels .... jj. 
 
 II. Of the lymphatic ganglia - 311 
 
 CHAPTER V. 
 
 Of the glands - 315 
 
 CHAPTER VI. 
 
 Of the ligamentous tissue 323 
 
 SECTION I. Of the ligamentous tissue generally - 324 
 
 II. Of the ligamentous organs in particular - - - 330 
 
 ART. I. Of the ligaments ib. 
 
 n. Of the tendons - 332 
 
 HI. Of the ligamentous envelopes - - - 334 
 
 A. Of the envelopes of the muscles - - ib. 
 
 B. Of the sheaths of the tendons 336 
 
 C. Of the periosteum ib. 
 
 D . Of the fibrous envelopes of the nervous system 338 
 
 E. Of the compound fibrous membranes - - ib. 
 
 F. Of the fibrous capsules of some organs > 339 
 in. Of the fibro-cartilaginous tissue ib. 
 
 CHAPTER VII. 
 
 Of the cartilages - - 344 
 

 
 
 CONTENTS. XV 
 
 PAGE. 
 
 SECTION I. Of the cartilages in general 345 
 
 II. Of the different kinds of cartilages - - - 349 
 
 ART. I. Of the articular cartilages .... i b. 
 
 II. Of the costal, laryngeal and other cartilages - 352 
 
 III. Of the membraniform cartilages - 355 
 
 CHAPTER VIII. 
 
 Of the osseous system - - - 356 
 
 SECTION I. Of the bones 358 
 
 II. Of the articulations - 395 
 
 III. Of the skeleton- - 405 
 
 CHAPTER IX. 
 
 Of the muscular system 409 
 
 SECTION I. Of the muscular system generally 411 
 
 II. Of the interior muscles 437 
 
 III. of the exterior muscles 441 
 
 CHAPTER X. 
 
 Of the nervous system 457 
 
 SECTION I. Of the nervous system generally 464 
 
 H. Of the nerves in general 485 
 
 III. Of the ganglions and sympathetic nerve - - - 502 
 
 CHAPTER XL 
 
 Of accidental productions 519 
 
 SECTION I. Of accidental humours ib. 
 
 II. Of stony concretions 523 
 
 III. Of accidental tissues 525 
 
 ART. I. Of analogous accidental tissues 527 
 
 II. Of heterologous accidental tissues ib. 
 
 I. Of tubercles - - - 528 
 
 II. Of the encephaloid tumour 529 
 
 III. Ofschirrus - 531 
 
 IV. Ofmelanosis - 532 
 V. Of cirrhosis, &c. 533 
 
 VI. Of compound morbid tissues ... 534 
 
 IV. Of foreign animated bodies 535 
 ART. I. Of intestinal worms - ib. 
 
 I. Of vesicular worms ----- 536 
 
 II. Of the flat worms - 537 
 
 III. Of cylindrical worms .... 538 
 II. Of parasitic animals 540 
 

 
 
PREFACE. 
 
 The work I publish is a compendium of a course of anatomy, 
 which I have been delivering for these ten years past ; and 
 is solely intended for students of medicine. My object in 
 publishing it, is to offer them, in a small volume, an abridg- 
 ment of the numberless labours undertaken for more than 
 twenty centuries, in the science of the organization of man. 
 
 I divide the anatomy of man into general anatomy, special 
 anatomy of the organs, and anatomy of the regions. This 
 volume contains only the General Anatomy, and may be con- 
 sidered either as a separate work, or as the first part of a ge- 
 neral treatise. 
 
 In writing this part of Anatomy, I have made a liberal use 
 of the work of our celebrated Bichat, as well as of those works 
 which have since been published on the same subject. I have 
 also consulted treatises ex-professo, for each system or kind 
 of organs. I have been careful to quote in every chap- 
 ter, the titles of the works which furnished me with the ma- 
 terials necessary to compose it, less with the view of making 
 an easy and vain display of erudition, than to exempt others 
 from the necessity of reading the works which 1 was myself 
 obliged to peruse; and at the same time to point out, to those 
 who are anxious to make farther researches and more profound 
 studies, a sort of select anatomical library. I have also indi- 
 cated the plates, which may be consulted with advantage for 
 each kind of organ. 
 2 
 
VI PREFACE. 
 
 1 have begun each chapter, with an abridged history of 
 the principal discoveries made respecting the system of organs 
 which comj&ose it; to enable me, the better to compile some 
 of these historical notices, I made free use of Lauth's History 
 of Anatomy, of which as yet one volume only is published. 
 
 The introduction treats, in the first section, of organization 
 in general, and in the second, of the human body. It was my 
 intention, in the first section, to give merely to my reader a 
 general idea of comparative anatomy and physiology. In so 
 doing, it was not my object to exempt the student from 
 studying the anatomy of animals; but on the contrary, to 
 show them the utility of this kind of knowledge. In writing 
 this part of the introduction, I have profited by the labours of 
 Dumeril, Blainville, Geoffroy Saint Hilaire, Lamarck, and 
 especially of those of Cuvier, whom I could have cited at 
 every page. In the second part of the introduction, I have 
 given general views of the human body ; I have spoken of its 
 humours generally, part of the science of organization too 
 much neglected, since Haller and his school, who erroneously 
 thought they had found the whole secret of life in the nervous 
 system, and in the phenomena of irritability and sensibility. 
 
 Anatomy not being an object of mere speculation and sterile 
 curiosity to the physician, but the basis of all knowledge re- 
 lating to medicine, I thought that physiology and pathology, 
 ought not to be entirely separated from it. Pathological 
 anatomy, particularly, ought, in my estimation, to be connected 
 with special anatomy, and in this view, the description of each 
 tissue is terminated, by a brief survey of the varieties and 
 alterations therein observed, and the whole work itself is con- 
 cluded by a chapter on anomalous or accidental productions, 
 common to all, or to several kinds of organs. 
 
 P. A. BECLARD. 
 
 Paris, August 30th, 1223. 
 
ON THE 
 
 LIFE AND WRITINGS 
 
 OF 
 
 BECLARD. 
 
 To write the life of a celebrated man, is at once to honour 
 his memory, and confer a benefit on society; for, while we 
 recall to mind the triumphs of him whose every step was 
 crowned with success, we teach those who wish to imitate him, 
 by what means glory is attained, and of what value, in this 
 world, is a reputation justly acquired. It is with this double 
 object in view, that we propose to lay before our readers, the 
 laborious life of the learned man, whom the school of medicine 
 of Paris will long regret, and of which he was one of the no- 
 blest ornaments. 
 
 Peter Augustine Beclard was born at Angers, October 12th, 
 1785. His parents had no other fortune than their good name, 
 and in their family probity was hereditary. His father, al- 
 though loaded with the cares of a numerous family, by a strict 
 economy, was enabled to give to each of his children the ele- 
 mentary education, requisite to enable them to continue the 
 limited business which supported them. Thus, when young 
 Beclard had learned to read, write and cipher, he was made to 
 understand that to this, the extent of his knowledge should be 
 confined. But either because he had a foreboding of his future 
 success, or that he was inspired by instinct, or by an irresisti- 
 ble inclination, Beclard, heedless of these remarks, eagerly 
 read every book which fell into his hands. 
 
2 LIFE AND WRITINGS OP BECLARD. 
 
 The central schools, which had been established in the de- 
 partments, and from the heart of which radiated the instruc- 
 tion destined to enlighten a regenerated nation, were then in 
 all their activity. Beclard had himself inscribed as one of the 
 pupils of that formed at Angers, and he was soon remarked 
 for his proficiency and rapid improvement. Here, for the first 
 time, he discovered the advantages of study; here he was im- 
 bued with the love of the sciences, and here he learned to 
 worship them. Notwithstanding the illusions with which he 
 already fed his ardent soul, his relations saw with sorrow such 
 dispositions developed in him, and in order to keep him in 
 the rank in which he was born, they from time to time, tried 
 to make of him a clerk of a store, then of a lottery office, and 
 at last secretary to the director of the stage-office. Beclard 
 but ill fulfilled those employments for which he had great re- 
 pugnance, and but little aptitude; and indeed, he was consi- 
 dered by his employers as unfit for the occupations of busi- 
 ness. The disgust that he experienced in this situation, very 
 unsuitable to his natural inclinations, from this moment tinged 
 with melancholy the character of Beclard, which afterwards 
 redounded to his advantage, by early preparing his mind for 
 that kind of meditation which the profound cultivation of 
 science always demands. 
 
 There is an epoch in the life of man, when as yet undecided 
 on the profession he shall embrace, he studies, as it were, the 
 part he is to perform on the theatre of the world, and prepares 
 himself beforehand to fulfil it well. This period in the life of 
 Beclard, was marked with such indolence, as reduced his 
 family to despair; he is fit for nothing, said they, and neglect- 
 ful of the future: this was owing to their having misunder- 
 stood his secret intentions, and to the want of the aliment they 
 required; but as soon as his father was enlightened by good 
 advice, softened by the solicitations of his son, who only wish- 
 ed to become a surgeon in the army, and had permitted him 
 to follow the medical courses established in the hospital of the 
 same city, from that moment did the young student see open- 
 ed before him a profession in which he ardently desired to 
 
LIFE AND WRITINGS OF BECLARD. 
 
 enter, from that moment also ceased that torpor which had so 
 long held his faculties in chains. 
 
 He began the study of medicine in 1S14. A circumstance 
 soon presented itself, as if on purpose, to give to Beclard a 
 knowledge of his powers: a competition occurred for the first 
 time for the situation of resident physician in the hospital. 
 One of the pupils, who since has been lost in the crowd, had 
 then a reputation, we might say brilliant, for every age has its 
 kind of celebrity, and was considered as a very formidable 
 competitor; so much so as to fix the eyes of every one on 
 him, for that situation. Notwithstanding this, Beclard so as- 
 tonished his judges with the extent of his knowledge, and the 
 precision of his language, that he was proclaimed the success- 
 ful candidate. This was the first glimpse of that glory which 
 was to shine on him, even to his tomb. 
 
 During his residence in the hospital of Angers, he conse- 
 crated almost all his time to the study of anatomy -a study for 
 which he had a great predilection; he accustomed himself to 
 observe every kind of malady, which were infinitely varied, 
 and which presented themselves in an abode opened to all the 
 miseries to which humanity is subject. He habituated himself 
 to a skilful manipulation of the knife. He studied with expert 
 masters, among whom Mirault was a distinguished practi- 
 tioner, and whose name is enrolled in the pages of our art. He 
 learned, I say, to interpret with wisdom, and without preju- 
 dice, the facts which abound in our science, and from which 
 we are often exposed to draw conclusions favourable to our fa- 
 vourite opinions; finally, he received from this school, more 
 useful than celebrated, the germ of a correct knowledge, and 
 of that eclectic and rigorously exact mind which afterwards 
 rendered him so valuable a man. The example of Beclard, 
 and his success, prove, better than a long argument, the utility 
 of elementary or secondary schools of medicine, where the 
 number of pupils being small, they have a better opportunity 
 to observe for themselves, and consequently, are enabled early 
 to obtain that experience which in the larger schools, the eager 
 crowd of students never acquire but with the greatest trouble. 
 Thus we see him leaving the retired scenes of his first studies, 
 
4 LIFE AND WRITINGS OF BECLARD. 
 
 already rich in. scientific lore, if not very extensive, at least 
 very positive. 
 
 During the first years of his medical studies, he devoted 
 himself to the study of the Latin language and philosophy, 
 which the clergyman attached to the hospital taught him, and 
 who delighted to instruct a young man already so rich in 
 knowledge. He cultivated at the same time Botany; he ob- 
 tained several premiums on subjects of natural history, and by 
 his zeal, ardour, and success, from this time, gave hopes of a 
 brilliant career. Beclard, during his residence in the hospital 
 of Angers, left to his successors a noble example of emulation 
 which will be long remembered. 
 
 At this time Bichat had reached the middle course of his 
 career, and filled the learned world with his glory and his 
 name. In the many conversations young Beclard had with 
 his relations, he often remarked how happy he should be if he 
 were one day able to cope with the Father of General Anato- 
 my and become his equal. Bichat was his idol; he was anxious 
 to render homage to his genius and be considered one of his 
 followers. Unfortunately for Beclard, Bichat died before he 
 was able to attend his lectures, for it was not until 1808, that 
 he went to Paris; but he had carefully transcribed notes taken 
 at the last course of this celebrated anatomist.* 
 
 In 1808, Beclard was distinguished in the first rank of the 
 pupils of the Practical School or clinical courses, and of the 
 hospital of Paris. In 1809, premiums were conferred on him 
 by the medical school, on subjects of anatomy, physiology, 
 medical natural history, chemistry, and physicks. He was 
 soon after appointed resident physician (eleve interne,) to va- 
 rious hospitals. He again, 1810, received premiums on anato- 
 my, physiology, medicine and surgery; and Mr. Roux select- 
 ed him for the honourable office of preparing and repeating 
 lectures at the hospital of La Charite. 
 
 Hitherto, Beclard was only known to his rivals in fame, 
 and to his friends; and all his merit only consisted in a vast 
 
 * This passage alludes particularly to the work of Bichat on Pathological 
 Anatomy, which was published from an authographic MS. of Bdclard, and 
 which are the only authentic notes we possess of Bichat's last course. 
 
 TRANS. 
 
LIFE AND WRITINGS OP BECLARD. 
 
 memory and an easy elocution. His genius had not yet as- 
 sumed a determinate character; as yet, no original production 
 had unveiled his resources; but at last an important occasion 
 of distinguishing himself occurred. M. Dupuytren being ap- 
 pointed to the chair of operative surgery, the place of adjunct 
 professor of anatomy in the faculty of Paris became vacant. 
 Beclard, being appointed assistant, in 1811, he presented him- 
 self as a candidate, and to him was awarded the prize by the 
 judges. He had already acquired the esteem of a great many 
 students who had followed his private courses. He had scarce- 
 ly any reputation as an anatomist; but as soon as he saw that 
 he was surrounded with so many means of instruction, he has- 
 tened to improve himself by taking advantage of the opportu- 
 nity presented to him. Besides, he Had already indicated in 
 the thesis that he presented for the abovte mentioned situation, 
 in the most luminous manner, what ouglt to be the conduct 
 of the superintending adjunct towards tlfe pupils in the pur- 
 suit of anatomical knowledge. It was therefore expected, that 
 faithful to the principles that he himself had laid down, he would 
 not fail to put them in practice; and it is well known that he 
 did not belie the hopes, that^his zeal and precocious talents had 
 led the profession to expect. 
 
 Among the interesting facts collected by him, in the dissect- 
 ing rooms of the medical school, and which he presented to 
 the society of the professors, among whom he was very soon 
 received, we will only mention the principal ones. Such was 
 the observation of a foetus born with a frontal and very volu- 
 minous hernia of the brain, being the consequence of hydro- 
 cephalus. This preparation was rendered particularly curious 
 by the extraordinary existence of two bones situated between 
 the frontal bones and not far from their articulation with the 
 ossa nasi. 
 
 Soon after, he gave the description of a foetus, of which the 
 umbilical cord very much dilated at its base, contained a part 
 of the abdominal organs, and the heart of which adhered to 
 the palate. He published, conjointly with JVK Bonnie, a case 
 of labour per ano, of a child the conception of Which was ex- 
 tra-uterine. In a memoir on necrosis, he maintained and de- 
 
6 LIFE AND WRITINGS OF BECLARD. 
 
 veloped the opinion of some authors who think there is in 
 reality no regeneration of bone. He also made public his re- 
 flections on the formation of the callus; he demonstrated to- 
 gether with Bonn and Bichat that the ossification of the perios- 
 teum was only momentary, and served as a sheath to the two 
 fractured extremities during the time they are cemented with 
 phosphate of lime. It had been supposed for a long time, that 
 the curvature of the aorta produced the lateral curvature of the 
 dorsal region of the vertebral column. Bichat had already 
 shaken the general belief of this supposition, by supposing that 
 it might be caused by the often repeated contractions of the 
 muscles of the right arm; this however was only a supposition, 
 but Beclard demonstrated it to be a positive fact by numerous 
 researches upon this subject. We must not omit to mention, 
 the physiological experiments he performed in order to prove 
 that the foetus has respiratory movements while in the uterus, 
 by which it introduces the waters of the amnion into the bron- 
 chiae. He was, however, unable to demonstrate that this liquid 
 has a chemical action on the blood which enters the lungs. It 
 was also at this time that he made, with the assistance of Le 
 Gallois, a series of curious experiments calculated to determine 
 the action of the oesophagus in vomiting. 
 
 In 1813, B6clard defended before the faculty of Paris his 
 thesis for the degree of Doctor of Medicine; it contains seve- 
 ral propositions, which treat: 1st, of the distinction to be esta- 
 blished between the lamellated and adipose tissues; 2d, of the 
 projection and depression of bones, which he conceives to be 
 induced by the primitive formation of the cellular web of the 
 bone, and not to the traction of the tendinous attachment of the 
 muscles. Some of his labours already cited, are again pre- 
 sented in this Thesis, which concludes with a learned inter- 
 pretation and with practical observations on the method of per- 
 forming the lateral operation proposed by Celsus. His talents 
 as a surgeon had been already justly appreciated; and in 1814, 
 at the time of the first invasion of France by the allies, he was 
 appointed by government to give his professional aid to the 
 wounded soldiers brought to the ambulance, established at the 
 Hospital Saint-Louis. His Memoir on Acephalus appeared in 
 
LIFE AND WRITINGS OF BECLARD. 7 
 
 1815. He also communicated at this time, several facts of 
 pathological anatomy, that he had observed in the dissecting 
 rooms of the Practical School. 
 
 A competition then arose for the place of second surgeon 
 of the Hotel-Dieu, and Beclard, for the first time, was unsuc- 
 cessful in this kind of contention: Mr. Marjolin was his op- 
 ponent. As the two Candida* e., however, had contended for 
 the victory, with equal merit and talents, Beclard was appoint- 
 ed surgeon to the Hospital of La Pitie. He had already ac- 
 quired a considerable skill in the art of Part and of T. L. Petit, 
 under a master who loved him tenderly, and with whom 
 he was afterwards united by the most affectionate ties of friend- 
 ship. Dubois had taught him operative surgery, at the school 
 of Perfectionnement) and it is not astonishing, that Beclard 
 should have soon developed a talent truly surgical, to which, 
 however, his natural dexterity, and his daily habit of dissec- 
 tion, had already predisposed him. 
 
 In 1816, he became a member of the Philomatic Society, 
 and he gave, for the first time, a course on General Anatomy. 
 In 1817, appeared his researches on the wounds of arteries. 
 The experiments of Jones, in England, were scarcely known, 
 when our anatomist thought it proper to give them a trial, and 
 the result of his labours confirmed the conclusions drawn by 
 the English experimenter. This memoir is to be found among 
 those of the Soci&te d* Emulation, of which he was a mem- 
 ber. In 1818, he published with Mr. J. Cloquet, a transla- 
 tion of Lawrence's treatise on hernia. 
 
 It was also during the same year, that the faculty of medi- 
 cine, of Paris, received him as one of its members. This 
 memorable event in the life of Beclard, in adding new lustre 
 to his reputation, inspired him with the noble ambition of 
 rendering himself equal in talent to the celebrated professors 
 of that faculty, old in glory and experience. Thus, did we 
 see him redouble his efforts, in order to fulfil with dignity and 
 talent, the chair which had been entrusted to him. The eager- 
 ness with which the students attended his learned courses on 
 Anatomy, was the best pledge of the propriety of the selec- 
 tion the faculty had made, of this remarkable man. 
 
8 LIFE AND WRITINGS OF BECLARD. 
 
 He aided in the formation of a scientific selection then 
 known under the name of the Nouveau Journal de Medecine, 
 of which, Les archives, generales de Medecine, are now a con- 
 tinuation. In 1819, he published four memoirs on Osteosis,* 
 of which disease, he described the progress with the greatest 
 precision and perspicuity. He cooperated in the publication 
 of the Dictionary of technical terms of Medicine, Surgery, 
 Pharmacy, &c. and was one of the principal colaborators of 
 the Nouveau Dictionnaire de Medecine. 
 
 In 1820, he was appointed president of the board of Juries 
 of the department, and member of the council of health of 
 the department of the Seine. When a royal ordinance had 
 created the Academy of Medicine, (December 20th, 1820,) 
 public opinion pointed out Beclard, and he was unanimously 
 elected to fulfil the functions of secretary for life of that learned 
 body, functions that he exercised, until ministerial favour dis- 
 posed of his office otherwise. 
 
 In 1821, he published a volume of additions to the general 
 Anatomy of Bichat, and the following year gave to Mr. Des- 
 cot, the result of his experience and researches on the local 
 affections of the nerves, which the latter recorded in his the- 
 sis. In 1823, he published his Elements of General Anato- 
 my, whence students may long draw the most impor- 
 tant lessons which have hitherto been given on the organi- 
 zation of the human body. At this time Beclard was in- 
 cluded in the general disgrace of the old faculty of medicine, 
 and when the reorganization of the new school was about to 
 take place, he came very near being excluded, but his great 
 reputation and his talents got the better of every kind of in- 
 trigue and opposition which arose against him, and the chair 
 on which he had shed a new lustre, was restored to him. 
 
 This rapid recapitulation of the labours most remarkable in 
 the life of Beclard, brings us to a gloomy epoch ; but before 
 entering on this painful part of the task we have prescribed to 
 ourselves, let us return to the particulars of the life of a master 
 so dear to us and one -who honoured us, with so benevolent 
 
 * Beclard has given this name to the branch of anatomy which treats of 
 the developement of bone. 
 
LIFE AND WRITINGS OF BECLARD. 9 
 
 a friendship. Let us therefore consider Beclard, as an anato- 
 mist, as a surgeon, as a professor, and as a private man. 
 
 Anatomy had been the first object of the studies of Beclard. 
 His retentive memory enabled him to recollect most faithfully 
 the minutest descriptions ; his skill enabled him to perform 
 the most difficult dissections; and his great judgment placed 
 him far above a great number of pupils, whose whole ability 
 consists in discovering a muscle, or in following up the mi- 
 nute ramifications of an artery. Endowed with the three- 
 fold gift of dissecting well, of seeing well, and of remember- 
 ing exactly the relations and disposition of parts, he had 
 in himself, all the requisite qualifications to make a good ana- 
 tomist. When he arrived in Paris, anatomy and physiology, 
 already greatly improved by the researches and labours of 
 Haller, Bordeu, and Bichat, beautifully adorned with all the 
 brilliancy of their genius, powerfully enticed a great many 
 students, both by the attraction of the new discoveries, and 
 with the hope of the many useful applications they would be 
 able to make of them, in the practice of medicine and surgery; 
 consequently, this science was cultivated with an indefatigable 
 ardor, which was kept up and increased by the example and 
 encouragement of such men as Portal, Chaussier, and Dum6- 
 ril. At this time Pinel had already established important dis- 
 tinctions in the curative art founded on Anatomy ; and the 
 school, of which he was the leader, followed with enthusiasm 
 the impulse given by this philosophical physician. It was at 
 this time also, that the indispensable and inseparable know- 
 ledge of the organization, and that of maladies were intimately 
 united; and in order to render it still more necessary, while 
 Messrs. Richerand and Dupuytren were instructing the me- 
 dical profession with the healthy action of our organs, Messrs. 
 Bayle and Laennec were pointing out the different modes of 
 alterations they were susceptible of experiencing. 
 
 It was very natural that Beclard should eagerly embrace 
 the prevailing opinions of his age, the more so because he 
 was capable of foreseeing all the good that the science might 
 derive from it. He never confined himself therefore to the 
 dry and sterile study of descriptive anatomy; he always con- 
 
10 LIFE AND WRITINGS OF BECLARD. 
 
 sidered it in its relations with Medicine and Surgery. He 
 consecrated the whole of his time to the study of the relations 
 of the parts with each other, to the varieties of forms and di- 
 rections that circumstances may cause them to experience; 
 and not being able to find, in the immense number of facts 
 which he daily observed, means sufficiently vast to multiply 
 his learning, he was seen thirsting for more knowledge, to 
 extend beyond conception the limits of his erudition. Full 
 of admiration for the German school of medicine, to which 
 we owe so many valuable discoveries in the science of orga- 
 nization, he early familiarized himself with the labours of 
 Meckel, Oken, Tiedemann, &c. He also profited by the dis- 
 coveries of the celebrated men of Great Britain and Italy ; 
 and it was not until he was possessor of an immense mass of 
 facts gathered, so to say, from every quarter of the civilized 
 world, that he minutely and carefully scrutinized, aided by 
 his vast experience, every fact, every opinion, and every 
 theory. 
 
 Some men, envious of his glory, accused him of being a 
 mere compiler, a man of erudition, but denied that he pos- 
 sessed even the smallest particle of genius. Let us not forget, 
 therefore, that in following this course, and in fulfilling so 
 difficult a task, Beclard needed to possess a correct and rapid 
 intellect, an uncommon eclectic mind, and a very superior 
 power of reasoning. The parallel that some persons have 
 tried to establish, between Bichat and Beclard, can not really 
 exist. If these two men have between them some resem- 
 blance as to their early and rapidly acquired glory, and unex- 
 pected and premature end, they essentially differ as to the 
 manner in which they cultivated that science they have 
 equally improved. Rich with his own native genius, carried 
 along by the desire of constructing the medical edifice on a 
 new plan, Bichat hastened to arrange the materials for 
 which he was almost entirely indebted to his own researches. 
 B6clard, on the contrary, formed in his mind the vast project 
 of collecting all the scattered facts belonging to the science, 
 in order to create with them a code of doctrines authorized 
 by the most celebrated names, and supported by the result of 
 
LIFE AND WRITINGS OP BECLARD. 11 
 
 the meditations of the most learned men. B6clard preferred 
 the merit of making truth shine, it mattered not from what 
 quarter it proceeded, to the dazzling glory of being an inven- 
 tor. He was unaffectedly the greatest admirer of Bichat, and 
 if he has often been obliged to controvert his opinions, it was 
 because the interest and the advancement of the science de- 
 manded it. 
 
 The same distinction which has been made between Bos- 
 suet and Massillon, might be established between Bichat and 
 Beclard. The Bishop of Meaux was one day preaching 
 to an illustrious auditory ; Massillon, who was listening to 
 him, said, " This is very well, I admire him ; but, if I were 
 in his place, I should preach otherwise." Such was the con- 
 duct of Beclard with respect to Bichat. Cooler and less en- 
 thusiastic, he came after him, as it were, to correct the errors 
 which had passed unnoticed by the inventive genius of that 
 great man. Let us therefore cease to establish between them 
 a comparison which does not permit us to judge of either, ac- 
 cording to his respective merit. They are only to be consid- 
 ered singly, and then their individual merit will cause us to 
 admire them the more. 
 
 It is in consequence of this plan of reform and improve- 
 ment, that Beclard first published a new edition of Bichat's 
 General Anatomy, with a volume of additions, and in the 
 same spirit of improvement, he afterwards brought to light 
 his Elements of General Anatomy, a work remarkable for 
 its clearness, the great number of truths it contains, the ex- 
 tensive plan on which it was written, and the immense erudi- 
 tion therein displayed. This work has been compared to the 
 Manual of General, Descriptive and Pathological Anatomy of 
 Meckel. It is very true that the French anatomist has been 
 sometimes benefited by this great collection of facts more or 
 less interesting ; but how much the imitator has surpassed his 
 original ; with what art he has avoided those German ideas, 
 those hypothetical explanations, and those often far fetched 
 analogies with which the General Anatomy of Meckel is in- 
 terspersed. On the other hand, the work of Beclard is com- 
 pared to that of Bichat, the enchanting style of which is con- 
 
13 LIFE AND WRITINGS OF BECLARD. 
 
 tinually praised ; but we must not forget that Bichat wrote at 
 a time when it was necessary to entice the reader by the charm 
 of diction, while Beclard wrote for sober men, whom science 
 alone can seduce, without the artifice of meretriciousornaments. 
 Beclard carries in himself the distinctive marks of his age. 
 Bichat has written, as is said, the romance of the science, but 
 Beclard has striven to fix its laws, and to draw up its code. 
 Thus, the General Anatomy of Beclard possesses its peculiar 
 merit, and may be considered as one of the most glorious 
 titles of the author to immortality. To conclude, this learned 
 man has especially studied and improved anatomy, in its re- 
 lations with medicine and surgery, and by strengthening the 
 foundation of this science with an unlimited erudition, has 
 really founded a school, the principles of which will be long 
 followed. 
 
 To the valuable qualities that we have just enumerated, Be- 
 clard added those of a skilful operator. He was endowed 
 with a steady presence of mind, with a firmness which 
 never approached harshness, and with a dexterity which was 
 the result of his many dissections. Unforeseen circumstan- 
 ces sometimes obliges the operator to deviate from the general 
 rules of the art. Beclard, on these occasions, knew how to 
 modify a method, or invent a new one to suit the case. His 
 composure never abandoning him, his memory recalled, or his 
 genius often suggested to him, during an operation, every 
 thing requisite to insure its success. He has invented or im- 
 proved the methods of several operations: such are his method 
 for curing the fistula of the duct of steno ; several methods 
 for the partial amputation of the foot, the amputation of the 
 articulation of the metatarsus, the amputation of the articulation 
 of the shoulder and hip joint. He has also modified the man- 
 ner of cutting through the soft parts in amputating limbs, 
 and the method of sawing the tibia in the amputation of the 
 leg. He was the first who removed the parotid gland;* finally 
 
 * It is strange we should so often read of European surgeons extracting 
 this gland, while in this country some of the greatest authority in surgery 
 deny the possibility of the operation. On the one hand, we can not sup- 
 pose that these surgeons wish to impose on us, and on the other, to say 
 
LIFE AND WRITINGS OP BECLARD. 13 
 
 he modified to great advantage the method of Celsus in the 
 lateral operation. 
 
 His vast erudition was equally extensive in surgery. In 
 his lectures, delivered at the Hospital of La Piti6, he gave 
 unquestionable proofs of an extensive and solid knowledge. 
 Even those who confined themselves to his course of lectures 
 on surgery, and who disdained to attend his operations, ex- 
 hibited on a very modest theatre, could not, at least, deny him 
 the merit of being extremely well versed in Surgical litera- 
 ture. He was always the general admiration of his audience, 
 in seeing with what extraordinary talent he developed and 
 commented on the theories of those men who have written on 
 this branch of the healing art. It is useless to endeavour to 
 avenge here Beclard for the character with which he was re- 
 proached, of being a surgeon only in theory. Let us not 
 mingle with the pleasure we experience in recording the merit 
 and talents of this excellent man, the bitter remembrance of 
 the numerous persecutions and ridiculous cabals, of which he 
 was the object. The reputation of Beclard, as a professor, 
 was spreading more and more every day. He possessed the 
 very rare faculty of presenting methodically, with precision 
 and simplicity, all that his extraordinary memory had retain- 
 ed. He was particularly happy in the selection of his words 
 and in the construction of his phrases. He preferred preci- 
 sion and vivacity of expression to elegance. His language 
 was parsimonious of metaphors ; but he developed his ideas 
 by a gradation of words admirably chosen, so that the last ex- 
 
 that such great anatomists as Beclard, and a great many other European 
 surgeons, such as Speranza, Lisfranc and others who published, having re- 
 moved the parotid, have been mistaken, and that they have only extracted 
 an enlarged lymphatic gland, is more than we are disposed to assert. That 
 this may have been sometimes the case, I entertain no doubt, for three years 
 ago, Dr. Gibson performed an operation which, as he correctly observed, 
 might have been palmed on a class of students, as being an operation for the 
 removal of the parotid, whilst it was only an enlarged lymphatic r nd. But 
 at the same time, if any reliance is to be placed on the word 01 aJeclard, I 
 think we can not deny him the glory of having performed this difficult 
 operation. TBASS. 
 
14 LIFE AND WRITINGS OF BECLARD. 
 
 pression being the most impressive and the most energetic, 
 left in the mind of his audience the image of the object, or 
 the idea deeply impressed. He slowly prepared, and for a 
 longtime matured his lessons ; being perfectly master of the 
 subject on which he was about to lecture, he never was in the 
 least embarrassed before his pupils. He always united there- 
 suit of his own meditations, to the knowledge he had acquired: 
 he interested and captivated his hearers without having re- 
 course to a vain show of language, by which the deceived 
 multitude is sometimes seduced. 
 
 In his last course he gave an anatomical and physiological 
 history of the nervous system ; a delicate and truly difficult 
 subject. Nevertheless, his descriptions were so very clear 
 and there was in them so much order, that it was impossible 
 not to understand his lectures. He has presented with the 
 greatest perspicuity the endless opinions advanced on this 
 subject from Praxagoras down to this present time. His lec- 
 tures were now more attractive and more instructive than 
 ever, and as if presageful of his approaching end, he always 
 lectured more than the time allotted to him, and could not 
 withdraw from that chair, which soon a funeral mantle was 
 to shade. 
 
 If Beclard had his equals in some branches of the healing 
 art, as a lecturer he was surpassed by none ; but on the con- 
 trary he eclipsed most of his cotemporaries. He reminded 
 us of the knowledge and eloquence of Halle, and was at least 
 equal to Cuvier, whom, however, he delighted to imitate, and 
 to the height of whose reputation he, by his vast know- 
 ledge, was every day attaining. He failed only in one respect, 
 and that was, his not being able to draw, and in so doing to 
 render even more striking his descriptions ; had Beclard pos- 
 sessed this talent, he would have been the most astonishing 
 professor, that the medical sciences had ever had as their in- 
 terpreter, till the present time. 
 
 It is not common to meet with the virtues which adorn a 
 private character united to great talents ; because ambition, the 
 ordinary source of our misdeeds, often accompanies genius, 
 and by wishing to gratify that, we are exposed to deviate 
 
LIFE AND WRITINGS OF BECLARD. 15 
 
 from the rules of social morality. This can not be said of 
 Beclard. If he desired to occupy a distinguished rank among 
 his fellow men, it was never at the expense of those who fol- 
 lowed the same career as himself, that he attained it. His 
 success in the numerous competitions he had for various offi- 
 ces, had distinguished him from the multitude, and he main- 
 tained himself in the elevated rank he occupied, by his person- 
 al merit, and his indefatigable labours. He has been" accused 
 of being ambitious ; but his noble emulation was ill inter- 
 preted ; if he desired to become rich, it was the better 
 to relieve a numerous family, of which he was the glo- 
 rious support. Could a man be ambitious, who delivered 
 public lectures for more than two thirds of every day, thus 
 neglecting to seek a practice that his great reputation could 
 not have failed to procure him? Simple and modest in his taste 
 and habits, he delighted to live quietly in the bosom of a family 
 that several kinds of talents contributed to render illustrious. 
 
 Beclard was naturally melancholy and^gloomy. His health, 
 exhausted by long continued studies, demanded the greatest 
 care. Always intensely occupied with abstract ideas, his 
 manner at first was cold, and his conversation very laconic; 
 but if by any means he was enticed away from his favourite 
 meditations, then his mind was perceived to be ornamented 
 with the lore of philosophy and history, and to possess" all 
 those charms which a man remarkable for the brilliancy and 
 variety of knowledge can infuse into his conversation. His hi- 
 larity and cheerfulness appeared only at intervals and quickly 
 vanished; an irresistible charm seemed soon to recall him to 
 the habitual sphere of his thoughts. For some time past, 
 he had given a great deal of his leisure to the perusal of works 
 on philosophy and political economy; he had also bestowed 
 much time on the study of languages, so that he was able to 
 make in society a display of another kind of merit very differ- 
 ent from that with which he obtained the applause of the medi- 
 cal profession. 
 
 Beclard was benevolent without ostentation. A great many 
 students received from him benefits of every kind, and he 
 often left them ignorant whence they proceeded. He more 
 
16 LIFE AND WRITINGS OP BECLARD. 
 
 than once abandoned to some of his pupils his discoveries and 
 medical opinions which soon created and supported their repu- 
 tation, and who afterwards became an honour to their illus- 
 trious master. He zealously aided them in their studies, and 
 encouraged their labours; he was prodigal of the wealth of his 
 immense erudition, and assisted them with the greatest zeal 
 in the cultivation of a science of whicn he ardently desired to 
 see the limits extended. 
 
 It was in the midst of so many useful labours, and when he 
 began to enjoy a reputation, which, though already great, 
 was yet onlj T dawning, that the celebrated professor of whom 
 we have just sketched the life, was seized with a mortal disease. 
 On the 6th of March, 1825, an erysipelitous inflammation 
 appeared on his face, which soon spread over the integuments 
 of the cranium. From its first appearance a cerebral exalta- 
 tion had manifested itself, and inspired the greatest fears for 
 the life of the patient. Notwithstanding all the most atten- 
 tive cares, the malady advanced with a frightful rapidity, and 
 on the 16th of March, Beclard was no more. 
 
 During the prolonged delirium which terminated his life, 
 his intellect had acquired an astonishing activity. More than 
 once we observed him, while in this state, supposing himself 
 in the presence of a large audience, and developing with a sur- 
 prising energy, ideas which, although incoherent in them- 
 selves, nevertheless disclosed the powerful and elevated mind 
 which gave them birth. They were, in a manner, the last ef- 
 forts of his expiring genius. Finally, after a long and painful 
 agony, he breathed his last in the arms of numerous friends, 
 that were bound down with grief at his bed side. As soon as 
 the news of his death reached the School of Medicine, the pu- 
 pils who for several days previous had been constantly moving 
 about his house, in order to learn the state of his health, these 
 same pupils who not long since saluted with general applause 
 their learned and modest professor, were now deeply afflicted, 
 and bitterly lamented the loss of so valuable a teacher. 
 
 On the 17th of March, 1825, the day of his burial, two 
 thousand students met at his house, and would not permit 
 other hands than theirs, to carry to their last abode his pre- 
 
LITE AND WRITINGS OP BECLARD. 17 
 
 cious remains. They themselves transported the body of Be- 
 clard to the church of Saint Sulpice, which in an instant was 
 filled with SavanSj professors, and students. It was with the 
 same eagerness, that the students, desirous of paying a last 
 mark of respect, admiration, and gratitude to their teacher, 
 carried his remains to the burial ground of Pere-La-Chaise. 
 Those who could not have the honour of bearing this precious 
 relicks, followed it in a mournful silence. In this manner it 
 may be said, that he had a more imposing attendance than the 
 ordinary and paid for pompous display, which surrounds the 
 funeral car of the rich and powerful. 
 
 The Royal Academy and the School of Medicine, appointed 
 a man of known eloquence to celebrate the last honours due to 
 the manes of Beclard. The pupils, on their side, desirous of 
 giving to their master an everlasting pledge of their sorrow, 
 opened immediately a subscription to erect a funeral monu- 
 ment to his memory. The School of Medicine of Paris, and 
 the friends of Beclard, imitated the generous impulse of his 
 younger admirers, and we soon beheld rising over his grave, 
 a monument which will long recall to our minds the talents of 
 Beclard, the universal regret of which he was the object, and 
 the noble admiration of studious youths for the teacher to 
 whose lessons they had listened with so much eagerness; and, 
 who, victim as he was of his ardour for acquirements and zeal 
 for public instruction, died when only 39 years old, and when 
 he was about to reach the zenith of his glory.* 
 Paris, December 15th, 1826. 
 
 * While the School of Medicine of Paris was deploring'the loss of Beclard, 
 the city of Angers, not less afflicted with so fatal an event, wished also to 
 honour the memory of a man who had done so much for the glory of his 
 country, appointed M. David his countryman and friend, and equally cele- 
 brated in his art, to execute in marble the bust of the rival of Bichat 
 

 
INTRODUCTION, 
 
 1. The object of anatomy is the study of organized bo- 
 dies ; it is the science of organization, and all organized beings 
 are the subject of it. Man, the most complicated of all be- 
 ings, is the principal subject of this science. The special aim 
 of Anatomy, is the knowledge of the human body, of the 
 different parts of which it is composed, and of the relations of 
 these parts with respect to each other. 
 
 Comparative anatomy, which might have been very well 
 called general anatomy, embraces all organized bodies; it has 
 for its object to seek, by comparison, which parts they possess 
 in common, and in what they differ from each other. Phy- 
 totomy is the general anatomy of vegetables, that of animals 
 is called Zootomy. Anatomy is still called general, when it 
 treats of a class, a genus, or of any group whatsoever of orga- 
 nized beings ; as for instance, that of domestic animals, or 
 veterinary anatomy. Special anatomy has for its object one 
 single species of organized bodies ; such is the anatomy of 
 the Elephant, Horse, Man, &c. 
 
 In the anatomy of man, the expression general anatomy 
 has another acceptation, which will be mentioned hereafter ; 
 but we must first give a correct idea of organization in gene- 
 ral, and of the bodies which are endowed with it. 
 
 SECTION I. 
 
 OP ORGANIZED BODIES. 
 
 2. The endless science, called Natural Philosophy, or 
 physics, the science of nature, treats of bodies which are ex- 
 
20 INTRODUCTION. 
 
 tended and moveable beings. They may be considered under 
 two different points of view: in a state of quiescence and in 
 that of motion or action. While we consider objects with re- 
 ference to the first of these, we particularly observe their form, 
 either external or internal; it is to this kind of study, some- 
 times termed Morphology, that anatomy belongs. The se- 
 cond, to which is generally affixed the name of physics, treats 
 of their appreciable changes, i. e. of their phenomena or 
 movements, either as masses, or as molicules, and for this rea- 
 son is divided into two principal branches, Mechanics and 
 Chemistry. 
 
 3. Bodies which have common or general properties, 
 vary, however, in many respects. Organization and life con- 
 stitute a very distinctive character which divides them into 
 two very different series; that of inorganic bodies, and that 
 of such as are organized and living. 
 
 4. It would be useless to dwell longer on inorganic bo- 
 dies, which not having a complicated structure, and their par- 
 ticles being entirely independent of each other, can not con- 
 sequently form the subjects of anatomical consideration. It 
 is sufficient to say, that the movements or phenomena of mass- 
 es executed by these bodies, the object of mechanics, are 
 reproduced with a regularity and constancy which permit us 
 not only to observe them, to produce and repeat them in ex- 
 periments, to determine the laws by which they are produced, 
 but to submit them to a mathematical analysis: that the moli- 
 cular phenomena of these same bodies, the object of chemis- 
 try, may be observed, and may be produced or determined at 
 pleasure by experiments; that certain laws, according to 
 which they are produced, may also be deduced from actual 
 observation and experiments; but that these phenomena are 
 yet beyond the reach of calculation, an instrumental science 
 so well adapted to hasten the progress of those to which 
 it can be applied. The science of organization and of life, 
 is nearly confined to the laws of observation. 
 
 5. Anatomy treats only of organized and living beings. 
 Besides the characters which they possess in common with 
 inorganized bodies, they have others which are peculiar to 
 
OF ORGANIZED BODIES. 21 
 
 themselves, and which modify the former: they have organi- 
 zation and life. They have each of them a special and un- 
 alterable form, ordinarily rounded, which is apparently owing 
 to the fluids they contain. Their internal form or structure, 
 presents, in fact, a mixture of heterogeneous parts, some solid, 
 and some fluid. The solid parts are called organs, which 
 means instruments, because of the action they exercise. Their 
 particles are intertwined, interwoven tissues, their arrange- 
 ment also being called texture; they are areolar, spongy, or 
 form special cavities, which contain the fluids. These parts 
 may be generally extended or elongated, and are endowed 
 with elasticity. When these parts, or organs are multiplied, 
 as is commonly the case, each one has its determinate form, 
 its peculiar texture, and its proper situation. The liquids, or 
 humours, are contained in the solids, and penetrate through 
 every part. All the parts, be they solid, or fluid, are held in 
 a mutual and necessary state of dependence upon each other; 
 and it is from their union, that organized bodies originate. 
 The solids and fluids have an analogous composition; they 
 contain much water, and some particular combinations, or 
 proximate materials, and may be almost entirely resolved into 
 gas. The substances composing them, have nothing peculiar; 
 they are also to be found in the inorganic bodies whence they 
 have been drawn, and the line of demarcation, which distin- 
 guishes organic from inorganic solids, consists less in their 
 nature than disposition. It is erroneously asserted, that the 
 matter of organic solids differs materially from inert matter; 
 for oxigen, hydrogen, carbon, and in a great many azote, and 
 some earthy substances, are the ultimate elements of them 
 all. 
 
 It is to this peculiar form, to this structure, common to 
 every living body, this areolar or net-work-like tissue, con- 
 taining liquids in greater or less abundance, and of the same 
 nature as itself, that the appellation of organization has been 
 given. 
 
 6. We understand by life, the phenomena peculiar to or- 
 ganized bodies taken as a whole. Life consists essentially in 
 this fact, that all organized bodies during a determined period, 
 
22 INTRODUCTION. 
 
 are centres penetrated by foreign substances which they appro- 
 priate to themselves, and from which issue others that become 
 foreign to them. In this movement of momentary formation, 
 the matter of the body changes continually, but its form still 
 remains. It is in the liquid state that foreign substances pene- 
 trate organized bodies ; it is also in the state of fluidity that 
 the superfluous molecules are cast off. The liquids and solids 
 are incessantly in motion during organization; the liquids tra- 
 versing the cavities of the solids, while the latter, by their 
 dilatation and contraction, produce the greater part of the 
 movement of the former. They continually change the con- 
 stituent parts of one into the other, part of the moving fluids 
 becoming for a time solids, while some solid parts are con- 
 verted again into liquids, which exchange perfectly agrees 
 with the analogy of their composition. Organized bodies ex- 
 perience changes during the whole course of their existence : 
 and from the moment of their origin they increase their di- 
 mensions and density. This latter kind of mutation contin- 
 ues until the structure of the body being insensibly altered, 
 the vital movement languishes and at last stops, which consti- 
 tutes death; after this, the elements which composed the or- 
 ganized body separate, and form new combinations. Each 
 organized body having not only its external form, but its 
 own peculiar structure, each of these parts contributes by its 
 action to the general result. The appellation of function is 
 given to the action of each organ, or to the combined actions 
 of several having the same end. 
 
 Nutrition, a function comprising absorption, assimilation and 
 excretion, of which we have just spoken, is not the only phe- 
 nomenon common to organized bodies; generation is another 
 equally as general, and without which species could not exist, 
 death being the necessary consequence of life. Every organ- 
 ized and living body originates from one resembling itself, and 
 each produces its like. In order to accomplish this object, a 
 part of an organized body which had already attained its full 
 size, having received from it the materials for its own growth, 
 separates from it and produces a being in every respect similar 
 to its parent, and presenting the same phenomena. This part 
 
0V ORGANIZED BODIES. 23 
 
 is called germ as long as it forms a portion of the body of the 
 parent. This latter general phenomenon is only a consequence 
 of the former. As long as the germ makes a part of the body 
 of the parent, it is nourished and grows as one of its organs; 
 its separation constitutes a kind of excretion. 
 
 Most of the organized bodies also reproduce parts of which 
 they may be deprived; they likewise repair to a certain ex- 
 tent the lesions that they experience. 
 
 The mass of individuals born of the same parents, and of 
 those which resemble them as much as they themselves are 
 like to each other, constitute a species. External circum- 
 stances, such as the atmosphere, food &c., as they are more or 
 less favourable, influence organization and its phenomena: 
 hence results a greater or smaller degree of perfection in the 
 development, and differences of similitude, generally, some- 
 what limited between the individuals of the same species; and 
 this constitutes the varieties. From this also results various 
 individual alterations in organized and living bodies: these al- 
 terations of organization and of its phenomena constitute 
 disease. 
 
 This series of phenomena is common to all organized bo- 
 dies, and may be summed up in the following manner: The 
 origin is derived from a being similar to itself, the end ter- 
 minates by death, the maintenance of the individual is ob- 
 tained from nutrition, the continuance of the species by gene- 
 ration; in a word, it is the reception of an action of momentary 
 formation, exercised in a body which has received its princi- 
 ple from a parent, and transmits the same to its offspring, that 
 is called life. 
 
 The two characteristic marks, which essentially distinguish 
 organized and living bodies, and which are common to all and 
 peculiar to them alone, are organization and life. 
 
 7. The form and the action of organized and living bodies, 
 organization and life, are so closely connected, that whenever 
 we observe the one we may be certain of the existence of the 
 other; indeed the one always pre-supposes the other. We 
 never observe life but in organized bodies, and we never ob- 
 serve organization but in living bodies. In fact, in order that 
 5 
 
24 INTRODUCTION. 
 
 life might exist, it was necessary that there should be solids 
 to preserve the form and fluids to keep up motion, in a word, 
 an organization; and inprder that the latter should be enabled 
 to exist in the midst of causes, all tending to its destruction, 
 it was requisite that there should be a continual motion and 
 renewal of its parts. Organized bodies are born alive from 
 bodies alike to themselves, i. e. they are viviparous; in all, 
 and during the whole term of their existence, the vital phe- 
 nomena are in exact proportion to the state of organization; 
 and when this latter is altered, either from the mere fact of 
 possessing life, or from accidental circumstances, life lan- 
 guishes and ceases, and organization is destroyed by the che- 
 mical action of its own elements. Among all those who ob- 
 serve the phenomena of nature, no one has ever been able to 
 detect matter in the very act of organizing itself, or life estab- 
 lishing itself, either spontaneously or by external causes, else- 
 where than in bodies, already living and organized. Life, in 
 fact, does not solely consist in a reunion of molecules which 
 were before separated, as occurs in the case of chemical at- 
 traction, nor simply in an expulsion of the elements previous- 
 ly combined, as in that which is produced by the repulsive 
 action of caloric; but in a movement of temporary formation, 
 in which some elements remain united, which would sepa- 
 rate should life cease, and in which the elementary parts are 
 separated, without the action of caloric; now, this vital action 
 exists only in organized bodies. This close and reciprocal 
 connexion of organization and life, is the reason why they 
 have been by turns considered as being the cause or the ef- 
 fect of each other. This, doubtless, is wrong; organization 
 and life are a complex idea, which should no more be divided, 
 (unless abstractedly), than these two things themselves, which 
 are inseparable. Life is organization in action, or, according 
 to the happy expression of Stahl, is the organism. The ob- 
 ject of this work, however, being the examination of orga- 
 nization in a state of rest, life will be merely alluded to.* 
 8. Organized bodies having a heterogeneous structure, 
 
 * See Richerand's Elements of Physiology. 
 
OF ORGANIZED BODIES. 25 
 
 their history is composed of that of their various parts; and 
 and it is properly this study which is the object of anatomy. 
 The physical state of these bodies does not only embrace me- 
 chanical or chemical phenomena, but also those which belong 
 to them in proper, and which are not possessed by inorganic 
 bodies, viz: nutrition and generation, i. e. the organic or vi- 
 tal actions. These particular physical laws assume the name 
 of physiology. 
 
 Anatomy* then may be defined the knowledge of organized 
 bodies, or the science of organization. According to its ety- 
 mology, this word has another signification: it simply means 
 dissection; but it has been consecrated by custom, and it is 
 preferred to the words morphology, organology, (a discourse 
 on form, organs), that have been proposed as substitutes. 
 Anatomy, in fact, is a science of mere observation, and dis- 
 section is the principal means by which we expose the parts 
 of organized bodies in order to be able to observe them. 
 
 Physiologyt is the knowledge of the phenomena of orga- 
 nized bodies, or the science of life; it is also sometimes call- 
 ed Zoonomy, (laws of life,) and biology, (discourse on life). 
 Physiology, like anatomy, is a science of observation; but it 
 treats of the phenomena of organized and living bodies. 
 
 Anatomy and physiology are closely connected; having 
 been taught by observation, that organization and the pheno- 
 mena of life are always in a reciprocal relation, we may infer 
 the condition of the one by the state of the other. 
 
 9. Organized and living bodies, the subjects of anatomy 
 and physiology, are divided into inanimate beings, or vegeta- 
 bles, and animals or animated beings; this division is derived 
 from the well marked difference existing between animals 
 and vegetables of a complicated organization, but is very little 
 so, among those the organization of which is the simplest of 
 all. 
 
 10. The most complicated vegetables are generally form- 
 ed of two distinct parts, separated by a median horizontal line, 
 one descending, and contained in the earth, is the root; while 
 
 * From hva.Ttfj.vcDy I dissect. 
 
 f From <j>y<n?, nature, and x&>o?, discourse. 
 
INTRODUCTION. 
 
 the other ascending and surrounded by the atmosphere, is the 
 stem, body, or tree which bears the leaves and flowers. Their 
 structure consists, simply, in an areolar tissue, vessels and spi- 
 ral tubes, which are called tracheae. They possess no other 
 organs than those of nutrition and generation. Their most 
 important and vital parts are all situated externally. Their 
 chemical composition is rather simple; nitrogen is seldom met 
 with in them, and if found at all, it exists only in some par- 
 ticular part. Their vital action is confined to their growth 
 and reproduction. Their nutrition, the materials of which 
 are drawn from the earth and atmosphere, from water and air, 
 consists in an absorption induced by the roots, by a move- 
 ment of translation that the liquids experience in the vessels 
 of the stem, and in a kind of respiration which occurs prin- 
 cipally in the leaves: in these various actions vegetables re- 
 tain hydrogen and carbon, little or no nitrogen, and ex- 
 hale the superfluous oxygen. Their reproduction is induced 
 in divers manners. There is, moreover, in the organization 
 of vegetables, a very great diversity, which can not be pro- 
 perly treated of in this work. 
 
 OF ANIMALS. 
 
 11. Animals, at the head of which is man, who 
 closely resembles some of them, besides the general charac- 
 ters of organized bodies, have others which are peculiar to 
 themselves, which consequently distinguish them from vege- 
 tables, and which have an influence on, and modify the for- 
 mer. But animals are so very different from each other, that 
 their characters, which may be said to be common, are nei- 
 ther very numerous, nor very distinct. The following are 
 those peculiar to animals, some few of which are common to 
 all, and others are more or less general. 
 
 Besides the rounded form which belongs generally to all 
 organized beings, we observe that the greater number of ani- 
 mals are, at least externally symmetrical and divided by a 
 median vertical line, into two lateral and similar halves, and 
 that their length in this direction, is greater than in any other 
 of their dimensions. The liquids greatly predominate over 
 
OP ANIMALS. 27 
 
 the solids. The areolar or cellular tissue, which forms the 
 greater part of the body, is very soft and contractile. The body 
 is traversed by an internal cavity, in which the aliments are 
 received. This cavity as well as the exterior surface, is invest- 
 ed with a membrane or skin which limits and envelops the 
 remainder of the body. There are in many animals circulating 
 vessels which convey, in certain determined directions, the 
 nutritive substance found in the intestine, into every part of 
 the body; organs of respiration, in which this matter is sub- 
 mitted to the action of the atmosphere, and secretory organs, 
 in which a part of this matter is separated from the mass. 
 They have genital organs which generally consist in a cavity 
 from which the germs are detached and expelled. Finally, 
 in most animals, there are muscles to execute the apparent 
 movements, senses to receive the impressions of external ob- 
 jects, and a nervous system consisting in cords or filaments, 
 having one of their extremities immersed and expanded in the 
 integuments and muscles, and the other swelling into enlarge- 
 ments or ganglia more or less considerable. 
 
 12. The solids, or organs of animals, have for their prin- 
 cipal base the cellular tissue, a soft, extensible and contractile 
 substance, easily permeated by liquids. Condensed on the 
 two surfaces of the body, it forms on the exterior, the skin, 
 and on the interior, the mucous membranes or the internal 
 skin. It is this very same membrane, the skin, variously dis- 
 posed, which constitutes the organs of respiration, secretion 
 and generation. It also forms the senses. Hollowed into 
 ramified canals, in the parietes of which it possesses a consi- 
 derable consistence, the cellular tissue constitutes the vessels. 
 This same substance variously modified, without losing how- 
 ever its distinctive characters, forms also several other kinds 
 of organs in animals. The muscular fibre constitutes a second 
 kind of solid, essentially differing from the cellular tissue, be- 
 cause in the midst of this soft substance which forms the com- 
 mon mass, linear series of microscopic globules are to be ob- 
 served; this muscular fibre contracts whenever irritated. The 
 substance of the nerves is formed also of globules, but different 
 from those which compose the muscles; it transmits to nervous 
 
28 INTRODUCTION. 
 
 centres the impressions received, and to the muscles the in- 
 fluence of the same nervous centres. 
 
 The animal fluids or humours are numerous and in abun- 
 dance. In most animals there is a liquid in circulation in the 
 vessels; it is the blood, which is the principal and most im- 
 portant part of the nutritive liquids; other liquids are absorbed 
 from the surfaces or the mass of the body itself, and others, 
 finally, are secreted or separated from the blood. This latter 
 essentially consists in a very abundant serous vehicle, in which 
 are immersed microscopic bodies similar to those observed in 
 the solids. The composition of the blood is altogether analo- 
 gous to that of the solid parts, and a simple change of state, or 
 some small change in the proportions of the componing ele- 
 ments, are sufficient to produce the conversion of the liquids 
 into the solids. 
 
 The ultimate anatomical elements of the humours and of 
 the organs of animals, appear then to be simply an amorphous 
 substance, liquid in the blood in which it constitutes the serum 
 or the albumen, and concrete in the organs in which it con- 
 stitutes the cellular tissue, and a substance under a globular 
 form, or globules freely floating in the blood, and stationary in 
 the organs where they form the muscular fibre and the nervous 
 substance. The chemical composition of the animal body is 
 more complicated than that of vegetables, and consist in more 
 volatile elements. This is the reason why nitrogen enters into 
 their composition as a very essential part, and is mixed with 
 the other general elements of the organization. Lime is the 
 earthy element most generally found in it. 
 
 13. The general organic phenomena, such as nutrition and 
 generation, are met with in animals, but modified by the phe- 
 nomena which are peculiar to them. Nutrition, instead of be- 
 ing the result of external absorption alone, is induced at the 
 same time, and principally from an internal absorption which 
 occurs in the intestinal cavities. The nutritive fluid taken up 
 in the intestines is submitted to the action of the atmosphere; 
 the result of this respiration, is a production of water and car- 
 bonic acid, which result is precisely the contrary of what hap- 
 pens in vegetables. Besides this, the nutritive liquid needs 
 
OF ANIMALS. 29 
 
 to be continually purified from all superabundant and extrane- 
 ous substances, by means of secretion. They occur on the ex- 
 ternal and internal surfaces, sometimes through the gaping 
 orifices of vessels opening on large surfaces, which permit the 
 secreted liquid to ooze out; while at others it is from the bot- 
 tom of small cavities formed in the skin or in the mucous 
 membrane, that we perceive this percolation; again, we ob- 
 serve the circulating vessels communicating with proper ves- 
 sels or ramified excretory canals, which are also formed by the 
 envelope of the body, and which pour out the secreted liquid. 
 Among the liquids which are the result of secretions, some 
 are necessary to the exercise of functions, others are entirely 
 rejected as superfluous and extraneous, which constitutes a kind 
 of depuration. The nutritive fluid continually supplied by in- 
 testinal absorption, maintained in a proper state by respira- 
 tion and secretions, is sent into every part of the body, und 
 there effectuates nutrition, a wonderful process in which this 
 fluid is decomposed in such a manner, that in every part of 
 the body a portion of the blood becomes solid, and constitutes 
 an integral part of the organ; when at the same time, and in 
 every part also, a portion of the organs returns to a liquid state, 
 and again enters into the vortex of the circulating fluid. 
 Generation, or the production of a new being, is so diversified 
 in its modes, that it presents no distinctive character peculiar 
 to animals and common to them all. The separation of the 
 sexes, which is subordinate to motion, is in fact, neither peculiar 
 nor common to the animal kingdom. Animals possess also the 
 power of reproducing by a kind of vegetation, certain parts 
 when they are removed, although in a smaller degree than 
 vegetables. 
 
 14. Muscular motion, sensations and nervous action, give 
 to animals, in a manner, a new life. These functions have 
 consequently received the appellation of animal life, in op- 
 position to the other functions called organic or vegetative 
 life. The impressions produced by external agents on the or- 
 gans of sensations, i. e. on the external or internal skin, or in 
 a peculiar manner on some of their organized parts, induce in 
 these organs actions which are transmitted by the nerves to 
 
30 INTRODUCTION. 
 
 the central masses of the nervous system. There does not 
 exist a single part of the body, which, under certain circum- 
 stances, may not be the seat of some sensation. When the ani- 
 mal has received a sensation, and that excites in him a voli- 
 tion, it is also through the nerves that this volition is trans- 
 mitted to the muscles, the contractions of which produce the 
 movements of the animal. 
 
 The nervous action is not confined to transmitting the im- 
 pressions received by the senses and the volition to the mus- 
 cles; for, the nervous central masses are also the organs of in- 
 stinct and of the cerebral functions. 
 
 The functions of which we speak are not only superadded 
 in animals to the organic or vegetative functions, but they sin- 
 gularly modify the exercise of the latter. Thus in nutrition, 
 the introduction of the aliments is generally produced by mus- 
 cular movements; the muscular fibres which form a coat to 
 the intestines, is also the cause that the aliment they contain is 
 moved on in this tube; it is also a set of muscles, which, in 
 many animals, are placed at the point and centre of reunion 
 of all the vessels, which propel the blood; and it is muscles 
 also which induce, by their movement, the introduction into 
 and diffusion of air in the respiratory organ. There are 
 senses placed at the entrance of the organs of nutrition. 
 Nerves are also distributed to the organs of nutrition, and al- 
 though in an ordinary state these nerves transmit neither 
 sensation nor volition, and movements are suddenly deter- 
 mined in them by impressions or irritations, nevertheless, in 
 powerful affections of the nervous centres, the movements are 
 interrupted, and in a pathological state these functions are ac- 
 companied with sensations. Generation is like nutrition, mo- 
 dified in its actions by the animal functions. 
 
 15. There is, in fact, between all the organs, and between 
 all the functions of animals, a connexion which exists in all 
 organized and living bodies, but which is still more remarka- 
 ble in animals, and especially in some of them. In organized 
 beings, which possess only nutrition and reproduction, the 
 latter of these functions is the consequence of the former. 
 In animals which enjoy motion and sensation, nutrition must 
 
OF ANIMALS. 31 
 
 be executed by digestion, for the animal could not at the same 
 time possess the power of locomotion, and be fixed; genera- 
 tion in this case is sexual. In proportion as each order of 
 functions becomes more complicated, the organs superadded 
 to those, whose existence is more general, hold the for- 
 mer under their control. Thus, for instance in the order of 
 the nutritive functions, the circulation, and in the latter, the 
 action of the heart, which is not as common as the other nu- 
 tritive phenomena, keep, when they exist, all the others under 
 their influence. In the same manner, in the animal functions, 
 the action of the nervous centres holds in subjection those 
 phenomena, whose existence is more generally met with in 
 organized beings. The animal functions hold under theirs 
 all the nutritive and reproductive ones, but these latter, in 
 their turn, keep the former in a similar state; the organs of 
 animal functions having to be nourished, in order to fulfil 
 their own, and these latter inducing the exercise of the organs 
 of the vegetative functions. So that, in animals whose orga- 
 nization is very much developed, life seems essentially to re- 
 sult from the reciprocal action of the central organ of the ve- 
 getative functions, and from the principal organ of the animal 
 functions, from the circulation and the nervons action, or in 
 other words, from the action of the blood on the nervous sys- 
 tem, and from the nervous system on the organs which propel 
 the blood. The other phenomena maintain these two princi- 
 pal actions, which may be considered as the two essentially 
 vital functions of animals. 
 
 16. To all these characters, the first very general and 
 common, and the second much less so, we must add the disor- 
 ders of the organization, and the phenomena of life, i. e. dis- 
 eases much more frequent in animals than in vegetables; and 
 the reason of this may be easily found in the complication of 
 their organization, in the concatenation of all the parts with 
 each other; and in the operation of central and predominating 
 organs, the action of which can not be disturbed without the 
 whole economy suffering by it. Hence the study of the causes 
 and external bodies which influence the animal organization 
 
 in a hurtful or beneficial manner, and the art of preserving or 
 6 
 
32 INTRODUCTION. 
 
 restoring health by the well directed employment of external 
 agents, or the science of medicine. 
 
 Such are the most general characteristics of animals; but 
 these beings present in their organs and functions a multitude 
 of varieties or of degrees of complication, that it is important 
 to examine. 
 
 17. The external form, or configuration, which may 
 give an idea of the structure, of which it is, in a manner, 
 the outline, presents the following varieties. Some animals 
 are punctiform or globular, as the monads; others are fili- 
 form as the vibrio; some are flat, resembling a small mem- 
 brane, such are the cyclida; finally, others belonging, like 
 the preceding ones to the class of infusoria, have no deter- 
 mined form, their configuration changing at every moment in 
 the most singular manner, these are the protei. These ele- 
 mentary forms, which pertain to all the animals that are the 
 simplest in their composition, are to be found in some indi- 
 viduals of a nobler order, and in certain parts of all others. 
 The same is the case with the stellated or radiated form which 
 belongs to a certain number of classes of animals, and that 
 we meet with in various parts of those animals which have a 
 very different external configuration. 
 
 The radiated form begins to be observed in the order 
 rotiferce, and other polypi; in the acalepha and echinoder- 
 rnata, the radiated form is not confined to their exterior, 
 which resembles a radiated flower, or to a star, but all the 
 parts are arranged around an axis, and on a greater or small- 
 er number of radii. In some other animals the axis being 
 longer, the radiated form becomes cylindrical. The cylindri- 
 cal echinodermata, intestinal worms and annelides establish 
 this passage from the radiated form, of which they still pre- 
 serve some slight marks, to the symmetrical form and articu- 
 lar arrangement which they likewise possess; and the tunicata 
 the transition from the radiated to the symmetrical form with- 
 out articulation. 
 
 The symmetrical form is to be observed, with some few ex- 
 ceptions, in all other animals. In those which have this con- 
 figuration, the body is divided into two lateral parts, or into 
 
OP ANIMALS. 33 
 
 two similar sides by a median line; but it is subdivided into 
 two others very different. In the mollusca the body is not 
 divided into segments, and there are no articulated feet, for 
 they are inarticulate. The other symmetrical animals, on the 
 contrary, are articulate, i. e. their body is divided into seg- 
 ments, moveable upon each other, and their limbs, when they 
 have any, are divided into several parts by articulations. We 
 already discover the articular arrangement in the cirrhipoda, 
 which properly belong to themollusca; the rudiments of it are 
 also perceived in iheci/lindricalechinodermata^nd in worms, 
 but this kind of form more particularly belongs to the annelides, 
 insecta, Crustacea, and arachnides, which for this reason are 
 called articulated animals, and to all the vertebrated animals. 
 Thus we may in conclusion refer the animal forms to the fol- 
 lowing: the symmetrical or binary form, with or without ar- 
 ticulations, the radiated form, and the simple forms of a glo- 
 bule, of a filament, &c. &c. 
 
 18. The external configuration of animals presents also 
 other differences. The body is divided into a trunk, a central 
 part, which contains the organs essential to life, or in other 
 words, the viscera, and into appendages, parts generally des- 
 tined for motion and sensation. The trunk is divided into the 
 trunk proper, or the middle part, and into the extremities, 
 the head and tail; the trunk itself is sometimes subdivided 
 into abdomen and thorax. The head is the part which 
 contains, besides the mouth, the principal nervous expansion, 
 or the brain, and the organs of the special senses. The tho- 
 rax, in the articulated animals, is the part of the trunk to 
 which the limbs are attached; in the vertebrata it is that which 
 contains the heart and lungs. The abdomen always contains 
 the principal organs of digestion and of generation. These 
 various parts of the trunk, which do not all constantly exist, 
 present diverse varieties. 
 
 In the radiated animals, in the acephalous mollusca, and 
 in the intestina and annelides, the trunk is reduced to its mid- 
 dle part, consists of a single cavity, which contains all the or- 
 gans. In the cephalous mollusca there is a distinct head; 
 the same is the case with the insecta, Crustacea, and arach- 
 
34 INTRODUCTION. 
 
 j which have besides a thorax, sometimes distinct from 
 the head and abdomen, and at others confounded with one or 
 both parts of the trunk. In the vertebrated animals the head 
 is always distinct, but the thorax is sometimes confounded 
 with the abdomen. The appendages present also different va- 
 rieties; in the infusoria there are small ones called cilias. 
 The radiated animals have the mouth surrounded with appen- 
 dages called tentacula, which are destined for motion and sen- 
 sation. The same is observed in some mollusca, which have 
 sensitive tentacula, and other fleshy productions, called arms 
 or feet, for the purpose of locomotion. The crustaceous ani- 
 mals and insects have antennae, articulated filaments, of very 
 diversified shapes affixed to the head, and which seem to be 
 organs of sensation. The same may be said of their palpi, 
 that are found also in the arachnida. The lateral appendages 
 are double, essentially intended for motion, and are called 
 limbs when they are articulated, the rudiments of them may 
 be observed in the cirrhopoda and in the setigerous an- 
 nelides; they are found in great number in the myriapoda; 
 they are also found in a considerable, but variable number, in 
 the Crustacea; there are eight in the arachnides, and six in the 
 true insecta, which possess, for the most part, either four or 
 two wings. In the vertebrata, there are never more than four 
 limbs. 
 
 19. The organs of nutrition present a very great diver- 
 sity. In the most simple animals, the infusoria, this function 
 consists solely in an external absorption or imbibition, the ma- 
 terials of which penetrates every part of the body of the ani- 
 mal, and is immediately assimilated and afterwards excreted ; 
 this simplicity of organization is to be found in some intes- 
 tinal worms, and in some of the acalepha. 
 
 In animals, a degree higher in the scale, we find an intesti- 
 nal cavity excavated in the substance of the body, and from 
 this moment absorption is performed by both surfaces, and 
 especially by the internal one. This simple cavity is observ- 
 ed in some polypi. At a still higher degree, this cavity con- 
 sists of a membranous sac, distinct from the mass of the body, 
 formed by a membrane or internal skin, continuous and analo- 
 
OF ANIMALS. 35 
 
 gous to the external one. The animals which present the 
 first rudiments of the arrangement, are also the polypi and 
 acalepha and some intestinal worms. In other animals of the 
 same class, the gastric cavity has prolongations extending into 
 the mass of the body, in order to provide it with nourishment. 
 In some acalepha and intestinal worms, the stomach is want- 
 ing, and there are only ramified prolongations opening on the 
 external surface. In all these first appearances of an intestinal 
 cavity, that cavity is confined to a mere elongated sac, having 
 one single opening. Several of the echinodermata, and in- 
 testinal worms have a distinct intestinal canal, a mouth and an 
 anus, an arrangement which is to he observed in all the higher 
 classes, in which this canal, more or less enlarged, or more or 
 less contracted, is extended through the body. The existence 
 of this canal is perceived at the same time with the cylindri- 
 cal and elongated form of the body. 
 
 The mouth presents several varieties, the principal of which 
 are those of a simple orifice, or an opening furnished with 
 muscles, and sometimes with hard parts, but intended for suc- 
 tion only; or an orifice surrounded with muscles, and furnish- 
 ed with hard parts to divide the aliment. 
 
 20. In many of the inferior animals, the nourishing fluid, 
 absorbed by the parietes of the intestines, which are either 
 simple or elongated and extended in the body by ramified ap- 
 pendages, is carried immediately by the areolar substance into 
 every part of it. This is the case with all the radiated ani- 
 mals, and with the immense class of insects. In fact, in no 
 insect are there any vessels, and the nourishing fluid must 
 pass by imbibition from the intestine into every part of the 
 body; there is only a dorsal vessel which appears to be the 
 rudiment of a heart, but there are no branches for circula- 
 tion. 
 
 In animals of a still higher class, the nourishing liquid, ab- 
 sorbed by the parietes of the intestines, circulates in close ves- 
 sels, the minute ramifications of which, only permit the nour- 
 ishing molecules to pass into the substance of the body. The 
 vessels which go from the centre of the circulation to all the 
 other parts are called arteries; those which bring back the li- 
 
36 INTRODUCTION. 
 
 quids from every part of the body to this same centre, are 
 named veins; at the point of reunion of both, is to be found in 
 many animals a fleshy organ, the heart, which aids by its con- 
 tractions the motion of the liquid, and which, like the vessels, 
 is more or less complicated. We find the first rudiments of 
 vessels in some intestinal worms, and the first rudiment of a 
 heart in insects. 
 
 In the annelides, the only invertebrated animals which have 
 red blood, there are arteries and veins for the circulation, but 
 there is simply a rudiment of a heart. In the arachnides tra- 
 cheariae, the organs of circulation are not any better marked 
 than in the insects; but in others, such as the pulmonariae, there 
 is a heart or great dorsal vessel and branches on each side. 
 
 The Crustacea present more distinctly a heart; in some it is 
 elongated into a large fibrous vessel which extends all along 
 the tail, giving branches on both sides, and which recall to 
 our minds the dorsal vessel of insects; but in other Crustacea, 
 there is a dorsal ventricle, a great abdominal vessel, and posi- 
 tive circulatory vessels. In the mollusca there is a heart more 
 or less complicated, a double system of arteries and veins; the 
 blood is white or bluish. Finally in the vertebrata, besides 
 the arteries, veins and heart, there is a particular system of 
 lymphatic and chyliferous vessels which convey the nourish- 
 ing fluid from the intestines into the veins. 
 
 The simplest heart is composed at least of a ventricle which 
 propels the blood into the arteries, and is often accompanied 
 with an auricle or venous sinus at their entrance into the heart; 
 it is called aortic when it sends the blood to the whole body, 
 and pulmonary when it sends it to the respiratory organs; it 
 is double when there are two ventricles, which, however, may 
 be separated or united. The heart is simple without auricle 
 and pulmonary, in all the articulated animals which are pro- 
 vided with one. The same is the case in fishes, with the ex- 
 ception of there being an auricle. The heart is simple but 
 aortic in most mollusca; it is triple in the cephalopodous mol- 
 lusca, in which there are two pulmonary ventricles and one 
 aortic, separated and without auricles. In all reptiles there is 
 one ventricle only, more or less divided by a partition, and 
 
OP ANIMALS. 37 
 
 which sends the blood into one single trunk, both aortic and 
 pulmonary; the greater number have two auricles, the batra- 
 chia have only one. Finally the heart is double in birds and 
 the mammalia, they have two auricles and two ventricles in 
 contact, one aortic and the other pulmonary. 
 
 21. In order that the nutritive fluid may be fitted for its 
 function, it must be submitted to the action of the atmosphere 
 in which the animal lives. In those which have no circula- 
 tion the water acts on the surface of the body; such seems to 
 be the case with the infusoria, polypi, and acalepha: the in- 
 testinal worms also have not the least appearance of respiratory 
 organs. In another degree of organization, air or water pene- 
 trates into every part of the body by elastic canals called tra- 
 cheae, and which are lined by a prolongation of the skin. The 
 echinodermata have aquiferous tracheae; in insects there are two 
 longitudinal tracheae extending throughout the body, having 
 at intervals common centres from which arise many branches, 
 and which correspond to stigmata, or external openings for 
 the entrance of air. In animals that have acirculation, part 
 of the vessels carries the blood into an organ in which they 
 are subdivided over an extensive surface of the external or in- 
 ternal skin. This surface is salient and is called branchiae when 
 the ambient element is water, and lungs, and hollow, when that 
 element is air. In order to carry on the branchial or pulmo- 
 nary respiration, there are generally organs for motion, to put 
 the ambient fluid in contact with the organ. In the arachnides, 
 we find the transition of disseminated respiration, which yet 
 exists in the tracheariae, to the local respiration, which occurs 
 in pulmonary sacs. In the Crustacea generally, the respirato- 
 ry organs are projecting branchiae variously configured. The 
 same is the case with most of the annelides. In the mollusca, 
 generally, we find a very great variety in the organs of respi- 
 ration. Some breathe the air itself, and have a pulmonary 
 cavity; these are the gasteropodia with lungs; others have pro- 
 jecting branchiae variously configured; others again have their 
 branchiae in a cavity into which the water is drawn. In fishes, 
 respiration is branchial; but it is pulmonary in the other ver- 
 tebrated animals. 
 
38 INTRODUCTION. 
 
 Respiration is partial, and circulation simple in reptiles, in 
 which there is only one ventricle and one aorta, of which the 
 pulmonary artery is a branch. In all other animals which 
 have a local respiration and a circulation, this latter is double, 
 and respiration complete; i. e. at every circuit of the blood, 
 the whole liquid passes through the respiratory organs. In 
 the articulated animals and mollusca, the circle is simple; in 
 the former the blood goes from the heart to the whole body, 
 and passes entirely through the branchiae; the same is the 
 case in fishes; in the mollusca, it goes from the heart to the 
 branchiae, passing first through the whole body. In birds and 
 the mammalia, the two hearts being joined, the circle is dou- 
 ble, or rather, the circuit is crossed, and ma} r be represented 
 by the figure 8, at the centre of which is the heart. 
 
 22. The nutritive fluid must not only be submitted to 
 the action of the atmosphere, but must also be freed by the 
 secretions, from superfluous matters. In animals which have 
 an internal cavity, and consequently two surfaces, these two 
 surfaces, in all their extent, serve for the purpose of excretion 
 as well as of absorption. The internal and external skin pre- 
 sent also small cavities or particular depressions from which 
 the liquid issues. Finally, even in the animals in which there 
 is no circulation, if some particular liquid is to be produced, 
 the cavities or depressions either internal or external, of the 
 skin, are prolonged and ramified into the body in the form of 
 vessels or excretory canals, and take up from the nutritive 
 fluid, the elements proper for the composition of this liquid. 
 In the same manner, in the animals which have a circulation, 
 the vessels sometimes spread simply over large surfaces, and 
 permit the secreted fluid to escape by perspiration; at others it 
 is from the bottom of small cavities or follicles formed either in 
 the internal or external skin that the liquid oozes; in other parts, 
 the arteries, at the point where the arteries change into veins, 
 communicate with ramified excretory canals which are always 
 formed by the internal or external skin; and from the union 
 and combination of these canals with the blood vessels, result 
 the glands. These last organs of secretion are peculiar to those 
 animals which have a heart The liver, for instance, which is 
 
OF ANIMALS. 39 
 
 the most general of these organs, does not yet exist in the 
 arachnidestracheariae, but under the form of a separated vessel 
 as in insects; on the contrary, in the arachnides pulmonariae, 
 and in the Crustacea, we still find the liver divided into dis- 
 tinct lobes, or as in some, in the form of a hunch of grapes. 
 The mollusca have a very considerable liver; most of them 
 have salivary glands, but neither pancreas nor kidneys. Se- 
 veral have secretions peculiar to themselves. All the verte- 
 brated animals have glands, and in addition to what the others 
 possess, they have kidneys, organs which have many points 
 of relation with those of generation. Among the liquids 
 which result from the various secretions, some have their ap- 
 propriate use in the exercise of the functions, as saliva, bile, 
 &c.; others, such especially as the urine are rejected as su- 
 perfluous and hurtful. 
 
 Thus the organs of the nutritive functions in their great di- 
 versity, consist in a permeable absorbing substance, which as- 
 similates and excretes; in one or two surfaces, the skin and 
 intestines, which foreign substances have to traverse from 
 without inwardly, or from within outwardly by absorption, 
 or by excretion; in vessels which establish communications 
 between the surfaces of the body and all the parts of its sub- 
 stance, and vice versa; in respiratory organs, which are a por- 
 tion of the surfaces, where the liquid comes in contact with 
 the atmosphere, and in secretory organs, another part of the 
 surfaces, where a portion of the liquid is rejected. 
 
 23. Generation, or the production of a new being simi- 
 lar to the one to which it owes its origin, is the second func- 
 tion in point of importance, common to all organized and liv- 
 ing bodies, and presents also in animals a great variety in its 
 organs and phenomena. This function in its simplest state, 
 has no particular organ ; but the whole body being very sim- 
 ple and homogeneous, divides itself in several fragments, 
 each of which preserve the properties of the whole mass; 
 this is called the fissiparous generation, it belongs especially 
 to the infusorii, and exists accidentally in others. In some 
 animals of the same class, we observe in the substance of the 
 body globules or corpuscular substances which appear capa- 
 
40 INTRODUCTION. 
 
 ble of reproduction, this is the subgemmiparous generation or 
 the first indication of a production of buds. In a higher de- 
 gree of animals, generation is truly gemmiparous, a bud grows 
 on the external surface of the body, and afterwards drops off 
 to form a new being distinct from its parent, or it continues 
 to remain united, and forms a branch of it. This kind of ge- 
 neration belongs to the polypi.- The internal gemmiparous or 
 suboviparous generation is also to be met with in theirs. Its 
 organ consists in cavities prolonged in the mass of the bod}'', 
 and in the interior of which grow buds or ovula, which sepa- 
 rate spontaneously and issue by traversing a canal which 
 opens on the external surface. This mode of generation 
 is also that of the acalepha, echinodermata, and perhaps in the 
 cestoid intestinal worms. The acephala and some mollusca 
 gasteropoda differ only from them because they have a true 
 ovary. In all those beings, there are properly speaking no 
 sexual organs. 
 
 24. In all beings of a higher organization, there are 
 genital organs for both sexes, the concurrence of which is ne- 
 cessary to animate the germ. The female organs consist in a 
 mass of germs or an ovary, and in a canal through which issue 
 the germs when detached; this is called the oviduct ; and in 
 several species, in a cavity in which they remain for a longer 
 or shorter time, into which they ingraft themselves, and in 
 which they acquire a certain growth before they are born, this 
 is the uterus, and the orifice through which they come into 
 the world, the vulva. The male organs are composed of glands 
 called the testicles, which secrete the sperm, a fecundating li- 
 quor, and when this is to be introduced into the body of the 
 female, the male is provided with a penis. In this kind of 
 organization the concurrence of the two sorts of organs is ne- 
 cessary to bring about generation. We find the first rudi- 
 ments of this organization in some intestinal worms; but these 
 animals being not provided with a circulation, their ovary and 
 testicles simply consist in free or floating secretory vessels. 
 The genital organs are also of two kinds in many of the mol- 
 lusca, in the annelides and other articulated animals, and in 
 the vertebrata. The ovaries and testicles are glandular masses 
 
OP ANIMALS. 41 
 
 only in those animals which have a circulation. Among these, 
 some are hermaphrodite, or are provided with both male and 
 female organs; but this hermaphrodite state is incomplete, or 
 rather insufficient; for in order to engender they require a 
 reciprocal copulation with another similar individual: such 
 is the case with some annelides and mollusca. In a more ele- 
 vated order of beings, the genital organs are separated and 
 borne by different individuals, and this constitutes the sexes. 
 This occurs in some intestinal worms, in many mollusca, in- 
 secta, Crustacea, arachnida, and in all the vertebrate animals. 
 
 25. In sexual generation, the germ is enclosed with nu- 
 tritive substances in a membranous or more solid, and even 
 calcarious envelope ; then it is called an egg. Sometimes the 
 egg contains nutritive materials in a sufficient quantity to de- 
 velope completely the embryo, and receives through its cover- 
 ings the influence of atmospheric air only, and scarcely that of 
 humidity ; the animal is then said to be oviparous, either if the 
 egg be laid entire, and the development of the embryo occur 
 after being laid, or if the development precede the laying of 
 the egg, and the egg break at the moment of its birth. In 
 oviparous generation, the germ is only separated, generally, 
 after fecundation; nevertheless, in some instances the germ is 
 separated before, and the egg is fecundated during or even 
 after the laying. The egg does not always contain sufficient 
 materials for the development of the embryo; in that case it 
 ingrafts itself by its surface in the uterus, and absorbs therein 
 nutritive substances; the young one is born living with the 
 remains of its membranous egg, but in a state of weakness 
 which requires to be nourished with an animal fluid that the 
 mother secretes the milk. The mammalia are alone in this 
 situation. Some young animals, on quitting the egg bear no 
 resemblance to their parent; they experience before reaching 
 their form a change which is called metamorphosis: such are 
 the larva of insects, and the tadpole of the batrachia; the 
 others, on the contrary, are born similar to their parents, or 
 at least there are only some slight differences of proportion, 
 which in time disappear. 
 
 26. Nutrition and generation are not the only two modes 
 
42 INTRODUCTION. 
 
 of the formation or production of animals; they possess also, 
 although in a less degree or less general manner than vegeta- 
 bles, the faculty of reproducing by a kind of vegetation, parts 
 which have been cut off or destroyed ; but the faculty is not 
 even in the same degree in every animal: The simplest ani- 
 mals in organization possess it in the greatest perfection. The 
 polypi, and especially the hydra, always reproduce those por- 
 tions which have been cut off, so that, individuals are multi- 
 plied by the simpleact of division of parts. The power of repro- 
 duction of the actinia is no less extensive; they reproduce 
 parts which have been taken away, and are multiplied by the 
 division. The asterias have also a great power of reproduc- 
 tion ; they again produce the rays which are destroyed; even 
 when a single ray, provided it be entire, can reproduce the 
 others. The faculty possessed by the toenia of reproducing 
 the posterior rings of their body is well known. Among the 
 annulosa, the nereides has also a very great power of repro- 
 duction. Experiments have been performed on the lobster, 
 which went to prove the power possessed by this animal of 
 shooting out a new foot whenever it has been injured by acci- 
 dent. It seems that the arachnides also have the faculty of re- 
 generating legs which they have lost. The aquatic salaman- 
 ders have also an astonishing power of reproduction; they 
 shoot out several times in succession the very same limb when 
 cut, and that too, with its bones, muscles, vessels, &c. The 
 limbs and tails of the tadpole of the frog is also regenerated 
 very much like those of salamanders. The tail of the sauria, 
 when torn off, grows again, although sometimes a little differ- 
 ent from the first one. In warm blooded animals the power 
 of reproducing parts which had been removed by excision, 
 is almost confined to epidermic or horny parts. As to the 
 other parts, this power does not extend beyond the healing of 
 wounds, and the production of a cicatrice analogous to the skin, 
 when this latter is cut off or destroyed. 
 
 The organs and functions belonging to animals, present, like 
 the preceding, many degrees of complication or varieties in 
 the beings which compose the animal kingdom. 
 
 27. In the simplest animals the body being, or appearing 
 
 
OF ANIMALS. 43 
 
 to be homogeneous, we perceive no particular organ for mo- 
 tion, and nevertheless these infusory animalcule move about 
 with great rapidity. There are other animals a little more com- 
 plicated, which are yet unprovided with any kind of distinct 
 muscular organ: such as the rotiferae, which have a particular 
 rotatory organ, or like the polypi, which have around their 
 mouth tentacula, the movement of which agitates the water, 
 and with which they attract and seize nutritious substances, 
 and some of which possess, besides, movements performed by 
 the whole body. The proper organ of visible motion, the 
 muscular fibre, exists in the acalepha, and in the echinoder- 
 mata, the muscular system of which is supported by a well or- 
 ganized skin, and in all the more elevated animals in which 
 the apparent movements either general or partial, are pro- 
 duced by the action of these organs. The muscular fibres, in 
 all animals, which have any*, supply the external and internal 
 skin: they also form the heart of such animals as possess one. 
 Among animals, some have the skin as soft as jhe other parts 
 of the body; in a great many, it contains within its thickness 
 indurations, either calcarious, or horny, which shield the ani- 
 mal from external injuries, and which being moveable on each 
 other, transmit to the parts they support, the motion that they 
 have previously received from the muscles. In the verte- 
 brate animals, this latter office is fulfilled by moveable, articu- 
 lated, internal bones, and which for this reason are provided 
 with a great mass of muscles which is either wanting in the 
 invertebrata, or is attached on their cataphracted or indurated 
 skin. 
 
 28. In the simplest animals, the organs of the sensations 
 have no distinct existence. The whole body seems to receive 
 impressions as it executes movements. In those which have 
 an external and internal skin different from the remaining 
 parts of the body, and all from the polypi upwards, have this 
 arrangement, the skin, besides the function of absorbing nu- 
 tritious substances, receives the impression of external bodies. 
 In those animals which have a very soft skin and but little dif- 
 ferent from the other parts, it is every way equally sensitive. 
 But the part of the skin which is moistened in various animals 
 
44 INTRODUCTION. 
 
 with mucus or with a sebaceous matter, is in many, provided 
 with an epidemics, hairs, horny scales, or a calcareous crust, 
 and becomes also an organ of defence and support. In this 
 case, some parts are not covered with these envelopes, are 
 very moveabie,and constitute particular organs of touch; such 
 are the tentacula of sea-urchins, those of some fish, those 
 of mollusca; the antennae of insects and Crustacea, &c. 
 
 The organ of taste is not to be met with, distinctly, in all 
 animals which digest, and )~et it seems requisite that this sen- 
 sation should exist in all. In the radiated animals, nothing is 
 to be perceived, at the entrance of the alimentary canal, which 
 seems to be that organ. The same is the case with respect to 
 the mollusca and articulated animals. In some insects, how- 
 ever, this faculty is supposed to exist in the extremity of the 
 proboscis or palpi; finally, all the vertebrata are far from hav- 
 ing a tongue organized in a manner to enable them to taste. 
 
 The organ of smell seems to be wanting in a great number 
 of animals; insects, however, Crustacea, and arachnides are sen- 
 sible to odours, but the precise seat of their sensation is en- 
 tirely unknown. The same may be said with respect to the 
 mollusca. Even in the vertebrata the nasal fossae do not tra- 
 verse the face in all the classes. 
 
 The organ of hearing or the ear is not found in the lower 
 classes of animals, and sound seems to be only perceived as a 
 tactile impression. Among articulated animals the crab is the 
 only one in which we observe an ear, though they all hear 
 very well. The ear in the crab consist of a bag filled with a 
 gelatinous lymph, which receives a separate nerve. In the 
 same manner, the mollusca and cephalopoda have this organ, 
 which exists in the vertebrata, and which presents a great va- 
 riety. 
 
 Light has also an action on the skin of all animals, and on 
 every part exposed to its influence; but the faculty of sight is 
 possessed only by those who have its organ, the eye. The 
 radiated animals have no eyes. A portion of the annelides are 
 deprived of it; in the others we only meet with the rudiments; 
 it is a mere black spot. The articulata with feet, viz: the crus- 
 tacea, arachnides and insecta, have all eyes which may be of two 
 
OP ANIMALS. 45 
 
 kinds, more or less numerous, and always symmetrical; viz. 
 simple eyes, the cornea of which present only one facet, the 
 iris only one opening, and the optic nerve a single filament, 
 and compound eyes, or with man}* facets with as many pupils 
 and with as many filaments of the optic nerves. Sometimes 
 the eyes are pediculated or placed on articulated appendages. 
 The acephalous mollusca are deprived of eyes; most gastero- 
 poda have them, but small and rudimental, placed either on 
 the head or the posterior tentacula. The cephalopoda have 
 two large eyes covered with a transparent skin.' In the ver- 
 tebrated animals, the eyes are wanting in a very small num- 
 ber of species. 
 
 29. The nervous system is unknown and seems not to 
 exist in the infusorii. The first rudiments of it are to be ob- 
 served in the radiated animals. The Hydra, among polypi, 
 possess microscopic globules the nature of which is uncer- 
 tain. But in the sea-star and in the Holothuria there are gan- 
 glia arranged in a circular form around the mouth, communi- 
 cating with each other by soft filaments, distributing others in 
 a radiating manner to the different parts of the body, where 
 some are conveyed to the external, and others to the internal 
 skin. In some intestinal worms we observe a nervous ring 
 around the mouth, whence arise two cords which extend the 
 whole length of the body. In the articulated animals the ner- 
 vous system presents a tolerably general character. There is 
 a little enlargement placed on the sesopbagus called brain, fur- 
 nishing nerves to the parts which are connected with the head. 
 Two cords, which encircle the aesophagus like a necklace, ex- 
 tend under the intestinal canal, and unite at intervals, forming 
 as many double ganglia or knots as there are rings in the body; 
 thence arise the nervas of the trunk and those of the extremi- 
 ties when any exist. The arrangement is nearly the same in 
 the cirrhipoda. In the mollusca there is a greater variety than 
 among the articulated animals. These means of communica- 
 tion, however, are ganglia united by cords, and conveying 
 filaments to the different external and internal parts. In the 
 acephala there is above the mouth a principal ganglion, im- 
 properly called brain, and another at the opposite extremity 
 
46 INTRODUCTION. 
 
 of the body; behincl the intestines, txvo nervous branches es- 
 tablish a communication with the various ganglia, and em- 
 brace in their lateral extension, the viscera; other filaments 
 are distributed to the different parts of the body. In the mol- 
 lusca provided with a head, there is a nervous enlargement or 
 a principal medullary mass called brain, situated across and 
 over the aesophagus which it envelops with a nervous ring, 
 which terminates underneath in another but larger ganglion: 
 these enlargements send filaments to the head and to the va- 
 rious parts of the viscera. In some of them, there are besides 
 other small ganglia. The cephalopoda alone have their brain 
 enveloped in a kind of cartilaginous cranium. 
 
 The general character of the nervous system of the inver- 
 tebrate animals, particularly consists in the dissemination of 
 the nervous centres, and in the circumstance that the parts 
 either external or internal, or those which belong to the vege- 
 tative functions, or those which belong to the animal func- 
 tions, receive their nervous filaments from the same centres. 
 We shall see, on the contrary, that in the vertebrata the ner- 
 vous system is differently disposed, and in a manner which 
 entirely distinguish them from other animals. 
 
 30. Nervous action or innervation, presents in animals 
 varieties corresponding to those which are observed in the 
 disposition of the nervous organs. In 1 those animals which 
 have no nervous system, and in those in which this system has 
 no centre, (the radiated animals,) impressions are immediate- 
 ly followed by movements; a part or an animal is called irri- 
 table whose movements are produced by impressions. In the 
 radiated animals the mouth or the orifice through which they 
 take their nourishment is the most irritable part; it is also at 
 this place the nervous system begins to appear in animals of 
 this class provided with it. All other animals have also irri- 
 table parts. In the mollusca and in the insecta in which the 
 divers ganglia of the nervous system are connected with each 
 other by nervous cords, in such a manner as to form a centre, 
 and in which there are organs of a special sensation, the im- 
 pressions received by the senses produce sensations, and the 
 movements are caused by volition. The internal movements, 
 
OF ANIMALS. 47 
 
 however, are produced by irritation, but irritability in these 
 animals is dependent upon the nervous system. We also ob- 
 serve in them, and especially in insects, a faculty called in- 
 stinct^ and which, like an irresistible impulse, causes them to 
 produce, without being taught and without imitation, very 
 complicated actions, that are necessary to their preservation 
 and to that of their species. The vertebrated animals besides 
 irritability, sensibility, voluntary movements and instinct, 
 have cerebral functions which, to a certain degree, resembles 
 intellect. 
 
 31. The varieties or the degrees of complications which 
 exist in each apparatus or function, are combined in various 
 modes, which constitutes the varieties of the general orga- 
 nization. The combination or the coexistence of the vari- 
 ous apparatuses of organs is determined; a certain state of 
 the nutritive or genital organs requiring, for the support of 
 life, some corresponding state of the organs of motions, of 
 sensibility, &c. According to a well defined distinction of or- 
 ganization, animals are divided into vertebrate and inverte- 
 brate. Man belongs to the former of these divisions. 
 
 32. Although the invertebrata differ greatly from man, 
 their study is nevertheless of great utility to the anatomist and 
 physiologist ; we observe in them organization and life in 
 their greatest simplicity? and under a multitude of varieties. 
 They differ so much with each other, that they have no com- 
 mon and positive character. According to their organization, 
 they are divided into three great sections which differ from 
 each other as much as they are unlike the vertebra: these are 
 the radiated animals, the mollusca, and the articulata; and we 
 find even besides these three divisions, a class of very ques- 
 tionable beings that zoologists describe under the name of in- 
 fusorii, and which botanists claim as belonging to the con- 
 ferva. 
 
 33. These dubious and microscopical animals, have a very 
 simple organization, different forms, and sometimes changea- 
 ble; they are homogeneous, transparentand diffluent; they have 
 no cavity, no distinct organ; they move, however, in the water 
 8 
 
48 INTKODUCTION. 
 
 which contains them, are nourished by imbibition, and mul- 
 tiply by spontaneous division. 
 
 34. The radiated animals constitute a particular type, 
 the essential character of which consists in the form, which 
 is, a centre around which the other parts are arranged like the 
 spokes of a wheel. Their structure, rather simple, presents 
 several varieties from the simplest among them, the hydra or 
 polypus with arms, to the asterias or sea-star. They all in- 
 habit the water. 
 
 35. The polypi form an extremely numerous class of ra- 
 diated animals. They are generally elongated, having one 
 single orifice or mouth furnished with radiating appendages; 
 they have an alimentary cavity, digest very quickly, and ab- 
 sorb by imbibition, produce buds which sometimes remain ad- 
 herent and form complicated phytoid animals, and at others 
 separate. The external and internal surfaces are alike; the 
 intermediate substances are homogeneous and gelatinous; no 
 peculiar organ is observable, except microscopical globules, 
 and they possess in a high degree the power of reproduc- 
 tion, for when divided, each part becomes an individual. 
 Light, noise, and other exterior causes, produce on them im- 
 pressions followed by motions. Some are fixed to the ground, 
 others are free. The simplest of all are those which are neck- 
 ed, as the hydra, &c.; they have a simple alimentary sac, 
 and multiply by external buds. Others again which are unit- 
 ed, excrete from their external surface a horny or calcareous 
 substance called polypier.* Finally, in others, which are 
 complicated animals, the common body envelops a secreted 
 substance, the consistence of which varies from that of jelly 
 to that of stone. 
 
 36. The acephalous animals or sea-nettles (medusae,) 
 have a still more circular or radiated form ; they are compared 
 
 * Under this appellation are grouped the calcareous substances 8tc. known 
 under the name of madrepore, coral, &c. which are the excretions of the po- 
 lypi here alluded to and serving them for habitation. These calcareous 
 excretions are comprehended by the French under the general designation of 
 polypier, for which there is no adequate term in the English language. 
 
 TRASS. 
 
OP ANIMALS. 49 
 
 to rosaceous or radiated flowers. Their structure is various, 
 for some are as simple as the most simple polypus, and others 
 are much more complicated ; the mouth is central, furnished 
 with tentacula, leading into a stomach, often ramified, but 
 which has no other issue. There are for the purposes of ge- 
 neration, a number of oviform internal Tbuds in particular 
 cavities. 
 
 37. The echinodermata are the radiated animals, the or- 
 ganization of which is the most complicate: the class contains 
 the stellated, the spheroidal and the cylindric forms. They 
 have an internal cavity in which distinct viscera float; their 
 intestine has vascular like prolongations ramified through the 
 body. Some have a distinct anus; the organs of respiration 
 are ramified aquiferous canals ; the organs of generation are 
 oviform masses of internal buds, which terminate either at 
 the mouth or at the anus ; they have muscles, and in the 
 greater number there are particular organs of locomotion, 
 consisting in numerous tentacula terminating in the form of a 
 cupping glass, called feet ; the skin is well organized, and 
 often solid ; some have even nervous filaments. 
 
 38. The articulated animals constitute a division of the 
 animal kingdom in which the body is symmetrical, divided 
 externally in a certain number of rings or moveable segments, 
 and formed by the skin, more or less tough and sometimes 
 hard, except between the intervals of the rings in which it al- 
 ways retains its softness and flexibility. Their muscles are 
 connected with the, inside of the skin; their nerves are cords 
 with enlargements at intervals, situated beneath the intestinal 
 canal. This type however comprehends extremely varied or- 
 ganizations. Some are vermiform, without head and articu- 
 lated feet, and can only creep: these are the worms and the 
 annelides. 
 
 39. The intestinal worms, or the helminthia, which bear 
 some general resemblance to the radiata, have the body com- 
 monly elongated, cylindrical or depressed, naked and soft; they 
 have no organ either of respiration or circulation. Their genera- 
 tion is internal, gemmiparous, and sexual, oviparous; they inha- 
 bit the bodies of other animals, and present otherwise very dif- 
 
50 INTRODUCTION. 
 
 ferent degrees of organization. The simplest of all, the cestoid 
 species, the ligula, resemble a long striated ribbon, marked with 
 a longitudinal line. No external organ, not even suckers, are 
 perceived on them, and nothing internally, but oviform corpus- 
 cules in the mass of the body. Others again, whose forms are 
 much varied, such as the trematodes and tenioides, have only on 
 the exterior a greater or smaller number of suckers, sometimes 
 ramified in the body, which present other canals, either gem- 
 miferous or ovariferous. The acanthocephali echinorhynchi 
 have a proboscis armed with hooks, furnished with muscles; 
 they have two little coeca, and also either distinct oviducts, or 
 spermatic bladders, according to the sexes, which are sepa- 
 rated. The nematoides, as the ascarides, &c.; are still more 
 complexly organized; they have a mouth and anus, and an in- 
 testinal canal floating in a distinct abdominal cavity; their ex- 
 ternal skin is furnished with muscular fibres, in general, trans- 
 versely striated. They have distinct genital organs consisting 
 of long canals. The sexes are separated. They have a ner- 
 vous ring which surrounds the mouth, and two long cords, one 
 dorsal, the other ventral; they have also two spongy, lateral 
 vessels. 
 
 40. The annelides or red blooded worms are vermiform 
 animals, whose elongated bodies are divided into numerous 
 rings, the first of which, called the head, differs but little from 
 the rest; the mouth is either a mere tube or jaws. There is an 
 intestine longer or shorter, which traverses the body; there is a 
 double system of arteries and veins, without any well defined 
 heart; the blood is red, the respiration branchial. They are 
 hermaphrodites, with a mutual copulation, they have muscles, 
 and the greater number, stiff bristles serving for feet; the head is 
 furnished with tentacula, and some of them with black points 
 that are considered as eyes; the nervous system consists in a 
 knotty cord. 
 
 41. The other articulated animals, are all provided with 
 a head, and have all eyes, either simple or compound; their 
 very complex mouths, greatly resemble one another, and pre- 
 sent two modifications: in the first, for the purpose of grind- 
 ing, there are several pairs of lateral jaws, the anterior of which 
 
OP ANIMALS. 51 
 
 are called mandibles and often palpi, articulated filaments, 
 which appear to serve in recognizing their food: in the second, 
 there is a proboscis for suction. The organs of digestion are 
 complicated and various. They enjoy the sense of smell, but 
 its seat is not well determined. They have all an abdomen, 
 and a thorax which supports six articulated feet, at least. Their 
 skin is encrusted and solid,each articulation of the feet is tubular 
 and contains the muscles of the succeeding one. All the ar- 
 ticulations <K the feet are by gynglymus; generation is sexual 
 and oviparous. This section contains three great classes, that 
 of insects, the arachnides, and the Crustacea. 
 
 42. Insects, or the hexapoda, have the body composed of 
 segments or numerous rings, and divided into three principal 
 parts, six articulated feet, a distinct head furnished with eyes, 
 and two antennae, a thorax which supports the feet and wings, 
 when there are any, and an abdomen which contains the prin- 
 cipal viscera. The mouth is very complex, in the grinders, 
 there are lateral jaws, in the suckers there is a proboscis. The 
 intestinal canal more or less long, enlarged, contracted, &c,, 
 terminates by an anus. There is a vestige of a heart in a vessel 
 attached along the back, divided into segments by strangula- 
 tions, and which experiences alternate contractions. The fluid 
 it contains is white, and appears to penetrate it, like the rest 
 of the body, by imbibition. Respiration is effected by means 
 of ramified tracheae united in two principal trunks. The se- 
 cretory organs consist in long spongy vessels or canals, dou- 
 bling on themselves, running through the mass of the body, 
 and ending either in the intestine or elsewhere, according to 
 the uses of their products. The sexes are separated most fre- 
 quently, the genital organs terminate in the anus. These ani- 
 mals copulate but once in their life. The impregnated female 
 deposits her eggs in a suitable spot, and the eggs produce ver- 
 miform animals called larvae, which changes into a chrysalis, 
 a state of apparent death; and from which emerges the perfect 
 insect that soon propagates its species and dies. This consi- 
 derable change of external form, accompanied by others more 
 or less great in the structure, is called a metamorphosis; all in- 
 sects, the thysanouraand the parasiticaexcepted, which by their 
 
52 INTRODUCTION. 
 
 resemblance to mites, approximate to the arachnides undergo 
 it; some of them however do not suffer this change in all its 
 extent, and it is then called imperfect. The organs of motion 
 are the muscles and the skin, hardened by a horny substance 
 contained within its thickness; there are six articulated feet, 
 and generally four wings, some have only two, while a very 
 small number are apterous. Their motions are greatly varied, 
 and consist in the walk, running, jumping and flight. The or- 
 gans of the sensations are compound eyes, and in many simple 
 ones, generally three in number; antennae and palpi. They enjoy 
 both hearing and smell, but their organs are unknown. The 
 disposition of the nervous system is indicated in 28, and ter- 
 minates anteriorly by a little enlargement or brain, situated 
 on the oesophagus, and is distributed to the eyes and other 
 parts of the head. 
 
 43. The arachnides or octopoda, whose head, deprived 
 of antennae, confounds itself with the thorax, have eight feet 
 and no wings. The alimentary canal begins in the one by a 
 mouth with two lateral mandibles, in the other by a mouth 
 fitted for suction or by a proboscis. The greater number have 
 palpi, are subject to moults or a changing of skin, and not to a 
 metamorphosis. The sexes are separated, generation is ovi- 
 parous, and they have generally visible eyes, which vary in 
 regard to number and situation. 
 
 They present two degrees of organization; the first or sim- 
 plest is that of tracheal arteries, where there are no organs of 
 circulation more apparent than in insects; the organs of respi- 
 ration are distinct branching tracheas. The most complex is 
 that of the pulmonary or branchial arteries, (spiders, tarantula 
 and scorpions.) They have a simple muscular heart, dorsal, 
 elongated, cylindrical, branchial or pulmonary, whence are de- 
 rived the vessels for the respiratory organs, which are pulmo- 
 nary sacs, and thence distributed to the whole body. There 
 is also a liver composed of lobules or grains, collected in clus- 
 ters. The sexual organs are double in each sex. Some of them 
 copulate repeatedly and live several years; the scorpions are 
 ovoviviparous. 
 
 44. The myriapoda or centipedes form a little group of 
 animals, intermediate to the Crustacea which they resemble by 
 
OP ANIMALS. 53 
 
 their form, and to insects which they approach in structure, 
 still differing however from both. Their body is elongated, 
 and formed of a generally considerable number of rings, each 
 having one or two pairs of feet. The head is furnished with, 
 antennae and two eyes. Their jaws and mandibles are analo- 
 gous to those of the Crustacea. Their respiration is tracheal. 
 On quitting the egg, the young have six feet and seven or 
 eight rings, the other rings and feet which support them 
 being developed by age. 
 
 45. The crustacea are of all the articulata with articulated 
 feet, the most complex in their organization. The head and the 
 rest of the trunk are sometimes confounded, and at others 
 distinct, they have a tail more or less elongated, divided into 
 segments, and commonly four antennae. The greater part of 
 them have the mouth fitted for grinding and for that purpose 
 are furnished with several jaws, at least six, always lateral. 
 There are always at least fi-ve pairs of feet for motion, whose 
 forms vary according to the kind of movement to be performed. 
 The number of locomotive feet is in an inverse ratio to that of 
 the jaws: in fact the anterior feet approximate to the jaws, in 
 taking their form, and in filling a part of their functions, they 
 can even completely take their place. For respiration they 
 have pyramidal lamellated filamentous and tufted branchiae, 
 generally adhering to the base of some of the feet, or 
 which they even partly replace. Their circulation is double; 
 the blood that has been submitted to the respiratory action, is 
 poured into a great ventral, aortic vessel, which distributes 
 it to all the body, whence it returns by another great vessel or 
 even a true dorsal ventricle, which transmits it to the bran- 
 chiae. They possess a liver, more or less divided, sometimes 
 even into distinct canals, according to the state of the heart. 
 Generation is sexual and oviparous, without a true metamor- 
 phosis. The greater part carry their eggs with them, and 
 they all inhabit the water. They present otherwise a great 
 variety of organization. The jaws, the feet and the branchiae 
 are so nearly allied, that these appendages have all been con- 
 sidered as being of one kind, the first resulting from a trans- 
 formation of the last. The greater part of them have a shell 
 
54 INTRODUCTION. 
 
 more or less solid than the rest of the skin, which covers the 
 trunk, and in some even the head. In several orders, the sto- 
 mach, which is highly muscular, is provided with a cartilagi- 
 nous skeleton and with tubercles or teeth. The intestinal 
 canal is commonly short and straight. The position of the 
 genital organs varies; in some genera these organs are double. 
 The eyes offer much variety, arid in a few are wanting; in 
 others they are very nearly joined, and seemingly thrown into 
 one; some again have compound eyes, supported by amovea- 
 ble pedicle. Finally, in some of the Crustacea decapoda, there 
 are distinct organs for hearing. 
 
 46. The mollusca form a division of the invertebrata, in 
 which we generally find a symmetrical or binary form, but 
 no articulations. Their stomachs are simple or multiple, some- 
 times furnished with hard parts, and their intestines variously 
 prolonged. The greater part have salivary glands, all a vo- 
 lumnious liver, and many peculiar secretions. Their circula- 
 tion is double, and there is always at least one fleshy ventricle 
 which is aortic, and receives the blood from the organs of re- 
 spiration and sends it back through the arteries of the body. 
 In those that have more than one ventricle, they are not unit- 
 ed in one single mass, but form several distinct hearts. The 
 blood is bluish. The organs of respiration are sufficiently di- 
 versified to enable some to respire air and others water. Ge- 
 neration also in them presents all its varieties; some not hav- 
 ing the sexes and producing living young ones without copu- 
 lation, and others being hermaphrodites with a reciprocal 
 copulation, while in a third the sexes are separated. The eggs 
 of the latter are simply enveloped with a viscous matter, and 
 others again have shells more or less hard. These animals 
 are very prolific and very tenacious of life. Their muscles 
 are attached to the interior of a soft and elastic skin, and their 
 movements are produced by parts that have no solid levers. 
 They are highly irritable. Their naked skin is covered with 
 a mucous fluid that oozes from it. Almost the whole of them 
 have a development of the skin which covers up the body 
 like a mantle, variously diversified, however, as to figure. This 
 mantle sometimes remains soft, but most frequently it hap- 
 
OF ANIMALS. 55 
 
 pens that one or more plates, now and then horny, but oftener 
 calcarious, is formed in its thickness. This substance is ordi- 
 narily sufficiently large to enable the animal to cover itself 
 completely with it: this is what we call a shell. Many are 
 deprived of eyes, some have rudimental ones, and those of 
 others are highly developed. Their nervous system consists 
 in medullary masses dispersed throughout the body, the chief 
 of which is situated across the oesophagus, which it surrounds 
 with a nervous circle. They have but little instinct, and for 
 the most part inhabit the water. Besides this they present se- 
 veral differences of organization, some assume that of the ra- 
 diata, others that of the articulata, and a third by the complex 
 nature of their organs approximate to the vertebrata. 
 
 47. The acephala without shells or the tunicata have some 
 resemblance to the radiated animals. Some are collected in one 
 common body, like polypi ; among them some are disposed in a 
 star, the anuses being in the centre, and the mouths at the cir- 
 cumference; others form a cylinder in which end the anusses, 
 the mouth opening externally, while others have the viscera 
 prolonged in a common mass, and the radiated mouth and the 
 anus approximated towards the free extremity of the body. 
 A fourth kind only remains united, long after birth: these 
 when they are separated exhibit the form of a contractile 
 tube open at both ends, and in the thickness of which are 
 placed the viscera. Finally, there are others fixed to rocks, 
 which resemble two tubes, the one enclosed within the other, 
 and between whose parieties they cause the water to pass. 
 They all possess an alimentary canal with two openings, bran- 
 chias, a liver, heart and ovaries or internal buds, which, 
 without copulation, produce living young ones; they have all 
 ganglions and nervous filaments. 
 
 48. The cirrhopoda constitute a small group of animals, 
 intermediate, between the mollusca and the articulata. Their 
 short body without a head and transverse rings, is fur- 
 nished with a tunick and multivalve shell which resemble 
 those of the acephala; the mouth has lateral jaws, and along 
 the belly there are articulated appendages with a horny skin, 
 disposed in pairs, resembling the natatory feet of the tail of 
 
56 INTRODUCTION. 
 
 certain Crustacea, called cirri. The stomach is provided with 
 little cells which appear to perform the office of a liver; the in- 
 testine is simple; there is a dorsal heart and lateral branchiae, 
 also a double ovary or a mass of internal buds and a double 
 serpentine canal for the exit of the young. These animals are 
 sessile or pediculated, but always fixed; their nervous system 
 is a series of ganglions under the belly. 
 
 49. The acephalous or conchyferous mollusca, have the 
 body deprived of a head, containing all the viscera and are 
 completely enveloped, (like a book by its cover) by the man- 
 tle doubled in two, and by a calcarious shell, generally bivalve, 
 sometimes multivalve. The mouth is armed with tentacular 
 leaflets concealed under the mantle; the anus is hidden in the 
 same manner; at the other extremity there are four very large 
 branchial leaflets; the liver is very voluminous, embracing the 
 stomach and a part of the intestine which greatly varies. The 
 foot when it exists is attached between the four branchiae, and 
 consists of a fleshy mass, which moves like the tongue of the 
 mammalia. The heart is commonly single, aortic, and placed 
 near the back. They have one or two muscles for closing the 
 shell and an elastic ligament which opens it; they have also a 
 principal ganglion situated above the mouth, united to another 
 opposite by two nervous cords, and some other nerves and gan- 
 glions. They produce living young ones without copulation. 
 
 The branchiopoda, are other acephala, but few in number, 
 which in place of ieet have two fleshy arms; they appear to 
 have two aortic hearts, and a convoluted intestine surrounded 
 by the liver; neither their generation nor their nervous system 
 is well understood. 
 
 50 The gasteropoda are cephalous mollusca that generally 
 crawl on a fleshy disk placed under the belly, the back being 
 covered by the mantle that varies in length and figure, and 
 producing most commonly a univalve or multivalve shell. In 
 this class are to be found some mollusca whose organs of res- 
 piration and shell are not symmetrical. The head, placed for- 
 ward and more or less disengaged from under the mantle, pos- 
 sesses generally two, four, or six tentacula, situated above the 
 mouth, that perform the offices of feeling, seeing, and perhaps 
 
OP ANIMALS. 57 
 
 smelling. Most commonly there are small punctiform eyes, 
 belonging to the head or tentacula; the organs of digestion are 
 very varied, and there is never more than one heart, which is 
 aortic: in those that are not symmetrical, it is on the left side 
 for the greater number, and in those that are, on the right. 
 The respiratory organs vary greatly; the greater portion of them 
 have branchia?, and some breathe air. The same variety exists 
 in their modes of generation, being unisexual without copula- 
 tion, hermaphrodite with a mutual coitus, and separate sexes. 
 
 The pteropoda consist of a small group of mollusca between 
 the acephala and the cephala. 
 
 51. The cephalopoda, form a small class that comprises 
 the inarticulated animals the most complex in their organiza- 
 tion, and which, like the Crustacea, among the articulata, ap- 
 proximate the most to the vertebrata. 
 
 They are soft animals, whose bodies are wrapped in a sac 
 formed by the mantle, the sides of which project more or less 
 in fins; through its opening passes a round head, crowned with 
 feet or fleshy arms, provided with suckers which serve for 
 walking, seizing, and swimming. The mouth, situated be- 
 tween the bases of the feet, is armed with two strong jaws of 
 horn, resembling the beak of the parrot; there is a tongue that 
 bristles with horny points; an oesophagus swelled into a crop, a 
 second muscular stomach like a gizzard, and a third one that is 
 membranous; a simple and short intestine ends in the opening 
 of the sac before the neck. There is a double system of veins 
 and arteries, two branchial and one aortic ventricle. The res- 
 piratory organs are two branchiae, situated in the sac where the 
 water for breathing comes and goes. The liver is very large 
 and discharges the bile by two ducts into the third stomach. 
 These animals have a peculiar black secretion produced by a 
 gland and deposited in a reservoir. The sexes are separate; 
 there is an ovary, two oviducts, that take and convey the eggs 
 thence out of the body through two large glands that envelop 
 them with a viscid matter, and unite them in clusters; there is 
 a testicle and a vas deferens which ends in a fleshy penis by 
 the side of the anus, where terminate also a vesicula seminalis 
 and a prostate. Fecundation is performed, it is presumed, by 
 
58 INTRODUCTION. 
 
 moistening the eggs. The eye is formed by numerous mem- 
 branes, and covered by the skin, which at this place is trans- 
 parent and which is sometimes so doubled as to form folds or 
 eye-lids. Each eye has a large ganglion giving rise to innu- 
 merable nerves. The ear is a small simple cavity, sunk on 
 each side near the brain without any external canal, where a 
 small membranous bag is suspended that contains a little stone. 
 The brain is contained in a cartilaginous cavity which is a ru- 
 diment of a skull. 
 
 52. Such is the immense series of invertebrate animals. 
 They constitute, as we have seen, three different types. We 
 have also seen that in each type there is a general resemblance, 
 and also different degrees of complication and perfection in 
 their organization. 
 
 The radiata are evidently the most simple. Through some 
 of their number they approximate to the infusorii. Even the 
 most complicated among them have yet no central organ of 
 circulation, and no predominant nervous one: destitute of cen- 
 tral organs, they have no organic or vital unity. 
 
 After the radiata come the mollusca and the articulata. As 
 to the order of organic superiority of these two divisions, it is 
 difficult to determine, for on the one hand, if the articulata are 
 inferior to the mollusca as regards the vegetative organs and 
 functions, since many of them are deprived of a true circula- 
 tion, a function existing in all the mollusca, on the other, the 
 latter are inferior to the former in the development and ap- 
 proximation of the nervous masses, and above all in that in- 
 stinct which is so perfect in some of the articulata, as to bring 
 them near to the vertebrata. 
 
 OF VERTEBRATE ANIMALS. 
 
 53. Vertebrate animals, or as they are termed, the verte- 
 brata, form a type or mode of organization, to which man and 
 those animals that most resemble him belong. They resemble 
 the invertebrate in the organs of the vegetative functions, 
 while they widely differ from them in those of the animal 
 functions. Their external conformation, with the exception 
 
OF VERTEBRATE ANIMALS. 59 
 
 of almost one genus, is perfectly symmetrical, i. e. that their 
 organs of sensation and motion are disposed in pairs on 
 the two sides of an axis or of a median line. They attain a 
 great size, and it is among them that we find the largest ani- 
 mals, which is owing to the bones that sustain the soft parts. 
 Their bodies are composed of a trunk, and with very few ex- 
 ceptions, of limbs. The trunk is upheld in its whole length 
 by the spine, a column formed of moveable vertebra placed 
 one on another, at one of whose extremities is the head; while 
 the other is generally prolonged into a tail. This column, 
 partly solid, is pierced by a canal which contains the spinal 
 marrow. The head is formed by the cranium which contains 
 the brain, and by the face which consists of the jaws and the 
 receptacles of the senses. The remainder of the trunk forms 
 one or two great cavities which contain the organs of the vege- 
 tative functions. In most of them, on the sides of the column, 
 are bony arches, or ribs, that protect the great splanchnic 
 cavity, and in the greater number, these ribs are articulated 
 in front with the sternum. The limbs never exceed in num- 
 ber two pairs, sometimes one, sometimes the other of these 
 are wanting, occasionally even both: in other respects their 
 forms are varied according to their destined relative move- 
 ments. 
 
 The vertebratahave all two horizontal jaws, most commonly 
 furnished with teeth, hard bodies analogous to bones in their 
 chemical composition, and to horns in their mode of forma- 
 tion. In such as have no teeth (the bird and tortoise) we find 
 a true horny matter in place of them. In all the vertebrata, 
 the intestinal canal, extended from the mouth to the anus, and 
 presenting several enlargements, is furnished with secretory 
 glands viz: the salivary glands, the pancreas, and the liver. All 
 have arteries, veins, a heart variously formed and chyliferous 
 and lymphatic vessels. The blood is red. In one class only 
 (Fish,) are there branchia, in the remainder the respiratory 
 organ is lungs. Respiration is more or less great or perfect 
 according to the class. The organ for secreting bile, the liver, 
 receives in all the vertebrata, blood brought from the intes- 
 tines and the spleen by the vena-porta. They have all kid- 
 
60 INTRODUCTION. 
 
 neys, that secrete the urine, and the greater portion a bladder 
 or resevoir for this excrementitious humour. The sexes are 
 always separate; the female has one or two ovaries from 
 which the eggs detach themselves. The male fecundates them 
 with the spermatic fluid, but the mode of impregnation as 
 well as other phenomena of generation, greatly varies. 
 
 The muscles, independently of those that form the heart, 
 and those that belong to the skin, the mucous membrane and 
 the senses, are very numerous, and are inserted into internal 
 bones, moving on each other. All such as have lungs, have 
 also a larynx, although all have not a voice. The senses consist 
 of two eyes, two ears, the nose, the tongue and the skin; this 
 membrane being besides provided with several protecting 
 parts, but it is essentially the nervous system which peculiarly 
 distinguishes the vertebrata. In the invertebrate animals the 
 same nervous enlargements, more or less separated, send fila- 
 ments indifferently to the organs of the animal, as well as the 
 vegetative functions ; here, on the contrary, besides those gan- 
 glions whose filaments are restricted to the organs of the ve- 
 getative functions, there is a particular centre with which these 
 enlargements communicate, and from which originate or where 
 terminate the nerves of the organs of sensation and motion. 
 This centre, perfectly symmetrical, consisting of a thick cord 
 enclosed in the spine, is extended into the cranium, where it 
 presents various enlargements, and is surmounted by two 
 complex nervous organs, called cerebellum and cerebrum. 
 This nervous centre is enveloped by bones firmly united with 
 each other, that defend it from external injuries. This func- 
 tion of the bones may be regarded as one of the most impor- 
 tant they possess. 
 
 54. Besides the kinds of humours and organs common to 
 all, or at least to the generality of animals, some are found 
 among the vertebrata, which have no existence in the others; 
 these are the red blood, the lymphatic and chyliferous vessels, 
 bones, ligaments and tendons, and the serous and synovial 
 membranes. 
 
 In all the invertebrata, the nutritious liquid is of one single 
 colour, and that white or bluish, if we except the annelides 
 
OP VERTEBRATE ANIMALS. 61 
 
 where it is red. In the vertebrata, on the contrary, the arte- 
 ries, veins and heart contain red blood, a fluid composed of 
 colourless serum, in which corpuscules float, formed of a cen- 
 tral globule and a coloured envelope. Its composition is more 
 complicated than in the invertebrata. A whitish or slightly co- 
 loured liquid is contained in the chyliferous vessels, which 
 commence at the intestine, and in the lymphatics which arise 
 in every part of the body, both of which are very analogous 
 to veins, and terminate in them. 
 
 The bones are hard parts, proper to the vertebrata. They 
 are situated internally and are of an organic nature, consisting 
 in a compact mass of cellular matter, containing a large pro- 
 portion of the phosphate of lime. They serve as envelopes to 
 the nervous centres; they receive and transmit the muscular 
 motions, and finally serve as support to all the parts, and 
 thereby determine the form of the body. In the invertebrata, 
 the hard parts, in general, are exuded on to the surface of the 
 skin, and consist of shells, crusts, and scales of carbonate of 
 lime, or a horny substance. This latter kind appears again in 
 the vertebrata, where it is variously disposed, as in horns, 
 scales, feathers and hairs, parts all analogous to each other, 
 both in their composition and mode of formation. We also 
 find in the vertebrata a kind of organs which is almost pecu- 
 liar to them; they are the tendons which connect the muscles 
 with the bones, and the ligaments which surround their articu- 
 lations; these liens or ties are formed of very highly condens- 
 ed cellular membrane, whose whole function consists in their 
 tenacity. 
 
 The serous and synovial membranes are also parts formed by 
 the condensed cellular substance, disposed in the form of sacs 
 with contiguous parietes wherever the continuity of the parts 
 is interrupted; in the splanchnic cavities it separates the viscera 
 from their walls, in the moveable articulations they contain a 
 liquid which lubricates the adjoining extremities of the bones. 
 
 55. But what distinguishes the vertebrata, is not only the 
 actions of the organs proper to them, viz: a more concentrat- 
 ed nervous system, whose central parts are more voluminous, 
 whence results an appearance of intelligence which distin- 
 
62 INTRODUCTION. 
 
 guishes itself from instinct, a certain capability of instruction, 
 &c. ; it is not only the influence these organs hold over the 
 others, in order to direct their action, but it is, above all, the 
 concentration of life in the central or predominant organs 
 in the heart, in the nervous centre, and in the action of these 
 parts on each other. Even in this point of view, however, 
 there is a great difference among the vertebrata. 
 
 56. The vertebrate animals which are so much alike in 
 most of their characters, present, in fact, a very considerable 
 difference. The similitude is particularly strong in the cen- 
 tral part of the nervous system, and in its envelope, that is to 
 say, in the spinal marrow, and spine; and their differences in the 
 extremities and at the surface, as in the brain, the cranium, the 
 organs of sense, the face, the organs of motion, themembers, 
 and skin. In the same way, among the organs of the vegetative 
 functions, the heart presents many differences, but they are 
 particularly great in the organs and phenomena of respira- 
 tion; and as the action of the muscles and of the nervous sys- 
 tem depends greatly on respiration, variations in this function 
 occasion corresponding ones in the animal function. Thus in 
 the mammalia, where the circulation is double, that is, where 
 all the blood brought from the body is sent to the lungs be- 
 fore returning to it, and where respiration is aerial, the mus- 
 cular action is strong. In birds, where the circulation is dou- 
 ble, and where respiration is aerial also, is not confined to the 
 lungs, but extends itself to various parts of the body, the vi- 
 gour of the muscles is still greater; in reptiles, where the cir- 
 culation is simple, and respiration consequently partial, it is 
 weak and the movements slow, since a part only of the blood 
 is submitted to the action of the air, previous to its return to 
 the body. Fishes, it is true, have a double circulation, but 
 their respiration can not be complete, on account of the small 
 quantity of air contained in the water they respire, conse- 
 quently, as to station, they are nearly in a state of equilibrium 
 in water. Animals of the first two classes have much warmer 
 blood than those of the two latter, which on this account are 
 called the cold blooded vertebrata. 
 
 Their mode of generation, presents also a remarkable differ- 
 
OF VERTEBRATE ANIMALS. 63 
 
 ence, from which the vertebrata are divided into oviparous and 
 viviparous or mammalia. 
 
 57. The oviparous vertebrata, are particularly alike in 
 their mode of generation, they have also some common cha- 
 racters of organization in the nervous system, and in the bones 
 which envelop it. 
 
 Oviparous generation consists essentially in the germ being 
 inclosed in its envelopes, with nutritious matter sufficient to 
 nourish it until it be hatched, so that if the egg remain in the 
 interior it does not attach itself to the parietes of the oviduct, 
 but remains separate. The nutriment of the young one is con- 
 tained in a sac which is a part of its intestine, and which is 
 called the yolk. The germ is at first a mere imperceptible ap- 
 pendage, but as fast as it receives its nourishment, it increases 
 in size by the absorption of the yolk which is proportionally 
 diminished, and finally disappears near the period of hatching. 
 The embryos of the ovipari with lungs, birds, and, except the 
 batrachians, reptiles, have moreover a very vascular membrane, 
 which appears to assist in respiration, and which is a prolonga- 
 tion of the bladder: it is called the allantoid; it is not found 
 either in fishes or the batrachian reptiles, whose young are pisci- 
 form. Particular fish and reptiles retain their eggs within 
 them until the time of their hatching; such are called ovovi- 
 vipari. 
 
 The prolongation of the spinal marrow in the cranium, pre- 
 sents in the ovipari, highly developed tubercles, called the quad- 
 rigemina; the cerebrum and cerebellum, on the contrary, are 
 very slightly so, and there is no pons varolii nor corpus callo- 
 sum. The bones of the cranium are either very quickly con- 
 solidated, or remain a long time divided; their senses are not 
 as perfect as those of the vivipari; the lower jaw, which is 
 very complex, is articulated by a concave facette with a pro- 
 jecting part of the temporal bone, that is distinct from its pe- 
 trous portion; the orbits are only separated by a membrane or 
 a bony plate of the sphenoid. When they possess anterior 
 members, the clavicles unite and form a fourchette (as the 
 merry-thought of a chicken) while the elongated coracoid apo- 
 
 physes are articulated with the sternum. The larynx is sim- 
 10 
 
* 
 
 64 INTRODUCTION. 
 
 pie, and has no epiglottis &c., neither is there a complete dia- 
 phragm between the breast and the abdomen. 
 
 The ovipari are divided according to their mode of respira- 
 tion, their temperature, the atmosphere they inhabit, their mo- 
 tions, the appendages of the skin &c. into three classes: Fishes, 
 reptiles and birds. 
 
 58. Fishes are evidently organized for natation; they are 
 suspended in a fluid nearly as heavy as themselves. Many, 
 under the vertebral column, have a bladder filled with air, 
 which by its own contraction or dilatation varies the specific 
 gravity of the animal. The head variable in its form, is of a 
 very complicated structure, as regards the cranium, the jaws, 
 and the distribution of the teeth. The limbs are abbreviated 
 and formed into fins; other fins occupy the back, the top of the 
 tail and its extremity. The number of members varies, most 
 generally there are four, sometimes only two, and in some 
 they are totally wanting. Their position and connexion with 
 the trunk also vary greatly, so do the organs of digestion; the 
 pancreas is generally superseded by intestinal appendages. 
 The circulation is double, i. e. all the blood passes through the 
 respiratory organs, but the atmosphere respired is aerated wa- 
 ter: for this purpose, they have on the sides of the neck, an 
 apparatus of organs called branchiae. These are leaflets attach- 
 ed to little lateral arches of the os hyoides, and composed of 
 numerous membranous laminas, covered by a net-work of numer- 
 ous blood-vessels; this opening, is, besides, furnished with a 
 branchial membrane, supported by the processes of the hoyoi- 
 deus and a bony operculum. The water which the fish com- 
 presses in its mouth as if to swallow it, escapes between the 
 divisions of the branchiae and acts on the blood. The heart has 
 only one auricle, which receives the veins of the body, and one 
 branchial ventricle. The blood, after having traversed the 
 branchiae, is directed into a large vessel under the spine, which, 
 exercising the functions of ventricle and aorta, transmits it to 
 every part of the body. 
 
 Fishes have elongated kidneys stretched along the sides of 
 the spine and a bladder. Their testicles are two enormous 
 glands, generally known by the name of milts, (laite) their 
 
OP VERTEBRATE ANIMALS. 65 
 
 ovaries are not less voluminous; most of them first lay their 
 eggs, and afterwards the male fecundates them; with some, 
 however, copulation and an intromission of sperm takes place, 
 the latter heing mostly ovoviviparous. The muscles which form 
 so large a portion of the mass of their bodies are white, exces- 
 sively irritable, and are less perfectly organized than those of 
 the other classes. It is the same with the bones: in some of them 
 (thechondropterygii) the bones remain cartilaginous: the cal- 
 carious substance forms no filaments, but remains in isolated 
 grains: in some of them, even the articulations of the spine do 
 not exist, and iu the others, the bones, although fibrous and 
 calcarious, differ greatly in solidity, and are remarkably at 
 variance with those of the other classes. The ribs are often 
 soldered to the transverse apophyses. The senses are imper- 
 fect; the nostrils are mere rudimental pits at the end of the 
 nose; the cornea of the eye is flat, there is but little aqueous 
 humour, and the crystalline is almost spherical; the ear con- 
 sists of a vestibulary sac in which are suspended bones of a 
 stony hardness, and in three semi-circular membranous canals, 
 commonly placed in the hollow of the cranium: some genera 
 only have a fenestra ovalis, opening externally; the tongue is 
 most commonly bony and dentated, or horny; the whole skin 
 of the greater portion of them is covered with scales. Some 
 have fleshy cirri or filaments, which may serve for the sense of 
 touch. The prolongation of the spinal marrow into the cra- 
 nium terminates anteriorly by enlargements, whence originate 
 the olfactory nerves. 
 
 The class of fishes in the nature of the skeleton, and in the 
 mode of generation, offers a tolerably well defined division, 
 viz. the cartilaginous, and the bony. 
 
 It is in this class of the vertebrata that we find a genus (that 
 of the pleuronectes or flat fishes) where the head is defective in 
 symmetry, such as the two eyes being on the same side. 
 
 59. Reptiles offer in their figure, in their structure, and in 
 their functions, much greater varieties, than any of the three 
 other classes of the vertebrata. In fact, some have four feet, 
 others have two before, a third, two behind, and a fourth, 
 none at all. In some, the body is covered with scales, in others, 
 
tiU INTRODUCTION. 
 
 the skin is naked. Some of them are pisciform in their fatal 
 state, and as they advance to maturity undergo a true metamor- 
 phosis. The organs of digestion greatly vary; the circulation 
 is simple and the respiration partial, that is, the heart, otherwise 
 very variable, transmits the blood into an artery of which one 
 branch only goes to the lungs, the result of which is, that in 
 each circuit of the blood, a part of it only is submitted to res- 
 piration. Their lungs are shaped like bags, or at least have 
 large cells. They can suspend the respiratory process, with- 
 out stopping the circulation: their blood is cold. The quantity 
 of respiration is not the same in, this class, the pulmonary ar- 
 tery not being in all, in the same ratio with the aortic trunk 
 from which it arises. They have a trachea and larynx, al- 
 though voice is not common to all: the alligator is another 
 exception. The females have a double ovary and two ovi- 
 ducts. Some males have a bifurcated penis, others have none. 
 None of them hatch their eggs. The irritability of the mus- 
 cles is such that it continues long after they are separated 
 from the nervous system, and even from the rest of the body. 
 Their sensations are obtuse. Their nostrils traverse the face, 
 but the ear is incomplete, being confined to a vestibule con- 
 taining soft bones, the semi-circular canals, and in some a 
 rudiment of a cochlea. We also find under the skin the rudi- 
 ments of the bone of the tympanum. The crocodiles alone have 
 an external auricular opening. The brain, which is small, may 
 he taken away as well as the head, and motion still continue. 
 Many remain torpid during a part of the year. 
 
 From their great variety of organization reptiles have been 
 divided into several families. 
 
 The chelonia or tortoises, have a heart with two auricles, 
 each of which receives a different blood, and with one ventri- 
 cle, having two unequal and communicating cavities, in which 
 the blood from the auricles is mingled. These animals are 
 enveloped by an upper shell formed by the ribs and vertebral 
 laminae, and by an under one formed by the sternum, both 
 covered by the skin, and by a horny or scaly matter exuded 
 from it. In respiration, the air is drawn in by the nostrils, and 
 forced into the larynx by a sort of deglutition. The male has 
 a simple canalated penis. The female lays very hard eggs. 
 
OP VERTEBRATE ANIMALS. 67 
 
 They live without eating for months and even years, and sur- 
 vive decapitation several weeks. 
 
 The sauria or lizards, crocodiles, &c., have hearts resembling 
 that of the tortoise; the ribs are moveable for the purpose of 
 respiration and the lungs greatly extended. The eggs have an 
 envelope more or less hard. They have teeth, nails and scales. 
 The penis is either simple or double. 
 
 The ophidia have a heart with two auricles, and no feet. 
 Some of them are venomous. Those which are the most so 
 have insulated fangs and a peculiar disposition of the jaw. 
 Their superior maxillary bones are very small, placed on a 
 long moveable pedicle, analogous to the external pterygoid 
 apophysis; in this is a tooth pierced by a little opening, through 
 which is ejected the poisonous fluid that is secreted by a con- 
 siderable gland seated under the eye. This tooth, together 
 with several reproductive germs of the same, being placed on 
 the maxilla, is hidden by the moveability of the latter, (when 
 the reptile does not wish to use it) in a fold of the gum. 
 
 The batrachians or frogs, toads and salamanders have a heart 
 with but one auricle, and one ventricle. They have lungs, and 
 while young, branchiae similar to those of fishes. In this first 
 state, the circulation is like that of fishes; the artery is divided 
 and distributed in the branchiae; the vessels there unite in an 
 aortic trunk which supplies the body and even the lungs. 
 When the branchiae disappear their arteries are obliterated, 
 with the exception of two branches which unite to form the 
 aorta, and each of which send a small ramification to the lungs. 
 The eggs are membranous, and are fecundated during the time 
 of their being laid or afterwards. At its birth the young one 
 has branchiae and no feet; the first disappear as it advances in 
 age, and the feet are developed. Some preserve their branchiae 
 for life. 
 
 60. Birds are evidently organized for flight; their figure, 
 the proportion of their parts, their great powers of respiration, 
 whence result their specific lightness and great muscular force, 
 are all combined for this mode of motion. They are biped, 
 their anterior members being solely destined for flight. The 
 chest and abdomen form one single and great cavity, whose 
 
 
68 INTRODUCTION. 
 
 vertebrae have but little motion; the sternum is of great extent, 
 and still further augmented by a projecting blade, resembling 
 a keel. The sternal as well as the vertebral part of the ribs 
 is bony; in this part of the trunk every thing is disposed, so as 
 to give a solid support and muscular attachments to the wings. 
 The shoulders are formed by the merry thought, (the four- 
 chette) the ossa coracokles, which are very strong, and by elon- 
 gated and feeble scapulae. The wing is supported by the hu- 
 merus, the two bones of the fore-arm and the hand, which is 
 lengthened and has a finger, and two others that are rudimental; 
 it has a range of elastic quills. The pelvis, which is very long, 
 furnish insertions for the muscles of the inferior members, and 
 its bones are sufficiently separated, to allow room for the de- 
 velopment of the eggs. The lower limbs are formed of the 
 femur, of the tibia, and of the fibula, which are joined to it by 
 an articulation with a spring, which keeps it extended without 
 any muscular effort. There are muscles, also, that go from 
 the pelvis to the toes, passing over the knee and heel, so that 
 the toes are flexed by the weight of the body. The tarsus and 
 metatarsus, are formed by one single bone, terminated below 
 by three pulleys. There is most generally one great, and four 
 other toes, diverging from each other, the number of whose 
 joints increase from the great one, which has but two, to the 
 external one, which has five. The neck is lengthened, is com- 
 posed of many vertebrae, and is very moveable; the coccygis 
 is extremely short and furnished with quills like the wings. 
 The brain, whose characters are similar to those of the other 
 oviparous vertebrata, is remarkable by its size, as compared to 
 that of the body, which is considerable; but this does not de- 
 pend upon its hemispheres, which are small. The skin of 
 birds, is, commonly, covered with feathers composed of a hol- 
 low stem and barbs; the skin is scaly on the superior surface 
 of the toes, and callous beneath; the sense of touch, must con- 
 sequently be weak. The eye is furnished with three moveable 
 lids; the cornea is very convex, the crystalline lens is flat, and 
 the vitreous body small. The crystalline has a membrane which 
 appears intended to move it. The anterior part of the eye is 
 encircled with bony pieces. Birds see with great clearness, 
 
OF VERTEBRATE ANIMALS 69 
 
 both far and near. The ear a little more complete than in the 
 other ovipari, has no stones in the vestibule; the cochlea is 
 somewhat curved; there is a small bone, between the fenestra 
 ovalis and the tympanum, which is deprived of a conch, ex- 
 cept in the nocturnal genera. The organ of smell, concealed 
 in the base of the beak, has generally three cartilaginous tur- 
 binated bones and no sinus. The tongue is but slightly mus- 
 cular, and is supported by a bony projection of the hyoides. 
 The rings of the trachea are entire, at its bifurcation there is a 
 glottis or inferior larynx, where voice is produced; the supe- 
 rior larynx is very simple. The lungs, which have no lobes, 
 attached to the ribs, permit air to pass into several cavities of 
 the body, the breast, the axillae, and even of the bones; this 
 augments their specific lightness and multiplies respiration. 
 The upper maxilla is principally formed by the inter-maxillary 
 bones, and is prolonged backward into two arches, one inter- 
 nal made by the ossa palati, and the other external, by the 
 maxillar and jugal bones, both of which rest on the square or 
 tympanal bone, which is moveable; it is joined to the craniu 
 by elastic laminae. Both jaws are covered with horn, whic 
 supplies the want of teeth, and which sometimes has their form. 
 The stomach is composed of three parts more or less distinct: 
 the crop, which is sometimes wanting, the membranous stomach 
 furnished with numerous secretory follicles, and the gizzard, 
 which has two strong muscles, and is lined by a coriacious 
 membrane. In birds of prey, however, the gizzard is very 
 thin, and not very distinct from the other stomach. The spleen 
 small, the liver has two ducts, and the pancreas is considera- 
 te; there are two appendages to the rectum, sometimes one, 
 md in some genera none, which appear to be the remains of 
 
 allantoid. 
 
 The rectum, the ureters, and the spermatic vessels or the ovi- 
 luct, communicate with a cavity called the cloaca, which opens 
 it the anus. The testicles are internal and under the loins ; there 
 is but one ovary and one oviduct. Most birds copulate by the 
 simple approximation of the anus; some genera, however, have 
 a small canulated penis. The egg, detached from the ovary, 
 is composed of the germ and yolk only; it becomes enveloped 
 
70 INTRODUCTION. 
 
 by the white in the oviduct, and at the bottom of the same 
 canal receives its shell. The heat of the weather, or more 
 commonly, maternal incubation, develops the young. 
 
 OF THE VIVIPAROUS VERTEBRATED ANIMALS. 
 
 61. Viviparous vertebrata, or mammalia, among which is 
 man, differ from the ovipari, not only in their mode of genera- 
 tion and in their quantum of respiration, but are particularly 
 distinguished by the most perfect animal functions, and a 
 greater intelligence, less under the domination of instinct, 
 and more capable of perfectiveness. 
 
 Their general conformation is that of the vertebrata. The 
 splanchnic cavity of the trunk is divided by a complete muscu- 
 lar partition called the diaphragm. With one single exception, 
 they have seven vertebrae in the neck; they have a sternum to 
 which the first ribs are attached. The head is always articu- 
 lated with the first vertebra by two condyles. The cranium 
 is very similar in its composition. The occipital, sphenoidal, 
 ethmoidal, parietal, frontal and temporal bones, always exist; 
 in the foetus several of these bones consist of different pieces. 
 The face also has but little variety; it is essentially composed 
 of the superior maxilla, the inter-maxillary bones, the ossa pa- 
 lati, the vomer, the bones of the nose, the inferior ossa turbi- 
 nata, and of the jugal and lacrymal bones: these united form 
 the upper jaw which is fixed to the cranium: the lower one, 
 formed of two pieces, is articulated by projecting condyles to 
 fixed temporal bones. An os hyoides, suspended to the cra- 
 nium by ligaments, supports the tongue, which is always fleshy. 
 The anterior or superior members originate from a bony cinc- 
 ture or shoulder, formed by the scapula, not articulated with 
 the spine, supported in many of the mammalia by the sternum, 
 by means of a clavicle. The arm is formed of one single bone ; 
 the fore-arm of two, the radius and ulna; the hand which ter- 
 minates these limbs, is composed of two ranges of small bones 
 called the carpus, of a range of bones called metacarpus, and of 
 fingers, each of which consists of three bones called phalanges. 
 The posterior or lower limbs are similarly formed, and this 
 
OP VIVIPAROUS VERTEBRATA. 71 
 
 similarity is greater or less in proportion as the functions for 
 which the limbs are destined, are more or less alike. Besides 
 this, in all the mammalia, with the exception of the cetacea3, 
 the lower limb commences by a bony girdle or pelvis, formed 
 by the bones of the hip fastened to the spine: at first these 
 bones are formed of three distinct parts, the illium, the pubis, 
 and the ischium. The thigh is formed of one single bone, the 
 leg of two principal ones, the tibia and fibula; the foot which 
 terminates this member is composed of a tarsus, metatarsus, 
 and toes. 
 
 The muscles possess a moderate power of contraction; but 
 their irritability is very dependent on the nervous system. 
 The motion is that of walking. Flight can take place in some, 
 by means of elongated limbs and extended membranes; while 
 others again, having their limbs very much shortened, can only 
 swim. The nervous system of the mammalia is chiefly charac- 
 terized by the state of the brain and cerebellum. The latter has 
 lateral lobes or voluminous hemispheres, and there is always a 
 pons varolii under the spinal medulla. In like manner the 
 cerebrum always has the corpora striata, and is formed of 
 two voluminous hemispheres, furnished with circumvolutions, 
 forming two lateral ventricles, connected by the corpus callo- 
 sum. 
 
 The eyes, lodged in the orbits, are defended by two lids, 
 and a vestige of a third; the sclerotica is simply fibrous; the 
 crystalline is fixed by the ciliary processes. In all of them, 
 the ear has a perfect labyrinth, with a cochlea, a. drum and 
 a membrana tympani and small bones. The nasal fossa tra- 
 verse the face, have the ossa turbinata, and extend into the 
 sinuses of the bones. The tongue is fleshy and attached to 
 the os hyoides. The skin of the mammalia, generally is co- 
 vered with hair; the cetaceae alone are wholly deprived of it. 
 
 The intestinal canal is covered with the peritoneum, sus- 
 pended to the mesentery, a fold of that membrane which en- 
 closes the conglobate glands of the chyliferous vessels, and 
 covered with a floating extension of the same membrane, 
 called the epiploon. They have a urinary bladder, that 
 opens, with very few exceptions, into the orifice of the organs 
 11 
 
72 INTRODUCTION. 
 
 of generation. The cellular lungs and the heart are contained 
 in a cavity formed by the ribs, and separated from the abdo- 
 men by the diaphragm, where the surface is free. The circu- 
 lation is double, and respiration aerial and simple. There is a 
 larynx at the upper extremity of the trachea, which opens 
 into the posterior fauces, this communication depending on a 
 moveable, fleshy veil, called the veil of the palate, or the ve- 
 lum pendulum palati. 
 
 What principally distinguishes the organization of the 
 mammalia, is their generation. It is essentially viviparous, 
 i. e. the membranous egg descends and fixes itself in the ute- 
 rus after conception, which requires a coitus, by which the 
 sperm of the male is thrown into the organs of the female. 
 They have all, like other vertebrate vivipari, at least, in the 
 beginning, an umbilical or intestinal vesicle ; they have also, 
 like the lung'd ovipari, an allantoid; but besides this, they 
 have other envelopes, the superior of which, the chorion, 
 fixes itself to the parieties of the uterus by one or more 
 plexuses of vessels, called placentas, that establish a communi- 
 cation between it and the mother, by which it receives nou- 
 rishment, and probably oxygen. When the foetus has acquir- 
 ed the necessary developement, it is expelled with the rup- 
 tured membranes. The mammae, secretory glands, produce 
 milk, for the support of the young, as long as they need it. 
 
 It is to this kind of organization, presenting, however, cer- 
 tain variations, that man belongs. 
 
 62. The mammalia have some organs peculiar to them, 
 such as the hairs of the skin, and the mammae; otherwise they 
 only differ from the other vertebrata, in the greater deve- 
 lopement of certain organs, as the ear for instance, the brain, 
 &c., or by different combinations of the organs of circulation, 
 respiration and motion. 
 
 The blood of the mammalia, differs from that of the ovipari 
 in the form of its coloured particles ; in the former, they are 
 circular, or rather lenticular; whereas in the latter, they are 
 ovals, or flattened ovoids. 
 
 The hairs of the mammalia are not essentially different 
 from the other horny appendages of the skin: like all organs 
 
OF VIVIPAROUS VERTEBRATA. 73 
 
 of this description, they are produced by an excretion on the 
 surface of that membrane. 
 
 The mammae, are also absolutely similar to the other glan- 
 dular secretory organs. 
 
 63. The mammalia, however, still present great varieties 
 in their organization; either in the organs of touch, which 
 are the more perfect, in proportion as the fingers are more 
 numerous and pliable, and less enveloped by the nail ; or in 
 the organs of mastication, and consequently in the rest of the 
 digestive organs, or finally, in the organs of generation. The 
 different combinations of these varieties, which occasion many 
 others in all the functions, and even in the intelligence of the 
 animal, have caused this class to be divided into several orders, 
 among which is that of the bimana, formed of one single 
 genus, Homo, or man. 
 
 64. Man is distinguished from the other mammalia, by 
 some slight differences in the vegetative functions, by some 
 others, more important in the organs of the animal functions, 
 but principally by his intelligence. 
 
 Intelligence, which distinguishes man, is characterized, 
 above all, by consciousness, reason and free will, by a moral 
 sentiment, and that of a divine First Cause. 
 
 Besides this, of all the mammalia, man has the hemispheres 
 of his cerebrum and cerebellum, the most greatly developed, 
 and most largely furnished with circumvolutions. This vo- 
 lume of the hemispheres, appears considerable, particularly in 
 comparing it with the medulla, the nerves, the senses and the 
 muscles. His cerebral functions are greatly developed, and 
 very distinct from instinct. He is gifted with speech, and 
 lives in society. He is the only true, two handed, and biped 
 animal; his whole body is organized for a vertical position, 
 and his hands are evidently reserved for other uses, than for 
 standing on. 
 
 The heart is directed obliquely over the diaphragm, and the 
 aorta somewhat differently arranged from that in the quadru- 
 peds. The organs of digestion are fitted for a varied diet, 
 principally vegetable. The penis is free, and without any in^ 
 
74 INTRODUCTION. 
 
 ternal bone; the uterus is a simple oval cavity ; the mammae 
 two only in number, are seated in front of the chest. 
 
 But as the remainder of this work is devoted to an exami- 
 nation of the human body, it would be superfluous to dwell 
 upon characters, which will be considered in their proper 
 places. * 
 
 SECTION II. 
 
 OF THE HUMAN BODY. 
 
 65. Man, as is evident, partakes of the general characters 
 of bodies, of organized beings, of animals, of the vertebrata, 
 of the mammalia ; he has besides this, like all others, those 
 which are peculiar to him: it is the study of all these charac- 
 ters, either of the external and internal conformation, or of their 
 phenomena, that constitutes the object of Anthropology, or the 
 science of man. The immediate end of human anatomy, also 
 called anthropotomy, is a knowledge of the body, that is to 
 say, of all the parts that compose it, and of their mutual ar- 
 rangement. 
 
 66. The anatomist may study the human body in two 
 different states; in the one most common, that proper to the 
 species, and alone compatible with health; or, on the contrary, 
 in its deviations from the natural order. In the first instance, 
 it is the anatomy of the healthy man, hygid anatomy, if we 
 may so express it; in the second, it is morbid anatomy. 
 
 In the study of anatomy, we may consider the whole human 
 body, examine the general characters of all its organs, of all its 
 humours, &c. ; these are the general views of anatomy. We may, 
 by uniting the multiple organs, in genera, or in systems, accord- 
 ing to their analogies of texture, confine ourselves to generic 
 characters, abstracting all the specific differences of the organs; 
 and as for those, which without being mutiple, are extended 
 to all the body, we may only consider the general characters, 
 overlooking the local differences they present in the various 
 
 * Vide Blumenbach "de varietate nativa generis humane Laurence, 
 "Lectures on Physiology, Zoology and the natural history of man. 
 
OF THE HUMAN BODY. 75 
 
 regions; such is general anatomy; it imparts a knowledge of 
 the subject, a little more precise, than the more general view 
 above mentioned. But in order to know the human body, 
 in a positive and useful way, we must add to this, an exact 
 knowledge of each organ, in particular, and of each of its re- 
 gions; such is the object of special anatomy. 
 
 General anatomy, considering together the organs similar as 
 to their texture, and confining itself to what may be generic or 
 common to them all, has for its special, but not its only object, 
 their texture. The special anatomy of the organs, improperly 
 styled descriptive anatomy, treats particularly of their con- 
 formation, for it is principally in this, that they differ from each 
 other; their respective situations, is the essential object of 
 topographical anatomy, or the anatomy of the regions. 
 
 67. The external form of the human body, is symmetri- 
 trical;* it is divided into two lateral similar halves, by a me- 
 dian verticle line. This line is even marked, in some places, 
 where it forms what are called raphae or seams, which, in 
 fact, appears to result from a sort of sewing, or junction of 
 the two lateral portions, originally separated. This symme- 
 try is not equally perfect in all parts of the body; it is more 
 so in the organs of animal functions, and less so in those of the 
 vegetative functions, particularly in those of nutrition. In 
 fact, the bones, the nervous system, the senses, and the mus- 
 cles, are the most symmetrical parts, while the organs of di- 
 gestion, of circulation, and of respiration, are less so than the 
 genital organs. It would not be exactly correct, however, 
 to say that symmetry belongs to the former, and is foreign to 
 the latter ; it belongs, generally, more to the external parts, 
 and is less perfect in those that are deeply seated; thus the 
 lachrymal and salivary glands, the thyroid gland, the mammae, 
 the testicles, and all the organs of the functions of nutrition and 
 generation, are symmetrical; while the nerves of the*larynx, 
 of the stomach, of the intestines, and the diaphragm, are not. 
 It is also to be observed, that certain parts, which are develop- 
 ed at a later period are less symmetrical than those of the 
 
 * See, among others, Bichat, Reck. Physiol sur la vie and la mort- 
 Meckel, Beitz. zur vergl. anat. Leipz. 1812. 
 
76 INTRODUCTION. 
 
 same kind, which are previously developed: thus, in the 
 nervous system, the medulla, which is first developed, is more 
 symmetrical than the brain ; the ribs are less symmetrical than 
 the spinal column, and more so than the sternum. Finally, we 
 may further observe, that the parts are most symmetrical at the 
 period of their formation, and that this kind of regularity, 
 afterwards changes: the stomach, intestines and liver, are 
 less irregular at first, than at a later period; the vertebral 
 column, at first exactly median, gradually inclines to the left, 
 from the predominance of the right arm, and thence results 
 the inclination of the nose, the unequal elevation of the testi- 
 cles, the frequency of hernia on the right side, &c. Sometimes 
 such a derangement of this symmetry is observed, that the or- 
 gans of one side, occupy the other, and vice versa; this is called 
 a transposition of the viscera. In this case, which happens in 
 about one, of three or four thousand subjects, and that I have 
 seen four or five times, the trilobated lung, the liver and the 
 ca3cum, are on the left, while the bilobated lung, the apex of 
 the heart, the spleen, the sygmoid portion of the colon, &e. 
 are on the right: Individuals thus situated, are not, however, 
 left-handed on this account. The diseases, which affect the 
 symmetrical organs, and those whose seat is in parts that 
 are not so, present a very remarkable difference. It has been 
 even asserted, but upon hypothetical views, that each side of 
 the body, has a greater predisposition to certain maladies, than 
 its fellow.* 
 
 Comparisons have also been established, and analogies sought 
 for, between the upper and lower halves of the body. The 
 analogy between the limbs is evident; the shoulders and pel- 
 vis, the leg and the arm, the hand and the foot, are construct- 
 ed on one plan, and differ only so far as their different func- 
 tions require. As to the analogy, supposed to have been 
 found in man, as in the articulata, between different sections 
 of his trunk, and between the limbs, and the jaws, it rests on 
 a comparison between objects too dissimilar to admit of it. 
 
 Carried away by a forced analogy with the radiata, anato- 
 
 * See Mehlis, de rnorbis Jiominis dextri et sinistri. Getting. 1818. 
 
OF THE HUMAN BODY. 77 
 
 mists have sought for parts in the anterior portion of the trunk, 
 corresponding to the vertebral column; they think they have 
 found them in the sternum: observation here shows no rea- 
 sonable approximation, except between ihe anterior and pos- 
 terior muscles of the spine. Let us abandon then, compari- 
 sons which can tend to no good or useful purpose. 
 
 68. The human body is divided like that of the other 
 vertebrata, into trunk and members. The trunk is the cen- 
 tral and principal part, that which contains the organs most 
 essential to life^ or the viscera. These parts are lodged in 
 three cavities; the inferior is the abdomen, and contains the 
 organs of digestion, of the urinary secretion, and of genera- 
 tion; the middle one, the thorax, contains the organs of respi- 
 ration and circulation, while the superior, the head, whose 
 cavity is continued into the vertebral column, contains the 
 nervous centre and the senses. It may have been already re- 
 marked, (sec. 1,) how much this distribution of the viscera is 
 in relation with their importance in the animal kingdom. 
 We shall see hereafter, that it is equally so with the order of 
 their developement. Considered as a whole, the trunk from 
 before backward, presents a face anterior or external, one pos- 
 terior or dorsal, and sides; it presents two extremities, the one 
 superior or cephalic, the other inferior or pelvic. The limbs 
 or members, articulated appendages, destined for motion, are 
 divided into superior or thoracic, and inferior or abdominal, 
 both being divided, in several places, by articulations. The 
 different portions of the trunk and members, are again subdi- 
 vided into a certain number of regions or parts, all distinct 
 and important, on account of the organs placed there. These 
 divisions and subdivisions of the body, are principally deter- 
 mined by the bones. A knowledge of the regions is neces- 
 sary, in order to determine the exact situation of the organs, 
 and their profound study, the surest or rather the only means 
 of knowing the respective situation of parts: this knowledge 
 constitutes a sort of topographical anatomy, which is of the 
 greatest importance. 
 
 69. The human body, like all those that are organized, 
 is composed of solid and fluid parts, which have a similar 
 
78 INTRODUCTION. 
 
 composition, and which are continually changed into each 
 other. The fluids are very abundant, and their mass is great- 
 ly superior to that of the solids. The exact proportion of the 
 one to the other, however, can not he determined, because on 
 the one hand, certain fluids, as oil, separate from the solids 
 with great difficulty, and on the other, many of the solids can 
 be rendered fluid, and during dessication, disappear among 
 the fluids, and are dissipated with them. To determine this 
 proportion of the liquids to the solids, however, attempts have 
 been made, both by dessicating the parts in stoves or ovens, 
 and by mummifaction; some have considered the proportion 
 as six of the fluids, to one of the solids, while others place it 
 as nine to one. The examination of a mummy, gave a still 
 greater proportion, as this adult mummy weighed only seven 
 and a half pounds. But could the proportion be exactly 
 ascertained in any one case, it would vary according to'the 
 individual, the age, sex, constitution &c., inevitably occasion- 
 ing a marked difference. 
 
 Both the solids and fluids are formed of globules, and of an 
 amorphous substance, liquid in the one, and concrete in the 
 other. 
 
 70. The chemical composition* of the solids and fluids of 
 the human body, results from a certain number of immediate 
 materials, the chief of which are gelatine, albumen, mucus, 
 fibrine, oil, water, sugar resin, urea, picrocholine, osmazome, 
 zoohematine, phosophate and carbonate of lime, &c. These 
 substances themselves are compound, and the ultimate elements 
 found in the human body, are oxygen, hydrogen, carbon, nitro- 
 gen, phosphorus, calciunijsulphur, potassium, sodium, chlorine, 
 iron and manganese we even find magnesium and silicium. 
 
 These elementary substances, in order to form the imme- 
 diate materials, and these latter, to compose the solid and fluid 
 parts of the human body, are combined in the acts of nutrition 
 and generation in a way that chemistry can not imitate: and it 
 is precisely this act of formation or organization that charac- 
 terizes life. 
 
 * See Orfila. Chimie Medicale. 
 
OF THE FLUIDS. 79 
 
 OF THE FLUIDS. 
 
 71. The fluids, or the humours* of the human body, are 
 contained in the solids, and penetrate all their parts. They 
 are composed of molecules, coming from without for the sup- 
 port of the body, and of those which are detached from it to 
 be rejected. Their fluidity is owing, not only to caloric and 
 water, like that of fluids foreign to the organization, but like 
 their composition, it depends upon the vital action. The fluids 
 differ from each other, one being gaseous, another vaporous, 
 and a third a liquid more or less flowing; they also differ in 
 colour; their composition too varies, but it is peculiar to them, 
 and can not be imitated by art. 
 
 The fluids may be divided into three kinds, 1st, the blood, a 
 central mass, to which flow, and from which emanate all the 
 others; 2d, the humours which go to the blood from without; 
 3d, those which emanate from it. 
 
 72. The blood is a liquid of a red colour, and of a peculiar 
 odour; it has a nauseous and slightly saline taste; its tempera- 
 ture is that of the body, of which it is even the warmest por- 
 tion; it is viscid to the touch; its specific gravity is about 105, 
 water weighing 100. It is contained in the heart, and san- 
 guiferous vessels. Its quantity in the adult is considerable, but 
 variable. This quantity has been very differently estimated, 
 varying from eight or ten pounds, to eighty or a hundred. 
 
 73. Microscopic observers have made the following ob- 
 servations upon this fluid: the blood is composed of a serous 
 vehicle in which red microscopic globules, are held in suspen- 
 sion; these bodies have been generally considered, either as 
 spheres, marked with a luminous point in the centre, or as be- 
 ing pierced and consequently of ao annular form. Hewson, on 
 the contrary, conceived the red particles of the human blood to 
 be lenticular. The important observations of Messrs. Prevost 
 and Dumas and my own, have given the same result. Mr. 
 Home, like Dr. Young, considered the flattening as subsequent 
 
 * See Plenck. Hygrologia corporis humani Chaussier. Table synoptiquc 
 des humeurs. 
 
 12 
 
80 INTRODUCTION. 
 
 to the exit of the blood, and that it depended on its separation 
 from the colouring matter. The particles, are, in fact, com- 
 posed of central globules, transparent, whitish, and with a red 
 envelope, less diaphanous, formed like compressed spheres-, 
 The diameter of the particles, in the human species, is about 
 the one hundred fiftieth of a millimetre. As long as the blood 
 is contained in the vessels, and is in motion there, things re- 
 main in this state. 
 
 74. The blood, out of its vessels, and while it retains its 
 warmth, exhales a vapour formed of water, and of an animal 
 matter susceptible of putrefaction. It soon coagulates, yield- 
 ing, probably, a little warmth, and gives out a large quan- 
 tity of carbonic acid gas. This disengagement of the gas, but 
 little sensible while the blood is subjected to atmospheric pres- 
 sure, manifesting itself only by the formation of canals in the in- 
 terior of the coagulum, takes place on the outside of the clot, 
 when it is placed under the exhausted receiver of the air 
 pump. We must not confound this extrication of gas and va- 
 pour from the blood when taken from its vessels, with a pre- 
 tended gas that has been supposed to circulate with it. 
 
 Shortly after the blood has coagulated into a single mass, it 
 separates into two parts; the coagulum contracting, presses out 
 the fluid part or the serum, it contained. This contraction 
 continues, and consequently, the quantity of this expressed se- 
 rum augments until putrefaction takes place. Generally the 
 upper surface of the coagulum, contracting more than the rest, 
 becomes concave. If the clot be held for a long time under a 
 small stream of water and gently pressed, the water carries 
 away the colouring matter or cruor, and there remains a white 
 fibrous mass. Thus by coagulation and washing, the blood is 
 divided into serum, cruor, and fibrine. 
 
 But let us see what takes place during these operations: as 
 soon as the blood is out of its vessels, the colouring matter of 
 the particles leaves the central white globules, and tho latter, 
 deprived of their envelope, unite to each other and form fila- 
 ments which interweave themselves, forming a net-work, in 
 which are contained both the colouring matter, and many en- 
 tire particles that have not undergone this decomposition. 
 
OP THE FLUIDS. . 81 
 
 During the washing and squeezing of the clot, both the free 
 colouring matter, and particles that remain entire, and that 
 contain white globules in their centres, are carried away by 
 the water at the same time. 
 
 The blood, then, contains three principal materials, the se- 
 rum, the white globules, and the colouring matter that en- 
 velops them: the two last united in the fluid blood, and form- 
 ing the colouring particles, separate, in a great measure, soon 
 after the blood is drawn from the vessels. These materials 
 are in very different proportions, according to the various cir- 
 cumstances of age, sex, constitution, disease, &c. &e. : in the 
 adult and healthy man, the dried, colouring particles consti- 
 tute a little more than an eighth of the total weight of the 
 blood. 
 
 75. The serum has a pale, yellowish green colour; it has 
 the taste, smell, and feel of blood; it is alkaline; it coagulates 
 at about 69. C. It then resembles the white of a cooked egg, 
 and contains in its vacunse, a substance that has been taken for 
 gelatine, and which appears to be mucus. The constituent 
 parts of the serum are, water, albumen, soda, and salts of soda. 
 According to M. Brand, we may consider the serum, which is 
 a liquid, and almost pure albumen, as an albuminate of soda 
 with an excess of base. The coagulation appears to depend 
 upon the neutralization of the souda necessary to its fluidity; 
 alcohol and most of the acids, produce this coagulation by re- 
 moving the soda; and by the action of the galvanic pile as well 
 as by that of heat, the soda transforms a small portion of the 
 albumen into mucus, while the remainder coagulates. The 
 albumen and the serum itself, still present some peculiarities 
 worthy of remark; it is that coagulated albumen, presents glo- 
 bules under the microscope, and that the serum, preserved in 
 a liquid state, in a proof glass for a few days, gradually pro- 
 duces globules, that are deposited at the bottom, and which ex- 
 perience a singular movement of ascent and descent, on heat- 
 ing the glass by holding it in the hand; we must also observe, 
 that coagulated albumen, has the closest analogy with fibrine, 
 from which, perhaps, it does not in any way differ. 
 76. The cruor of the blood, or the colouring matter obtain- 
 
82 INTRODUCTION. 
 
 ed by washing it, is always a mixture of the free red matter of 
 the globules enveloped in the same matter, and of serum. We 
 consequently find, that the most able chemists, have as yet, 
 learned but little respecting Jhe colouring matter of the blood, 
 or the zoohematine. This substance, insoluble in water, but 
 capable of an extraordinary division in it, so as to pass through 
 the filter, is composed of an animal matter in combination with 
 the peroxide of iron. The red colour of the blood has different 
 shades. 
 
 77. The fibrine of the blood, or the coagulable lymph of 
 some authors, resembles tenacious elastic downy fibres, pre- 
 senting under the microscope the aspect of the muscular fibre, 
 being composed of white globules similar to those of the co- 
 loured particles of the blood; the fibYine also, like the muscular 
 fibre, being placed in water, resolves itself into globules pre- 
 vious to putrefaction. This coagulable or plastic substance, 
 as well as albumen, appears to be the medium of agglutination 
 which occasions the reunion and adherence of divided parts 
 of the body. 
 
 The blood contains also a fatty or oily matter. 
 
 78. The blood contained in the arteries, veins, and heart, 
 is constantly in motion; this is called the circulation. During 
 this movement, it undergoes constant and regular changes, 
 which, being exactly balanced, preserve it in a medium state of 
 composition. It receives new liquids, prepared by digestion 
 and intestinal absorption; molecules separated from the organs, 
 are unceasingly added to its mass; it is submitted to the action 
 of the atmosphere in the lungs, where it is revivified; it is then 
 sent to all parts of the body, where it undergoes an inverse al- 
 teration, where it furnishes materials that fix themselves in the 
 organs, and where it is deprived of a part of its principles by 
 the secretions. Amid all these changes, none are so striking 
 as those it undergoes in the lungs, where it becomes of a bright 
 red or vermillion, and in the remainder of the body where it 
 assumes a reddish brown colour. These alterations of colour, 
 appear to depend, in the first case, upon an absorption of oxy- 
 gen, and in the second, of carbone. Besides, the nutritive 
 
OF THE FLUIDS. 83 
 
 principle which the blood distributes to all the organs, it is also 
 the vehicle of the warming principle. 
 
 79. The blood varies steadily according to the age, sex, 
 and other circumstances; it also offers accidental changes. 
 
 In the foetus, the blood, which is very dark, has scarcely 
 any coagulable matter. It is the same with the menstrual 
 blood of women. Arterial has a greater proportion of coloured 
 particles than veinous blood. In those individuals that use 
 succulent food, the blood abounds with clot; it is more serous 
 under opposite circumstances. The repeated abstraction of 
 blood, diminishes the proportion of the coloured particles, and 
 even the albumen, but it augments that of the water. 
 
 In disease, the blood suffers changes that have not been suf- 
 ficiently studied. In inflammations, the clot of the extracted 
 blood becomes covered with a white coat, this is the fibrine: 
 and in the clot is also to be seen a large quantity of free colour- 
 ing matter. In particular cases, such as the scurvy, and in 
 septic disorders, the blood loses its coagulability, it remains 
 fluid. There are many diseases on which an attentive exami- 
 nation of the blood would throw great light. 
 
 80. The liquids poured into the blood are the chyle and 
 the lymph. The first comes from the chyme, a grayish, pul- 
 taceous substance, into which the aliments are changed in the 
 stomach, and in which little globules begin to appear. Ab- 
 sorbed by the parietes of the intestine, and having arrived in 
 the first chiliferous vessels, it is whitish and hardly coagula- 
 ble, it becomes more so, and assumes a rosy tint in the glands 
 of the mesentery. Finally, when in the thoracic duct, and 
 ready to pass into the blood, it is distinctly of a rose colour, 
 evidently coagulable, and contains naked globules and parti- 
 cles, which differ from those in the blood, only by an inferior 
 strength of colour. It seems thenceforward to need nothing 
 but the respiratory process to become perfect blood. The 
 lymph, a colourless, viscid, albuminous liquid, but little un- 
 derstood, is the remaining fluid carried to the blood. 
 
 81. The humours which emanate from the blood, are se- 
 parated from it by secretion. We may consider the nutritive 
 matter left by the blood in all the organs, as being of this class; 
 
S4 INTRODUCTION. 
 
 we may also add to it, those which are produced and deposit- 
 ed, as if in reserve (by a secretion that we may call intrinsic.) 
 in the closed cavities of the body, such as fat, serosity, syno- 
 via; but we principally attach to it those which are secreted 
 on the surface of the teguments, external or internal, and of 
 their appendages more or less removed. From their mode of 
 formation, we divide them into three classes or kinds: 1st, in 
 perspiratory humours, which are immediately formed and de- 
 posited on the surface by the vessels: such is the matter of cu- 
 taneous transpiration, of sweat, of the pulmonary perspiration; 
 2d, in the follicular humours, which at first are deposited in 
 the follicles of the skin, internal or external: such are the mu- 
 cus, and the sebaceous matter; and 3d, in glandular humours, 
 formed in the glands, peculiar organs, which have excreting 
 ramifying ducts opening on the skin and mucous membranes, 
 of which they are prolonged ramifications: such are, the saliva, 
 secreted by the salivary glands, the bile secreted by the liver 
 &c. We also divide the secreted humours, from their desti- 
 nation into those which take part in the organism, as the tears, 
 bile, sperm, etc., and into those, which being rejected without 
 answering any purpose whatever, are called, excrementitious. 
 These last are acid, whereas the others are alkaline. 
 
 OF THE ORGANS. 
 
 82. The organs are the solid* or the containing parts of 
 the body; they it is which above all, determine the form of 
 the body, and which direct its motions. 
 
 The figure of the organs is greatly varied : generally speak- 
 ing, however, their contour is rounded; the surfaces are never 
 perfect planes, the lines very straight, or the angles very en- 
 tire. In the generality of them, the length is greater than 
 that of the two other dimensions; some are large and flattened: 
 those that have this form and are soft, are called membranes, 
 whatever, in other respects, may be their texture; others again 
 have but little difference in their three dimensions. We de- 
 termine the external form of the organs by the relation of 
 
 * See Chaussicr. Tublc dcs solides organiques. 
 
OP THE ORGANS. 85 
 
 their three dimensions; we often also, use comparisons more 
 or less trivial: for most commonly it is rather difficult to de- 
 termine the form by a comparison with geometrical figures. 
 
 In the interior, some organs are hollow, and form reservoirs 
 or canals opening externally; others form cavities closed on all 
 sides; a third, ramified and closed canals, a fourth is full or 
 massive : but they are all areolar, and more or less perme- 
 able. 
 
 Among the organs, there are some which extend them- 
 selves, branching or radiating from the centre to the circum- 
 ference: such are the vessels, nerves, and the bones themselves. 
 None i.s insulated, all are interlaced and communicate with 
 each other. Finally, there is a great analogy between the 
 organs, as well as the regions. Some of them being exactly 
 similar, by their union, constitute genera. 
 
 83. The colours of the organs are white, red and brown; 
 some of them are transparent, others opaque. Their consis- 
 tence varies from great softness, to an extreme hardness. 
 They are extensible and retractile, flexible, compressible and 
 elastic, but in very different degrees. The cohesion of some 
 is but slight, while others are endowed with such tenacity as 
 to require very great efforts to break them. These properties 
 of colour and cohesion depend much on the liquids which 
 they in a great measure contain. Thus opaque parts, such as 
 the ligamentous tissue, become transparent by dessication ; 
 this same substance, very tenacious and but little elastic when 
 humid, becomes greatly so when dried ; elastic parts, such as 
 the tissue of the arteries become brittle by dessication, &c. 
 
 84. The organs differ, also, greatly with regard to their 
 texture. At the first glance, we see that several of them are 
 formed by the reunion of bundles of parallel or interwoven 
 threads we then say their texture is fibrous. Others are 
 formed by the union of layers or laminae more or less numer- 
 ous and distinct, and usually, closely united. In others again 
 we find granulations or approximated grains closely united 
 with each other. Some of them have apparently a very com- 
 pact, uniform or homogeneous texture, but it is in appearance 
 
86 INTRODUCTION. 
 
 only; for all are areolar and permeable more or less distinct, 
 all are more or less compound, 
 
 85. This first view of the subject is not sufficient to show 
 the exact texture of the solid parts. By a closer examination, 
 we perceive that these apparent fibres, these membranous layers, 
 these granulations, are themselves compound; and as the solids 
 contain the humours, it has been generally believed, that there 
 is nothing but vessels in the solids. This erroneous idea, for 
 the vessels themselves, are compound parts, has been recently 
 revived in a posthumous work of Mascagni. Other authors 
 have admitted that every thing is formed of the cellular tissue, 
 and this by interwoven layers and fibres, or by cells or vesi- 
 cles adhering to each other. But, the cellular tissue, although 
 it is the principal element of all the parts, is not the only 
 one. As to the idea of a parenchyma, as abase or generating ele- 
 ment of all the solids, it is an extremely vague one, and about 
 which we have not been able to agree. Haller,* besides the 
 cellular tissue formed by the reunion of fibres and layers, and 
 which is the most common and extensive, has admitted in the 
 composition of the organs the muscular fibre and medullary 
 substance. This division, with some slight modifications 
 more or less happy, has been since generally adopted. Thus 
 Walther admits a cellular or membranous texture, a fibrous 
 or vascular one, and a nervous one; Pfaff a vascular structure, 
 a fascicular and a cellular one; others a cellular, a vascular 
 and a massive one, or one without cells and vessels. M. Chaus- 
 sier has added to the three elementary parts of Haller a fourth 
 fibre under the name of albugineous fibre : it is the base of the 
 ligaments; M. Richerand has superadded the epidermoid or 
 horny substance. Among the twenty one tissues admitted by 
 Bichat, there are three which he considers as generators of 
 the others : they are the cellular, the vascular and the nerv- 
 ous. M. Meyert admits, also three elementary organs: 1st, 
 the cell, the vessel or the gland; 2d, the irritable cellular or 
 muscular fibre; 3d, the sensible fibre or the nerve. 
 
 * DC. corporiti huinuni fabrica et fimdianibus. Tom. 1. Lib. 1. sect. iii. 
 f Ueber hutologie, &c. Bonn, 1819. 
 
OF THE ORGANS. 87 
 
 86. In admitting with Haller the existence of three sim- 
 ple organs, of three elementary tissues, or of three distinct 
 fibres, distinguished from each other by essential characters, 
 viz : the cellular tissue, the muscular fibre, and the medullary 
 or nervous substance, we have not even then arrived at the 
 last point that can be attained by anatomical analysis. By the 
 aid of the microscope, we see that these simple organs, with 
 all their modifications and compounds, can be reduced to two 
 anatomical elements. They are formed, of an areolar permea- 
 ble animal substance and of microscopic globules, similar to 
 those found in the humours. The first substance alone forms 
 laminae and most commonly fibres, differing from each other 
 only in the filiform and elongated figure in the first case, widen- 
 ed in the second, and which though sometimes separated, are 
 oftener united : it is from their reunion that result the cells 
 or the areola3, &c. This first element, which by itself, though 
 variously modified, constitutes the greater part of the organs, 
 united with the other, whose particles it assembles and joins, 
 forms the muscular fibre and the nervous substance. 
 
 87. The organs also differ, one from the other, in the phe- 
 nomena they present during life, and which will soon be con- 
 sidered. It will suffice here, to observe, that the cellular 
 substance is particularly remarkable for its continued contrac- 
 tion, which can be augmented by impressions or irritation ; 
 that the ligamentous and elastic tissues, its two principal va- 
 rieties are noted, the one for its great tenacity, and the other 
 for a great elasticity; that the muscular fibre is, by its contrac- 
 tion, the organ of all the great motions and that the nervous 
 substance is distinguished from all others by the faculty of 
 conducting all impressions to the centre, and the action of the 
 nervous centre to the muscles, &c. 
 
 88. The organs differing from each other in their con- 
 formation, their texture, their physical properties, their che- 
 mical composition, and during life in the action they produce, 
 have been divided into a certain number of classes or genera. 
 These genera should be determined from the whole of the 
 characters taken together, and not from the form only j other- 
 
 1 o 
 
88 INTRODUCTION. 
 
 wise we should approximate things of widely different nature^ 
 as all the membranes, and we should separate parts, that with the 
 exception of figure, are precisely alike, as the flat from the 
 long bones, the aponeuroses, from the tendons or ligaments, the 
 nerves from the ganglions, &c.; the fibrous or fasciculated, the 
 lamellated or membranous forms, may belong to parts totally 
 different in all other respects. 
 
 89. The ancients divided the solid parts of the body into 
 similar parts, and dissimilar or organic parts. The similar or 
 homogeneous parts are those which divide themselves into 
 particles similar to each other, as the bones, the cartilages, 
 muscle, tendons, &c. The dissimilar parts are those which 
 are formed by the reunion of similar parts, as the hand, the 
 viscera, the organs of sense, and other compound organs. This 
 idea of Aristotle reproduced with some new developments by 
 Goiter, is the origin and foundation of all the divisions of the 
 organs, subsequently established. The division generally 
 admitted in works of anatomy, of bones, muscles, nerves, 
 vessels and viscera, and some others, is well known. But 
 these genera of organs, comprise compound parts, some of 
 them highly so , and on the other hand these genera, and also 
 all that of the viscera, include organs very different from each 
 other now this deprives us of all the advantages of generali- 
 zation. M. Pinel, in France, and Carmichael Smith,* in 
 England, having drawn the attention of anatomists to the fact 
 that the simple tissues which enter into the composition of 
 dissimilar or compound parts could be separately diseased, 
 and particularly, inflamed, and that their inflammation was the 
 same, whatever was the compound organ of which they made 
 a part, it soon led to a more complete anatomical analysis, 
 than had hitherto been made, especially as regarded the vis- 
 cera. Bichatt developing this prolific idea one worthy of 
 his genius has arranged all the simple organs under the name 
 of tissues or of systems, in twenty one genera. M. Chaussier 
 
 * On inflammation, in Medical Communications, Vol. II. 
 f Anat. generate, appliquee a la physiologic et a la medecine par Xav 
 Bichat. 
 
OF THE ORGANS. 89 
 
 has distinguished the twelve genera of organs, the last com- 
 prising the viscera or compound organs. Since then, several 
 authors, adopting their leading principles, have modified the 
 classifications of the two anatomists.* 
 
 90. In the midst of this variety, the following is a classi- 
 fication or division of the organs in genera, drawn from the 
 ensemble of their anatomical, chemical, physiological and 
 pathological characters. 
 
 The cellular tissue, the principal and general element of or- 
 ganization, should be first; it exists in the whole organic king- 
 dom, enters into all the organs and constitutes the base of all 
 organization. 
 
 This tissue, somewhat modified in its consistence, form, and 
 the proportion of earthy matter it contains, forms several other 
 genera of organs. 
 
 Arranged in membranes, closed on all sides, in whose 
 thickness it has more firmness and less permeability, it con- 
 stitutes the serous and synovial systems. 
 
 It forms the tegumentary tissue, which embraces the skin 
 and mucous membranes, as well as the follicles of these 
 two kinds of membranes, and the organs producing, hairs, 
 teeth, &c. 
 
 It is also the same with the elastic tissue, which is the base 
 of the vascular system, which comprises the arteries, the veins 
 and the lymphatic vessels, and which stilLbelongsto the same 
 order, in approximating to the muscular tissue. 
 
 The glandular system, which is formed by the union of the 
 tegumentary and vascular systems, is also of the same order 
 of organs. 
 
 The ligamentous system comprising very tenacious and re- 
 sisting organs, also results from a modification of the cellular 
 tissue. 
 
 * See almost all the works on anatomy and physiology since 1801, and par- 
 ticularly J. F. Meek el's Handbuch der menschlichcn anatomic, Erster Band. 
 JLllgcmeinc anatomic. Halle and Berlin, 1815. T. Gordon. Ji system of hu- 
 man Anatomy, Vol. I. Edinb. 1815. P. Mascagni. Prodromo della grande 
 anatomia. Fircnze, 1819. C. Meyer. Opuse. cit. 
 
90 INTRODUCTION. 
 
 Finally, the cartilaginous and bony systems belong to the 
 cellular tissue, and owe their solidity to its condensation and 
 the great quantity of earthy salts that.substance contains. 
 
 A second order of organs is formed, essentially, by the 
 muscular fibre: this is, the muscles, whether belonging to the 
 bones, to the external and internal teguments, to the senses, 
 or to the heart. 
 
 The nerves and the central nervous masses, constitute the 
 third and last order of organs, essentially formed by the nerv- 
 ous substance. 
 
 It will be seen that this classification reposes on the basis 
 indicated by Haller, and which truly exist in nature. 
 
 91. The order in which the genera of organs should be 
 arranged, may be founded on various bases: if we paid any 
 attention to the universality, more or less great, of the organs 
 in the series of animals, the cellular tissue should be placed 
 first; after it would come, the tegumentary organs; then the 
 muscles and nerves, the vessels, the glands ; the cartilaginous 
 and bony, the ligamentous and serous tissues would be placed 
 last as peculiar to the vertebrata. Another order would be 
 followed if we were first to class the kinds of organs that be- 
 long to the common or vegetative functions, and next, those 
 which form the apparatus of functions proper to animals. 
 Another order would be established, if, like Bichat we were 
 first to arrange the general systems, as the cellular tissue, the 
 vessels and the nervesj and then the particular systems. It is 
 a matter of but little importance, although it is preferable to 
 arrange the organs from their analogies, as we have done. 
 
 92. Several physiologists, still place the epidermic, or 
 horny substance, among the primitive fibres; but this almost 
 inorganic substance, produced by excretion can not be consi- 
 dered as an anatomical element. The characters assigned to 
 it are the following; it contains no distinct cellulosity; ma- 
 ceration reduces it into a sort of mucilage; chemistry proves 
 that it contains albumen, according to some, and mucus accord- 
 ing to others, not very different things, since mucus appears 
 to be albumen united to soda. This substance is that which 
 
OP THE ORGANS. 91 
 
 constitutes the epidermis, the nails, hairs, and all the horny 
 parts of animals. Although a slight difference appears to exist 
 between the horny and epidermic matters, it is not sufficiently 
 great, to prevent us from referring them to the same sub- 
 stance. M. Meyer, who has recently given a new classifica- 
 tion of the solids of the human body, looks upon the mem- 
 brane of the tympanum, the cornea and crystalline, as being 
 formed of this substance, which he calls the scaly, or lamel- 
 lated tissue; but this approximation has no foundation, parti- 
 cularly the first. The epidermic substances are remarkable 
 for the facility and promptitude of their reproduction. 
 
 93. The names of fibre, tissue, organ, &c., generally 
 designate the organic solids. The meaning attached to them 
 should be more particularly specified. We call tissue, every 
 part that is distinct from another by its texture. The tissue dif- 
 fers from the fibre, only inasmuch as the latter is the finer and 
 composing part of it. A tissue may be formed by fibres that 
 are similar or dissimilar. An organ, generally, results from 
 the reunion of several tissues. These distinctions however, 
 are not absolute: thus the cellular tissue represents at the same 
 time, a particular fibre, a tissue formed by that fibre and an 
 important organ of the animal economy. Generally speaking, 
 the fibre is the element, the tissue indicates the arrangement 
 of parts and the organ, a compound part which has a peculiar 
 action. Almost all the solids are formed by the cellular fibre 
 and its two modifications; some tissues have, for a base, the 
 muscular and nervous fibres ; one alone, which is the tegu- 
 mentary tissue, contains the epidermic substance. The organs 
 are, almost always, parts more or less compound; thus in a 
 muscle we find the muscular fibre, the cellular tissue which 
 surrounds it, and, at the extremity, the tendon to which it is 
 attached; in the same way in a nerve, there is a soft and me- 
 dullary substance in the centre, and externally a particular 
 membrane called the neuralima. Certain parts, such as the 
 stomach, the eye, are still more compound. Generally, every 
 organ or acting part contains cellular tissue, vessels and nerves. 
 The cellular tissue is the most extended: there is no one part 
 where it is not to be found under one form or another. After 
 
92 INTRODUCTION. 
 
 the tissue come the vessels with but very few exceptions, 
 we every where find vessels of different kinds, white or red. 
 The nerves are less abundant than the vessels, and of course, 
 less so than the cellular tissue: the greater number of the or- 
 gans, however, are provided with them. We may, then, 
 regard the organs, as parts into whose composition the cellu- 
 lar tissue constantly enters, vessels almost alwa} r s, and nerv- 
 ous tissue generally. 
 
 The viscera or splanchnic organs take their name from the 
 importance of their offices. They are the organs, the most 
 essential to life; those by which we live ; they are of all the 
 organs the most compound; they are situated in the cavities 
 of the body, called splanchnic. They comprehend the organs 
 of digestion, of generation, and of the urinary secretion, con- 
 tained in the abdomen; of those of circulation and respiration, 
 which are contained in the thorax, and the sensorial and nerv- 
 ous organs, in the cranium and vertebral canal. It is particularly 
 to the thoracic and abdominal organs, and to the latter espe- 
 cially, that is given the name of viscera. 
 
 94. We understand by system or genus, a union of parts 
 of similar texture, such as the bones, the muscles, the liga- 
 ments, &c.: this corresponds to the similar parts of the an- 
 cients. Parts such as the skin, and the cellular tissue extended 
 over the whole body, and thereby presenting regions, and 
 divisions, but not like the preceeding ones, distinct portions, 
 have also been thus designated. Bichat, particularly used the 
 word, system, in this acceptation. The study of the genera 
 of organs, or of the systems constitute the object of general 
 anatomy, which, in this way, embraces every thing that simi- 
 lar parts have in common, and at the same time whatever the 
 generally extended tissues possess in common in the different 
 regions. 
 
 95. The apparatuses are ensembles of organs; sometimes 
 very distinct by their formation, situation, structure and even 
 by their particular action, but which concur in one common 
 end, which is one of the functions of life. It is an error to 
 confound this reunion of parts with that which constitutes a 
 system or a genus of organs. The classification of the appa- 
 
OP THE ORGANS. 93 
 
 rajuses rests entirely on the consideration of the functions, 
 while that of the systems or the genera depends upon the re- 
 semblance of the parts with each other. We have seen as 
 above the enumeration of the genera of the organs; we shall 
 now show how the organs are united in apparatuses of func- 
 tions. 
 
 The bones and their dependencies, viz: the periosteum, the 
 medulla, the greater part of the cartilages, the ligaments, the 
 synovial capsules, constitute & first apparatus of organs which 
 determine the form of the body, which serve as supports for 
 all its parts, and particularly as an envelope to the nervous 
 centres, and which, by the mobility of the articulations, re- 
 ceive and communicate the movements determined by the 
 muscles. 
 
 The muscles, the tendons, the aponeuroses, bursse mucosae, 
 form the apparatus of motion. 
 
 The cartilages and the muscles of the larynx, and various 
 other parts form that of phonatiorf, or of the voice. 
 
 The skin, the other senses, and the muscles which move 
 them, &c. form the apparatus of the sensations. 
 
 The nervous centres and the nerves form that of innerva- 
 tion. 
 
 The alimentary canal, from the mouth to the anus, with all 
 its numerous dependancies, constitute that of digestion. 
 
 The heart and the vessels, that of circulation. 
 
 The lungs, that of respiration. 
 
 The glands, the follicles and the perspiratory surfaces, form 
 the apparatus of the secretions; but the greater part of these 
 organs serving, for other functions, are comprehended in their 
 apparatuses. There remains but the urinary secretions, whose 
 organs alone constitute an apparatus. 
 
 The genital organs constitute a different apparatus in each 
 sex. 
 
 Finally, the ovum, and the foetus it encloses, form a last group 
 or apparatus of organs. 
 
94 INTRODUCTION. 
 
 OP THE ORGANISM. 
 
 96. The human body, during life, presents many pheno- 
 mena of different kinds. In it, as in all bodies, mechanical and 
 chemical actions contantly occur; but they are modified by 
 those of life. There is, in fact, in the human body, as in all 
 such as are organized and living, the essential phenomena of 
 life, viz: nutrition and generation, organic actions, whose ex- 
 ercise is subordinate to other actions proper to animals, viz: 
 the muscular movements and the sensations, subordinate 
 themselves to the innervation. These animal actions are di- 
 rected by the functions of a superior order those of intelli- 
 gence. 
 
 Besides this remarkable order of subordination in the phe- 
 nomena of life, there exists between them a connexion, so 
 that the functions of an inferior kind, also hold in dependance, 
 those of a more elevated one, and that all the functions are in 
 such a state of mutual dependance, that the phenomena of life 
 may be compared to a circle, which once traced, has neither 
 beginning nor end. As has been already stated, it is this en- 
 semble of organic actions that is called organism or life. 
 
 97. We call function,* the action of an organ or of an 
 apparatus of organs having one common end. These functions 
 have been classed or distributed in several genera; not that 
 these divisions are perfectly exact, or that they are very useful 
 as aids to the memory, since the objects classed are by no 
 means numerous; but because in their study it is necessary to 
 follow some order or other, and it is better to follow a natural, 
 than an arbitrary one. The divisions of the ancients, adopted 
 with some slight modifications by Haller,Blumenbach, Chaus- 
 sier, and some other moderns, consist in the arrangement of 
 the functions in four classes : the vital, animal, natural or nu- 
 tritive, and the genital functions. Another division, also 
 taken from the ancients, since the first idea of it, is to be 
 found in Aristotle, which has been pointed out by Bufibn, 
 Grimaud, &c., and which has been adopted and developed by 
 
 * See Chaussier, Table synoptique des f auctions. 
 
OF THE ORGANISM. 95 
 
 JBichal and Richerand, consists in classing the functions in 
 those of the species and in those of the individual, and these 
 latter, in functions of relations or animal functions, and in 
 those of nutrition or organic functions, 
 
 98. The following is a very natural order, in which the 
 functions may be classed. Some are common to all organized 
 bodies, vegetable as well as animal; if not by all their actions, 
 and all their organs, at least by the result. These are the 
 common, organic, or vegetative functions. 1st, nutrition, 
 which comprehends, digestion, absorption, circulation, respi- 
 ration, and the secretions, and whose definite result is the per- 
 petuating the individual in its form, composition, and tempera- 
 ture; 2d, generation, which comprehends the formation of 
 germs, that of the sperm, fecundation, and the development of 
 the fecundated germ, and whose result is the perpetuity of the 
 species, or of a succession of similar individuals. The other 
 functions are proper to animals; they are: 3d, the muscular ac- 
 tion whose results are locomotion, gesture, and voice, and 
 moreover, the muscular movements necessary to the execu- 
 tion of the two preceding functions; 4th, the sensations, and 
 5th, the nervous action or innervation. There is yet another 
 order of functions, belonging exclusively to man, viz. the in- 
 tellectual, which, in other animals, that most resemble him, 
 exists only in appearance. Finally, man not only exercises 
 his individual functions, and those of generation, but, living in 
 society, he exercises collective actions, whose observation and 
 bearing are foreign to physiology and medicine. 
 
 99. While bodies are at rest, we perceive nothing but the 
 qualities by which they strike our senses. While in action or 
 motion, we can still only perceive phenomena, or changes per- 
 ceptible to our senses. Among these qualities and phenomena, 
 some are common to all bodies, others are peculiar to organized 
 and living ones; these last have their peculiar qualities and 
 phenomena, in a word, their properties. Properties, are in 
 fact, nothing else than sensible qualities and phenomena. When 
 the latter reproduce themselves in an order, all of whose con- 
 ditions we can determine, we know the law of such pheno- 
 mena, that is to say, the rule they follow, and to which, it ap- 
 14 
 
96 INTRODUCTION. 
 
 pears to us they are subject: this law when it is general is call- 
 ed theory. Beyond this, we know nothing. But we admit 
 in general, that matter is inert, and every time we see it in 
 motion, we suppose a cause of motion that makes it act, and 
 which we call force. Thus, organic matter being in action 
 during the entire life of organic bodies, we say that life is 
 caused by a vital force.* 
 
 This force has been considered as a different substance from 
 that of the organs, and of which these latter were the instru- 
 ments, at one time it has been considered rational, at another 
 the reverse. It has also been regarded as a faculty proper to 
 matter; either to organic solid matter, or to that which is fluid. 
 It has also been thought to be the result of organization, i. e. 
 of the assemblage of all the solid and liquid parts of an or- 
 ganized body, etc. 
 
 It would, doubtless, have been better in a physical science, 
 like that of the organization of life, had we confined ourselves 
 to the observation of bodies and facts. 
 
 100. The organic or vital phenomena, differing from each 
 other, the vital or organic forces that have been admitted, must 
 consequently be of several kinds. 
 
 There are phenomena of organic formation, such as those of 
 nutrition, generation, the reparation of lesions, reproduction, 
 etc. A force or power of formation, has consequently been 
 admitted under the name of plastic force, formative force,t vi- 
 tal affinity, it is common to all organic bodies, and to all their 
 parts. 
 
 101. The solids of organized bodies, and particularly of 
 animals, receive impressions from various agents, that are im- 
 mediately followed by movements more or less appreciable: 
 these are called movements of irritation, and the force or the 
 cause to which they are attributed, irritability.^ All animal 
 parts are more or less susceptible of it. We notice three prin- 
 cipal varieties of it. In the cellular tissue where it is weak, it 
 
 * See Reil. Von der kbenskraft, in archiv- furv die physiologic. B. I. Halle, 
 1795. Chaussier. Table synoptique de la force vitale, etc. 
 
 f See Blumenbach. Uber dm Bildnngstricb. Getting-. 
 
 * See Gautier. de irritabilitatis notione, natura et morbis. Halx, 1793. 
 
OP THE ORGANISM. 97 
 
 is called tonicity; in the vessels where it is more marked, it is 
 called vascular contractility, and in the muscles where it is 
 greatest, muscular irritability or myotility. 
 
 It is remarkable that all these movements consist in contrac- 
 tions. It has been thought, however, that certain movements 
 depended upon an expansion, an elongation, or a turgescence,* 
 this appears to have been caused by a want of close observa- 
 tion. 
 
 102. In man, and in those animals that have distinct nerves 
 and a nervous centre, the impressions received are transmitted 
 by the nerves, and felt at the centre, and the centres transmit 
 their action to the muscles by the nerves. The cause to which 
 these phenomena are attributed, is called the nervous force, in 
 one word, sensibility. Among the sensations, some are ex- 
 tremely obscure, and but vaguely perceived, t They are pretty 
 nearly every where extended, particularly in the mucous mem- 
 branes. In a state of health, they constitute a general senti- 
 ment of well being; when they are increased by certain causes, 
 they give rise to a morbid sensation called pain. There is no 
 part which may not become the seat of this morbid sensibility. 
 The other sensations are distinct, and some of them altogether 
 special. 
 
 As to the nervous action on the muscles, it directs their ir- 
 ritability; its power is also extended to the vessels, particularly 
 to the smallest. 
 
 Moral and intellectual acts, differ so widely from organic 
 phenomena, that it is impossible they can depend on the same 
 cause; they would in this case be necessary and blind, instead 
 of being enlightened and free. Physiology, which on the one 
 side is met by natural philosophy, here encounters moral phi- 
 losophy or metaphysics. 
 
 103. The functions are not exercised, or if you will, the 
 vital forces do not enter into action spontaneously, but by 
 means of stimulants or exciting causes; whether they be the 
 bodies which act on the external and internal surfaces of the 
 body, or the blood which penetrates all its parts. In relation 
 
 * See Hebenstreit, Jf Turgore v'ltati. Lipsix, 1795. 
 f See Hubner, de Coenxsthesi/ Hal*. 1794. 
 
98 INTRODUCTION. 
 
 to their effects, stimuli differ materially from each other. As 
 to the subjects on which they act, their difference is not less, 
 and depends on age, sex, and above all, on the diversity of the 
 organs, which feel more or less the action of the same agent. 
 Every thing being united in the organization, the action of 
 an organ is not isolated: those which have centres, influence 
 all that are subordinate to them. Others perform their func- 
 tions by association. Some of them to supply the want of it, 
 execute the action which is interrupted in another. There is 
 not a single one of them, which, being extraordinarily excited, 
 by an appropriate stimulus, does not influence more or less the 
 whole organism. 
 
 OF THE DEVELOPMENT AND DIFFERENCES OF THE ORGANIZA- 
 TION. 
 
 104. Each organ, each action, and consequently, the entire 
 organism, presents stadia or degrees of development and per- 
 fection. A first period is that of youth, of a successive growth 
 and perfection, or a second, very short one, is that wherein 
 the organization remains in a state of maturity; a third is that 
 in which the organization is progressively altered, and natural- 
 ly arrives at death and destruction. 
 
 - 105. It is in the beginning of life, that the similitude be- 
 tween the lateral parts is the greatest. The heart is then ver- 
 tical and median, the lobes of the liver nearly equal, the 
 stomach vertical, etc. The upper and lower members are ex- 
 actly alike, at the moment they make their appearance, and for 
 a short time after. The genital organs of both sexes are at first 
 similar. It is also in the commencement of life that animals 
 bear the strongest resemblance to each other. The relative 
 size of the parts changes with age: thus the nervous system, 
 the senses, the heart, the liver the kidneys etc, are at first 
 large, in comparison with the rest of the body, while on the 
 contrary, the intestine, the spleen, genital organs, lungs, mem- 
 bers, etc, are very small as regards the rest of the body, and 
 the other organs. This added to the fact, that certain parts 
 disappear, or greatly diminish with age, constitutes a species 
 
DEVELOPMENT, ETC. OF ORGANIZATION. 99 
 
 of metamorphosis; thus the membranes of the ovum and the 
 placenta, the pupillary membrane, the milk teeth cease to ex- 
 ist, and the surrenal capsules and the thymus gland, greatly 
 diminish, and finally, almost totally disappear. 
 
 106. The organs and humours are not always in the same 
 proportion. In the beginning the embryo is nothing but a 
 nearly liquid molecule ; in time the proportion of solids in- 
 creases and continues to augment till the end. The colour is 
 also gradually developed; at first all the parts are white, the 
 colouring of the blood and other parts takes place, by degrees. 
 There is at first no determined texture in the organs: there is 
 even no globules in the beginning, while at a later period, the 
 whole mass of the body appears, globular, or granulated, after 
 which fibres, lamina and vessels become distinct. All the 
 organs are not developed at one time. Even those of the 
 same genus or system are not all formed together. The ex- 
 ternal form or configuration is drawn before the consistence, 
 texture and composition are fixed; for, as we see in the fruit 
 of the almond which has already its form, and is as yet a mere 
 glairy liquid which will successively acquire the consistence, 
 texure and composition proper to it, so the nervous and bony 
 systems already have partly their form while yet liquid. The 
 cellular tissue; and the vessels permeable by liquids, diminish 
 from the beginning to the end of life; it is, above all, this 
 change which continues after the end of the growth, that essen- 
 tially appears to constitute the period of the deterioration of 
 the organism and of old age. 
 
 107. The organs are formed by separate parts that after- 
 wards unite; thus the nervous medulla is at first a double 
 cord ; the intestine and the cavity of the trunk, at first open 
 in front, afterwards close it is also the same with the spinal 
 canal. The vessels, at first, are isolated vesicles which stretch 
 and communicate in the mass of the body : the kidneys, at first 
 multiple, coalesce and adhere; the bones which in the carti- 
 lagenious state, lengthen themselves by a species of vegeta- 
 tion, afterwards become ossified in separate parts which then 
 unite, &c. Traces of this formation, remain in certain places, 
 stronger in some, weaker in others; thus the raphe of the skin, 
 
100 INTRODUCTION. 
 
 the middle suture of the os frontis, the median line of the 
 uterus, &c. are sufficiently apparent marks of a reunion of the 
 two halves; on the contrary, in the superior portion of the ster- 
 num, in the body of the vertebra, these traces, are, generally, 
 completely effaced. 
 
 108. All the phases through which the human organism 
 passes, correspond with permanent states or conditions in the 
 animal kingdom. We could here accumulate the proofs of 
 this important proposition by drawing a parallel between the 
 human foetus in its various stages of development and the de- 
 grees of organization of the animal scale. Some few exam- 
 ples, however, will suffice. The embryo is at first a mere bud 
 or germ, placed on a vesicle, such, are some of the most sim- 
 ple worms. At a more advanced epoch, it is a little vermiform 
 body without distinct members or head; this is the case with 
 the annelides; still later, the members are equal and the tail 
 protrudes: such is the fact with respect to the greater portion 
 of quadrupeds. In the nervous system, we first see the nerves 
 with their ganglions: such is the case with all the inverte- 
 brata provided with nerves; at a later period we can distin- 
 guish the vertebral and cranial medulla, the tubercles of the 
 latter, and as yet only the rudiments of a cerebrum and cere- 
 bellum : this is the case with fishes and reptiles; still later 
 these last parts increase much more than the tubercles and the 
 encephalon is successively that of birds and the mammalia, 
 until, finally, by the predominance of the cerebral and cere- 
 bellous lobes, it becomes that of man himself. We should see 
 in following the development of the bones, that they are at 
 first mucilaginous, then cartilaginous, afterwards bony and in 
 this state, separated in pieces, which are afterwards welded 
 together; in comparing this development with the state of 
 the bony system in the lamprey, in the cartilaginous fishes 
 and in the oviparous vertebrata in general, we should have 
 another proof of the proposition advanced. It would be the 
 same if we were to pass in review all the genera and all the ap- 
 paratuses of organs. 
 
 109. Man is distinguished from all other animals by the 
 great rapidity with which he passes through the first epochs 
 
DEVELOPMENT, ETC. OF ORGANIZATION. 101 
 
 of his formation or of his development; consequently, it is 
 also difficult to perceive in him these first changes. The 
 comparison of man with animals, and of man with himself at 
 different ages, is a point of comparative anatomy, which al- 
 ready rich in a great number of facts, recommends itself by 
 its importance to the observation of the accoucheur. , 
 
 110. As may easily be imagined, the organic phenomena 
 follow the successive development of the organs. In the 
 embryo, there is only an almost direct absorption and assimu- 
 lation of the nutritive matter; afterwards the vessels become 
 apparent, and it is the circulation which then, every where dis- 
 tributes the materials of nutrition; the secretions then begin 
 to form, and the blood of the foetus, brought into contact with 
 that of the mother through the medium of the placenta, de- 
 rives from it a kind of branchial respiration. At birth, atmos- 
 pheric respiration and digestion are added to the other nutri- 
 tive functions, and the animal functions enter into exercise; 
 and here, as in the whole animal kingdom, we see the organs 
 and their functions the last developed, hold all the rest in a 
 state of dependence, and life to result from the connexion of 
 organic actions with each other. 
 
 111. The organization of man presents differences in the 
 sexes:* besides those that exist in the organs of generation, 
 there are others in the general form of the body and in the 
 proportion of its parts. Man is generally larger than woman; 
 the total weight of his body is about one third greater. The 
 contour is more rounded in woman, bolder and more salient 
 in man; the trunk of woman is shorter, and the inferior ex- 
 tremities longer, so that the middle of her body is lower in 
 her, than in man the abdomen, and the pelvis particularly, 
 are larger in proportion than the shoulders and chest, which 
 is short, and tapering. The organs contained in the abdomen, 
 are larger, and those of the breast and neck smaller, in pro- 
 portion to the rest of the body, in woman than in man; the 
 bones and the muscles are less developed, the adipose tissue 
 
 * Sec J. F. Ackerman, de discrimine sexuum prscfer gemtalia. Mogunt, 
 1787. Ejusd. historia etichnogr. infantis androgyniJente, 1805. 
 
102 INTRODUCTION. 
 
 more so; the general texture of the parts is softer and more 
 lax; the hairs weaker and less numerous. As to the genital 
 organs, the very great differences they present, do not destroy 
 their essential analogy. The external characters of the sexes 
 we have just indicated, appear to depend upon the existence 
 and action of the ovary in woman and of the testicle in man. 
 In the embryo, where the sex is doubtful, there are no exter- 
 nal appreciable differences; in the foetus and infant they begin 
 to show themselves in proportion as the genital organs are 
 developed: in puberty the sexual characters are most perfect, 
 in old age they become less so. The want of a complete de- 
 velopment of the ovaries or testicles, their changes by disease, 
 and their ablation, likewise prevent the general differences of 
 the sexes from establishing themselves, or efface them more 
 or less completely. The causes of the difference between the 
 sexes has been sought for in a supposed predominance of the 
 coagulating principal, or of oxygen in the male and of the nu- 
 tritive matter in the female. 
 
 112. The human species presents differences of organiza- 
 tion, hereditary in the races or varieties,* scattered over the 
 globe, and that may be considered five in number, and of 
 which there are three principal ones, viz: the Caucasian, the 
 Mongol and the Ethiopian, and the Malay and American 
 races. 
 
 113. The Caucasian, to which we belong, is remarkable 
 for the beauty of the form and the proportions of the head, in 
 which the cranium is much larger than the face; a fact of 
 which any one will be convinced by simple inspection, as well 
 as by the application of cephalometers. The cranium is high 
 and rounded, the face is oval and its parts but slightly salient. 
 The colour of the skin is generally white and rosy; that of 
 the eyes blue or brown, that of the hair, which is generally 
 abundant, fine and long, varies from white to black. 
 
 The Caucasian is peculiarly remarkable for the development 
 of his intelligence, for civilization and the culture of philoso- 
 
 * See Blumenbach, op, cit- Lawrence, op. cit. 
 
DEVELOPMENT ETC. OF ORGANIZATION. 103 
 
 phy, the sciences and the arts. The coloured races on the 
 contrary have the senses in greater perfection. 
 
 114. The mongol is recognised by the strength of the 
 trunk, the smallness of the members, the almost square form 
 of the head, and the obliquity of the forehead, by the breadth 
 and flattening of the face, the projection of the cheek bones, 
 and by the separation, narrowness, and obliquity of the eyes; 
 the skin is olive; the hair is straight, black and short; the beard 
 scanty, and sometimes totally wanting. 
 
 115. The negro has the trunk slender, particularly at the 
 loins and pelvis; the superior members are long, particularly 
 the fore-arm; the hands are small, the feet large and flattened; 
 the knee and foot are turned outwards; the head is narrow and 
 elongated; the inferior part of the face projects; the nose is 
 flattened ; the anterior teeth are oblique, and the lips salient ; 
 the skin, the iris and the hair, are black ; the latter is crisped, 
 and the beard thin. 
 
 116. The anatomical characters of the American race are 
 less defined, and seem intermediate between the Caucasian and 
 the negro. The skin is of a copperish red ; the hair is black, 
 straight and fine, and the beard scanty or wanting. 
 
 117. The malay is like the American, but little distin- 
 guished by characters drawn from anatomy, he appears to be 
 between the two first. In this race, the skin is brown or 
 tanned, and the hair thick and curly. 
 
 118. Fabulous varieties have also been admitted: this is 
 no place to speak of them. Albinos originate from a morbid 
 change. In each race we also find sub-varieties more or less 
 marked. In different countries, often nearly approximated, we 
 generally observe a national character, at least, as regards the 
 physiognomy; but in each race also, in each nation, and even 
 in much more limited divisions, we sometimes find individuals 
 very different from others; thus it is by no means very 
 rare, that we find in the negro, all the anatomical and phy- 
 siological characters of the Caucasian race, colour excepted, 
 and vice versa. The varieties, otherwise, are confounded by 
 insensible gradations. We must then consider these varieties 
 in the species, as accidental differences only, the causes of 
 15 
 
104 INTRODUCTION. 
 
 which, it is true, are not easy to determine, but how confined 
 also, are the observations made on such a subject, and conse- 
 quently how unequal to the determining of the conditions of a 
 phenomenon for the production of which nature has spared no 
 time. 
 
 OP THE ALTERATIONS OF THE ORGANIZATION. 
 
 119. The human body does not always arrive at the term 
 of its existence by a progressive alteration of the organization. 
 Most generally the development stops, deviates from the usual 
 course, or the organization regularly developed, becomes al- 
 tered by the action of external agents. The body thus altered 
 in its conformation, in its texture, in its composition, is the sub- 
 ject of morbid anatomy. To the physician, this kind of anato- 
 my is the necessary compliment of the anatomy of the healthy 
 body; it is to pathology, what ordinary anatomy is to phy- 
 siology; pathology can no more exist without morbid anato- 
 my, than physiology without anatomy; there can no more be 
 morbid phenomena or symptoms without altered organs, than 
 functions without regular organs, than phenomena without bo- 
 dies, motion without matter. Morbid anatomy is the founda- 
 tion of pathology. 
 
 120. The derangements of the organization, may affect the 
 conformation of the body, in general, or of some organs: this 
 constitutes a first class, that of vices of conformation. Some 
 are original or primitive, others are secondary or acquired. 
 These latter are numerous and very different from each other. 
 As to the first, attentive observation has caused the discovery 
 of one of the most important laws of the development of the 
 organization. These vices, are in fact, and essentially, only a 
 permanent state, in one or several organs, stadia or degrees, 
 through which they pass in the progressive development. 
 Thus, for instance, the numerous vices which consist in a fis- 
 sure or separation, more or less great, on the median line, as 
 the hair-lip, that of the roof of the mouth, or of the velum pa- 
 lati, the opening of the sternum, of the diaphragm, of the wall 
 of the abdomen, of the anterior parietes of the bladder, of the 
 
ALTERATIONS OP THE ORGANIZATION. 105 
 
 pubis, of the urethra, of the perineum, spina bifida, cranium 
 bifidum, etc. are merely the permanent state of a fissure, which 
 should only be temporary. 
 
 The junction of the fingers, the prolongation of the coccyx, 
 the persistence of the pupillary membrane, the bifid uterus, the 
 testicle in the abdpmen, etc, are merely, situations, divisions, 
 reunions, states of continuance of organs, which ought only to be 
 temporary, and which have remained permanent. It is the same 
 with the anormal communications of the cavities of the heart, 
 of the opening of the bladder at the umbilicus, of the existence 
 of a cloaca and congenital umbilical hernia. 
 
 Sometimes, it happens, that when one of these vices exists, 
 the rest of the organization is developed, nearly, as usual; but 
 in certain cases, one imperfection is the unavoidable cause of 
 others, and here is one of the most striking examples; if the 
 olfactory nerve and ethmoidal bone which contain it, are ar- 
 rested in their development, the orbits and the eyes will be- 
 come more or less intimately confounded, and will constitute 
 what is called a cyclops. * It is the same with respect to seve- 
 ral others. 
 
 This part of pathological antomy, which has been regarded 
 as a mere matter of curiosity, is on the contrary, of great in- 
 terest to the physiologist, and the pathologist. 
 
 121. The derangements of the organization, may also consist 
 in an alteration of the texture, and composition of the organs. 
 The following are the effects and productions of irritation, 
 of inflammation, and of other less known derangements of the 
 secretions, and of nutrition: adhesion, generally, and the dif- 
 ferences it presents in the various divided organs; pus and 
 other liquid products of inflammation; transformations of one 
 tissue into another resembling healthy tissues; the degenera- 
 tion or the changing of an organ into a substance that has no 
 analogy with anything in the regular organization; the hard 
 or soft concretions which are formed in the ducts and reser- 
 voirs of follicles and glands, and which are owing to an altera- 
 tion in the liqui'd secreted, and in the secretory organ, are so 
 
 * See Beclard. Memoir es sur les foetus acfyhales. 
 
106 INTRODUCTION. 
 
 many highly important genera of this class, the study of which, 
 is of no doubtful use, as may appear that of the vices of con- 
 formation. 
 
 We must add to these two classes, that of intestinal worms 
 sufficiently numerous, and that of the parasitic animals which 
 may exist in man. 
 
 OF DEATH AND THE CADAVER.* 
 
 122. Deatht is the final and total cessation of the functions 
 of life, soon followed by the dissolution of the body. It is the 
 necessary and inevitable result of the successive changes of the 
 organism. It is seldom, however, the last term of life arrived 
 to extreme old age; most generally it is occasioned by acci- 
 dental causes. 
 
 Life consists, essentially, in the reciprocal action of the cir- 
 culation of the blood, and of inner vation, death always results 
 from the cessation of this action. Senile death, appears to re- 
 sult from the simultaneous weakening of these two functions, 
 and the simultaneous alteration of their organs, and morbid or 
 accidental death from the primitive alteration of one of the 
 two organs, and of its function. It is always, in fact, by the 
 interruption of the nervous action upon the organs of the cir- 
 culation, or by the cessation of the action of the blood on the 
 nervous centre, that death is determined by accident or disease. 
 But the blood may cease to'act upon the nervous system, so as 
 to continue life; either because the heart no longer sends it 
 there, and that the vessels cease to conduct it effectually; or 
 because the blood is no longer submitted to respiration; or be- 
 cause it is not purified by the secretions from noxious princi- 
 ples, by the urinary depuration in particular; or because the 
 intestinal digestion and absorption do not furnish it with nu- 
 tritious materials; or, finally, because deleterious substances 
 are car/ied into the mass of this fluid from without. 
 
 123. The cadavert is a dead, organized body; but this 
 
 * We prefer this word, although not English, to any paraphrase. The 
 cadaver, is the body after the extinction of life. TRANS. 
 
 f See Chaussier. Table des phenomtnes cadaveriques. 
 
OP DEATH AND THE CADAVER. 107 
 
 term is particularly applied to an animal, and chiefly to man, 
 who has ceased to live. The body, in which the vital action 
 is insensible, soon looses its heat and mobility. For a few 
 moments after, we may observe in it some particular pheno- 
 mena the last vestiges of that life which has just ended, and 
 which are called primitive cadaveric symptoms. But the ca- 
 daver has an ephemeral duration only. Putrefaction always 
 commences after a certain and generally, very short time, 
 unless under peculiar circumstances; its elements separate, 
 and the bones alone remain for a while, to be destroyed 
 in their turn. Although all dead bodies are disposed to 
 the changes of which we are speaking, all do not alter in 
 the same space of time, or in the same manner. The age and 
 constitution of the individual, the proportion of his humours, 
 the nature of his death, the circumstances which have pro- 
 ceeded it, the season, climate, state of the atmosphere, the 
 bodies which surround the corpse, &c., are all so many cir- 
 cumstances, each of which has an influence, sui generis, upon 
 the development of cadaverous phenomena; besides this, each 
 organ undergoes peculiar changes. The following are the most 
 general alterations that ensue: 
 
 124. The warmth, as well as the other phenomena of nutri- 
 tion, sometimes diminishes immediately previous to death, 
 and ceases altogether shortly after. The cooling takes place 
 gradually and commences at the surfaces and extremities. It 
 proceeds so much the faster, as the subject is the more ex- 
 hausted by old age or disease, deprived of blood, lean, and the 
 atmosphere more cold; under these circumstances it may be 
 effected in two or three hours, whereas it generally requires 
 fifteen or twenty hours; it may even require several days. 
 The blood is blackish, and generally preserves its fluidity and 
 motion while the body is warm; the aorta and principal arte- 
 ries are emptied: it accumulates most commonly in the vena 
 cava, in the auricles of the heart, the vessels of the lungs and 
 even in the veins generally, a circumstance resulting from the 
 elasticity of the arteries and bronchia? and from the mechan- 
 ism of the chest. The accumulation of blood in the veins 
 varies according to the causes of death; where there has been 
 
108 INTRODUCTION. 
 
 dyspnea or suffocation, it is very considerable, and in this case, 
 there are sometimes congestions, turgenscenscies, erections, 
 and even sanguineous transudations. The blood, obeying its 
 gravity and the action of the arteries, accumulates and forms 
 livid spots in those parts that are dependent at the moment of 
 death, and while the body is yet warm, the rest of it remain- 
 ing pale and yellowish. During all this period of cooling, 
 the body is in general soft and flexible, the eyes half open, the 
 lower lip and jaw pendent, the pupil dilated: congestions that 
 have existed during life, sometimes disappear; the sphincters 
 are relaxed, and sometimes, through a remaining vestige of 
 contractibility, an expulsion of the faeces takes place, and 
 even parturition. The muscles may yet be irritated by vari- 
 ous stimuli, by galvanism particularly. 
 
 125. The soft parts remain flexible and the blood fluid, as 
 long as the body preserves its warmth; no sooner has that 
 abandoned it, than the blood coagulates, and the soft parts 
 become stiffened in a greater or less degree. The coagulation 
 of the blood varies greatly; generally it is either white or le- 
 mon coloured concretions, which are moulded in the vessels; 
 sometimes the blood assumes the consistence of jelly, or even 
 remains completely fluid. The cadaverous stiffness is a con- 
 stant phenomenon, and is characterized by the firmness of the 
 soft parts and the resistence and immobility of the articula- 
 tions. It begins in the trunk and extends first to the superior, 
 and then to the inferior extremities. This phenomenon which 
 appears to depend, essentially, on the last contraction of the 
 muscles, and also on the general cooling and coagulation of 
 the fluids, presents a great difference as regards the moment 
 of its manifestation, its intensity and its duration. Thus in 
 death from old age, in that induced by a slow exhaustion or 
 by excessive fatigue, from gangrenous, putrid, or scorbutic 
 diseases, &c. , the stiffness ensues very promptly, is not very 
 intense, and scarcely lasts for one or two hours. On the con- 
 trary in strong, muscular subjects, who expire suddenly by 
 violence; after most asphyxies and acute diseases, the stiffness 
 does not come on for twenty or thirty hours, becomes very 
 considerable and remains for three or four days. The rigidity 
 
OF DEATH AND THE CADAVER. 109 
 
 of the soft parts, afterward spontaneously ceases, and in the 
 same order of its manifestation; it is replaced by a softness 
 that gradually augments; the parts are abandoned to their 
 gravity, take a consequent direction and sink. The coagu- 
 lated fluids become again liquified, and their fluidity even 
 seems to increase. Such are the first phenomena of putrid 
 decomposition. 
 
 126. In some cases and most commonly after a sudden 
 and violent death, there is a considerable and rapid disen- 
 gagement of gas, either in the intestinal canal, the serous cavi- 
 ties, the cellular tissue or even in the vessels themselves: from 
 this result other various remarkable phenomena. The tym- 
 panites of the abdomen pushing up the diaphram, freqently 
 occasions a discharge of mucus from the mouth or nares, and 
 sends the blood to the neck and head: whence, the swelling 
 of the face, the lustre of the eye, the contraction of the pupil; 
 it also causes a reflux of the matter in the stomach to the 
 pharynx, larynx, the nasal fossa or the mouth; it also occa- 
 sions a determination of blood to the genitals, the excretion of 
 gas, of faeces, and sometimes, even a rupture of the abdominal 
 parietes. The development of gas in the cellular tissue con- 
 stitutes the cadaverous emphysema; its disengagement in the 
 heart and vessels occasions a motion in the blood and even 
 its flow from wounds, phenomena styled, cadaverous cruen- 
 tation. 
 
 127. Putrefaction is an intestinal movement, the inverse 
 of the organic action, which establishes itself in the body, de- 
 stroys all the combinations, which were formed by the vital 
 action, separates their molecules, reduces them to a simpler 
 state of composition, reduces them to gas, vapours, putres- 
 cence and earth, and thus restoring them to the general mass 
 of inert bodies. Besides the cessation of life, putrefaction re- 
 quires as other requisites, the contact of air, and a certain de- 
 gree of heat and humidity. The extent and combination of 
 these requisites, occasion much variety in the phenomena of 
 decomposition. 
 
 128. It commences commonly, the instant the coagula- 
 tion and rigidity cease: from that moment the liquids begin 
 
110 INTRODUCTION. 
 
 to be resolved, and the soft parts, gradually, to soften and re- 
 lax. The body, which exhales from the beginning a vapour, 
 whose loss diminishes its weight, then gives out a stale and 
 musly odour. The blood and other humours transude from 
 their reservoirs, and impregnate the surrounding parietes and 
 parts with their colour and odour: thence the colouring of the 
 veins and surrounding cellular tissue which is red, the spots 
 printed on the stomach and the intestines, by the liver, the 
 spleen and gall-bladder, the sero-sanguineous infiltrations in 
 the cellular tissue and serous membranes, their rose, red and 
 brown colours, and the tinging of the abdomenal parietes with 
 a bluish or greenish tint. The humours of the eyes transude, 
 whence the destruction of the cornea and by mingling with 
 the corpuscules that flit about in the eye, they form a slimy 
 coat or covering. 
 
 In this first period, the muscles redden litmus paper. 
 
 129. Putrefaction, which, as respects the regions, gene- 
 rally commences in the abdomen, on account, of theexcremen- 
 titial matter there accumulated; which, as respects the organs, 
 begins in the softest and such as are the most impregnated 
 with fluids, as the encephalic mass, and which also first attacks 
 engorged parts, or such as have been altered by disease or the 
 kind of death, soon becomes general. The epidermis is de- 
 tached, and raised by masses of a brownish sanies; the muscles 
 by the imbibition of the fluids become glutinous, greenish, 
 pulpy and ammoniacal; a putrid and nauseating odour is dis- 
 engaged. 
 
 130. Finally the texture disappears in toto; the soft parts, 
 confounded with the fluids are reduced into a half fluid pu- 
 trescence, mixed with bubbles of gas, exhaling the most infec- 
 tious odour, and the most pernicious vapour. Soon, nought 
 remains but the bones, which in their turn become friable and 
 pulverulent, leaving nothing but a small earthy residuum. 
 
 131. When the conditions of putrefaction are favourable, 
 as after certain diseases and in hot and humid times and places, 
 it commences at the moment of death, and runs through its 
 stages with the greatest rapidity. Under contrary circum- 
 stances it is slow, and may be completed only after the lapse 
 
OF DEATH AND OF THE CADAVER. Ill 
 
 of years. It may be even indefinitely suspended, or its phe- 
 nomena much modified. Thus a body enclosed by ice, may 
 be preserved without undergoing any sensible change, as long 
 as the congelation lasts: thus also, a body dessicated by a dry 
 and hot atmosphere, like that of the deserts of Africa, or by an 
 absorbent earth, as in certain caves, or by the heat of the oven 
 or stove, or by various chemical operations, may become near- 
 ly imputrescent. In like manner, a body plunged into the wa- 
 ter and kept there, in humid earth, or in one saturated with 
 cadaverous products, may be transformed into adipocire, be- 
 come saponified by the reciprocal action of its fat, and the am- 
 monia, which results from the decomposition of the flesh. 
 
 132. The body, for some time after death, still preserving 
 nearly the same organization and composition as when alive, 
 is the subject on which anatomy is studied. As numerous 
 changes, however, which continue to augment, commence 
 from the moment of death, we must, by the examination of 
 living animals, rectify the ideas we have acquired by that of 
 bodies deprived of life. 
 
 Every subject is not equally fit and proper for the study of 
 anatomy. For long and consecutive dissections, we should not 
 select those which have yielded to putrid diseases, or fatigue, 
 those that are still warm, or those in which putrefaction has 
 been rapid or is much advanced: extreme cleanliness is abso- 
 lutely necessary in all anatomical researches. If a wound is 
 received while dissecting, particularly if the subject be not a 
 proper one, it should be washed and cauterized on the spot. 
 
 133. The anatomist, considers in each solid part of the bo- 
 dy, 1st, its configuration or its form, external as well as in- 
 ternal, if it is hollow, and its position, whether symmetrical or 
 irregular; 2d, its situation in the whole body, and relative to 
 other parts, as well as its relations of contact or connexion, 
 more or less intimate with them; 3d, the direction of its great 
 diameter which may be parallel, oblique, or perpendicular to 
 the axis of the body ; its metrical extent either as relates to the 
 body or some of its parts ; 5th, its physical proportions, either 
 as relative to the attraction of its molecules, as its density, its 
 
 cohesion, elasticity, &c. or as relates to the manner in which it 
 16 
 
112 INTRODUCTION. 
 
 is affected by light, as its colour and transparency ; 6th, its ana- 
 tomical composition and its texture, or the arrangement of its 
 integral parts; 7th, its properties and chemical composition; 
 8th, the liquids or humours it contains ; 9th, the properties it 
 enjoyed during life ; 10th, its vital actions, and the connexion 
 of this action with the others; llth, the varieties it presents in 
 the ages, sexes, races, and individuals ; 12th, its morbid states, 
 and 13th, its cadaverous phenomena and changes. Although 
 several of these considerations seem to belong to the study of 
 natural philosophy, chemistry, physiology, and pathology, ra- 
 ther than anatomy, there is none of them that will not en- 
 lighten the anatomist, not one of them that he should neglect. 
 
GENERAL ANATOMY. 
 
 CHAPTER I. 
 
 OP THE CELLULAR AND ADIPOSE TISSUES. 
 
 134. These two tissues have been generally confounded 
 under the name of cellular tissue; they are, however, very dif- 
 ferent, and should be separately described. 
 
 SECTION I. 
 
 OF THE CELLULAR TISSUE. 
 
 135. The cellular tissue, has been so called, on account of 
 the areolae it forms, improperly, perhaps, styled cells. It is a 
 soft spongy tissue, extending through the whole body, sur- 
 rounding all the organs, uniting them, and at the same time 
 separating them from each other; it penetrates into their sub- 
 stance, and has the same mode of existence with all their parts ; 
 entering into the composition of all organized bodies, and of all 
 organs, it is the principal element of organization. 
 
 According to the light in which it has been viewed, the dif- 
 ferent names of substance, body, system, organ, membrane, 
 cribrous, mucous, glutinous, intermediate, areolar, reticulated, 
 laminous, filamentous tissue, &c. have been given to it. The 
 name of cellular tissue is perhaps no better than the others; it 
 is, however, more generally adopted. 
 
 136. Notwithstanding the very great extent and import- 
 ance of this tissue, which must have arrested the attention of 
 anatomists, at an early period, no description of it is to be 
 found in ancient authors. Hippocrates, speaks of the gener 
 ral permeability of the tissues, when he says, that the whole 
 
114 GENERAL ANATOMY. 
 
 body perspires without, as well as within: the first ideas of the 
 existence of the cellular tissue, have been sought for in this 
 passage. What Erasistratus called parenchyma, corresponds, 
 perhaps, with this tissue. But we find no exact ideas, as to its 
 disposition, until the time of Charles Etienne, Vesalius, and 
 Adrian Spigel : even these anatomists, and a great many of 
 those who succeeded them, have only indicated the cellular 
 tissue, in the different places where it is met with, as around 
 the vessels, muscles, fat, &c. Kaaw Boerhaave, Bergen and 
 Winslow, were the first who published some general ideas, on 
 the continuity of this tissue, in the different regions; but it is 
 since the time of Haller, only, that it has been presented to us 
 in a correct point of view. The cellular tissue has occasioned 
 many treatises. Schobinger, Thierry, W. Hunter, Bordeu, 
 Fouquet, Wolff, Detten, Luca3, de Felici, paid particular at- 
 tention to it. Their works have added but little to the de- 
 scription given by Haller ; but several of them are remarka- 
 ble* for ideas, more or less correct, of the nature and func- 
 tions of this tissue. All anatomists, and those in particular, 
 who occupied themselves with general anatomy, have spoken 
 of it in their books: Mascagni, alone, scarcely names it. There 
 are no good plates of the cellular tissue, in fact, having no de- 
 termined form or colour, it is impossible to represent it; 
 Wolff has made the experiment, but has failed. 
 
 137. In order to facilitate the study of the cellular tissue, 
 we examine it successively, in two portions, of which one is 
 considered as independent of the organs, and as merely filling 
 
 *Dav. Ch. Schobinger. De telsc cellulosae, in fobrica corporis humani,- dig- 
 nitate. Gott. 1748. Fr. Thierry. Ergo in celluloso textu frequentius morbi et 
 morborum mutationes. Paris. 1749, 1757, 1788. W. Hunter. Remarks on 
 the cellular membrane, etc, in Med. Obs. and Inq. vsl. II. London 1757. Th. 
 de Bordeu Rccherches sur le tissu muqueux ou Porgane cellulaire, etc. Paris 
 1767. Fouquet and Abadie. De corpore criboso Hippocratis. Monsp. 1774 
 C. F. Wolf. De tela quam dicunt cdlulosam observationes, in nova act a Jicad. 
 Sc. Imp. Pctrop. vol. vi, vii, viii, 1790, 1791 M. Uetten. Beytrag etc. viz. 
 supplement to the study of the functions of the cellular tissue. Munster, 
 1800. S. H. Lucre, .ftnnotationes circa telam cellulosam, in obs. circa nemos, 
 etc. Franc, ad Moen. 1810. G. M. de Felici. Cennl di una nuova idea, sulla 
 natura del tcssuto cellulare. Pavia, 1817. 
 
OP THE CELLULAR TISSUE. 115 
 
 the spaces between them, while the other relates only to the 
 organs it envelops and inlo whose texture it enters. These 
 portions or divisions are distinct, in imagination only, for the 
 cellular tissue is every where continuous with itself. 
 
 137. The first portion is the external, general or common 
 cellular tissue textus cellular is inter medius,seu laxus that 
 which does not penetrate into the organs. This common cel- 
 lular tissue has the general extent and form of the body; if we 
 could suppose all other organs to be removed, and that this 
 tissue could support itself, it would form a whole, preserving 
 the form of the body and presenting a number of cells or ca- 
 vities for the different organs. The thickness of the layer it 
 forms round each of the latter, is not every where the same. In 
 the vertebral canal the cellular tissue is but in a very small 
 quantity; in the interior of the cranium, it forms an almost 
 invisible layer, so great is its tenacity. More of it is found on 
 the exterior of these same parts: it is particularly abundant 
 about the spine, in front, especially. The different parts of 
 the face, the orbits, the cheeks, contain a large quantity. 
 There is also a great deal in the neck, along the vessels and 
 between the muscles, in the thorax between the layers of the 
 mediastinum, and on the exterior of this cavity round the 
 mammae. A great quantity of cellular tissue is contained in 
 the abdomen, both in its interior, and in the thickness of its 
 parietes. This tissue abounds in the groin, axilla, among the 
 hamstrings, in the palm of the hand and the sole of the foot; 
 between the muscles it forms layers, more or less thick. Gene- 
 rally speaking, it is the more importantorgans that are most sur- 
 rounded by the cellular tissue; this tissue is also most plenty 
 in those places that are the seats of great motions. Besides as 
 it envelops all the organs and every where forms the parti- 
 tions that divide them, other circumstances being equal, there 
 should be most of it wherever these organs are most numer- 
 ous: accordingly, this is what we find, in the neck. 
 
 139. The continuity of the cellular tissue is particularly 
 apparent in the great spaces between the organs. In the neck, 
 the continuity of this tissue with that of the head above, and 
 
116 GENERAL ANATOMY. 
 
 with that of the interior of the thorax below, is evident: the 
 openings of this cavity which communicate with the superior 
 members, present an equally well marked continuity of the 
 cellular tissue of the chest with that of the superior members. 
 In a similar way in the abdomen, the ischiatic notch, the in- 
 guinal ring, the crural arch, &c. present, an evident continui- 
 ty of the cellular tissue within the abdomen and without, and 
 hence with the inferior members. The intervertebral foramina 
 along the vertebral canal, establish a communication between 
 the interior and exterior of the canal; the foramina at the base of 
 the cranium establish in like manner a communication between 
 its cavity and the outside of the head. The continuity of the 
 cellular membrane does not only exist in the places of which 
 we have spoken; various phenomena, of which more here- 
 after, indicate it generally in all the spaces that subsist be- 
 tween the organs; it is only more strongly marked, wherever 
 these spaces are most sensibly defined. It will easily be per- 
 ceived that the rounded forms of the organs, must render these 
 spaces very numerous. 
 
 140. The second division of the cellular tissue, furnishes 
 to each organ in particular, an envelope which is peculiar to 
 it, and which besides penetrates into its thickness; this peculiar 
 disposition, has given rise to two sub-divisions. The cellu- 
 lar tissue which forms the envelopes of organs textus cellu- 
 laris strictus has been considered by Bordeu as a kind of 
 atmosphere, which limits their morbid action and phenomena, 
 and prevents these latter from being extended from one to 
 another. This idea, adopted by Bichat, appears to me to have 
 but a slight foundation; the difference of their organization is 
 the sole cause of the insulation which the organs present in 
 their actions, as well as in their diseases. Be this as it may, 
 the cellular layer which surrounds the organs varies in thick- 
 ness they all show this in a degree more or less marked, those 
 only excepted, whose envelopes are of a different nature, that 
 is, of the ligamentous or serous tissues. The envelope which 
 this layer constitutes, is continuous with the common cellular 
 tissue on the one hand, and with that which occupies the inte- 
 rior of the organ, on the other. Its cellular envelope is variously 
 
OF THE CELLULAR TISSUE. 117 
 
 disposed, according to the form of the latter. The skin, the 
 mucous and serous membranes, the blood vessels, lympha- 
 tics and excretory canals which have only one surface free, 
 are connected with the cellular tissue on one side only, the 
 solid organs on the contrary, such as the muscles, are entirely 
 surrounded by it. Under the skin the cellular tissue forms a 
 layer generally extended, if we except the places where the 
 muscles and aponeuroses are inserted. This sub-cutaneous 
 tissue is more or less dense, according to the region it occu- 
 pies; it is the most so throughout the whole extent of the 
 median line, at the neck excepted, where this line is but 
 slightly defined. Bordeu has exaggerated this disposition in say- 
 ing that it divides the body into two halves: it is very evident, 
 that at a certain depth no traces of it are to be seen. In those 
 places where there is great motion, the cellular tissue is 
 more lax, as in the eye-lids, prepuce, scrotum, lips and vulva. 
 On the contrary, where the skin does not slide, as in the 
 palm of the hand, the sole of the foot, front of the sternum, 
 back, &c. it is tighter. The mucous membranes have their 
 adhering surfaces covered by a very dense cellular tissue, 
 usually styled the nervous membrane. That which covers 
 the adhering surfaces of the serous membranes is generally 
 flaky. That which is found round the canals, forms particu- 
 lar sheaths for them, particularly important to the arteries, but 
 it is also found about the veins, lymphatic trunks and excre- 
 tory ducts. This tissue forms a layer round the muscles, called 
 their common membrane. 
 
 141. That portion of the cellular tissue which penetrates 
 into the organs, which accompanies and envelopes all their 
 parts textus cellularis stipatusi& differently disposed in 
 the different organs. In the muscles it forms an envelope for 
 each fasciculus, and smaller ones for the secondary fasciculi and 
 for the fibres of which these latter are composed: thus the cel- 
 lular tissue of a muscle exhibits a series of canals, sheathed suc- 
 cessively within each other, and connected in the same way that 
 the envelopes belonging to the different organs continue with 
 the general envelope of the body. The lobes of the glands, their 
 lobules, and the grains which compose these latter, are sur- 
 
118 GENERAL ANATOMY. 
 
 rounded in the same way by successively smaller, cellular 
 envelopes, and which, apart from the rest of the gland, would 
 form a sort of cellular sponge. The organs composed of seve- 
 ral membranous layers, as the stomach, the intestine and 
 bladder have cellular tissue between their different layers. 
 Certain very compound organs, as the lungs, have more or 
 less cellular tissue round each of the parts which enter into 
 their structure: the quantity of cellular tissue is generally 
 proportioned to the number of different parts that the organ 
 contains. For in proportion as the cellular tissue is divided 
 and subdivided to embrace the finer parts of the organs, it 
 becomes itself finer, and its envelope thinner; thus it is that 
 the small arteries are surrounded by a finer tissue than the 
 larger ones. The envelopes formed by the cellular tissue are 
 in general thicker, in proportion as the parts execute more mo- 
 tions, hence the predominance of this tissue in the muscles over 
 the glands. Certain organs, such as ligaments, tendons, bones 
 and cartilages have no free and distinct cellular tissue in their 
 thickness. In order that it be apparent, it is necessary gene- 
 rally that the organs present appreciable intervals between 
 their component parts: thus the ligaments which have appa- 
 rent fibres, show the cellular tissue that separate these fibres 
 in the others none is to be found. 
 
 142. Not only does the cellular tissue enter into the com- 
 position of all the organs, it also forms the basis of them all 
 textus organicus, seu parenchymalis and composes per se, 
 several of them: this it is, or the fibre or substance that forms 
 it, if you will, that constitutes (varying only in degrees of 
 consistence) the serous membranes, the dermis, the vessels, 
 the ligamentous tissue, in a word, almost all the parts, with 
 the exception of the nerves and muscles, even these, differ 
 from it only in the addition of the globules. The horny and 
 epidermic parts, alone have nothing in common with the cel- 
 lular tissue. Haller and some other anatomists have placed 
 the spongy or cavernous tissues and aerial vesicles of the 
 lungs in the cellular tissue; but these parts have a peculiar 
 disposition, which will not allow them to be confounded with 
 the cellular tissue. The cavities of the hyaloid membrane, 
 
OF THE CELLULAR TISSUE. 1 t 5 
 
 also, included by Haller in the tissue of which we are speak- 
 ing, should be distinguished from it. 
 
 143. Anatomists have not yet agreed on the internal con- 
 formation of the cellular tissue. Some of them, with Haller, 
 considering it as having distinct cells, of a determined form 
 and size, made by the multiplied intercrossings of laminae and 
 filaments. Others again, as Bordeu, Wolff, and Meckel, say 
 that this tissue is merely a viscous, tenacious, coutinuous sub- 
 stance, unfurnished with laminae and cells, and that these lat- 
 ter, when they do exist; are the result of the operations made 
 to demonstrate them. The following is what we learn upon 
 this subject by inspection. 
 
 When we examine the section of a muscle by the glass, we 
 perceive that the fibres are not in contact, but are separated 
 by a transparent substance; if we draw aside these fibres, this 
 substance forms filaments, which are extended as we draw, 
 and finally break. Those who look upon the cellular tissue as 
 a sort of gluten, take this opportunity to remark, that it would 
 be precisely thus, if these fibres were separated by glue. 
 Around the entire muscle, we find an evident lamina, which, 
 in the same way, by distension, takes the form of filaments; 
 by blowing air under this lamina, it is transformed into irregu- 
 lar cells, separated by species of partitions. It would appear 
 then, that round the smaller parts, the cellular tissue, is really 
 a sort of jelly, while around the larger, its laminae are appa- 
 rent If, instead of air, we inject water, and freeze it there, 
 irregular crystals filling the cells are obtained: a similar result 
 follows the injection of a coagulable matter. But these cells 
 are never regularly disposed, nor are their forms geometrical, 
 as has been said ; their figure may even vary, when produced 
 at repeated trials in the same spot. 
 
 Whether the laminae, fibres, and cells, are pre-existent in 
 the cellular tissue, or whether they depend only on its separa- 
 tion, is a question, on which, as we have seen, there is much 
 doubt. Possessed of a sufficiently distinct organization, where- 
 ever its thickness is considerable, this tissue seems inorganic 
 in those places where it is thinner, and even different between 
 the smaller fibres of the muscles. In admitting the existence 
 
120 GENERAL ANATOMY. 
 
 of the cells, should we regard them as closed on all sides, and 
 communicating only after the rupture of their walls, or as 
 pierced or porous cells, opening into those adjoining, or finally, 
 as areola, spaces open on all sides, like those irregular ones, 
 which subsist between the fibres and laminae of the cellular 
 tissue? The latter appears the most probable. But these areolae 
 in their ordinary state, are of an extreme smallness, micro- 
 scopic with contiguous parietes, and the enlargement they ex- 
 perience by infiltration, inflation, etc, tearing and altering them 
 greatly, can give no exact idea respecting them. 
 
 144. The cellular tissue, in other respects, is precisely as 
 though it were spongy, liquids and gases penetrating it with 
 the greatest facility. In fact, 1st, the serum, in the dropsy 
 of this tissue, always flows into its most depending parts, or 
 into those which offer the least resistance; the situation of the 
 patient has much influence, as to the place it occupies; exter- 
 nal pressure displaces it equally; one single incision often suf- 
 fices for its issue; 2d, the water thrown in by artificial injec- 
 tions, flows through the cellular tissue in the same manner 
 from cell to cell; 3d, air infiltrated in emphysema, and that 
 which is artificially introduced, present the same phenomena; 
 4th, in echymosis, the blood is infiltrated in a similar way, 
 spreads extensively through the cellular tissue, and is dissemi- 
 nated more and more. All this demonstrates a general com- 
 munication between the areolae: those who do not admit these 
 to exist, explain these facts by the slight consistence of the 
 cellular tissue. Whether the areolar fibres or lamina, of the 
 cellular tissue, be inherent in this tissue, or are only the effects 
 of the various agents of distension, it is always certain, that in 
 this respect, it presents remarkable differences. In certain 
 places it is always fibrous or filamentous; in others, it is chiefly 
 laminated, or lameliated, as in the eye-lids, scrotum, prepuce, 
 the labia of the vulva, and between the very moveable mus- 
 cles; the more soft and lameliated, the larger are the areolae it 
 forms; and these large areolae. seem to be the first rudiments 
 of the serous cavities. 
 
 145. When in thin lamina the cellular tissue is colourless; 
 it appears whitish when its thickness is increased, and particu- 
 
OF THE CELLULAR TISSUE. 121 
 
 larly when distended; it is semi-diaphanous. Its powers of 
 cohesion varies ; in some places, as between the muscular fi- 
 brilli, it is simply that of a slightly viscid liquid ; in others 
 again, its resistance is almost equal to that of the fibrous tissue. 
 This tissue is very extensible, and very retractile, as may be 
 seen by inflating it, and making an incision, it then contracts 
 forcibly, driving out the distending air. Its chemical proper- 
 ties have been carefully studied by Bichat. Deprived of wa- 
 ter by dessication, it loses a part of its physical qualities, and 
 acquires new ones; in this state, it is hygrometrical, and re- 
 sumes its original aspect when placed in water, a peculiarity 
 it possesses in common with almost all the organic tissues. 
 Exposed to heat it dries rapidly, becomes crisp, and ends in 
 burning like all the other tissues, leaving, however, but little 
 ashes. It strongly resists decoction, and is dissolved only by 
 long continued ebullition. It putrefies very slowly: to accom- 
 plish the entire decomposition of this tissue, by maceration, re- 
 quires several months, even without renewing the water; it is 
 converted at last into a viscid substance resembling mucilage, 
 and furnishes divers products which rise to the surface of the 
 liquid. Fourcroy considered it composed of gelatin; John 
 detected in it besides, a small quantity of fibrin, and the phos- 
 phate and carbonate of lime. 
 
 146. The intimate nature of the cellular texture, has given 
 rise to a great number of hypotheses. Ruysch supposes it to 
 be entirely vascular; Mascagni, who scarcely mentions it, says 
 it is composed of white vessels; Fontana of tortuous cylinders; 
 others regard it as an expansion of the nerves. The only base 
 we should admit in it, is the cellular fibre or substance, 68, 85. 
 It is traversed by a great number of vessels, and serous vessels 
 particularly; but it should not be considered as wholly consist- 
 ing of them, for it is it that definitely forms the parietes of the 
 extreme vessels. The cellular tissue has canals or cavities pe- 
 culiar to it. They are the little spaces or areolae with which it 
 is hollowed, or that the liquids excavate as fast as they are de- 
 posited in it, and which by their communication make it a 
 spongy and permeable body. Almost all those who have paid 
 particular attention to injections, Haller, Albinus, Prochaska, 
 
GENERAL ANATOMY. 
 
 &c. have placed it among the solid or non-injectable parts, q 
 v. d. that it is without the circulating track of the vessels. The 
 blood, nevertheless, may pass into its canals or peculiar cavi- 
 ties, but then there is inflammation. The nerves, in like man- 
 ner, do not appear to stop or terminate in the cellular tissue. 
 This tissue forms a true and separate substance, traversed by 
 nerves and blood-vessels in every direction, and in which a 
 liquid is left by the latter only. 
 
 147. It is, in fact, continually bathed and humected by a 
 very tenuous liquid, which it imbibes, and whose quantity is 
 so small as to be scarcely sensible; the word vapour is conse- 
 quently used to designate this fluid. If we make an incision, 
 in the cellular tissue of a living animal, it is this liquid that 
 moistens the fingers; introduced into the wound in cold 
 weather, a vapour arises from the divided tissues, that is con- 
 densed and rendered visible, by the external air; it arises both 
 from the cellular tissue and the white vessels. In anasarca, the 
 liquid of the cellular tissue, accumulated, and perhaps altered, 
 greatly resembles the serum of dropsical patients; it is coagula- 
 ble like the latter, and appears even to contain a certain quan- 
 tity of albumen, water, and some salts. 
 
 148. The cellular tissue is the first part formed in the em- 
 bryo; it is also found in the very lowest order of animals. This 
 tissue, at first liquid, and very abundant, diminishes in propor- 
 tion as the organs become developed, and acquires consistence 
 at the same time. Even at birth, it is still diffluent in the in- 
 terstices of the muscles, and very soft under the skin. Its den- 
 sity continues to increase in old men, and it is almost fibrous 
 at a very advanced age in those parts which in the infant are 
 very soft. The cellular tissue is looser and more abundant in 
 women than in men. JBlurnenbach, gives as a character of the 
 organization of man, compared to that of other animals, the 
 presenting of a softer and tenderer tissue, which gives him a 
 greater facility of motion. 
 
 149. The power of formation of the cellular tissue is high> 
 Jy developed: it is the first part formed; it increases acciden- 
 tally, is completely formed at once and is reproduced when 
 it has been destroyed, with the greatest promptitude, as is 
 
OP THE CELLULAR TISSUE. 123 
 
 seen in wounds, adhesions, &c. It possesses a power of con- 
 traction depending in part, upon its elasticity and partly upon 
 its irritability. This latter quality is here called, fibrillary, 
 staminal, tonic contractility: it is manifested by the motions 
 of the liquid this tissue generally or accidentally contains, 
 and by the general or local tightening it experiences in vari- 
 ous cases; it is not very evident that the nervous force influ- 
 ences or determines its contractions. It has no sensibility 
 except in a state of inflammation. 
 
 150. The uses and functions of the cellular tissue are very 
 important; it is it that determines the form of all the parts. It 
 is the only lien that unites them with each other: upon its 
 cohesion depends that of all the other tissue. By its elasticity, 
 it facilitates the movements and replaces the organs in the state 
 they were in previous to being displaced, when these move- 
 ments have ceased : thus <so do these latter perform their 
 functions the more easily in proportion as the cellular tissue 
 is perfect. 
 
 It is the seat of a perspiratory secretion which on account 
 of its extent is very abundant. Does the liquid there given 
 out by the extreme vessels experience a sort of circulation or 
 movement of translation? Of this we are totally ignorant. 
 It is only in cases of morbid accumulation, that we see the 
 infiltrated liquid change its place in obedience to weight and 
 pressure, &c. It has been supposed, but without any solid 
 reason, that this liquid is in a state of continual agitation, of 
 which the diaphragm, by its alternate motions upwards and 
 downwards, is the principal cause; that there are currents in 
 various directions and that, for example, it is the secret way 
 by which liquids pass from the stomach to the bladder, a sup- 
 position disproved by all exact observations; that it is the chan- 
 nel of metastasis, &c. However it may be, the liquid is after- 
 wards taken back again by the vessels, so that this tissue is 
 intermediate between perspiration and resorption. The tonic 
 contraction of the cellular tissue is the agent that propels the 
 serum of this tissue into the vessels. 
 
 The cellular tissue is in fact the essential organ of absorp- 
 tion ; it forms the mucous body of the skin, the spongy sub- 
 
124 GENERAL ANATOMY. 
 
 stance of the villosities of the mucous membranes, parts which 
 absorb, and whence, absorbed substances pass into the vessels. 
 Previous to being brought into the vessels, the matters ob- 
 sorbed by the cellular tissue, which by way of opposition to 
 the rest we may call external or superficial, no doubt undergo 
 elaboration or changes. As foreign matters, before entering 
 the vessels, have to pass through the cellular tissue, the organ 
 of absorption, so also those which are thrown out from the 
 vessels, traverse the cellular tissue, the organ of secretion, 
 previous to being deposited on the surfaces on which they 
 are poured. 
 
 The cellular tissue which envelops each organ in particular, 
 has been considered as forming for it an isolating atmosphere, 
 which circumscribes its actions, whether hygid or morbid: 
 observation frequently contradicts this assertion, and when 
 the fact is so, it is in the peculiar texture of the organ and the 
 variety of agents, that we must seek an explanation, and not 
 in this pretended atmosphere. 
 
 The cellular tissue which penetrates into the thickness of 
 the organs, reunites all their parts. 
 
 As to the organic cellular tissue or parenchyma, it forms 
 the base or essential element of each organ, and presents these 
 remarkable differences. In the most rational hypothesis re- 
 specting the seat of nutrition^ it is admitted that the nutritive 
 matter is deposited out of the vessels in the cellular substance, 
 which is the base of the organs, to be assimilated to them, and 
 that it is thus, the essential organ of nutrition. However it 
 may be as to the hypothetical uses, attributed to the cellular 
 tissue, it has incontestably very important ones in the organ- 
 ism. 
 
 151. The phenomena of the cellular tissue either in health 
 or sickness, are connected with those of the other parts. Thus 
 organic lesions of the heart, and the derangements of the pul- 
 monary respiration and perspiration, often occasion there an 
 accumulation of serum. The same thing takes place in the 
 alterations of various secretions, that of cutaneous transpira- 
 tion particularly. Its inflammations, generally cause fever. 
 The suppurative inflammation which is occasioned in it by 
 
OF THE CELLULAR TISSUE. 125 
 
 seton, &c. frequently reduces the inflammations of the other 
 organs. 
 
 152. The cellular tissue is subject to various morbid 
 changes. When broken into and exposed, it inflames, becomes 
 covered with fleshy buds, suppurates, and at last covers it 
 \vith a cicatrix or new skin which will be described hereafter. 
 (Chap, iii.) 
 
 When it is cut and its divided surfaces are again brought 
 into contact, they, at first, agglutinate by means of a liquid 
 poured out from the divided surfaces when the bleeding and 
 pain have ceased. A little later, and this organizable substance 
 becomes a highly vascular tissue: then it is no longer possi- 
 ble to separate the lips of the wound without renewing the 
 pain, and reproducing the flow of blood. This new tissue re- 
 mains for a long time, more compact, firm and vascular than 
 the cellular tissue it unites and with which it is at last con- 
 founded. 
 
 It is by a similar process that every union of divided parts 
 .takes place, with modifications relative to each tissue, which 
 will be examined in their proper place. 
 
 It is, also, in this way that adhesions are formed between 
 contiguous surfaces of the serous arid tegumentary membranes, 
 adhesions that will be described when we come to treat of 
 membranes. (Chap, ii, iii.) 
 
 The cellular tissue is susceptible of an extroardinary growth : 
 when exposed, it sometimes shoots out in a kind of vegetation 
 or vascular exuberances. The reproduction of this tissue is in 
 general so much the easier, as the quantity that remains in 
 the spot from which it was taken is great: it seems that this 
 reproduction depends, in a great measure, upon the extension 
 of the pre-existing cellular tissue. 
 
 The inflammation of the cellular tissue, or phlegmon, is 
 characterized by various changes in this tissue. The first of 
 these changes, is a highly marked increase of vascularity. 
 The inflamed cellular tissue becomes, besides, sensible and 
 painful; it entirely loses its permeability; liquids can no longer 
 pass through it; its consistence augments and its tenacity di- 
 .m.inishes; pressure tears and breaks, instead of elongating it, 
 
126 GENERAL ANATOMY. 
 
 as before. This sort of fragility which the cellular tissue ac- 
 quires, explains certain phenomena; it explains why the liga- 
 ture of a vessel frequently produces a section of the surround- 
 ing tissue, why at the termination of peritonitis, it is so easy 
 to separate the intestine from the coat formed by the perito- 
 neum. Inflammation of the cellular tissue may terminate 
 insensibly, and then this tissue gradually reassumes all its pro- 
 perties: this is seen in that kind of termination called, by re- 
 solution. In other cases the cellular tissue secretes a peculiar 
 liquid called pus, and which will be described hereafter this 
 constitutes the termination by suppuration. This liquid is 
 generally collected in one point which extends itself progres- 
 sively to the circumference, as long as the secretion continues. 
 This is one of the perspiratory kind of secretions; pus is pro- 
 duced directly from the blood and even presents in its com- 
 position some analogy with this fluid. It only requires the 
 disease to progress slowly, for the walls of the abscess to be- 
 come lined with a membrane. This membrane is doubled 
 externally by a layer, more or less thick, of compact cellular 
 tissue. This layer is not so well marked when the disease has 
 lasted a certain time, and the membrane is then almost com- 
 pletely isolated, the cellular tissue having reacquired its pro- 
 perties around it. Abscesses are the seats of a continual 
 secretion and absorption; the entire absorption of the pus 
 they contain, and the effects which the presence of this fluid 
 sometimes produces in the economy are proofs of it. The pus 
 formed in the interior of abscesses most commonly arrives at 
 last at the surface. The abscess is emptied, its walls are con- 
 tracted, remain indurated for some time, and end by reassuming 
 all the characters of cellular tissue. When the secretion and 
 flow of pus continue, the canal by which the abscess commu- 
 nicates without, and which is called sinus or fistula, becomes 
 invested with a distinct membrane, that presents the charac- 
 ters of the mucous membranes, and whose history belongs to 
 that of the latter. After certain gangrenous inflammations 
 the cellular tissue becomes so tightened by the loss of sub- 
 stance it has undergone, that the skin, the muscles, and the 
 aponeuroses become confounded: but in this case, if the pa- 
 
OF THE CELLULAR TISSUE. 12V 
 
 tient is young and robust, the cellular tissue can be repro- 
 duced with all its properties. The inflammation of the cellu- 
 lar tissue sometimes continues for an indefinite period, so 
 that it remains hard and impermeable : this constitutes in- 
 duration. This state is found in the callosities of ulcers and 
 fistulas, which are evident results of a chronic inflammation of 
 the cellular tissue. The Barbadoes disease,a species of elephan- 
 tiasis, presents similar characters of induration. 
 
 New-born children are subject to an induration of the cel- 
 lular tissue, in which the inflammatory character is not found: 
 this induration is observed under the skin, and sometimes in 
 the spaces between the muscles. It is according to the ob- 
 servations of M. Breschet, merely a secondary phenomenon 
 of the imperfect closure of the foramen ovale, or of a defec- 
 tive or imperfect respiration. 
 
 Air may pass into the cellular tissue; this constitutes em- 
 physema. When the patient does not die from this accident, 
 the rarified air escapes through the incisions made for that pur- 
 pose, or through the wounds that may have previously existed, 
 or it may combine with the fluids found in the cellular tissue, 
 and disappear by absorption. Leucophlegmatis or anasarca, 
 consists of an accumulation of serum in the cellular tissue. In 
 ecchymosis,thecellular tissue contains blood dispersed through 
 its areolas. All the organic fluids may pass accidentally into 
 this tissue, in which, when they are of an excrementitial na- 
 ture, they occasion inflammations more or less violent. 
 
 Solid foreign bodies, introduced into the cellular tissue, do 
 not, commonly, remain long in the same place, but like pus, 
 are generally carried to the surface, and if they are heavy, par- 
 tially obeying the laws of gravition. It is very evident, that it 
 is not by traversing pretended cells, that these bodies travel 
 thus across and through the cellular tissue. The latter pre- 
 sents around them, three distinct phenomena: it secretes pus 
 around their surfaces, it re-unites and re-assumes its softness 
 and permeability behind, and ulcerates before them. Here, then, 
 we find three of the kinds of inflammation admitted by John 
 Hunter, viz: Jthe adhesive, suppurative, and ulcerative : the 
 ensemble of these phenomena has received the name of eli- 
 18 
 
128 GENERAL ANATOMY. 
 
 minative inflammation. It sometimes happens that foreign 
 bodies remain in the cellular tissue, either on account of the 
 lightness of their specific gravity, or of the density of the sur- 
 rounding tissue: a membrane, in this case, is formed around 
 them. 
 
 The cellular tissue contains, in some cases, foreign animated 
 bodies or worms : the cysticercus cellulosa, so called on ac- 
 count of its seat in the cellular tissue, ihejllaria medinensis, 
 or little dragon, whose existence can not be questioned, have 
 been found in it, and in animals the larvae of the oestrus. 
 
 The cellular tissue may experience various changes. The 
 serous, fibrous, bony, and cartilaginous transformation, which 
 are developed in the cellular tissue, will be described with the 
 natural tissues to which they belong. 
 
 The cysts, whose seat is in the cellular tissue, will be like- 
 wise spoken of, when treating of the serous and tegumentary 
 membranes, to which they are very analogous. 
 
 When an organ happens, accidentally, to disappear, we say 
 it is transformed into cellular tissue; this is, perhaps, not ex- 
 actly correct; the cellular tissue in this case merely taking the 
 place of the wasted organ, which previously kept it at a distance. 
 
 Various degenerations may be regarded as especially apper- 
 taining to the cellular tissue: it is this tissue which appears to 
 be their base, for they are every where similar. As they are 
 common, however, to all the organs, I shall speak of them 
 when I have done with the history of all the other tissues. 
 Wherever, in the interstices of the organs, the cellular tissue 
 is free, it is affected by these degenerations, as well as in the 
 places where it constitutes a part of the organs themselves. 
 
 SECTION II. 
 
 OF THE ADIPOSE TISSUE. 
 
 153. The adipose tissue, so called on account of the fat 
 (adeps) it contains, results from Ihe re-union of very small, 
 microscopic vesicles, clustered and grouped in greater or less 
 
OF THE COMMON ADIPOSE TISSUE. 129 
 
 number, united by laminous cellular tissue, and fulfilling the 
 office of a reservoir for the fat. It is divided into two kinds: 
 one is the common adipose tissue, or fatty tissue, properly so 
 called; the other is the adipose or medullary tissue of the bones. 
 
 ARTICLE FIRST. 
 OF THE COMMON ADIPOSE TISSUE. 
 
 154. This has been called the fatty cellular tissue, fatty 
 membrane, web, tunick, adipose, vesicles, &c.: it has also been 
 styled the fatty pannicle, because it forms a layer immediately 
 under the skin. 
 
 155. This tissue, for a long time, was confounded, with 
 the cellular tissue, which was sometimes said to contain se- 
 rum, and at others fat, and in the latter case, to constitute the 
 fatty tissue. Malpighi, was one of the first who raised a doubt 
 on this subject, and who saw the fat form a kind of grains at- 
 tached to the blood-vessels. Swammerdam has also seen that 
 the fat is a liquid oil inclosed in little membranes. Morgagni 
 acknowledges, also, that the fat contains grains which he corn-- 
 pares to those of glands. Bergen was one of the earliest 
 writers who distinguished two kinds of cellular tissue, one of 
 which, called by him luminous, corresponds to the fatty tissue. 
 W. Hunter has given the distinctive characters of this tissue, 
 characters afterwards acknowledged, and more or less exactly 
 determined by Jarisen, Wolff, M. Chaussier, Prochaska, Gor- 
 don, Mascagni, myself &c. Haller denies the existence of 
 this tissue, admitting only the areolae of the cellular tissue as 
 parts containing fat; his opinion has been adopted by Bichat, 
 M. Meckel, &c.; we shall see, however, further on, that this 
 opinion is but slightly founded. The fatty tissue has been 
 carefully described in several works,* and figured in some of 
 them.t 
 
 * M. Malpighi, De omento, pinguedine, etc. in ejusd. op. onin et posthum. 
 Bergen, op. cit. W. Hunter, op. tit. Wolff, op. dt. W. X. Jansen. Pin- 
 guedinis animalis consideratio physiologica et pathologica. Lug-d. bat. 1784. 
 
 f Mascagni. Prodrome della grande anatomia. 
 
130 GENERAL ANATOMY. 
 
 156. The adipose tissue presents appearances varying ac- 
 cording to the places where it is examined. Under the skin 
 it forms a layer more or less thick and everywhere extended. 
 In the orbits, in the thickness of the cheeks, in the interior of 
 the pelvis, front of the pubis, about the kidneys, &c., it re- 
 sembles rounded masses. On the loose edge of the epiploon, 
 in the epiploical appendages of the intestine, and on the level 
 of the openings which are found on the exterior of the perito- 
 neum, these masses are pyriform and pediculated. In the 
 epiploon, the fat is disposed in fillets or ribands that follow 
 the track of the vessels. 
 
 157. Although the fat, is not so universally distributed 
 as the cellular tissue, it is nevertheless, found in many places. 
 
 The vertebral canal contains a small portion of it outside 
 the dura-mater. It exists in considerable quantities about the 
 head, particularly in the face, in the parotid notches, in the 
 cheeks, &c. In the neck this tissue is more abundant behind 
 than before. In the external and internal parts of the thorax it 
 exists in remarkable quantities in the vicinity of the heart, as 
 well as between the pectoral muscles and about the mammae. 
 The fat of the abdomen is principally situated outside the kid- 
 neys, in the pelvis, in the thickness of the mesentery, of the 
 epiploon and of the appendica epiploicoe. In the limbs, fat is 
 more abundant about the articulations in the direction of the 
 flexion, as well as in those places that are exposed to constant 
 pressure, as the nates and the sole of the foot. 
 
 The fatty tissue varies according to the organ in which it is 
 placed. That which is under the skin always remains, cases 
 of extreme emaciation excepted, and is continued into the 
 areolae of the skin. There is none found under the mucous 
 membranes. The synovial and serous membranes, on the con- 
 trary, are lined by this tissue, particulary in the thickness of 
 their folds. The adipose tissue which surrounds the muscles, 
 penetrates likewise into the thickness of those that are divided 
 into distinct fasciculi, as the great glutoeus, &c. In the lobu- 
 late glands it is seen in the spaces between the lobes. The 
 sheaths of vessels, generally contains but little. The large 
 
OP THE COMMON ADIPOSE TISSUE. 131 
 
 nerves as the ischiatic nerve have small masses of it between 
 their fasciculi. The fat in the bones is considered separately. 
 
 158. In particular parts no fat is to be found, as under the 
 skin of the cranium, of the nose, of the ear, of the chin, where 
 the median line is entirely deprived of it; there is also but 
 very little between the skin and cuticle. Scarcely any is found 
 opposite the insertion of the deltoid, occasioning that depres- 
 sion which exists in even the fattest subjects. This fluid is 
 not to be found, about the long and thin tendons, nor in the 
 spaces of those muscles which produce the great movements, 
 as between the triceps and anterior rectus femoris, the biceps 
 and the brachialis externus, the gastrocnemii and the soleus. 
 The substance of the viscera has seldom any fat, nor is there 
 any in the parietes of the stomach, or of the uterus, in the liver 
 or the spleen. The eye-lids, the penis, the small labia pu- 
 dendi, are also deprived of it. The quantity of fat existing 
 in the human body, greatly varies ; but in some parts of it 
 none can be found, not even in the most excessive state of 
 obesity, while on the contrary there are others, in which the 
 most complete marasmus never cause it to disappear entire- 
 ly. In the adult man of ordinary plumpness, the fat forms 
 about the twentieth part of the weight of the body. 
 
 159. The fatty tissue is generally of a yellowish white 
 colour and of a soft consistence, but varying according to the 
 region to which it belongs, the age, &c. 
 
 160. Whatever be the external form of the adipose tissue, 
 the masses it presents are divided into smaller ones, from the 
 size of a pea to that of a filbert, smaller about the head, larger 
 round the kidneys. These masses are buried in the cellular 
 tissue; their form varies; generally rounded, it is elongated, 
 ovoid on the median line of the abdomen, one of the eMremi- 
 ties holding by the skin, the other by the aponeuroses. By 
 dissection we can reduce them into adipose lobules or grains, 
 which examined microscopically, appear themselves to be 
 composed of an infinitude of little vesicles, from the sixth to 
 the eight hundredth part of an inch in diameter. We may then 
 consider the fatty tissue as composed of conglomerate vesi- 
 cles, united in grains, which in their turn, are collected to 
 
132 GENERAL ANATOMY. 
 
 form masses. The result of this disposition is that the struc- 
 ture of this tissue is not areolar, but rather resembles that of 
 the fruits of the family of the hesperides, such as oranges and 
 lemons which present in the same way, and very plainly, 
 ^membranous vesicles attached to partitions that divide them. 
 'The fatty vesicles, as well as the grains and the masses which 
 they form, are furnished with small foot-stalks, formed by the 
 vessels situated in the intervals, and may be compared, in this 
 respect, to grapes supported by their pedicles. These vesi- 
 cles, however, are so excessively thin that it is impossible to 
 distinguish their parietes; but there are many certain proofs 
 of their existence. In fact, if the fat were loose or free, it 
 would not form regular and distinct masses. It is an error in 
 Haller and others to pretend that this form is proper to fat or 
 inherent, for it presents no globules, and by itself has no de- 
 termined figure. If we place under the microscope, some of 
 these vesicles plunged into warm water, no oil can be seen on 
 their surface; but on breaking them, a few drops of it escape 
 and float on the surface of the liquid. Add to these considera- 
 tions, that the fat in the living body being fluid, as is proved 
 by its flowing on the division of the tissues, it ought to pass 
 through like serum, if not in health, at least in disease; but 
 this never takes place, and all that has been said about the in- 
 filtration of fat to explain the formation of the pendent mam- 
 mae of certain nations, the salient buttocks of others, the dorsal 
 humps of some animals and the immense tails of others, &c., 
 presents only a collection of contradictory facts and absurd 
 reasonings. Roose and Blumenbach have argued against the 
 existence of these vesicles, from the development of fat in 
 parts were these little apparatuses do not exist ; thence they 
 conclude, that these latter are not necessary to the production 
 of this fluid: fat is, in fact, produced in the cellular tissue, but 
 it then forms vesicles, instead of being simply contained in 
 the open areolse. 
 
 161. The cellular tissue between the adipose vesicles is very 
 delicate, as it commonly is between the more tenuous parts of 
 our organs: these vesicles seem scarcely to adhere to each other, 
 as they may be separated without their opposing any resistance. 
 
OF THE COMMON ADIPOSE TISSUE. 133 
 
 The cellular tissue becomes more distinct between the adipose 
 grains and very apparent between the masses, the latter, in 
 some places, even being separated by strong fibrous laminae, 
 as may be seen in the sole of the foot, and whose use is to give a 
 high degree of elasticity to the fat. In other places, the adipose 
 masses are united and supported by firm cellular laminae, 
 as in the cranium, back, &c. in others by a lax tissue as in 
 the groin, &c. In order, however, to have a distinct view of 
 the cellular tissue that is situated between the fatty lobes, we 
 must examine it in subjects affected with anasarca or emphy- 
 sema: by this examination we shall also be convinced, that 
 the fat is not free in the areolse of the cellular tissue; for how- 
 ever extensive, however deep be these infiltrations, they may 
 separate, even dissect, as it were, the adipose grains, but the 
 fat is never mixed with the infiltrated fluid. 
 
 The blood vessels of the fatty tissue are injected with ease. 
 They are also very visible when we examine those parts, 
 where the blood that remains fluid has been naturally carried 
 after death. These vessels are most apparent in old persons, 
 the fatty lobules being more distinct. Their divisions and 
 sub-divisions end in microscopic vesicles. Malpighi once 
 thought that these vessels were surmounted with a secretory 
 apparatus, and a duct which emptied into the reservoir of the 
 fat; he afterwards discovered and acknowledged that this dis- 
 position did not exist. The absorbent vessels of the vesicles 
 are less known than the veins and arteries. Mascagni, it is 
 true, says they are composed of an internal layer of lympha- 
 tic vessels, and of an external one of blood vessels; but he 
 produces no fact in support of this opinion. It is not known 
 whether or not these vesicles have nerves. 
 
 When there is no fat, there are no vesicles. When this 
 fluid ceases to exist in a part, they disappear. Hunter says, 
 however, that they may be distinguished even when empty; 
 but I do not think this is so. Where they disappear, they 
 become confounded with the cellular element. 
 
 162. Human fat, extracted from the fatty tissue which 
 contains it, and purified, by washing, fusion and filtration, 
 has the general properties of fixed oils. It is inodorous, and 
 
134 GENERAL ANATOMY. 
 
 of a sweet and disagreeable taste; its yellowish colour is owing 
 to a colouring principle that is soluble in water and carried off 
 in washing. It is not so heavy as water, its fusibility varies 
 according to its composition : it is, in general, fluid at the tem- 
 perature of the body and under it, sometimes even greatly so, 
 as at 15R. for instance; it is insoluble in water, and-but little so 
 in cold alcohol: it is not acid ; that which Crell admitted it to 
 contain, is the result of distillation, an operation, in which fat 
 gives out carbonic, acetic, and sebaic acids, with several other 
 products of the reaction of its elements. It is converted into 
 a sweet principle, and the margaritic and oleic acids, by the 
 action of strong alkaline bases. Exposed to the air and light 
 it becomes rancid, producing a volatile acid of a strong smell. 
 The elementary composition of several of the fats, has been 
 determined by M. M. Berrarde, and Th. de Saussure; it is a 
 combination of carbone, hydrogen and oxygen, varying in 
 proportion, according to the kind of animal: that of human fat 
 has not been determined. 
 
 Previous to the labours of M. Chevreul,* fat was considered 
 as a simple principle. He has demonstrated that it is essen- 
 tially formed of two organic materials j stearine, fusible at 
 about 50 R. and elaine, fluid at zero; it is from the proportion 
 of these, that results the degrees of fusibility of each kind of 
 fat. These two direct materials are separated by treating the 
 fat with boiling alcohol; by cooling, the greater part of the 
 stearine is precipitated along with a little elaine, the latter re- 
 mains in solution, in the alcohol, with a small part of stearine. 
 We can also separate them by congelation, which first fixes 
 the stearine with a little elaine. They may also be isolated by 
 the absorption of unsized paper, which takes up the elaine and 
 leaves the stearine on the surface. 
 
 163. The fat of the adipose tissue, is not the only fatty 
 matter found in animal organization, and in that of man in 
 particular. A crystallizable fatty substance is found in the 
 blood. Malpighi, Haller, and others, thought that free fat cir- 
 culated with the blood; this is a mistake, at least, I have never 
 
 * Annuks de, Chimie. torn. xciv. Ann. de. Chim, et de Phys. torn. ii. et vii. 
 
OF THE COMMON ADIPOSE TISSUE. 135 
 
 seen it; butM. Chevreul has recently discovered in the blood, 
 a fatty matter, held in solution by the other materials of that 
 fluid. Butter is another fatty, coloured and odorous substance, 
 held in solution in the milk. There is also in the nervous 
 substance, a fatty, crystallizable matter, analogous to that of 
 the blood. Finally, in cases of disease and cadaveric changes, 
 other fatty matters are found in the human body. 
 
 164. The adipose tissue, in animals, presents some differ- 
 ences; it exists in the greater numbers; it is found in the ar- 
 ticulata, the mollusca, and the vertebrata. In the latter, the 
 fat presents various degrees of consistence, colour, &c.; it is 
 very fluid in fishes and the cetacea; the head of the physeter 
 macrocephalus, contains a liquid oil, in which is found a con- 
 crete fatty matter, called spermaceti or cetine. In the hog it 
 is soft, forming lard, firm in the ruminantia, where it is called 
 tallow, &c. The volume of the adipose vesicles is not the 
 same in all animals: according to Wolff, they increase succes- 
 sively, in the hen, the goose, man, the ox and the hog. Fat 
 accumulates also, in different regions, in different animals, as 
 on the back of the camel, the tails of some sheep, &c. The 
 Bushman tribe is remarkable for the fatty protuberance of 
 the rump in the women : an example of which has been recently 
 seen in the Hottentot Venus, exhibited in Europe. 
 
 165. The different degrees of plumpness establish great 
 differences in the quantity of fat. In a complete state of obesi- 
 ty, it forms from the half to four-fifths of the total weight of 
 the body. In extreme leanness, on the contrary it exists only 
 in some places. Women have, commonly, more of it than 
 men. It varies remarkably, according to age. The foetus has 
 none at all, until the period of gestation is half over. From 
 this epoch to the birth, fat successively accumulates in the dif- 
 ferent parts. It is found at first under the skin only, and is 
 there produced in isolated grains, which render its study at 
 this age peculiarly easy. At birth, a large quantity is already 
 found under the integuments, and in the thickness of the 
 cheeks ; the epiploon also, has some isolated grains of it. The 
 quantity of fat,augments with the increasing growth, and ends by 
 
 occupying the interstices of the muscles, but a long time elapses 
 19 
 
136 GENERAL ANATOMY. 
 
 before it is produced round the viscera. The state of maturity* 
 or the period in which the growth is terminated, is that of 
 obesity also: the latter is sometimes observable in children, 
 but very rarely. In old age, the quantity of fat is diminished, 
 chiefly under the skin : this fluid then exists, especially in the 
 interior, as about the heart, in the medullary cavities of the 
 bones, &c. 
 
 166. The properties and functions of the fatty tissue, relate 
 only to the secretion of the fat. This secretion is not made in 
 particular glands, nor in ducts: Heister and Fanton were the 
 first to doubt the existence of these glands, of which, since the 
 error of Malpighi on this subject, many authors have spoken.* 
 The secretion of fat is a perspiratory secretion, and Rigel was 
 wrong in endeavouring to revive the theory of fatty ducts, 
 which he did, at the same time he brought forward his hypo- 
 thesis upon the use of the renal capsules: according to this 
 author, the fat which surrounds the kidneys and its pelvis, is 
 formed in these capsules, whence it is carried by particular 
 ducts, which ducts, however, he had not been able to inject. 
 Does fat directly result from the organic action of the vessels 
 which deposit it in the adipose vesicles? or, is it already formed 
 in the circulating blood? or has it a yet more remote origin? 
 M. Ev. Hornet fixes its origin in the intestine; he thinks, that 
 like the chyle, it is a product of digestion, and that it is ab- 
 sorbed by the great intestine. This opinion is based, among 
 other facts, upon the existence of the fat, or the yolk of egg, 
 in the intestine of oviparous vertebrata, in the foetal or larval 
 state, and upon some morbid facts that are not very conclusive. 
 
 167. The fat is continually taken up by the absorbent ves- 
 sels; the action of these Vessels is demonstrated by its dimin- 
 ishing in quantity in several circumstances. This action is 
 equal to the secretion, when the quantity of fat remains the 
 same. The exhalation and absorption of the fat, is occasionally 
 very rapid, as proved by many facts. Children that have be- 
 come emaciated, in consequence of sickness, resume all their 
 
 * De usu glandulctrum superrenalium in anim. nee non de origine adipis 
 disq. anat. philos. Hasniae, 1790, 
 f Phibsophical Transactions, ann. 1813. 
 
OF THE COMMON ADIPOSE TISSUE. ' 137 
 
 plumpness in a few days. Animals that are famished, such as 
 hogs, very soon become fat. Certain birds fatten, it is said, in 
 moist weather, in less than twenty-four hours; emaciation, in 
 many cases is equally rapid. The circumstances most favoura- 
 ble to the secretion of fat, are castration, and the absolute rest 
 of the animal and intellectual organs. These causes are fre- 
 quently united when we wish to fatten animals : they produce 
 a similar effect upon man. Habitual bleedings, sweet and 
 amylaceous aliments, are also regarded as favouring the pro- 
 duction of fat. Besides these, there are unknown circum- 
 stances, which appear to act in the same way, for we remark 
 extraordinary cases of obesity, for which it is difficult to ac- 
 count. The causes which accelerate the absorption of the fat, 
 are in general, the opposite of those above mentioned, in addi- 
 tion to which are, abundant secretions, organic diseases, and 
 particularly those of the organs of the nutritive functions. 
 
 168. Many hypothetical uses have been attributed to the 
 fat. Those which it really possesses, are local and general. 
 In fact, the uses of fat are in part purely mechanical, or of po- 
 sition, such as to lessen pressure, in the sole of the foot, in 
 standing, in the buttocks while sitting, and jointly with the 
 cellular tissue to fill up the hollows, and thereby give a round- 
 ness to the parts; thus we see those of women and children to be 
 the most so, they having most fat. It has been said, that the fat 
 served as a defence frpm cold, because this fluid is a bad con- 
 ductor of heat, and that the animals which inhabit cold coun- 
 tries, have a thick layer of it under their teguments. Admitting 
 this to be so, it is not by the surface of the skin, at any rate, 
 that the fat could preserve warmth. It has been asserted, but 
 without reason, that it lessened the nervous action, and the 
 action of the muscles, i. e. the muscular energy and sensi- 
 bility: in this case, cause has been mistaken for effect. The 
 fat has been thought to supple the fibres. Fourcroy, remem- 
 bering that this fluid contains an excess of hydrogen, thought 
 it destined to render the nutritive substance more nitrated, by 
 depriving it of a part of its hydrogen. Several authors, and 
 even Bichat himself is inclined to the opinion, have thought 
 that the fat might serve to oil the skin by a sort of porous 
 
138 GENERAL ANATOMY. 
 
 transudation: the sebaceous follicles are too well known at 
 present, to permit us to adopt this idea. The general uses of 
 the fat relate to nutrition. Previous to being assimilated, the 
 nutritive matter passes successively through various states; 
 fat is one of the forms it assumes. Moreover, this fluid may 
 be considered as an aliment in reserve: of this various exam- 
 ples are seen in animals. Insects for instance are nourished 
 by their fat while in their chrysalis state, and present the same 
 phenomenon a little time before their death. This is still 
 more strongly marked in the hybernating animals which sleep 
 during the winter, and are nourished by their fat only, until 
 they wake, at xvhich period they are excessively lean. The 
 foetus of the oviparous animals are nourished by the fat which 
 forms a great proportion of the yolk of the egg. 
 
 169. The adipose tissue and the fat, besides the differ- 
 ences of which we have spoken, present some morbid changes. 
 
 When the fatty tissue is divided, small drops of oil escape 
 and if the lips of the wound are maintained in contact, reunion 
 soon takes place; but the fat reappears in the place of reunion, 
 only, when the new cellular tissue has ceased to be compact. 
 The denuded fatty tissue becomes inflamed, the fat is absorbed ; 
 it then covers itself with a layer of organizable matter, which 
 becomes the base of the cicatrix or new skin that is formed 
 over the fat. 
 
 This tissue and the fat it contains sometimes accumulate in 
 great quanities, as is seen in obesity or polysarca. Individuals 
 have been seen in this state weighing five or six and some- 
 time eight hundred pounds. When the obesity is local, or 
 limited to a part of the body it is called Jipoma.* This dis- 
 ease may have its seat any where; it is most commonly seen 
 however under the teguments, and outside the serous mem- 
 branes. Tumours of this kind seated under the skin, have 
 been very improperly confounded with encysted tumours. 
 Their figure is round; when very voluminous they push up 
 and draw away the skin, and are then pediculated or pyriform: 
 
 * See Th. Ch. Bigot Dissert, sur les tumeurs graisseuses exterieur au pe~ 
 ritoine, etc. Paris, 1821. 
 
OP THE COMMON ADIPOSE TISSUE. 139 
 
 they have been found weighing from forty to fifty pounds. 
 On the exterior of the serous membranes their figure is gene- 
 rally ovoid, one of their extremities being attached to the 
 membrane, the other to the skin; outside the peritoneum this 
 tumour constitutes the fatty hernia or liparocele. The struc- 
 ture of the lipoma is analogous to that of the fat; the vesicles, 
 according to Munro, having the same volume as the latter, 
 being only more numerous. A cellular envelope similar to 
 that which surrounds the muscles, and which is sometimes so 
 dense as to approximate it to the fibrous membranes and the 
 cysts, is generally found round the tumour. This membrane 
 contains vessels which are tolerably apparent. The lipoma, 
 outside the peritoneum, when opened, sometimes exhibits the 
 aspect of the epiploon: generally speaking however these 
 tumours contain fewer vessels than others of the same volume. 
 
 Authors have spoken of fatty transformations of the mucles. 
 The following is what observation has taught me on this sub- 
 ject. In palsy the muscles often become perfectly white; 
 their fibres diminish in volume at the same time, and as this 
 alteration is chiefly observed in old persons, in whom the fat 
 is most abundant internally and as the part being at rest aug- 
 ments the quantity of this fluid, there results a fatty appear- 
 ance of the muscles that has been mistaken for a true fatty 
 transformation. But their proper fibrine is still to be found 
 in them, by submitting them to the action of alcohol, or of an 
 absorbant paper when boiled in water or exposed to the fire. 
 There is then merely a discolouration of the muscles, but no 
 fatty transformation. M. Vauquelin and M. Chevreul, in the 
 analysis they made of these muscles, obtained similar results. 
 Neither does this fatty transformation exist in the bones. The 
 marrow which occupies their interior may become more abun- 
 dant. The liver is sometimes the seat of a fatty transforma- 
 tion that has not been sufficiently examined. 
 
 Inflammations which occur in regions where the adipose 
 tissue is very abundant, have a peculiar tendency to terminate 
 in gangrene. This observation, which has long been made 
 upon the very fat animals, such as hogs and sheep, when they 
 are stung, is equally correct as relates to man, in whom wounds 
 
140 GENERAL ANATOMY. 
 
 and infiltrations stercoraceous or urinary ones particularly 
 in the fatty tissue, are followed by extensive gangrene. The 
 very small proportion of living parts contained in the adipose 
 tissue may account for these phenomena. Something analogous 
 may be seen in hernia epiploicoe: if considerable masses of 
 epiploon be left externally, this organ becomes gangrenous on 
 its surface, abundance of oil flows from it, and when in conse- 
 quence of this, its volume is considerably reduced, there re- 
 mains a mere red and very vascular mushroom, formed by 
 the cellular tissue intermediate to the fat and by the develop- 
 ment of the vessels. 
 
 Dr. Traill, of Liverpool, in a case of hepatitis, found in the 
 serum of the blood drawn by venesection, a remarkable quan- 
 tity of oil, nearly two parts and a half to the hundred of se- 
 rum. The cysts of the ovary frequently contain fat mixed 
 with hair, and sometimes teeth, but the alteration is in that 
 case very complex, and this is not the place to speak of it. 
 Biliary calculi are sometimes formed of a fatty matter called 
 cholesterine. Stercoraceous matters sometimes, also, contain 
 fatty substances, either intermixed, or in separate masses. 
 Ambergrease is a fatty substance that appears to come from 
 the intestine of the physeter macrocephalus. Certain cysts 
 of the genital organs and some hydroceles occasionally con- 
 tain brilliant particles that are nothing more than cholesterine. 
 This matter is also found, though less frequently, in morbid 
 tissues situated in other regions. The tumours called me- 
 liceris, steatoma and atheroma, which are considered as sub- 
 cutaneous, Chap, iii., contain a certain proportion of fatty 
 matter. 
 
 ARTICLE IT. 
 OF THE MEDULLARY, OR ADIPOSE TISSUE OF THE BONES. 
 
 170. The medullary tissue is a membranous, vascular and 
 vesicular tissue contained within the cavities of the bones. 
 It has received the names of marrow, medullary system, me- 
 dulla, meditullium, by a comparison with the pith of trees. 
 
OF THE MEDULLARY TISSUE OF THE BONES. 141 
 
 171. Duverney* has made it the subject of several ob- 
 servations: Grutzmachert and IsenflamJ have given detailed 
 descriptions of it. Every osteologist, and all those who have 
 paid attention to the adipose tissue, have also occupied them- 
 selves with the medulla. Havers, particularly, has well de- 
 scribed and figured its vesicular texture. Albinus has a beau- 
 tiful plate of it in his Jlnnotationes Academicx, the vessels 
 however are represented too large: Mascagni in his Prodromo 
 has also given a good figure of the medulla. 
 
 172. The marrow occupies the great medullary cavity of 
 the bodies of the long bones, the cellular cavities of the short 
 ones, of the extremities of the long bones, the thickness of the 
 wide bones, and even the pores of the compact subtance of the 
 bones. It is totally deficient in the sinuses and aerial cells of 
 the bones of the cranium. 
 
 173. Thefatwhich occupies the medullary canal of thebones 
 represents a cylinder moulded by the bony parietes of this ca- 
 nal, and is contained in a membrane called the internal or medul- 
 lary periosteum. This membrane, whose very existence some 
 have denied, while others considered it as being formed of 
 two layers, is composed of one single leaf, easily perceived 
 by an experiment, which consists in sawing a bone and ex- 
 posing it to fire or plunging it in acid : the membrane becomes 
 crisp, is detached from the bone and forms a distinct canal 
 whose tenuity is such, that without this precaution it is almost 
 impossible to see it. Its tissue can only be compared to that 
 of a cobweb. This membrane lines the interior of the bone 
 and appears to continue on to their extremities with the mar- 
 row that fills them. It sends off prolongations into the com- 
 pact substance and furnishes inside an infinitude of similar 
 parts, whose disposition, in general, resembles that of the 
 filaments and lamina that compose the cellular membranes. 
 
 * Memoires de PJlcademie des Sciences, 1700. 
 
 j- De ossium medulla. Lips. 1754. 
 
 t Ueber das Knockenmark, in beitrsege, &e. Von Isenflamm und Rosen- 
 muller B. II., Leipzig-, 1803. 
 
 Clopton Havers. OsteoL Nov. Lond. 1691. et Obs. nov. de ossibut. 
 Amstel. 1731. 
 
142 GENERAL ANATOMY. 
 
 These prolongations are supported by the filaments and lamina 
 of the reticular substance, in those places where it exists. 
 
 174. The composition of the medullary membrane, is prin- 
 cipally owing to the vessels that are ramified in the interior of 
 the canal, and which are supported by an extremely soft and 
 hardly visible tissue : this membrane, in this respect, greatly 
 resembles the pia-mater or the epiploon, and appears formed 
 like them, by the cellular tissue belonging to the sheaths of 
 the vessels. An artery and vein penetrate into the medullary 
 canal, and as soon as they have entered it, divide in two 
 branches, whose ramifications extend to the two extremities 
 of the bones, and communicate with the numerous and large 
 vessels of their extremities. The lymphatic vessels have been 
 followed to the entrance of the medullary cavities only. Suc- 
 cessful injections, on the contrary, show a multitude of colour- 
 ed filaments in the canal of long bones. The nerves of this 
 canal, whose existence has been denied, may be easily traced. 
 Soemmering, it is true, thinks that these nerves are destined 
 for the artery only. These nerves have been particularly 
 studied by Wrisburg and Klint. The medullary tissue is then 
 essentially composed, 1st, of an arterial and veinous net-work, 
 and probably of one of lymphatic vessels also: 2d, of a nervous 
 plexus destined either for the artery, or the artery and other 
 parts; 3d, of the cellular sheaths peculiar to these parts that 
 give out fibrilli, whose re-union form a sort of incomplete, 
 fringed, membrane. To this must be added vesicles, that are 
 very apparent, but in the recent subject only, as in others they 
 become much less distinct, owing to the rapidity with which 
 the marrow becomes fluid. These vesicles are in every re- 
 spect precisely similar to those of the adipose tissue in gene- 
 ral; they have the same volume, and the same connexion with 
 the blood-vessels, to which they appear appended. Grutzma- 
 cher, thinks that the texture of the marrow, and that of the fat 
 generally, is areolar like the common cellular tissue, and not 
 vesicular. The spongy extremities of the long bones contain 
 a great number of vessels; but their membrane is less dis- 
 tinct than that of the middle of the same bones. There ap- 
 pears to be vesicles there, similar to those of the medullary 
 
OF THE MEDULLARY TISSUE OF THE BONES. 143 
 
 membrane. The pores of the compact substance appear to 
 contain them also. 
 
 175. The fat of the bones is called marrow, in the medul- 
 lary canal, medullary fluid, in the spongy substance, and oily 
 juice in the compact substance. This fat is formed of the same 
 elements as all other fat, varying, however, in the propor- 
 tions, being more fluid ; it is also more highly coloured and 
 yellower. 
 
 176 The medullary membrane is sensible. Duverney has 
 well pointed out the experiment, which proves this property, 
 that Bichat has, perhaps, exaggerated a little, but which it is 
 wrong to question. If, in fact, in the generality of the amputa- 
 tions performed upon man, the impression caused by dividing 
 the bone is hardly felt, it is owing solely to the more violent 
 pain, resulting from the section of the skin which has preceded 
 it. But if in a living animal, we allow a sufficient interval to 
 elapse between the section of the teguments, and the lesion of 
 the marrow, so that the impression produced by the first, may 
 have time to be dissipated, a stylet introduced into the medul- 
 lary canal, produces a pain on the instant, which is testified by 
 the animal in various ways; it will easily be supposed, that 
 this sensibility resides in the membrane, and is foreign to the 
 marrow itself. The nerves in the bone accompanying the prin- 
 cipal medullary artery, if the bone is amputated above the en- 
 trance of this vessel, the remaining marrow no longer has any 
 communication with the nervous centre; it is to this disposi- 
 tion that is attributable, the difference of sensibility observed 
 by Bichat, between the centre, and the extremities of the me- 
 dullary cavity, and also to the fact, that the nervous threads 
 proceed in dividing themselves towards the two ends of this 
 cavity. The medullary tissue is gifted with an obscure con- 
 tractility, similar to that of the cellular tissue. The arteries, 
 which ramify in this membrane, secrete and deposite the fat. 
 
 177. The medullary membrane, according to Bichat, has 
 an early origin, pre-existent to the canal, it is filled with a car- 
 tilaginous substance, which afterwards gives place to the mar- 
 row, as fast as ossification advances. The most attentive ob- 
 servation has discovered no arteries, veins, nor medullary 
 20 
 
 
144 GENERAL ANATOMY. 
 
 membrane, in the cartilages: at a later period, the cavity of 
 the large bones is merely a narrow canal filled by the artery; 
 when the canal begins to enlarge, the artery throws itself on 
 the side, and fastens itself to the parietes; a viscid or gelatinous 
 substance is then contained in the canal; marrow is finally pro- 
 duced in it, but in small quantities ; in time, the canal increases 
 in size, and the marrow becomes more abundant. As respects 
 this tissue, there is no perceptible difference between the 
 sexes. This fluid, presents individual differences as relates to 
 quantity. In a state of ordinary plumpness, fat forms the 
 greater part of the substance contained in the medullary canal. 
 In eight parts of this substance, I have found seven of fat : the 
 remainder is formed by the vessels, water and albumen. In 
 lean subjects, on the contrary, the fat constitutes only a fourth, 
 or even a less proportion of the fluid contained in the long 
 bones : the remainder appears to me to be water, or at any rate 
 an evaporable substance, and albumen, or a coagulable sub- 
 stance. According to Camper, there is air, instead of marrow 
 in the cavities of the long bones of birds. 
 
 178. The functions of the medullary tissue, are to serve as 
 an internal periosteum, and as a reservoir for the fat: it is upon 
 it that those vessels ramify, which are directed outwards on 
 the one hand, to assist in nourishing the bone, and inwards, 
 on the other, to produce the secretion of the fat. The latter, 
 has the same uses as in other parts. Its local use is to fill up 
 those spaces which without it would exist in the bones. It 
 has been thought, and Haller and Blumenbach were of the 
 opinion, that it rendered the latter more flexible, and less fran- 
 gible; but the bones of children, deprived of fat, are, however, 
 less frangible than those of adults, while the bones of old peo- 
 ple, in whom this fluid is so very abundant, are in general very 
 fragile. Those who have advanced this opinion, found it upon 
 the fact, that combustion deprives the bony substance of all its 
 solidity; it is evident, however, that in this case it is not the 
 oil only which it loses, but the animal matter also, on which 
 depended their solidity. The same authors add, that by boil- 
 ing the earthy residuum, obtained by the combustion, in oil 
 or gelatine, its solidity, to a certain degree, is restored; but a 
 
OP THE MEDULLARY TISSUE OP THE BONES. 145 
 
 peculiar compound is thus formed, a kind of stucco* that has 
 no resemblance to bone. Haller and other physiologists have 
 also thought that the marrow served for the reproduction of 
 bone, and the formation of callus particularly. Observation, 
 however, shows us, that fractures heal so much the more 
 readily as the patient is young, and the less marrow there is, 
 or the less fat the marrow contains. Duverney, and others, 
 have considered the marrow as necessary to the nutrition of 
 the bones; is a sufficient proof of the inadmissibility of this 
 opinion, that many animals have none, as birds, and that deer's 
 horns are deprived of it, that this fluid does not exist in in- 
 fancy, and that the bones are formed before the marrow. The 
 marrow has also been regarded as the reservoir of latent calo- 
 ric, and of electricity. Marrow does not serve to lubricate 
 articulating surfaces, for the synovia exists in many places 
 where there is no marrow. 
 
 179. The marrow undergoes some morbid changes.* 
 While the bone is consolidating in fractures, the fat disappears 
 in the medullary canal; the cellular tissue of this canal becomes 
 compact, as in other cases of solution of continuity, and ends 
 in ossification : this last fact, observed by Bichat, has since been 
 verified by several observers, when the consolidation is per- 
 fect, the medullary membrane re-assumes its properties. 
 
 After amputation, the same phenomena are observed in the 
 marrow, as in other wounds, affecting the fatty tissue : the oily 
 matter disappears, and a cellular and vascular layer is formed 
 at the truncated extremity of the bone which finally closes. 
 The marrow is destroyed in the sequestra, and does not appear 
 to be re-established after they are taken out; at least it has ne- 
 ver been known so to do; perhaps the state of the parts has 
 never been examined a sufficient length of time after the ter- 
 mination of the disease. 
 
 The medullary membrane is susceptible of inflammation: 
 it is probable to this and its consequences, that internal necro- 
 sis is to be attributed. It is equally probable, that pains in the 
 bones depend on this inflammation. A peculiar induration of 
 
 * See Moignon. Teutamen de morbis ossium medullas. Paris et Lugtf. 
 Ann. iii. 
 
146 GENERAL ANATOMY. 
 
 the medullary membrane is observable in rachitis which has 
 not been described. 
 
 Among the affections peculiar to this membrane, spina ven- 
 tosa is the most remarkable. According to my own observa- 
 tions and those of several others, there are two and even three 
 distinct species of this disease. The considerable develop- 
 ment of the bone arises from the extraordinary growth of the 
 altered medullary membrane; but at one time the alteration 
 in the marrow consists in a carcinomatous degeneration in a 
 true, soft cancer; at another the tumour is fibrous and carti- 
 laginous: in some cases, particularly in children, the bone 
 enlarged in the middle, contains a highly vascular red sub- 
 stance whose nature has not been well determined this variety 
 is particularly observed in the bones of the metacarpus, of the 
 metatarsus and of the fingers. Spina ventosa particularly affects 
 the long bones of the limbs: in the femur it is generally the 
 inferior part of the bone that is diseased, in the humerus, the 
 superior. I have taken away the superior third of the fibula 
 in a young woman, in a case of spina ventosa, that had en- 
 larged the head of the bone to the size of the patient's fist. 
 Tumours of this nature have been described by Vignarous 
 under the name of bony steatoma, and by Sir A. Cooper under 
 that of medullary exostosis. 
 
OP THE SEROUS MEMBRANES. 147 
 
 CHAPTER II. 
 
 OF THE SEROUS MEMBRANES. 
 
 180. The membranes, membranae, are soft, broad and thin 
 parts that line the cavities, envelop the organs, enter into the 
 composition of a great number of them and constitute others: 
 they differ greatly from each other in their texture, composi- 
 tion, action, &c. 
 
 181. The serous membranes, membranx serosse, vel suc- 
 cingentes, so called because they contain a great many serous 
 vessels in their thickness, are humected by a liquid analogous to 
 the serum of the blood, and because they furnish tunicks to many 
 organs, form a system or numerous genus of membranes closed 
 on all sides, adhering by one surface to the surrounding parts, 
 loose and contiguous to themselves on the other, serving to 
 isolate certain parts, to facilitate their movements, and result- 
 ing from a very simple modification of the cellular tissue. 
 
 182. Confounded for a long time with the parts to which 
 they are attached, the serous membranes have been particularly 
 distinguished from other parts and studied in their ensemble 
 by Bonn,* by Munro,t and particularly by Bichat.J 
 
 183. The serous system comprehends membranes which, 
 by their numerous points of similarity, form a very natural 
 genus, in which, however, there are sufficient differences to 
 mark several divisions expedient. In relation to their situa- 
 tion, and to the more or less unctuous liquid which humects 
 them, they are divided into serous membranes, properly so 
 called, or serous membranes of the splanchnic cavities, and 
 synovial ; the latter are again divided into those of the articula- 
 
 * Be continuationibus mtmbmnarum. Amst. Batav. 1763. 
 \ .7 description of all the bursae mucosse, 6?c Edinb. 1788. 
 t Traite des Membranes. Paris, an. viii. 
 
148 GENERAL ANATOMY. 
 
 tions, those of the tendons and those which are subcutaneous. 
 We must first examine the characters common to all the genus, 
 and then those of the species. 
 
 SECTION I. 
 
 OF THE SEROUS MEMBRANES IN GENERAL. 
 
 184. All these membranes consist of bladders closed on all 
 sides: there is no other exception to this general disposition, 
 than the opening by which the peritoneum communicates 
 with the genital organs in women, the continuity of these or- 
 gans themselves being interrupted between the ovary and the 
 commencement of the oviduct or fallopian tube. The result 
 of the general conformation of the serous membranes, is, that 
 the fluids they contain are entirely isolated, and that their 
 membranes are only permeable by the vessels that ramify in 
 their thickness, and not like the cellular tissue, by areolae freely 
 communicating with each other; this conformation presents, 
 however, some secondary forms or varieties. Some of these 
 membranes which are as simple as possible, resemble an am- 
 pulla or bladder; they are called vesicular. Others constitute 
 sheathing envelopes that surround certain parts such as the 
 tendons, ligaments and the blood vessels; and as they are not 
 pierced so as to allow these parts to pass, but are reflected at 
 their two extremities and so form a double sheath, they have 
 received the appellation of vaginiform. This disposition is 
 one of the most usual. There are some however that are still 
 more complex; they are the enveloping serous membranes, 
 those which more particularly merit the name of succingentes: 
 these latter surround the organs except at one single point of 
 their surface, about which they are reflected on to the parities 
 of the cavity which contains them, and are thus divided in 
 two portions, of which one forms an envelope for the organs, 
 and is called the visceral layer, or tunic, while the other 
 which lines the parietes, constitutes the parietal layer. The 
 
OF THE SEROUS MEMBRANES in GENERAL. 149 
 
 different forms we have just examined, are often united in 
 the same membrane. In the enveloping serous membranes, 
 like in those which are found about the heart, lungs and testi- 
 cles, there is always a spot on the surface of the organ deprived 
 of this serous envelope; it is through this spot that the vessels of 
 the organs penetrate, or that the organ itself is attached to the 
 surrounding parts. This part, freed from organs covered with 
 serous membranes, is sometimes considerable, at others, very 
 narrow. In some instances the viscus is removed from the 
 parietes which contain it, arid is attached or suspended by a 
 fold of the serous membrane which forms what is called a 
 bridle or membranous ligament: this disposition is no excep- 
 ception to what we have just said. There is always a part of 
 the organ, not covered by' the membrane throughout the whole 
 extent of the surface to which the fold formed by the latter 
 adheres. Besides this first kind of folds or plaits, the serous 
 membranes present prolongations, that float more or less loose- 
 ly in the cavity they form, and which most commonly depend 
 on their visceral layer, but which sometimes belong to the 
 others : the epiploon, the appendicoe epiploicoe for the perito- 
 neum; the fatty plaits observed in the pleura on the sides of 
 the mediastinum, for this latter membrane; thesy no vial fringes 
 for the articulating capsules, are all examples of these pro- 
 longations. These latter always contain cellular tissue, gene- 
 rally fatty, within their substance: it is here also that the 
 membrane presents most vessels. 
 
 185. All the serous membranes have two surfaces, one 
 free, the other adherent. The latter is flaky, and holds to the 
 cellular tissue, to ligaments, tendons, cartilages, &c. Its de- 
 gree of adherence to these different parts is more or less great: 
 a loose cellular tissue sometimes produces it, while elsewhere 
 as on the cartilages, it adheres closely. There is a multitude 
 of intermediate degrees between these two extremes, as may 
 be observed when adhering to ligaments, muscular fibres, 
 tendons, &c. The free surface of the serous membranes is 
 everywhere contiguous to itself: it is the interior of a kind 
 of bladder that these membranes resemble. This surface, at 
 the first glance, appears perfectly smooth and polished: but 
 
150 GENERAL ANATOMY. 
 
 microscopically examined, it presents manifest villosities: for 
 this reason they have been styled, the simple villous mem- 
 branes. This surface is constantly humected by a liquid. 
 
 186. The serous membranes are generally of a whitish 
 colour, which their transparency renders scarcely sensible r 
 glistening on their free surface, extremely thin yet tolerably 
 strong, more so in fact than the cellular tissue would be if re- 
 duced into lamina of an equal tenuity; they are commonly 
 slightly elastic. 
 
 187. They appear, at first sight nearly homogeneous: al- 
 most always, however, a fibrous appearance, more or less 
 marked, may be observed in various parts of their extent. 
 When torn by distension, they first become loosened, and then 
 reduce themselves into little intermixed, intercrossed, and, as 
 it were, interwoven filaments. Their nature appears very 
 analogous to that of the cellular tissue, from which they only 
 differ by their greater density and the distinct cavity they 
 represent. Between the cellular tissue and the serous mem- 
 branes, there exists a sort of insensible gradation, and the most 
 simple of the serous membranes still partake largely of the 
 nature of the cellular tissue. The very loose cellular tissue 
 in which inflation develops large ampulloe, as that of the pre- 
 puce, that which exists between the great moving muscles 
 and the subcutaneous synovial bursae, constitute a transition 
 between the two tissues. Very numerous white vessels enter 
 into the composition of these membranes. Injections and 
 inflammation penetrate the first with a coloured liquid; the 
 second, the blood, in these vessels render the latter very ap- 
 parent: their number then appears very considerable. We 
 must not, however, confound the vessels peculiar to the serous 
 membrane with those that belong to the subjacent cellular 
 tissue, and which might be supposed to exist in the membrane 
 itself, on account of its transparency. In the peritoneum, for 
 instance, the inflammation must last for a long time to cause 
 the blood to penetrate beyond the sub-serous cellular tissue; 
 and on a slight observation one would be tempted to think it 
 was the peritoneum itself rendered vascular by the disease. It 
 is the same with injections; it is only when they are extreme- 
 
OF THE SEROUS MEMBRANES IN GENERAL. 151 
 
 ly thin that they penetrate into the membrane itself. The 
 nerves of the serous membranes are not known. 
 
 188. The liquid contained in these membranes is not the 
 same in all; it resembles however more or less the serum of 
 the blood or blood deprived of its colouring matter. It con- 
 tains, in general, water, albumen, an incoagulable matter that 
 may be considered a sort of gelatiniform mucus, a fibrous 
 matter and soda. We shall see hereafter the difference pre- 
 sented by this liquid in the various species of the serous 
 membranes. 
 
 189. The serous membranes, during life particularly, are 
 highly extensible and retractile, as is seen in dropsies and 
 after the disease is cured: but their enlargement is not always 
 the result of their extensibility; their folds disappear, which 
 being gradually developed, serve to aid the increase of the 
 membrane. Another cause which assists in this augmenta- 
 tion of volume, is the sliding of which this is susceptible, the 
 species of locomotion it experiences when it is distended in 
 one part only, as is particularly seen in hernia. There appears 
 also in some cases a real increase of nutrition, which contri- 
 butes to the production of this phenomena : this augmentation, 
 with the other causes of ampliation is manifested in pregnan- 
 cy. These phenomena are not all equally marked in the 
 different species of serous membranes: the peritoneum pre- 
 sents them in the highest degree; they are much less so in the 
 synovial membranes, the articulating ones particularly, which 
 partly arises from the less extensible nature of these mem- 
 branes, and from their having fewer folds, and above all from 
 their connexions which do not permit them to displace them- 
 selves with the same facility. When the distension has ceased 
 they gradually return to their original state, but if it has pro- 
 ceeded to a very relaxed state, traces of it always remain. 
 
 190. The force of formation, tolerably well developed in 
 the serous membranes, is less so in them, however, than in the 
 free cellular tissue. Their mobility is very limited, extending 
 only to the feeble degree which constitutes tonicity. But if 
 irritation does not occasion in them any perceptible move- 
 ments, it develops sensibility there: in fact these membranes 
 21 
 
152 GENERAL ANATOMY. 
 
 become very sensible and generally, in inflammation trans- 
 mit painful impressions. 
 
 191. All the serous membranes are the seat of the constant 
 deposition and absorption of a serous liquid in their cavity or in 
 their free and contiguous surface. The great extent of these 
 membranes, taken together, gives great importance to this dou- 
 ble function. The matter of this secretion, like all the others, is 
 brought by the vessels into the thickness of the membrane, 
 and particularly into its most vascular points, the fringed 
 prolongations: by what way the secreted matter leaves the 
 vessels and passes into the cavity, is not exactly known. Se- 
 creting glands have been supposed for all these membranes, 
 either in their vicinity or in their own thickness but no such 
 glands exist. Transudation by organic pores, has also been 
 supposed; but without exactly knowing the mode in which 
 the perspiratory secretions are performed, we know that tran- 
 sudation takes place in the dead body only, and then even 
 some time after death. The liquid is also continually absorbed 
 by the membrane, in the thickness of which it re-enters the 
 vessels. While the deposition and absorption remain in equi- 
 librium, the serous membranes are simply moistened on their 
 surfaces. The augmentation of the secretion or the diminu- 
 tion of the absorption, gives rise to an accumulation called 
 dropsy. 
 
 The secreted liquid has local uses and general uses: locally, 
 it serves to preserve the separation between the two contiguous 
 layers of the serous membranes and to facilitate the motion 
 of the organs over one another; generally, it is probable, that 
 the nutritious matter thus alternately deposited and taken up 
 becomes more perfectly assimilated, previous to its employ- 
 ment in nourishing the organs. 
 
 192. The action of the serous membranes, in health and 
 in disease particularly, is closely united with those of the 
 other organs. Thus, when they are diseased, the functions 
 of the organs they invest are more or less disturbed, and this 
 disturbance extends to a distance, and often to the whole or- 
 ganism; in the same way, affections of other organs particu- 
 larly those of the tegumentary membranes, of the circulating 
 
OF THE SEROUS MEMBRANES IN GENERAL. 
 
 organs, and of the glands, frequently derange their functions; 
 the affections of the organs they invest always produce a cor- 
 responding one in them, more or less evident; on the one hand, 
 the cavity they form establishes a complete isolation between 
 the parts on which their opposite portions are reflected; on 
 the other, the continuity and extent of these membranes, easily 
 give rise to very extensive affections. 
 
 193. At its origin, about which however little is known, 
 the serous system is very soft: in the embryo the abdominal 
 viscera seem covered with a mere viscid and liquid varnish. 
 The serous membranes are very thin in the fretus, and in ge- 
 neral less adhesive, on account of the softness of the cellular 
 tissue which unites them to the neighbouring parts, so that 
 they are easily separated from these latter: in the articulating 
 cartilages, however, and in the albuginea of the testicle, the 
 adhesion is almost as great as at a later period. We are com- 
 pletely ignorant whether or not these membranes, whose essen- 
 tial character is the interruption of continuity they establish 
 between the parts, are at first a soft cellular tissue, continuous 
 and without an internal cavity, as is affirmed by some anato- 
 mists, who admit that in the beginning, there exists a general 
 continuity of all the parts ; among the bones, for instance. The 
 liquid of the serous membranes is at first very thin; some of 
 these membranes, those of the splanchnic cavities, present in 
 the foetus remarkable differences of conformation. In old age 
 the serous membranes undergo various changes. 
 
 194. The conformation of an accidental serous tissue is 
 frequently observed; its reparatation or reproduction takes 
 place in wounds of the serous membranes, which reunite when 
 their edges are in direct contact; observation has shown the 
 opinion of the ancients, who did not believe this kind of wound 
 susceptible of reunion, to be totally void of foundation. When 
 these wounds are attended with loss of substance, or when 
 there is a separation of their edges, the space is filled up by a 
 new membrane, a true cicatrix; this appears a little thinner 
 and more extensible than the surrounding membrane. 
 
 195. The liquid contained in the cavity of the serous 
 membranes is susceptible of accumulation either from the ab- 
 
154 GENERAL ANATOMY. 
 
 sorption being diminished or the exhalation being increased: 
 this accumulation produces various dropsies. The liquids 
 formed in the latter, presents various qualities, particularly if 
 there is inflammation. This fluid sometimes contains more 
 animal matter than is found in a state of health, at others 
 less: sometimes the proportion of this matter is the same as 
 in that state. Generally speaking, the serosity of dropsies 
 resembles the serum of the blood, except in having a less pro- 
 portion of albumen. There is one point of pathological ana- 
 tomy to which sufficient attention has not been paid; that is 
 the dropsies which do not appear to depend upon an altera- 
 tion of the serous membranes or of the organs of respiration 
 and circulation, and which for this reason have been regarded 
 as general affections, are often preceded and accompanied by 
 a flow of urine containing a great proportion of gelatine and 
 albumen, a substraction of animal matters which alter the 
 composition of the blood, which renders it more watery and 
 which is owing to an alteration of the kidney and its function. 
 This flux sometimes also accompanies dropsies with a local 
 affection of another viscus. * 
 
 196. Inflammation of the serous membranes, which is 
 a very frequent occurrence, produces in these membranes, 
 changes in their tissue and in their secretions. The membrane 
 becomes vascular at first in its external cellular tissue, and 
 after a while in its own thickness; its vascular fringes and 
 villosities are better marked, and finally become more promi- 
 nent and very thick. If the inflammation continues for a cer- 
 tain time, the membrane becomes thickened and loses its 
 transparency; this thickening, however, which appears very 
 great, is generally in appearance only and is foreign to the 
 membrane itself. Besides the interstitial arrangement which 
 gives rise to this alteration, a secretion takes place in the ca- 
 vity of the membrane itself; the secretion however, is at first 
 suspended, afterwards to be renewed with a change of charac- 
 ter. The liquid poured out, is, as the case may be, either a 
 simple and abundant serum, but not materially altered, or a 
 
 * See T. Blackall, Observations on Dropsies, etc. London, 1813. 
 
OF THE SEROUS MEMBRANES IN GENERAL. 155 
 
 whitish lactescent fluid, or containing albuminous and fibrin- 
 ous flakes; sometimes, though rarely, the serum is bloody; 
 finally, pus is to be found in it, having all the properties of 
 that produced in the cellular tissue. Besides these effects of 
 inflammation, there are others which are very remarkable. 
 
 197. The false membranes, the pseudo membranae, are 
 not peculiar to the serous membranes, but are frequently found 
 there. They consist in the concretion, under the form of a 
 membrane, of the product of the secretion of the membrane, 
 inflamed to a certain extent. This product, similar to the or- 
 ganizable matter which determines the adhesion of the lips of 
 wounds, is at first thrown in separate drops on the free surface 
 of the membrane; these drops, by their multiplication and 
 extension, generally meet, forming first a net-work, then an 
 entire surface. Most commonly the same thing takes place 
 on the opposite side of the membrane and the latter generally 
 remaining in contact with the former, the false membrane oc- 
 casions the agglutination of the two parts, previously contigu- 
 ous : this is the first degree of adhesion, the gelatinous adhe- 
 sion of some, and the plastic adhesion, adherence couenneuse 
 of others; I prefer calling it agglutination. At one time the 
 agglutinating matter merely forms a thin layer interposed be- 
 tween the approximated surfaces, at another, it is so abundant, 
 that it fills and distends the serous cavity. 
 
 Organic adhesions of the serous membranes, are a frequent 
 result of the formation of false membranes. The organizable 
 matter of the agglutination, is converted into cellular tissue, 
 in which are formed ramifying canals, which gradually acquire 
 the vascular structure, (chap, iv.) and which end by commu- 
 nicating with the vessels of the inflamed membrane. Several 
 of the first observers, who saw the vessels of the adhesions, 
 mistook them for vascular villosities, prolonged from the old 
 membrane into the matter of the false one. J. Hunter and 
 M. Ev. Home, have observed the contrary, a fact, the truth 
 of which I have several times proved. By pricking, at ran- 
 dom, a recent adhesion with a tube filled with mercury, we 
 can inject the ramifying canals, whose largest part or trunk, 
 corresponds with the centre of the adhesion, and whose branches 
 
156 GENERAL ANATOMY. 
 
 diverging in opposite directions, like those of the vena porta, 
 are directed towards the serous surfaces, without always ar- 
 riving there, and without the latter presenting any well marked 
 villosities. In time, this disposition changes, as soon as the 
 canals have communicated with the old vessels, the adhesion be- 
 comes more and more vascular in the vicinity of the membrane, 
 and less and less in its centre. Organic adhesions of the serous 
 membranes, have not always the same form, they consist, gene- 
 rally in bridles or cords, larger at the adhering extremities, 
 and smaller in the centre which is free; at other times, there is 
 a great number of filaments nearly similar to the bridles; in 
 other cases, the adhesions are so multiplied, that the two parts 
 of the membrane are confounded, and seem to be replaced by 
 the cellular tissue. The texture of the adhesions, as seen in 
 the bridles, is that of the serous membranes ; they form a sort 
 of smooth sheath, filled with cellular tissue containing some 
 vessels. These adhesions are on the one hand so frequent, 
 and on the other so regularly organized, that many of the an- 
 cient physicians took them for natural ligaments, and that 
 among the moderns, Tioch has found some of them in the 
 pericardium, and Bichat in the pleura, that appeared to them 
 to belong to an original conformation. 
 
 The bridles or bands which form the adhesions, lengthen as 
 they harden, it is even probable that in the end, their centres are 
 completely absorbed; what inclines us to this belief, is, that in 
 examining the parietes of the abdomen, soon after wounds of 
 this part, we generally find the intestine adhering to the place 
 of the wound, while at a more distant period, the adhesion is 
 merely formed by a bridle, which at last becomes itself very 
 thin; and finally, that if we observe the disposition of the parts, 
 at the end of a very long period, we find no adhesion what- 
 ever. These different degrees, were all found in the body of 
 a patient, I dissected, who was affected with melancholy, and 
 who had stabbed himself with a knife twelve or fifteen times, 
 at different periods of his life. 
 
 198. The serous membranes undergo several transforma- 
 tions, or to speak more correctly, are the seat of various acci- 
 dental productions. Fibrous, cartilaginous, fibre-cartilaginous. 
 
OF THE SEROUS MEMBRANES IN GENERAL. 157 
 
 and even bony plates, are frequently observed in their thick- 
 ness, particularly in the pleura, which sometimes forms a sort 
 of shield in consequence of chronic pleurisy. These plates, 
 are generally, it is true, subjacent to, or laid over them. 
 
 Free or pediculated concretions have their seat in the inte- 
 rior of these membranes. They are found, more particularly, 
 in the articulating serous membranes, sometimes, however, in 
 those of the tendons, and even in the splanchnic cavities. They 
 are at first external to the membrane, and afterwards pushing 
 it gradually before them, they project into its interior, where 
 they present a wide and short base, and at a later period, a 
 pedicle which becomes longer and longer, until finally break- 
 ing, they become perfectly free in the cavity of the mem- 
 brane. Such is the true mechanism of the formation of these 
 bodies, that have been taken for true concretions, when they 
 had not been observed in their different stages of development. 
 The consistence of these bodies varies: sometimes they are 
 very soft and albuminous,but most commonly they are fibrous, 
 cartilaginous or bony. 
 
 The serous membranes participate in the degenerations 
 common to all the tissues; they appear, also, to be subject to 
 some that are peculiar to them. 
 
 199. Vices of conformation are to be observed in some of 
 these membranes, as in the arachnoid membrane of the anen- 
 cephalous foetus, in the peritoneum and vaginal tunick, when 
 the canal of communication between these two membranous 
 sacs subsists after birth. A kind of supernumerary sacs have 
 been found in the peritoneum: Neubauer gives some examples. 
 Acquired vices of conformation are also peculiar to a small 
 number of these membranes, and belong to special anatomy. 
 Hernia is one of these vices. 
 
 200. Cysts may with propriety be described along with 
 the serous membranes: it is in fact with this genus of organs 
 that they have the greatest resemblance. They resemble, in 
 general, like all the parts comprised in the serous system, a 
 pocket or membranous cavity, closed on all sides, adherent on 
 one surface, free on the other, and in contact with a liquid 
 which fills it: they are commonly of a globular form; their 
 
1 58 GENERAL ANATOMY. 
 
 volume varies from that of a grain of millet to that of the dis- 
 tended abdomen; here we find them isolated, and there several 
 grouped together and communicating with each other; their 
 external surface is floculent, cellular, sometimes having laminae, 
 or even a fibrous layer; sometimes this surface is lined with a 
 natural membrane which they have encroached upon in sally- 
 ing towards a surface; their internal surface is smooth and 
 polished: the thickness varies, and is in general less in the 
 cysts of the organs, than in those of the free cellular tissue; it 
 is also greater or less in different parts of the same cyst; the 
 consistence varies from that of a barely concrete liquid, to that 
 of the serous and even of the fibrous tissue; it is the same with 
 their adhesions which are sometimes very close, and at others 
 seem to be a simple agglutination: there are no apparent ves- 
 sels on their free surface. 
 
 The liquid they contain is not less various. At one time, 
 we find it a serum, either limpid or more or less thick like 
 albumen, variously coloured; at another it is fat, either fluid, 
 or in particles forming cholesterine; in some cases it is mucus 
 or a viscid substance, which, instead of coagulating by heat, 
 evaporates almost wholly, leaving but very little residuum; 
 in others it is a mixture of mucus and albumen, or a blackish 
 matter resembling chocolate, sometimes even pure blood; at 
 others hydatid worms; sometimes crystallized saline sub- 
 stances : a concrete substance has also been found there, re- 
 sembling caoutchouc. 
 
 The cysts are in a state of repletion that may be compared 
 to the dropsies of the serous membranes : they are the seat, 
 however, of a continual secretion and absorption ; they disap- 
 pear in certain cases, persist in some, and continually increase 
 in others. 
 
 Different theories have been proposed to explain the forma- 
 tion of cysts. Some authors regard them as membranes of a 
 new formation which are developed round an originally exist- 
 ing substance; others again, on the contrary, think they are 
 pre-existent to the matters they contain, whether they be form- 
 ed by the distended cellular tissue, or owe their production to 
 the dilated lymphatics. It is difficult to say, exactly, which of 
 
OF THE SEROUS MEMBRANES IN GENERAL. 159 
 
 the two opinions are right. There are cases that favour each 
 of them. Certain tissues that are classed with the cysts, arc 
 evidently pre-existent. In this class we may place the sub- 
 cutaneous wens, which are nothing more than sebaceous folli- 
 cles, considerably enlarged, and not accidental sacs, the cysts 
 of the ovary, which appear to depend upon the extraordinary 
 development of the vesicles of that organ, the cysts of the testi- 
 cular cord of man, or of the labia pudendi of woman, which are 
 the remains of the tunica vaginalis, &c. Another genus of 
 cysts, are, on the contrary, formed consecutively; such are 
 those which follow the effusion of blood which occur in the 
 brain, those which are developed around a foreign body, &c. 
 In other cases it is very difficult to determine the mode and 
 origin of cysts. It is very likely, however, that all true cysts 
 are membranes of a new formation, determined or not by an 
 evident inflammation. The cysts are, besides, subject to all the 
 affections of the serous membranes, to all the varieties of in- 
 flammation, to accidental productions either analogous or mor- 
 bid. They have been found every where, in bones and car- 
 tilages, perhaps, excepted. 
 
 The new cellular membranes, which envelop accidental, 
 analogous, or morbid accidental productions, and foreign bo- 
 dies, are generally confounded with cysts. These envelopes 
 are not like the cysts and the serous membranes, inhalant and 
 exhalant surfaces: they often line the cysts. Their consistence 
 varies : they are also always parts of a new formation. 
 
 Between the cysts or serous vesicles, holding to the cellular 
 tissue by their external surface, and the hydatids, there are 
 insensible transitions, between which it is very difficult to 
 draw a well denned line of demarcation. Thus the little se- 
 rous vesicles, that are so often found in the plexus choroides, 
 those which are sometimes seen at the fringed extremity of 
 the fallopian tubes ; those which I have frequently seen in the 
 vegetation of the nasal and uterine mucous membranes, all evi- 
 dently appear to belong to the cysts. The hydatid or cluster- 
 ed mole appears to me to belong to the same genus, yet a very 
 able physician and naturalist,* refers it to the genus acephalo- 
 
 * See li. Cloquct. Faune des medians, torn. i. Paris 1822. 
 22 
 
160 GENERAL ANATOMY. 
 
 cyst. The three species of simple acephalocysts themselves, 
 whose animality is yet doubtful, approximate in a certain de- 
 gree to the cysts. I have taken from under the skin of the 
 neck, and several times from under the skin of the mammae, 
 acephalocysts of these species that were single, not encysted, 
 not adhering, it is true, but agglutinated to the cellular tissue. 
 Most commonly we find one or the other of the three species 
 of simple acephalocysts, assembled in great numbers and free, 
 in a distinct cyst. 
 
 A modern physician* has attributed the origin of tubercles, 
 of all tumours, and even of all foreign bodies suspended or free 
 in the serous and synovial cavities, to the formation, develop- 
 ment and transformations of the hydatids, or hydatiform cysts 
 of which we have been speaking. 
 
 After having given the general history of the serous system, 
 we must describe in succession the various species which com- 
 pose it. 
 
 SECTION II. 
 
 ARTICLE I. 
 OF THE SUB-CUTANEOUS SYNOVIAL BURS.E. 
 
 201. The synovial or mucilaginous sub-cutaneous bursae, 
 bursas mucosas sub-cutanese^ had not been described by anato- 
 mists. Some pathologists, and particularly Gooch, Camper, 
 and lately M. Asselin, have spoken of their dropsy, and while 
 treating of this, Camper has a word upon their healthy state. 
 I have examined and described them for a long time in my lec- 
 tures; I have also mentioned them in the additions to the gene- 
 ral anatomy of Bichat, and in the Dictionnaire de Medecin. 
 
 202. The synovial bursae, whose rudiments are partly seen 
 in the loose and very extensible cellular tissue, which exists 
 between all the very moveable parts, are found under the 
 skin, wherever that membrane covers parts that exercise great 
 
 * See J. Baron. An inquiry &c. on tuberculous diseases. London, 1817. 
 
OP THE SUB-CUTANEOUS SYNOVIAL BURS.E. 161 
 
 and frequent motions; as between the skin and the patella, the 
 olecranon and the skin, on the trochanter, on the acromion, 
 before the thyroid cartilage; sometimes behind the angle of 
 the jaw; always between the skin and projecting side of the 
 metacarpal and metatarsal articulations, and between those of 
 the first and second phalanges. All these latter are generally 
 confounded with the neighbouring tendons. 
 
 In order to have a good view of these membranes, we must 
 fill them with air. It is then seen that they form an obround, 
 multilocular cavity, that is, a cavity divided by incomplete, 
 but closed partitions, the air blown into it, remaining shut up 
 there, and not passing into the surrounding cellular tissue; the 
 walls of the cavity they form are very thin and weak. 
 
 Their texture is very simple, like those of the serous mem- 
 branes generally, and appears to differ from that of the cellular 
 tissue, only by a little greater density. There are but very few 
 vessels in the thickness of these membranes: their free and 
 contiguous surface is humected by an unctuous or mucilagi- 
 nous liquid, in such small quantities, as to preclude the possi- 
 bility of its being properly examined. 
 
 The local use of these membranes and the unctuous liquid 
 they contain, is evidently to facilitate the motion of the bones 
 under the skin. 
 
 These bursae are developed at a very early period ; they exist 
 at the time of birth, and are then easily perceived on account 
 of the greater abundance of the liquid that moistens them. 
 
 Their development augments in proportion to the exercise 
 of the parts they cover; that of the acromion, for instance, be- 
 comes more apparent in individuals who carry burdens on the 
 shoulder; that of the knee is most developed in those who are 
 habitually kneeling. 
 
 203. They are formed accidentally, in those cases where 
 the skin exercises accidental rubbings. M. Brodie speaks of 
 a gibbosity, on which one was developed in consequence of 
 the continued sliding of the skin: the same thing is observable 
 in club-foot in the spot where the skin rubs against the salient 
 side of the tarsus; and again, the same result takes place after 
 
162 GENERAL ANATOMY. 
 
 amputation of the thigh, between the end of the bone and the 
 cicatrix. 
 
 Dropsy of the sub-cutaneous synovial bursae, constitutes hy- 
 groma, an affection known to the ancients, that is observed 
 particularly in the knee, before the patella of persons who ha- 
 bitually rest on it, such as priests, nuns, the washerwomen of 
 certain countries, servants who scrub in that posture, sweeps 
 &c. and that is also occasionally, but less frequently seen in the 
 other membranes of the same species. Hygroma may acquire 
 considerable volume. It sometimes suddenly disappears with- 
 out any known cause, or after medicinal applications. I have 
 sometimes punctured it, and withdrawn a viscid serum. A 
 stimulating injection, after the fluid is abstracted, often pro- 
 duces a mutual adhesion of the walls, and an obliteration of the 
 cavity. 
 
 The sub-cutaneous synovial bursae are susceptible of inflam- 
 mation, of suppuration, and the formation of large abscesses, 
 either from reiterated pressure, or from injections. 
 
 ARTICLE II. 
 OF THE SYNOVIAL MEMBRANES OP THE TENDONS. 
 
 204. The synovial membranes of the tendons, membranse 
 mucosse teridinum, are serous membranes, moistened with an 
 unctuous fluid, annexed to the tendons in the places where 
 they rub against the neighbouring parts. 
 
 They have received the improper names of bursse, bladders, 
 capsules, of mucous, mucilaginous, synovial sheaths, &c. They 
 have long been known: Vesalius and A. Spigel mention some 
 of them. A certain number have been accurately described 
 by Albinus. Jankius was the first who gave a general descrip- 
 tion of them; he was acquainted with sixty pairs. Camper 
 was the first who gave a figure of one of these membranes. 
 It is to our celebrated Fourcroy,* as well as to Munro,t that 
 
 * Hist, de 1'Acad. R. des Sciences. Palis, 1785, 1788. 
 f Jl description, etc. with tables. 
 
OF THE SYNOVIAL MEMBRANES OF THE TENDONS. 163 
 
 this part of anatomy is most indebted. Koch* has well de- 
 scribed these membranes, not in man only, but in several 
 animals. Gerlacht was the first who described and figured, 
 well, those that are found in the neck and head, llosenmul- 
 lerj: has given a work on them, augmented by that of Munro. 
 Mascagni has given a good figure of one of these membranes 
 in his Prodrome. 
 
 205. The number of these membranes is considerable, but 
 various; at this day we know about one hundred pairs. Like 
 all the serous membranes, they form membranous cavities 
 without openings; but with reference to their form, they are 
 divided into two kinds. The first are rounded vesicles hold- 
 ing on one side to the tendon, and on the other to the part on 
 which they slide: these are called vesicular. The others are 
 vaginal, surround the tendon circularly, and another part line 
 the canala in which it is contained, these two isolated parts 
 joining at their extremities so as to be separated by a space 
 that constitutes the cavity of the membrane. Among these 
 latter there are some, which are simple at one end, presenting 
 digitations at the other which answer to a similar number of 
 tendinous parts or different tendons, these latter, at first united, 
 afterwards separate from each other: this is seen in the wrist 
 under the annular ligaments. 
 
 206. The cellular tissue, loose and membraniform, which 
 is found between those muscles that produce the great and 
 continued movements, as under the latissimus dorsi,the rectus 
 anticus of the thigh, the muscles of the calf, &c., constitute, 
 in some sort, the rudiments of the membranes in question. 
 Synovial membranes are found round the tendons in those 
 places where the latter rub against the bones, slide along their 
 surfaces, or on other parts, or where they are reflected and 
 change their direction: these membranes sometimes exist be- 
 tween two tendons that move on each other. The glutaeus 
 
 * Ch. M. Koch. De bursts tendin. muc. Lips. 1789. 
 
 f F. E. Gerlach. De bursts tendinum mucosis in capite et collo reperiundis. 
 cum tabul. centis. Viteberg, 1793. 
 
 $ Icones et descript. bursar mucosar. curporis hum. Ed. T. Ch. Rosenmul- 
 Icr. Lipsisc, 1799. 
 
164 GENERAL ANATOMY. 
 
 maximus, at the spot where it slides on the trochanter, the 
 ohliquus major of the eye at the place where it is reflected in 
 its pulley, the lateral peroneals where they alter their course 
 to reach the sole of the foot, &c. are all furnished with syno- 
 vial membranes. Generally these membranes are connected 
 with bones or fibrous rings. They are very common about 
 the articulations, because, it is there especially that the tendons 
 are situated. This is seen in the wrist, the knee, &c. We 
 there find the two kinds of which we have spoken. Some of 
 these capsules are confounded with the sub-cutaneous or arti- 
 cular synovial bursae : that of the triceps for instance, is not 
 always isolated, and frequently appears like a continuation of 
 the synovial capsule of the knee. 
 
 207. The adhering face of these membranes, besides be- 
 ing attached to the tendon and the part on which it rubs, is 
 connected, in the space between both the cellular and fatty 
 tissues; it is often attached to fibrous tissue, as for instance, to 
 tendinous or fibro-cartilaginous sheaths, as in places where 
 the tendons slide upon bones, and in which place the peri- 
 osteum is like cartilage. Generally their interior presents a 
 simple cavity, sometimes a compound one, traversed by par- 
 titions, a kind of fibrous prolongations. Fimbriated prolonga- 
 tions are found in some, in that situated behind the calcaneum 
 for instance, we also find there small fatty or cellular masses, 
 but in those only that are formed like vesicles; those that are 
 vaginal contain none. These prolongations have been assimi- 
 lated to excretory ducts. Rosenmuller describes follicles in 
 these membranes I have never seen any there. They con- 
 tain villosities which pour out synovia. 
 
 208. The synovial membranes of the tendons are whitish, 
 semi-transparent, thin and soft, those that are vaginiform par- 
 ticularly, the latter having also external ligamentous sheaths. 
 The vesicular bursar are thicker, and present in some places a 
 fibrous appearance. The texture of these membranes is the 
 same as that of the others of the same genus; their tissue 
 greatly resembles the cellular tissue. The fibres, the fringes 
 and adipose masses, common to all the serous system, are also 
 found here. Serous vessels which become visible in inflam- 
 
OF THE SYNOVIAL MEMBRANES OF THE TENDONS. 1G5 
 
 mation and some blood vessels particularly apparent in the 
 fringes, enter into the composition of these membranes whose 
 lymphatics and nerves are entirely unknown. The liquid 
 they contain is viscid, more abundant than in the sub-cutane- 
 ous mucous bursae, yellowish and sometimes reddish; it is 
 oleiform, partly coagulable, and contains albumen and mu- 
 cus: it is more viscid in the mucous bursas which are the most 
 extensive. Mr. Koch has found some difference to exist in 
 this liquid, as examined in different animals, as in the ox, the 
 horse and the hog. 
 
 209. The properties of the tendinous capsules have nothing 
 particular. Their functions are to secrete and contain a mu- 
 cilaginous liquid, which facilitate the sliding by diminishing 
 the loss of motion which results from friction. 
 
 But little is known respecting the development of these 
 membranes. According to some, they are greatest in number 
 in young subjects, and by increasing in size and meeting each 
 other, they become partly confounded in old age. M. Seiler, 
 on the contrary, asserts that they diminish in extent in old 
 persons, and partly disappear. 
 
 210. They undergo some changes.* Dropsy is an affec- 
 tion not very rare in them, those which are in the neighbour- 
 hood of the skin are particularly liable to it; this may occasion 
 the disease to be confounded with hygroma. The name of 
 ganglion is given to the little circumscribed tumours resulting 
 from it, and which are often cysts also. These tumours are 
 particularly met with in the hamstrings, wrist, foot, &c.; they 
 contain a serous, albuminous, yellowish or reddish liquid, 
 similar in colour and consistence to 1 currant jelly. The ab- 
 sorption of this liquid is effected very slowly: it is accelerated 
 by crushing the tumours that contain it, as this disperses it in 
 the cellular tissue. These tumours are occasionally found much 
 larger; voluminous collections of purulent serum that have 
 been observed under the great muscles of the backj under the 
 deltoid, &c. and which have been confounded with the com- 
 
 * Monro, op. cit. Koch. De morbis bursarum tcndinum mucosaram* 
 Lips. 1790. 
 
166 GENEKAL ANATOMY. 
 
 mon abscess of the cellular tissue, are seated in membranes of 
 this kind or in those analogous to them. 
 
 Inflammation of the membranes of which we are treating is 
 a serious matter; it may be observed in one of the varieties of 
 paronychia. The results are adhesions or an abscess which 
 opens externally, and in either case the power of motion is 
 destroyed. When the adhesion is filamentous it is sometimes 
 finally removed. Chronic inflammation produces nearly simi- 
 lar results: it may also induce suppuration. 
 
 Solid cartilaginous bodies have been found in the interior 
 of these membranes by Munro, and since by many others. 
 We frequently find in them, a great number of small bodies 
 resembling apple or pear seeds in size and shape, that have 
 been considered as animated and for which the name of ace- 
 phalo cystis planet, has been proposed. They have been 
 most often found under the anterior ligament of the carpus, 
 and sometimes also in other membranes of the tendons, as in 
 those of the great gluteus, of the long flexor of the thumb, &c. 
 An incision gives them issue, but the general result is a very 
 serious inflammation and at all events an intimate adhesion, 
 which, in the wrist, for instance, confounds all the flexors in 
 one single bundle, and renders the fingers motionless. The 
 inflammation of the synovial tendinous membranes generally, 
 merits the attention of pathologists. It is the same with the 
 greater part of their morbid changes, which have often, under 
 the name of white swellings, been confounded with diseases 
 of the articulations, in whose vicinity they are situated. 
 
 ARTICLE III. 
 OP THE ARTICULAR SYNOVIAL CAPSULES. 
 
 211. Under this name, capsulx synovialeswc designated, 
 Ihe serous membranes of the diathrodial articulations. Most 
 of them belong to the bones, some to cartilages, as is the case 
 with the larynx. These membranes, like the preceding ones, 
 
OF THE ARTICULAR SYNOVIAL CAPSULE. 1G/ 
 
 are humected by a liquid internally, and impart a similar facility 
 of sliding to the parts they invest. 
 
 For a long time they were confounded with the capsular 
 ligaments of the joints. Nesbit, Bono, and W. Hunter had al- 
 ready observed that they formed a membrane distinct from 
 the articular ligaments and cartilages. Monro had remarked 
 their analogy to the other synovial and serous membranes; 
 Bichat has fixed our attention more particularly upon these 
 membranes, and has given a more complete general descrip- 
 tion of them. Monro and Mascagni have figured them. 
 
 212. The number of these membranes is very great, being 
 about equal to that of the articulations. This number is not 
 quite equal to that of the latter, because, on the one hand, some 
 of these membranes are common to several articulations, as in 
 the carpus, for instance, and on the other, some of the articu- 
 lations contain several membranes. They are found, how- 
 ever, in the articulations only. 
 
 213. The following varieties are observed in the configura- 
 tion of these membranes: 1st, some resemble simple, rounded 
 sacs, like the vesicular membranes of the tendons: this is seen 
 in the articulations of the phalanges with each other and with 
 the metatarsus and metacarpus: here is nothing at all complex, 
 and a small round ampulla is all that is attained by insuffla- 
 tion. 2d, in some articulations, the cavity of the membrane 
 seems to be traversed by a ligament or tendon about which 
 this is reflected, forming for it a sheath, continuous at its two 
 extremities with the common envelope, that the synovial 
 membrane furnishes to the articulations; this synovial mem- 
 brane is then vaginiform: this disposition is found in thecoxo- 
 femoral, scapulo-humeral articulations, &c. 3d, a greater de- 
 gree of complication is observed in some other articulations; in 
 that of the knee, for instance, we perceive a common enve- 
 lope, sheaths for the tendon of the popliteal muscle and the 
 adipose ligament, and folds moreover invest the semi-lunar 
 and crucial ligaments, which raise up the membrane and project 
 into the articulation. We might then establish, nearly the fol- 
 lowing order in the complication of the synovial membranes: 
 
 simple ampulla; an ampulla raised up by fatty flakes; this last 
 23 
 
16S GENERAL ANATOMY. 
 
 disposition joined to the presence of sheaths; lastly, besides this 
 latter, folds formed by parts which extend into the articulation, 
 and that are covered by the membrane. All these forms, which 
 are so various, are to be referred finally to the vesicular form. 
 214. The external surface of the synovial membranes is 
 more or less intimately connected with the neighbouring 
 parts. They all adhere closely to the articulating surfaces of 
 the bones, or rather to the cartilages which invest them, by 
 the two extremities of the kind of sac they represent. Their 
 connexion with these cartilages is so close as to occasion a 
 belief that the latter is naked: Nesbit, Bonn and W. Hunter, 
 however, long ago announced the existence of a prolongation 
 of the synovial membranes, upon the articulating surfaces of 
 the bones. It is to Bichat in particular, that we are indebted 
 for having, incontestably, established this truth. Some au- 
 thors, however, such as Gordon and M. Magendie, still raise 
 doubts on the subject. Many facts demonstrate the presence 
 of the synovial membranes on the cartilages. When these 
 membranes are inflamed, their redness, which in time becomes 
 apparent, extend around the circumference of the cartilage, 
 and becomes less and less sensible as it advances towards its 
 centre, the membrane becoming more and more identified 
 with the cartilage; the centre itself is finally penetrated with 
 vessels, but the cartilage is coloured only at its surface, pre- 
 serving in its thickness the whiteness peculiar to it. The 
 bridles which are sometimes formed in the synovial mem- 
 branes arise, indifferently, from all parts of their extent, and 
 it is observed that when they adhere to the cartilage, their 
 bases are less closely united to it, and that in this place, the 
 membrane becomes apparent as it naturally is about the arti- 
 culating surfaces: in this manner, the synovial membrane 
 becomes apparent even on the centre of the cartilage. The 
 fungous degeneration peculiar to the synovial membrane is 
 also to be found on the cartilage. Finally direct inspection 
 demonstrates the continuity of this membrane. By obliquely 
 raising a slice of cartilage, and afterwards bending it back so 
 as to break it at its base, it still holds by the synovial mem- 
 brane which covers it equally with the rest of the cartilage. 
 
OF THE ARTICULAR SYNOVIAL CAPSULE. 169 
 
 When a bone is sawed, break the cartilage at its extremity, 
 and the connexion is still kept up between the two halves by 
 the synovial membrane which extends from the one to the 
 other. 
 
 Throughout the remainder of their extent, i. e. on the edge 
 of the articulation, the synovial membranes are attached to the 
 articulary ligaments, in an equally close way as is seen in the 
 scapulo-humeral articulation : the adhesion is particularly in- 
 timate in the middle and becomes looser towards the extremi- 
 ties. In the intervals between the ligaments, these membranes 
 correspond to the fatty and cellular tissues: these tissues form 
 distinct pellets there as well as near the place where the sy- 
 novial membrane leaves the ligaments to be reflected on the 
 bones. 
 
 The internal surface is smooth, polished, contiguous to 
 itself, lubricated by the synovia, and furnished with villosities 
 and fimbriated prolongations. 
 
 215. The synovial membranes are thin, soft, semi-trans- 
 parent, whitish, extensible to a certain degree, although less 
 so than the splanchnic serous membrane, and retractile, a fact 
 demonstrated by their dropsy and their return to their original 
 dimensions after the evacuation of the accumulated fluid. Their 
 rupture in relaxations depends less on their want of extensi- 
 bility, than on their close connections and the small extent of 
 their folds. 
 
 216. These membranes are provided with fatty pellets 
 placed on their exterior or even in their interior, and impro- 
 perly called the synovial glands of Havers. These pellets, 
 perceived by Vesalius and Etienne, described by Cowper and 
 particularly by Cl. Havers,* until the time of Monro, were 
 regarded as the secreting organs of the synovia, t Their size 
 varies according to the quantity of fat they contain : they al- 
 ways contain more or less of this fluid, and are almost entire- 
 ly formed of adipose tissue. The fringes exist on the inte- 
 
 * De ossibus, sernio iv. chap. I. 
 
 f See Pitschel. De axungid articular. Lips. 1740. Hanse. De unguine 
 articulari, efusque vitiis. Lips. 1774. 
 
170 GENERAL ANATOMY. 
 
 rior of the membrane, at the spots where the pellets are placed 
 without. The points in which these different objects are 
 found, are those where the membrane is most vascular. The 
 fringes contain in their thickness, cellular tissue, fat and blood 
 vessels: the other parts of the synovial membranes only re- 
 ceive serous vessels. Lymphatics are apparent in some of 
 these membranes only; it is useless again to revert to the 
 theory of Mascagni which this author applies to all the trans- 
 parent membranes. The nerves of the synovial capsules are 
 not known. 
 
 217. The liquid secreted by these membranes or the sy- 
 novia, synovia, so named by Paracelsus on account of its im- 
 perfect resemblance to the white of egg, is the result of a per- 
 spiratory secretion, although various other opinions have been 
 entertained about the mechanism of its formation. This fluid 
 is not, as it was for a long time thought to be, the product of 
 a mixture of serum and fat; the marrow of the bones does 
 not transude to form it as we have seen; the synovia, in its 
 natural state does not even contain any oil. The supposed 
 glands of Havers can not, from what we have said, fulfil the 
 functions ascribed to them, and the fringes that surmount 
 them, are not, as he thought, excretory ducts: it is but very 
 lately, however, that this glandular structure has been sup- 
 posed to have been found; in fact, nothing glandular can be 
 observed in the synovial masses, no granulations nor excre- 
 tory ducts.* Even the fat they contain is not essential to 
 their structure, and besides, as there is no oil in the synovia, 
 it is not from the transudation of the first of these fluids, when 
 it exists, that the second owes its origin. Rosenmuller pre- 
 tends that there are secretory follicles in these adipose pellets: 
 I have never seen these follicles, nor do I know that any one 
 since has proved their existence. The secretion of the syno- 
 via then, is neither glandular, follicular, nor a simple result of 
 transudation, but truly perspiratory; it has its seat throughout 
 the whole extent of the synovial membranes, that portion of 
 them, particularly, which surmounts the fringes, and which 
 
 * See Hey liters, Dissertatio physiol. ana/, de fabrica arlicul, 1803. 
 
OF THE ARTICULAR SYNOVIAL CAPSULE. 171 
 
 is owing to the great number of vessels it contains. The sy- 
 novia is partly taken up by absorption, and its quantity in a 
 normal state, being always about the same, supposes an equi- 
 librium between absorption and secretion. 
 
 This liquid known to the Greeks who called it JU|Q tw> apflpw, 
 and long known as axunguia, is viscid and has a saltish taste; 
 its specific gravity is 105, that of water being 100. Its che- 
 mical composition has been examined in animals as well as 
 man, but more particularly in the ox by Margueron, Four- 
 croy, T. Davy, Hildebrandt, M. Orfila and several others. 
 There are found in it water, albumen, mucus or incoagulable 
 matter, considered by some as mucilaginous gelatine, a thready 
 matter, which some think is fibrine and others albumen in a 
 particular state, soda, muriate of soda, phosphate of lime, and 
 an animal matter said to be uric acid. The use of the synovia 
 is to diminish friction and to facilitate thereby the sliding of 
 the parts. 
 
 218. The synovial capsules of the articulations present 
 some pathological alterations.* They are repaired when di- 
 vided; but their mode of reunion is not well understood; 
 there are no precise facts in the history of wounds of the arti- 
 culations, and of luxations, relative to it. New synovial mem- 
 branes are sometimes formed as is observed in false joints, after 
 unreduced luxations; in this case, described by Dr. Thompson 
 and observed by myself, the remains of the old capsule and 
 the cellular tissue united, form a new membrane very similar 
 to the first. In false articulations, which succeed to fractures 
 that have not been consolidated, there is also found a closed 
 membrane, smooth within, containing a viscid liquid more or 
 less analogous to the synovia. 
 
 Dropsy of the joints constitutes hydrarthrosis; in this affec- 
 tion, the synovia undergoes various changes. 
 
 219. Inflammation produces the same alterations of tissue 
 and functions in these, as in the serous membranes generally. 
 
 * See Reimarus, de tumore ligament, etc. Leyd. 1557. Wynpersse, de 
 ancylosi. Leyd. 1783. Ejusd.de ancylpathol Leyd. 1783. Brodie, Traite 
 des maladies des articulations. Paris, 1819. 
 
172 GENERAL ANATOMY. 
 
 They become a little thickened, redden to a greater or less ex- 
 tent, are covered with albuminous granules, and sometimes 
 finally form adhesions. The inflammation may terminate by 
 resolution, and it then leaves a stiffness, occasioned by the 
 thickening of the surrounding parts : the membrane itself, 
 also, generally remains thickened. Flowing of pure synovia, 
 lactescent serum, or serum containing albuminous floculi, or 
 even true pus, may also result from the inflammation. The 
 adhesions it finally forms, constitute one of the species of an- 
 chylosis. There are, as is well known, several kinds of this 
 disease: they all depend, however, upon the changes of the 
 synovial membrane, and sometimes of the parts exterior to it. 
 Thus in false anchylosis, there appears to be a thickening, an 
 induration of all the parts surrounding the articulations. Ano- 
 ther species, to which, if worthy of preserving, the epithet 
 false, might be applied, is characterized by adhesions of the 
 synovial membrane. The articulation then becomes an am- 
 phiarthrosis, bridles or synovial lamina uniting the diarthro- 
 dial surfaces: these bridles are so numerous that they repre- 
 sent a sort of cellulosity; according to their number, length 
 and extensibility, the motions are more or less limited; a 
 thickening and induration of the soft parts, are added to this, 
 the end of all which is, that the parts never perfectly resume 
 their accustomed motion. In true anchylosis, adhesions are 
 not only established between the articulating surfaces, but these 
 surfaces become soldered together, confounded, the continuity 
 is perfect between the bones, whose compact laminae, as well 
 as whose cartilaginous laminae which separate them, finally dis- 
 appear, so that their spongy tissue is confounded; this change 
 begins in the synovial membrane, for this reason we speak of 
 it here. Ulceration is a more rare termination of inflamma- 
 tion in the synovial membranes. 
 
 220. In white swellings, among which are included various 
 changes, such as inflammation, dropsy, diseases of the carti- 
 lages, &c., is found an alteration peculiar to the synovial mem- 
 branes: it is a state in which these membranes are converted 
 into a fungous substance, from whence springs a vegetation 
 that extends to the skin, and even penetrate through it. Reima- 
 
OF THE SEROUS SPLANCHNIC MEMBRANES. 173 
 
 rus, Brambilla, and M. Brodie have described these cancerous 
 fungi. 
 
 221, Foreign bodies are formed in the articulations: they 
 are most generally seated in the knee. Their size as well as 
 their number and consistence varies, as has been already stated, 
 while speaking of the serous system in general; they are form- 
 ed outside the synovial membrane, and appear to be the result 
 of a peculiar change of the nutrition. They gradually advance 
 into the interior of the membrane, and are finally detached in 
 the way before mentioned. Their presence, which is accom- 
 panied by violent pain, when placed between the articulating 
 surfaces, produces no uneasiness, when in moveable parts, and 
 where the articulation is loose. Depressions more or less deep, 
 are sometimes finally made by their pressure on the cartilages, 
 and as these depressions correspond in form to that of the bo- 
 dies lodged there, it has been said, that the latter were pieces 
 of cartilage separated by external violence; but to prevent the 
 admission of this opinion, it is sufficient to consider, that in 
 the greater number of cases in which those bodies are found, 
 the depressions do not exist, that they have no resemblance to 
 fractured surfaces, and that the bodies are much thicker than 
 the articular cartilages themselves. 
 
 ARTICLE IV. 
 
 OF THE SEROUS SPLANCHNIC MEMBRANES. 
 
 222. The serous membranes, properly so called, also styled 
 the diaphanous membranes, are those which line the splanchnic 
 cavities, and which furnish tunicks more or less perfect, to the 
 viscera situated therein. 
 
 223. These, like all other serous membranes, were for a 
 long time confounded, both in their healthy and diseased con- 
 ditions, with the organs they envelop, and the parts they in- 
 vest. With respect to the first, however, each of these mem- 
 branes had been successively and exactly described, independ- 
 ently of the parts they cover; some anatomists, Monro for in- 
 
174 GENERAL ANATOMY. 
 
 stance, had even indicated the analogy that exists between 
 them. As regards their pathology, Sauvages and M. Pinel 
 had already established an order of inflammation for that of the 
 diaphanous membranes, but one comprehending the inflamma- 
 tions of the stomach, of the intestine, bladder, and epiploon, as 
 so many genera. Various pathologico-anatomical observations, 
 those of T. G. Walter on the peritoneum, in particular, had 
 shown that this membrane, like all other serous membranes, 
 could be affected throughout its whole extent, and independ- 
 ently of the subjacent parts; finally, Dr. Carmichael Smith had 
 noted with exactness, the identity of the inflammation of all 
 the diaphanous membranes, when Bichat gave his exact and 
 complete description of the serous membranes, and particu- 
 larly of the arachnoid. Descriptions of some of these mem- 
 branes have been given since;* but little, however, has been 
 added to what our celebrated anatomist has said; more has 
 been added to ther pathological history. 
 
 224. The serous membranes of which we are now speak- 
 ing, are situated in the cavities of the trunk, which they line; 
 they there invest the most important organs, those that are the 
 most essential to life. These membranes are distinct and se- 
 parate from each other; their number is but small; viz. 1st, 
 the peritoneum in the abdomen, where it invests more or less 
 perfectly the greater part of the organs of digestion, that are 
 contained in this cavity, and rather less the genital and urinary 
 organs; 2d and 3d, the two pleuras, and 4th, the pericardium 
 in the chest, where each one of these membranes is restrained 
 to a single organ, and to the parietes of its cavity; 5th, the 
 arachnoid in the cranium, and in the spinal canal; 6th and 7th, 
 in man only, the tunica vaginalis. 
 
 The extent of these membranes, collectively, is very consi- 
 derable, and greatly surpasses that of the skin. The perito- 
 neum is the greatest of these membranes, its extent being 
 equal, at least, to that of all the others together. 
 
 225. The general description of the serous membranes, 
 
 * See JLangenbeck. Commentarium, de structure, peritonceci. ect. cum tabu- 
 Its. Getting, 1817. L. Rolando. Osservazioni sul peritonea et sulla pleura 
 in mem. della real dead, de/le srienze. Tom. xxiv, Turin, 1820, 
 
OP THE SEROUS SPLANCHNIC MEMBRANES. 175 
 
 has already in a great measure explained the species of which 
 we are now speaking, and which may be considered as the 
 type of the genus. Their form is the same as that of all the 
 serous membranes, that of a bladder without an opening, and 
 with contiguous parietes. On the one hand, it lines the inter- 
 nal surface of the parietes of the cavity in which they are con- 
 tained, and on the other, it furnishes tunicks or external en- 
 velopes to the organs. The pleura, the pericardium, and tu- 
 nica vaginalis have a tolerably simple conformation, their pa- 
 rietal and visceral portions, continuing around the point where 
 the organ they invest is attached by vascular prolongations, 
 to the parietes of the cavity that contains it. As to the arach- 
 noid and peritoneum, their disposition is a little more com- 
 plex, without, however, ceasing to be essentially the same. 
 With respect to the first, the complication is owing to the 
 great number of vessels and nerves that terminate in, or de- 
 part from the brain. Now on each of these parts, the arach- 
 noid forms a sheath, which continues to one of its extremities 
 with the visceral lamina of the membrane, and to the other, 
 with its parietal lamina, an arrangement, previously pointed out 
 and figured by Bonn, to which Bichat has particularly drawn 
 our attention, and from which it results, on the one hand, that 
 the membranous cavity is not open, and that the parts of the 
 membranes are continuous to one another. As to the perito- 
 neum, its complexity depends upon the great number of parts 
 to which it furnishes coverings, and upon the various disposi- 
 tion of these parts, of which some are very near the posterior 
 wall of the abdomen, whence they receive their vessels, and 
 are simply covered with the peritoneum; others again are re- 
 moved from it, sometimes greatly so, and are suspended to 
 membranous bridles which contain the vessels in their thick- 
 ness. Its complexity depends also upon vascular prolonga- 
 tions, projecting beyond the viscera, and to which the serous 
 membrane furnishes epiploical or floating envelopes. This 
 membrane is peculiar also in being the only one that has an 
 opening communicating externally through the fimbriated bo- 
 dy, and fallopian tubes. More extensive details on the con- 
 formation of the splanchnic serous membranes, belong to the 
 24 
 
176 i-ENEKAL ANATOMY. 
 
 special anatomy of these membranes, and particularly to that 
 of the peritoneum and arachnoid. 
 
 226. Of the two surfaces of these membranes, one is gene- 
 rally free, in a healthy state, and the other adherent. The 
 free surface is shining, moist, and appears polished ; it is, how- 
 ever, covered with small villosities which become visible on 
 looking at it under water, and which the inflammatory irrita- 
 tion renders very apparent. It is to the serous membranes 
 which envelop and line them, that the organs and parietes of 
 the splanchnic cavities owe their shining aspect; wherever 
 they are without it, they have not the same appearance. This 
 free surface, every where contiguous to itself, as well as the 
 serosity.that humects it, creates a distinctness, a true isolation 
 between parts very nearly approximated; they also singular- 
 ly facilitate the motions of these parts. 
 
 227. The other surface of the serous membranes is almost 
 universally adherent, either to the viscera or the walls of the 
 cavities; there are only some prints of the visceral lamina of 
 the arachnoid, which are free on the two surfaces, every where 
 else the external surface of the serous membranes is adherent. 
 This adhesion is on one side with the parietes of the cavities, 
 and on the other, with the surface of the viscera. The degree 
 or solidity of this adhesion generally varies. In general, 
 wherever the serous membranes are connected with a liga- 
 mentous tissue, as with the dura mater, the pericardium, the 
 aponeuroses of the abdominal parietes, the tunica albuginea of 
 the testis, &c. there this adhesion is very intimate; it is also 
 very great with the muscular and other parts, as the heart, 
 lungs, stomach, intestines, &c. ; it is much less so, in other 
 places, as where the membrane passes from an organ to the 
 walls of a cavity, and vice versa; where it forms bridles, or 
 floating prolongations that contain vessels; in the places where 
 the sub-serous cellular tissue contains fat,and, generally, where- 
 ever it is loose. 
 
 228. These differences are of sufficient importance to de- 
 mand further attention; the consequence is, that when, for 
 Example, the uterus, the bladder, the stomach and the intes- 
 tines augment in volume, the peritoneal bridles and ambiant 
 
OF THE SEBOUS SPLANCHNIC MEMBRANES. 177 
 
 folds open, spread out, and are applied to the organs, and then 
 when the latter recede to their original condition, the mem- 
 brane becomes foreign to them; this is owing to the laxity of 
 the sub-serous cellular tissue, near the adhering edge of these 
 folds. When a hernia is produced in the groin and increases 
 in size, it is chiefly by the displacement, the sliding of the 
 serous membrane, assisted by the laxity of the adhesions, that 
 the sac increases; when, on the contrary, an umbilical hernia 
 augments in volume, it is by thinning and distention, that the 
 sac increases, the adhesion of the peritoneum about the umbi- 
 licus being intimate. Bichat has, perhaps, exaggerated a little 
 the influence which the laxity of the adhesions of the serous 
 membranes, may have in limiting their diseases and those of 
 the subjacent parts. 
 
 229. The physical properties of these membranes are. 
 those of the serous system in general already described: they 
 are thin, but this tenuity is not the same in all, neither is it so 
 in all parts of the same membrane, nor in different individuals. 
 Soft, semi-transparent, &c.; their extensibility is strongly 
 marked, more so than that of the synovial membranes; their 
 strength tolerably great, and much greater than that of the 
 cellular tissue; they are slightly elastic. When these mem- 
 branes are distended beyond a certain degree, their texture 
 becomes loose; this looseness is on the free surface; the rest 
 of the thickness of the membranes, resists the laceration more 
 strongly, or yields more to the distention. 
 
 230. They all consist of one lamina, which is so much 
 the more dense and close, if examined on the free surface, and 
 whose texture is more lax on the opposite side where it be- 
 comes flaky and is confounded with the common cellular tissue. 
 Until the period when Douglass gave an exact description of 
 the peritoneum, this membrane as well as those of the same 
 species was considered as bifoliate, and containing the viscera 
 in the space between their separated layers: it was an error 
 which he refuted, and that Vacca and others have vainly tried 
 to revive. The pretended external leaflet is nothing more 
 than the sub-serous cellular tissue, so well described by Doug- 
 lass. They consist essentially of one layer of extremely close 
 
178 GENERAL ANATOMY. 
 
 and condensed cellular tissue, more and more distinct from 
 the cellular tissue, from the adhering surface where it insensi- 
 hly continues with it, to the free surface where it greatly dif- 
 fers; fibres or little interlaced fasciculi are not so manifest in 
 it as in the synovial membranes. The floating appendages of 
 these membranes contain, also, free cellular tissue, and often 
 fatty tissue ; they are much more vascular than the other serous 
 or synovial membranes. They contain an immense quantity 
 of white or serous vessels which become visible by injection, 
 congestion, or inflammation and some very delicate red ves- 
 sels, which belong to their external surface, and particularly 
 to the sub-serous cellular tissue, as may be proved by detach- 
 ing the membrane, which is found to be white in those places, 
 where one would have supposed there was a number of red 
 vessels that were in fact only seen through it. The red ves- 
 sels are particularly abundant in the loose or floating folds. 
 Nerves have been traced to these membranes, but not into 
 their substance. 
 
 231. These membranes, when dried, become transparent, 
 elastic and tolerably firm, assuming a light yellowish colour; 
 by immersion in water they resume their original properties. 
 Maceration first renders them soft, opaque and thick, then 
 pulpy, and ends, but after a very long time, by dissolving 
 them. In bodies beginning to be decomposed, these mem- 
 branes impregnate themselves with liquids on the one hand, 
 and permit them to transude on the other, hence their diver- 
 sity of colour. Fire and boiling water render them horny. 
 Continued ebullition converts them into gelatine and a little 
 albumen. These different characters approximate them to 
 the cellular and ligamentary tissues. 
 
 The force of formation is less developed in them, than in 
 the free cellular tissue. Irritation produces no sensible motions 
 in them, but it changes their secretion and texture; it inflames 
 them. They are sensible in this state only, in which they 
 usually become the seat of violent pain. 
 
 232. In a state of life and health they are humected on 
 their contiguous surface by serum they are continually depo- 
 siting and absorbing. This secretion had been attributed to 
 
OF THE SEROUS SPLANCHNIC MEMBRANES. 179 
 
 certain glands supposed to be lodged in their tissue. Ruysch 
 has proved that these pretended glands do not exist. Hunter 
 thought that this secretion was produced by a true transuda- 
 tion, analogous to the cadaverous transudation through the 
 areolae, interstices or an organic porosities of the tissue of the 
 vessels. Although the true way and organic mode by which 
 the perspiratory and other secretions are performed, are not 
 well known, we may at least affirm that they differ from tran- 
 sudation, which takes place only in the dead body. The sero- 
 sity in the healthy state is so small in quantity, as to be 
 scarcely perceptible, and hardly capable of being collected. 
 Hewson collected, from animals suddenly killed, a small quan- 
 tity of the liquid that humects the serous membranes, and he 
 saw by exposing it to the air and leaving it at rest, that it 
 coagulated like the coagulable lymph of the blood. He was 
 not able to collect the serosity of the cellular tissue. Bostock 
 has found in the healthy serosity of the splanchnic cavities, 
 water, albumen in less proportion than in serum, incoagula- 
 ble matter and salts. Schwilgue found in it, albumen, an ex- 
 tractive matter, and a fatty matter. From the examination that 
 1 have made of the serosity of the splanchnic cavities, it seems 
 to me, that the incoagulable matter is gelatiniform mucus, 
 similar to that found in the coagulated albumen of the serum 
 of the blood. The coagulability of the healthy serosity, ob- 
 served before Hewson by Lower, Lancisi, and Kaau, has 
 been, on the contrary, denied by Sarcone,Cotunnio and Gero- 
 mini;* I believe this coagulability always exists in the healthy 
 state. 
 
 233. Of all the serous membranes, those of which we now 
 speak, are those whose functions and morbid actions are the 
 most closely connected with the other organic phenomena, 
 presenting, however, some varieties; thus the membrane of 
 the testicle, and that of the abdomen, differ greatly in this 
 respect. 
 
 234. The greater part of what has been said respecting 
 the morbid changes of the whole serous system, may be ap- 
 
 * tfaggio sullagenesi, e cura ddl" idrope. Cremona, 1816. 
 
180 GENERAL ANATOMY. 
 
 plied to these. They are subject, more than the other, to some 
 primitive vices of conformation, as unnatural openings, ob- 
 served in some cases of monstrosity, of which they all may 
 present examples, as well as the prolongations or appendages 
 which envelop congenital hernias and other displacements. 
 
 235. Accidental hernias are also accompanied by an altera- 
 tion in the form of the splanchnic serous membranes; displaced 
 parts are almost universally enveloped by a hernia! sac: this 
 sac is formed by the serous membrane which lines their pa- 
 rietes, and which the viscera, in being displaced, push before 
 them. 
 
 236. Dropsy, inflammation and its effects, false membranes, 
 adhesions, accidental productions, either analogous, or morbid, 
 are more common in the splanchnic serous membranes, than 
 in the other species, and still more common among some of 
 their own number than in others. 
 
 237. Although the splanchnic serous membranes, form a 
 tolerably natural group, they still present differences which 
 belong to special anatomy; the arachnoid besides, differs much 
 from the others. It has the same conformation as the others, 
 but its consistence is soft, its tenuity extreme, and its texture 
 it is impossible to determine; it seems homogeneous; no ves- 
 sels are to be found in it, not even in a diseased state. The 
 greater part of the morbid phenomena attributed to it, takes 
 place in the subjacent tissue of the pia-mater; it seems, in fact, 
 to form a genus by itself. 
 
OF THE TEGUMENT ARY MEMBRANES. 1S1 
 
 CHAPTER III. 
 
 OP THE TEGUMENTARY MEMBRANES. 
 
 238. These membranes are those which, internally as well 
 as externally, clothe the parts that are exposed to contact with 
 foreign substances. They are also called compound villous, 
 or folliculous membranes, on account of the numerous parts 
 which enter into their texture, and of the follicles which they 
 contain in particular. They constitute, next to the cellular 
 tissue, of which they are a modification, more or less com- 
 pound, the most universally extended tissue or organ in the 
 animal kingdom; they are the first parts that are distinct and 
 figured in the embryo; it is on them and by them that all the 
 rest, of the body is formed; in health during life, they are the 
 organs of the most essential functions; and it is in them and 
 by them that absorption and extensive secretion takes place; 
 it is upon them that all foreign substances produce impres- 
 sions ; they are often changed by disease; it is on them, in 
 fine, that most therapeutic agents are applied: their study then 
 is of the highest importance to the physician. 
 
 239. Galen* had already remarked, that besides the ex- 
 ternal skin, which is the common tegument of all the parts, 
 there is a thin membranous skin which clothes the internal 
 parts; several anatomistst had already indicated the continua- 
 tion of the skin into some of the natural cavities, andj the 
 analogy of the mucous membrane with the epidermis; Bonn 
 had already described in detail, the continuation of the skin 
 with the internal membrane, into all the openings and cavities; 
 
 * Of the therapeutic method, I. xiv. chap. 2. 
 
 f Casserius, Pentaestheseion, hoc est, de quinque sensibus, liber. 
 
 + Glisson. De Guld,ventricub etintestinis. 
 
 D* continuationibui, membranarum. 
 
182 GENERAL ANATOMY. 
 
 zootomists and naturalists had also observed it, as well as the 
 analogy subsisting between these two parts of the same mem- 
 brane, in the interval of which all the rest of the body is 
 placed. Bichat has particularly insisted upon this continuity. 
 M. J. B. Wilbrand* has recently given an exposition in detail 
 of the cutaneous or tegumentary system in all its divisions. 
 M. Hebreardt has described the transformation of the skin 
 into mucous membrane and vice versa. 
 
 240. The tegumentary membranes, throughout their whole 
 extent, have common characters, of which it is necessary to 
 speak first, but from their difference of situation, texture and 
 functions, they are divided into two parts, which must, subse- 
 quently, be separately described: these parts are, the mucous 
 membrane and the skin. 
 
 SECTION I. 
 
 OF THE TEGUMENTARY MEMBRANES IN GENERAL. 
 
 241. The teguments, however extensive and numerous 
 they may seem, form one single and same membrane, every 
 where continuous to itself from the external skin, to the bot- 
 tom of the last ramifications of the excretory duct of the most 
 deeply seated gland : this membrane consequently has im mense 
 breadth. Its situation is everywhere external or superficial, 
 inasmuch as it is situated on the surfaces of the body whose 
 limits it forms, and as it is every where in contact with substances 
 foreign to the organization; but one portion only is visible ex- 
 ternally, and envelopes the whole body, while the other part 
 is hidden, and lines the alimentary canal, which traverses the 
 trunk through its whole length, from the mouth to the anus. 
 We may hence easily conceive the figure of the tegumentary 
 membrane, to be that of an envelope, and of a canal which 
 
 * Das, huutsystem in alien seinen verzwergungen, anatomisch, physiol. unit 
 patJiol. dargestellt. Giessen, 1813. 
 
 f Mtm. sur fanalogie qui existe entre le systeme wiiqiieux ft dfrmoide,- 
 Mem. de la Soc. med. TfEmul vol. viii. p. 153. 
 
OF THE TEGUMENTARY MEMBRANES IN GENERAL. 183 
 
 traverses it, continuous with each other to the two extremities; 
 or rather as that of two canals, the one wide, the other narrow, 
 the narrow one cased, in the other, and continuous to the two 
 ends, and in the space between which the remainder of the 
 body is lodged. If we wished to employ a trivial comparison, 
 the one which is best fitted to represent this disposition is that 
 of a muff, having in fact two surfaces separated by a layer of 
 intermediate substance, more or less thick. 
 
 242. Besides the skin and the mucous membrane of the 
 alimentary canal, continuous with each other to the two orifices 
 of this canal, every where continuous with themselves, and 
 which constitute the two principal parts of the tegumentary 
 membrane, this membrane has a great number of dependencies 
 or prolongations more or less extended and ramifiecj in the 
 thickness of the body: such are, 1st, the genital and urinary 
 membranes, which are prolonged into all the cavities of the 
 organs of generation, and the urinary depuration; 2d, the pul- 
 monary membrane which lines all the divisions of the bron- 
 chiae : 3d, the membranes which line the excretory ducts of the 
 glands, whether they terminate in the mucous membrane, or 
 like those of the mammae, in the skin ; 4th, those of the nasal 
 cavities, of their sinuses, and posterior nasal fossae, of the audi- 
 tory canals, of the tympanum, of the mastoid sinus, and of the 
 surface of the eye. 
 
 Among these prolongations, all mucous, except that of the 
 external auditory canal, which is cutaneous, the greater por- 
 tion of them terminate in and are appendages or prolongations 
 of the mucous membrane; the external skin, on the contrary, 
 is much less complicated by appendages of this kind. 
 
 243. The tegumentary membrane presents, in its vast ex- 
 tent, differences of appearance, of texture, and of function, 
 which might induce one to doubt of its unity and continuity. 
 
 The skin and mucous membrane compared with each other, 
 at the first glance, seem to be very different; but in the animal 
 series, the difference is gradually effaced in the more simple 
 animals; it is also, generally, but slightly marked in the higher 
 animals which inhabit the water. In the human foetus, the 
 
 difference, though real, is at first but slightly defined, Even,. 
 25 
 
1S4 GENERAL ANATOMY. 
 
 in the adult we see the skin easily transformed into mucous 
 membrane, and the latter into skin. When, for example, B 
 part of the surface of the body, is for a long time substracted 
 from the action of the atmosphere, as has been seen in cases 
 of contractions, where the leg has been strongly flexed upon 
 the thigh, as is often seen in the furrows of the skin of very 
 fat children, the epidermis softens and disappears, and the skin 
 at last secretes mucus. In a prolapsus of the uretus, on the 
 contrary, we see the mucous membrane of the vagina, and in a 
 prolapsus of the anus, natural or accidental, that of the rectum, 
 thicken, dry and assume the appearance of the skin. Finally, 
 in a healthy state, in many parts, we see the skin change into 
 mucous membrane gradually and insensibly; this is the case 
 in the labia pudendi, the prepuce, anus, mammae, and nostrils; 
 it is only in the eyelids and lips that the line of demarcation 
 appears somewhat defined. There is then no real interruption, 
 but, on the contrary, there is a perfect identity and continuity 
 between the two principal parts of the tegumentary mem- 
 brane. 
 
 244. The various parts of these two principal portions of 
 the tegument, present also tolerably great differences. Those 
 which are observed between the skin of the back and that of 
 the eyelids, between those of the cranium and of the papillary 
 extremities of the fingers, for instance, are tolerably great, but 
 the} 7 are neither absolute nor definite; it is about the same in 
 the mucous membrane, and the interruptions which have been 
 supposed to be found there, are merely apparent, as will be seen 
 hereafter, (sec. ii.) The differences that are observed between 
 the various parts of the mucous membrane, although more 
 strongly marked than those which are found in the skin, are 
 not more real. The change of appearance and texture is ge- 
 nerally gradual, as is visible in the excretory ducts where the 
 membrane becomes progressively thinned and degraded, if we 
 may so express it, but in an insensible manner. If we com- 
 pare the membrane of the frontal sinuses, with that of the 
 stomach, we will certainly find great differences between 
 them, as well as between those of the tongue and of the 
 uterus; but these differences are, in a manner, connected by 
 
OF THE TEGUMENTART MEMBRANES IN GENERAL. 185 
 
 intermediate gradations. We only find some suddenly marked 
 differences, in parts closely approximated, but whose func- 
 tions are very different, as between the oesophagus and the 
 stomach, the vagina and the uterus; but even there as well as 
 every where else, they are only varieties, which easily reduce 
 themselves into a unique type of organic texture. 
 
 245. The teguments have a free and an adhering sur- 
 face. The first is turned outwards for the skin, and inwards 
 for the mucous membrane; it is the inverse with the second. 
 The adhering surface corresponds to the mass of the body 
 and to the cellular tissue generally. This tissue [139] 
 forms there a layer more or less dense, more or less thick; 
 in other places it is the ligamentous tissue, or the fibrous elas- 
 tic tissue which lines the teguments; in a considerable por- 
 tion of their extent, they are lined with muscular fibres. 
 
 246. The tegumentary membrane, besides the great ap- 
 pendages and excretery ducts of the glands of which we have 
 spoken [242], has an innumerable multitude of other depres- 
 sions, more simple and a great deal smaller, that have been 
 called follicles, loculae, lacunae, crypta, simple glands, &c. 
 These follicles,* at first observed and described in some points 
 of the teguments by various anatomists, and afterwards in 
 all the parts by Malpighi, Boerhaave, Kaau, and many 
 others, exist in all or nearly all the parts of these membranes. 
 The follicles are round, or obround, graniform, of a variable 
 size and generally very small: they are situated, in part, in 
 the thickness of the membrane, and project more or less under 
 its adhering surface. They have generally the form of a 
 little ampulla, whose mouth more or less lengthened, opens 
 on the free surface of the membrane. They are formed by 
 a reflected fold of this membrane, constituting a depression 
 or a little cul-de-sac. They constitute the pores that are per- 
 ceived on the surface of the skin, in the nose particularly, as 
 well as the granulations that line and elevate the mucous 
 
 * See M. Malpighi, Epistola de structurd glandularum, etc. in op. posthum. 
 Opusculum, anatomicum, de fabrica glandularum, continens, binas episto- 
 las. Boerhaave et F. Ruyschii, etc. in op. omn. Ruyschii. A. Kaau. Per' 
 spiratio dicta ffippocrati, ttc. Cap. xi. xii. et xiii. 
 
186 GENERAL ANATOMY. 
 
 membrane in many places; the cavity. of these follicles is ex- 
 tremely small in comparison with the thickness of its parietes. 
 They are formed by the whole membrane, whether still pre- 
 serving its thickness, or having it increased or diminished. 
 They are surrounded by an immense number of minute vas- 
 cular ramifications. The majority of these little ampulla are 
 simple, distinct, and placed more or less apart from each other; 
 but in certain parts of the skin, and of the mucus membranes 
 especially, follicles are found variously assembled and com* 
 posed. Besides these follicles of which we are speaking, the 
 tegumentary membranes, and chiefly the internal one, pre- 
 sents many depressions, whose orifice is as large as the bottom, 
 and which are called alveolar, and both the one and the other 
 present a great number of little tapering, or infundibuliform 
 depressions. The follicles differ from each other, also, in the 
 nature of the liquid they secrete and contain : those of the skin 
 are called sebaceous follicles, and those of the internal tegu- 
 ment, mucous follicles, so styled on account of the liquid they 
 furnish; those of the mucous membranes in the vicinity of the 
 skin are almost of a mixed nature, participating of both. 
 
 247. The teguments have a foliated texture; throughout 
 a great part of their extent they are evidently formed of two 
 layers, the dermis and the epidermis ; in many places, another 
 tolerably compound layer is found between the two first ; and 
 in a great number of parts, there are, besides, appendages, or 
 productions, arising from the free surface of the membrane. 
 
 248. The dermis, whatever differences it presents in the 
 two teguments and in their divisions, is always the deepest 
 part of them, the thickest, that which forms their base, and on 
 the surface of which the others are placed. It is formed of a 
 layer of fibrous cellular tissue, more or less dense, furred, and 
 leaving interstices through which pass various other parts. 
 
 249. Blood-vessels, lymphatics and nerves, more or less 
 numerous, are distributed and ramified through the thickness 
 of the dermis and on its supernces, where they form inequali- 
 ties called papillae, villosities, vascular buds, and which will 
 be more exactly defined and described, when speaking of 
 each of the two teguments. 
 
OF THE TEGUMENTARY MEMBRANES IN GENERAL. 1ST 
 
 250. The surface of the dermis is covered with a layer 
 more or less distinct, according to the part of the tegument, 
 and which is called the mucous or reticulated body; it is cel- 
 lular tissue, in a semi liquid, or imperfectly organized state, 
 in which the most minute divisions of the white vessels arise 
 or terminate; this layer, otherwise very compound, is the seat 
 of the colour, and that of the horny incrustations which cover 
 the teguments in some places. This layer is less distinct in 
 the mucous membranes than in the skin* 
 
 251. Finally, the epidermis is the last essential part of 
 the tegumentary membranes, that which forms their free sur- 
 face; it is an albuminous layer excreted on the surface of the 
 mucous body. In many parts of the mucous membranes, the 
 epidermis is not distinct and seems to be substituted by mucus. 
 Independently of this, and as regards the chemical nature of 
 the matter, there is much resemblance between the epidermis 
 and mucus. 
 
 252. Several parts of the tegumentary membranes, are 
 provided with salient appendages on their free surface: those 
 are, the nails and hairs for the skin; and the teeth, for the 
 mucous membrane. 
 
 253. By decoction, the teguments are resolved almost en- 
 tirely into gelatine. The very different colours of the tegu- 
 ments depend partly upon that of the blood and partly upon 
 a colouring matter secreted from it, in the mucous body. Their 
 very variable density, is nearly intermediate between that of 
 the cellular, ligamentous, and elastic tissues. Their elasticity 
 is tolerably well marked. They possess, also, a very great, 
 but slow extensibility and retractability, Their formative 
 power is highly developed. Although their irritability is 
 much less evident than that of the muscles, they possess a 
 large share of it. They are the essential organ of sensibi- 
 lity. 
 
 254. The organic action or function of the tegumentary 
 membrane is very important, very complex and different in 
 the different parts of that membrane. As a tegument or en- 
 velope of the mass of the body, internal as well as external, 
 it constitutes a barrier through which must pass inwardly 
 
188 GENERAL ANATOMY. 
 
 from without, all the foreign substances that enter into the 
 body to become portions of it, and from within outwardly, all 
 those which after having been parts of it, become foreign to it; 
 these substances and all others which are in contact with the 
 tegument, determine impressions on it; thus this membrane is 
 an organ of defence or protection of more or less efficacy, 
 against the action of external bodies ; it is the organ of external 
 absorptions and secretions, i. e. of those, the matter of which is 
 taken from, or deposited without ; it is the organ of all external 
 sensations, and of the feeling of want and appetite; and, finally, 
 through its appendages, it is sometimes an organ of offence or 
 aggression. But the functions of this membrane vary in the 
 different regions, according to the nature of its texture ; thus 
 the mucous membrane is better fitted for absorption and secre- 
 tion than the skin, while the latter is more adapted to receive 
 sensations and defend the body than the former. Some parts are 
 specially fitted for sensation, and even for this or that sensa- 
 tion, others for absorption, some for excretion, others for 
 generation, respiration, &c. 
 
 255. The immense extent of the tegumentary membrane, 
 the number and importance of the functions of which it is the 
 seat and instrument, render its consideration a matter of much 
 importance, both in health and disease. Between the two 
 principal parts of which it is composed, there exists the most in- 
 timate relation, which in certain respects, was perceived by the 
 most ancient observers,* who knew that the abundance of the 
 mucous secretion is generally in an inverse ratio to that of the 
 cutaneous secretion. Observation has taught us that a healthy 
 state of the skin coincides with a similar condition of the mu- 
 cous membrane, and that, for instance, those persons whose 
 skins are very white, and of a fine delicate texture, are very 
 liable to diseases of the skin and mucous membrane, and 
 particularly to discharges from these two membranes. It 
 has also taught us that every part of the skin sympathizes with 
 the whole mucous membrane, and with this or that part of it 
 especially. There also exists an equally intimate relation be- 
 
 XS/AM; VUMSTM. innOKPATOT2, TUV V/cT^c. B/3-X. f. 
 
OF THE TEGUMENTARY MEMBRANES IN GENERAL. 189 
 
 tween the teguments and the mass of the body, and vice versa; 
 a relation which is daily rendered obvious by observation, one 
 which morbid causes are continually putting in action, from 
 the observation of whose symptoms the practitioner endea- 
 vours to profit. 
 
 256. We have already stated that the embryo is wholly 
 formed on these membranes: the vitellar or intestinal mem- 
 brane is the first that appears in the egg; it is by its prolonga- 
 tion towards the stomach, and towards the anus that the intes- 
 tine is formed. The second apparent part is the allantoid or 
 the vesical membrane, by the extension of which the urinary 
 passages and genital organs are formed. The external skin is 
 next produced: at first widely open in front of the trunk, it 
 closes in the median line of the abdomen, and finallj T , round 
 the umbilicus. In the two sexes there is a great difference of 
 conformation in the genito-urinary portion of the teguments, 
 and a difference of development in that of the excretory ducts 
 of the mammae. Besides this, there is a difference of colour- 
 ing and of thickness in the external skin. These differences 
 are well marked in the various races of the human species, and 
 are also visible in individuals. 
 
 257. Morbid changes are very numerous in the different 
 parts of the tegumentary membrane. Accidental, cutaneous, 
 and mucous productions frequently occur. Reproductions of 
 the tegument or cicatrices, are seen daily. Vices of conforma- 
 tion, alterations of texture and functions, accidental produc- 
 tions, analogous or not to the healthy tissue, transformations 
 of tissue, &c. are also frequently observable in the teguments; 
 but their description will be better placed after that of each of 
 these membranes; the same observation will apply to their 
 cadaverous alterations. 
 
 258. The accidental teguments, on the contrary, should 
 be described here, because, on the one hand, their production 
 is very analogous in both teguments; and on the other, because 
 in the production of an external cicatrix, the new tissue, during 
 one period of its formation, resembles the mucous membrane, 
 and at a later one, the skin; and finally, because in some cases 
 we find the appearance and texture of the skin in one part, and 
 
190 GENERAL ANATOMY. 
 
 that of the mucous membrane in another of the same produc- 
 tion. Such as, for instance, the membranes of fistulas. 
 
 Every time that either by mechanical lesion, by the effects 
 of cauterization, gangrene, or ulceration, there is a destruction 
 of the teguments, or even of the subjacent parts to a greater or 
 less depth, a tegument is always produced similar to the one 
 destroyed, or at least very analogous to it, and similar in its 
 whole extent, whatever be the diversity of denuded parts 
 that are to be reclothed by it. After the primitive phenomena, 
 varying according to the causes of the injury, there is a series 
 of secondary ones always similar: they are 1st, the production 
 of a plastic layer like that of agglutination ; 2d, the formation of 
 buds or granulations, and the secretion of pus; 3d, the cessa- 
 tion of this secretion, and the completion of the cicatrix. The 
 phenomena of cicatrization commence by the deposition of a 
 plastic layer similar to that which constitutes the false mem- 
 branes. This layer at first is inorganic, but soon becomes or- 
 ganized, covered with little red, conical granulations, and consti- 
 tuting then the membrane of the fleshy granulations; this mem- 
 brane is cellular, vascular, very contractile, sensible, absorbent, 
 secreting pus, apt to be destroyed by ulceration, and quickly 
 reproduced. This membrane is continually contracting, the 
 secretion of pus gradually diminishes, and finally ceases, when 
 it becomes covered, either with a distinct epidermis, or with 
 mucus, according to the part, and constitutes a new tegument, 
 very analogous, and sometimes absolutely similar to the old 
 one. This membrane, however, besides some slight anatomi- 
 cal differences, is much more susceptible of ulceration than the 
 primitive teguments. 
 
 259. In abscesses, and particularly in chronic abscesses, a 
 membrane is formed which circumscribes the pus, and which 
 strongly resembles the mucous membrane; this resemblance 
 is 'still greater, when the abscess is opened and remains the 
 source of a fistulous ulcer; it is the same with that kind of ul- 
 cers kept up by necrosis, or the presence of foreign bodies; it 
 is also the same with true fistulas, or the accidental canals 
 which arise from a natural mucous cavity. In every case, the 
 passage is lined through its whole extent by a fungous, soft, 
 
OF THE MUCOUS MEMBRANE. 191 
 
 mucous membrane, discovered by Hunter, in fistula in ano. 
 At its orifice in the skin, if it terminates on that surface, the 
 mucous canal of the fistula, to a certain depth, has a distinct 
 epidermis, which is continued with that of the skin. 
 
 SECTION II. 
 
 OF THE MUCOUS MEMBRANE. 
 
 260. The internal tegumentary, or mucous membrane has 
 received the latter name, at first in the nasal fossae (^v|a, nos- 
 trils) on account of the mucus (pvfr pituita] it produces. It 
 constitutes a humid tegument that clothes all the cavities com- 
 municating externally, all of which receive or eject foreign 
 substances. Regarded at first as the particular internal mem- 
 brane of each hollow organ, and having no other name, after- 
 wards called, villous or fungous, pulpy, porous villoso-papilla- 
 ry, in the alimentary canal, pituitary, or mucus in the nose 
 and throat, anatomists were not long in discovering follicles in 
 nearly all its parts, which caused it to receive the generic ap- 
 pellation of glandular, and in remarking the resemblance of 
 the nasal and intestinal mucus, to the unctuous humour of the 
 trachea and bronehiae, and even the analogy of mucus to the 
 epidermis; from this moment the identity of the various parts 
 of this membrane was known. Pathologists, M. Pinel in par- 
 ticular, had already remarked this in treating of catarrh. No 
 general and satisfactory description of this membrane, how- 
 ever, had been given until that of Bichat.* Anatomists and 
 pathologists, have since generally agreed in adopting his ideas 
 on this subject, Gordon excepted, who finds too many essential 
 differences between the various mucous membranes, to include 
 them in one common description. 
 
 261. The mucous membrane forms an internal tegument 
 to all the cavities that open externally; its more important por- 
 tion clothes the whole alimentary canal from the mouth to the 
 
 * TraiM det membranes. Paris, an. viii. 
 26 
 
192 GENERAL ANATOMY. 
 
 anus; the remainder constitutes prolongations or appendages 
 prolonged in a cul-de-sac, more or less extended and rami- 
 fied in the mass of the body, and their orifice terminating 
 either on the external or internal skin. It thus forms an im- 
 mense internal tegument, of much greater extent than the 
 skin. 
 
 262. The mucous membrane, like the skin, presents an 
 adhering and a free surface; the adhering or external surface 
 is generally covered with a particular layer of fibrous cellular 
 tissue, which has been named by Ruysch and other anatomists, 
 the nervous membrane, which Albinus and Haller have de- 
 monstrated to consist of cellular tissue, and which Bichat has 
 called the sub-mucous cellular tissue. This tissue is close, 
 fibrous, white, never contains fat, and rarely any infiltrated 
 serosity; it is traversed by a great number of small branches 
 of vessels and nerves. Several anatomists have assimilated 
 it to the dermis of the skin. However this may be, it is to 
 it, that the hollow organs in a great measure owe their solidity. 
 The mucous membrane is moreover lined throughout the ex- 
 tent of its principal canal and of several of its divisions, by a 
 muscular plane, a kind of internal muscular coat analogous to 
 those muscles we have denominated sub-cutaneous; in some 
 places it is an elastic tissue that covers the mucous membranes, 
 visible in the trachea and the excretory ducts; in others, a 
 true ligamentous tissue, as the periosteum of the nasal fossae, 
 of the sinuses, of the palate, of the alveolar processes, lines 
 this membrane, making of it a fibro-mucous membrane. 
 
 263. The free surface of the mucous membrane presents 
 valvuli, folds and wrinkles, formed by the doubling of the 
 whole thickness of the membrane. The valvuli are formed 
 by folds of the mucous membrane, by the sub-mucous tissue, 
 and by muscular fibres contained in the fold; this is the case 
 in the pylorus, the mouth of the jejunum, in the colon, the ve- 
 lum palati, the orifice of the larynx, &c. The folds contain, 
 in their thickness, sub-mucous tissue only, but they always 
 remain, like the valvuli, and are never effaced : such are the 
 numerous folds of the small intestine which are called valvuli 
 conniventes; the wrinkles on the contrary are accidental or 
 
OF THE MUCOUS MEMBRANE. 193 
 
 momentary folds, in which the mucous membrane is in re- 
 serve for future dilatations of the organs, or, which depend 
 upon the expansion and subsequent contraction of the organ, 
 by which the mucous membrane is made to exceed the mus- 
 cular membrane: such are the longitudinal wrinkles of the 
 oesophagus and trachea, the irregular wrinkles of the stomach 
 when contracted, the regular wrinkles of the vagina and of 
 the neck of the uterus, &c. 
 
 264. The free surface of the mucous membrane presents 
 also cavities or depressions of various kinds, and papillary 
 and villous projections. But these various objects, although 
 generally dispersed throughout the membrane, do not exist, 
 or at least are not equally apparent in all points of its extent. 
 Infundibuliform cellular or alveolar depressions are found on 
 the surface of the membrane: they are found at the maximum 
 of their development in the second stomach of the ruminantia, 
 which on this account is called the honeycomb; they exist also, 
 but much smaller and more microscopical, in a great part of the 
 alimentary canal, and particularly in the oesophagus, stomach, 
 and the colon of man, where they were perceived and pointed 
 out by Fordyce and Hewson, and described and figured by 
 M. Ed. Home. 
 
 265. The follicles* only differ from these alveolar depres- 
 sions in having a very small orifice, a neck more or less pro- 
 longed, and a bottom resembling an ampulla, placed in the 
 sub-mucous tissue where they project. They are formed by 
 a reflection of the membrane, strengthened externally by- 
 dense cellular tissue, and provided with numerous small ves- 
 sels. They are every where to be found, their number, how 
 ever, varies according to the part ; they are, in general, very 
 small, but they vary also greatly in size. Some are simple 
 and separate; others terminate in a common canal of which 
 they arc as it were branches; others again end in a common 
 and dilated orifice, called a lacuna; such is the hole at the base 
 of the tongue, the Iacuna3 of the urethra, rectum, &c.; another 
 
 * Peyer. dc Gltmdulis intestinalium. Amstel. 1681. T. C. Brunner. dc 
 Glandulis duodeni. Francof. 1715. 
 
194 GENERAL ANATOMY. 
 
 set are aggregated, as the caruncula lachry mails, the aryte- 
 noid gland, the aggregated glands of the ilium, &c.; finally, 
 others are compound and have multiplied lacuna or ramified 
 ducts, and greatly resemble glands: such are the tonsils, the 
 molar glands, the prostate, the glands of Cowper, &c. 
 
 266. The little eminences called papilla? or villosities that 
 are seen on the free surface of the mucous membrane appear 
 to be designed, like the depressions of which we have been 
 speaking and to which, in number, they are in an inverse 
 ratio, to increase the surface; but, in the one as well as the 
 other of these dispositions, the texture and functions of the 
 membrane are remarkably modified. These eminences, called 
 villosities, in consequence of the comparison drawn by Fallopius 
 between the internal membrane of the intestines and velvet, 
 and named papillae, on account of their supposed resemblance 
 to a button or nipple, do not essentially differ with each other; 
 both are projections of the membrane more or less fine, and 
 the greater part hardly visible to the naked eye. 
 
 The most voluminous of these elevations are called papillae, 
 such are those that fill the cavity of the teeth, commonly 
 called their pulp; those smaller ones that bristle the two ante- 
 rior thirds of the tongue, and those, still smaller, that are per- 
 ceived on the gland of the penis, of the clitoris, &c. These 
 elevations belong to the corium of the mucous membrane, 
 furnished in these places with a great number of nervous 
 threads and small branches of blood-vessels, among which the 
 little veins present an erectile disposition. In parts provided 
 with papillae, the mucous membrane is furnished with a dis- 
 tinct epidermis, called epithelium, on account of its covering 
 the papillae. 
 
 267. The villosities, whose existence is very general, but 
 which are nowhere more numerous, larger, or more apparent, 
 than in the pyloric half of the stomach, the small intestine, 
 and in the beginning of it in particular, are still smaller than 
 the papillae. 
 
 These villosities, which may with justice be styled the radi- 
 cles of animals ^are, little foliaceous prolongations of the internal 
 membrane of the digestive canal, whose form and length vary 
 
OF THE MUCOUS MEMBRANE. 195 
 
 in the different parts of it, and which, the difference of volume 
 excepted, may be compared to the transverse folds or the val- 
 vuli conniventes of the intestines. The villi* perceived by 
 Fallopius and Azelli, described and represented by Helvetius, 
 Lieberkuhn, Hedwig, Rudolph, Meckel, Buerger and several 
 other anatomises, are found, particularly, in the small intestine; 
 they are not so long and are less numerous in the stomach 
 and colon. To have a fair view of them, it is necessary to 
 take a portion of the intestine unchanged by putrefaction, to 
 open it carefully, to moisten it with drops of water until the sur- 
 face is completely covered by it, and then to examine it through 
 a lens, which will increase its diameter about forty times. 
 
 268. To make this examination as well as others analogous 
 to it, I have used, with much advantage, a little apparatus 
 composed of a glass sphere of small diameter, open on one 
 fourth of its surface, and of an operculum a little smaller than 
 the opening, and of a thin layer of wax. The part, to be exa- 
 mined is to be fixed on the wax with small pins, it is then 
 plunged into water with the open sphere, which is to be filled 
 with that liquid, and afterward, placed on the operculum. The 
 apparatus is now withdrawn, and the object to be examined 
 is thus covered by a little lenticular mass of water, which aug- 
 ments its diameter. 
 
 269. Examined in either of these two ways, the villi ap- 
 pears neither conical, cylindrical, canaliform, nor enlarged at 
 the summit, as many authors have described them, but rather 
 in the form of little leaves or laminulse, whose numbers are so 
 great as to convey the appearance of a luxuriant grass-plot. 
 These little leaves, variously bent and consequently seen in 
 various aspects, appear to have different forms: neither are 
 they everywhere the same: those of the pyloric half of the 
 
 * See among other authors, Helvetius. Mem. de fAcademie des Sciences. 
 Paris, 1721. T. N. Lieberkuhn. de Fair, et ad. Fillos. Intest. horn. Lug-d. 
 Bat. 1744, 4to. R. A. Hedwig. Disquis. Ampull. Lieberkuhnii. physico- 
 micros. Lips. 1794, 4to. C. A. Rudolphi. in Reils Archiv. der physioL IV. 
 et Anal, physiol. abhandl. Berol. 1802. J. F. Meckel in Deutches Archiv. 
 fur die physioL III. H. Buerger. Examen. micros. Villos. intestin. cum 
 iconibus. Halae, 1819 8vo. 
 
196 GENERAL ANATOMY. 
 
 stomach and of the duodenum, broader than they are long, con- 
 stitute little blades; those of the jejunum, long and narrow, 
 are better entitled to the name of villi, and near the end oi' 
 the ilium, as well as in the colon, where they scarcely project 
 at all, they again become laminae. The villi are semi-dia- 
 phanous, their surface is smooth, and we can neither perceive 
 on their surface the openings which have been admitted with- 
 out ever being able to agree as to their number, nor in their 
 thickness, the cellular ampullae, nor vascular texture that has 
 been described; we only perceive in their gelatiniform sub- 
 stance, microscopic globules arranged in a linear series, and 
 at their base, small branches of blood-vessels and lymphatics 
 of an excessive tenuity. 
 
 270. The anatomical texture and composition of the mu- 
 cous membrane present many varieties or differences, in differ- 
 ent parts. The foliated disposition can not be demonstrated 
 in all parts of the membrane, and, on the contrary, manifestly 
 exists in some points of it. 
 
 In the greater part of its extent the membrane consists 
 solely in one spongy tissue, more or less soft and very varia- 
 ble as to thickness. With respect to this we must observe, 
 that in the very young foetus, and in the inferior animals of 
 the series, the external skin itself presents this character of 
 simplicity. As to the thickness, it diminishes successively 
 from the gums, palate, nasal fossa?, stomach, intestines, biliary 
 and urinary bladders, to the sinuses and divisions of the ex- 
 cretory ducts, where its tenuity becomes extreme. It is in 
 this essential part of the membrane and at its surface, that the 
 last divisions of the vessels ramify; it is from its free surface 
 that arise the villosities. 
 
 171. But slight traces of a distinct layer of the mucous 
 body is to be found in it, unless we regard as such, the layer 
 of coagulable fluid, that separates the papilla? of the tongue 
 from the epidermis, or consider the gelatiniform surface of the 
 villosities as belonging to it, or admit as proofs of its exist- 
 ence the ephelides or variously coloured spots that are some- 
 times found in the teguments of the glans penis and of the 
 vulva, as well as the accidental imperfect horny productions, 
 
OP THE MUCOUS MEMBRANE. 197 
 
 which are still more frequently observed in the same parts in 
 a form called warts. 
 
 The existence of the epidermis is much more manifest, with- 
 out, however, being general. 
 
 272. The epidermis or epithelium is very apparent at the 
 orifices of the mucous cavities; it is less so in their deeper 
 parts, and finally ceases to be apparent. Does it however 
 exist there? Haller and others have thought that it does, 
 and that the accidental membraniform excretions are a proof 
 of it. Every pathologist of the present day, knows that such 
 excretions are generally the result of a plastic inflammation, 
 and sometimes of eschars. The same conclusion has been at- 
 tempted to be drawn from the formation of an artificial anus, 
 accompanied with a retroversion of the intestine in which the 
 epidermis becomes very apparent; but this only proves that 
 the free surface of the mucous membrane is covered with a 
 substance which is very analogous to the epidermis, and which 
 is very much disposed to undergo this transformation. By 
 depending upon what observation teaches, and, by the use of 
 dissection, decoction and putrefaction, to separate the epithe- 
 lium, it is found very distinct as far as into the esophagus, ter- 
 minating suddenly at the union of this canal with the stomach; 
 it is also very distinct in the vagina, terminating all at once 
 on the lips of the os uteri, interruptions long ago known, 
 and erroneously adduced by some modern writers as proofs 
 of the interruption of the mucous membrane itself. In 
 other parts, as in the nasal fossae and the inferior extremity 
 of the alimetary canal, their diminution of the appearance of 
 the epithelium is gradual, insensible, and it is impossible to 
 assign its limits with exactness. In those places where it is 
 distinct, it dips, becoming thinner and thinner, into the folli- 
 cles, where it is lost. In places deprived of a distinct epithe- 
 lium, the free surface of the membrane is covered with a 
 mucous varnish, which from the time of Vesalius and even 
 of Rhazes, has been compared to the covering or tinning of 
 vessels; and of which Glissen has remarked, at least with re- 
 gard to its functions, the analogy with the epidermis. 
 
 273. The cellular tissue which forms the corium of the 
 
198 GENERAL ANATOMY. 
 
 mucous membrane, has not a regularly aereolar disposition 
 like that of the cutaneous dermis; it is rather spongy or 
 fungous. Blood-vessels and lymphatics abound in it. Its 
 nerves generally arise from the great sympathetic and the par- 
 vagum: at all the natural orifices, the mucous membrane is 
 supplied with nerves from the medulla spinalis. 
 
 274. The colour of the mucous membrane varies from 
 white to red, and besides the intermediate shades, it presents 
 other differences of colour. This colour is owing, at least in 
 a great measure, to the blood which circulates through its 
 thickness, for asphyxia or syncope, either imparts a brown tint 
 to, or instantly deprives of all colour, the parts of this mem- 
 brane which from their situation are visible. Its consistence 
 is, in general, soft and fungous-like. It varies greatly in thick- 
 ness, and its tenacity is moderate. The mucous membrane 
 is quickly changed by putrefaction, and the sub-mucous tissue 
 still more so, for it is then very easily detached. Whether 
 it is susceptible of being converted into leather by the action 
 of tanning, is not known. 
 
 275. Its force of formation is highly developed; when de- 
 stroyed, it is soon reproduced with all the characteristics of 
 the natural tissue. It is slightly irritable and possesses a 
 higher degree of tonic contractility than the cellular tissue. 
 Its sensibility is vague and obscure throughout the greater 
 part of its extent. Even when inflamed it does not, general- 
 ly, occasion much pain. It is very sensible at the natural 
 openings; and at the entrance of the alimentary and perspira- 
 tory canals, it is the seat of a special sensibility. 
 
 276. Its organic actions or functions are: 
 
 1st. Absorption, which is very active and general, and of 
 which the villi are the most active, but not the only, agents. 
 
 2d. Secretion, which is perspiratory and follicular, and 
 whose products, differing according to the parts, are all, how- 
 ever, known by the name of mucosities. 
 
 3d. Movements of tonic contraction, strengthened in many 
 places by the action of the elastic tissue and even by that 
 of the muscular fibres, with which, in many parts, this mem- 
 brane is surrounded. 
 
OF THE MUCOUS MEMBRANE. 199 
 
 4. Sensations, more or less distinct or obscure, general or 
 special, and feelings of want, or of appetites. 
 
 277. The mucosities or the mucous humours that are 
 found on the surface of the internal tegument, are for the 
 most part composed of mucus. Animal mucus* very ana- 
 logous to vegetable mucilage, but containing nitrogen in addi- 
 tion, is one of the immediate principles of animals. It is 
 found both internally, in the product of the mucous secretion, 
 and externally in the epidermis, hairs and horny parts, of 
 which it forms a considerable portion. In a pure and liquid 
 state, it is white, viscid, transparent, inodorous, and insipid; it 
 contains nine-tenths of its weight of water; it is insoluble in 
 alcohol, soluble in acids, not coagulable like albumen, and not 
 congelable like gelatine; it is precipitated^ by the acetate of 
 lead; in a dry state it is semi-transparent, fragile, insoluble 
 in water, soluble with difficulty in acids. 
 
 M. Berzelius has proved the identity of the mucus of the 
 nose and trachea, and found it composed as follows: water, 
 933.9; mucous matter, 53.3; hydrochlorate of potash and 
 soda, 5.6; lactate of soda and animal matter, 3.0; soda, 0.9; 
 phosphate o soda, albumen and animal matter, 3.3. 
 
 In the analysis of the other mucosities given by this savant, 
 and in those of Messrs. Fourcroy and Vauquelin, there are con- 
 siderable differences, some of which depend on the difference 
 of parts whence the mucosity was taken, and where it had 
 been mixed with various matters, and others on the difference 
 of the individuals affected with different diseases. In fact, 
 although mucus is always identical, mucosity is neither al- 
 ways nor everywhere the same; generally it coagulates milk. 
 
 278. The functions of the mucous membrane are very 
 closely connected with those of the other parts. In a healthy 
 state, the nervous action, the circulation, the functions of the 
 skin, &c. have a manifest influence on the functions of the 
 mucous membrane, and vice versa. In a state of disease, the 
 mucous membrane produces very remarkable sympathetic 
 effects, and experiences also those produced by other parts. 
 
 * See. Fourcroy and Vauquelin, Annahs du Mus. cThist. nat. vol. xii. 
 Bostock, Medico-Chir. Transact, vol. iv. Berzelius, ibid vol. iii. 
 27 
 
200 GENKKAL ANATOMY. 
 
 279. The origin of the mucous membrane, from the very 
 beginning of the egg and its development in the embryo, have 
 been already pointed out. (256.) "There yet remains unde- 
 scribed the formation of the villosities; it is to M. Fr. Meckel 
 that we are indebted for our knowledge of this point of em- 
 bryogeny. The villosities are formed at a very early period. 
 From the beginning of the third month, they are visible in the 
 form of closely-joined, longitudinal plaits. These plaits after- 
 wards present, on their free edge, notches like the teeth of a 
 saw, which successively augment in depth; and towards the 
 end of the fourth month, the plaits are replaced by that multi- 
 tude of little eminences which constitute the villosities. They 
 are at first tolerably large and very distinct till the seventh 
 month. In the commencement they are as numerous, although 
 shorter, in the large intestine, as in the small one. Those of 
 the large intestine afterwards diminish in number till birth. 
 We should observe that in reptiles, these villosities are re- 
 placed by little longitudinal folds. 
 
 280. The differences of the mucous membrane, as regards 
 the sexes, races, and individuals, are not such as can be gene- 
 rally described, excepting always the difference of conforma- 
 tion in the genital and urinary organs of the two sexes. The 
 mucous membrane of the digestive canal, is thicker in the hu- 
 man species than in the mammiferous carnivora, but thinner 
 than in the herbivora; the peritoneal covering of the intestine, 
 on the contrary, is thinner in the herbivora, and thicker in the 
 carnivora than in man. 
 
 281. The teeth, as has been already stated, are appendages 
 of the mucous membrane of the mouth, -prolonged into the al- 
 veoli, as far as the papilla or dental pulp, appendages which 
 may be compared to the hairy appendages and horns of the 
 external skin. 
 
 282. The mucous membrane is subject to extremely varied 
 and numerous morbid alterations: it participates in the primi- 
 tive and acquired vices of conformation, of the organs of which 
 it is a part, as well as of their displacements. It alone also 
 undergoes displacements, more or less extensive, through the 
 loosened texture of the sub-mucous tissue, particularly in the 
 
OF THE MUCOUS MEMBRANE. 201 
 
 oesophagus, intestine, and bladder, constituting a false diverti- 
 culum. The mucous membrane also presents other prolonga- 
 tions, depending on its elongation and the laxity of the sub- 
 mucous tissue; such are certain prolongations of the plaits or 
 valvuli conniventes, of the uvula, prolapsus ani, of the vagina, 
 &c. Particular polypi, also appears to be a mere vegetation, 
 or hypertrophy of the membrane and sub-mucous tissue; but 
 generally there is an accidental tissue produced. Tumours of 
 the. eye-lids, of the amygdalae, and of the uvulae vesicae, should 
 be regarded as a hypertrophy of this membrane and its folli- 
 cles. 
 
 283. The mucous membrane is very subject to a serous 
 and mucous discharge, which constitutes the phlegmorrhagies 
 and blennorrheae without inflammation. The sub-mucous tis- 
 sue itself, although rarely, is subject to an oedema or serous 
 infiltration. This membrane is frequently the seat of hemor- 
 rhage or bloody discharges; the sub-mucous tissue is also 
 sometimes in a state of ecchymosis. It is also certain that it is 
 the seat of a gaseous evolution or secretion. 
 
 2S4. Inflammation is very common in it, under all its 
 forms. Its anatomical characters, are increased redness, some- 
 times verging to a brown; a degree of thickening, generally 
 slight, but variable, and proportioned to the duration of the 
 disease; a softening more or less marked; and sometimes an 
 enormous augmentation of the villosities. The most usual re- 
 sult of this inflammation, is an augmentation of the quantity 
 of the mucus, and of a change in its qualities. This catarrhal 
 inflammation often degenerates intophlegmorrhea or blennor- 
 rhea. Suppurative inflammation also frequently occurs in it; 
 the membrane without being ulcerated secretes mucus and 
 pus, or even pure pus alone. Abscesses are also sometimes 
 found in the sub-mucous cellular tissue. The plastic inflam- 
 mation is less frequent. It is, however, frequently observed 
 in the trachea and bronchiss, where it constitutes croup, and 
 not unfrequently in the alimentary canal, the intestines, blad- 
 der, urethra, and sometimes even in the eyes. The organ iza- 
 ble matter is usually excreted in pieces, or membranes, of suf- 
 ficient size and consistence to have been taken for the internal 
 
202 GENERAL ANATOMY. 
 
 membrane of the stomach, or of the bladder, &c. ; or the patient 
 dies before its organization; at other times, on the contrary, the 
 new membrane becomes organized, and united to the surface 
 of the old one, or it contracts adhesions with itself, and thus 
 forms mucous bridles in greater or less number, which tra- 
 verse and contract more or less the cavity they occupy. 
 
 The inflammation of the mucous membrane is not always 
 erythematous, and uniformly extended over its surface; it 
 sometimes assumes the form of red isolated patches, and often 
 that of exanthematous buttons, whether the little elevations be 
 separate or confluent. It is known that this" may be some- 
 times, but not always, seen upon the mucous membrane of the 
 digestive and respiratory canals, of individuals who have died 
 of small-pox, and that it has in that case been regarded as an 
 internal variola.* This internal exanthema, which appears 
 to consist in an inflammation confined to the follicles, has been 
 particularly observed by Mr. Bretonneau in an epidemic en- 
 teritis, whose description, it is to be regretted, he has not yet 
 published. 
 
 286. Gangrene, sometimes, and ulceration, frequently, take 
 place in the mucous membrane, particularly after the exan- 
 thema of which we have been speaking. After either of these 
 causes of destruction if the individual survives, a new mem- 
 brane is soon formed in the destroyed places, having all the 
 characters of the old one. We have already said, that the 
 membranes of abscesses, those of chronic abscesses particular- 
 ly, and above all that of fistulas in the neighbourhood of the 
 anus, as well as that of the fleshy buds, is a mucous mem- 
 brane, like that of fistulas. The serous and synovial mem- 
 branes which suppurate, assume the same character. When, on 
 the contrary, a mucous cavity becomes the seat of dropsy, the 
 membrane assumes the aspect of the serous membranes: this is 
 seen to happen in the fallopian tubes, the maxillary sinuses, 
 and less completely in the gall bladder, and the duct of the 
 sub-maxillary gland. Certain cysts, also, by their texture and 
 
 * See Wrisberg. in sylloge Comment, p. 52, G. Blane in Transact, for the, 
 improvement of med. and chirur. knowL vol. iii. p. 423 428. 
 
OF THE MUCOUS MEMBRANE. 203 
 
 humours, belong to the mucous membrane: such in particular 
 are the atheroma; but as will be seen hereafter, the atheroma 
 are often follicles of the skin, and in that case it is a slight 
 transformation only. 
 
 287. The mucous membrane is subject to various sorts of 
 accidental productions, either healthy or morbid. Sometimes 
 the natural mucous membrane of the vagina, during a prolapsus, 
 that of the prepuce in phymosis, that of fistulas, and particu- 
 larly in the lungs, become more or less perfectly cartilaginous, 
 and sometimes even bony, either by transformation, or by a 
 new production. Serous cysts have sometimes been observed 
 both in its thickness and beneath it. Accidental hairs are 
 sometimes found on the surface of this same membrane. Im- 
 perfect horny productions are likewise found in it. Although 
 fatty tumours are rare in the sub-mucous tissue, they have been 
 found in it: erectile productions in this same sub-mucous tissue 
 are observable, frequently about the anus, and sometimes in 
 other parts of the intestinal canal. Finally, morbid produc- 
 tions are frequently remarked there. 
 
 288. The cadaverous changes of the mucous membrane, 
 have been already partly indicated 274. This membrane, soon 
 after death, becomes coloured by the infiltration of the hu- 
 mours that cover it. Thus in the intestine opposite the nates, 
 it is yellowish; it presents livid marks, corresponding to the 
 larger sub-mucous veins, and becomes greenish in the gall 
 bladder, &c. 
 
 In certain kinds of death, and in some internal parts, it is the 
 seat of sanguineous, or sero-sanguineous congestions. In death 
 from apoplexy, hydrothorax, and particularly from strangula- 
 tion, in a word, in all those cases where there is a difficulty of 
 breathing previous to death, it frequently happens that the 
 congestion, after having been at first confined to the sub-mu- 
 cous veins, and then to the vessels of the membrane itself, 
 finally proceeds to hemorrhage in the stomach and intestines, 
 as Boerhaave and Morgagni had already stated, as M. Yelloly 
 has observed,* and as I myself have several times seen, after 
 
 * MedicO'chirurg. Transact, vol. iv p. 371. 
 
204 GENERAL ANATOMY. 
 
 this kind of death, both in men and animals This congestion 
 is easily distinguished from inflammation by the absence of all 
 morbid, mucous, purulent or plastic product on the surface of 
 the membrane, by the other cadaverous phenomena depending 
 on the settling of the blood in the right side of the heart, and 
 especially by the state of the skin, which, like the mucous 
 membrane, presents livid spots and sometimes echymoses. 
 
 SECTION III. 
 
 OF THE SKIN. 
 
 289. The skin, pellis, cutis, corium^ 6tp,ua, constitutes the 
 external tegument; it is a compound membrane furnished with 
 various appendages, which envelops and protects the body, 
 and has other important functions. 
 
 290. Galen has made some remarks upon the structure of 
 the skin, and particularly upon its functions. The anonymous 
 author of the Anatomical Introduction, and after him, Avicenna, 
 were the first who spoke of the fleshy panicle, panniculus carno- 
 sus. Vesalius and Columbus still thought the skin was perforat- 
 ed by the natural openings: but Casserius, as we have already 
 seen, had observed that it was continued into the nostrils and 
 mouth; we are also indebted to him for a figure of the epider- 
 mis, separated from the dermis. J. Fabricius has given a very 
 exact and detailed account of the various appendages of the 
 skin of animals; since then, the observations of anatomists 
 upon this organ, have been greatly increased.* 
 
 * M. Malpig'hi, de lingua extrc.it. epist. dc Externo tactu organo epist., iti 
 op.omn. torn ii. J..M. Hoffmann, de. cuticula et cute. Altd. 1685. Littre, 
 Obs. sur les differentes parties de la peau, etc. Acad. roy. des Sci. 1702. < 
 F. de Riet, de Organo tactts. Lug-d-Bat. 1743. J Fantoni, de Carports inte- 
 gumentis, etc. Turin, 1746. Lecat. Traite des sens. Cruikshank, Experi- 
 ments on the insensible perspiration, etc. Loud. 1795. C. F. Wolff, de Cute, 
 in nov. Com. Petrop. vol. viii. G. A. Gautier, Rechcrches sur forgane cutanc. 
 Paris, 1811. Dutrochet Obs. sur la struct, dc la pcau. Journ. compl. 
 vol. v. J. F. Schroter, das Memchlich Geftihl, dc. Leipzig, 1814. Law- 
 rence in Rees* Cyclopaedia. Seller in Anat. phys'wl. RealworterbbcH- 
 
UF THE SKIN IN UKNKKAL. 205 
 
 ARTICLE I. 
 OF THE SKIN IN GENERAL. 
 
 291. This membrane, extended over the whole surface of 
 the body, whose figure in many of the inferior animals it deter- 
 mines, and receiving on the contrary the form of man and the 
 other vertebrata, is in fact moulded on the subjacent organs, 
 permitting their more strongly marked projections to be seen. 
 Everywhere continuous to itself, an apparent interruption is 
 only to be found in various places on the median line, called 
 the raphe, and which indicates it to have consisted originally 
 of two separate halves. This raphe is well marked in those 
 places where the two halves unite last, and where anormal 
 divisions are most usually found, as in the upper lip, in the 
 perineum and below the umbilicus. The skin seems perfo- 
 rated, but is not, at the apertures of the digestive canal, and 
 the orifices of the respiratory, urinary and genital organs, 
 places where it is reflected and continues on, changing its 
 character with the internal skin. It is the same at the rneatus 
 auditorius externus, where it sends a cutaneous prolongation 
 to the eyes and the ducts of the mamma?, into which it trans- 
 mits others of a mucous nature. 
 
 292. The skin presents two surfaces. The free surface, 
 which is external and in contact with the atmosphere, pre- 
 sents various objects for consideration: we there see wrinkles 
 or folds more or less deep, some of which depend on the sub- 
 cutaneous muscles situated on the he.ad, neck, and about the 
 anus, where the skin can not accompany their contraction; it 
 is the same with respect to the wrinkles on the scrotum occa- 
 sioned by the contraction of the subjacent tissue; others an- 
 swer to the articulations and are caused by their motions: 
 such are those of the hands, feet, &c. ; others again depend 
 upon emaciation and muscular atrophy, when these phenome- 
 na are rapidly produced and at a sufficiently advanced period 
 of life for the skin to have lost its contractility. The surface 
 of the skin presents, besides, small wrinkles, in the palm of 
 the hand and sole of the foot, that are peculiar to the epider- 
 
206 GENERAL ANATOMY. 
 
 mis; they are salient lines separated by depressed ones, various- 
 ly directly and formed, and which are made by series of pa- 
 pillae On the back of the hand, and on the forehead they are 
 polygons; on the cheeks and breast, mere points and rudiments 
 of stars, &c. We also find on the free surface of the skin, 
 small round openings that are every where distributed, and 
 particularly abundant in the face: they are the orifices of the 
 sebaceous follicles. There are others still smaller, microsco- 
 pic openings or apparent pores of the epidermis, but in 
 reality, infundibuliform depressions, terminating in a cul-de- 
 sac. This surface is in general tolerably smooth; it is slight- 
 ly moistened by the transpiratory fluid and the sebaceous 
 matter. 
 
 293. The deep or adhering surface of the skin is con- 
 nected, in general, with the subjacent parts by loose cellular 
 tissue, which permits a mutual sliding between the skin and 
 the parts it invests. Sub-cutaneous bursae mucosse, in some 
 places, interrupt the continuity of the cellular tissue, and 
 greatly increase the motility of the skin and parts beneath. 
 In other places, on the contrary, the cellular tissue is dense, 
 firm and scarcely distinguishable from the skin: it is soon 
 the head, back of the neck, back, and abdomen. In others 
 again, it is by fibrous or ligamentous tissue that the skin ad- 
 heres to parts beneath; this is the case at the wrist, instep, 
 palm of the hands, sole of the foot, and particularly under the 
 heel. Adhesion is effected in some places by means of a 
 reddish, cellular, semi-muscular tissue, if I may be allowed 
 so to call it; such is the dartos in the scrotum and the labia pu- 
 dendi. Finally, in some places it is the muscles that line 
 the skin attached to them; such are the sub-cutaneous mus- 
 cles of the cranium, of the face, of the neck and of the hand. 
 The fleshy panicle of the mammiferous animals, more high- 
 ly developed than that of man, in the face excepted, is analo- 
 gous to the sub-cutaneous muscles of the latter. . The anato- 
 mists of the middle ages have strongly doubted or denied its 
 existence in man; that it does exist, is evident, but its extent 
 is but small. In many places the sub-cutaneous cellular tissue 
 is mixed with adipose tissue, and these two penetrate into the 
 
OF THE SKIN IN GENERAL. 207 
 
 thickness of the skin together. The sub-cutaneous cellular 
 tissue is traversed by large veins, by numerous arteries, lym- 
 phatics and nerves. 
 
 294. The cutaneous or sebaceous follicles* bear the strong- 
 est resemblance to the mucous follicles. 
 
 They exist throughout the whole extent of the skin, at least 
 it is so admitted, the palm of the hand and sole of the foot 
 excepted. Their existence is conceded, because the whole 
 surface of the skin is covered with the sebaceous humour;* 
 because by careful dissection, aided by a lens, they are dis- 
 covered in places where they are excessively slender; and 
 because certain morbid changes render them evident in places 
 where they are not otherwise perceptible. They are particu- 
 larly abundant where there are hairs, in the vicinity of orifices 
 and in the folds of the groin and axilla. They are placed in 
 the thickness of the skin or beneath it; an excellent view of 
 them may be attained by cutting through the skin obliquely. 
 Their orifices form tolerably distinct pores on the surface. 
 They are about the size of a grain of millet, or even smaller; 
 they vary in size; those of the nose are tolerably large, in the 
 cheeks they are much smaller. Their figure is that of a little 
 ampulla. They are generally simple and separate; those of 
 the nose, however, are very closely approximated; some of 
 them are confluent, or compound. They consist in a little 
 ampulla formed by the skin, thinned, reflected, and furnished 
 with numerous vascular ramusculi. They contain an oleo-al- 
 buminous matter that differs a little in the various regions of 
 the body. 
 
 295. The anatomical texture and composition of the skin, 
 are delicate points of anatomy, that have greatly exercised the 
 patience of observers, and upon which they are far from agree- 
 ing. From a very early period, it was seen, that the skin 
 was composed of two layers, one thick and deep, the other 
 thin and superficial. Malpighi perceiving, that in a bullock's 
 tongue, the papilla of the derm is are separated from the epi- 
 
 * J. Ch. Th. Reusse, prseside Autenrieth, de Glandulis sebacefs dissert, etc, 
 Tubingoe, 1807. 
 
 28 
 
208 GENERAL ANATOMY. 
 
 dermis by a mucous or glutinous layer, which fills up the in- 
 tervals like a net-work, transferred that layer, by analogy, to 
 the skin of man; Ruysch afterwards gave a figure of this net- 
 work. From that period anatomists have been singularly di- 
 vided as to the existence of this membrane: some denying it 
 entirely, and admitting only the dermis and epidermis as con- 
 stituents of the skin; others admitting its existence in the co- 
 loured race only; others again improving upon Malpighi, and 
 admitting of several layers in the mucous body of the skin, as 
 many, as it were, as there are anatomical elements in that 
 membrane, or as it exercises functions. 
 
 296. The blood-vessels, lymphatics, and nerves of the 
 skin penetrate, as they divide, through the areola of the der- 
 mis: supported by a fine cellular tissue which surrounds them, 
 they thus attain its superficies, where they are increased to 
 myriads, which by their ultimate divisions constitute the pa- 
 pillae and the vascular net- work. As relates to the disposition 
 of these parts, and particularly of the vessels, it has been gene- 
 rally conceded that they are foreign to the dermis, and that 
 they merely traverse it to form the vascular net-work above. 
 M. Chaussier, on the contrary, admits that all the anatomical 
 elements of the skin are united in the dermis itself. Gordon 
 even goes so far as to say that the injected dermis is every 
 where equally vascular, as much so on its deep surface as on 
 its superficies. To say that the vessels are foreign to the der- 
 mis, and that they merely form a sub-jacent layer to it, would 
 be incorrect; but it would be equally so to affirm, that the ves- 
 sels are as much divided, and are as numerous on the deep face 
 of the dermis, as they are on its opposite one. The vessels 
 divide and ramify in the dermis, as they penetrate into its 
 thickness, and their last divisions, prodigiously multiplied, are 
 distributed in the external surface of that membrane, and in 
 the eminences that cover it, parts, consequently, much more 
 vascular than the deep face. It is precisely the same as re- 
 gards the nerves. 
 
 297. The dermis or corium, corium, derma, vera cutis, 
 is a fibro-cellular membrane, which constitutes the deep and 
 principal layer, and almost all the thickness of the skin. Its 
 
OF THE SKIN IN GENERAL. 209 
 
 internal face, which is that of the skin, presents, in general, 
 conical alveolar openings, directed ohliquely into the thickness 
 of the membrane. These areolae, which are very large in the 
 dermis of the hand, of the sole of the foot, of the back, of the 
 abdomen, of the limbs; narrower in the neck, breast, and face 
 particularly, are nearly invisible in the back of the hand and 
 foot, forehead, scrotum and labia pudendi. The edges of these 
 areolae are continued, the first and largest along with the sub- 
 cutaneous fibrous tissue; the second with the more or less dense 
 cellular tissue; the last or narrowest, with the very loose tissue 
 that is found in the regions where they are observed; the areola 
 themselves are filled with an adipose cellular tissue, and are 
 traversed by the nerves and vessels of the skin. The bottom 
 of these alveolar cavities is perforated by very small holes, 
 which correspond to the superficial face of the dermis. This 
 face tolerably smooth, in general, presents, in various places, 
 little papillary eminences, that are much more apparent on the 
 denuded dermis, than when seen through the epidermis. 
 
 298. The papillary body, and the vascular net-work of the 
 skin, which have been unhappily described as being distinct 
 layers of this membrane, belong to the superficial face of the 
 dermis. The papillae* discovered by Malpighi, and since ac- 
 knowledged, figured, and described by Ruysch, Albinus, and 
 many other anatomists; lately described by Gautier, under the 
 name of buds: and doubted by Cheselden and others, are very 
 diminutive projections or eminences, generally conoid on the 
 surface of the dermis ; perfectly visible on the tongue, ar- 
 ranged in double lines, and very distinct in the palms of the 
 hands, soles of the feet, and pulp of the fingers; still distinct, 
 but irregularly distributed in the nipple and lips; but so ex- 
 tremely small and undistinguishable in the rest of the skin, that 
 they have been admitted to exist there more from analogy, 
 than from actual observation, and that they are confounded in 
 the surface of the dermis in a vascular and nervous net-work. 
 These papillae, in those places where they are very distinct, 
 
 * Hintze, de papillis cutis tadui inservientibus. L. B. 1747 Albinus. JLcad. 
 annot, lib. iii. cap, ix. et xii. 
 
210 GENERAL ANATOMY. 
 
 evidently consist of a very soft, very cellular projection of the 
 clermis, penetrated by numerous nervous threads, deprived of 
 the neurilema, and of vascular ramusculi, and having an erec- 
 tile disposition which will be described hereafter (chap. iv). 
 In those places where the papillae are less distinct, although 
 the texture and composition of the dermis are essentially the 
 same, there are fewer nerves ; the vessels, which are very 
 abundant, form a net-work. The blood penetrates constantly, 
 but in variable quantities into the vessels of the dermis. In 
 echymosis of the skin it goes still further, and passes into the 
 mucous body. Fine and penetrating injections, after filling 
 the papillary and vascular body of the skin, sometimes spread 
 beyond it* 
 
 299. The texture of the dermis is that of an areolar web 
 more or less close: the fibre that forms it is peculiar to it. It 
 was considered by the older anatomists as intermediate to the 
 muscular fibre, and the aponeurotic tissue. Some have stated 
 it to be altogether cellular, others ligamentous. Even quite 
 recently, M. Osiandert has maintained that it is distinctly mus- 
 cular on the internal face of the skin. His observations were 
 made on the skin of the abdomen in women who died in par- 
 turition. The tissues to which it bears the greatest resem- 
 blance by the ensemble of its characters, are, the cellular and 
 fibrous tissues. 
 
 300. The dermis is white: its external surface is more or 
 less reddish, according to the greater or less quantity of blood, 
 remaining in its small vessels. Its thickness is not every 
 where the same, varying from one line and a half, to a fourth 
 of a line. In the trunk it is generally greater behind than be- 
 fore ; in the limbs more so externally, than internally. The 
 dermis is particularly very thin in the eye-lids, mammae, and 
 the organs of copulation; very thick, on the contrary, in the 
 palm of the hands, and above all, in the sole of the foot. It has 
 a semi-transparency which renders the colour of the sub-cu- 
 taneous veins visible through the skin. It has a power of re- 
 
 * See Frochaska, disquisitio anat, phyn. or%anismi &c. Vienna:, 1812. 4, 
 f Commentationcs gottingcnses recentiores. Vol. iv. 1820. 
 
OF THE SKIN IN GENERAL. 211 
 
 sistance or cohesion, which renders it, in the mechanical arts, 
 fit for strong bands. It is submitted in the arts of the tanner, 
 currier, &e. to various processes which prevent its putrefac- 
 tion, and increase its density or flexibility, &c. It contains, 
 naturally, a great quantity of moisture, whose abstraction ren- 
 ders it yellow and elastic. Decoction reduces it into glue or 
 gelatine. Besides its extensibility and retractility, which are 
 very great and which continue after death, it possesses, during 
 life, a very evident tonic power of contraction, although in a 
 much smaller degree than the muscles. It is this contraction 
 which produces what is commonly called goose-flesh. It is 
 its external surface that is the seat of the sense of touch. The 
 dermis 1 is the support of all the rest of the skin; the corpus 
 mucosum is placed on its surface. 
 
 301. The corpus mucosum, of Malpighi,* reticulare cor- 
 pus^ rete glutinosum malpighianum^ is a very thin layer, of 
 a semi-liquid cellular tissue, which clothes the papillary surface 
 of the dermis, separates it from the epidermis, adheres closely 
 to each of them, and is the seat of colouring matter. This part 
 of the skin, indicated by Malpighi, well observed by Meckel 
 and Albinus, acknowledged by most anatomists, at least in the 
 negro, denied, however, by some of them, particularly by Bi- 
 chat, M. Chaussier, Gordon, and M. Rudolphi, can not, it is 
 true, be isolated by dissection, but may be seen in various cir- 
 cumstances. Whenever, either in life or death, the epidermis 
 is separated from the dermis, we can perceive on one or the 
 other, and sometimes on each of these membranes a mucous 
 layer, which covers the papillary eminences, and fills up the 
 spaces between them. This intermediate membrane, is par- 
 ticularly visible in the negro, very visible also in the black 
 spots of the white man, and even very distinct on a piece of 
 white skin, in the collection of Hunter. This layer, extremely 
 thin on the summits of the papillae, and less so in the inter- 
 vals, has the appearance of a net-work, but is not perforated. 
 
 * See Mecke], Rechcrches anatonu'gues sur la nature de Fcpidcrme et du 
 reseau qu'on appclle malphigien, Mem. de Pacad.. roy. des sc. de Berlin, ann. 
 1753. Albinus, Acadcm. annot. lib. i. cap. i. v. 
 
212 GENERAL ANATOMY. 
 
 Those who admit of only two membranes in the skin, consi- 
 der it as the deep part of the epidermis. This mucous body, of 
 the nature of which it is difficult to form an exact idea, appears 
 to consist of a plastic liquid or a semi-organized cellular tissue. 
 Neither the blood, nor injections show any vessels in it; 
 liquids penetrate into it, however, but they seem to be im- 
 bibed by it, or to be contained in peculiar interstices. Nerves 
 are unknown in it, and it is by a pure allegation that Mr. Gall 
 assimilates it to the grayish substance of the brain. This 
 membrane forms a humid varnish which covers the papillary 
 and vascular surface of the dermis. Substances which enter 
 into, or depart from the economy by the skin, traverse it, it 
 is the seat of colour, and that of the horny, scaly, &c. produc- 
 tions, that exist naturally in the skin of animals, and in some 
 part of that of man, as well as of those that are accidentally 
 developed there. This membrane, which is so thin, and whose 
 existence has even appeared dubious, seems, in some animals, 
 and even in man, at least in some parts of the body, and in cer- 
 tain cases, to be found of several superincumbent layers. 
 
 302. An anonymous author had already pointed out this 
 arrangement. Cruikshank observed it in a negro dead of 
 small-pox; Bay ham on the injected skin of a white man, in 
 another case of disease ; Gautier, by various processes, has de- 
 monstrated it on the skin of the negro, and M. Dutrochet on 
 the skin of animals. This is a sufficient number of observa- 
 tions, to demand an examination before we reject them: 1st, on 
 the papillary surface of the dermis, there is a very thin, co- 
 lourless, transparent layer, particularly distinguishable under 
 the scales and the coloured horns of animals, in the negro and 
 even in the white man, but under the nails only; 2d, a co- 
 loured layer very distinct in negroes, in whites marked with 
 coloured ephelides, and much less so where the skin is white; 
 it is often united to the following; 3d, a superficial colourless 
 layer, more or less soft or encrusted with a horny or calcarious 
 substance; it is distinct in several animals, slightly in the 
 negro, not at all in the white man, except in the nails, hairs 
 and accidental horny productions. This layer is directly co- 
 vered by the epidermis. 
 
OF THE SKIN IN GENERAL. 
 
 303. The pigment of the skin 1 ' is chiefly seated in the 
 corpus mucosum and particularly in its middle layer, but the 
 external surface of the dermis and the internal one of the epi- 
 dermis, also partly partake of it. Anatomists prior to Mal- 
 pighi, arid some even since, place its seat in these two mem- 
 branes, particularly in the latter. The colouring matter exists 
 in men of every race, albinos excepted. It is only in the 
 negro, however, that it can be distinguished, clearly, from 
 the rest of the skin. Malpighi had only announced, that the 
 colour of the skin had its seat in the rete mucosum; Littre had 
 tried, but in vain, to obtain the colouring matter, separately, 
 by submitting the negro skin to maceration, in order to swell 
 the mucous body, and thus to separate the epidermis from the 
 dermis. Although the corpus mucosum is soft and liquefia- 
 ble, we can succeed in separating from the skin of the negro 
 scrotum considerable portions of the coloured mucous body 
 in the form of a continuous independent membrane, separate 
 from the epidermis. Most generally, however, and I have 
 often tried the experiment, the maceration separates from the 
 dermis, which remains but very slightly coloured, the epider- 
 mis and corpus mucosum united and coloured; it is only with 
 great difficulty, that we can afterwards separate the mucous 
 body in the form of a membrane. If the maceration be con- 
 tinued in a small quantity of water, and the experiment be 
 made on the skin of the scrotum, a deeply coloured part, the 
 mucous body in resolving itself into a sort of mucosity, tinges 
 the water and finally deposits at the bottom of the vase, an 
 impalpable brown powder. Gautier has assigned, as the spe- 
 cial seat of the colouring matter, the middle layer of the corpus 
 mucosum, which he describes under the name of gem?nules, 
 as an undulated layer, which, with a single one of its turns, 
 would cover each one of the double furrowed lines of the der- 
 mis, of the palm of the hand, and the sole of the foot. It 
 
 * B. S. Albinus. De sede et causa coloris cefhiopum etc. homin, etc. 
 LugtL-Bat. 1737, et Annot. lib. i. cap. ii. Meckel, loc. cit. S. T. Scem- 
 mering 1 , Uelter die korperliche vcrschie.denheit des negers vom europaer. 
 
214 GENERAL ANATOMY. 
 
 would rather appear, that the pigment results from coloured 
 globules, disseminated through the corpus mucosum. 
 
 The mucous body is not only more coloured, it is also 
 thicker in the negro, than in other races, and its thickness in 
 the latter is in direct proportion to its colour; thus, it is so 
 extremely thin in the white man, that its very existence has 
 been doubted. It is still thinner and so liquid in albinos, that 
 the action of the sun easily vesicates their skins, while in the 
 negro it is with difficulty that epispastics produce that effect. 
 
 The colouring matter of the skin is very analogous to that 
 of the blood; it appears to be secreted from that humour and 
 to pass from the vessels of the surface of the dermis into the 
 mucous body, where it is in a kind of imbibition. Various mor- 
 bid phenomena induce a belief that it is continually renewed 
 there, by an unceasing deposition and absorption. Beddoes 
 and Fourcroy have observed by experiment, that the negro 
 skin plunged into water, impregnated with the vapour of 
 chlorine, becomes white, and in a few days resumes its black 
 colour in all its intensity. The chemical observations of Davy, 
 Coli and others have demonstrated that, which Blumenbach 
 had long before asserted, viz: that the pigment of the skin is 
 chiefly formed of carbon. 
 
 The use of the pigment in the coloured races, appears to be, 
 to defend the skin against the rubefacient effect of the rays of 
 the sun, commonly called a coup de soleil.* 
 
 304. The epidermis or cuticle, epidermis, cuticiilaj is a 
 distinct, though thin layer of the skin, which forms a kind of 
 dry and defensive varnish on its surface. The free or super- 
 ficial surface of this membrane, which is also that of the skin, 
 
 * See Philosoph. Transact, ann. 1821, I. On the black rete mucosum, &c. 
 by Sir Ed. Home. 
 
 f H. Fabricio, de totius animalis integumentis, ac primo de cuticula, et Vs 
 quae supra cuticulam sunt, in oper omn. Ludwig de cuticuld. Lipsiz, 1739. 
 Meckel, he. cit et Nouvelles observations sur les rtpiderme. Mem. de 1'acad. 
 roy. des sc. de Berlin, ann. 1757. Monro, sen. de cuticuld humana, oratio, 
 in works. Edinb. 1781. J. Th. Klinkosch et Hermann, de vera naturae cu- 
 ticula ejusque regeneratime. Prag-ac, 1775. B. Mojon, Sulf epidermide, etc, 
 Genao, 1815. 
 
OF THE SKIN IN GENERAL. 
 
 presents, as \ve have already seen [292], little wrinkles and 
 eminences variously arranged, and very visible to the naked 
 eye. Moreover, if we examine this surface with a magnify- 
 ing instrument, and even with a simple lens, the parts of the 
 epidermis between the little wrinkles, and which to the.naked 
 eye seem united, then appears very unequal, rugous, and pre- 
 sent little depressions, which bear the greater resemblance to 
 pores, because we see the sweat oozing from them. 
 
 The deep face of the epidermis is adherent, and can not be 
 separated from the rest of the skin by dissection, but putre- 
 faction, maceration, the action of dry and humid heat, epis- 
 pastics, and various diseases, produce this separation. When 
 it is caused by incipient putrefaction, a process preferable to 
 all others, by cautiously raising the epidermis, we perceive a 
 multitude of very fine, transparent, colourless filaments, which 
 break after being extended to a certain degree. These fila- 
 ments, well described and represented by W. Hunter, who 
 considered them as the vessels of the sweat, had been previ- 
 ously noticed by Kaau, who was of a similar opinion. Bichat 
 and M. Chaussier, also, believed them to be exhalent and 
 absorbing vessels. But we have not yet been able to inject 
 them, and inflammation, which renders the skin so vascular, 
 does not, sensibly, colour them. Cruikshank, on the other 
 hand, thinks they are not vessels, but excessively fine pro- 
 longations of the epidermis, which line the smallest pores of 
 the dermis. Seiler seems to adopt this hypothesis, and accord- 
 ing to him, they are rudiments of sebaceous follicles and 
 bulbs of hairs. It is not certain, however, that these pro- 
 longations exist when the epidermis adheres to the dermis, 
 and we may consider them as mucous threads formed by the 
 intermediate substance of the dermis, and epidermis rendered 
 fluid and viscid by incipient decomposition. 
 
 The epidermis penetrates, as it becomes attenuated, into 
 the sebaceous follicles. It penetrates, in like manner, into the 
 openings of the bulbs of the hairs. 
 
 305. It has been said that the epidermis was composed of 
 imbricated scales; but this is a deceitful appearance, it is a flat 
 
 and continuous membrane. Nunberger admits that it is fur- 
 29 
 
216 GENERAL ANATOMY. 
 
 nished with vessels, and that it is nourished by intus-suseep- 
 tion. Mojon, like Klinkosch, supposes it to contain fibres, 
 lamina, vessels, and all the properties of organization, and of 
 life. Mascagni considers it as being entirely formed of ab- 
 sorbent vessels. Fontana had previously thought he saw spiral 
 vessels in it, but M. de Humboldt found these supposed ves- 
 sels were nothing more than folds. The most attentive ex- 
 amination, and the most delicate anatomical operations, can 
 only show in the epidermis, one homogeneous layer, whose 
 adhering surface becomes insensibly confounded with the mu- 
 cous body, and which is deprived of cellular tissue, of vessels, 
 and of nerves. 
 
 306. The thickness of the epidermis is but trifling, being 
 scarcely equal to the fifth or sixth part of that of the skin. It 
 is thicker in the palm of the hand, and the sole of the foot, than 
 any where else. In these places, particularly in mechanics, 
 or in persons who walk much, it appears to be formed of seve- 
 ral layers. M. Heusinger,* considers this part as a variety of 
 the horny tissue, and has described it under the name of the 
 callous tissue. The epidermis is not so elastic as the corium, 
 is very flexible and easily torn. It is transparent, and of a light 
 grayish colour. In the coloured races it partakes of the colour 
 of the skin, but it is not so deep as the corpus mucosum. The 
 transparency of the epidermis is not every where the same; 
 if we look at it against the light, we perceive points more 
 transparent than others, previously taken for pores. 
 
 307. It is known that Leuwenhoeck thought he had per- 
 ceived them, and that he has figured them. Many have ad- 
 mitted them from this, or from physiological considerations. 
 But neither the observations of M. de Humboldt, made with 
 magnifying instruments greatly superior to those of Leuwen- 
 hoeck, nor those of Seiler, made upon the epidermis detached 
 by a razor, from the body of an animal while sweating, nor 
 my own, made by charging a piece of epidermis with a column 
 of mercury of about the weight of one atmosphere, have been 
 able to discover these pores. Again, observation teaches us 
 
 * System der Mstobgia, von Heusinger Eisenach, 1822, 4to, 
 
OF THE SKIN IN GENERAL. 217 
 
 that the epidermis prevents, or greatly moderates evaporation 
 in the dead body, and that those places which are deprived of 
 it, as well as the subjacent parts, become dry with great ra- 
 pidity. The epidermis, however, permits those matters to pass 
 which the skin absorbs during life, and certainly those it ex- 
 cretes. But what is more astonishing, is, that in the observa- 
 tions of which we have just spoken, no one has been able to 
 perceive even the openings of the epidermis, through which 
 the hairs pass, those which correspond to the sebaceous folli- 
 cles, nor even those which had been made in it with a fine 
 needle. The same thing, it is well known, happens in caout- 
 chouc. Filtering paper presents no visible pores to the mi- 
 croscope while it is wet, but when dry they are very per- 
 ceptible. 
 
 308. It being impossible then, for cutaneous absorption 
 and perspiration, to depend on the physical properties of the 
 epidermis, an explanation has been sought for in its chemical 
 properties. The dried epidermis diminishes in volume, be- 
 comes firmer, more elastic, and slightly yellowish. Macerated 
 in cold water, on the contrary, it swells a little, becomes soft, 
 less elastic, whiter and more opaque. It imbibes this fluid, 
 however, very slowly, and it requires along submersion of the 
 hands and feet in water, for the epidermis to absorb a suffi- 
 ciency of the liquid, to become white and opaque, and yet the 
 epidermis of these regions appears to imbibe it more readily 
 than that of the other parts of the body. It is to this difficulty 
 of the permeability in the epidermis, that we are to attribute 
 the difficulty with which the fluid of ampullae escapes during 
 life, and the slowness with which the skin of dead bodies dry 
 even in the most arid atmosphere, provided the epidermis re- 
 mains entire. It resists putrefaction for a long time; it has 
 been found entire in tombs at the expiration of more than fifty 
 years. Boiling water renders the epidermis white, opaque, 
 and deprives it of its elasticity much quicker than cold water. 
 Continued ebullition extracts a little gelatine from it, which 
 appears to proceed from its adhering face; the residuum does 
 not appear to differ from the entire epidermis. Exposed to 
 fire it burns like horn, and gives out a similar odour. Pure 
 
2 IS GENERAL ANATOMY. 
 
 fixed alkalies resolve it completely into a saponaceous sub- 
 stance. Nitric acid turns it yellow almost at once, thickens, 
 softens, and renders it opaque in about fifteen minutes, and in 
 twenty-four hours reduces it to a yellow pulp. If ammonia is 
 applied on the epidermis, rendered yellow by nitric acid, it 
 changes to a deep orange colour. Now Hatchett has proved 
 that similar effects took place on coagulated albumen. The 
 epidermis appears to consist of a layer of albuminous mucus, 
 coagulated and dried. 
 
 309. The epidermis is neither irritable nor sensible; of all 
 parts of the body it possesses the most active force of forma- 
 tion; it results from the concretion of a fluid exuded on the 
 surface of the skin, constantly renewed, never absorbed, but 
 destroyed externally as fast as it is produced on the internal 
 face. 
 
 310, Numerous hypotheses have been broached upon the 
 formation of the epidermis; the most ancient, is that which 
 teaches us to regard it as the drying of a fluid furnished by the 
 surface of the dermis. Others, with Leuwenhoeck, saw no- 
 thing in it but an expansion of the vessels of the skin. Others 
 again, as Ruysch, made it to consist of the expansion and dry- 
 ing of the papillae. Heister attributed its formation to these 
 two causes; Morgagni to the callification or induration of the 
 surface of the skin, from the pressure of the waters of the am- 
 nios at first, and subsequently, from that of the atmosphere; 
 and Garangeot to the induration of the rete mucosum. All 
 those opinions, particularly the first and the last, contain some 
 truth. It results, in fact, from an exudation or excretion of 
 the dermis. It is the indurated surface of the corpus muco- 
 sum; so that from the dermis to the free surface of the epider- 
 mis, there is a successive deterioration of organization, and of 
 vitality, which makes a kind of varnish of the epidermis, and 
 participating in organization and life, only by its origin, a cir- 
 cumstance which renders it very fit to support the action of 
 external bodies, and to protect the vessels, nerves, and other 
 parts of the skin. 
 
 311. The skin, formed by the dermis, the vessels and the 
 nerves which are distributed through its thickness, and par- 
 
OF THE SKIN IN GENERAL. 219 
 
 ticularly on its superficial face; by the epidermis, of which we 
 have been speaking, and by the intermediate mucous body, 
 offering, thus, a diminution of organization, and of vitality, 
 from the dermis to the epidermis, partakes of the physical, 
 chemical, and vital properties of these various parts. It is the 
 same with respect to its functions or organic actions. 
 
 312. The skin, on account of the dry and slightly permea- 
 ble epidermis, which makes a part of it, is not so well adapted 
 for absorption and secretion as the mucous membrane. 
 
 The skin being furnished with its epidermis, in a state of 
 integrity, cutaneous, or as it is also called, cuticular, absorp- 
 tion, is in fact, to this day, a subject of doubt and discussion 
 among physiologists. To decide this question between Seguin, 
 Currie, Klapp, Rousseau, Dangerfield, Chapman, Gordon, Ma- 
 gendie, &c. , whose observations and experiments go to dis- 
 prove the existence of cutaneous absorption, and Keil, Haller, 
 Percival, Home, Ouikshank, Watson, Forci, Abernethy, Bi- 
 chat, Duncan, Kelly, Bradner, Stewart, Sewall, &c., and M. 
 Young in particular, whose experiments and observations are 
 in favour of this absorption, we must abstract all those cases, 
 and they are numerous, in which absorption may have taken 
 place by respiration, as well as by the skin: those in which the 
 epidermis may have been softened, altered, or abraded by con- 
 tinued applications to its surface, or by repeated rubbings, un- 
 der which circumstances, absorption is no longer cuticular, but 
 of the same kind to that which takes place in the mucous mem- 
 brane, or by inoculation, when the matter is carried through 
 the divided epidermis into the corpus mucosum,and even into 
 the dermis, both parts being eminently absorbent. When this is 
 done, there remains a small number of facts, which show, that 
 certain substances are absorbed by the skin, through the epi- 
 dermis, in its entire state, but that this membrane is truly an 
 obstacle that very often prevents the absorbent power of the 
 external tegument. 
 
 313. The skin is also an organ of secretion and excretion. 
 Two kinds of well known extrinsic secretion take place in 
 this membrane, cutaneous perspiration and the sebaceous fol- 
 licular secretion. Perspiration is sometimes vaporous and 
 
220 GENERAL ANATOMY. 
 
 insensible, and at others liquid and visible; in the latter cat>e 11 
 is called sweat. This secretion is continual, and probably, es- 
 sentially the same in both cases; but in the first it is insensible 
 on account of its vaporisation. The secretion takes place in 
 the skin, but by what vessels, we do not know; as to the 
 ways by which it traverses the corpus mucosum and the epi- 
 dermis, we are totally ignorant. It is likely that the perspi- 
 ratory secretion takes places in the bottom of the microscopic 
 incisures and depressions of the epidermis, a place where it 
 is the least dry. The quantity of this secreted matter is very 
 great, but difficult to determine. Sanctorius, whose experi- 
 ments are so celebrated, had observed, that he lost five-eighths 
 of the whole of his aliment by pulmonary and cutaneous per- 
 spiration. Among those who have repeated his experiments, 
 Lavoisier and M. S6guin have made this distinction; they 
 found that the cutaneous perspiration, is to the pulmonary 
 perspiration on an average, as eleven is to seven. Cruikshank 
 has tried to determine its nature, and found that it had all the 
 properties of water, containing carbonic acid and an odorous 
 animal matter. 
 
 When the matter of perspiration is collected in the form of 
 sweat, we see it appear on the surface of the skin in small 
 drops, upon which Leuwenhoeck has made some interesting 
 observations. Human sweat in a state of health is always 
 acid, saltish, and odorous. According to Theuard it is formed 
 of much water, a small quantity of acetic acid, of hydro chlo- 
 rate of soda, and perhaps of potash, very little earthy phos- 
 phate, an atom of the oxide of iron, and of an inappreciable 
 quantity of animal matter. M. Berzelius considers it as water 
 holding in solution the hydro chlorates of potash and soda, 
 lactic acid, lactate of soda, and a little animal matter. 
 
 The cutaneous perspiration, either sensible or insensible, 
 must be regarded as one of the most important excretions of 
 the organism. It is, besides, a potent mean of refrigeration 
 and of resistance against too elevated a temperature. This 
 function presents numerous varieties, according to the age, 
 sex, the individual, external circumstances, the state of the 
 other functions, the action of ingested or applied substances, 
 
OP THE SKIN IN GENERAL. 221 
 
 diseases, &c. It exercises great influence over the other func- 
 tions. 
 
 314. It is admitted that gaseous secretions and absorptions, 
 analogous to those of the lungs, and constituting a sort of cu- 
 taneous respiration, take place through the skin. Thus, Spal- 
 lanzani in the mollusca, Edwards in reptiles, and Jurine even 
 in man, have seen the skin absorb oxygen. According to 
 various natural philosophers and physiologists, gases are also 
 excreted from the skin; but objections and experiments can 
 be opposed to these assertions; the experiments of Priestly 
 may also be opposed to those of Cruikshank, of Dr. McKenzie 
 and of M. Ellis, which seem to favour the theory of a cutane- 
 ous excretion of carbone, which combines with the oxygen of 
 the atmosphere to form carbonic acid. It is at any rate cer- 
 tain, that if in man, whose epidermis is dry, and whose pul- 
 monary respiration is very great, the air exercises a vivifying 
 action upon the blood which circulates in the skin, this action 
 can in nowise supply that of the lungs. 
 
 315. The skin excretes an oily matter,* that Cruikshank 
 succeeded in obtaining, in the form of black tears, on the sur- 
 face of a knitted woollen waistcoat that he wore night and 
 day for a month in the heat of summer. Rubbed on paper, 
 this matter acts like fat, it burns with a white flame and leaves 
 a carbonaceous residuum. It is uncertain whether this oil, 
 which has been said to be subcutaneous fat transuding through 
 the skin, is produced by the same channels as the preceding, 
 or the following. 
 
 316. The cutaneous follicles secrete a sebaceous matter. 
 This matter is thick, not glutinous, without any fibrous ap- 
 pearance when indurated ; by suspension in water, by tritura- 
 tion, it forms a sort of emulsion, but it does not dissolve. 
 Exposed to fire, it does not melt; it burns, leaving much char- 
 coal. It chiefly contains cerumen, a proportion of oil, that 
 may be separated from it by blotting paper. This matter is 
 formed in the sebaceous follicles, whence by pressure it may 
 be forced out in the form of little worms, and whence it na- 
 
 * Ludwig and Grutzmacher, de Humore cutem inungente. Lipsiac, 1748, 
 
222 GENERAL ANATOMY. 
 
 \ 
 
 turally oozes, to anoint the neighbouring skin, and principally 
 to defend it from the action of water and excrementitious hu- 
 mours. 
 
 It is these three matters united which constitute the cutane- 
 ous excretion, an excretion that is very abundant, a part oi' 
 which is continually evaporated, while the more fixed portions 
 cover the skin, from which they are subsequently detached 
 in the form of dirt. To these excretions must be added that 
 of the epidermis, which is continually wearing away on its 
 superficial face, and is as regularly reproduced on the opposite 
 one. 
 
 317. The skin is an organ of sensation. It is still more 
 than the other tegumentary membrane, the organ of tact, ge- 
 neral and passive, which makes us sensible of the presence of 
 bodies, their temperature, &c.; moreover, and particularly in 
 certain places, being provided with many vessels and nerves, 
 and well fitted for adaptation to the forms of bodies, it is a 
 special and active organ of touch. The tact and touch are so 
 much the more delicate, as the papillse are more developed 
 and less covered. 
 
 318. Finally, the skin is a defensive organ, not very effi- 
 cient in man, but greatly so in particular animals, where the 
 mucous body is the seat of horny and calcareous incrustations. 
 It is evident that this organ, whose functions are as multiplied 
 as its texture is complex, can not have one of its parts or one 
 of its functions greatly developed, but at the expense of the 
 others; consequently the thicker and more protecting the 
 corpus mucosum and epidermis, the duller is the .sense of 
 touch. 
 
 319. The embryo, until the middle of the second month, 
 has no distinct skin. About this period, according to Auten- 
 rieth, the epidermis begins to appear. Until half the term of 
 gestation, the skin remains thin, colourless and transparent: 
 it then assumes a rosy hue until about the eighth month ; at 
 this epoch it becomes pale, except in the folds. In about four 
 months and a half, the sebaceous follicles begin to be visible, 
 on the head first, and subsequently in the other parts of the 
 body : at seven months, the sebaceous or caseiform covering 
 
OF THE SKIN IN GENERAL. 223 
 
 / 
 
 of the skin, begins to show itself: at birth the skin is covered 
 with it, and is of a rosy white; after birth, the skin soon ac- 
 quires the colour peculiar to the race and increases in thick- 
 ness and strength until the adult age; in old age it becomes 
 dry, wrinkled, and gradually loses its colour. 
 
 The skin is thinner, finer and softer in females; but these 
 characters sometimes disappear after the age of puberty. 
 
 320. The differences presented by the skin in the various 
 races, have been already noticed [112, 116.] Individuals of 
 the coloured races and even negroes are born with nearly 
 the same colour as whites. The colour begins to show it- 
 self from the moment the child breathes, but particularly, 
 about the third day after birth, round the nails, nipples, eyes, 
 anus, and the organs of copulation; by the seventh day the co- 
 louring is everywhere extended, the palm of the hand and 
 sole of the foot excepted, which remain whitish. The colour 
 is not intense during the first year, it afterwards augments, 
 and continues for the greater portion of life to diminish in old 
 age. The odour of the skin, like its colour, varies in the races. 
 Independently of national varieties, they are many among in- 
 dividuals. 
 
 321. The morbid alterations of the skin are extremely 
 numerous. We have already spoken of cicatrices or of acci- 
 dental reproductions of this membrane [258.] The new tis- 
 sue is analogous to the old one, but is not the same. The der- 
 mis is more dense, less areolar, more compact, less vascular, 
 and less papillary than that of the skin. The epidermis evi- 
 dently exists on it, though quite recently this has been denied; 
 it is an error. The corpus mucosum exists there also, as well 
 as its coloured layer; and Camper is wrong when he asserts, 
 that the cicatrices of the negro are white; the hue is merely a 
 little different. Horny productions sometimes form upon the 
 cicatrices; these accidental teguments are very liable to ul- 
 cerate. 
 
 Accidental skin is sometimes found in the cysts of the ova- 
 ries, it is probably an imperfect production of a foetus, either 
 engendered, or enveloped in the foetal state, by the individual 
 which contains them. 
 30 
 
224 GENERAL ANATOMY. 
 
 322. The skin sometimes presents primitive vices of con- 
 formation, either by deficiency, which causes divisions or de- 
 nudations in the foetus, or by excess, which forms folds or sacs 
 more or less extensive. It presents also acquired vices of con- 
 formation; its distention, carried to a great degree, as for in- 
 stance in pregnancy, separates, loosens the fibres of the dermis, 
 and produces welts, after delivery, which at first are brown or 
 blackish, that afterwards become and remain more white and 
 shining than the rest of the skin. A more moderate and more 
 continued degree of distention, produces a loss of its elasticity 
 and retractility, and when it is removed leaves wrinkles more 
 or less deep. 
 
 323. The skin is the frequent seat of congestions, dis- 
 charges, and inflammations, acute and chronic, whose various 
 effects, either on the texture of the membrane, on its colour, or 
 on the products of its secretion, have given rise to the esta- 
 blishment of fifty genera, and more than a hundred species of 
 cutaneous diseases, consisting of pimples, scales, eruptions, 
 ampullae, pustules, vesicles, tubercles, spots, &c., respecting 
 which the works of Plenck, Alibert, Willan, and Bateman, 
 may be consulted with advantage. 
 
 324. The retention of the sebaceous matter, and its accu- 
 mulation in the follicles, give rise to the formation of tumours 
 called pimples, when they are small, and which, when large, 
 are confounded with the encysted tumours under the names 
 of wens, meliceris, steatomatous tumours, and atheromse. 
 When the tumour is small, and the orifice of the follicle is not 
 obliterated, the sebaceous matter may be forced out of it by 
 pressure in the form of a worm, a circumstance, which has led 
 some inattentive observers, who are fond of the marvellous, 
 into error. When, on the contrary, the tumour has greatly in- 
 creased, and grown voluminous under the skin, and its orifice 
 is not apparent, it greatly resembles a cyst; but by dissecting 
 it with care, traces of the orifice may be found in the point 
 where it holds to the skin; and if we split the skin and the tu- 
 mour in that point, we can easily follow the epidermis, which 
 is reflected from the surface of the first into the cavity of the 
 second. Whether the matter contained in it, resemble honey, 
 
OF THE SKIN IN GENERAL. 225 
 
 bouilli, or tallow, it is always sufficiently like the matter of 
 the sebaceous follicles, to be recognised. 
 
 325. Various accidental productions, either analogous or 
 morbid, are observed in the skin. This membrane is some- 
 times raised up by a more or less great, and sometimes, an in- 
 numerable quantity of tumours, very various as to size, and 
 formed by the accidental production of a white fibrous tissue, 
 that is much more compact than the cellular tissue, and looser 
 than the ligamentous tissue, one that is often found in polypi, and 
 particularly in the sub-mucous tumours of the vagina and vulva. 
 326. The colour of the skin presents various changes. That 
 of the albinoes is the most singular: their skin is of a dead, or 
 rosy white, very different from the white of Europeans; their 
 hairs are transparent, whitish, or rather colourless; the iris of 
 the eye is of a pale rose, and the opening of the pupil red, 
 which is owing to the absence of the pigment of the choroides, 
 and of the uvea. The functions of the skin, and particularly 
 of the eyes, feel the effects of this alteration, which has been 
 attributed to the absence of the mucous body, and which, at 
 any rate, certainly depends upon that of the colouring matter 
 of the skin and its appendages; it is wrong to regard it as the 
 effect of a leprosy, a cachexia, or as a state of -disease; it is an 
 error of Blumenbach and Winterbottom, sufficiently refuted by 
 the observations of Jefferson, who expressly declares, that all 
 the individuals of this kind that he saw were well made, strong 
 and healthy. This alteration is found in all the races of the 
 human family, in every part of the globe, and in a great many 
 genera of animals. It begins at birth, continues through life, 
 and is transmitted by generation. The union of an albino and 
 of a coloured person, generally produces coloured offspring, 
 and sometimes albinoes. It does not, however, constitute a 
 race in the human species, but is found sporadically, or as ac- 
 cidental varieties. 
 
 The noevi and marks on the skin, consist, in some cases, of a 
 coloured patch of the mucous body, which in this case is 
 usually visibly thicker in that point than elsewhere; in others, 
 they consist in an erectile disposition of the cutaneous vessels, 
 which will be described hereafter. (Chap. iv. ) 
 
226 GENERAL ANATOMY. 
 
 The colour of the skin is also subject to accidental altera- 
 tions: thus we see individuals among the whites become brown, 
 or perfectly black, in places of more or less extent. Whites 
 and blacks also become albinoes in points of the skin more or 
 less extensive. 
 
 May not the melanosis which usually coincides with the dis- 
 colouration of the skin, and which is so often observed in white 
 hairs, depend upon an aberration of the pigment of the skin? 
 
 Horny productions, which project more or less from the 
 surface of the skin, are sometimes found in the corpus muco- 
 sum; these productions being analogous to the nails, will be 
 described after these appendages of the skin. 
 
 ARTICLE II. 
 OF THE APPENDAGES OF THE 
 
 327. The nails and hairs are the only appendages of the 
 human skin; in animals, on the contrary, they exist in great 
 numoers and variety. It is an error to consider these parts as 
 appendages of the epidermis alone, for they are connected with 
 the whole skin. 
 
 1. OF THE NAILS.* 
 
 328. The nails, ungues, are horny scales which cover the 
 skin of the last phalanx of the fingers and toes, on the side of 
 the extensors. 
 
 Three parts are noticed in the nail, viz: the root, the body, 
 and the free extremity. 
 
 The root or adhering extremity, is the fifth or sixth part of 
 the length of the nail; it is the thinnest part of it; it is received 
 nto a groove in the skin, and is of a white colour. The body, 
 
 * Frankeneau, de Unguibus. Jenoe, 1796. Ludvvig, de ortu et structure! 
 unguium. Lipsiae, 1748. B. S. Albinus, in Arinot. acad. lib. ii. cap. xiv. 
 de Ungue humano, ejusque reticulo &?c., et cap. xv. de Natura unguis. Bose, 
 de Unguifas humanit. Lips. 1773. Haase, de Nutritione unguium. Lips. 
 1774. 
 
OP THE NAILS. 227 
 
 or middle part, is of a middling thickness; its external free 
 face is smooth, presents longitudinal furrows, more or less 
 deep, and is transversely convex. Its opposite face adheres 
 closely to the skin; the posterior part of the body of the nail, 
 for a small extent and which gradually diminishes in proceed- 
 ing from the thumb to the fourth or little finger, is white; 
 this semi-lunar portion has been called the lunula; the other 
 part appears reddish on account of its transparency, which 
 renders visible the colour of the skin. The free extremity of 
 the nail is its thickest part; it projects beyond the end of the 
 finger and shows a tendency, although but slight, to curve into 
 a sort of hook. 
 
 329. The connexion of the nail with the dermis and epi- 
 dermis is effected in the following manner: the dermis is thick- 
 ened and very papillar beneath the body of the nail, under the 
 lunule excepted; the papillae are arranged in linear series 
 like very delicate and closely approximated longitudinal sulci. 
 The corresponding face of the nail is soft, pulpy and furnished 
 with longitudinal grooves, which receive and adhere very 
 closely to the papillary furrows of the dermis. Their separa- 
 tion, however, in the dead body, is produced by the same 
 causes that separate the epidermis and mucous body from the 
 dermis. The adhering extremity of the nail, very thin and very 
 soft, is received into the bottom of a fold of the dermis, de- 
 prived of epidermis. Under the small and irregularly deve- 
 loped nails of the last toes, the papillae of the dermis are ar- 
 ranged irregularly and not in linear series; the adhering face 
 of the nail presents the same irregular disposition for the re- 
 ception of the papillae. 
 
 330. The epidermis having arrived near the root of the 
 nail, is reflected with the dermis to the bottom of the furrow. 
 There the dermis passes under the nail; the epidermis on the 
 contrary is reflected over its root, and is prolonged over its 
 external face, which it thus covers with a very thin lamina, 
 that is confounded with it. At the free extremity of the nail 
 the epidermis of the end of the finger is reflected under its 
 deep face and is united to the free part of that face. On the 
 
228 GENERAL ANATOMY. 
 
 sides there is, behind, a disposition analogous to that at the 
 root, and before, to that of its free extremity. 
 
 The nails have no connections besides those just described. 
 It is from want of observation that some anatomists have 
 admitted them to have others with the periosteum and the 
 tendons. 
 
 331. Some have admitted, with Blaucardi, that the nails 
 are formed of agglutinated hairs; others, that they result from 
 the super-position of scales or horny lamina, the uppermost 
 of which is the whole length of the nail, while the others suc- 
 cessively diminish in length, which occasions a regularlj 
 increasing thickness from the root to the free extremity. 
 These are rather ways of accounting for the mode of the forma- 
 tion of the nails, than results of observation, which in fact dis- 
 covers in the nails a horny substance only, hard and dry ex- 
 ternally, and mucous in the interior. Neither vessels nor 
 nerves are to be found in them. They consist in a thick and 
 horny layer of the mucous body of the skin. 
 
 332. The nails are diaphanous, flexible, and elastic; they 
 may be torn crosswise, notwithstanding their fibrous appear- 
 ance in another direction. Their chemical properties are those 
 of coagulated albumen; they appear also to contain a little 
 phosphate of lime; they are very similar to horn. They are 
 totally deprived of irritability and sensibility. The force of 
 formation or a continual growth by a sort of vegetation, is the 
 only organic and vital phenomenon observed in them; even 
 this is foreign to them. The materials of which they are 
 formed, are continually and proportionably secreted and ex- 
 creted by the dermis: this matter applied to the extremity 
 and adhering face of the nail, like that of the secretion of the 
 silk-worm, concreting as fast as it is excreted, and being con- 
 tinually added to that which has preceded it, pushes it before 
 it, and thus lengthens the nail by juxta-position, and not by 
 intus-susception. It is then a true excretion, whose materials, 
 once deposited, are never absorbed. The nails arm, support 
 and protect the extremity of the fingers and toes. 
 
 333. The nails begin to appear about the middle of the 
 foetal, term: even at birth they are still very imperfect. In 
 
OF THE NAILS. 229 
 
 the coloured races, the colour is subjacent to the nail. In 
 many animals, on the contrary, the coloured layer of the mu- 
 cous body is confounded with the horny layer in the compo- 
 sition of the nails and similar parts. The parts most analo- 
 gous to the nails of man are the claws of the carnivora, &c., 
 which surround the dorsal face and the sides of the last pha- 
 lanx, and are curved towards the sole; and the hoofs of the 
 ruminantia, &c., which envelop the whole extremity of the 
 last phalanx. The nails of the human foot have sometimes a 
 considerable growth, and assume a direction that approximates 
 them to claws. 
 
 334. The alterations* attributed to the nails, are, in fact, 
 utterly foreign to them, and depend wholly on the skin that 
 produces them. It is the same with respect to accidental 
 horny productions: it is in the subjacent tissue, that we must 
 seek for their origin. 
 
 When a nail has been torn by violence, or detached by dis- 
 ease from the subjacent skin, it grows again slowly, and differs 
 more or less from the primitive one, just as the affection of 
 the skin continues more or less, at the time of its second 
 growth. 
 
 Horny laminae, more or less analogous to the nails, are 
 formed upon cicatrices, the ends of the toes and other places 
 exposed to pressure or violent and reiterated friction, such 
 are callosities, &c. Simple ichthyosis, differs from them only 
 in its extent and our ignorance of its cause. 
 
 Corns also consist of round, hard, small, accidental horny, 
 productions, which by the compression they transmit, irritate, 
 inflame and sometimes pierce the skin, and even affect the 
 bones and subjacent articulations. 
 
 Horns or horny conoid productions more or less elongated, 
 have been very often observed from the earliest ages on al- 
 most all parts of the skin. Sometimes a single one of these 
 excrescences exist on an individual and is developed on a ci- 
 catrix, in a sebaceous follicle, or on some point of the skin, 
 that has been previously altered, or even without any thing 
 
 * Plenck, de marbis unguium, in dodrind de rnorbis cutancis. 
 
230 GENERAL ANATOMY. 
 
 particular in the skin having been marked; at others, produc- 
 tions of this kind exist on almost every part of the skin, con- 
 stituting a species of ichthyosis. 
 
 The warts of the skin and those of the mucous membrane, 
 may be approximated to the accidental horny productions, and 
 be considered as an imperfect horny tissue, both of them par- 
 ticipating in the horny tissue, and in that of the membrane. 
 
 In certain general as well as local affections of the skin, as 
 well as the habitual contact of acids, &c. as happens in some 
 professions, the nails soften, become fleshy, and imperfect 
 horny tissue, vegetate irregularly, present excrescences, be- 
 come dry, and fragile. They always partake of the healthy 
 or diseased state of the skin of which they are a production. 
 Inverted toe nail is merely the mechanical cause of an inflam- 
 mation of the skin. 
 
 II. OF THE HAIRS.* 
 
 335. Hairs, pili 9 crines, are horny filaments, generally 
 fine and long, which in a greater or less number cover almost 
 all parts of the skin, except the palm of the hand and the sole 
 of the foot. 
 
 Each hair consists of a bulb and stem, and the texture of 
 each of these parts is tolerably complex, particularly distin- 
 guishable in their most voluminous points. 
 
 336. The bulb or follicle of a hair, which Malpighi com- 
 pared to the vases in which gardeners plant vegetables, and 
 which has been ably described by Chirac, is situated in the 
 thickness of the dermis or under it; it is of an ovoid form; by 
 one of its extremities, which penetrates obliquely through the 
 skin, it communicates with the surface of that membrane; and 
 
 * P. Chirac, Leitre tcriie a M. Regis sur la structure des cheveux. Mont- 
 pellier, 1688. M. Malpig-hi, de Pills, ols. in op. posth. WithofF, JLnatome. 
 pili humani. Duisb. 1750 et in Comm. soc. sclent. Getting 1 . 1753. ,T. H. 
 Kniphof de pibrum usu. Erf. 1754. Duverney, (Euvres anatom. Paris, 
 1761. Albinus, Acad, annot. lib. iv. chap. ix. T. P. PfafF, de variet. pilor. 
 natural et prseternat. Halae, 1796. Car. Asm. Rudolphi, Diss. depilorum 
 structura, Gryphiswald, 1806. Gautier, L. c. Heusinger, L, c. &c. 
 
OP THE HAIRS. 231 
 
 by the other, which is deep and furnished with implanted fila- 
 ments like roots, it is plunged into the sub-cutaneous cellular 
 tissue. Externally, it is. formed by a capsular, firm, coria- 
 cious, white membrane, which is continuous with the dermis 
 by its superficial extremity. Inside this membrane is another, 
 thinner, soft, reddish, or variously coloured, and which appears 
 to be a continuation of the mucous body. The cavity of this 
 membranous follicle is filled in a great measure by a bulb or 
 conical papilla, adhering by its base to the bottom of the cavi- 
 ty and free at its summit, which rises towards the orifice of 
 the follicle. 
 
 Blood vessels reach the papillae, according to Gautier, by 
 the mouth of the bulb, creeping between these two membran- 
 ous layers, and according to my own observations, by the bot- 
 tom. By dissection I have also followed nervous threads even 
 into the root of the follicle, which I consequently consider as 
 being formed by vessels, nerves and cellular tissue. 
 
 The bulbs of the hairs, then, seem to consist in a little piece 
 of excavated skin, depressed or doubled over, surmounted by 
 a papilla, and furnished with nerves and vessels, which, in 
 comparison with the smallness of the space where they are 
 distributed, are voluminous. 
 
 In the thickness of the neck of this piliferous bulb, we find 
 several little sebaceous follicles, circularly arranged. 
 
 237. The stem of the hair is planted by one of its extremi- 
 ties in the piliferous bulb, and is free for the rest of its extent. 
 Its form is conoid, its free extremity being a little thinner 
 than the rest. Its length is very variable, its thickness like- 
 wise. The base is hollow and lodged in the bulb where it 
 embraces the papilla; the summit is often split; whatever "be 
 the colour of the hair, its root is always white and diaphanous; 
 the portion contained within the bulb is always softer than the 
 remainder, its most inferior portion, that which covers the 
 papillae, is perfectly fluid. It has been said, that the surface 
 of the hair was scaly, or covered with microscopic asperities, 
 free near the summit, and adherent at the root; I have never 
 been able to see them. 
 
 338. The connexion of the hair with the skin is effected 
 31 
 
 
232 GENERAL ANAT6MY. 
 
 as follows: it is attached by its base, which is hollow, to the 
 surface of the papilla; in addition to this, the epidermis, after 
 being brought from the surface of the skin to the mouth of the 
 bulb, is reflected on the base of the hair, is united to, and con- 
 founded with its surface; the hair is thus strongly connected 
 with the skin, and can not be drawn with any force, without 
 occasioning pain; the separation of the hair in the dead body, 
 is effected by the same causes, which detach the nails and epi- 
 dermis from the skin. 
 
 339. The stem of a hair consists of a horny sheath that is 
 diaphanous, and nearly colourless, and of an internal coloured 
 substance, generally described as consisting of a certain num- 
 ber of filaments, said to be from five to ten, moistened with a 
 colouring matter; some have asserted this sheath is filled with 
 a spongy substance similar to that found in the stems of fea- 
 thers; others have pretended that the internal filaments are 
 vascular; it has also been affirmed that a hair consists of one, 
 single, homogeneous, horny filament, which is not probable; 
 Mascagni states it to be entirely formed of absorbent vessels. 
 It appears, on the contrary, that the hairs, like the epidermis 
 and horn, are totally deprived of vessels and nerves; that they 
 simply consist in a prolongation of the two layers of the cor- 
 pus mucosum, the horny layer, and the coloured layer, to which 
 is joined the epidermis. 
 
 340. The colour of the hairs generally, corresponds to that 
 of the skin and eyes. In those individuals who have coloured 
 spots, or albinous spots, the hairs are coloured in the former, 
 and white or colourless in the latter. They are very strong, 
 and support considerable weight without breaking. They are 
 easily torn or split lengthwise. They are very hygroscopic, 
 moisture swells and lengthens them, dryness shortens them: 
 Saussure has profited by this phenomenon in the construction 
 of the hygrometer that bears his name. They are idio-electric. 
 They depolarize light, and according to Dr. Brewster, their 
 axes are perfectly neuter, being parallel and perpendicular to 
 the axes of the hair. 
 
 According to Mr. Hatchett, a continued ebullition of the 
 hairs, deprives them of a little gelatine, while the remaining 
 
OF THE HAIRS. 233 
 
 substance, which loses a portion of the elasticity and tenacity 
 of the hair, has all the properties of coagulated albumen. They 
 strongly resist putrefaction. Their colour changes at first, but 
 the corneous matter resists for a great length of time. Vau- 
 quelin has found that they dissolve in Papin's digester; that 
 they are dissolved by water containing four hundredths of 
 caustic potash; and that they are acted on by all the acids. 
 According to this celebrated chemist, they are composed of 
 an animal matter which forms their base, of a small quantity 
 of a white concrete oil, of a blackish oil, of iron, oxide of man- 
 ganese, phosphate of lime, carbonate of lime, silex and sul- 
 phur. 
 
 341. They are neither irritable nor sensible; their force of 
 formation or vegetative power is very active. 
 
 The motions of the hairs are communicated to them by the 
 sub-cutaneous muscles, and by the contraction of the skin itself. 
 Each of the large hairs or prickles of certain animals, are, in 
 addition, provided at the root with a little muscle destined to 
 elevate it. Although, strictly speaking, the stems of the hairs 
 are insensible, yet as their roots are placed over a papilla pro- 
 vided with a nerve, they transmit to it with great accuracy 
 the effects of contact with external bodies that act on them 
 mechanically. Their production or vegetation is continual, it 
 is analogous to that of the epidermis and the nails, and like it, 
 constitutes a true excretion. Certain facts seem to indicate, 
 that there occurs in their interior, not a true circulation, but an 
 imbibition, and that a coloured liquid slowly traverses them, 
 from the root towards the summit. They have been stated, 
 without any proof, to be organs of absorption. Their use is to 
 protect the skin, and in some places, particularly, to serve the 
 purposes of sensation. They have also local uses. 
 
 342. The hairs present considerable differences, relative 
 
 to the regions they occupy, and have received various names. 
 
 On the cranium they are called, hair, capilli, coma, ctesa* 
 
 ries: these hairs are the longest, the most numerous, strongest 
 
 and thickly set. 
 
 The brows and lashes belong to the eyes; the orifices of the 
 nostrils and ears are also furnished with hairs. 
 
234 GENERAL ANATOMY. 
 
 The cheeks, the environs of the mouth and chin are occu- 
 pied by the beard, barba,julus, mystax, pappus. 
 
 The groin is furnished with them, glandebalae, as well as 
 the yubis, pubes, the scrotum labia pudendi, and around the 
 anus. 
 
 The rest of the body, both trunk and limbs, are more or less 
 possessed of them. On the trunk they are more numerous on 
 the anterior than the dorsal face, which is precisely the re- 
 verse of what generally takes place in animals; in the limbs 
 there are fewer on the internal side than the external one. 
 The hairs of the greater part of the body and limbs are thinly 
 scattered, very fine, short, and scarcely visible; they have no 
 particular names, and are in great numbers and highly de- 
 veloped in particular hairy individuals, homines pilosi. 
 
 343. The rudiments of the hairs are perceptible on the 
 foetus about the middle period of pregnancy. They make 
 their appearance in the mucous body in form of globules simi- 
 lar to those of the pigment. On these globules arise little hol- 
 low cones, the sheaths of the hairs. They remain for some time 
 under the epidermis, and finally traverse it obliquely, through 
 pores, it has been said, but none are to be found. 
 
 At an early period, on the skin of the foetus, is found a fine 
 down, lanugOj at first colourless, that covers the whole of the 
 body, and which assumes in the different regions determinate 
 directions. These silky.hairs, are, for the most part, detached 
 about the eighth month of gestation, and are found in the water 
 of the amnios, and in the meconium. It is in the last month 
 that the eye-brows, eye-lashes, and the hair begin to appear. 
 After birth the remainder of the down falls. At the age of 
 puberty begin to appear the beard, the hairs of the nose and 
 ear, those of the axillas, the pubis, the organs of copulation, 
 the anus, and those of the rest of the body. After the adult 
 period of life, and in old age, the hairs generally become white 
 and fall. 
 
 The hairs of the head are generally longest, and most numer- 
 ous in females; they have, generally, no beard, nor hairs round 
 the anus, and those of the remainder of the body are finer and 
 more thinly scattered. After the age of fecundity the beard 
 
OF TJIE HAIRS. 235 
 
 is sometimes developed. Women in general, are less liable to 
 
 become bald than men. 
 The human races, as regards hairs, present differences that 
 
 have been already pointed out. (112 117.) 
 
 Individuals also present numerous ones; some of which re- 
 late to colour, of which there are a great variety of shades; 
 others to their thickness, number and length. Withoff found 
 that on a portion of skin one fourth of an inch square, there 
 were 147 black hairs, 162 chestnut, and 182 auburn. 
 
 Parts highly analogous to hairs, are found in some of the 
 mammalia where they constitute spines; they are horny sheaths, 
 coloured^hard, and pointed, and containing internally, a white 
 spongy substance that has but little solidity; such are the quills 
 of the porcupine. The ordinary hairs seem principally to con- 
 sist of the former substance. 
 
 344. Accidental hairs are found on various parts of the 
 skin and mucous membrane, as well as in cysts. A popular 
 error existed among the ancients respecting the heart, which 
 was said to have been covered with hair, accredited by Plu- 
 tarch and Pliny. Homer, according to some, talks of the hairy 
 heart of Achilles; but it appears that it is of the hairy breast 
 of his hero that he really speaks. As to the other facts, it 
 would appear, according to the remark of Senac, that the whole 
 matter relates to hearts bristled with accidental cellular tissue. 
 The accidental hairs of the skin are those which are found on 
 coloured spots, or on parts of the skin that are thicker than the 
 rest of that membrane; they have been known to acquire con- 
 siderable development on portions of skin previously inflamed. 
 Hairs have often been seen growing from various parts of the 
 mucous membrane ; most generally they have been found in 
 cavities lined by that membrane, or ejected either alone, or as 
 parts of concretions. Although many of these facts are well 
 authenticated, we must not forget, that hairs may be swallowed 
 or otherwise introduced. The hairs of the cysts, either cuta- 
 neous or mucous, are sometimes fixed, and at others free, and 
 in ordinary cases are mixed with fat or sebaceous matter. 
 Those that are fixed in the cysts of the ovary, are in general 
 very evidently placed on the cutaneous parts of those cysts. 
 
236 GENERAL ANATOMY. 
 
 As to those of the wens of the eye-brow, of the cranium, &c. 
 they appear to me to be nothing more than sebaceous folli- 
 cles, and the hairs they contain, than hairs of the skin, which 
 instead of being directed to the surface of that membrane 
 through the orifice of the follicle, have been turned aside by 
 the accidental enlargement of that cavity. 
 
 345. These alterations of the hairs* like those of the nails, 
 have all their origin and cause in the generating parts; the horny 
 part produced, suffers its effects. When a hair has been torn out 
 by violence or has fallen by the effect of a disease of the skin, 
 and this has ceased, it grows again and increases by the same 
 organic process as the nails. This regeneration is effected 
 in the same way as in the first production [343.] When from 
 age or other causes, the hairs begin to whiten, it is by its free 
 extremity the albinism begins; the autumnal whitening of 
 many animals takes place in a similar mode, which seems de- 
 cisively to indicate, that the interior of the hair is the seat of 
 a sort of imbibition, the matter of which is furnished by the 
 papillae of the bulb or follicle. This would also seem to be 
 indicated by the circumstance, that after severe fevers, and in 
 many chronic diseases, the hairs of the head, when they do 
 not fall, undergo a kind of diminution or atrophy; they be- 
 come transparent, dry and brittle, and when health is restored, 
 resume their original qualities. The hair of the head has also 
 been seen, after or without experiencing the change produced 
 by albinism, to change colour and become black. The mor- 
 bid phenomenon of the plica polonica, in which the hair is 
 said to become soft and fleshy, and to bleed when cut close to 
 the skin, forms no exception to the general proposition, that 
 the stem of the hair only participates in the healthy or morbid 
 state of the skin. It may, in fact, easily be conceded, that 
 the papillae of the hair, if it is inflamed, may rise, contained 
 within the root of the hair to the level of the skin, and that 
 its vascular tissue may be wounded in cutting the stem of the 
 hair, but there is not much exaggeration in what is related con- 
 cerning this affection. 
 
 * Plenck, de Morbis capillorum, in op. tit. W. Weclenmcycr, Hisioria 
 pathol. pilorum. Getting. 1812, 4to. 
 
OP THE VASCULAR SYSTEM. 237 
 
 CHAPTER IV. 
 
 OP THE VASCULAR SYSTEM. 
 
 346. The vascular system, syslema vasorum, results from 
 the union of a multitude of ramified canals, communicating 
 with each other, and in which the nutritive fluids continually 
 circulate throughout the whole body; receiving at the tegu- 
 mentary sur&ces the substances of extrinsic absorption, and 
 there yielding those of the excreting secretion; alternately 
 depositing in and taking from the close cavities of the serous 
 membranes, and the areolae of the cellular tissue, continually 
 furnishing the substance of the organs with materials of com- 
 position, and constantly conveying away those of decompo- 
 sition. 
 
 347. In the simplest animals, the whole mass of the body, 
 every way equally permeable, is directly imbibed with the 
 matters of absorption, and throws out in as simple a manner 
 those of excretion; in animals placed a little higher in the 
 scale of organization, the tegument, the essential seat of ab- 
 sorption and extrinsic secretion, is more or less ramified in 
 the mass of the body, by means of which the substances for 
 absorption are distributed, and those of excretion drawn from, 
 the diverse parts of the jnass of the body; finally in those of 
 a still higher degree, and which embraces a great part of the 
 animal kingdom, we observe vessels penetrating the mass of 
 the body and ramified in every direction, every way distri- 
 buting and taking up again the matter destined for nutrition. 
 
 348. In man, as well as in many other animals, the blood 
 contained in the vessels, is continually conveyed from a cen- 
 tral point to every part, and returned from all parts to the 
 centre, so as to describe a circle; hence to this vascular system 
 
238 GENERAL ANATOMY. 
 
 and its dependences the name of circulatory apparatus is given; 
 the second name relating to the formation, and the first to the 
 function. 
 
 This system comprehends three species of organs, two of 
 which, the arteries and the veins, contain blood ; the arteries 
 convey it to every part of the body, and the veins bring it 
 back from these parts; the arteries and veins are united at the 
 centre by means of a hollow and muscular organ, the heart. 
 The third species, the lymphatic vessels, convey, not blood, 
 but chyle and lymph, and pour them into the veins; they 
 should be considered as an appendage of the venous system. 
 
 349. The arteries and the veins are in such relation with 
 the heart and the blood, that they may be farther divided into 
 two other sections. 
 
 The blood is brought by the veins from all parts of the 
 body to the heart, and hence conveyed to the lungs by the 
 pulmonary artery; it returns from the lungs by the pulmona- 
 ry veins to the heart, hence to be conveyed by the aorta to 
 every part of the body, from which it is brought back again 
 by the venae cavae. The name of pulmonary, or small circula- 
 tion, is given to the short circuit of the blood from the heart to 
 the lungs and from the lungs to the heart, and the name of pul- 
 monary vessels to the tubes, which give rise to this circulation. 
 The name of general or great circulation is given to the course 
 of the blood from the heart to all parts of the body, and from 
 these parts to the heart, and the name of aorta and of venae 
 cavae, or of general vessels, to those that are traversed by the 
 blood in this circle. 
 
 350. The blood contained in the general veins of the body, 
 in the anterior or right side of the heart and in the pulmonary 
 artery, is of a brownish red colour; it is called venous: that 
 which is contained in the pulmonary veins, the other half of 
 the heart and the aorta and its branches, is of a vermilion or 
 arterial red. Circulation has also been divided, according to 
 the blood that it contains, into that of black blood and into 
 that of red blood. Bichat, author of this division, which had 
 been perceived by Galen (sect, ii.), has thought proper to 
 describe the first mentioned part of the circulation, under the 
 
OF THE VESSELS IN GENERAL. 239 
 
 name of vascular system with black blood, and that mentioned 
 in the second place, under the name of vascular system with 
 red blood. It is easy to perceive that this division, pregnant 
 with practical results, is entirely founded on a physiological 
 basis, and not on the resemblance of the texture of the parts. 
 
 351. The three species of vessels having a very great ana- 
 logy with each other; the two sanguineous vascular systems 
 having especially great relation with each other; and the 
 venous and lymphatic systems also greatly resembling each 
 other, we must, before describing each species, present the ge- 
 neral considerations just alluded to, those which relate to the 
 vessels generally, as well as those which refer to their termi- 
 nations. 
 
 SECTION I. 
 
 ARTICLE I. 
 OF THE VESSELS IN GENERAL. 
 
 352. The situation of the vessels is interior or deep seated. 
 The largest are generally placed towards the centre of the 
 body, and at the surface very small ones only are found, and 
 even in this case, they are separated from external bodies by 
 a layer of substance which is not vascular. 
 
 The principal vessels, either in the trunk or in the limbs, 
 are generally placed in the same directions as that of the 
 flexion of the parts. We generally find together an artery, 
 one or two veins, and several lymphatic vessels: besides, we 
 meet with many lymphatic vessels and veins under the skin, 
 and but few arteries. 
 
 353. The respective volume of the three kinds of vessels 
 is such, generally, that the vessels which return the fluids, 
 that is to say, the veins and lymphatics, are, taken as a whole, 
 much more voluminous than the arteries. The veins alone 
 
 are generally much more capacious than the arteries to which 
 32 
 
240 GENERAL ANATOMY. 
 
 they correspond; this holds good, particularly with respect 
 to the larger vessels of the body. As to the relation of volume 
 and number, or of the total capacity between the venous and 
 lymphatic vessels, it is less known; it is very well known, 
 however, that under the skin, the mucous membranes, and 
 around the sefous membranes, there are a great many veins and 
 lymphatic vessels; that in the muscular interstices of the limbs, 
 and of the parietes of the trunk, there are also numerous lym- 
 phatic vessels with the veins, while in the spinal canal, and 
 within the cranium there exists a great many voluminous 
 veins, and few or perhaps no lymphatic vessels. Do these re- 
 lations depend on the difference of the matter with which the 
 muscles and the nervous substance are nourished, and conse- 
 quently on the different matter which remains in the circula- 
 tion? 
 
 354. The external form of the vascular system is that of a 
 tree, the trunk of which is attached to the heart, and which is 
 successively divided into branches, and ramusculi which be- 
 come smaller and smaller branches. Each part, from its origin 
 in a larger branch to its division in smaller ones, generally 
 preserves a cylindrical form. Each branch being smaller than 
 the one from which it proceeds, and larger than each of the 
 ramusculi arising from it, the result is a successive diminu- 
 tion from the trunk to the end of each of these last ramifica- 
 tions. Since, generally speaking, the sum of the branches re- 
 sulting from the division of a trunk, is greater than the volume 
 of the trunk itself, it follows, that the vascular system has the 
 form of a cone whose summit is at the heart, and whose base 
 is formed by the union of all the branches ramified in the body. 
 
 355. The number of the divisions of the vascular system, 
 from its centre or origin, to its last sub-divisions, is not the 
 same in all its parts. It has been very much exaggerated in 
 computing it at forty; Haller was nearer to the truth, in consi- 
 dering the maximum of the successive divisions of a vessel 
 from its trunk to its last ramifications to be about twenty. 
 
 In certain places vessels are divided, and form a bifurcation 
 in such a manner, that the trunk terminates by its division into 
 two branches, and the branch, by its separation, into two small 
 
OF THE VESSELS IN GENERAL. 241 
 
 twigs. Thus the aorta bifurcates and forms the primitive iliacs, 
 these latter bifurcate also in their turn; the primitive carotids 
 are also divided into two smaller branches. The intestinal 
 vessels present this dichotomic division in a remarkable man- 
 ner. 
 
 The angles that the vessels form in dividing, and at which 
 the branches are separated from the main trunks, vary, but 
 the greater number are acute towards their smaller branches. 
 We should observe with Haller, that these angles, to which 
 much importance was formerly attached, are mostly destroyed 
 or changed by dissection, and by removing the cellular tissue 
 which surrounds the vessels. Some of the angles are nearly 
 right angles; these are generally the first and the largest divi- 
 sions of the trunks: for instance, the branches of the curvature 
 of the aorta, the coeliac, the renal arteries, &c. ; the renal and 
 hepatic veins, the sub-clavian veins, the jugulars, &c.; the 
 thoracic duct at its entrance into the left sub-clavian vein, and 
 some others, such as the median artery (sacra media) &c. 
 Some vessels form even obtuse angles, such are the first inter- 
 costal vessels, the inferior vessels of the cerebellum, those of 
 the heart,* and some vessels of the limbs, &c. The greater 
 number finally form acute angles, and often very acute, such 
 are, for instance, the spermatic vessels. 
 
 We must observe with respect to the angles, which are con- 
 sidered as being right angles, and even-obtuse, that the greater 
 number are really acute; but at a small distance from the ori- 
 gin, the branches after a little distance change their direction, 
 bending their course in contrary direction from that of the 
 trunk, resembling very much the bent of the limbs of the 
 weeping willow. 
 
 No law or general rule can be deduced from the observation 
 of the angles formed by the divisions of the vessels. Thus 
 we observe the bifurcations or divisions, and sub-divisions of 
 the vessels of every size, to form angles more or less acute. 
 
 What is true of the large vessels, is equally so of the smallest, 
 
 * The coronary vessels might, with propriety, have been enumerated first 
 among those which form an obtuse angle, with the main trunk from which 
 they arise. TBANS. 
 
242 GENERAL ANATOMY. 
 
 in the divisions of which we, in like manner, generally find 
 acute angles, some right angles, and even some obtuse ones. 
 
 356. The branches of the different parts of the vascular 
 system, at the same times that they divide or ramify, in pro- 
 portion as they are removed from the centre of the system, 
 nevertheless conimunicate or anastomose with each other. The 
 lymphatic vessels are those which have the greatest number of 
 these communications; in the veins there are a great many, in 
 the arteries there are fewer, and nevertheless they possess a 
 considerable number. These anastomoses occur by the union 
 of two vessels of the same kind, and of an equal volume or 
 calibre. 
 
 In some parts, two vessels approach each other obliquely, 
 unite in a single trunk, which follows the mean direction of 
 the two vessels; such is the union of the two vertebral arteries, 
 in order to form the basilar artery, that of the anterior spinal 
 arteries, that of the aorta, and of the pulmonary artery in the 
 foetus, that of a great many veins, &c. 
 
 Generally, vessels anastomose in such a manner as to form 
 
 by their union an arch, from the convexity of which arise 
 
 many branches; this arrangement is observed in the rnesente- 
 
 ric or intestinal vessels, about the articulations, in the hand, 
 
 * in the foot, &c. 
 
 In other places two vessels, each following its direction, 
 communicate by a transverse branch; such is, for instance, the 
 communication between the umbilical arteries in the placenta; 
 such are those of the brain, of the right with the left side, and 
 of the anterior with the posterior part; such are also those of a 
 great many veins and arteries of the limbs. 
 
 In several places, these various and more or less numerous 
 communications form circles or polygons, like the circle of 
 Willis, at. the base of the brain; those of the iris and mouth, 
 that which encircles the stomach, &c. 
 
 In a great number of parts, or almost every way, the vessels 
 which anastomose in an arch, uniting likewise with others 
 proceeding from branches, some being near, and others far- 
 ther removed from the centre of the vascular system, establish 
 collateral ways of circulation: thus, for instance, the circum- 
 
OF THE VESSELS IN GENERAL. 243 
 
 fiexa ilii communicate at the same time above with the vessels 
 of the trunk, and below with the vessels of the knee, and these 
 vessels at the same time communicate also with the branches 
 proceeding from the vessels of the leg. 
 
 Generally the vessel or vessels which result from an anasto- 
 mosis, are more voluminous than either of the anastomosing 
 vessels and less than both united. 
 
 Anastomoses are so much the more frequent as they o.ccur be- 
 tween smaller vessels and in parts the more distant from the 
 centre; they occur also between larger branches in the extre- 
 mities; for instance, in the cavity of the cranium, in the hand 
 and in the foot. In most cases they establish a communication 
 between vessels, whose origin is very near; in some cases 
 they cause vessels, the origin of which is pretty distant, or 
 even very distant, as for instance, from the subclavicular to 
 the inguinal regions. The anastomoses of the sanguineous 
 vessels are more numerous and larger around the articulation, 
 than in the parts between them; those of the veins and of the 
 lymphatic vessels are very frequent between the principal 
 trunks; those of the veins particularly, are much multiplied 
 under the skin. 
 
 We may form an idea of the number and importance of ana- 
 stomoses since the aorta* may be narrowed, obliterated, even 
 tied without preventing the circulation or the injection to 
 reach every part of the body; that the largest veins,t even the 
 venae cavse being obliterated, nevertheless the blood circulates; 
 and that the thoracic ductj has been obliterated or tied with 
 impunity. 
 
 Anastomoses facilitate and render more uniform the circu- 
 lation of the fluids of the body. 
 
 357. The larger vessels follow a pretty straight course, 
 generally parallel to the axis of the body; this is the reason 
 
 * Scarpa on Aneurism. A. Cooper and B: Travers' Surgical Essays, 
 part i. Lond. 1818. 
 
 } J. Hodgson, Affections of the Arteries and Veins. 
 
 t Flandrin, Journal de Medicine, torn. Ixxxvii. Paris, 1791. A. Cooper, 
 in Medical Records and Researches, &?c. Loud. 1813. 
 
244 GENERAL ANATOMY. 
 
 why surgeons prefer making their incisions in the longitudi- 
 nal direction, in order to avoid wounding them. 
 
 In many places, however, vessels have a fluctuating course. 
 The fluctuation of the vessel consists in a deviation or alter- 
 nate undulation of the vessels from a straight lino; it increases 
 when the vessels are turgid, or when a subject is injected, and 
 in the arteries during the systole of the heart; it diminishes 
 under opposite circumstances, and especially by closely dis- 
 secting the vessels. In the vessels of the parts subject to great 
 change of volume, figure and situation, this fluctuation is very 
 well marked; as for instance, the mouth, stomach, intestine, 
 bladder, uterus, the tongue, and testicles before they descend 
 from the abdomen,, and those immediately surrounding the ar- 
 ticulations: in these latter, however, there is less fluctuation, 
 but the vessels are very elastic. 
 
 The vessels of the spleen and brain, and the spermatic veins, 
 form also a great many windings, although they appear not to 
 be intended for the same use. 
 
 The fluctuations of the sanguineous vessels are more strong- 
 ly marked than those of the lymphatic vessels, and those of 
 the arteries more than those of the veins. 
 
 358. The symmetrical distribution of the vessels is very 
 imperfect. This does not exist in the central parts; they are 
 very nearly symmetrical as to their divisions, which belong 
 to symmetrical parts, and have no symmetry in those be- 
 longing to parts which are not symmetrical. The arteries, 
 the veins and lymphatic vessels present equally this disposi- 
 tion. In certain animals and in the embryo, the vascular 
 system is more symmetrical than in the adult man. More- 
 over, besides the general want of symmetry, the vascular 
 system is also subject to many irregularities in its distribu- 
 tion. 
 
 359. The parietes of the vessels adhere by their external 
 surface to the mass of the body in which they are ramified; 
 their internal surface is smooth, polished, humid, and in con- 
 tact with the circulating fluids; it presents a projection where- 
 ever the branches form acute angles with the trunks. The 
 thickness of the parietes, when compared with the relative 
 
OP THE VESSELS IN GENERAL. 245 
 
 volume of the vessel, increases from the trunk to its ramifica- 
 tions. The cavity presents exactly, as we have already said 
 [354,] of the vessels themselves, the cylindric form in each 
 division; that of a cone diminishing in size from the trunk to 
 one of the last divisions; and that of a cone increasing from 
 the trunk to all its ramifications. 
 
 360. The texture of vessels is formed of several layers 
 placed one over the other, and more or less distinct. 
 
 The internal membrane is thin, whitish, more or less dia- 
 phanous, uniform, without any visible fibres, every way con- 
 tinuous, but different in the arteries and veins. It very much 
 resembles serous membranes, and is moistened by a liquid, 
 the origin of which is not well known. It forms, according 
 to the different kinds of vessels, a greater or smaller number" 
 of valves or duplicatures, arranged in such a manner as to per- 
 mit the passage of the fluids in the direction of the circulation, 
 and preventing their retrograde course. 
 
 The external coat, which must not be confounded with the 
 cellular sheath which closely surrounds the vessels, is thicker 
 than the internal, is fibro-cellular, and is generally formed 
 with filaments, which are oblique with respect to the direction 
 of the vessel, and which decussate each other. 
 
 Between these two membranes, a third which is fibrous, is 
 observed, it is distinct in all the arteries that can be dissected, 
 as well as in the larger veins. 
 
 361. The external membrane of the vascular system, and 
 especially the middle coat or membrane of the vessels, which 
 are provided with it, are formed with a particular fibre. This 
 fibre has been named elastic fibre, elastic fibrous tissue, &c. 
 although the greater number of the organs are elastic and 
 fibrous, but because it possesses this property in the highest 
 degree. Its elasticity had already been observed by Nicholls, 
 J. Hunter, and Ed. Home;* some modern anatomists and 
 chemists have made it an object of their study.t 
 
 It not only forms the parietes of the vessels, but of those of 
 
 * Croonian, Lecture an Muscular Motion, in Philos. Trans, ann. 1795. 
 f H. Hauff, de systeme telse elastic^ &c. Tubing*, 1822. Chcvreul, from 
 an unpublished note. 
 
246 GENERAL ANATOMY. 
 
 the air vessels of the lungs ; it also lines some excretory ducts; 
 it forms the envelope of the cavernous body and that of the 
 spleen, and the yellow ligaments of the vertebras; it forms 
 moreover, in various animals, the posterior cervical ligament, 
 an abdominal tunic to the larger mammiferous animals, the 
 ligament which raises the nails of the cat, that which opens 
 bivalve shells; and in the greater number of the mammi- 
 ferous animals, it supplies the place of the little bones of the 
 tympanum. But it is especially in the middle coat of the arte- 
 ries, in the yellow ligaments, and in the ligamentum nuchae, 
 that its characters are most evident. It exists under two 
 principal forms; that of a canal, as in the parietes of the arte- 
 ries; and that of bundles, as in the yellow ligaments. 
 
 This fibre is opaque, of a yellowish white, dry, firm, al- 
 ways arranged in parallel or very slightly oblique bundles, 
 never crossing each other, nor united by the celluar tissue, 
 and very easy to divide. It is extremely elastic, and in some 
 places it may be stretched twice its length; and afterwards it 
 forcibly recoils on itself, resuming its former condition. Its 
 strength in the living body is less than that of the muscular 
 tissue, but is stronger than the latter in the cadaver. In both 
 these states it is much less than that of the ligamentous tissue, 
 which it is almost impossible to extend. It is more tenacious 
 where it exists in bundles, and more brittle in the vessels. 
 
 The elastic tissue contains nearly one half of its weight of 
 water; when it has lost its moisture by disseccation, it acquires 
 a horny appearance, a dark yellow colour, and becomes brittle 
 and diaphanous like horn. If plunged at this time in water, 
 it absorbs with avidity, and assumes its weight, aspect, and 
 former elasticity. It resists maceration for a long time, and 
 the cellular tissue does not become apparent in its structure. 
 The action of fire crisps it but little, and leaves behind very 
 little charcoal. Decoction scarcely crisps it, and extracts from 
 it a small quantity of gelatine, but never melts it, and this 
 operation does not destroy its elasticity. Acids render it 
 but little horny and do not make it transparent; it resists their 
 action for a long time, or experiences no effect at all. Diluted 
 
OP THE VESSELS IN GENERAL. 347 
 
 alkaline solutions do not alter its form, and dissolve it very 
 little. 
 
 The greater number of these anatomical, physical or chemi- 
 cal characters, are altogether the reverse of those of the liga- 
 mentous tissue, and different from those of the muscular fibre, 
 with which the elastic tissue has been very improperly con- 
 founded. It resembles, however, in some respects, the mus- 
 cular fibre, and seems to be of a nature intermediate between 
 this latter and the cellular and fibrous tissues. 
 
 Its vital properties are very obscure, especially in the liga- 
 ments, and even in the larger vessels. Its functions depend on 
 its elasticity, which every way antagonises the action of gravi- 
 tation, or that of the muscles. 
 
 362. The parietes of the vessels are themselves provided 
 with sanguineous and lymphatic vessels, vasa vasorum. The 
 former may be perceived in all the vessels which are not less 
 than half a line in diameter; but they can not be traced into 
 the thickness of the inner membrane. The lymphatics can 
 only be observed on the larger vessels. The vascular system 
 is also provided with nerves* furnished by the spinal marrow, 
 and by the great sympathetic, and which are distributed in the 
 external parts of their parietes. 
 
 363. The vessels whose trunk, branches, and the principal 
 ramifications are placed in the common cellular tissue, after 
 having divided, penetrate into the mass of the organs, there 
 ramify to such an extent as to become invisible to the naked 
 eye, and terminate as we shall mention presently; but the dis- 
 tention of the vessels in the organs varies in several points 
 which it is necessary to treat of successively. 
 
 364. Their origin is more or less distant from their termi- 
 nation, and consequently they have various lengths. Gene- 
 rally, vessels branch off from their trunk very near the organ 
 to which they are destined. When this is not the case, it is 
 owing to some local disposition. Thus the spermatic vessels 
 have their origin at a great distance from the organs in which 
 
 * Wrisberg, de Nereis arteries venasque cornitantibus; in syllog. comm. 
 Getting. 1800. 
 
 33 
 
248 GENERAL ANATOMY. 
 
 they terminate; because primitively the testicles and ovaries 
 were situated near the kidneys. 
 
 365. The number, the volume, and consequently the 
 amount of vessels, as well as the quantity of liquid they carry, 
 vary equally in the different organs. The greater number of 
 organs receive several vessels of each kind: such are, for in- 
 stance, the muscles, the bones, the encephalon, the stomach, 
 the intestines, the uterus, &c. ; some have only a single arte- 
 rial and a venous trunk; such are the spleen, the kidneys, &c. 
 The vessels, almost always, greatly subdivide at the surface of 
 the organs before penetrating into their interior, as is observed 
 in the brain, the bones, the muscles, &c.; sometimes they enter 
 into an organ through one single point, and subdivide within 
 its mass, such as, for instance, the spleen, the testicles, &.c. 
 
 The amount of the vessels, resulting from their number, and 
 from their volume, as well as the quantity of the fluid con- 
 veyed through them, vary greatly. The most vascular parts 
 are the lungs, then the tegumentary membranes, the pia-mater 
 and choroid ; then the glands, the follicles, the vascular gan- 
 glions, the cortical substance of the brain, and the nervous 
 ganglions; then the muscles, the periosteum, the adipose tissue, 
 the medullary nervous substance, the bones, and the serous 
 membranes; then the tendons, the ligaments; finally, the carti- 
 lages and the arachnoid are but little so or not at all; and the 
 epidermis, the nails, the hair, the ivory, and the enamel of the 
 teeth, seem to be altogether deprived of vessels.* 
 
 366. Having arrived in the tissue of the organs, and hav- 
 ing attained a degree of tenuity more or less great, the vessels, 
 by their divisions and subdivisions, by their direction, and by 
 their anastomoses, form a very minute net- work, the form of 
 which, although very diversified, is always the same in the same 
 parts. They present arborizations in the intestines and epi- 
 didymis, stars on the liver, tufts on the tongue, tendrils in the 
 placenta; they have the form of a bottle-brush in the spleen, 
 resembling a bundle of rods in the muscles, curls in the testicles 
 
 * See Soemmering', de Corp. human, fabric:!, V. iv. tmgiologia, 1800. G. 
 Prochaska, Disquisitio anat. physiol. organismi corp. hum, &c. foennae, 1812. 
 Cap. ix. De vosis scmguintis capillaribus, &c. 
 
OF THE VESSELS IN GENERAL. 249 
 
 and in the plexus choroides, fringes in the pia mater, a trellis in 
 the pituitary membrane, tufts in the crystalline; they are arched 
 in the iris, &c. These modes of formation are so constant and 
 regular, that by examining with the microscope a small por- 
 tion of a well injected organ, we may easily recognise to which 
 part it belongs.* 
 
 367. The vessels are more or less diaphanous, according 
 to their thickness. They are whitish. Whatever the density 
 of their parietes may be, especially at their inner surface, they 
 are permeable in the cadaver, and even in the living body, 
 either from without inwards, or from within outwards. Their 
 tenacity or cohesion is considerable ;t but is not the same in 
 the three kinds, in everyone of their parts, nor in the various 
 coats with which they are composed. The same is the case 
 with respect^o their elasticity,^: which is generally con- 
 siderable, ancfwhich exists either in the fibres lengthwise, or 
 in those encircling the vessels. They are evidently irritable, 
 and their vital contractility is generally in an inverse ratio to 
 their elasticity. They are not distinctly sensible. Their 
 power of formation is very active. 
 
 368. The vessels are canals through which the circulating 
 humours continually pass and moisten every part of the body; 
 they together with the heart are the organs or agents of this 
 movement, both by their elasticity and by their organic or vital 
 contractility. 
 
 369. The formation and development of the vascular sys- 
 tem, have been particularly observed in the chicken in its 
 shell, rather less in the foetus of the mammiferous animals, and 
 little in the human species. i 
 
 The veins, especially those of the umbilical vesicle, are 
 formed before the heart and arteries. It is uncertain, if in the 
 allantoid or umbilical vessels, the veins are also formed before 
 
 * See Soemmering loc cit, Prochaska he cit. 
 
 j- Cl. Wintringham, experimental inquiry on some parts of the animal struc- 
 ture; London, 1740. 
 
 $ D. Hoffman, Diss. inaug- med. de elastidtatis effedibus in machind hu~ 
 mana; 1734. 
 
250 GENERAL ANATOMY. 
 
 the arteries. It is very probable that in the body of the foetus 
 the arteries are formed before the veins. 
 
 The vessels are observed in the thickness of the umbilical 
 membrane, under the form of small, rounded vesicles, and se- 
 parated from each other; these vesicles augment in number 
 and unite, which produces a very loose vascular net-work. 
 Their first rudiments are in the beginning deprived of proper 
 parietes, and consist in mere passages made in the substance of 
 the membrane. This substance accumulates by degrees about 
 their circumference, and this forms their parietes. The tex- 
 ture and composition of these parietes, are only developed in 
 time. 
 
 As to the primitive simplicity of the circulation in the fce- 
 tus, its successive complication, the formation of the heart, 
 that of the pulmonary vessels, &c. more particularly belongs 
 to special anatomy, and especially to embryology,* than to 
 general anatomy. 
 
 The number of the vessels generally and their diameter, 
 and consequently their sum total, are, as relate to the mass of 
 the body, so much the more considerable as the animal is 
 nearer the time of its formation. The vessels, in general, 
 especially the sanguiferous, and more particularly the arteries, 
 acquire considerable density in old age. 
 
 370. The circulating system presents little differences 
 relative to the sexes; nevertheless the vessels are rather 
 thicker and firmer in the males. There is no appreciable dif- 
 ference in the races of men. 
 
 Individual varieties, on the contrary, are very frequent and 
 very numerous in this system; they consist particularly in 
 differences of origin, volume, number and precise situation; 
 they exist nearly in the same degree in the three species of 
 vessels. 
 
 371. Under many circumstances,accidental,and commonly 
 very minute vessels, are formed. 
 
 Adhesions, at first simply glutinous, become afterwards 
 vascular. The same is the case with respect to the accidental 
 
 * Ph. Beclard, Embryologie on Essai anat. sur k foetus humain, in 4to. 
 Paris, 1821. 
 
OF THE TERMINATION OF THE VESSELS. 251 
 
 teguments or cicatrices. All the accidental productions ana- 
 logous to the organic tissues, are in the same condition. 
 The greater number of morbid productions, which have no 
 analogous case in the organism, are, on the contrary, deprived 
 of vessels. These latter are formed in the cases alluded to in 
 the same manner as in the embryo. The mass in which they 
 are formed, consisting frequently in a coagulated liquid, at first 
 without vessels, presents in the beginning isolated vesicles, by 
 which uniting, form passages or canals through the substance, 
 or without distinct arid proper parietes; these vessels after- 
 wards communicate with those of the surrounding organs; 
 they frequently remain for some time more or less different, 
 and not unfrequently always so, from the primitive natural 
 vessels, either by their manner of dividing, or particularly by 
 the absence or tenuity and softness of their parietes; in many 
 cases, on the contrary, the vessels acquire in time a texture 
 altogether similar to that of the other vessels. 
 
 372. Amongst the alterations to which the vessels are 
 subject, some are common to the three kinds; such as the di- 
 latation and wounds; the others are peculiar to each of them. 
 The former even present very considerable differences in each 
 species, and require to be indicated separately. 
 
 ARTICLE II. 
 OF THE TERMINATION OF THE VESSELS. 
 
 373. The terminations of the vessels, fines vasorum, are 
 the last ramifications of the arteries and the first radicles of 
 the veins and of the lymphatic vessels. Their knowledge is 
 a subject of minute anatomical investigation, which has most 
 exercised the patience of observers and the imagination of 
 etyologists, who expected, with some appearance of plausibi- 
 lity, to discover in it the secret of the greater number of the 
 functions and of diseases. 
 
 374. In almost every part of the body, the vascular termi- 
 nations are branches and radicles of an extreme tenuity, and 
 which can only be observed by the help of a microscope. In 
 
252 GENERAL ANATOMY. 
 
 some parts, these terminations, and especially the radicles of 
 the veins, are larger, and possess an erectile power, which 
 renders them susceptible of experiencing a more or less consi- 
 derable expansion. Finally, in some others, the terminations 
 of the vessels constitute, by their intermixture, and their com- 
 munication, ganglions or particular vascular enlargements. 
 
 I. OF THE CAPILLARY VESSELS. 
 
 375. The capillary or microscopic vessels,* vasa capilla- 
 ria, thus called in consequence of their tenuity, are much 
 finer than hairs, and can not be perceived with the naked eye; 
 although the radicles of the lymphatic vessels participate in 
 this characteristic, nevertheless, it is especially the sanguineous 
 capillary vessels that we shall treat of in this place. 
 
 376. The ancients, who were ignorant of the art of inject- 
 ing vessels, and that of magnifying objects by the help of op- 
 tical instruments, were not acquainted with the extreme vessels. 
 They believed there was between the last ramifications of the 
 arteries and the first of the veins, an extravasated, spongy and 
 sanguineous substance, called parenchyma by Erasistratus, 
 haimalope by Araeteus, and of which they believed the viscera 
 were especially formed. This opinion, on the termination of 
 the vessels, was adopted almost unanimously by all the ana- 
 tomists, till the period of the discovery of the circulation of 
 the blood, and since that time, by a considerable number of 
 anatomists down to the present day. 
 
 The injections of Ent,t however, by demonstrating the di- 
 rect passage, and without the extravasation of the injected li- 
 quid, from the arteries into the veins; the microscopical ob- 
 servations of Malpighi,J and of Leuwenhoeck, made on the 
 transparent parts of reptiles, fishes, and even of bats, in which 
 the blood is seen passing directly from the arteries into the 
 veins; experiments and observations, repeated since a great 
 
 * Prochaska, de vasis sanguin. capill.; in op. cil. 
 
 f Apologia pro circulat. sanguin. ; in op. Leidae, 1687. 
 
 } De pulmonibusy Epist. ii. in oper. omn. 
 
 Exp, el contemp* arcan. natur. detect. Epist. 65, 67, &c. 
 
OF THE CAPILLARY VESSELS. 253 
 
 many times, must have caused, and indeed have generally 
 caused to reject the supposed parenchyma interposed between 
 the terminations of the arteries and veins, in rendering evident 
 the ramifications which are not visible to the naked eye, the 
 microscopical divisions, and thus establishing a direct commu- 
 nication between them. 
 
 Minute injections and microscopical observations, soon led 
 anatomists to admit, that instead of the parenchyma of the an- 
 cients, every thing is composed of vessels in the body; an 
 opinion which yet divides all the cultivators of the science. 
 
 377. The sanguineous capillary vessels are the last ramifi- 
 cations of the arteries, and the first radicles of the veins, or 
 rather they are intermediate between the arteries and veins, 
 and, as has been remarked in comparing them to the portal 
 system, foreign or indifferent to both. It is in these vessels 
 that, insensibly and without any fixed point, the arteries are 
 converted into veins; of which we may judge by the succes- 
 sive increase or diminution of the size of the vessels in the one 
 or the other direction, by the direction in which the successive 
 divisions or union are made, and at the extremity of the fins 
 and the tail of fishes, by the opposite direction of the course 
 of the blood. However, the capillary vessels have been gene- 
 rally described as the last divisions of the arteries, rather than 
 the beginning of the veins. Whether this be well founded 
 and depend upon the small veins being larger than the small 
 arteries, acquiring a considerable volume after a few re- 
 unions; or whether it is because the veins, almost all provided 
 with valves, and more difficult to inject than the arteries, have 
 been less the object of investigation. These two reasons may 
 have contributed to give more currency to the opinion in ques- 
 tion. 
 
 378. All the capillary vessels, however, have not the same 
 volume. In this respect three degrees of them may be esta- 
 blished, by taking as the largest those which begin to be in- 
 visible to the naked eye, and as the smallest those which ad- 
 mit only one single red globule of blood at a time, and the di- 
 ameter of which, of course, is not much larger than the glo- 
 bule itself. ( 72.) 
 
254 GENERAL ANATOMY. 
 
 The larger capillary vessels experience several successive 
 divisions before they acquire a size capable of admitting a sin- 
 gle red globule of blood. 
 
 These capillaries communicate together by an infinity of 
 anastomoses so as to form a net-work. They constitute the 
 largest portion of the circulating circle, the capacity of the ar- 
 terial system continually increasing from its origin at the heart 
 to the capillary vessels, and that of the venous system decreas- 
 ing from the capillary vessels to the heart. 
 
 The circulating circle being double in man, there are two 
 capillary systems: the one general, between the terminations 
 of the aortic arteries, and the origin of the veins of the body; 
 and the other pulmonary* at the extremities of the vessels 
 which bear this name. It has been advanced, but without any 
 positive proof to support the assertion, that the pulmonary ca- 
 pillary system is as capacious and contains as much blood as 
 the general capillary system. 
 
 There are in the abdomen two other small capillary systems; 
 one between the mesenteric arteries and veins, the other be- 
 tween the hepatic extremities of the vena porta and the origin 
 of the hepatic veins. 
 
 379. The texture of the capillary vessels can not be ob- 
 served with the naked eye. These vessels have very thin and 
 soft transparent parietes, invisible to the naked eye, and slight- 
 ly visible with the microscope, very little different from the 
 substance of organs, and also from the humours they convey. 
 They seem rather formed out of the substance of the organs 
 than provided with its own parietes. It is, however, very 
 probable that the internal membrane of the vessels, at least, is 
 continuous without any interruption, from the arteries to the 
 veins. 
 
 In the living body they are only distinguished by the colour 
 and the direction of the flow of the blood which they contain, 
 and after death by the colour of the matter with which they 
 are injected. They are distinguished from the spongy areolae, 
 and the accidental cavities of the cellular tissue, by their con- 
 stant, continuous, and regular course. 
 
 380. Although the parietes of all the vessels are permea- 
 
OF THE CAPILLARY VESSELS. 255 
 
 ble, nevertheless, this property is particularly observable in 
 the smallest vessels. 
 
 They are very extensible and very contractile. Irritability 
 increases while elasticity diminishes in the vessels in the same 
 degree as they approach their termination. The capillaries 
 are the most irritable.* Their contractility is produced either 
 by local and direct agents, or by the nervous system. 
 
 381. It is in this part of the vascular system that the 
 most important phenomena of the organism occur, at least 
 of the vegetative functions. The capillary circulation, i. e. 
 the passage of the blood through the vessels of this name, 
 is, of all the parts of the circulation, that, which without be- 
 ing independent of the action of the heart, is the least under 
 its control. It is the point of the circle at which the move- 
 ment of the blood is slowest; it is that in which the blood, 
 divided in very small streams, has the greatest number of 
 points of contact with the parietes of the vessels, and the 
 most influenced by the nervous action. The blood takes its 
 regular course through the capillary system by going directly 
 from the arteries to the veins; if it meets an obstacle, many 
 anastomosing vessels are opened and permit it to continue 
 its round. But this system may also be the seat of conges- 
 tions, irritations, and constrictions, which change the ordinary 
 course of the liquids. Thus the application of warm fluids, 
 for a few minutes, to the lower extremities of a frog, produce 
 a dilatation of the capillary vessels, a local and partial stoppage 
 of the circulation, a congestion, in a word, it causes the tis- 
 sues which were before white, to become very red. The same 
 thing occurs, from various causes, on the mammiferous ani- 
 mals and on man. The application of cold or of a diluted acid 
 produces entirely opposite effects. Mechanical or chemical 
 irritation produces at first the latter effect, and afterwards, by 
 a kind of attraction, a concentric afflux of the liquids which, in 
 many vessels, are then pursuing a course opposite to that of 
 the blood. 
 
 * Whytt, Physiological Essays, 8tc. Edin. 1761. H. Van den Bosh, iiber 
 das Hfusketwermogen der Haargefasschen. Monast. 1786. 
 34 
 
256 GENERAL ANATOMY. 
 
 The blood becomes nevous in the general capillary system, 
 and arterial in the pulmonary capillary system. 
 
 382. The sanguineous capillary vessels, such as they have 
 just been described, are not equally abundant, and have not 
 the same volume in all the parts of the body. The amount 
 of the vessels of each part may be esteemed by the redness 
 that it acquires when congested or inflamed, as well as when 
 it is injected : this latter method is even preferable. The most 
 successful injections made, are those of Ruysch, Albinus, Lie- 
 berkuhn, Earth, Bleuland, Soemmering, and Prochaska. 
 
 The injections of Ruysch, by filling the most minute vessels, 
 gave rise to the opinion that the whole of the solid substance 
 of the body is vascular. Ruysch himself, however, acknow- 
 ledged, that there were in the body parts more or less vascu- 
 lar, and others were entirely deprived of vessels. Albinus, 
 in examining injected parts while yet fresh, and also when 
 dried, observed that even after the most successful injections, 
 there remains always more or less substance which was not 
 reached by the injection, according to the nature of the parts: 
 he thus controverted an erroneous opinion, which had espe- 
 cially arisen from the examination of the parts while dried or 
 macerated, so as to cause the parts which can not be injected 
 to disappear, or to be destroyed. 
 
 Microscopical observations and different experiments on 
 living bodies also show, that there are parts more or less vas- 
 cular. Thus, if the mesentery or the webs of the feet of a 
 living frog be examined with the microscope, we shall see 
 that the most minute capillary vessels, those which admit only 
 one globule, are separated by a considerable space, whilst in 
 the pulmonary mucous membrane of the same animal it would 
 be impossible to stick a very fine needle without opening se- 
 veral of these vessels; nor is there, on the surface of the skin 
 of a living man, a point in which a needle would not produce 
 the same effect; while in the ligamentous parts, in the nervous 
 substance, in the cellular tissue, &c. considerable divisions 
 may be made without causing a drop of blood to issue. 
 
 If all the solid parts were vascular, and entirely vascular, 
 there would be no longer any difference between them, all 
 
OF THE CAPILLARY VESSELS. 
 
 the organs would be homogeneous; there would be but one 
 organ. This organic simplicity is only to be met with, on the 
 contrary, in animals deprived of vessels. 
 
 383. The amount of the sanguineous capillary vessels, and 
 their proportion with the solid and non-injectable substance, 
 are not less interesting than their disposition in the several 
 parts of the body. 
 
 The cellular tissue can not be injected. The epidermis, the 
 horny parts, the hair and teeth, are not injectable at all. The 
 adipose lobules are surrounded with a very fine vascular net- 
 work. Cartilages experience no change whatever by injec- 
 tion. 
 
 The serous and synovial membranes are but slightly red- 
 dened by injection, but the masses and the fringes of adipose 
 matter are surrounded with a very beautiful vascular net- 
 work. The skin is the most vascular part. The matter of 
 injection sometimes transuded beyond the dermis into the 
 mucous layer or corpus mucosum. The capillary vessels of 
 the skin, which are at first of the first and second magnitude, 
 acquire the greatest degree of tenuity in penetrating into the 
 papillaB. The recent skin, immediately after being injected, is 
 much more coloured at its external surface; it appears equally 
 coloured throughout, when the uninjectable parts which con- 
 cealed the vessels have disappeared in consequence of desic- 
 cation. The cutaneous and mucous follicles are furnished 
 with a very loose vascular net-work. This is also the case 
 with the microscopic alveoli of the mucous membrane of the 
 stomach and intestines. The papillae of the mucous membrane, 
 like those of the skin, are furnished with an infinite number 
 of capillary vessels, which is also the case with the villosities, 
 at least their adherent extremity. The mucous membrane, 
 in general, is still more injectable than the skin, that of the 
 lungs, particularly, is so in the highest degree. The mem- 
 brane of the pituitary sinuses is much less so than the rest. 
 The conjunctiva reddens moderately, and less by injection 
 than by inflammation. The mucous membrane of the excre- 
 tory ducts, and the glands themselves, are provided with nu- 
 merous capillary vessels. 
 
258 GENERAL ANATOMY. 
 
 The ligamentous tissue receives few blood vessels; the dura 
 mater is somewhat rather better provided; and the perioste- 
 um is reddened a little by injection. 
 
 The bones have but a small number of vessels. The capil- 
 lary vessels of the muscles are abundant; the smallest, which 
 are tortuous, accompany and surround the muscular fibres, fre- 
 quently anastomosing. 
 
 The nervous system is furnished with capillary vessels, 
 which are more abundant in its envelopes and in the cineri- 
 tious substance, than in the medullary substance. The pia 
 mater and the neurilema generally, which differ in this re- 
 spect from the envelopes of many of the viscera, contain the 
 vessels until the greater part of them have acquired a capilla- 
 ry tenuity. The cineritious matter of the brain and the nerv- 
 ous ganglia possess a multitude of capillary vessels of all sizes. 
 The white matter, on the contrary, either of the encephalon 
 or nerves, possesses only very small capillary vessels, and in a 
 smaller number. 
 
 384. There is therefore in the different organs, a greater 
 or less proportion of a substance not vascular, or which at 
 least can not be shown to be so by injections. 
 
 Meyer,* having introduced a colouring matter into the blood, 
 both by absorption and by injection, concluded, from the differ- 
 ent colouring of the parts of the body, that there are two kinds 
 of organs, one set composed for the greater part of capillary 
 vessels, viz: the cellular tissue, the serous membrane, the te- 
 gumentary membranes, and the fibrous or ligamentous tissue; 
 the other, more sparingly furnished with blood vessels, and 
 formed of globules or of an organic pulp, viz: the glands, the 
 bones, the muscles, and the medullary nervous substance 
 
 This proportion also changes with age; at the commence- 
 ment, at least in the ovipara, the blood is seen and presents 
 currents before there are solid parts; soon after, the walls of 
 the vessels are formed. The younger the animal, and the 
 nearer to the foetal state, the greater is the proportion of ves- 
 
 Memoire sur f absorption veineuse, &c. in deutches archiv, &c. and in the 
 Journal complc'mentairc, vol. xi. 
 
OF THE CAPILLARY VESSKLS. 
 
 sels over the non-injectoble parts. In the same degree as it 
 advances in age, on the contrary, the proportion of non-inject- 
 ahle parts increases, and that of the capillary vessels dimi- 
 nishes. 
 
 385. Beyond the capillary blood vessels of the. diameter 
 of a coloured globule, are there other smaller vessels which 
 afford a passage to the colourless part of the blood? This is a 
 question of very difficult solution. 
 
 Boerhaave, Vieussens, Ferrein, Haller, Soemmering, Bichat, 
 Chaussier, and many modern anatomists and physiologists, 
 admit serous vessels beyond the last blood vessels, and Bleu- 
 land even thinks he has demonstrated their existence. 
 
 On the other hand, Prochaska, Mascagni, Richerand, and 
 several others, are of opinion that there are no vessels of this 
 kind. It is necessary to examine the facts and reasons ad- 
 duced in support ofthe.se opinions. 
 
 386. Edmund King was one of the first who substituted 
 for the hypothesis of the ancients, respecting the existence of 
 a parenchyma in the viscera, that of a purely vascular struc- 
 ture, which supposes that there are serous vessels; for the last 
 capillary blood vessels are far from occupying or forming the 
 whole substance of the tissues. 
 
 Vieussens and Boerhaave especially, have admitted not only 
 one, but several orders of decreasing and colourless vessels. 
 The disciples of Boerhaave, Haller, the most celebrated of 
 them, and most of the physiologists up to the present time, 
 have also admitted serous vessels, forming a continuation of 
 the arteries beyond the point at which the veins begin. They 
 found their opinion upon the microscopical observations of 
 Leuwenhoek, who speaks of vessels admitting only serous 
 globules, upon the phenomena of injection, and particularly 
 on those of inflammations, which renders parts naturally white 
 and transparent, more or less red. 
 
 We may add to this, that red and injectable capillary ves- 
 sels known in certain organs, are in so small a proportion to the 
 non-injectable substance, that it is difficult to conceive how 
 their nutrition could occur without there existing circulating 
 
260 GENERAL ANATOMY. 
 
 passages, more extended and more multiplied, than those of 
 the known blood vessels. 
 
 J. Blenland* has added to these reasons an anatomical ex- 
 periment, which, if it were repeated and confirmed, would 
 furnish the most powerful argument in favour of the existence 
 of serous vessels. 
 
 It is known that the red injection, which is fine and very 
 penetrating, easily passes from the arteries into the veins 
 through the intermediate capillary vessels. It is equally known, 
 that colouring matter remains in the capillaries, even whilst its 
 vehicle transudes and is infiltrated in the surrounding sub- 
 stance, where, from the want of colour, it is impossible to dis- 
 cern any form or any particular direction in the passages or 
 reservoirs into which the injection has made its escape. Blen- 
 land formed the idea of combining with the red colouring mat- 
 ter another white matter, which instead of being pulverulent 
 and suspended in the vehicle, was dissolved in it. Having 
 pushed his injection into the arteries of a part of the intestine, 
 of which the vessels were previously filled with a coarser mat- 
 ter and of another colour, and having afterwards separated the 
 peritoneal coat from the intestine, he observed in the external 
 surface of that membrane, by the aid of the microscope, be- 
 sides the capillary blood-vessels, which were all filled with red 
 matter, another order of finer and white vessels, arising from 
 the smallest arteries which had admitted the red injection, and 
 entirely different from the vessels which are filled by ordinary 
 injection. 
 
 But what are these white microscopical vascula or very minute 
 vessels, seen but once, and on a portion of membrane detached 
 from the neighbouring parts? Are they exhalent arterioles, 
 opening at the surface of the peritoneum? Are they serous ar- 
 terioles continuous with serous radicles of veins, and consti- 
 tuting a serous capillary system? Finally, are they lymphatic 
 arterioles, continuous with radicles of lymphatic vessels? It is 
 
 * Experimentum anatomicum, quo arieriohrum lymphaticarum existentia 
 probabilitcr adstruitur, instituturn, descriptum, ct icone illustratum. Lugd. 
 Bat. 1784, 4to. 
 
OE THE CAPILLARY VESSELS. 2G1 
 
 almost impossible to solve these questions. Were they not 
 rather accidental passages? 
 
 Those who have since admitted the existence of serous ves- 
 sels, appear to have been ignorant of this, being the most pow- 
 erful fact in favour of their opinion. Those who have rejected 
 them, have also passed it over in silence. 
 
 The opinion of Mascagni, Prochaska, and others, respect- 
 ing the non-existence of vessels finer than those which give 
 passage to a single coloured globule of blood, may be esta- 
 blished, first, upon the circumstance, that these vessels are 
 easily seen by the aid of the microscope in living animals, and 
 by no means smaller vessels, although the microscope gives so 
 large a volume to the globules of the blood, that it would be 
 easy to distinguish much smaller objects; secondly, upon the 
 circumstance that the red injection, which is very penetrating, 
 does not clearly disclose any other vessels than those which 
 are seen in the living subject. If in this case the parts become 
 more red, especially after desiccation, it may be owing to the 
 dilatation of the vessels, and to the disappearance of the inter- 
 mediate substance. If inflammation reddens the parts still 
 more, it is by the dilitation of the existing vessels, the forma- 
 tion of new ones, and the infiltration of blood between the ves- 
 sels. As to the whiteness or natural want of colour of certain 
 very vascular parts, as the conjunctiva, it depends upon the 
 circumstance, that the capillary vessels being in these parts ex- 
 tremely small, the colour of the blood can not be perceived in 
 them. 
 
 3S8. The question, therefore, which relates to the exist- 
 ence of the colourless capillary or serous vessels, is very diffi- 
 cult or impossible to answer; and when this expression is used 
 in the present work, it is to designate capillary vessels which, 
 whether they contain only the serum of the blood, or the blood 
 in its entire state, but in series of single globules, which pre- 
 vents its colour from being perceived, are colourless in the or- 
 dinary state. It is more consistent however with reason not 
 to admit the existence of vessels which no one has ever seen. 
 389. In the double circle of the circulation, the evident 
 communication of the arterial and venous trunks occur in the 
 
262 GENERAL ANATOMY. 
 
 heart, and that of the lymphatic trunks with the venous trunks 
 near that organ, in the subclavian veins. But in the points di- 
 ametrically opposite to this double circle, in the capillary sys- 
 tem, the communication is not so obvious. The ancients sup- 
 posed that of the arteries with the veins, but did not believe 
 the communication to be direct. The discovery of the circu- 
 lation of the blood, while it made this communication to be 
 necessarily admitted, still left its mode undecided. We have 
 already seen, that microscopical observations and injections 
 agree in demonstrating this communication, and even showing 
 that it is direct. 
 
 Microscopical observations have demonstrated* it in the 
 transparent parts of cold blooded oviparous animals, in the in- 
 cubated egg of birds, and even in the transparent parts of 
 mammiferous animals. 
 
 Injection has demonstrated it in almost every part of the 
 body of man and animals,! either by forcing the matter through 
 the arteries, or by pushing it through the veins into parts, as 
 the intestine, in which the veins have no valves. 
 
 Some anatomists had even admitted arterio-venous commu- 
 nications between vessels visible to the naked eye, and of a cer- 
 tain calibre; thus Casserius represents them as occurring in the 
 liver, Riolan describes them as happening after a cured aneu- 
 rism, Lealis notices such communications between the sper- 
 matic arteries and veins. These are errors, that is to say, ill- 
 observed facts, which have been contradicted by Albinus and 
 Haller. 
 
 The communications between the arteries and veins are all 
 capillary and microscopical, but it appears, that in cold blooded 
 animals at least, there are some which permit several coloured 
 globules to pass at once, and others a single one only. 
 
 The disposition of these passages of communication has 
 been observed in animals. They consist, sometimes, simply 
 
 * Malpig-hi, be. clt. Leuwenhoeck. be. cit. Spallanzani, ExpsrL sur la 
 circulation, page 255. 
 
 f See particularly: Ruysc/t Thes. anat. Winslow, mem. de Facad. dts 
 sciences. Haller, de Fabric^ corp. human?', vol. i. Mascag-ni. vas. lymph. &fr. 
 prodromo &c. Proehaska, lur. cit. Reissessen, de structure pnhnon. 
 
OF THE CAPILLARY VESSELS. 263 
 
 of a change of direction or a bending of a minute artery, which 
 becomes a venous radicle; at others a capillary artery and 
 vein parallel to each other, also exchange communicating radi- 
 cles, at the point where the artery changes into a vein; again, 
 and frequently, several capillary arteries terminate or are con- 
 tinued into a single capillary vein. In all cases the commu- 
 nicatiqn occurs in vessels of the capacity of from one to four 
 or five coloured globules. 
 
 330. Modern physiologists have recently raised doubts 
 respecting the direct communication of the arteries and veins. 
 Doellinger thinks that the arteries, at their extremity, cease 
 to have any parietes, and that the blood flows uncontined in 
 the solid substance of the body, which he calls mucous; that 
 at this point, one part of the blood is converted into mucous 
 substance, and that another part of it continues its course 
 joined to sanguified mucous substance, which is set in motion 
 in liquid mass, and penetrates into the venous and lymphatic 
 vessels, arising from the mucous substance as the arteries ter- 
 minate in it. 
 
 Wilbrand goes still farther, and admits a still more com- 
 plete metamorphosis in the circulation; according to him the 
 whole of the blood is converted into organs, or into mucous 
 substance and into secreted fluids, and the organs becoming 
 fluid in the same degree, is converted again into venous fluid 
 and lymph, which continue the circulation, and also become 
 the matter of excretions. 
 
 According to one of these opinions, a part, and according 
 to the other, the whole of the blood becomes solid, and like- 
 wise a part or the whole of the organs is rendered fluid at 
 each round of the circulation. In the one as in the other, the 
 solid mass of the body is interposed between the terminations 
 of the arteries and the origin of the veins and lymphatics. They 
 both suppose that the microscopical inspection of living ani- 
 mals and injections are deceitful means of determining the 
 communication between the arteries and veins. 
 
 391. The direct continuity of the arteries and lymphatics 
 is not so well demonstrated as that of the veins and arteries. 
 Many anatomists, however, have admitted, with Bartholin, 
 35 
 
2f>4 GENERAL ANATOMY. 
 
 the continuity of the lymphatic vessels with the capillary arte- 
 ries finer than those which allow the passage of the coloured 
 globules of the blood. Haller, and most of the anatomists who 
 have lived since his time, admit no other origin to the lympha- 
 tic vessels than the tegumentary membranes. Some authors, 
 among whom is Mascagni, in admitting that lymphatic ves- 
 sels likewise arise from the parietes of blood vessels, thus in- 
 directly admit a communication, although they reject a direct 
 continuation. 
 
 The inspection of living animals discloses nothing respect- 
 ing this communication. Injections sometimes pass, and even 
 frequently, but ordinarily colourless, from the arteries into 
 the lymphatic vessels; which may depend on the transuda- 
 tion in the cellular substance, and on the passage into the 
 lymphatics, which arise from it; or on the passage of the mi- 
 nute arteries into the lymphatic vessels of their parietes ad- 
 mitted by Mascagni, as well as upon a direct and immediate 
 communication, which consequently remains very doubtful. 
 
 392. The serous capillary vessels which have been ad- 
 mitted beyond the capillary blood vessels, much more from 
 physiological considerations, than from positive anatomical 
 demonstration, is not the only hypothesis of this kind. Ab- 
 sorption and secretion being certain and evident facts, as al- 
 ready announced by the father of medicine,* many have been 
 the researches in order to find, by what passages substances 
 issue from the vascular system, and by what passages they 
 enter it. Without ever having seen them, they have been 
 described, the one under the name of exhalent or secretory 
 vessels, the other under that of absorbent or inhalent vessels. 
 
 The exhalent vessels have been admitted by Haller, Hew- 
 son, Soernmering, Bichat, Chaussier, &c. as being very simple 
 vessels, appearing to be very minute and short productions of 
 the capillary arteries, and diffused in the tegumentary and 
 serous membranes, and the cellular tissue. 
 
 Other anatomists, such as Mascagni, Prochaska, and Riche- 
 
 * AA.oy, )V9crxf, 'c txTrvw, X.M s/V-mov oAcv TO rapx. Epedem. bib. vi. 
 sect. vi. 
 
OF THE CAPILLARY VESSELS. 265 
 
 rand, admit, on the contrary, the opinion that it is by laternal 
 pores, organically arranged, that secretion or exhalation oc- 
 
 
 
 curs. 
 
 Hunter had even admitted that it was by pores or inorganic 
 interstices that secretion took place, precisely in the same 
 manner as transudation in the dead body. Hewson and Bi- 
 chat have controverted this opinion. 
 
 The real passages, however, of exhalation or secretion are 
 entirely unknown. All we know on this subject, is merely 
 this, that in the living body, fluids issue under the form of 
 vapour from all points of the capillary system; and that seve- 
 ral are observed in a liquid form, or even more or less con- 
 crete; while in the dead body fine injections, in passing from 
 the arteries into the veins, ooze out on the surface of the skin 
 and mucous membrane, in the mucous and cutaneous follicles, 
 in the excretory ducts of the glands, on the free surface of the 
 serous membranes, and in the mucous, areolar or cellular 
 substance, which constitutes the solid mass of the body; but 
 never, and nowhere are there seen ramuscules arising from 
 capillary net-works and terminating by an open extremity. 
 The passages of exhalation or secretion are therefore un- 
 known. It is very probable that it occurs through the solid 
 and porous substance of the body. Secretion, fiawever, is an 
 organic or vital phenomenon entirely different from transuda- 
 tion in the dead body, as is demonstrated by the difference 
 which the various secreted humours present, and the differ- 
 ences of quantity of these humours. The names of exhaling 
 or secreting vessels can only therefore, designate the unknown 
 passages through which the molicules, formed by the mat- 
 ter of the intrinsic and extrinsic secretions, issue from the 
 circulation. 
 
 393. Nearly the same may be said respecting the passages 
 or mechanism of absorption. The absorbent vessels, accord- 
 ing to the idea entertained of them, are radicles open at one ex- 
 tremity, similar to the puncta lachrymalia, and continuous at 
 the other, either with the venous and lymphatic net-work, or 
 with the lymphatic vessels alone, or with the veins alone, of 
 which they are thus the origin. Now, neither these canals 
 
GENERAL ANATOMY. 
 
 nor their patelous mouths have ever been seen. The follow- 
 ing are the opinions and facts known with respect to this nice 
 point of anatomy. Aselli has said, with reference to the lac- 
 teal or chyliferous vessels: " ad intestina instar hirudinum 
 orificia horum vasorum hiant spongiosis capitulis" Hel- 
 vetius asserts that the intestinal villosities have spongy orifices. 
 Lieberktihn speaks of a spongy or cellular ampulla. Hewson 
 rejects the belief in this ampulla. Cruikshank describes and 
 figures twenty or thirty openings, each larger than a globule of 
 blood at the summit of each villosity. Sheldon makes the vil- 
 losities terminate by a spongy tissue, and appears to confound 
 the follicles with them. Mascagni could see no orifices at the 
 summit of the villosities. Feller and Werner describe an am- 
 pulla, and trace vessels into it. Bleuland admits openings at 
 the summit of the villosities. Scemmerring observes that from 
 six to ten absorbent orifices may be seen in each of them. 
 Hedwig considers the ampulla as spongy, and describes their 
 summit as having one orifice or more, or none Rudolphi has 
 never seen any orifices, and those which have been admitted 
 seem to him to depend on optical illusions. This is quite suf- 
 ficient in order to conclude, that the orifices which have been 
 described do not distinctly exist. We must add, however, 
 that when a very penetrating injection is thrown into the in- 
 testinal veins, the matter in passing into the arteries, transudes 
 also at the free surface of the mucous membrane. It is known 
 with respect to the skin, that when a lymphatic vessel of that 
 membrane has been injected, if the mercury be pushed back 
 towards the roots of the vessels, it at length issues from its free 
 surface, as remarked by Haas. Mascagni has made this experi- 
 ment, and any person may easily repeat it, on the sub-perito- 
 neal lymphatic vessels of the liver. Finally, Carlisle asserts 
 that he has seen orifices of lymphatic vessels in a cell of the 
 cellular tissue. 
 
 However doubtful and contradictory the facts may be, the 
 following is the opinion generally admitted, namely, that at 
 the surface of the tegumcntary and serous membranes, in the 
 areolae of the cellular tissue, and according to Mascagni, at the 
 very surface of the vessels, there are orifices of absorbent radi- 
 
OF THE CAPILLARY VESSELS. 267 
 
 cles leading, according to the greater number of modern wri- 
 ters, into the lymphatic vessels only, but according to the 
 anatomists anterior to Haller,and some more modern than him, 
 into the veins only; and according to others, both into the ca- 
 pillary blood-vessels and lymphatics. Prochaska adds to this, 
 among the passages of absorption, the organic porosities of the 
 vessels, which would thus be, at once, the passages of exhala- 
 tion and inhalation. Absorption has also been considered as 
 a purely physical phenomenon, comparable to capillary attrac- 
 tion or imbibition, by adducing in support of it, the absorption 
 which occurs in the dead body. 
 
 The fact is that the passages of inhalation are unknown. 
 They appear to be like those of exhalation, the porosities of 
 the solid and permeable substance of the body. Absorption, 
 however, like secretion, is an organic and vital phenomenon 
 altogether different from imbibition in the dead body, as is de- 
 monstrated by the selection of the substances absorbed, and by 
 the modifications which the activity of absorption presents in 
 various cases. When, in this work, the term absorbents is 
 used, it is to designate by a single word the unknown passages 
 by which foreign substances enter, and those by which the 
 matters of the intrinsic absorptions pass into the circulatory 
 apparatus.* 
 
 394. Imagination has not stopped at the creation of exha- 
 lent and inhalent vessels, of which we have been speaking; 
 nutritive vessels have been also supposed. 
 
 The following are the principal opinions entertained on this 
 subject. Boerhaave and R. Vieussens having admitted colour- 
 less and decreasing vessels, the former conceived the body en- 
 tirely constructed of vessels, even those parts which can not 
 be injected. According to Boerhaave's system, the smallest 
 elementary fibres form minute membranes, rolled upon them- 
 selves, to constitute the smallest nervous vessels. From these 
 smaller vessels result the vascular membranes forming larger 
 vessels, and so on to the largest ones. He also determined 
 
 * See experiments on Edosmose and Exosmose in the No. 7 of the Ameri- 
 can Journal of Med. Sciences. TAAVS. 
 
268 GENERAL ANATOMY. 
 
 that the smallest nervous vessels contain an aqueous fluid, serv- 
 ing for feeling, motion, and at the same time nutrition. 
 
 The opinion of Mascagni as to the elementary composition 
 and nutrition of the parts, does not differ much from that of 
 Boerhaave. According to Mascagni, the division of the arte- 
 ries finishes at the point where, or having arrived at the tenui- 
 ty of a red globule of blood, they are converted into veins. 
 There, they are furnished with exhalent porosities, as well for 
 the secretions as for nutrition. In all parts there are orifices 
 of absorbent vessels for taking up and containing the nutritive 
 molecules. The elementary parts consist of absorbent vessels: 
 these, by their union, constitute the most simple membranes 
 and the smallest blood vessels, which form the most com- 
 pound membranes. 
 
 In these two hypothesis, every thing is vascular, and nutri- 
 tion happens in the vessels; in the first, in the finest ramifica- 
 tions of the capillary arteries, in the second, in the finest radi- 
 cles of the absorbents. In both, the vessels constitute the mass 
 of the body, and are truly in a continual state of circulation. 
 
 Bichat's opinion respecting the nutritious vessels and nutri- 
 tion, is somewhat different. According to this author, each 
 molecule of the organs is in a manner placed between two 
 patulous vessels; the one a nutritive exhalent which had de- 
 posited it, and the other a nutritive absorbent, destined to take 
 it up again. 
 
 Prochaska, while he admits the direct communication be- 
 tween the arteries and veins, supposes that it is by the porosi- 
 ties of the parietes of the vessels and the general permeability 
 of the substance which forms the mass of the body, that nutri- 
 tion occurs. 
 
 395. Nutrition, whatever may be its immediate channel, 
 presents a continual two fold motion of composition and de- 
 composition. The simplest animals directly inhale and exhale 
 the materials of this double phenomenon. Other animals, of 
 a more complex organization, have a tegument more or less 
 prolonged into the mass of the body, conveying there and 
 taking up again the matters which are added to it, and those 
 which are separated from it. Others, still more complex, have 
 
OF THE ERECTILE TISSUE. 269. 
 
 other organs, vessels, which transport from the surfaces into 
 all parts of the mass, and hence back to the surfaces, the mat- 
 ters of absorption and secretion. In certain animals provided 
 with vessels, among which is man, their number is so great, 
 that they seem to occupy and form the whole mass of the 
 body. But, besides the above considerations, which are de- 
 rived from analogy, the arguments derived from inspection 
 also show that the vessels only traverse the mass of the body, 
 and do not constitute it. Observation also shows that, what- 
 ever may be the tenuity or softness of the last capillary ves- 
 sels, the arteries and veins form continuous canals. 
 
 Observation teaches us, that new substances enter into the 
 vessels, and that others also unceasingly issue from them. 
 But this two-fold passage takes place in the finest parts of the 
 vessels, and by paths invisible even with the best optical in- 
 struments; the substances themselves circulate through these 
 passages in a state of division, in vapour, which eludes the 
 senses, and is imperceptible with the best microscopes. This* 
 passage, whether it occurs from without inward, or from with- 
 in outward, in extrinsic absorptions and secretions, or whether 
 it takes place in the closed cavities of the body, always ap- 
 pears to be performed through the intervention of the solid 
 and permeable substance of the body; that is to say, of the 
 substance called cellular, which, by imbibing, transmits in- 
 wards or outwards the inhaled or exhaled molecules. 
 
 The same appears to be the case with respect to nutrition. 
 The vessels deposit and take up under the form of vapour, 
 and by invisible passages, in the cellular substance, the mole- 
 cules of the composition and decomposition of the organs. 
 
 But all these phenomena, which are apparently physical, are 
 modified by the organized and living body in which they oc- 
 cur. It is especially to the unknown cause of these pheno- 
 mena, that the name of vital power has been given, or more 
 particularly, that of power of formation. 
 
 II. OF THE ERECTILE TISSUE. 
 
 396. The erectile, cavernous or spongy tissue, consists 
 of terminations of blood vessels, and especially of the radicles 
 
270 GENERAL ANATOMY. 
 
 of veins, which, instead of being capillary, have more width, 
 are very extensible, and are connected with numerous nervous 
 filaments. 
 
 397. This tissue was first observed in the penis, where its 
 dimensions are very considerable. Vesalius* speaks of it in 
 these terms: corpora hcec (cavernosd) enata adeumfere mo- 
 dum, etc si ex innumeris arteriarum venarumque fasciculis 
 qiiam tenuissimis, simulque proxime implicatis, retia quae- 
 dam ejformarentur, orbiculatim a nervea ilia membranea- 
 que snbstantia comprehensa. Malpighit appears to have 
 made the same observation: sinuum speciem in mammarum 
 tubulis et in pene habemus; in his nonnihil sanguinis re- 
 peritur, ita ut videantur venarum diverticula, vel saltern 
 ipsarum appendices. Hunter^ has seen the same thing with 
 reference to the spongy tissue of the urethra; " It is well to 
 remark," says he, "that the spongy body of the urethra and 
 glans penis are not spongy or cellular, but consist of a plexus 
 'of veins. This structure, he adds is visible in the human sub- 
 ject, but much more distinctly in some animals, as the horse 
 &c." 
 
 The greater part of the anatomists, however, who have ex- 
 amined the structure of the penis, and among other De Graaf, 
 Ruysch, Duverney, Boerhaave, Haller and his disciples, hav- 
 ing mistaken the nature of the cavernous and spongy tissues 
 of the penis, and having considered them as being loose and 
 elastic cellular tissue, forming cells, and interposed between 
 the arteries and veins, most modern anatomists have adopted 
 this error. Duverny, Mascagni, Cuvier, Tiedemann, Ribes, 
 Moreschi, Panizza, Farnese, &c.,have made accurate observa- 
 tions on the erectile tissue of the penis of the elephant, horse, 
 man, &c., as well as on the clitoris of their females. 
 
 398. Although the erectile arrangement of the vessels exist 
 in many parts of the body, nevertheless, there is a certain num~ 
 bes in which it is much more evident. These are the corpus 
 cavernosum of the penis and clitoris, the spongy body of the 
 
 * De carp' Hum. Fabried. Lib. v. cap. 14. 
 
 | Diss. Epist. Varii Jlrgum. In op. omn. vol. ii. 
 
 4 Observations on certain parts of the animal economy. 4to. London, 1786. 
 
OF THE ERECTILE TISSUE. 271 
 
 urethra, the nymphro, the nipple, the papillcc of the tcgumen- 
 tary membranes, &c. 
 
 399. The erectile tissue is of very large dimensions in the 
 organs of copulation. Though it does not present the same de- 
 velopment in the papillae, yet it may be very distinctly ob- 
 served in them. 
 
 The papillae, those of the tongue in particular, consist of en- 
 larged soft nervous filaments, destitute of neurilema, inter- 
 mingled with an innumerable multitude of capillary blood- 
 vessels, tortuous, arched, and anastomosing with each other, 
 the whole enveloped and collected together by a soft and mu- 
 cous cellular tissue. In a state of rest these papillae are small, 
 soft, pale, and indistinct. In that of erection, on the contrary, 
 they are enlarged, raised up, of a red colour, swollen with 
 blood, and possessed of great sensibility. 
 
 The nipple or the papilla of the mamma3, appears to differ 
 from the others only in being of larger dimensions. The skin 
 and mucous membrane present the papillary and erectile dis- 
 positions in various degrees, in their whole extent. The 
 volume of the nerves and the quantity of the blood-vessels, 
 are every where proportionate to the degree of sensibility. 
 The skin of the pulp of the fingers, which is very vascular and 
 nervous, experiences a degree of swelling, and of manifest red- 
 ness during the act of touching, proportionate to its perfection. 
 400. The erectile tissue of the organs of copulation differs 
 from that of the papillae only in having its dimensions much 
 larger. That of the corpus cavernosum of the penis presents 
 the following disposition. It is enveloped by a sheath of elas- 
 tic fibrous tissue, which sends prolongations into its interior. 
 The two dorsal arteries of the penis are accompanied by an 
 azygos vein forming a plexus, and by nerves of great size. 
 The arteries send into the interior numerous minute branches 
 accompanied by nerves, and the veins receive numerous radi- 
 cles through the sheath. The interior is composed of arterial 
 ramifications coming from the doral arteries, and central ar- 
 teries, and of very numerous large veins, intermingled in all 
 directions, and anastomosing a multitude of times with each 
 
 other. These branches of veins present dilatations and wide 
 36 
 
272 GENERAL ANATOMY 
 
 communications. When one of the arteries of the penis is in- 
 jected, the injection, if very fine and penetrating, after filling 
 the arterial ramifications, and the internal venous plexus, which 
 constitutes the corpus cavernosum, and thus producing erec- 
 tion, returns by the dorsal vein. The corpus cavernosum is 
 still more easily filled by injecting through the vein. Thus 
 the pretended cells of the corpus cavernosum, are merely very 
 large roots of veins forming a complicated plexus, and anasto- 
 mosing like capillary vessels. 
 
 The erectile tissue of the urethra and glans have the same 
 disposition; the same is the case with respect to that of the 
 clitoris and nymphae. 
 
 Erection, in the organs of copulation as in the papillae, is 
 produced by the repletion of the erectile vessels. This reple- 
 tion may depend on the afflux of arterial blood, which is ac- 
 companied by an exaltation of the sensibility, and the reten- 
 tion of the venous blood, or by both causes united. 
 
 401. There is still a part whose texture and phenomena 
 greatly resemble those of the erectile organs: this is the spleen, 
 which, by this means, seems to be a diverticulum of the blood. 
 If the spleen be exposed in a living animal, and the course of 
 the blood in the splenic vein be arrested by pressure, this or- 
 gan swells and greatly augments in size; but it quickly assumes 
 its natural appearance as soon as the circulation is re-establish- 
 ed. The accessions of intermittent fever are accompanied, 
 during the chill, by a manifest swelling of this organ, which is 
 more or less completely dissipated when the accession is at an 
 end. It would appear that the same thing takes place during 
 digestion. 
 
 402. The erectile tissue is sometimesaccidentally developed 
 in the organism. This production has been described under 
 the names of varicose tumour, aneurism by anastomosis, aneu- 
 rism of the smaller arteries, telangiectasis, &c. 
 
 Its anatomical characters are precisely the same as those of 
 the natural erectile tissue. It is a more or less voluminous, or 
 more or less circumscribed mass, sometimes surrounded by a 
 thin fibrous envelope, presenting internally an appearance of 
 cells or spongy cavities; consisting in reality of an inextricable 
 
OF THE VASCULAR GANGLIA. 
 
 net-work of arteries and veins, which communicate by innu- 
 merable anastomoses, like the capillary vessels, but much 
 wider, especially the veins, easily injectable by the neighbour- 
 ing veins, which are sometimes varicose, but with difficulty 
 by the arteries. 
 
 This alteration most commonly exists in the substance of 
 the skin, and to a greater or less extent. It then sometimes 
 resembles the crest and other similar parts of the gallinaceous 
 birds. The skin of the face, and especially that of the lips, is 
 frequently the seat of this alteration. It is observed in the 
 subcutaneous cellular tissue, or more or less deep; it has been 
 seen occupying a whole member; it is even asserted to have 
 been observed in some viscera. 
 
 This production is the seat of a vibration, a rustling, and a 
 pulsation, more or less manifest, and which are increased by 
 all the causes which excite the activity of the general circula- 
 tion; but the tumours which it forms, even in the skin, are by 
 no means susceptible of a kind of isolated erection. U is most 
 commonly congenital, and at other times appears to depend 
 on an accidental cause; it sometimes continues without change, 
 at others, which is the most common case, it augments contin- 
 ually in size by the dilatation of its internal cavities, and at 
 length bursts, giving rise to haemorrhages, which are difficult 
 to repress. 
 
 Around the arms there occur hemorrhoidal tumours, resem- 
 bling the spleen in appearance, which constitute a variety of 
 this accidental erectile tissue. 
 
 III. OF THE VASCULAR GANGLIA. 
 
 403. The vascular ganglia, adenoid or glandiform organs, 
 or aporic glands,* confounded under the common name of 
 glands with organs of excretory secretion, are also parts in 
 
 * Queitschius, De glandulls coeds, &c. in select, med. Franco/. Hendy, 
 Essay on glandular secretion. Hewson, Descriptio glandul. SJc. opus posthum . 
 in op. omn. H. F. F. Leonhardi, De glandulis in genere et glandulis apori- 
 cis t &fc. Dresden, 1813. 
 
274 GENERAL ANATOMY. 
 
 which the termination and communications of the vessels 
 aflfect particular dispositions. Hensinger has given to them 
 the name of parenchymatous tissue. 
 
 Their texture results from the union of several other tissues. 
 They are formed of modified cellular tissue, of blood vessels 
 and lymphatics, and of nerves; the whole inclosed in an enve- 
 lope, which send prolongations into the interior. They are 
 all situated in the course of the lymphatic and venous circu- 
 lation, and seem to be destined to make the absorbed sub- 
 stances undergo an elaboration, and to prepare their assimila- 
 tion; they thus appear to be in a kind of antagonism to the 
 true glands or the organs of excretion. The vascular ganglia 
 differ from each other in the quantity and the species of tissue 
 of which their mass is formed, in the proportion of vessels 
 and nerves, and in the mode of communication of the vessels. 
 
 404. The adenoid ganglia may be distinguished into two 
 kinds: 1st, the lymphatic glands or ganglia; and 2dly, the 
 ganglia of the blood vessels, which are the thyroid gland, the 
 thymus, the surrenal capsules, and the spleen. 
 
 The former of these will be described along with the lym- 
 phatic vessels, (sect, iv.) The others, which form a less na- 
 tural group, belong principally to special anatomy. They have, 
 however, some general characters. The ganglions of the 
 blood vessels* are larger and much less numerous than the 
 lymphatic ganglia. They are of a brownish-red colour, glo- 
 bular and granular. They present internally distinct cavities, 
 filled with a fluid, but little ramified and closed on all sides. 
 It was believed, at divers epochs, that excretory ducts had 
 been discovered in them, but these supposed discoveries have 
 not been confirmed. These ganglia are so intimately con- 
 nected with the blood vessels and lymphatics, and especially 
 with the thoracic duct, that they have been supposed, with 
 
 * Boeckler, de Functionibus glanduhs thyreoidx, thymi, atque glandul 
 9upraren. t fcfc. Argentor. 1753. Hecker, iiber die verrichtung der kleinsten 
 scklagaden und einger cms einem gewebe der feinsten gefasse bestehenden ein- 
 geweide, der schild-und brust-druse, der milzes, der nebennieren und nachge- 
 burt, Erfurt, 1790. 
 
OP THE ARTERIES. 275 
 
 much probability, to have a very great influence upon the per- 
 fecting of the lymph and chyle, and on the formation of the 
 blood. 
 
 
 SECTION II. 
 
 OP THE ARTERIES. 
 
 405. The arteries,* qrteriae, are the vessels which convey 
 the blood from the heart to all the parts of the body. 
 
 406. Hippocrates and his contemporaries gave the name 
 of veins to all the vessels and canals, with the exception of 
 the trachea, which they called artery. Aristotle is the first 
 who speaks of the aorta, which he names the small vein. 
 Praxagoras gives the name of artery to the aorta and its 
 branches, which he believed to contain a vapour. The school 
 of Alexandria distinguishes the arteries from the veins by the 
 thickness of the walls, and admits that the blood may, under 
 certain circumstances, pass into the arteries. Galen, the 
 greatest anatomist of antiquity, tries to prove that the arteries 
 are full of blood in their natural state. He considers the ve- 
 nous system and the arterial system each a tree, whose roots, 
 implanted in the lungs, and whose branches, distributed 
 throughout the body, meet at the heart. It was not until Ve- 
 salius, that the first rudiments of the art of injecting the blood 
 vessels were known, and it was not until his day that some 
 notions respecting the texture of the blood vessels are to be 
 found. Their functions and alterations have only been known 
 in later times. 
 
 407. There are two arterial trunks; the aorta and the pul- 
 monary artery, both have an arborescent disposition, and pre- 
 
 * BassueJ, nouvel aspect de Pinterieur des arteres, et de leur structure par 
 rapport au cours du sang; mm. pretcnt. de math, et de phys. torn. I. ann. 
 1750. D. Belmas, structure des arteres, leurs proprittts, kurs functions et 
 kurs alterations organiques. in 4to. Strasbourg, 1822. Ch. H. Ehrmann, 
 the same title, place and date. 
 
276 GENERAL ANATOMY. 
 
 sent an origin, a trunk, branches, twigs, and ramusculi, be- 
 coming smaller and smaller until they reach their termina- 
 tion. 
 
 Each of the arterial trunks arises from a ventricle of the heart, 
 and does not present here a continuation of the substance of 
 the heart, as has even recently been advanced, but an intimate 
 and very remarkable' connexion of the middle membrane of 
 the artery is divided into three festoons, bordered with liga- 
 mentous tissue, the orifice of the ventricle is furnished with a 
 ring of the same tissue, the extremity of the festoons of the 
 artery is firmly fixed to the orifice of the ventricle, and the 
 triangular intervals of the dentations are likewise occupied by 
 ligamentous membranes; the internal membrane of the vessel 
 is continuous with that of the heart, and the external mem- 
 brane is united to the substance of that organ. 
 
 The trunks, the branches and all the divisions of the arteries 
 are obviously cylindrical. There are nevertheless exceptions; 
 some arteries enlarge as they advance, while others seem to 
 contract. The arterial cylinders gradually diminish from the 
 trunks even to the last ramifications. 
 
 Generally the sum of the calibre of the branches is greater 
 than their main trunk, but to this there are exceptions; thus 
 it is not evident, that the carotid and brachial arteries have 
 together a greater capacity than the trunk of the innominata; 
 neither is it certain, that the radial and cubital arteries united, 
 have a greater capacity than the brachial. We must not con- 
 found, in this comparison, the external diameter with the ca- 
 pacity. Besides it very often happens, that the capacity of 
 the arterial branches changes, without an appreciable change 
 in their size; and to cite only an obvious example of it, the 
 uterine arteries augment considerably during pregnancy, while 
 the hypogastric artery which furnishes them, increases but 
 little, and the primitive iliac artery not in an appreciable 
 manner. 
 
 The variable number of the successive divisions of the arte- 
 ries, their mode of division, and the angles which are found 
 between the branches and the trunks, have been indicated 
 [354, &c.] as well as the anastomoses and the lateral passages 
 
OP THE ARTERIES. 277 
 
 that they present to the circulation. The same is the case 
 with their flexuosities. 
 
 The termination of the arteries, when they become capillary 
 and microscopic, occurs by their being continued into veins, 
 either by red capillary communications, or by communications 
 of colourless vessels in consequence of their extreme minute- 
 ness. 
 
 408. The arteries are cylindrical when examined inter- 
 nally, their section is circular, excepting in the largest arte- 
 ries, which, when empty, are slightly depressed, and present 
 an elliptic section. 
 
 Each of the two arterial trunks is furnished with three valves 
 at its origin in the heart. These semi-lunar valves are attached 
 by their convex edge to the contour of the festoons of the ar- 
 tery; their free margin is straight and somewhat thick, espe- 
 cially at the middle, which present a small enlargement. One 
 face is turned toward the parietes of the artery, and the other 
 towards the axis of the vessel. These valves are formed by the 
 inner membrane of the arteries, doubled on itself, and contain- 
 ing in its substance a thin layerof ligamcntous or fibrous tissue; 
 their free margin contains a small cord of this tissue, and its 
 middle a fibro-cartilaginous point. When these valves fall, the 
 face, which corresponds to the ventricle, becomes convex, and 
 the other, which corresponds to the canal, becomes concave; 
 their free edges meet, touch each other, and they exactly close 
 the vessel. In all the rest of their extent the arteries are de- 
 prived of valves. 
 
 The internal surface is smooth, polished, and moistened. 
 The external surface corresponds to the common and particular 
 cellular tissue in which the arteries ramify. The cellular tissue 
 moulded around them, or separated by their presence, forms a 
 cellular sheath for them. This sheath is confounded externally 
 with the rest of the cellular tissue, or with the substance of the 
 organs; internally it is united to the artery in so loose a man- 
 ner, as to permit the latter to slide easily in its interior during 
 the different motions, and to retire within it by contracting in 
 the longitudinal direction when it is divided. This sheath is 
 pretty firm around the arteries of the limbs; in the thorax and 
 
27$ GENERAL ANATOMY. 
 
 abdomen the sheath of the arteries is in part formed by the 
 serous membranes. That of the spermatic arteries is remarka- 
 ble for its looseness, and that of the arteries of the brain is not 
 distinct. This part of the anatomy of the arteries, deserves 
 particular consideration in pathology, and in performing opera- 
 tions. 
 
 409. The texture of the arteries* results from several su- 
 per-imposed membranous layers. There has been much di- 
 versity of opinion with reference to their number, it being sup- 
 posed to be, even as far as five by some anatomists, and re- 
 duced to one by others. It may be fixed at three, namely: 
 an outer, a middle, and an inner. 
 
 410. The external membrane, called also, cellular, ner- 
 vous, fibrous, &c. , is thin, and of a whitish colour, and formed 
 of oblique and crossed fibres, interlaced diagonally with refer- 
 ence to the length of the vessel. Externally this tissue is ra- 
 ther loose, and adheres to the sheath; internally, on the con- 
 trary, the little fibres are so close that they can only be per- 
 ceived on tearing them asunder. In the arterial trunks, this 
 two-fold disposition is so distinct, that the outer layer really 
 appears double; in the middle sized and small arteries, on the 
 contrary, this layer becomes uniformly close and distinct from 
 the cellular tissue of the sheath, and then greatly resembles 
 the ligamentous tissue. 
 
 This membrane is very tough and very elastic, both in its 
 longitudinal and circular direction. Supple and possessing 
 great strength at the same time, it is not divided by the action 
 of ligatures, even when directly applied to it. When we at- 
 tempt to tear it, great difficulty is experienced, and the texture 
 of its oblique fibres is perceived, which render its tenacity 
 equal in all directions. 
 
 411. The middle membrane, called also muscular, ten- 
 
 * Ludwig 1 , de Jlrteriarum titnicis, Lips. 1739. Albinus, acad. annot. lib. iv. 
 Cap. viii. de arterisR membranis et vasis. A. Monro, Remarks on the coats of 
 arteries, their diseases, &fc., in his works- Delasone, sur la structure des arte- 
 res, mtm. de Facad. des sci. 1756. C. Mondini, de JLrteriarum tunicis, in 
 opusculis sdeniifici t. i. Bologna, 1817. A. Beclard, sur les Blcssures des 
 cu'teries, Mt'm. de la sod. mcd. d 1 emulation, t. viii. Paris, 1817. 
 
OF THE ARTKRIES. 279 
 
 dinous, proper membrane, &c. is thick amKof a yellowish co- 
 lour, and is formed of nearly circular or annular fibres. This 
 membrane, the thickest of the three, is very apparent in the 
 trunks; it augments proportionally in thickness, as the arte- 
 ries diminish in volume. Its thickness is inconsiderable in 
 the arteries of certain viscera, and particularly in the arteries 
 of the brain. It can be divided into several layers by dissec- 
 tion; this, probably, has led into error those who have ad- 
 mitted more than three arterial membranes. The external 
 fibres are less close, the deeper seated still more so, and thus 
 progressively. These fibres do not all encircle the vessel. 
 The longitudinal and spiral fibres which have been admitted 
 in the middle membrane, do not exist. In the places where 
 the arteries divide, the circular fibres of the trunk separate 
 and form on each side a half ring, and the annular fibres of 
 the branches succeed these latter. The middle membrane is 
 intimately united to the outer one. 
 
 The middle membrane has so great a degree of strength, 
 that when detached from the others it retains its cylindrical 
 form; it is to it that the arteries owe the faculty of remaining 
 open when they are empty. When isolated, it possesses a 
 feeble power of resistance and elasticity, in the longitudinal 
 direction of the arteries, but is very tenacious and elastic in 
 the direction of its fibres, i. e. in that of the circumference of 
 the vessel. The firmness and elasticity of the fibres, which 
 form it, successively diminish from the large towards the 
 small arteries. It has been, by turns, compared and likened 
 to the muscular fibre in general, the muscular fibre of the 
 uterus, and the fibrous or ligamentous tissue; it constitutes a 
 species of elastic tissue, a peculiar tissue, but participating of 
 the characters of the muscular and ligamentous fibres. 
 
 412. The inner membrane of the arteries, which is also 
 named the nervous, arachnoid, common, &c. is the thinnest of 
 the three. It is continued from the ventricles of the heart 
 into the arteries; by it the greater part of the semi-lunar valves 
 of the arteries are formed. In the larger branches, when empty, 
 it presents some longitudinal folds, and small transverse ones 
 in the arteries of the ham and elbow-joint; it is equally wrin- 
 37 
 
280 GENERAL ANATOMY. 
 
 kled in the retracted arteries after amputation. Its inner sur- 
 face is smooth, polished, moist, and in contact with the blood; 
 its outer surface adheres to the middle membrane. In the 
 arterial trunk, it can be divided into several layers. The in- 
 nermost is extremely thin, and transparent; the others are of 
 an opaque white, and passes insensibly into the middle mem- 
 brane; it is to this part especially, that the name of nervous 
 membrane has been given. In the branches, it forms only a 
 single indivisible lamina. No appearance of fibres is distin- 
 guished in this membrane, which is very dense ; it tears nearly 
 with the same facility in all directions. It has little elasticity. 
 It has been compared to the serous membrane and the mucous 
 or cellular tissue. It is not vascular like the serous membrane 
 generally; and it is to the arachnoid membrane that it bears 
 the greatest resemblance. 
 
 413. Cellular tissue, vessels and nerves, also enter into 
 the composition of the arteries. 
 
 The cellular tissue which penetrates into the outer mem- 
 brane, and which unites it to the middle one, is sufficiently 
 apparent, but beyond this, it is so rare and compact, that its 
 existence has been doubted. However, when by dissection 
 the outer membrane, and the greater part of the thickness of 
 the middle one are removed from an artery, there spring from 
 the uncovered part fleshy granulations, as from the remainder 
 of the wound. 
 
 414. The arteries and veins of the arteries (vctsa artcria- 
 rum 9 ) are furnished by the neighbouring vessels, and become 
 very apparent in the outer membrane by injections, and even 
 sometimes without them, particularly in young subjects. They 
 have been traced to their entrance into the middle membrane, 
 but no farther. 
 
 What are called exhalent and absorbent vessels, or more 
 correctly the unknown passages of exhalation and inhalation, 
 are demonstrated iti the parietes of the arteries by the fact 
 itself, for in inflammation of the arteries an exhalation occurs 
 at their internal surface; and, in cases of ligatures, the internal 
 coagulum is absorbed. 
 
OF THE ARTERIES. 281 
 
 415. The nerves* of the arteries are derived from the spi- 
 nal marrow and the ganglia. The arteries of the organs of the 
 vegetative functions receive theirs from the ganglia, the others 
 from the spinal marrow. The nerves of the arteries form 
 around them a net-work analogous to those which the pneu- 
 mogastric nerves form around the resaphagus, and thus accom- 
 pany them into the interior of the organs. But, moreover, 
 some filaments terminate in the outer layer, and others reach 
 the middle membrane, on which they spread out into a very 
 delicate net-work. The former are soft and flat, the latter, 
 which are filiform and of extreme minuteness, have more con- 
 sistence, and pass through a shorter course. All the arteries 
 do not receive an' equal number of nerves; the pulmonary ar- 
 teries receive fewer than the aorta and its divisions. The 
 smaller the arteries are, the more abundant are the nerves. 
 The arteries of the brain are furnished with nerves only to 
 the place where they penetrate into the cerebral substance. 
 In old age, the nerves of the arteries, especially those of the 
 middle membrane, become less apparent. The great number 
 of nerves which are distributed to the arteries, shows that a 
 close connexion exists between the nervous system and the 
 circulatory apparatus, or between the nerves and the blood. 
 
 416. The most physical properties of the arteries are the 
 toughness of their tissue, its tenacity and elasticity. It is to .the 
 firmness of the middle membrane that they especially owe the 
 power of preserving a considerable part of their tubular form, 
 even when empty of blood. Their specific gravity is about 
 108. Their thickness, which is generally considerable, is a 
 little augmented when they are empty. It is also somewhat 
 greater on the convex side of the curvatures than on the oppo- 
 site side, being nearly in the proportion of 8 to 7. It increases 
 proportionally to the caliber of the arteries in the same degree 
 as the latter diminishes; it is not the same, however, in all the 
 arteries of the same diameter; thus the parietes of the arte- 
 ries of the brain are very thin, and those of the limbs are 
 thick. 
 
 * A. Wrisberg, loc. cil. Lucre, quadam nlserv. anaf. circa Ntrvos arfm'aa 
 adrnufcs ef comitantes. -Ito rum Jfg. Fruncof. ad Mnenum, 1810. 
 
GENERAL ANATOMY. 
 
 417. Clifton Wintringham has examined the tenacity of 
 the arteries and the resistance they oppose to rupture. I have 
 also made some experiments on this subject. These vessels 
 have a great power of resistance, which is, generally, in pro- 
 portion to their thickness. That of the aorta is superior to 
 that of the pulmonary artery. In the same degree as the ar- 
 teries diminish in size, their absolute tenacity diminishes, but 
 their relative thickness and softness increase, their extensi- 
 bility and relative resistance augment. The resistance is not, 
 however, the same in all the arteries of the same volume: that 
 of the iliac artery is greater than that of the carotid. The te- 
 nacity in the longitudinal direction is almost entirely owing 
 to the outer membrane. The circular resistance, which is 
 much stronger, is owing to the middle and outer layers. The 
 inner membrane has very little power of resistance in either 
 direction. 
 
 418. The most important physical property of the arte- 
 ries is their elasticity. If they be distended in the longitudi- 
 nal direction, they yield and elongate, to return suddenly to 
 their former state whenever the distention ceases. If they be 
 distended transversely, the}'' are less distensible and spring 
 back with greater force. If by injection or insufflation they 
 are distended to excess, they enlarge a little, elongate, and 
 when the effort ceases, they spring back upon themselves and 
 expel part of their contents. If they be bent, they return to 
 their former direction; if they be flattened by pressure, they 
 resume their cylindrical form. During life, they are in a 
 state of elastic tension, which, when they are divided, causes 
 the ends to retract. 
 
 The largest arteries possess a very distinct elasticity, but it 
 diminishes successively in the smaller ones. 
 
 419. The arteries are also susceptible of a slow extensibi- 
 lity and retractibility. When a principal artery is obliterated, 
 the collateral arteries, in replacing 'it in its functions, enlarge 
 and acquire, in a short time, a considerable volume; this en- 
 largement is of the same kind as ordinary growth, but is much 
 more rapid: the artery, on the contrary, which ceases to af- 
 
OF THE ARTERIES. 285 
 
 ford a passage to the blood, gradually shrinks, and ultimately 
 disappears more or less completely. 
 
 420. The vital properties of the arteries, like those of the 
 other parts, are relative both to their own nutrition and to 
 their action in the organism. The force of formation is mani- 
 fest in them by their accidental productions, and less in the 
 reparation of their lessions. Irritability is susceptible to a 
 certain degree; sensibility is much less obvious. 
 
 421. Arterial irritability,* called also tonicity, contractili- 
 ty, vital force of the arteries, power of contraction, or the 
 force by which the parietes of the arteries, during life, draw 
 towards its axis without even having distended, has been a 
 subject of great controversy among physiologists. 
 
 Haller, who admits that the middle coat of arteries is of a 
 muscular nature, confesses that his experiments have taught 
 him nothing positive on their contractility, and that these 
 vessels have not always given evidence of the effects produced 
 on them by chemical and mechanical stimulants. Bichat, 
 Nysten, and Magendie, have all denied the irritability of the 
 arteries. Bichat founds his opinion on the circumstance, that 
 mechanical irritation within or without the vessel does not 
 produce motion; if an artery be open lengthwise, its edges 
 do not curl; if it be separated from the body, it evinces no 
 mark of contractility; if it be dissected layer by layer, its 
 fibres are not perceived to palpitate ; if the finger be intro- 
 duced into an artery during life, it is not firmly grasped by it; if 
 an artery be intercepted between two ligatures, it experiences 
 only a motion communicated to it. The contraction produced 
 by acids, is a horny induration, and the action of alkalies is 
 next to nothing. 
 
 The greater number of anatomists and physiologists, how- 
 ever, are of a contrary opinion, founding it on a great number 
 of facts. Verschuir and Hastings have observed mechanical 
 
 * See Chr. Kramp, de vi vitali arteriarum. Argent, 1785. C. H. Parry, 
 An exper. inquiry info the, puke and oilier prop, of arteries, &c. Bath, 1816. 
 Oh. H. Parry, Additional experi. on the arteries, &c. Lond. 1819. Hast- 
 ings, be. cit. 
 
284 GENERAL ANATOMY. 
 
 irritation to produce the contraction of the arteries. Zi miner- 
 mann, Parry, Verschuir, and Hastings have remarked that mi- 
 neral and vegetable acids cause the same effect. Thomson and 
 Hastings have seen the same thing occur by the action of am- 
 monia. Verschuir, Hunter, and Hastings have observed the 
 simple action of the air and of temperature to produce this con- 
 traction. Hastings has also obtained the same result by the 
 application of oil of turpentine, the tincture of cantharides, the 
 solution of muriate of ammonia, and of sulphate of copper. 
 Bikker and Van den Bosch have caused the contraction of the 
 arteries by electricity; Guilo and Rossi by galvanism; Home 
 Jias observed it even on the application of an alkali on the 
 nerve adjoining an artery. Vital contractility, little apprecia- 
 ble in the larger arteries, augments successively in the smaller 
 .ones. 
 
 We may also cite as a farther proof of the existence of the 
 irritability .of the arteries, the augmentation of their contrac- 
 tion in inflammation and in neurosis. Thus, in panaris, in 
 angina tonsillaris, in tic douloureux, &c.; we see and feel the 
 arteries beat on one side much more than on the other. We 
 sometimes observe differences of the same kind in hemiplcgia. 
 The same thing also occurs in pregnancy, and in many other 
 hygid or morbid phenomena, accompanied with a local de- 
 velopment of vessels. 
 
 We may therefore conclude, from what proceeds, that during 
 life the arteries possess both elasticity and irritability; that 
 elasticity predominates in the large, and irritability in the small 
 arteries; that arterial irritability is more or less dependent upon 
 the nervous influence. In the course of time, the vasa vaso- 
 ntm diminishing, the nerves of the arteries gradually disap- 
 pearing, and the middle membrane becoming harder, the arte- 
 rial irritability lessens more and more, and even the elasticity 
 itself is greatly impaired. 
 
 422. The sensibility of the arteries is null or extremely 
 obscure. Verschuir relates one single experiment in which 
 an animal seemed to feel pain on the application of a mineral 
 acid. According to Bichat, on injecting an irritating liquid 
 a lively pain appears also to be produced. 
 
OF THE ARTERIES. 285 
 
 423. The function of the arteries is to convey the Wood 
 from the heart to all the parts of the bod}-. When the ventri- 
 cles of the heart propel, while contracting, a new supply of li- 
 quid into the arteries, already full with blood in motion, the 
 velocity of the motion is increased in all the arteries: the ob- 
 servation of the wound of an artery proves it. Another effect 
 of the systole of the ventricles, generally admitted, is the dila- 
 tation of the arteries. Experiments have been cited in sup- 
 port of this dilatation; other interesting experiments of Doctor 
 Parry appear to contradict it; it really exists, however, but it 
 is very inconsiderable. Another effect, but more appreciable, 
 produced by each systole, is the elongation of the arteries. 
 The action exercised by the arteries in order to send forward 
 the blood, is their elastic return on themselves, which narrows 
 and shortens them, and consequently diminishes their capacity, 
 and moreover, a force of vital contraction which is added to 
 elasticity in the middle sized arteries, and this vital contrac- 
 tion exists exclusively in the small. The velocity of the course 
 of the arterial blood generally diminishes from the trunks to 
 the last ramifications; this velocity presents besides local va- 
 rieties, either permanent or accidental. 
 
 The function of the arteries is therefore to convey, like ca- 
 nals, the blood in all the parts of the body, and like contrac- 
 tile canals, to communicate to it a part of the motion with 
 which it is animated. The action of the arteries on the blood 
 has been at times exaggerated and at others too little appre- 
 ciated. It is very certain, 1st, that the vessels appear before 
 the heart, both in the animal series and embryo; 2d, that the 
 monstrous foetus without a head is deprived of a heart; 3d, that 
 in fishes there is no aortic ventricle, and that even in man the 
 vena portarum (sect, iii.) is equally deprived of a muscular 
 agent calculated to communicate an impulsion; 4th, that in the 
 reptiles from which the heart has been removed, the motion 
 of the blood continues for a long time. All these facts evi- 
 dently prove that the vessels are an agent, and are even the 
 primitive agent of the motion of the blood. The arteries par- 
 ticipate in this movement by their elasticity and irritability. 
 
 But it is no less certain, that in animals provided with a 
 
286 GENERAL ANATOMY. 
 
 heart, this organ becomes a powerful agent of the movement 
 of the blood; it is thus, that by its own action the arterial cir- 
 culation, although continuous, is pulsatory; it is thus that the 
 circulation takes place in the sturgeon, although the aorta is 
 inclosed in a bony canal; in the same manner in man, the aorta 
 and its principal branches may be ossified without materially 
 impairing the regularity of the course of the blood. We must 
 hence conclude that both these powers (that of the heart and 
 that of the arteries,) contribute to the performance of the cir- 
 culation, and that one may in a measure supply the action of 
 the other. But the action of the heart on the blood gradually 
 diminishes, and that of the vessels augments, in proportion as 
 it is more distant from the centre of circulation. The vital 
 contraction of the arteries is also one of the causes of their 
 emptiness in the dead body.* 
 
 424. The arterial circulation is accompanied with a move- 
 ment called pulse. At different times it was ascribed to the 
 alternate dilatation and contraction of the arteries; to the elon- 
 gation of these vessels, and to the motion which results from 
 it; to the pressure of the finger while feeling it, or to several 
 of these causes combined. The number of pulsations de- 
 pend solely upon that of the contraction of the heart. The 
 volume or fullness of the pulse is owing to the quantity of the 
 blood contained in the arteries; its duration, to that of the con- 
 tractions of the heart; its strength, to the quantity of the blood 
 propelled by the heart, to the power with which it is pushed, 
 to the quantity contained in the arteries, and to that which 
 passes through the capillary vessels. 
 
 The feeling of the pulse has for its object the examination 
 of the state of the circulation, and of the powers which move 
 the blood, viz., the heart and vessels. 
 
 * With all due deference for the opinion of our author, we beg to differ 
 with him on this point. We believe that the new experiments on endos- 
 mose and exosmose tend to prove the contrary position. We conceive that 
 the larger arteries have lost at this time all power of vital contract here 
 ascribed to them, when the blood is, by an action in the capillaries, as y t 
 not positively demonstrated, drawn from the larger arteries through the ca- 
 pillaries into the veins. 
 
OF THE ARTERIES. 287 
 
 The parietes of the arteries augment in thickness and densi- 
 ty during the period of growth; they still continue to increase 
 in density during the remainder of life. 
 
 The variations in the distribution of the arteries arc much 
 more frequent than is generally imagined. Bichat and Meek- 
 el* have justly remarked, that they are at least as often met 
 with, as those of the veins, and perhaps even more frequently. 
 It is especially in the larger arteries that they are remarkable,! 
 both by their frequency, and by a sort of regularity or sym- 
 metry, and by the resemblance they then present with the 
 regular state of certain animals. 
 
 425. Besides the accidental vessels already indicated [371,] 
 when a principal artery is interrupted in its continuity, there 
 are established also other passages for the circulation. These 
 new passages are commonly formed out of the ancient small 
 vessels, but greatly enlarged, which were previously white, 
 by their extreme thinness, become red, or which, being red 
 and capillary, become more voluminous; but which, before 
 this circumstance, formed, by their anastomoses, collateral 
 passages [350]. In certain cases circulation is re-established 
 through passages entirely of a new formation. This fact, 
 the existence of which was suspected by J. Hunter, by Mau- 
 noir and even by Jones, although he controverted Maunoir's 
 opinion, has been put beyond question by the experiments 
 of Dr. Parry.J If the carotid artery of a sheep be tied, or 
 a part be removed, an artery which furnishes no branches in 
 the whole extent of the neck, we find some time after, the cir- 
 culation re-established in the very place where the artery has 
 been obliterated or cut off, by several branches nearly parallel, 
 occupying the interval which exists between the divided ex- 
 tremities of the artery. 
 
 426. The general inflammation of the arteries is of a rare 
 occurrence; their local inflammation is, on the contrary, often 
 met with. Simple redness, however, is not sufficient to charac- 
 terize it; there is, moreover, some thickening or softening in 
 
 * Deutschus archiv. fur die physiologic. 
 
 f Fr. Ticdemann, Tabula artcriarum corp. humani. Calsruhae, 1822. 
 
 * Loc. cit. 
 
 38 
 
288 GENERAL ANATOMY. 
 
 the parietes, and internally a plastic exudation, sometimes pus, 
 and at others more or less extensive ulcerations. 
 
 427. The wounds* of the arteries present anatomical con- 
 siderations of great importance. The puncture of an artery 
 gives rise to a feeble hemorrhage if the vessel be surrounded 
 by cellular tissue; but it is greater if it be deprived of its 
 sheath. The hemorrhage is arrested by the coagulation of the 
 blood, which is afterwards gradually absorbed; there is, during 
 a short time, a small enlargement opposite the puncture; after- 
 wards so very perfect a cicatrix is formed, that it is impossi- 
 ble to perceive it. A small incision, lengthwise with the 
 vessel, opens a little, and gives rise to a hemorrhage greater 
 than that produced by the puncture. The cure is sometimes 
 effectuated afterwards, and in the same manner. A transverse 
 incision produces, by the considerable separation of its edges, 
 a more or less serious hemorrhage, according to the extent 
 of the laceration of its cellular sheath. The hemorrhage is 
 the more serious, the more the incision involves, more than 
 one half of the circumference of the vessel, a case in which, if 
 left to itself, it continues or is renewed after being stopped, 
 until death takes place. In the cases in which the lesion reaches 
 only a small part of the circumference, if the sheath exists, 
 after having bled more or less, the blood infiltrates and coagu- 
 lates in it, and sometimes a cicatrix is formed, which, in man, 
 is much less solid than the original parietes of the artery, and 
 which becomes commonly the seat or the cause of a consecu- 
 tive aneurism. When, on the contrary, the transversal divi- 
 sion is much greater than one half of the circumference, the 
 retraction, as well as the diminution of its size, which result 
 from it, is such, that if the sheath still exists, the blood infil- 
 trates, stops, and coagulates in it, and the cure may also take 
 place. But in order that this may occur, the complete divi- 
 sion of the artery is accomplished, and then this case belongs 
 to the following. 
 
 428. Whenever an artery of a mean caliber is cut across, 
 
 * J. F. D. Jones, on the process employed by nature in suppressing hem- 
 orrhage, 6fc. Lond. 1810. Beclard, loc. cit. 
 
OP THE ARTERIES. 289 
 
 either on a surface, the result of an amputation, or in the con- 
 tinuation of the soft parts, the blood issues in a full stream and 
 by a constant jet, alternately rising and lowering until the 
 circulation is greatly enfeebled; then the bleeding diminishes 
 and stops, either to recommence one or more times when the 
 weakness has ceased, and to continue even to death, or ceases 
 altogether. In this latter case, very rare in the human species, 
 the artery being retracted in its sheath and in the surround- 
 ing cellular tissue, the blood infiltrates and coagulates around 
 the end of the vessel; it coagulates also in the end itself to a 
 greater or smaller distance, always determined, however, by 
 the situation of the nearest branch, through which the circu- 
 lation still continues to take place. The extremity of the arte- 
 ry is then obstructed and plugged, nearly in the same manner 
 as is the mouth of a bottle by the cork, and by the wax with 
 which it is covered. The artery being no longer influenced by 
 the alternate distention it previously experienced, gradually 
 shrinks; its divided extremity undergoes traumatic inflamma- 
 tion, and becomes the seat of a plastic exudation; the blood, 
 cogulated internally and externally, is gradually absorbed, the 
 artery cotinues to contract, it is converted into a mere cord, 
 and commonly disappears, or is changed into cellular tissue as 
 far as the neighbourhood of the nearest branch, which con- 
 tinues to carry on the circulation. 
 
 429. When an artery is distended lengthwise, it greatly 
 elongates at first by sliding in its sheath, favoured by the cellu- 
 lar tissue which surround it; after yielding a great deal with- 
 out breaking, it begins to tear internally. The external mem- 
 brane is the last part torn, after being elongated and thinned 
 nearly in the manner of a tube of glass melted and drawn over 
 a lamp. After being torn, the extremities of the artery re- 
 treat less than they have yielded, and the blood jets out, at 
 first, as in the preceding case; but ordinarily, it soon stops, 
 never to reappear. This quick and entire cessation of the 
 hemorrhage, which almost always occurs in similar cases, has 
 been ascribed to the retraction of the artery and to other ima- 
 ginary causes. I am convinced, by many experiments per- 
 formed on animals, and by many observations made on man, 
 
290 GENERAL ANATOMY. 
 
 that we ought to attribute this remarkable phenomenon, to the 
 more or less multiplied internal ruptures that the artery ex- 
 periences before its total division at any one point. The phe- 
 nomena which follow are the same as after the transversal 
 section. (428.) 
 
 430. A ligature applied to an artery, either when entire, 
 or when it is cut as at the surface of an amputated limb, suffi- 
 ciently tight to arrest the circulation in the vessel, cuts the in- 
 ner and middle membrane,and,if the artery is healthy, without, 
 divides the outer one. If the ligature is permitted to remain, 
 the blood stopped in the vessel coagulates in its cavity as far 
 as to the nearest branch. The division experienced by the in- 
 ner membranes, the pressure exercised on the external ones and 
 the presence of the ligature, induce an effusion of organizable 
 matter, which produces at first the agglutination of all the in- 
 jured parts; the part embraced within the ligature is at first 
 softened, is afterwards divided by the effect of inflammation, 
 and the ligature comes off. The changes which follow in the 
 vessel are the same as after the transverse section. (428.) 
 
 431. In the three kinds of wounds of which we have just 
 treated, (428, 430.) the ulterior phenomena are different, ac- 
 cording as they are made on an amputated surface or in the 
 continuity of the parts. In an amputated surface, the princi- 
 pal artery is not only obliterated, but also its branches termi- 
 nating at the surface, so that the trunk itself is more or less 
 narrowed. In the other case, on the contrary, the branches 
 which arise from the artery on which a ligature has been ap- 
 plied, divided or torn, not only continue to carry on the cir- 
 culation, but dilate in order to supply the principal trunk; 
 they thus keep up, even to the point where they arise, the 
 fluidity of the blood, its motion, and its influence on the vessel. 
 It is to this difference that must be ascribed the frequency of 
 the primitive reunion of divided arteries on an amputated sur- 
 face, and the comparative few cases of this happy result, when 
 the division of the artery happens in the soft parts. 
 
 432. We sometimes find a cartilaginous production or 
 transformation, with thickening of the parietes of the arteries, 
 commonly in a somewhat confined extent. Athcromatous, 
 
OP THE ARTERIES. 291 
 
 steatomatous productions, &c. are, like the preceding, only the 
 beginning of the calcarious ossification of which the arteries 
 are so often the seat. This ossification is of two kinds, acci- 
 dental and senile. The first has its seat between the inner and 
 middle membranes, and is preceded by one of the above men- 
 tioned alterations. The second, on the contrary, has its seat 
 in the middle membrane, and consists in a transformation of 
 its fibrous rings into osseous ones, more or less extensive. The 
 different parts of the arterial system are not every way equally 
 predisposed to it. The aortic system is oftener affected by it 
 than the pulmonary. The internal projections of the arteries, 
 and the valves of their trunks, are frequently the seat of this 
 affection; the aorta and its principal branches are often in the 
 same case; oftener in the arteries of the inferior members than 
 in those of the superior extremities; pretty often in those of 
 the muscles, heart, brain and spleen ; but rarely in those of the 
 stomach and liver. Finally, Harvey, Riolan, and Loder, have 
 observed the whole arterial system ossified. The ossification 
 of the arteries most generally occurs in old age; accidental os- 
 sification, however, is also sometimes observed in young sub- 
 jects, and in early infancy. This affection of the arteries is 
 not so frequent in woman as in man. It is much more com- 
 mon in cold than in warm climates. 
 
 The effect of arterial ossification, and especially of that which 
 is accidental, is to produce the wearing of the membranes be- 
 tween which it is placed. The ossification of the arteries has 
 been ascribed to a great many causes. The accidental one is 
 a true production or deposition; that which is senile seems to 
 be the. last conditions of the successive changes that the middle 
 membrane experiences during life, but in the first period of 
 which is soft and red. 
 
 433. Excrescences of a fleshy consistence are sometimes 
 found attached to the internal surface of arteries, and espe- 
 cially to the semi-lunar valves which are at their entrance. 
 
 434. The dilatation of the arteries is a very common affec- 
 tion; it may consist: 1st, in a simple loss of elasticity without 
 any apparent alteration of the parietes; 2d, in an alteration of 
 the dilated parietes. 
 
292 GENERAL ANATOMY. 
 
 Simple dilatation is especially met with in the large trunks; 
 it affects equally the whole circumference, and the tumour 
 resulting from it has an ovoid form. It has often been ob- 
 served in the aorta, particularly at its curvature, and some- 
 times in the pulmonary artery. 
 
 The dilatation, with an alteration of the parietes, affects the 
 aorta and the different parts of the aortic system even to the 
 ramifications. The arteries of the superior members are more 
 seldom affected than those of the inferior. The alteration and 
 dilatation which results from it, are most commonly lateral. 
 This is the affection that authors have described, since Fernel, 
 under the name of true aneurism. The altered parietes are 
 rather thickened than thinned in it. The blood contained in 
 these two kinds of dilatations is fluid. 
 
 435. Aneurism is caused by the injury or rupture, in a 
 word, by the solution of continuity of the arterial parietes, 
 commonly preceded by the dilatation of these parietes, and 
 always preceded by their alteration. It consists in a cavity 
 formed by the outer membrane, dilated and strengthened on 
 all sides by the cellular tissue and by the other surrounding 
 parts ; lined internally by a thin and in some places polished 
 membrane, resembling very much the inner membrane of 
 arteries. This cavity communicates with that of the vessel, 
 through a passage sometimes regular, at others irregular, made 
 in the inner and middle membranes; it is filled with coagu- 
 lated blood, and with layers of fibrine more or less firm, dif- 
 ferently altered, and perhaps mixed with organizable matter 
 produced by the parietes of the cavity. The blood, in its cir- 
 culatory course, penetrates continually into the accidental 
 cavity. 
 
 Sometimes aneurisms enlarge indefinitely, and cause death 
 by the compression they produce on the neighbouring organs 
 and by the disturbance of their functions. At others it is 
 ruptured either externally or internally, and causes death by 
 hemorrhage or by effusion. At other times it inflames, sup- 
 purates and opens like a large abscess, and then sometimes 
 hemorrhage occurs, or, on the contrary, the artery being ob- 
 literated by inflammation, a radical cure may follow. Some- 
 
OP THE VEINS. 293 
 
 times inflammation terminates in the gangrene of the tumour, 
 and either of the effects here above mentioned may be the 
 result of the separation of the eschar. Finally, at other times, 
 the circulation imperceptibly diminishes in the artery affected 
 with aneurism, and becomes at the same time more and more 
 active in the collateral passages or vessels, from which finally 
 result the obliteration of the affected artery as far as the neigh- 
 bouring branches of the tumour, and the gradual absorption 
 of the latter. 
 
 436. Arteries, inflamed or affected with an accidental 
 production in their parietes, or without any apparent cause, 
 instead of dilating and tearing, are sometimes narrowed, and 
 even are obliterated spontaneously. Thus the aorta has been 
 observed narrowed and even altogether obliterated; the total 
 obliteration of the right pulmonary artery has also been re- 
 marked. I have seen once that of the carotid artery, several 
 times the narrowing of the caliber of the brachial trunk, and 
 often the narrowing and obliteration of the crural trunk and 
 of its branches. This is the ordinary cause of senile gangrene 
 of the toes, feet and legs; this change occurring in a part and 
 at a time in which the arterial branches, they themselves 
 being affected with hardening, are no longer susceptible of 
 rapid growth, necessary to the re-establishment of the colla- 
 teral circulation. 
 
 SECTION III. 
 
 OP THE VEINS. 
 
 437. The veins* are the vessels which bring back to the 
 heart the blood from every part of the body. 
 
 438. We have already seen that the ancients have at first 
 made no distinction between the veins and arteries. Galen, 
 
 * Diatribe anatomico-physiobgica de strudura atque vita venarum, Au- 
 tore H. Marx, in 8vo. Carlsruhze, 1819. 
 
294 GENERAL ANATOMY. 
 
 who distinguished them very well, placed the origin of the 
 former in the liver. The difference and connexion between 
 the arteries and veins have been perfectly established by the 
 discovery of the circulation of the blood ; since that time, the 
 study of the venous system has been somewhat neglected.* 
 
 439. The veins, like all the vascular system, have an ar- 
 borescent disposition ; but considered with respect to the di- 
 rection of the course of the blood, they rather resemble the 
 roots of a tree, than its branches. Thus their origin takes 
 place by radicles, which correspond to the ramuscules of the 
 arteries; their termination by trunks which open into the 
 heart, like the origin of the arteries; their course presents re- 
 unions and successive divisions, like that of the arteries. If 
 examined then, by following the course of the blood, they 
 present a contrary disposition to that of the arteries; and if 
 considered in the same direction as the arteries, we should 
 follow a course opposite to that of the blood. 
 
 440. The venous system, like the arterial, is double; the 
 one general, returns the blood of the body to the anterior or 
 right auricle; the other brings back the blood from the lungs 
 to the other auricle of the heart. There is moreover a parti- 
 cular and complicated venous system in the abdomen: this is 
 the vena porta, the disposition of which must be the object of 
 a separate investigation. 
 
 441. This particular venous system constitutes of itself a 
 whole vascular system, that is to say, a tree having a trunk, 
 roots and branches, placed between the last ramuscules of the 
 gastric, intestinal and splenic arteries, which are continuous 
 with its roots, and the first radicles of the sub-hepatic veins, 
 which are the continuation of its branches. This vascular 
 system, if we take into consideration its disposition, which is 
 ramified in opposite directions, resembles the veins in its in- 
 testinal half, and the arteries in its hepatic half; under another 
 relation, it is indifferent to both, being intermediate, for it is 
 at the point where it is the continuation of the arteries, that it 
 has the venous disposition and vice versa. This vascular 
 
 * Since our author wrote this passage, M. Breschet is publishing a most 
 splendid work on the venous system; which see. TRANS. 
 
OP THE VEINS. 295 
 
 system is comprehended in the general venous system, espe- 
 cially on account of the nature of the blood it contains. 
 
 442. In the vertebrated oviparous animals another venous 
 system, analogous to the intestino-hepatic vessels, is found. 
 This particular system* is formed by the union of the veins 
 of the middle region of the body only, or of this region and 
 of the tail, which veins terminate in the kidneys in the same 
 manner as the arteries, sending sometimes a branch to the 
 vena porta, that is lo say, to the liver. I have sometimes ob- 
 served, in the dog, the vena porta to have one or two renal 
 terminations. 
 
 443. The number of veins is in general greater than that 
 of the arteries. There are two venae cavae, and one cardiac 
 vein to correspond with the single trunk of the aorta. There 
 are, in the same manner, four pulmonary veins to correspond 
 with the single pulmonary artery and its two branches. But 
 each of these venous divisions corresponds with a branch of a 
 corresponding artery. In almost the whole extent of the body, 
 there are many more subcutaneous veins than arteries, and in 
 deep seated parts, there are almost every where two venae 
 committes for a single artery. In the stomach, the spleen, the 
 kidneys, the testicles, the ovaries, and some other parts, the 
 number of veins is equal to that of the arteries. In some 
 parts, the number of veins is even less than that of the arte- 
 ries, as for instance, in the umbilical cord, in the penis, in the 
 clitoris, in the gall-bladder, surrenal capsules, &c. But this 
 is compensated by the difference of capacity. The size of the 
 veins generally, is in fact more considerable than that of cor- 
 responding arteries. 
 
 The sum of the veins, or their total capacity, is then greater 
 than that of the arteries. Many calculations have been made 
 respecting it; but we can only say with Haller, that the veins 
 are at the least double of the arteries in capacity. But, indepen- 
 dently of individual, accidental, or temporary differences, and 
 those which depend upon the kind of death, it continually 
 
 * Lud. Jacobson, de systematc venoso peculiuri in pcrmultis animalibus 
 vbservato. Hafnije, 1821. 
 39 
 
296 GENERAL ANATOMY. 
 
 varies with age. This difference, moreover", is not the same 
 in all parts of the body. In the pulmonary system it does 
 not exist, for the veins are there apparently equal in capacity 
 to the arteries. This is also the case with the renal vessels. 
 In the testicles, on the contrary, the veins are greatly superior 
 to the arteries. 
 
 444. The situation of the veins is generally the same as 
 that of the arteries, these two kinds of vessels accompanying 
 each other in their course, and uniting at their termination. 
 Almost every where, a trunk, a branch, or a twig of an artery, 
 is accompanied by one or two veins. There are, however, 
 exceptions: thus, in the cranium, the spine, the eye and liver, 
 the arteries and veins affect different situations and disposi- 
 tions; the vena azygos, the trunk of the intercostal veins in 
 the space between the pericardium and liver, is not accompa- 
 nied by an artery, and this is also the case with the subcutane- 
 ous veins. 
 
 445. The veins commence by capillary or microscopic 
 radicles, forming a continuation of the ramuscules of the arte- 
 ries. These radicles are colourless or red, according as their 
 diameter admits a single series of globules, or several at once. 
 In some places, as in the intestine, the lungs, &c., the succes- 
 sive reunion of the radicles of the veins corresponding with, 
 and entirely similar to the divisions of the arterial ramuscules. 
 In other places the disposition is different. Without speaking 
 of the erectile or cavernous tissue, in which the swelling and 
 communication of the veins are extreme, in many other parts 
 they have different dispositions from those of the arteries: 
 they form plexuses at the neck of the bladder, in the spine, 
 and around the spermatic artery, wide canals in the spongy 
 bones, and under the skin, they form, by their numerous com- 
 munications, a great vascular net-work with angular, and most 
 ordinarily meshes. 
 
 They are not so regularly cylindrical as the arteries, and so 
 far from following a regular order of increase in the volume 
 of the trunks and of decrease in their total capacity, very 
 large branches are sometimes seen connected with a trunk of 
 no great size, which depends especially on the softness of the 
 
OF THE VEINS. 297 
 
 parietes and the great number of anastomoses. The commu- 
 nication of the veins present all the varieties already indi- 
 cated [356,] and moreover, the union of the very large trunks, 
 as that of the venae cavae by the vena azygos; the union of su- 
 perficial and deep seated veins, as that of the cranial and spinal 
 veins with the epicranial, temporal, cervical, &e., that of the 
 internal and external jugular veins, and that of deep seated 
 veins, with the subcutaneous veins of the limbs. 
 
 Generally, the veins have a less flexuous, straighter, and 
 therefore, shorter course than the arteries. 
 
 The variations of the veins have been a little exaggerated, 
 and those of the arteries have been somewhat concealed. The 
 large venous trunks especially are less variable than they 
 have been announced; but the branches and twigs are very 
 much so. 
 
 446. The interior of the veins present a great number of 
 valves* or folds of the inner membrane, which constitute a 
 great difference between them and the arteries. The valves 
 are very well seen by examining under water a vein split open 
 lengthwise. 
 
 Each valve consists in a fold of the inner membrane. This 
 fold has a convex edge, adhering to the parietes of the vein 
 on the side towards its radicles, and a concave and free mar- 
 gin, turned towards the heart. These two edges are some- 
 what thicker than the rest of the fold; one of the surfaces 
 is turned towards the cavity of the vessel, and corresponds 
 to the circulating blood, the other corresponds to the parietes 
 of the vein, somewhat dilated at this point. When the valve 
 shuts, the surface, which corresponds to the radicles, becomes 
 convex, the other becomes concave, and the vein slightly en- 
 larges; the valves are so much the more broad as the vein is 
 the more voluminous, and so much the more elongated as it 
 is smaller. It is to this difference especially that the varieties 
 of form described by Perrault and several others is to be re- 
 ferred. 
 
 * H. Fabricio, de venarum ostiolis, in op. omn.J. G. Schmiedt and Mei- 
 bomius, de valvulls seu membranulis vasorum earumque struct, et usu, Helmst 
 1682. Perrault Essais de physique, torn. iii. 
 
GENERAL ANATOMY. 
 
 Besides the inner membrane, there exists also in the sub- 
 stance of the valves, dense cellular tissue, and sometimes dis- 
 tinct fibres; sometimes they are areolar and perforated like 
 lace. In the veins or sinuses of the dura mater, there occur 
 only some transverse fibres, which may be considered as ru- 
 dimentary valves. 
 
 The valves are generally disposed in pairs placed alternative- 
 ly, according to two opposite diameters of the vein. 
 
 They are three, and three in the great veins, as in the crural 
 and iliac; they are seldom observed quadruple, and very sel- 
 dom or never quintuple. In twigs, with a diameter of half a 
 line and less, they are single. 
 
 There are by no means valves at all the places where a twig 
 unites to a branch, or where a branch opens into a trunk; nor 
 are they everywhere at the same distance; they are nowhere 
 closer to each other than in the smallest veins. Valves are 
 found in the veins of the extremities, more in the subcutane- 
 ous than in the deep seated ones, in those of the face, neck, 
 tongue and tonsils, at the termination of the cardiac vein, in 
 the tegumentary veins of the abdomen, in those of the testi- 
 cles, penis and clitoris, in the internal and external iliac veins, 
 sometimes in the renal veins, and rarely in the vena azygos. 
 
 There are none in the encephalic, spinal and diploic veins, 
 in those of the lungs, in the vena porta, in the umbilical vein, 
 in the vense cavaB, if we except those at the entrance of the 
 vena azygos, in the uterine veins, and in the median vein. 
 
 There are generally a great many valves in the superficial 
 veins, fewer in the deep seated or intermuscular veins, and 
 still fewer in the veins of the splanchnic cavities; they are 
 numerous in the most depending parts, and therefore in the 
 lower extremities, less so in the upper, and still less numer- 
 ous in the head and neck. 
 
 The valves are applied against the parietes of the veins, 
 when the course of the blood is free and easy, but when it 
 meets with obstacles in its passage, the valves separate from 
 the walls, close the vein, sustain the blood, and prevent its 
 reflux towards the capillary vessels. 
 
OP THE VEINS. 299 
 
 447. The veins, like all the vessels, are surrounded by the 
 cellular tissue of the parts in which they are situated, which 
 forms a sheath, loose around the trunks, but more intimately 
 united with the twigs. The sheath of the vena porta is re- 
 markable in the liver, where it is known under the name of 
 capsule of Glisson. 
 
 The outer membrane, properly so called, is thinner and less 
 condensed than that of the arteries, to which it bears a great re- 
 semblance. The inner membrane is formed of fibres more ex- 
 tensible and softer than those of the arteries. These fibres appear 
 nearly all longitudinal, when the membrane is examined and 
 held between the eye and the light; some of the most inter- 
 nal fibres seem annular; but when we wish to separate the 
 fibres of this membrane, the same difficulty is experienced in 
 all directions. In the human species this membrane is much 
 thicker in the system of the inferior vena cava than in the 
 other; generally it is also thicker in the superficial than in 
 the deep seated veins; thus the internal saphenavein has very 
 thick parietes at the lower part of the leg. Near their en- 
 trance into the heart, the veins have distinct muscular fibres. 
 The inner membrane, which is thin and transparent, differs 
 from that of the arteries by its extensibility and its resistance 
 to rupture, and by its filamentous texture, which becomes evi- 
 dent when it is distended and torn. The large veins of the 
 cranium or sinuses, the veins of the bones and some others, 
 are almost entirely constituted by the inner membrane, and 
 are besides, as it were, scooped out in the substance of the dura 
 mater, the bones, &c. 
 
 The parietes of the veins are provided with small blood 
 vessels and nervous filaments, which may be followed for a 
 certain extent. 
 
 448. The parietes of the veins are whitish, semi-transpa- 
 rent, thinner than those of the arteries; generally their thick- 
 ness augments absolutely from the roots towards the trunks, 
 and diminishes, when compared with the diameter, by follow- 
 ing the same course. Their density is of 115 or 110; the 
 firmness of their walls is much less than that of the arteries, 
 for this reason they collapse when empty, with the exception 
 
300 GENERAL ANATOMY. 
 
 of those of the uterus, the liver, &c. which are attached to the 
 suhstance of the organs. They are less extensible in the lon- 
 gitudinal direction than the arteries, but much more so in the 
 circular. Since Wintringham's experiments, it is generally 
 admitted that the veins oppose a much greater force to the 
 causes of rupture than the arteries; on the other hand, they 
 not only yield much more to distention, but also tear across, 
 much more frequently than the arteries, while, on the con- 
 trary, they have appeared to me to resist greater distention 
 longitudinally. The parietes of the veins are very elastic, 
 but less so than those of the arteries. Their irritability or 
 vital contractility is, on the contrary, greater than that of the 
 arteries, but less than that of the capillaries. It has been de- 
 nied by several physiologists, but proved by many experi- 
 ments. It is sufficient to have observed the effect of local 
 cold on the subcutaneous veins, and to know that the portion 
 of a vein between two ligatures, when punctured, empties it- 
 self entirely and rapidly in a living animal, while this does 
 not occur after death, to admit the existence of irritability in 
 the veins. Their sensibility is obscure or doubtful; Monro, 
 in his lectures, affirmed that he had felt the puncture of a de- 
 nuded vein. The force of formation of the veins is not less 
 evident than that of the arteries. 
 
 449. The function of the veins is to convey the blood 
 from every part of the body to the heart. We have seen that 
 each contraction of the ventricles determines an augmentation 
 of the continuous movement of the blood in the arteries; this 
 augmentation goes on diminishing in the same degree as the 
 vessels become capillary. In these latter, as well as in the 
 veins generally, the movement is uniform. The blood in the 
 veins is animated by the movement imparted to it by the 
 heart, the arteries, and by the capillary vessels. Do the veins 
 exercise an additional action? This is not doubtful; let any 
 one compress or tie the artery of a member in an animal, the 
 flow of the blood in the veins will be slower; but will not be 
 for this stopped; if a vein be tied, it will however empty itself 
 above the ligature, it empties itself even between two liga- 
 tures. To the causes already mentioned, we must add the 
 
OF THE VEINS. 301 
 
 alternate relaxation of the heart, which produces a kind of at- 
 traction; inspiration, which produces a still more powerful 
 one, and the compression of the surrounding muscles. The 
 valves, by dividing the column of the blood, render these di- 
 verse powers more efficacious. The form of the venous sys- 
 tem is the cause that the movement of the blood, instead of 
 gradually diminishing, as in the arteries, is, indeed, slower 
 than these latter, the capacity of which is less than that of the 
 veins, but however, go on accelerating as it approaches the 
 heart. The venous circulation is much more dependent than 
 the arterial on the effects of gravity and pressure. 
 
 450. The course of the blood in the veins is continuous, 
 and these vessels do not present any pulsations; in some 
 places and under certain circumstances, however, they present 
 something analogous to an arterial pulse, which for this reason 
 is called venous pulse. In the neighbourhood of the heart, 
 the venous trunks, which are deprived of valves, experience 
 alternately, during the contraction of the auricles, a reflux of 
 blood which makes them swell out, and during the relaxation 
 of the auricles there occurs a rapid flux, which causes the veins 
 to be depressed. In the ordinary and regular state of func- 
 tions, this double movement is confined to the vicinity of the 
 heart and is not sensible; but when the circulation is em- 
 harassed it extends into the abdomen, and becomes visible in 
 the neck. It is the same with the influence of the motions of 
 respiration: inspiration accelerates the entrance of the blood 
 into the venae cavae and their auricle; active expiration, dif- 
 ficulty or suspension of respiration, and efforts, on the contra- 
 ry, slacken or suspend it; in the ordinary state, these effects are 
 little appreciable or extended; but they become very much 
 so in the opposite cases. The efforts, in which the effects of 
 active expiration are carried to the highest degree, determine, 
 in a very sensible manner, the stasis of the venous blood in the 
 head, the abdomen, and gradually even as far as the limbs; 
 while it is to the contrary effects of inspiration on venous cir- 
 culation, that we must ascribe death by the introduction of air 
 into the heart. When, in fact, by an operation or accident, a 
 large vein is opened at the base of the neck or in the subcla- 
 
3t)2 GENERAL ANATOMY. 
 
 vian region, a deep inspiration sometimes draws air into it, 
 which is sucked into the right cavity of the heart, and which, 
 by stopping the circulation, produces sudden death. 
 
 451. In youth the venous system is less extensive, in pro- 
 portion to the arterial system, than in the adult age; its rela- 
 tive capacity continues to augment in old age. The parietes 
 of the veins offer small observable changes; their senile ossi- 
 fication is extremely rare. 
 
 452. The morbid alterations of the veins,* have been less 
 studied than those of the arteries. 
 
 The inflammation of the veins or phlebites, is an affection 
 to which Hunter has been one of the first to draw the atten- 
 tion of the profession. It ordinarily occupies a considerable 
 extent of the veins, and generally extends towards the heart. 
 It often gives rise to the formation of pus, and at other times 
 to that of plastic matter in the cavity of the vein, around it, 
 and even in its own thickness. It mostly depends on mecha- 
 nical lesions. 
 
 453. Wounds of the veins, considered under an anatomical 
 point of view, present some analogy with those of the arteries; 
 but, in whatever mode they are inflicted, they are much more 
 easily followed by ulceration or extension and often suppura- 
 tive inflammation than those of the arteries, and they unite 
 with more difficulty. After puncture or incision, there re- 
 mains between the edges a space filled by a new membrane; 
 the ligature does not first determine the division of the inner 
 membrane and quickly its adhesion, but this membrane is at 
 first only plaited, and is divided but slowly in order to unite 
 feebly. 
 
 454. Accidental productions are more rare in the parietes 
 of the veins than in those of the arteries. The cartilaginous, 
 or an analogous thickening, occurs however sometimes in the 
 parietes of the veins which are obliterated; Morgagni ob- 
 served it once in the vena cava. Ossification is extremely 
 rare in the veins. Dr. Baillie has seen it once to occur in the 
 vena cava inferior near the iliacs, and Dr. Macartney once 
 
 * Hodgson* op. cit. B. Travers, Surgical Essays, part first. 
 
OF THE VEINS. 303 
 
 in the external vena snphena of a man who died with an ulcer 
 on the leg. I have observed that the parietes of the veins are 
 thicker on the side which touches an artery, than in the re- 
 mainder of their circumference, and I have once seen in an 
 old man a femoral vein ossified on the side next to the artery, 
 which itself was ossified throughout its circumference and for 
 some extent of its length. 
 
 Morbid productions are sometimes observed under the form 
 of vegetation, at the internal surface of the veins, whether 
 the affected vein be surrounded by similar productions, or 
 not. 
 
 455. The dilatation of the veins is very frequent, and is 
 of various kinds; sometimes the whole venous system is af- 
 fected by it; very often dilatation affects one or some veins 
 only, which constitutes varix. Almost every part of the body 
 may be the seat of it ; however, the most depending parts are 
 those most subject to it, as the inferior limbs, the genital or- 
 gans and the anus; it is also the most superficial veins, as the 
 subcutaneous, which are oftener affected. The augmentation 
 of the volume is not only in the circular dimension, but vari- 
 cose veins form a great many flexuosities which are ascribable 
 to the increase of their length. Sometimes dilatations of very 
 little extent, and confined to a part of the circumference of 
 the vein are found, either alone, or together with more gene- 
 ral dilatations. Varicose aneurism is another kind of dilata- 
 tion depending on the accidental communication of an artery 
 and a vein, and on the passage of the blood from the former 
 into the latter. This affection is commonly accompanied with 
 a remarkable thickening of the parietes of the elongated and 
 dilated vein. Moreover a consecutive aneurism is sometimes 
 formed between the two vessels: this case constitutes the va- 
 ricose aneurism. 
 
 456. Veins become sometimes narrow in consequence of 
 the thickening of their parietes; they are sometimes closed by 
 the effect of plastic inflammation; sometimes they are com- 
 pressed by neighbouring tumours, or embraced within a liga- 
 ture. In those cases, in which their cavity is obliterated, 
 
 and in which circulation no longer occurs, the blood passes 
 40 
 
304 GENERAL ANATOMY. 
 
 through branches and anastomoses, and a collateral circulation 
 is established. 
 
 The inferior vena cava has been found obliterated, either 
 under, or even on a level with the subhepatic veins, and the 
 blood passing through the vena azygos; one of the primitive 
 iliac veins, one of the jugular veins, &c. have been several 
 times found obliterated. Four times I have seen the trunk of 
 the crural vein obliterated in the groin, and in every instance 
 the circulation was easily carried on by collateral passages. 
 Hunter once observed the superior vena cava and the left 
 bracio-cephalic vein almost entirely destroyed by the pressure 
 caused by an aneurism. I have seen a case, however, in which 
 the superior vena cava and its branches were filled with 
 plastic matter, and impermeable to blood, and in which death 
 appeared to have been the result of this alteration. I have 
 remarked several times, but not always, great serous infiltra- 
 tions coinciding with the obliteration of the veins. 
 
 457. Small, hard and round bodies are sometimes found 
 in the veins, which on a superficial observation might be taken 
 for accidental osseous productions. Some writers have even 
 supposed that they were at first formed in the parietes of the 
 veins, in the edge of their valves, or even on the exterior of 
 these vessels; but this is not true. They are concretions, phle- 
 bolites, from the size of a grain of millet to that of a pea, of 
 various consistence, formed of superincumbent layers, inclosed 
 in the coagulated fibrinous blood, and often lodged in the lateral 
 dilatations of the veins where the blood stagnates, or in the 
 varicose veins, and always in the depending veins. The veins 
 in which they are, in fact, most commonly met with, are those 
 of the anus, the neck of the bladder, the uterus, the ovaries, 
 the testicles, and sometimes even the subcutaneous veins of 
 the leg. 
 
 The hexathyridium or polystoma venarum of which 
 Treutler found two in the ruptured tibial vein of a man, who 
 had been washing in a river, seems to be an aquatic worm, a 
 planaria, which had found its way in it, and not an (ento- 
 zoaire) cntozoary. 
 
OF THE LYMPHATIC VESSELS. 
 
 SECTION IV. 
 
 OF THE LYMPHATIC SYSTEM. 
 
 458. The lymphatic system comprehends, 1st: the vessels 
 which convey the lymph and chyle into the veins, and 2d 
 enlargements occurring in their course, and which are called 
 conglobate glands, or lymphatic ganglia. 
 
 ARTICLE I. 
 
 OF THE LYMPHATIC VESSELS. 
 
 459. The lymphatic vessels, called also absorbents, are so 
 attenuated, thin and valvular, which renders their observa- 
 tion and injection very difficult, that the knowledge of their 
 existence is rather of a recent date. The ancients, however, 
 had a glimspe of them. Erasistratus and Erophilus had cer- 
 tainly perceived the chyliferous vessels. It is Eustachio who 
 has discovered the thoracic canal in the horse. Aselli saw 
 and called lacteal vessels, the chyliferous vessels of some ani- 
 mals. He points out very well their functions. Veslingius 
 is the first who saw the chyliferous or lymphatic vessel of 
 the mesentery and thoracic duct in man. We owe to 0. Rud- 
 beck the discovery of the vessels of this kind in the other 
 parts of the body, although it has also been ascribed to Th. 
 Bartholin and to Jolyf. The discoverer gave them the name 
 of serous, aqueous, or lymphatic vessels. Bartholin conjec- 
 tured that they were, like the veins, continuous with the ca- 
 pillary arteries, and destined to convey the watery part of the 
 blood. Ruysch has very well described their valves. The 
 knowledge of the lymphatic vessels has been very much in- 
 creased by the labours of Meckel, Monro, by those of W. 
 Hunter, and of three of his disciples,!. Hunter, W. Hewson,* 
 
 * Descriptio systematis lyrnphatici, ex anglico versa, in op. omn. Lugd- 
 Bat 1795. 
 
306 GENERAL ANATOMY. 
 
 and Cruikshank;* especially by those of the illustrious P. 
 Mascagni,t and by some other writers, J all of whom have 
 ascribed to them patulous orifices, and absorption to these 
 orifices. 
 
 460. These vessels are commonly distinguished into chy- 
 liferous and lymphatic vessels; but this distinction is entirely 
 superfluous and without any utility, for their disposition, their 
 texture and their functions are the same. 
 
 461. The lymphatic vessels have an arborescent disposi- 
 tion, like other vessels. The humours which they contain, 
 pass through them, like the veins, from the ramifications, or 
 rather from the roots, towards the trunks. The aggregate of 
 these vessels consists in a principal and an accessory trunk, 
 in which numberless roots terminate. 
 
 462. Lymphatic vessels are found in every part of the 
 body, excepting the spinal marrow, the brain, the eye and the 
 placenta. 
 
 Their situation is remarkable, that in the limbs and in the 
 parietes of the trunk, they are, like the veins, distributed in 
 two plans, the one superficial or subcutaneous, the other in- 
 termuscular or deep, which accompanies the blood-vessels and 
 nerves; and that in the splanchnic cavities there occurs, also, 
 a plane of lymphatic vessels, situated immediately under the 
 serous membranes, and others more deeply seated. 
 
 463. The number of lymphatic vessels is very considera- 
 ble; as many as twenty are counted in the superficial plane of 
 the inferior limbs accompanying the inner saphena vein alone, 
 and a smaller, but still considerable number, accompanies the 
 deep seated vessels. The superficial lymphatic vessels are 
 
 * Anatomic dcs veisseaux absorbans da corps humain, traduite de 1'anglais 
 par Petit Radel. Paris, 1787. 
 
 j- Vasorum lymphaticorum corp. hum. historic, d ichonographia. Senis, 
 1787. 
 
 ^Luchvig, a German translation of Cruikshank and ofMuscagnf, with ad- 
 ditions. Lips. 1789. Werner and Feller, Vasorum ladeorum aiquc lymph, 
 anal, physiol. descriptio. Lips. 1784. J. G. Haase, dc vasis cutis et inteslin. 
 aljsnrbcnlibus, &c. Lips. 1786. Schrcger, FragntciUa ana. et physiol. 
 fane. i. Lips. 1791. 
 
OF THE LYMPHATIC VESSELS. 307 
 
 Jess voluminous than the deeply seated ones. The size of 
 these vessels is much less than that of the veins. Those of 
 the inferior extremities are larger than those of the superior 
 members, those of the head are very small. As to their ag- 
 gregate capacity, it has not been accurately determined; it 
 appears generally to be nearly double that of the arteries, and 
 to equal that of the veins in the superficial plane at least. 
 
 464. The origin of the lymphatic vessels is invisible and un- 
 known. Physiological considerations and anatomical experi- 
 ments have caused authors first to admit and then to reject their 
 direct and immediate continuation with the arteries. We have 
 also seen that the origin admitted to take place by open orifices 
 at the surface of the two tegumentary and serous membranes, 
 in the areolae of the cellular tissue, and in the substance of the 
 organs, which has been deduced from considerations and ex- 
 periments of the same kind, is not better founded. It is well 
 to know how to doubt. 
 
 465. As soon as they can be perceived, the radicles of the 
 lymphatic vessels are seen to unite together, to separate, and 
 unite anew, so as to form net-works which constitute in a 
 great measure the serous, tegumentary and other membranes. 
 
 These vessels become generally larger and more numerous 
 as they are farther removed from their origin. In their course 
 they continue to divide into branches, which reunite with 
 other neighbouring branches, or even with each other, so as 
 to form parts entirely surrounded by liquid. These divisions 
 and these numerous anastomoses form plexuses in many 
 places. 
 
 When they are full and a little distended they appear rather 
 moniliform than cylindrical. This appearance of a rosary is 
 owing to the great number of valves with which they are pro- 
 vided, and to the dilatation which they present above them. 
 They also frequently present ovoid dilatations. We observe 
 in them many variations in their course: those of one side al- 
 ways differ more or less from those of the other. 
 
 All the lymphatic vessels, after a longer or shorter course, 
 ramify in the same manner as the arteries, and seem to ter- 
 minate in lymphatic glands, beyond which they reappear again 
 
308 GENERAL ANATOMY. 
 
 formed of roots, which collect themselves in the manner of 
 veins. In those of the members, for the distance of several 
 feet, there are no interruptions of this kind; in those of the 
 mesenteiy, every few lines there are glands. Some pass along 
 side of a gland without entering it. It would even appear, 
 according to Cruikshank, that the lymphatic vessels of the 
 back arrive at the trunk without meeting any glands; but 
 Mascagni, whose authority in these matters is so great, assures 
 us that no lymphatic vessel reaches the trunk, unless it has 
 passed at least through one gland. 
 
 466. After a course more or less long, more or less inter- 
 rupted by ganglions, the lymphatic vessels of the inferior half 
 and of the superior and left quarter of the body, terminate by 
 a very elongated trunk, the thoracic duct, into the left subcla- 
 vian vein; the others terminate by a very short trunk in the 
 other subclavian vein. These modes of terminations are them- 
 selves subject to different variations. Does there exist other 
 terminations of the lymphatic vessels in the veins? A part of 
 this query must be examined here, and the other when we 
 shall speak of the lymphatic ganglia. 
 
 Several anatomists and physiologists have admitted this 
 opinion,* which may be founded on the circumstances that 
 every where, and especially in the mesentery, the known ra- 
 dicles of the lymphatic vessels have a capacity much greater 
 than that of the vessels which form their continuation; on the 
 circumstance that in this part of the body, also, there is often 
 found in the veins, as in the lymphatic vessels, substances in- 
 troduced by absorption, and even those which have been 
 directly injected into these latter vessels; and finally, on 
 the circumstance that the mere tying of the thoracic duct, 
 causes death only after ten or fifteen days, and that the sub- 
 stances introduced into the intestines, and absorbed by its in- 
 ternal membrane, arc then found in the blood. But this com- 
 munication has never been seen, nor is it generally admitted. 
 It would appear to be especially in the lymphatic glands 
 that it occurs; but we shall revert to this subject hereafter, 
 (art. ii. ) 
 
 * See Ludwig, be. cit. 
 
OP THE LYMPHATIC VESSELS. 309 
 
 467. The surfaces of the lymphatic vessels, like those of 
 all the vessels, are the one cellular and adherent, the other 
 smooth and free: the latter presents a multitude of valves. 
 
 These valves, which are of a semilunar or parabolic form, 
 are mostly arranged in pairs, and are large enough to close 
 tho vessel completely. They are generally placed at unequal 
 intervals, excepting in the vessels of the testicles, where they 
 occur nearly every line, which gives them more than any 
 other the appearance of a chaplet. They are more or less 
 close, according to the parts, without their being more parti- 
 cularly so in the branches than in the twigs; in certain vessels 
 there occurs spaces of several inches without valves: the 
 thoracic duct is especially remarkable in this respect. In 
 some points the insertion of a small vessel in a larger one is 
 only furnished with a single valve. In some places of the 
 trunks annular valves, that do not entirely close the canal, are 
 found. The insertion of the trunks into the subclavian veins 
 is furnished with a double valve, which effectually prevents 
 the reflux of the blood from entering into their cavity. All 
 these valves, like those of the veins and arteries, are formed 
 of a duplicature of the inner membrane. 
 
 468. Lymphatic vessels are formed of two membranes, 
 very distinct in their principal trunks. 
 
 The external, cellular and unequal or exterior is united to 
 the surrounding cellular tissue, which invests it with a sheath; 
 more deeply, it is distinctly fibrous or filamentous: it is even 
 supposed that muscular fibres have been observed in it. The 
 inner membrane is very thin. 
 
 Small sanguineous vessels, arteries and veins, have been fol- 
 lowed up into the thickness of the outer membrane; some say 
 that they have also seen in it lymphatic vessels. No one has 
 ever been able to perceives nerves in them. 
 
 469. The parietes of the lymphatic vessels, although very 
 thin and transparent, are dense and very resistant, much more 
 so than those of the veins, taking into consideration the differ- 
 ence of their thickness. Nevertheless, these vessels are exten- 
 sible, and also very retractile. Elasticity is manifest in them: 
 
310 GENERAL ANATOMY. 
 
 if they are filled and distended in the subject, the matter which 
 is introduced into them, is rejected. 
 
 Vital irritability or contractility* is no less evident in them: 
 although Mascagni and several others have denied it. If they 
 be exposed to the air in a living subject, they manifestly con- 
 tract; if the thoracic duct or any other lymphatic vessel be 
 punctured after being tied, the liquid issues by jets, like the 
 blood which comes from a vein, while after death, it only 
 escapes in a sheet over the lips of the wound. It is true that 
 mechanical or chemical irritations do not produce movements 
 similar to those of the muscles, but we must observe that irri- 
 tability varies according to the organs. 
 
 We know nothing concerning their sensibility, and little 
 about their force of formation. 
 
 470. The lymphatic vessels contain the chyle and lymph 
 [79]; they convey these humours from their radicles to their 
 trunk, which is very well proved by the arrangement of their 
 valves, which permits the fluid to flow in that direction, but 
 prevents it in an opposite one; by the effects of the ligature, 
 below which they swell while they empty themselves above; 
 and by the valves which are placed at their insertion in the 
 veins. The passage of the liquids through them is slow and 
 uniform, that is to say, they do not present any pulsation. 
 
 Darwin, Thilow and others, in order to explain the rapidity 
 of certain secretions, have admitted a retrograde movement of 
 the humours in the lymphatic vessels: in such a manner, for 
 instance, that the liquid absorbed by the parietes of the sto- 
 mach should be directly conveyed by the lymphatic vessels, 
 and by means of their communications to the kidneys, and 
 hence to the bladder. This would be to admit that the valves 
 do not present a very great obstacle to the retrograde motion 
 of the liquids. But it is certain, on the contrary, that the 
 valves oppose an insurmountable obstacle to the return of the 
 liquids; and moreover, observations and direct experiments 
 cause us to discover in the urinary passages substances intro- 
 
 * Schreger, de Irritabilltate vasomm lymphaticorurn. Lips. 1789. 
 
OF THE LYMPHATIC GANGLIA. 311 
 
 duced into the stomach, without the intermediate lymphatic 
 vessels presenting the smallest evidence of their passage. 
 
 ARTICLE II. 
 OF THE LYMPHATIC GANGL-IA. 
 
 471. The conglobate or ovoid glands, which interrupt the 
 continuity of the lymphatic vessels, stand in the same rela- 
 tion with respect to these vessels, as the nervous ganglia to 
 the nerves. 
 
 The ganglia were very anciently known. It is partly of 
 them that Hippocrates speaks under the name of glands. Fr. 
 Sylvius has given to them the epithet of conglobate* and Los- 
 sius that of lymphatic glands. According to the comparison 
 above mentioned and made by Soemmering, and to avoid con- 
 fusion, M. Chaussier has designated them under the name of 
 lymphatic ganglions. 
 
 472. They are situated in the course of all the lymphatic 
 vessels, beginning at the instep and at the fold of the arm, at 
 the elbow for the members, at the carotid canal and at the ex- 
 terior base of the cranium for the head. Many of them exist 
 in the neck, in the arm-pit, in the groin, several in the ante- 
 rior parietes of the thorax and abdomen, and a very great 
 number in these cavities. They exist especially very abun- 
 dantly about the roots of the lungs and in the mesentery, near 
 parts, consequently, which admit much extraneous matter. 
 None are known to exist in the cranium or in the spine. 
 
 Their size varies, in the healthy state, from that of a lentil 
 to that of an almond. Generally, the smallest are situated 
 towards the origin of the vessels, and the largest towards their 
 trunks. The most voluminous and closest to each other are 
 formed towards the root of the mesentery, the smallest in the 
 epiploon; those of the head and arms are small. 
 
 Their figure is rounded, oblong and a little flattened; they 
 are more or less unequal at the surface; they generally have 
 the form of an almond. 
 41 
 
312 GENERAL ANATOMY. 
 
 The lymphatic ganglia are generally of a reddish white, si- 
 milar to flesh, but their colour varies according to the regions 
 they occupy; thus those which are subcutaneous have a deeper 
 colour; those in the environs of the liver are yellowish, those 
 of the spleen brown, those of the lungs blackish, those of the 
 mesentery very white, &c. 
 
 Their consistence is greater than that of any soft part. 
 
 473. The lymphatic ganglions are enveloped in a thin 
 fibrous, very vascular, membrane, united to the surrounding 
 cellular tissue, and which sends fine and soft prolongations 
 into the interior. 
 
 The lymphatics, whose course is interrupted by glands, are 
 distinguished into those which come to these glands, vasa in- 
 ferentict) and in those that issue from them, vasa efferentia'. 
 they are distinguished from each other by the direction of 
 their valves. The number of vasa inferentia is very varia- 
 ble, they may be from one to twenty or thirty; that of the 
 vasa efferentia is also variable, seldom correspondent, and 
 ordinarily fewer. The first mentioned enter the gland on the 
 side nearest to the origin of the system, the others issue from 
 the opposite extremity, which corresponds to the trunks. The 
 vasa inferentia, in approaching the gland, divide themselves 
 into twigs, which go off radiating around it, divide and sub- 
 divide themselves at its surface, so as to surround it with a 
 net-work. The vasa efferentia produce nearly the same effect 
 at the other extremity of the gland, by the successive reunion of 
 their radicles and of their roots in trunks more or less numer- 
 ous and voluminous. The total capacity of the vasa efferentia 
 seems generally smaller than that of the vasa inferentia; this 
 is particularly obvious in the mesentery. 
 
 The lymphatic glands have also remarkable sanguineous 
 vessels. The arteries are sufficiently numerous and volumin- 
 ous, so that when injected, the glands are entirely coloured by 
 it. The veins, still more voluminous than the arteries, are 
 deprived of valves. Nervous filaments may be seen reaching 
 these organs and transverse them; but it is very difficult to 
 ascertain whether some filaments terminate in them, or whe- 
 ther they are merely crossed by them all. Two great anato- 
 
OF THE LYMPHATIC GANGLIA. 313 
 
 mists entertain opposite opinions on this subject: Wrisberg 
 admits them, and Walter rejects them. 
 
 474. Anatomists do not agree any better with reference 
 to the internal conformation and the texture of the lymphatic 
 glands. Albinus, Ludwig, Hewson, Wrisberg, Monro, and 
 Meckel, consider their tissue as entirely vascular; Malpighi, 
 Nuck, Mylius, Hunter and Cruikshank, admit of cells in them; 
 Scemmering admits these two kinds of texture, and a third 
 resulting from their combination. The examination I have 
 made myself of this tissue in man, in several animals, and 
 especially in the inguinal glands of cows which died during 
 lactation, has shown me that it results entirely from vessels, 
 but which present an erectile disposition more or less obvious. 
 In fact, among the vasa inferentia which penetrate into the 
 thickness of the gland, some acquire and preserve a great 
 tenuity, others dilate in cells like the veins of the penis, both 
 having numerous anastomosing communications. The roots 
 of the vasa efferentia present, on the other hand, the same 
 disposition, that is to say, that some are fine radicles, and the 
 other roots swelled or dilated in cells. The greater number 
 of the lymphatic glands present in their interior this mixture 
 of minute ramifications and enlarged parts. Some only pre- 
 sent twigs dilated in cells; some others, seem to consist only 
 in a net-work of fine ramifications. It is by these varieties 
 that we may explain the diversity of opinions which has ex- 
 isted on this point of anatomy. 
 
 The lymphatic glands contain in their interior a cream-like 
 substance, which appears to be contained in the fine or large 
 vessels which compose them, and not in the cellular tissue. 
 
 475. These ganglia are more voluminous, softer, more 
 reddish, and contain more liquid in children and young sub- 
 jects than in adults; they greatly diminish, but do not dis- 
 appear in old age. There is no well marked difference in 
 this respect between the two sexes. Hewson says that they 
 are larger in man: Bichat says, however, exactly the reverse. 
 Under the skin of negroes they are found black. 
 
 476. The function ascribed to the lymphatic glands is, 
 that they serve to mix the liquids arriving by the different 
 
314 GENERAL ANATOMY. 
 
 vasa inferentia, and to the elaboration of the lymph and chyle. 
 The liquids are afterwards conveyed away by the vasa efferen- 
 tia, and perhaps in part also by the veins. This point has 
 been denied by many celebrated anatomists and physiologists, 
 such as Haller, Cruikshank, Hewson, Mascagni, Soemmer- 
 ing, &c.; but it is to be feared that the authority of these great 
 men, may have caused a truth to be rejected, without previ- 
 ous examination. 
 
 Besides the facts already related favouring the opinion in 
 question, we may remark that many observers have perceived 
 striae of chyle in the vena porta; we may add that a great 
 many anatomists have seen and I have often seen, the mercury 
 introduced into the lymphatic vessels of the mesentery, pass 
 beyond a gland, both in the vasa efferentia and in the veins of 
 the gland; now this passage is too easy and too constant to de- 
 pend on a double rupture, and not to a natural communication 
 of the lymphatic vessels and veins. 
 
 477. Besides the lesions of the glands and lymphatic ves- 
 sels,* such as the inflammation of both, the wounds and rup- 
 tures of the vessels, their varicose dilatation, their narrowing 
 and obliteration, tubercles and other morbid productions in 
 the glands, &c. authors have caused the lymphatic system to 
 play a very great and indeed exaggerated part in most dis- 
 eases, by considering it as an apparatus of absorption. 
 
 * S. Th. Soemmering, de morbis vasorum absorbentium corp. hum. in 8vo. 
 Traj. ad Mcen. 1795. 
 
OF THE GLANDS. 315 
 
 CHAPTER V. 
 
 OP THE GLANDS. 
 
 478. The name of gland,* glandula, oS^u, is derived, ac- 
 cording to Nuck, from the similitude the ancients thought to 
 perceive between the lymphatic ganglions or glands, and the 
 fruit of the oak. 
 
 Objects so different have been comprised under the name of 
 gland, that much difficulty is experienced in defining it. 
 
 Hippocrates had announced that the glands were formed of 
 a peculiar granular and spongy flesh, not dense, having the 
 colour of fat, the consistence of wool, easily mashed between, 
 the fingers, provided with numerous veins, and when cut 
 emitting whitish and serous blood. He comprehended many 
 parts under this name, and especially the brain. 
 
 Anatomists for a long time also had a vague idea of the 
 glands, they have ascribed to them a rounded form; they 
 then have comprehended with the glands and the vascular 
 ganglions, the pineal gland, and hypophysis of the brain, the 
 synovial adipose bodies, and even the tongue. 
 
 Another definition, founded on the texture, and in which 
 there entered the idea of a mass of follicles or an aggregate of 
 
 * Warton, adenographia. Lond. 1656. M. Malpighi, de viscerum strue- 
 turdy in op. omn. et de struct. glanduL eonglob. 6?e. in op. posth. Lossius 
 and Pielow, JDisq. de glandulis in Genere. Viteb. 1683. A. Nuck, Adeno- 
 graphia curiosa. L. B. 1691. G. Mylius, de glandulis. L. B. 1698 L. 
 Terraneus, de Glandu. universim, &c. L. B. 1729. Boerhaave and Ruysch, 
 de Fabrica glandular, &c. in Ruyschu op. omn. A. L. de Hugo, comment, de 
 glandulis in genere, &c. Gotting. 1746. Th. de Bordeu, Recherches ana- 
 torn, sur les glandcs, 6fc. Paris, 1751. G. A. Haase, de glandularum de/i- 
 nitionc. Lips. 1804. Leonhardi, op. cit. 
 
316 GENERAL ANATOMY. 
 
 vessels with a peculiar membranous envelope, still compre- 
 hended many different parts, and supposed an exact know- 
 ledge of the intimate texture. 
 
 It has also been attempted to define the glands by their func- 
 tion, by saying that they are secreting organs; but by after- 
 wards confounding nutrition and secretion, the greater number 
 of the organs were included in this definition; or by distinguish- 
 ing these functions from each other, but not separating intrinsic 
 from excretory secretions, the serous and synovial membranes 
 were confounded with the glands. 
 
 In order to distinguish the glands from all other parts ana- 
 logous to them in form, in apparent texture, and even to 
 a certain extent in functions, we must take particular notice 
 of their connexions; Bichat and Chaussier have taken this 
 consideration for the basis of a definition of the glands; Haase 
 has likewise adopted it; but he has supposed excretory ducts 
 to the vascular ganglions. The glands are organs of an ob- 
 round lobular form, surrounded with membranes, having many 
 vessels and nerves, and provided with ramified excretory 
 canals which terminate at the surface of the tegumentary 
 membranes and pour out a secreted liquid. Finally, these 
 are the organs of extrinsic secretions furnished with excreto- 
 ry ducts. 
 
 479. The glands, when thus considered, are mere appen- 
 dages or prolongations of the tegumentary membranes. In 
 animals provided with vessels and a heart, the only ones which 
 have massive glands, they result from the intimate reunion of 
 these two kinds of organs: this is the reason why their de- 
 scription is placed here. They belong, however, more to the 
 tegumentary than to the vascular system, for in animals de- 
 prived of vessels, glands exist, but in a rudimentary state; 
 the liver, the most constant of all the glands, the kidneys ex- 
 cepted, exists, in fact, in insects under the form of a ramified 
 excretory canal, terminating in the intestinal tube, but floating 
 and free in the abdomen. 
 
 480. It is also pretty difficult, and perhaps impossible, to 
 establish a well marked line of distinction between the folli- 
 cles or crypta? and the glands. 
 
OP THE GLANDS. 317 
 
 We have already stated, that among the follicles some were 
 simple and solitary, others are grouped, collected or aggre- 
 gated, others again are composed either by their reunion in a 
 common orifice or lacuna, or at the same time by the agglo- 
 meration of several follicles, or finally by a common and rami- 
 fied excretory canal. Here a difficulty presents itself, for 
 there is no good reason why the amygdales which have com- 
 pound lacunae, the molar glands, the prostate and Cowper's 
 glands, which have ramified ducts, should not be classed 
 among the glands, as well as the sublingual, the lachrymal 
 glands, &c. 
 
 The most perfect and least equivocal glands are: the lachry- 
 mal, the salivary, three in number on each side, viz. the pa- 
 rotid, the maxillary and sublingual ; the pancreas, the liver r 
 the kidneys, the testicles and mammae. The ovaries like the 
 testicles must be classed with this kind of organs. 
 
 481. The form of the glands is irregularly round, and 
 present a great variety. Some are single, like the liver and 
 pancreas, not symmetrical; others are double and very nearly 
 alike on both sides. 
 
 482. They are all situated at the trunk, and all, whatever 
 may be the apparent diversity of their situation, terminate by 
 their ducts in the mucous membrane or in the skin. 
 
 483. Their size differs greatly: the liver is one of the 
 most voluminous organs of the body, and on the other hand, 
 the lachrymal and sublingual glands and the ovaries are 
 scarcely half the size of the thumb. 
 
 484. In their interior, some are lobed and lobulated like 
 the lachrymal and salivary glands and the pancreas; the mam- 
 ma3 are less distinctly so; the testicles are so in another man- 
 ner; the kidneys are only so in the foetus; the liver is only 
 lobed externally. 
 
 In the former, the lobules seem to be formed of very small 
 particles, but similar and whitish; in the liver and kidneys, 
 we find two substances of different colour, arranged in layers 
 in the kidneys, and mixed in the manner of fine granite in the 
 liver. 
 
 485. The greater number of glands are enveloped with a 
 
318 GENERAL ANATOMY. 
 
 cellular membrane, and some with a fibrous one, some of 
 which are surrounded by a serous membrane, and others by a 
 great deal of cellular and adipose tissues. The internal face of 
 this membrane is continuous with the cellular tissue, more or 
 less loose, which exists abundantly in the glands. 
 
 These organs have many sanguineous and lymphatic vessels, 
 and few nerves: more, however, than the mucous membrane 
 generally, but less than the skin. The greater number re- 
 ceive only arterial blood ; the liver alone in man and the maYn- 
 miferous animals, the liver and kidneys in oviparous animals, 
 receive venous blood besides, which explains the nature of 
 the liquids, so different from the blood, and altogether excre- 
 tory, furnished by these glands. The number and volume, or 
 the total capacity of the arteries, are very different in the 
 glands, but nowhere greater than in the kidneys. The length, 
 course and mode of distribution of the vessels are also very 
 various. The difference of capacity between the arteries and 
 veins is very little discernible in the glands; and, in fact, the 
 greater part of the blood in them is transformed into secreted 
 humour, and conveyed away by the excretory canals. 
 
 486. These ducts commence by very fine, invisible, and 
 probably closed radicles, which unite with each other in the 
 manner of the veins, to form several trunks, as in the lachry- 
 mal, sublingual and mammary glands, or one alone, as in all 
 the other glands besides. These canals, either many, or single 
 for each gland, generally take a straight course, in the testicles 
 excepted, where it is tortuous, and terminate on the tegu- 
 mentary membranes. That of the ovary is alone interrupted; 
 those of the rnammse present, before their termination, oval 
 enlargements; those of the kidneys present at first an enlarge- 
 ment or pelvis, and then terminate in a single bladder for 
 both; that of the liver and that of each testicle have also a re- 
 servoir, but situated laterally, and to reach which the secreted 
 liquid is obliged to take a retrograde course. The canals of 
 the other glands present neither interruption, enlargements, 
 nor reservoirs. 
 
 The composition of the excretory ducts is always the re- 
 sult of a mucous membrane whose thickness diminishes in 
 
OF THE GLANDS. 319 
 
 proportion as it divides in more minute ramifications in the 
 glands. This membrane is invested externally by cellular 
 tissue, and by an elastic tissue; in some ducts by an erectile 
 one, as in the urethra, in the nipple, and perhaps in some 
 others; in some parts of the excretory passages, the mucous 
 membrane contains muscular fibres. 
 
 487. The intimate texture of the glands is little known. 
 Malpighi had advanced that each of the glandular grains, the 
 acini, ought to be considered as a follicle, and each gland as a 
 conglomeration of follicles, terminating in a common excretory 
 canal. This opinion was received and admitted without being 
 contradicted until Ruysch, and in his times defended against 
 him by Boerhaave. According to Ruysch, on the contrary, 
 the parts which have been called glandular grains, consisted 
 solely of minute intertwined vessels, in which the arteries 
 should continue and terminate in excretory canals. 
 
 In each of these two opinions there are some things true that 
 we must admit, and some parts inexact, that we mustr eject. 
 It is true, as stated by Malpighi, that a gland consists, like a 
 simple or compound follicle, of a canal closed at the extremi- 
 ty; it is true also, as it is affirmed by Ruysch, that each glandu- 
 lar grain, and that the entire gland consists of a mixture and 
 intertwining of minute vessels with the origins of the excre- 
 tory ducts; but it is as incorrect to say, as he has stated, that 
 the excretory ducts are the continuation of the arteries, as it 
 would be inexact to say with Malpighi, that the radicles of 
 the excretory ducts commence by enlargements or follicles. 
 Perhaps the hypothesis of Malpighi would be more probable 
 if confined to the granulated glands, as the salivary, the pan- 
 creas and lachrymal glands, which, in fact, so much resemble 
 compound follicles; and that of Ruysch would more likely be 
 true by applying it only to the liver, the kidneys and testicles, 
 the texture of which is so evidently vascular and canaliculated, 
 without, however, being able to affirm that true hollow follicles 
 exist in the first mentioned organs, and in the others direct 
 continuations between the arteries and the excretory ducts. 
 
 In support of this conjecture might be adduced the facility 
 with which, in the latter glands, injections pass from the ves- 
 42 
 
320 GENERAL ANATOMY. 
 
 sels to the excretory ducts, and vice versa; and the difficulty 
 encountered in obtaining the same results in the lobulated and 
 granulated glands. 
 
 However this may be, the texture of the glands seems very 
 positively to result from the intimate association of ramified 
 excretory ducts, closed at their origin, with blood-vessels, 
 lymphatics and nerves, situated in their intervals, dividing 
 and terminating in their thickness; the whole being united by 
 cellular tissue and enveloped in membranes. 
 
 488. The function of the glands consists in a mode of secre- 
 tion which is called glandular. All secretions generally con- 
 sist in the formation of a particular humour, of which the 
 blood furnishes the materials. Glandular secretion only dif- 
 fers from $e others, (the follicular and perspiratory secre- 
 tions,) by the greater complication of its organs. 
 
 With a single exception, the same blood, arterial blood only, 
 is sent into all the glands ; the number, the size, the direction, 
 the mode of distribution of the vessels, and the degree of 
 tenuity which they reach by their successive divisions, can 
 only have an influence on the quantity of blood which arrives 
 in the gland, and on the rapidity of its course. However, a 
 part of the blood being brought back by the veins, and another 
 liquid by the lymphatics, the glands pour forth through their 
 excretory ducts, humours as different from each other, as the 
 saliva, the tears, the bile, the urine, the sperm and the milk. 
 
 What are then the nature and cause of the conversion of the 
 blood into secreted humours? It has been thought that the 
 change and its cause were purely mechanical, and depend on 
 the size and shape of the openings through which the humours 
 issue from the vessels; it has been supposed with more proba- 
 bility, that it was owing to a chemical change, that is to say, 
 another elementary composition; but this change occurs only 
 in organized bodies, and in some of their organs. This differ- 
 ence is then owing to modifications of their substance, in the 
 same manner as we see different vegetables planted in the 
 same soil, and surrounded by the same atmosphere, produce, 
 some gum, others an acid, others resin, &c. Glandular se- 
 cretion, like the others, is then a function of the living and 
 
OF THE GLANDS. .'321 
 
 organized substance. The vessels carry to it the materials 
 contained in the blood, the production is even probably dis- 
 posed or prepared by the arrangement of the vessels and the 
 mode of circulation which results from it; but it is in the tis- 
 sue which forms the radicles of the excretory ducts that we 
 must seek for its essential and immediate instrument. Se- 
 cretion generally and glandular secretion in particular, are 
 evidently submitted to nervous influence; the effects of the 
 passions on secretions in general, those of diseases, of hyste- 
 ria, of hypochondria, &c. are sufficiently known. Brodie's 
 experiments have confirmed that which direct observation had 
 taught. 
 
 The application of a ligature to the veins of a gland greatly 
 augments its secretion. 
 
 489. The /first part which begins to be formed in the 
 glands is their excretory duct. In the embryo, this canal is 
 free and floating, as in insects. The glands are afterwards 
 lobate, for instance the kidneys, as they are in the arachnides 
 and crustacea. They are generally very voluminous in the 
 foetus and in the child. They diminish in proportion as the 
 organs of the animal functions are developed. Some change 
 their situation at the time of birth: these are the testicles and 
 ovaries. These glands and the mammae are greatly developed 
 at the epoch of puberty and wither in old age. 
 
 490. The glands present many individual varieties and 
 vices of conformation. Some are sometimes entirely wanted: 
 those of generation are mostly subject to this circumstance. 
 One of the double glands may be wanting or be less volumin- 
 ous than the other. Some remain often lobate, or very vo- 
 luminous, as in the foetus. Others are sometimes united as 
 the two kidneys in one. Others may keep their primitive 
 situation, as the testicles and ovaries; these latter are some- 
 times, on the contrary, protruded out of the abdomen. The 
 kidneys also may be situated a great deal too low, or in the 
 pelvis. 
 
 491. We often observe the atrophy of the glands, either 
 in consequence of external pressure, or of an accidental pro- 
 duction developed in their thickness: this also occurs for want 
 
322 GENERAL ANATOMY. 
 
 of action, or even without an appreciable cause. Hypertro- 
 phia sometimes takes place as the effect of the cessation of the 
 action of other organs and especially of a double gland. It is 
 frequently accompanied with some alteration of structure. 
 
 492. The inflammation of the glands is common, and often 
 occurs by extending all the way in the excretory canal, from 
 its orifice to its radicles in the gland. Inflammation in them 
 is often suppurative and sometimes plastic; from which results 
 the obliteration of the ducts and the induration of the tissue. 
 
 493. Accidental productions, either healthy or morbid, are 
 very common in the glands. The ovaries are most subject to 
 them, but especially to analogous productions; the testicles, 
 the liver and mammae, are very subject to morbid ones; the 
 lachrymal and salivary glands, and pancreas, are, on the con- 
 trary, very little liable, either to the one or to the other acci- 
 dental productions. 
 
 494. Glandular tissue is not produced accidentally. When 
 it is wounded, the radicles or trunk of the excretory duct be- 
 ing divided, the secreted matter is poured into the wound, 
 which has a great tendency to become fistulous and to remain 
 so. 
 
 495. Here ends the description of all the systems or kinds 
 of organs which belong especially to the vegetative functions; 
 those which remain to be described belong more particularly 
 to the animal functions. This distinction would be obvious did 
 not one of the tegumentary membranes, the mucous membrane, 
 belong principally to the functions of nutrition and generation ; 
 while the other, the skin, is chiefly subservient to the sensa- 
 tions: it is the tegumentary system which unites the two classes 
 of functions and organs. 
 
OF THE LIGAMENTOUS TISSUE. 323 
 
 CHAPTER VI. 
 
 OF THE LIGAMENTOUS TISSUE. 
 
 496. The ligamentous or desmous tissue, textus desmosus, 
 is white, flexible, very tenacious, and forms very solid ties 
 and envelopes. 
 
 It has been designated by the names of fibrous, albugineous, 
 tendinous, aponeurotic, &c. tissue. These two latter names, 
 as well as that of ligamentous, have the inconvenience of de- 
 signating one particular kind of this tissue, and the first, a qua- 
 lity common to many others; for which reason the name 
 desmous appears to me preferable, because, although it signi- 
 fies ligamentous, it has not been applied to the ligaments in 
 particular. 
 
 497. The most ancient anatomists, Hippocrates and Aris- 
 totle, confounded under the name of nerves all the white parts; 
 hence the names of aponeurosis, syneurosis, ineuration, semi- 
 nervous muscles, &c. The school of Alexandria, and especial- 
 ly Galen, have positively distinguished the ligaments, tendons 
 and nerves. 
 
 Galen and Vesalius had already noticed the analogy which 
 exists between the ligaments and some membranes; Ad. Mur- 
 ray had already indicated the very great resemblance which 
 exists between the tendons, ligaments and aponeuroses. Isen- 
 fiamm* has given some remarks on this tissue; but it is Bichat, 
 who first considered as a whole every part of this system un- 
 der the name of fibrous tissue. He comprehended in it the 
 elastic tissue, which I have separated from it, [361.] and ex- 
 
 * Bemerkungen iiber die fachsen, in Beitragefur die zcrgliederungskunst. 
 Band. i. Leipzig, 1800. 
 
324 GENERAL ANATOMY. 
 
 eluded another kind that I have united with it; it is the one 
 which he calls libro-cartilaginous of the articulations, and the 
 tendinous sheaths in which the tendons slide. 
 
 SECTION I. 
 
 OF THE LIGAMENTOUS TISSUE GENERALLY. 
 
 498. The ligamentous organs do not form a continuous 
 connected whole; a centre and a point of reunion has been 
 sought for all the parts of this system. 
 
 A very ancient opinion, anterior to Galen, but announced 
 in one of his treatises, ascribed to the pericranium the origin 
 of all the nervous membranes. It has been supposed that the 
 Arabs, in translating into their language the name meninges 
 by a word having the same signification, and also that of ma- 
 ter, considered the membranes of the brain as generating the 
 other membranes; this is, however, an error advocated by 
 Sylvius, who has represented the meninges as fecund am\ mo- 
 thers membranes. Since Bonn, and recently Clarus, have at- 
 tributed, in a manner, the same power to the enveloping apo- 
 neuroses. Bichat has indicated the periosteum as the central 
 part of the fibrous system. But this system, formed of inde- 
 pendent parts, has not, properly speaking, any centre; some 
 of its parts are even entirely isolated from the others. It is, 
 however, a very generally disseminated tissue, having great 
 affinity to the cellular tissue, and in various places continuous 
 with it 
 
 499. The ligamentous tissue presents itself under two 
 principal forms, that of the band or cord, as the ligaments and 
 tendons; and that of membrane or envelope, as the periosteum, 
 the dura mater, the sclerotica, &c. These two forms, funi- 
 cular and membranous, are confounded in certain parts, which 
 are elongated and rounded at one extremity, expanded and 
 flattened at the other, such are certain tendons; besides, the 
 membranous form, although generally destined to make en- 
 
OF THE LTGAMENTOUS TISSUE GENERALLY. 325 
 
 velopes, sometimes also constitute ties: such are the capsular 
 ligaments, the aponeuroses of insertion, &c. The ligamentous 
 tissue has also been divided, according to its connexions, into 
 the parts subservient to the bones, to the muscles and other 
 organs; and according to its uses, into parts serving for attach- 
 ments or envelopes, or for both uses. 
 
 500. The colour of the ligamentous tissue is white; its as- 
 pect is generally shiny or silky. 
 
 501. Its texture is essentially fibrous, the fibres composing 
 it are very minute filaments, which are parallel or interlaced. 
 In long and slender tendons, the fibres are as it were braided; 
 in the aponeuroses, they are commonly disposed in several 
 layers crossing each other, and sometimes as it were inter- 
 woven. In some parts of this tissue, the fibres are so closely 
 united, that the whole appears homogeneous and not fibrous; 
 such are the cartilaginiform ligaments; but in every other part 
 we may, in dropsical subjects, or in parts which may have 
 been macerated, separate the fibrous bundles from each other, 
 and even the fibres themselves in fine filaments resembling the 
 threads of the silkworm. It is not known if this, be the last 
 point of division, but this is probable. These filaments are 
 white, tenacious, slightly elastic, flexible, and probably full or 
 solid. Fontana and Chaussier consider this fibre as being 
 primitive and particular; Isenflamm considers it as being form- 
 ed of cellular filaments impregnated with gluten and albumen; 
 Mascagni remarks that microscopical inspection seems to de- 
 monstrate that these primitive filaments result from a collec- 
 tion of absorbent vessels surrounded by a membrane formed 
 of these same vessels, and of another resulting from very mi- 
 nute blood-vessels making a very fine net-work. We see that 
 this is still the same idea already mentioned above [394.] 
 These filaments appear to be very condensed cellular tissue; 
 maceration softens and changes them into a mucous or cellu- 
 lar substance. 
 
 The various ligamentous organs are enveloped in sheaths 
 formed of cellular tissue; moreover, those which have distinct 
 bundles contain also some of this tissue in their interstitial 
 spaces; finally, the fibres themselves -are surrounded and bound 
 
326 GENERAL ANATOMY. 
 
 together by this tissue, that infiltration and maceration render 
 very apparent. We find adipose tissue also in the thickness 
 of the ligamentous organs. The ligamentous tissue is gene- 
 rally but little vascular; nevertheless, we find at its surface, 
 and we may follow into its substance some small blood-vessels. 
 In order to make them visible, we must, after having injected 
 them with a red injection, dry the part, then dip it in oil 
 of turpentine to render it transparent. Some portions of the 
 ligamentous tissue are very vascular; such especially are the 
 periosteum and dura mater. Lymphatic vessels are perceived 
 in the largest organs of this system. It is doubtful if there be 
 any nerves. 
 
 502. The ligamentous tissue naturally contains a great 
 proportion of water. Dessiccation renders it hard, trans- 
 parent, elastic and brittle; gives it a reddish or yellowish co- 
 lour, and renders its fibres only slightly distinct. It long re- 
 sists maceration, which softens and renders it floculent at its 
 surface, separates its fibres, by rendering apparent the cellular 
 tissue in its thickness, and finally converts the fibres them- 
 selves into mucous substance. Fire violently crisps it, and 
 leaves behind a large quantity of charcoal. Decoction crisps it 
 very much at first, renders it yellow, hard, elastic, and finally 
 reduces it into gelatin. Cold and warm mineral acids dissolve it: 
 nitric acid commences with crisping it. Cold acitic acid 
 swells and reduces it into a gelatinous mass; when warm it 
 melts it entirely. Alkalies swell and soften it; in this state its 
 fibres separate easily, and present the colours of the rainbow. 
 503. The elasticity of the ligamentous tissue when fresh is 
 very moderate, but it is strongly marked when dry. Its ex- 
 tensibility is almost null, when the effort is sudden; hence the 
 strangulation produced by ligamentous parts, and the rupture 
 of this tissue by violent distention. But when, on the con- 
 trary, the causes of distention act slowly and gradually, the 
 ligamentous tissue yield by becoming thinner and its fibres 
 looser, and if the slow distention be carried too far, they even 
 separate. We must not confound with this phenomenon the 
 augmentation of the volume of the fibrous tissue by excess of 
 nutrition. The retractility of this tissue is proportionate to 
 
OP THE LIGAMENTOTJS TISSUE GENERALLY. 327 
 
 the extensibility; it occurs quickly if the distention has been 
 sudden; without, however, producing laceration, and slowly if 
 it has been gradual and slow. The tenacity or power of re- 
 sistance of this tissue against laceration is very great; it per- 
 sists in all its energy even after death; the vital irritability 
 and contractility is null in this tissue; therefore we must not 
 admit, with Baglivi, movements of contraction, nor those of 
 oscillation with La Gaze. The sensibility of this tissue is ex- 
 tremely obscure and doubtful. Those writers who admit it, 
 confess that it is only developed by certain mechanical agents, 
 particularly for the various parts of this system. Thus the 
 dura mater should be sensible to the impression produced by 
 some excitants, which have no effect on other ligamentous 
 parts; ligaments should be sensible to distention, and to violent 
 pulling which precedes their laceration, while the same thing 
 does not occur in the tendons. Many doubts still exist on this 
 subject. It is wrong, however, to conclude from the experi- 
 ments favourable to the opinion of the insensibility of the liga- 
 mentous parts, that they experience no impression from irri- 
 tating causes; on the contrary, these causes induce inflamma- 
 tion, morbid sensibility, and diverse alterations in them. The 
 power of formation of the ligamentous tissue is very active. 
 
 504. The function of this tissue, entirely mechanical, is to 
 form ties, cords, very solid envelopes, which serve to attach 
 the bones with each other, and the muscles to the bones; to 
 inclose and contain certain parts; to transmit efforts, &c. 
 
 505. The ligamentous tissue is at first, in the embryo, soft 
 and mucous like all the other parts; it continues to have, dur- 
 ing gestation and infancy, a great deal of softness and flexi- 
 bility; it is then but slightly dense, more vascular, of a bluish 
 white, with pearly or silvery lustre, and easily soluble in boil- 
 ing water. Some parts, like the dura mater, the sclerotica and 
 periosteum, are thicker than in the adult; the tendons and apo- 
 neuroses, on the contrary, are more slender and thinner. In 
 old age, on the contrary, it becomes yellow, has less lustre, is 
 firmer, more coriacious, dryer, less vascular, and less soluble 
 in boiling water than it is in the adult. 
 
 Notwithstanding the firmness of the ligamentous tissue in 
 43 
 
328 CSENERAL ANATOMY. 
 
 old persons, it has not a very great predisposition to ossifica- 
 tion. The tendons are seldom ossified except where they rub, 
 and where they have a fibro-cartilaginous texture, and at their 
 extremity where inserted into the bones. The rare occurrence 
 of senile ossification of the tendons is so much the more re- 
 markable, as in various animals, as certain birds, or as the in- 
 sects and the Crustacea?, ossification or an analogous indura- 
 tion always occurs in the regular development of these parts. 
 
 506. The different parts of the fibrous system, although 
 sufficiently analogous to form one kind of organs, they are not, 
 however, identical; the texture of the tendons is less close than 
 that of the ligaments, that of the cartilaginiform ligaments is 
 so compact, that it appears almost homogeneous. The chemi- 
 cal composition of all these parts is nearly the same; the ten- 
 dons yield, however, much more easily to the dissolving action 
 of boiling water, than the other ligamentous parts. 
 
 507. The ligamentous tissue, when divided, torn or lace- 
 rated, reunites: this we see occurring in the ligaments after 
 luxations. The tendo achilli, or some other large tendon be- 
 ing lacerated, if the ends are kept motionless and in contact, 
 there occurs at first an agglutination between them, then an 
 organic reunion which, more extensible at first than the ten- 
 don, acquires in time its force of cohesion, or its tenacity and 
 its almost inextensible character. There takes place between 
 the extremities of divided muscles, and sometimes after the 
 fractures of bones, fibrous reunions. 
 
 508. The accidental productions of the ligamentous tissue 
 is pretty frequent, and presents itself under several forms. We 
 find membranes of this kind around certain cysts jivhich are, 
 however, seldom altogether enveloped by it. Some solid tu- 
 mours have also envelopes of the same kind. Preternatural 
 joints have also fibrous capsules more or less distinct. We 
 sometimes find fibrous bands in the serous membranes, and 
 especially in the pleura. 
 
 The isolated fibrous or ligamentous bodies have been very 
 anciently observed, but confounded with schirrhus ; M. Cham- 
 bon has described them under the name of scleromes. Walter 
 and Baillie were acquainted with them. Bichat, and after him 
 
OF THE LIGAMENTOUS TISSUE GENERALLY. 
 
 M. Roux, have described them; but it is to Bayle and to Laen- 
 nec that we owe our complete knowledge of them. They 
 have a globular form, their surface is unequal and as it were 
 lobated; the largest anfractuosities contain vessels and infil- 
 trated cellular tissue. When split they are seen to be formed 
 of lobules and convoluted bands, connected by cellular tissue, 
 and of fibrous prolongations. They have few vessels inter- 
 nally. They are at first small and soft like the fibrine of the 
 blood ; they progressively increase in size and change their tex- 
 ture; they seldom become cartilaginous, but frequently osseous; 
 an ossification of a strong hardness is developed in them in an 
 irregular manner, and resembles in their thickness to a mulber- 
 ry calculus. They are often formed in the texture and near the 
 surface of the uterus; sometimes in the ovary, in the acciden- 
 tal cellular tissue of the serous membranes, and are then formed 
 of layers like a bulbous root, in the cellular tissue; and it has 
 been said in the bones also; they have been seen in the fingers 
 and eye-lids, under the mucous membrane of the nose; the 
 fungi of the dura mater are sometimes bodies of this kind; 
 once they have even been seen in the brain. 
 
 Irregular fibrous productions are found in the cicatrices of 
 the liver, bones and skin; in the scrotum and elsewhere around 
 fistules. 
 
 509. There is a production which comes very near the 
 ligamentous tissue: it is that of a white compact tissue, not 
 fibrous, nor laminar, nor cellular, semi-transparent, not chato- 
 yant, soft and tenacious. Some organs in a state of atrophy, 
 appear to be transformed into this tissue; the cicatrices of the 
 skin, that of the cellular tissue after the cure of chronic-phleg- 
 mous, and after that of old fistulse, and some white granulations 
 of the serous membranes, resembling the glands of pachioni, 
 are of this kind. 
 
 There should also be referred to it, the sclerosis which is 
 observed in the cellular tissue and the skin in elephantiasis 
 of the limbs, scrotum, and vulva, and which has also been 
 seen in the subperitoneal cellular tissue, in a case of cancer. 
 
 It is to this production that we, must also refer the greater 
 number of the polypi of the uterus and especially of the va- 
 
330 GENERAL ANATOMY. 
 
 gina, and some tumours projecting under the skin; polypi and 
 tumours, whose white, compact, soft and tenacious tissue, 
 differs from the fibrous tissue, but bears more resemblance to 
 it than to any other. 
 
 These varieties of accidental white tissue have somewhat a 
 slight resemblance to morbid productions by their tendency 
 to spread and to reappear. 
 
 510. The inflammation of the ligamentous tissue is little 
 known, but is not of very rare occurrence. 
 
 It most frequently terminates by resolution, often also by 
 the production of a plastic or organizable matter, which is 
 sometimes absorbed, and at others gives rise to accidental ossi- 
 fication. Chronic inflammation softens this tissue, causes it to 
 lose its tenacity, and sometimes also gives rise to its ossification. 
 
 Some fungus of the dura mater contain polypi of the nasal 
 fossae, and posterior parts of the nostrils, certain epulies, some 
 tumours of the periosteum, are morbid productions or cancer- 
 ous degenerations of the ligamentous tissue. 
 
 SECTION II. 
 
 OF THE LIGAMENTOUS ORGANS IN PARTICULAR. 
 
 511. Overlooking for the present the h'bro-cartilaginous 
 tissue, the fibrous organs may be divided into those which 
 bind the bones with each other, those which attach the mus- 
 cles to the bones, and those which form envelopes. 
 
 ARTICLE I. 
 OF THE LIGAMENTS. 
 
 512. The ligaments,* ligamenta nervi colligantes, 
 cvfisor/toi, are the fibres which connect the bones and cartilages 
 with each other. 
 
 * Jos. Wcitbrecht, syndesmobgia site hialoria ligament, corp. hum, &c. 
 cum Jiguris, 4to. Petropol. 1742. 
 
OP THE LIGAMENTS. 331 
 
 The same name has improperly been given to many other 
 parts and especially to bridles formed by folds of the serous 
 and mucous membranes, to serous and adipose prolonga- 
 tions, &c. 
 
 The true ligaments are attached by their two extremities to 
 the bones and periosteum, and so firmly, that in the adult, it 
 requires an advanced stage of putrefaction to separate them; 
 but in children they separate from the bones with the perios- 
 teum by a moderate maceration. 
 
 The fibrous tissue which enters into their composition is 
 very dense, and arranged in more or less distinct bundles, very 
 closely connected; some go even so far as to have the appa- 
 rent homogeneous structure of the cartilages. 
 
 By decoction, they are resolved, though with difficulty, into 
 gelatine and albumen. 
 
 513. The ligaments are often affected with inflammation, 
 either through mechanical causes, as those of sprains and frac- 
 tures in the articular parts of the bones, or through the in- 
 flamed neighbouring synovial membranes, or through the spe- 
 cific causes of articular rheumatism and gout. Inflammation 
 gives rise to two different effects in the ligaments: namely, an 
 extreme softening and a loss of their power of resistance, or 
 accidental ossification. This last change is the most frequent; 
 the other is especially observed in the scrofulous diseases of 
 the articulations. 
 
 According to their connexions and uses, the ligaments are 
 distinguished in articular, non-articular, and mixed. The 
 first are those which are attached by their extremities to dif- 
 ferent bones that they connect, these are the most important; 
 the second kind are those, which attached to different parts of 
 the same bone, serve to close notches, as at the orbital arch 
 and at the superior margin of the scapulae, or to close an open- 
 ing and give attachment to muscles, like the obturator liga- 
 ment of the foramen ovale; the last are those which, like the 
 sacro-ischiatic and interosseous ligaments of the arm and leg, 
 are fixed to different bones, but serve especially for the inser- 
 tion of muscles. 
 
332 GENERAL ANATOMY. 
 
 The articular ligaments are distinguished into capsular and 
 funicular. 
 
 The capsular ligaments or fibrous capsules consist of cylin- 
 droid ligamentous sheaths which surround the articulation, 
 which are fastened by their two extremities to the two articu- 
 lated bones, and are lined internally by the synovial mem- 
 brane. These capsules, while they firmly connect the bones, 
 allow of motions in all directions. They are almost peculiar 
 to the scapulo-humeral and coxo-femoral articulations; how- 
 ever, rudiments of them are to be found in some others, in 
 which irregular bundles strengthen the synovial membrane 
 in several points of its contour. 
 
 The cords or ligamentous bundles of the articulations are 
 rounded strings or flattened bands, mostly situated outside of 
 the joints, and few of them only in the articular cavities, Both 
 permit movements in some directions, but prevent or limit 
 them in others. 
 
 The external ligaments are mostly placed at the two sides 
 of the articulation, and for this reason are called lateral liga- 
 ments; many moveable articulations are provided with them; 
 others are anterior and posterior; some, in consequence of 
 their direction, are called crucial ligaments. All these liga- 
 ments, which are attached by their two ends to the bones, 
 correspond by one of their faces to the synovial membrane, 
 and by the other to the surrounding common cellular tissue, 
 muscles and tendons. 
 
 The internal ligaments are surrounded by a sheath furnished 
 by the synovial membrane, which is reflected at their two ex- 
 tremities [212]. 
 
 ARTICLE II. 
 OP THE TENDONS. 
 
 515. The ligaments of the muscles or the tendons,* ten- 
 dines, tivovt^ydire ligamentous parts to which are attached the 
 extremities of the muscular fibres. 
 
 * Albinus, annoi. acad., lib. vi., cap. 7, et tab. 5. 
 
OF THE TENDONS. 
 
 Among the tendons, some are funicular, and have the form 
 of an elongated, rounded or flattened, but narrow cord, these 
 are the tendons properly so called; the others are expanded 
 and membraniform, those are the aponeurotic tendons or the 
 aponeufoses of attachment. 
 
 Both are chiefly placed at the extremities of the muscles, 
 and serve to insert them; the others, placed lengthwise and 
 interrupting the fleshy fibres, are tendons and aponeuroses of 
 intersection or enervations. 
 
 Among the tendons of insertion, there are even some, which 
 consisting in a multitude of small isolated fibrous bundles, 
 have neither the form of a cord nor of a membrane. 
 
 There are others which form arches attached by their two 
 extremities, and under which vessels pass; such is the one 
 under which pass the femoral vessels to become popliteal, &c. 
 
 Among the tendons there are some which have the form of 
 a cord in the greater part of their length, and which, at one of 
 their extremities, or both, expand into membranes. 
 
 There are others which are simple at one extremity, and 
 divide at the other into several cords or into laminae of greater 
 or less breadth. 
 
 The connexion of the tendons with the muscular fibres is 
 very firm; it has even been asserted that there are a real con- 
 tinuity and identity between these parts. But, besides the 
 difference of density and colour, besides the remarkable dif- 
 ference which is perceived with the microscope between the 
 two tissues, we remark aponeurotic tendons whose fibres have 
 a different direction from those of the muscles; the tendons 
 are moreover much less vascular than the muscles; they are 
 proportionally longer in children ; they separate from the 
 muscles by decoction; they are resolved into cellular tissue 
 by maceration; they are not irritable like the muscular fibres, 
 &c.; they are not the continuation of the latter, but simply 
 that of the cellular tissue of the muscles. 
 
 By the other extremity the tendons are attached to the 
 bones, and generally near the articulations. Some aponeu- 
 rotic tendons, instead of directly attaching themselves to the 
 
334 GENERAL ANATOMY. 
 
 bones, expand and are confounded with the envelopes of the 
 muscles. 
 
 The tendons are surrounded with common and lax cellular 
 tissue, or with mucilaginous bursae, according to the extent of 
 the sliding they experience. 
 
 Some are kept in their respective places by rings or sheaths. 
 
 The colour of the tendons is white, shining, bordering on a 
 green, silky or velvety. 
 
 The fibrous tissue which composes them contains in its in- 
 terstices, in the largest at least, some cellular tissue, and small 
 sanguineous vessels. 
 
 Some tendons have a fibro-cartilaginous texture; they are 
 those which rub against the bones. They even, in time, be- 
 come bony at these points. 
 
 Their essential properties are inextensibility and force of 
 cohesion, which renders them well calculated to transmit to 
 the bones the action of the muscles, the only function they 
 have to perform. 
 
 They are seldom altered; puncture induces in them an in- 
 dolent swelling which is slowly resolved. 
 
 ARTICLE III. 
 OP THE LIGAMENTOUS ENVELOPES. 
 
 517. The ligamentous membranes furnish to certain parts, 
 envelopes analogous to those that the cellular tissue forms 
 about certain other organs. These membranes are the folio wing: 
 
 A. OP THE ENVELOPES OP THE MUSCLES. 
 
 518. The envelopes of the muscles, or the enveloping 
 aponeuroses also furnish, in some places, insertions to the mus- 
 cular fibres; they are of two kinds, some surround the muscles 
 of the members, others invest those of the parietes of the trunk. 
 
 519. The enveloping aponeuroses of the limbs, fasciae 
 muscularesf are ligamentous membranes which surround the 
 
 * Ad. Murray, de Fastix hta. Upsal, 1774. 
 
OP THE ENVELOPES OP THE MUSCLES. 335 
 
 muscles of the limbs and binds them down to the bones. 
 These membranes have the form of sheaths; their external 
 surface corresponds to the cellular and adipose tissues, as well 
 as to the subcutaneous vessels and nerves. Their inner sur- 
 face corresponds to the muscles, furnishes attachments to some 
 of them, sends laminae between the greater number of them, 
 partitions, prolongations which separate them from each other, 
 which furnish attachments to them, and terminate by inserting 
 themselves on the ridges and lines of the bones. Their ex- 
 tremities are attached to the bones, receiving insertions or ex- 
 pansions of the tendons, losing themselves insensibly in the 
 cellular tissue, and in other places forming annular ligaments 
 to the tendons. They consist of one or more layers of liga- 
 mentous tissue of variable thickness, and are proportionate in 
 their thickness to the number and strength of the muscles that 
 they embrace; they present openings for the passage of vessels 
 from the deep to the superficial plane and vice versa. They 
 are provided with tensor muscles, either proper, or simply by 
 the expansion of their tendons. Their uses are to keep the 
 muscles in their proper places, and to furnish them with points 
 of attachment. They exercise by their resistance a slight 
 pressure on the deep vessels, and thus favour the venous and 
 lymphatic circulation. Their knowledge is of great im- 
 portance in a pathological point of view, on account of the 
 strangulations which they may induce; nor is its knowledge 
 less so in surgery, in consequence of their relations with the 
 muscles and vessels. 
 
 The thigh, the leg, the foot, the hand, the fore-arm and arm, 
 are provided with aponeuroses of this kind. 
 
 520. The aponeuroses of the parietes of the cavities of the 
 trunk, or the partial aponeuroses, invest, cover, and even en- 
 velop, at least in part, certain muscles: such are the compound 
 aponeurotic sheaths of the recti and pyramidales muscles of 
 the abdomen; the dorsal aponeurosis which covers the muscles 
 of the vertebral grooves; the temporal aponeurosis; the pelvic, 
 transversal, superficial, jugular aponeuroses, &c. Some, and 
 especially the latter, are not very distinct from the cellular 
 tissue, into which they are continued. 
 44 
 
336 GENERAL ANATOMY. 
 
 B. OF THE SHEATHS OF THE TENDONS. 
 
 521. The sheaths of the tendons are ligamentous canals 
 which embrace and fix the tendons in their place. 
 
 Some of them are sufficiently long to form true canals; 
 others, which are much shorter, are called annular ligaments. 
 Some of these annular ligaments are entirely circular; others, 
 as well as the sheaths, are completed by the neighbouring 
 bones, whence result osteo-ligamentous sheaths. They are, 
 together with the tendons which they contain, invested by va- 
 giniform synovial membranes. These sheaths are very solid 
 and strong; they contain each one or more tendons; they are 
 especially more numerous at the free extremities of the limbs, 
 more in the direction of flexure, and also stronger in this di- 
 rection than in that of extension. They keep the tendons in 
 their proper place, prevent their displacement during the 
 action of the muscles and the motions of the joints; they also 
 serve, in some places, as pulleys which change the direction 
 of the tendons and modify that of the motions. 
 
 C. OF THE PERIOSTEUM. 
 
 522. The envelope of the bones, or the periosteum, em- 
 braces the bones in their whole extent, excepting the articular 
 surfaces. The teeth alone, which however are not bones, are 
 destitute of it. 
 
 This envelope is interrupted at the amphiorthrodial and 
 diarthrodial articulations, but is not so at the immoveable 
 ones. 
 
 Its external surface is flucculent, and nearly covered with 
 filaments which confound themselves with the surrounding 
 cellular tissue, and which, in other places, are continuous with 
 the ligaments and tendons. 
 
 The internal surface is fixed to the bone by innumerable 
 prolongations which accompany the vessels into its interior 
 and into its substance. This surface is very firmly attached 
 to the bones wherever they are thick and spongy, but less so 
 in the other parts. Its adhesion is also less firm in children 
 than in adults. 
 
OF THE PERIOSTEUM. 337 
 
 The thickness of the periosteum is variable, and proportion- 
 ate to the vascularity of the bones. 
 
 Its texture is fibrous, and fibro-cartilaginous in the places 
 where the tendons rub. It has very numerous blood vessels,* 
 and in this respect forms a remarkable exception in the liga- 
 mentous tissue. Lymphatic vessels have also been observed 
 in it, but no nerves. 
 
 The periosteum is at first thin and has little vascularity 
 before the period of ossification. It becomes thjjik and vascu- 
 lar at this time. The use of madder does not colour it. 
 
 The functions of the periosteum are to envelop the bones, 
 support the vessels, unite the epiphyses, in childhood, to the 
 body of the bone, and to serve at this period to insert the liga- 
 ments and tendons. 
 
 The formation of bone has been ascribed to it, but without 
 any proof; for the ossification of the short bones is observed 
 to begin at the centre of the cartilage, and therefore far from 
 the periosteum ; and also of determining the form of the bones, 
 of limiting their growth by retaining the osseous humour, &c. 
 As to the part it may perform in the increase of the bones in 
 thickness, in the repairing the fractured bones or affected with 
 necrosis, will be examined hereafter, (chap, viii.) 
 
 The periosteum, when divided, reunites; when it is re- 
 moved a superficial necrosis is commonly produced, and it is 
 reproduced after exfoliation. When it is inflamed, sometimes 
 is terminated by resolution, at others by gangrene ; sometimes 
 it suppurates, and then separates more or less quickly from 
 the bone, which becomes affected with necrosis ; at other times, 
 the inflammation being plastic, a deposition occurs in its thick- 
 ness, producing a periostosis, which is sometimes dispersed 
 by absorption, and at others ossifies. The periosteum is fre- 
 quently the seat of a degeneration or of a cerebriform cancer- 
 ous production, at the centre of which the bone itself is not 
 very materially altered. 
 
 523. The perichondrium, a ligamentous membrane which 
 
 * See Ruyscli, adv. anal, dec iii. tab. H. fig. 8. Albums, Icon, oss- foetus, 
 Tab. xvi. fig. 162. 
 
33S GENERAL ANATOMY. 
 
 envelops the cartilages, differs only from the periosteum by 
 being less vascular. It fulfils, with respect to the cartilages, 
 the same functions as the periosteum with reference to the 
 bones, and moreover, it imparts to those which are thin and 
 flexible, a power to resist rupture, and a tenacity which they 
 do not of themselves possess. 
 
 D. OF THE FIBROUS ENVELOPES OF THE NERVOUS SYSTBM. 
 
 524. The nerves have a peculiar envelope, the neurilema, 
 which is of the same nature as the ligamentous tissue. Around 
 the spinal marrow, this envelope loses the firmness of the liga- 
 mentous tissue, and around the brain, where the pise-mater is 
 its continuation, it becomes simply cellular and vascular. The 
 neurilema, much less vascular than the pia3-mater, is still a 
 very vascular part of the ligamentous system. 
 
 525. The dura-mater or menix, which is vascular like the 
 periosteum, differs from this common membrane of the bones, 
 in being lined by the arachnoid, which converts it into a fibro- 
 serous membrane, because it forms a coat or capsule to the 
 brain and spinal marrow, in as much as in the cranium, the 
 only place where it also serves as a periosteum, it contains 
 sinuses or venous canals in its thickness, and forms prolonga- 
 tions or portions between the divisions of the brain. 
 
 E. OF THE COMPOUND FIBROUS MEMBRANES. 
 
 526. The pericardium and perididymes or tunica vagina- 
 lis are, like the dura-mater, fibro-serous membranes, being the 
 result of the intimate union of ligamentous membrane with 
 the external or parietal layer of a serous membrane. 
 
 In the nasal fossae and their sinuses, in the cavity of the 
 tympanum and mastoid cells, at the roof of the mouth and in 
 some other places also, the periosteum is immediately covered 
 by a mucous membrane which is intimately united to it, which 
 constitutes a fibro-mucous membrane. 
 
 These compound membranes resemble, in their texture, 
 functions, and alterations, the two kinds of tissue of which 
 they are formed. 
 
OF THE FIBRO-CARTILAGINOUS TISSUE. 339 
 
 F. OF THE FIBROUS CAPSULES OF SOME ORGANS. 
 
 527. Finally, the eye is contained in a capsular membrane 
 called sclerotica and cornea; the testicle in one which is named 
 albuginea, both remarkable for their thickness and firmness. 
 The ovaries, the kidneys, liver, and some other parts, have en- 
 velopes of the same kind, but not nearly so thick or solid. 
 Most of these capsules, in fact all of them excepting the scle- 
 rotica, have fibrous internal prolongations which extend into 
 the tissue of the organ. They are perforated by some open- 
 ings for the passage of vessels, but have very little vascularity 
 themselves. Their common uses are to determine the form 
 of the organs which they envelop, contain, support, and pro- 
 tect their internal parts. 
 
 SECTION III. 
 
 OF THE FIBRO-CARTILAGINOUS TISSUE. 
 
 528. The fibro-cartilaginous tissue is fibrous and tenacious 
 like the ligamentous tissue, of which it really forms a part; 
 white, very dense and elastic, like the cartilaginous tissue, it 
 seems intermediate between the ligaments and cartilages. 
 
 529. Galen has named certain ligaments neurochondroid 
 fvpo^ovSpw65 awfcs/toe; Vesalius calls them cartilaginous liga- 
 ments; Morgagni considers them as intermediate between the 
 ligamentsand cartilages; Weitbrechtcomprehends them among 
 the ligaments; Haase, on the contrary, classes them in the 
 chondrology, under the names of ligamentous and mixed car- 
 tilages. Bichat has established a fibro-cartilaginous system, 
 composed of the cartilaginiform ligamentcus tissue of which 
 we here speak, and of a part of the cartilaginous tissue, which 
 will be described in the next chapter; but this system of or- 
 gans does not appear to me to exist in nature, for which reason 
 I have rejected it. The fibro-cartilages, of which we speak, 
 
340 GENERAL ANATOMY. 
 
 seems to me to be but a variety of the desmous tissue: they 
 are cartilaginiform ligamentous organs. 
 
 530. The fibro-cartilages are either temporary or perma- 
 nent. 
 
 The temporary fibro-cartilages are those which pass regu- 
 larly, constantly, and at determinate epochs into the osseous 
 state: they are the fibro-cartilages of ossification. They are 
 found in the substance of the tendons and ligaments. They 
 are purely fibrous in the beginning, afterwards become fibro- 
 cartilaginous, and finally osseous. The patella and sesamoid 
 bones are developed in this manner. The places where the 
 tendons rub against the bones, those, for instance, where the 
 gemini are applied on the femur, and where the peronaeus 
 lungus lateralis slides on the tarsus, are also constantly the seat 
 of fibro-cartilages of this kind. The stylo-hyoid and thyro- 
 hyoid ligaments contain grains of the same nature in their 
 substance. The sclerotica, in certain animals, presents opaque 
 spots, equally fibro-cartilaginous, which afterwards form bony 
 plates. 
 
 531. The permanent fibro-cartilages, or at least those 
 which remain during the greater part of life, are of several 
 species. 1st, There are some which are free at their two sur- 
 faces: these are the inter-articular ligaments, menisci; they are 
 met with in thetemporo-maxillar and sterno-clavicular articu- 
 lations, sometimes in that of the acromion with the clavicle, 
 always between the femur and tibia, and between the ulna and 
 pyramidal bone. These ligaments, perfectly isolated at their 
 two surfaces, adhere by their edges or by their extremities. 
 2d, Others adhere by one of their surfaces; such are those 
 which are found wherever a tendon rubs against a bone, and 
 the presence of which is owing to the circumstance that the 
 periosteum becomes cartilaginous in these places; and those 
 the ligaments present, against which slides the tendons, as is 
 the case for the calcaneo-cuboidal ligament, against which the 
 tendon of the tibialis posticus rubs. Such are also the fibro- 
 cartilaginous roundish borders attached to the margin of the 
 glenoid and cotyloid cavities. Generally, wherever the fibrous 
 tissue is exposed to continued frictions, this tissue assumes a 
 
OF THE FIBRO-CARTILAGINOUS TISSUE. 341 
 
 cartilaginous texture or appearance, as is observed at the an- 
 nular ligament of the wrist, and the transverse ligament of the 
 odontoid process of the second vertebra; the pulley of the ob- 
 liquus major muscle also affords an instance of the same kind. 
 3d, Certain cartilaginous ligaments adhere by their two sur- 
 faces; the intervals between the bodies of the vertebrae and the 
 interval between the two ossa pubis, are filled up with organs 
 of this kind. Thus, according to their form and connexions, 
 there may be distinguished three kinds of cartilaginiform liga- 
 ments. 
 
 532. These organs, although always fibrous like the liga- 
 ments, and very dense like the cartilages, present a great num- 
 ber of varieties, with reference to the consistence and homo- 
 geneousness of their tissue. The minuei, or inter-articular 
 ligaments, for instance, present very distinct fibres at their 
 circumference, and towards their centre, which is thin, an ap- 
 pearance more and more compact and homogeneous, without, 
 however, meriting, even in that place, the title of true carti- 
 lages. The cartilaginous periosteum has more resemblance to 
 these latter. In the amphiarthrodial ligaments, a very appa- 
 rent fibrous tissue exists at the exterior. In proportion as it 
 approaches the centre, it becomes converted into a kind of 
 pulp or white pap which resembles cartilage, less in its con- 
 sistence, however, than from the disappearance of the fibres 
 and its apparent horaogeneousness. 
 
 533. There enter into the composition of the fibro-carti- 
 lages the same parts as into that of the ligamentous tissue: few 
 vessels occur in them. Their chemical composition has been 
 but little studied. They become yellow and transparent like 
 the ligaments, by desiccation. Decoction acts on them in the 
 same manner as on these latter; they are entirely melted by it 
 into a jelly, so that they do not, in this respect, participate of 
 the nature of the cartilaginous tissue. 
 
 534. Their physical properties are similar to those of the 
 ligaments and cartilages. Their tenacity or force of cohesion, 
 which is very great, and even exceeds that of the bones, ap- 
 proaches them to the ligamentous tissue. On the other hand, 
 they are very elastic, and quickly return on themselves when 
 
342 GENERAL ANATOMY. 
 
 they have yielded, either to distention or to pressure; it is 
 particularly when they are compressed that their elasticity is 
 most remarkable. They resist more than the bones and car- 
 tilages, the destructive action of pulsatile tumours. In aneu- 
 risms of the aorta, the vertebrae are worn and destroyed before 
 the fibre-cartilage which separates them. This property is a 
 consequence of their elasticity. The vital properties of the 
 fibro-cartilages are obscure, like those of the ligamentous tissue 
 generally. 
 
 535. In their formation, several of these parts pass through 
 the fibrous state ; others pass directly from the mucous to the 
 fibro-cartilaginous state. It is only accidentally, and in a va- 
 riable manner, that the permanent fibro-cartilages become 
 bony in old age; this, however, occurs more frequently to 
 them than to the ligaments, but less frequently than to the 
 cartilages. 
 
 536. The temporary fibro-cartilages have for use to serve 
 as a type or mould to bones. Those which are permanent, 
 sometimes form flexible, elastic, and very firm bonds, and 
 sometimes serve to facilitate slidings, by the consistency which 
 they give to the surface. 
 
 537. The morbid states of the fibro-cartilages are little 
 known. They unite again after being divided, as is observed 
 after the operation of symphyseotomy. 
 
 Their accidental production is not of very rare occurrence. 
 The centre of an intervertebral ligament may be taken as the 
 type of the species, and as an object of comparison. The ac- 
 cidental fibro-cartilages are, in fact, fibres, like the ligaments, 
 of a milky white like the cartilages, pliant, moist and elastic. 
 According to their form, connexion and uses, the accidental 
 fibro-cartilages may be divided into two kinds. Some are the 
 means of union of certain fractures which have not been con- 
 solidated, either on account of motions, like those of the neck 
 of the femur, the patella and others, or on account of an ex- 
 tensive loss of substance in one of the bones of the fore-arm, 
 leg, metacarpus, skull, &c. places where the fragments can not 
 be brought together. Other fibro-cartilages are formed on the 
 extremity of amputated bones, on the surfaces of supernume- 
 
OP THE FIBRO-CARTILAGINOUS TISSUE. 343 
 
 rary articulations, on and about the surface of the supplementary 
 articular cavities, and in some false anchyloses. Some shape- 
 less fibro-cartilages are found in some compound tumours of 
 the thyroid body, in certain cysts, and in some cicatrices, 
 especially those which occur in the lungs, after discharge of 
 tubercles. Layers of the same kind are found at the surface 
 of the spleen. The fibrous bodies of the uterus are sometimes 
 soft and pulpy at the centre, like the intervertebral ligaments. 
 Finally, we sometimes find globular and regular fibro-cartila- 
 ginous masses, which freely float in the serous cavity in which 
 they penetrate. Dr. Trouv6, of Caen, gave me a tumour of 
 this kind, as large as a walnut, which was found, together with 
 another of the same nature, in the peritoneal cavity. This 
 tumour, which is distinctly fibrous at the exterior, is soft like 
 the intervertebral ligaments towards the centre, and contains 
 in this place a bone of the size of a pea. 
 
 538. The inflammation of the fibro-cartilages has been but 
 slightly observed. All we know is, that in certain cases, the 
 desmo-cartilaginous parts become extremely soft in conse- 
 quence of an afflux of fluids, that is, by a kind of congestion. 
 This is observed in gestation, at the symphysis of the pelvis, 
 and which has been observed even in man, in the same arti- 
 culations. The vertebral column presents this softening in a 
 very marked degree in cases of rachitis. There results from 
 it a flexibility of the intervertebral ligaments, which makes 
 the column bend with the greatest facility, and should the in- 
 dividual keep himself habitually in an improper attitude, 
 causes the spine-to bend laterally in several places, and ulti- 
 mately involves the vertebrae themselves in the deformity. 
 
 One of the varieties of the vertebral diseases also consists 
 in the softening and swelling of the intervertebral ligaments, 
 which at length ulcerate and are destroyed. 
 45 
 
344 GENERAL ANATOMY. 
 
 CHAPTER VII. 
 
 OP THE CARTILAGES. 
 
 539. The cartilages X6v5pot, are white, hard, flexible, very 
 elastic, brittle parts, apparently homogeneous, which form the 
 skeleton of the vertebrate animals lowest in the series, (the 
 chondropterygious fishes); which in the beginning of the life 
 of other vertebrate animals fulfil the functions of bones; some 
 of which remaining in the adult age, form parts which are 
 solid, hard, and flexible at the same time. 
 
 540. The old anatomists and those of the Italian school, 
 disputed much respecting the matter which forms the bones 
 and cartilages, and about their differences; Galiardi and Ha- 
 vers in vain sought for this difference in the intimate texture 
 of the parts. More useful observations have been made in 
 the last century on the cartilaginous tissue. We are indebted 
 to Haase* for a very good dissertation on this subject; but 
 this anatomist, like several of those who preceded and fol- 
 lowed him, has confounded the condroid ligaments with the 
 cartilages, which renders his general description rather vague. 
 Bichat has separated from the other cartilages those which 
 are thin and very flexible, to form together with the cartila- 
 giniform ligaments, the fibro-cartilaginous system; but these 
 latter are in fact ligaments, and the former true cartilages. 
 
 541. The cartilages are either temporary or permanent: 
 the former constantly, completely and regularly disappear at 
 a determinate period of their growth, and are replaced by the 
 bones; the latter remain a much longer time, and sometimes 
 more than a century, in the cartilaginous state; however, 
 
 * J. G. Haase, de Fabrlca cartilaginum. Lips. 1767. 
 
OP THE CARTILAGES IN GENERAL. 345 
 
 several of them, at least ossify, sometimes even at the end 
 of the period of growth. The temporary cartilages will be 
 described along with the bones, (chap, viii.) We shall treat 
 here only of the cartilages called permanent: they form a 
 very natural genus of organs, and present also some differences. 
 
 SECTION I. 
 
 OF THE CARTILAGES IN GENERAL. 
 
 542. Some cartilages have an elongated form : such are 
 the cartilages of the ribs ; others are thick and short, like the 
 arythenoid and cracoid cartilages; but the greater number are 
 broad and thin. 
 
 Some are attached to the bones of which they cover certain 
 parts; others are prolongations of them and are firmly united 
 to them; others are connected to the bones by ligaments; 
 others are attached to each other, and have no other connexions 
 with the bones. 
 
 The cartilages are of a pearly white, and semi-transparent 
 when in their laminae; although they are the hardest parts of 
 the body after the bones, they are easily cut. 
 
 543. The cartilages, when examined in their substance, 
 present neither cavities, nor canals, nor areolae, nor fibres, 
 nor laminae, finally, nothing that indicates an organic texture; 
 they appear homogeneous. It seems, however, that they have 
 a distinct and different kind of texture in each species of carti- 
 lage: this assertion will be investigated hereafter. 
 
 All the cartilages, with the exception of those of the articu- 
 lar surfaces, are enveloped in a fibrous membrane, the peri- 
 chondrium, whicli has few vessels, and is not so intimately 
 connected with the cartilages as the periosteum is with the 
 bones. Neither nerves nor vessels have ever been discovered 
 in the cartilages; the cellular tissue is not apparent during life, 
 and after death they require to be macerated during several 
 months, even with young subjects, to reduce them to a mu- 
 
346 OENERAL ANATOMY. 
 
 cous substance analogous to the cellular tissue, and which, in 
 their ordinary state, must be an extreme degree of compact- 
 ness and condensation. 
 
 544. Cartilages contain a great quantity of water* or se- 
 rous liquid, which oozes at the surface when it is cut, and 
 which moistens it. In the adult man the proportion of water 
 that they contain is to the solid substance as 2i is to 1. Dried 
 cartilages become semi-transparent, yellowish, and susceptible 
 of being torn; steeped in water it resumes in four days its 
 weight and volume, its white colour, its flexibility, and partly 
 loses its transparency. 
 
 545. Submitted to the action of boiling water when in thin 
 lamina?, it at first crisps them and renders them yellow and 
 opaque. 
 
 The prolonged action of the boiling water on cartilages es- 
 tablishes between them a difference founded also on other 
 character; the cartilages of the joints are reduced into a jelly 
 by decoction, the other, on the contrary, resist its action. Al- 
 cohol renders cartilages slightly opaque. Diluted acids have 
 no action upon them ; when concentrated, they act as upon 
 the epidermis. Their chemical analysis is as yet imperfect. 
 It has been vaguely repeated, after Haller, that they are com- 
 posed of gelatine and earth. According to M. Allen, they are 
 composed of gelatine, and a hundredth of carbonate of lime. 
 Hatchett says that they are formed of coagulated albumen and 
 traces of phosphate of lime ; but we do not know to which 
 cartilages he alludes. M. Chevreul has found that the cartila- 
 ginous bones of the shark (sgualus) are composed of oil, mu- 
 cus, acitic acid, and some salts. J. Davy has found cartilages 
 formed of albumen 44, 5; water 55; and phosphate of lime 0, 5. 
 
 546. The physical property the most remarkable of the 
 cartilages is elasticity. They do not elongate and return on 
 themselves, like the elastic tissue; they generally do not yield 
 to pressure, like the chondroid ligaments, and afterwards re- 
 sume their thickness; but they are flexible, and return to their 
 
 * Chevreul, de f influence gue Feau exerce, &c. Jlnnaks de Chimie et de 
 Physique, tome 19. 
 
OP THE CARTILAGES IN GENERAL. 347 
 
 general former state with force and celerity whenever the cause 
 of flexion ceases to act. The articular cartilages alone are elas- 
 tic in the same manner as the fibre-cartilaginous tissue. 
 
 547. The vital properties and phenomena of formation, 
 irritation and sensation, are extremely obscure in the cartila- 
 ginous tissue. It is not known if the pain felt in the articula- 
 tion, and caused by foreign bodies when between the two sur- 
 faces, is to be ascribed to the articular cartilages, or rather to 
 the synovial membrane which invests them. 
 
 548. The functions of the cartilages depend solely upon 
 Iheir physical properties; upon their firmness, which enables 
 them to preserve the shape of certain parts ; upon their flexi- 
 bility and elasticity, which permit them to yield, at times, and 
 resume afterwards their former state. 
 
 549. The cartilages in the embryo and foetus, are at first 
 soft, mucous and transparent, like jelly or glue; the propor- 
 tion of water at this time is very great ; in the child, they are 
 yet slightly coloured, very transparent, very soft, and slightly 
 elastic. They afterwards become white, acquire firmness, and 
 the semi-opacity which characterizes them. Later, in old age, 
 they become whiter or yellower, more opaque, less flexible, 
 less elastic, more brittle and drier; the proportion of water di- 
 minishes, and that of the earthy substance increases. They 
 at last ossify, at least in some points. This alteration com- 
 mences sometimes as soon as the adult age, but especially in 
 old age. Inflammation prematurely determinates this change. 
 
 550. The organic action of nutrition seems to be very slow 
 in it. The use of madder does not colour them ; that. substance 
 appears to have affinity only with the earthy substance of 
 bones. They become yellow in jaundice. The cartilaginous 
 bones of the vertebral column of the lamprey appear and dis- 
 appear every year, from which they must be inferred to pos- 
 sess a great organic activity, which is also the case with the 
 rapid growth of the larynx towards the period of puberty. 
 
 551. Accidental cartilaginous productions are very com- 
 mon, they have all the characters of natural cartilages: colour, 
 apparent homogeneity, c. They present all the varieties of 
 texture of the cartilages, and even more; we must therefore 
 
34S GENERAL ANATOMY. 
 
 divide them into two kinds. The imperfect accidental car- 
 tilages are sometimes in the state of jelly, or have the consist- 
 ence of the boiled white of egg. They have a milky, or yel- 
 lowish, or pearly-gray colour; they are partially or totally os- 
 sified, rather than becoming perfect cartilages. They are met 
 with under the form of incrustations in the arteries, and espe- 
 cially in the aorta and in the cerebral arteries; under the form 
 of cysts around morbid productions and acephalocysts; forming 
 the fistulous passages in the lungs; under the form of irregular 
 masses in goitres, and other compound tumours, and under 
 that of isolated bodies in the articulations. 
 
 The perfect accidental cartilages are those which present the 
 character of the natural tissue, and especially its firmness. 
 Some are found forming small cysts filled with phosphate of 
 lime. Some are sometimes met with in the state of isolated 
 bodies, of a moderate volume of an obround figure, in the syno- 
 vial membranes, or at their exterior, whence they penetrate 
 into the cavity by pushing the membrane before them, enve- 
 loping itself as with the finger of a glove whose base, after be- 
 coming very thin, separates. They imperfectly ossify either 
 in part or in totality, but beginning in the centre. These car- 
 tilaginous bodies are also found in the splanchnic cavities, and 
 especially in the tunica vaginalis, into which they penetrate 
 like those just described. 
 
 Perfect cartilages also occur under the form of incrustations 
 or plates, in the sub-serous cellular tissue of the spleen, the 
 lungs, and the pleura costalis, in the substance of the valves of 
 the heart, especially in the left side, in the sub-serous tissue of 
 the diaphragmatic pleura and peritoneum, and in that of the 
 liver in hernise, and seldom in the anterior parietes of the ab- 
 domen. All these incrustations have a great tendency to ossify. 
 Cartilages also happen in shapeless masses in the compound 
 tumours, under the accidental cellular tissue of the serous mem- 
 branes. 
 
 Accidental cartilages are sometimes formed by transforma- 
 tion of other tissues. An old woman who some years ago 
 was at the Hospital of the faculty of medicine at Paris, and 
 who had on her forehead a broad conoid horny production 
 
OF THE DIFFERENT KINDS OF CARTILAGES. 349 
 
 which grew on the cicatrix of a burn, having died, the bones 
 of the skull immediately under this horn were found to be 
 transformed into cartilages. Laennec saw a cartilaginous trans- 
 formation of the mucous membrane of the urethra. I have 
 observed the same thing in the vagina, in a case of prolapsus 
 uteri, and in the prepuce, in a case of congenital phymosis, 
 in an old man. I am at the same time of opinion that these 
 three cases belong rather to the desmo-cartilaginous produc- 
 tions. 
 
 552. Alterations* of the cartilages are rare and most com- 
 monly consecutive. They resist for a very long time the 
 destructive action of aneurismal tumours, and the propagation 
 of diseases of the neighbouring parts. The alterations to 
 which the} 7 are subject, and the reparation of their injuries, 
 are somewhat different in the various kinds of this tissue. 
 
 SECTION II. 
 
 OF THE DIFFERENT KINDS OF CARTILAGES. 
 
 553. The cartilages may be divided into three principal 
 kinds, with respect to their form, connexions, texture, pro- 
 perties and functions. 
 
 ARTICLE I. 
 A. OF THE ARTICULAR CARTILAGES. 
 
 554. The diarthrodial articular cartilagest are flat and 
 broad cartilaginous laminae, which tip or invest the surfaces 
 of the bones in the moveable articulations. These laminae 
 
 * Doerner, praeside Autenrieth, de Gravioribus quibusdam cartilaginum 
 mutationibus. Tubing. 1798. 
 
 |W. Hunter, Of the structure and diseases of articulating cartilages; in 
 Philos. trans. 1743. Delasone, sur V organisation dcs os ; mem. de Facad. des 
 sd. Paris, 1752. 
 
350 GENERAL ANATOMY. 
 
 have a free surface, covered by the synovial membrane which 
 is closely attached to it, and a surface which also adheres in- 
 timately to the surface of the bone, without a continuity of 
 tissue however existing between them. Their circumference, 
 which is thinner than the rest, extends to that of the articular 
 surfaces of the bones. Their thickness, which is inconsidera- 
 ble and proportionate to their breadth, is from one to two 
 lines in the largest, and a fraction of a line in the smallest. 
 It is not the same in the whole of their extent. Those which 
 incrust or tip convex bony surfaces are thicker at the centre 
 than in the remainder of their extent. Those of the concave 
 surfaces, on the contrary, are thicker at the circumference 
 than at the centre. 
 
 555. The texture of these cartilages is at first sight as in- 
 distinct as that of the others, so that they resemble a layer of 
 wax spread over the bone, but may be discovered by certain 
 modes of procedure, it is fibrous. Maceration of an articu- 
 lar part of a bone, continued for six months, effects the de- 
 struction of the synovial membrane, the only membrane co- 
 vering the cartilage which is destitute of the fibrous perichon- 
 drium, and produces disunion of the fibres of which it is 
 composed, which rise perpendicularly from the surface of the 
 bone like the pile of velvet. If a cartilage thus disposed by 
 maceration be dried, the fibres become smaller and thus sepa- 
 rate from each other, becoming more distinct. Decoction, 
 when not prolonged so as to dissolve the cartilage, produces 
 at first the same effect as maceration. The action of fire also 
 discloses the structure in the same manner. These cartilages 
 have no vessels. Delicate injection and microscopic inspec- 
 tion show the capillary vessels terminating at their circumfer- 
 ence and at their adherent surface, without ever penetrating 
 into their substance. 
 
 These cartilages, which are compressible and elastic, deaden 
 the effects of pressure and concussions. The smoothness of 
 their surface facilitates the motion of the diarthrodial articula- 
 tions. They become much thinner in old age. 
 
 556. In preternatural joints, no true cartilages are pro- 
 duced, but only desmo-chondroid tissue, a tissue which, in 
 
OP THE ARTICULATE CARTILAGES. 351 
 
 truth, greatly resembles that of the diarthrodial cartilages. In 
 the natural diarthrodial articulations, the destruction of the 
 cartilages is sometimes followed by their nearly perfect re- 
 production ; only the new cartilage produced at the surface of 
 the bone, being thinner, has a somewhat bluish appearance, 
 which is owing to its semi-transparency. The edges of the 
 old cartilage are free, and extend over the very thin contour of 
 the new cartilage. 
 
 In the joints of old persons affected with various other al- 
 terations, the diarthrodial cartilages are sometimes found con- 
 verted into villous fibres, free and floating. When laid bare 
 in amputation at the joints, if the wound unites by first inten- 
 tion, the cartilage and its synovial membrane do not unite, 
 but remain free behind the cicatrix. If the wound remains 
 open, if it inflames and suppurates, the cartilage is seen at the 
 end of some days to soften, and afterwards gradually to disap- 
 pear from the circumference to the centre, in proportion as 
 the granulations extend to the surface of the bone, and even 
 before they reach it. Inflammation of the diarthrodial carti- 
 lages is in general of rare occurrence; and, when it takes 
 place, commonly terminates by ulceration or absorption. This 
 ulceration of the diarthrodial cartilages is most commonly 
 consequent to inflammation of the synovial membrane or bone, 
 sometimes to that of the cartilage itself, but it also sometimes 
 seems not to be preceded by any inflammation. Sometimes, 
 before ulcerating, the cartilage softens and assumes a fibrous 
 appearance. This ulceration most commonly takes place in 
 young subjects, or before middle age. It is accompanied by 
 a pain, which is at first slight, but which gradually increases 
 in intensity. When the ulceration stops and heals, there 
 takes place a reproduction of cartilage, of which we have al- 
 ready spoken, or a bony production of the nature of ivory 
 or enamel, or, lastly, a union of the surfaces by anchylosis. 
 In the case of true anchylosis, the cartilages are always ab- 
 sorbed. 
 
 557. The cartilages of the synarthrodial articulations, are 
 extremely thin laminae, placed between the bones which are 
 articulated in an immoveable manner, and holding firmly on 
 
352 GENEBAL ANATOMY. 
 
 each side to these bones hy a kind of suture. Their edges, in 
 the interval between the bones, are intimately attached to ex- 
 ternal and internal periosteum, which passes from the one to 
 the other bone. Thus they greatly contribute to the solidity 
 of these articulations. These cartilages, in the sutures of the 
 skull, are thinner at the interior, than at the exterior of the 
 wall, which in pa-rt accounts for the quicker disappearance of 
 the sutures at the interior than at the exterior of the skull. 
 With respect to the frequency of their ossification, they are 
 intermediate between the temporary and the permanent car- 
 tilages. 
 
 ARTICLE II. 
 OF THE COSTAL, LARYNGEAL, AND OTHER CARTILAGES. 
 
 558. The costal cartilages* are the longest and thickest 
 cartilages of the body. They constitute cartilaginous prolon- 
 gations to the bony ribs. The first of them may also be con- 
 sidered as anterior or sternal cartilaginous ribs. The cartilages 
 are all attached to the anterior extremities of the ribs, like the 
 synarthrodial cartilages. The first is even continuous with 
 the sternum at the other extremity. The next six are articu- 
 lated with the sternum by diarthrosis. The three following 
 are in the same manner articulated with those which precede 
 them. The last two are immersed in the intermuscular cellu- 
 lar tissue. 
 
 559. The texture of these cartilages is very obscure, and 
 at first sight they appear homogeneous. However, by macera- 
 tion prolonged for at least six months, the costal cartilages di- 
 vide into oval laminae or plates, separated from each other by 
 circular or spiral lines; and united together by some oblique 
 fibres which they send into each other. These laminae are 
 themselves divided into radiated fibrils, and the fibrils at length 
 into minute bundles, which are at length reduced into mucous 
 
 * Heissant, Sur la. structure des cartilages des cotes de Fkomme et du cheval, 
 in Mm. de 1'acad. des sc., 1748. 
 
OF THE COSTAL AND LARYNGEAL CARTILAGES. 353 
 
 substance. All these divisions or separations are first pro- 
 duced at the circumference of the cartilage. The centre is 
 more homogeneous, and is the last part that divides. This 
 separation may be accelerated by drying in the sun a costal 
 cartilage that has been macerated for two or three months. 
 Acids produce a similar effect. 
 
 560. The costal cartilages are somewhat flexible and high- 
 ly elastic. In inspiration, the motion impressed upon the ribs 
 by the muscles, bends them and twists them upon themselves; 
 and when the muscular action ceases, they spontaneously re- 
 sume their original direction, and are thus agents of expira- 
 tion. 
 
 561. After adult age, and in old age, the costal cartilages 
 cease to be or to appear homogeneous. Their perichondrium 
 becomes opaque, and there are produced, between it and the 
 cartilage, and in its substance, bony plates, more or less nu- 
 merous and broad, which sometimes end with forming a more 
 or less complete bony sheath. This change almost always 
 happens to the first, commencing at its sternal extremity. The 
 other sterno-costal cartilages also experience it, but in a less 
 degree. The asternal costal cartilages, or those of the false 
 ribs, experience it still less, or not at all. At the same time 
 the costal cartilages become yellowish, then reddish in their 
 centre, which also presents more or less large and numerous 
 bony points, which sometimes at length occupy the whole car- 
 tilage. This latter phenomenon shows itself more frequently 
 and sooner in the asternal cartilages than in the others. 
 
 These changes in the cartilages are commonly the effect of 
 age. They commence towards the middle of life, and go on 
 continually increasing. Persons of a hundred and thirty and 
 a hundred and fifty years, however, have been seen to have 
 costal cartilages in their natural state. 
 
 When the cartilages begin to undergo this change, desicca- 
 tion causes them to break across in the centre, which has be- 
 come areolar, and not at the surface, which has, on the con- 
 trary, become denser. 
 
 They frequently ossify, and at an early age, in persons 
 affected with phthisis, 
 
354 GENERAL ANATOMY. 
 
 562. The costal cartilages, when denuded, do not produce 
 granulations, but are covered by those of the neighbouring 
 parts. When broken, they do not unite by a cartilaginous 
 substance, but a cellular lamina is produced between them, 
 and the broken place is enveloped with a bony ring furnished 
 by the perichondrium, and which is more or less regular, ac- 
 cording as the fragments have remained more or less exactly 
 in opposition. I have sometimes seen in man, and repeatedly 
 in the horse, the fractures of ossified asternal cartilages, united 
 by a bony callus. 
 
 The costal cartilages are subject to some vices of original 
 conformation, and are even liable to be wanting in whole or 
 in part. In the latter case, it is always the extremity next to 
 the rib that exists. When the thorax is deformed, when it is 
 contracted, as sometimes happens after the cure of pleurisy, 
 the cartilages of the affected side bend and become deformed. 
 
 563. The nasal cartilage, that of the auditory canal, and 
 that of the Eustachian tube, are in a manner articulated with 
 the bones. Those of the larynx, on the contrary, are only 
 attached to the bones by ligaments, and are connected together 
 by moveable articulations. 
 
 These cartilages have still a certain thickness. When their 
 perichondrium is raised, their surface is found to be smooth 
 and compact. Long continued maceration divides these carti- 
 lages into soft and short fibres or filaments. Decoction and mi- 
 neral acids produce the same effects. 
 
 These cartilages are flexible and elastic. By their solidity 
 they preserve the form and cavity of the organs which they 
 contribute to form. Those of the larynx present the remark- 
 able peculiarity of a very rapid growth at the period of puber- 
 ty. These same cartilages sometimes ossify from the adult 
 age, at least in part. Chronic inflammation of the mucous 
 membrane of the larynx, and its ulceration, greatly hasten 
 this ossification, which, in fact, always takes place in phthisis 
 laryngea,and is of frequent occurrence in phthisis pulmonalis. 
 
 When the thyroid and cricoid cartilages are divided, they 
 unite by bony laminae of the perichondrium, which are thicker 
 at the exterior than at the interior of the larynx. 
 
OF THE MEMBRANIFORM CARTILAGES. 355 
 
 ARTICLE III. 
 OF THE MEMBRANIFORM CARTILAGES. 
 
 564. The membraniform cartilages are those which Bichat 
 has placed in his fibro-cartilaginous system. They are very 
 thin, and possessed of great flexibility. 
 
 They are the palpebral cartilages or tarsi, the cartilage of 
 the ear, those of the nostrils, the cartilage of the epiglottis, 
 the median cartilage of the tongue, and the cartilages of the 
 trachea and bronchi. 
 
 These very thin cartilages are furnished with a perichondri- 
 um, which is very thick and very strong compared with them- 
 selves, and sends into their substance fibrous and cellular pro- 
 longations, some of which even pass entirely through them. 
 Their surface also is very uneven and porous. Maceration 
 continued for two or three months softens them, and reduces 
 them to the state of distinct fibrils at first, and finally into cel- 
 lular or mucous substance. 
 
 They are very flexible, perfectly elastic, and much less 
 brittle and more tenacious that the other cartilages. Like the 
 preceding, they concur in forming organs or canals, of which 
 they preserve the form and caliber. They are rarely ossified, 
 and only at a very advanced period of life. The rings of the 
 trachea alone present a more or less extended ossification in 
 the adult. In cases of phthisis, however, the cartilaginous 
 arches of the bronchi have been found ossified. In gouty per- 
 sons also, and after inflammation of the ear, the cartilage of 
 that part has been seen to become bony. In the case of goitre, 
 and even without this cause of pressure, the cartilaginous rings 
 of the trachea are sometimes found compressed from one side 
 to the other, and their middle part bent at an angle. The same 
 change of form is also observed in the bronchi. 
 
356 GENERAL ANATOMY. 
 
 CHAPTER VIII. 
 
 OF THE OSSEOUS SYSTEM. 
 
 565. The osseous system,* or the skeleton, 2%fMiw, re- 
 sults from the union of the bones, which are the hardest and 
 driest parts of the body. 
 
 566. It is of all the systems that which shows itself last 
 in the animal series; it appears along; with the nervous centre 
 (the spinal marrow and brain) to which it serves as an enve- 
 lope. 
 
 567. The same sense has not always been attached to the 
 words bone and skeleton. In the writings of Hippocrates and 
 Aristotle is found the source of the two principal ideas at- 
 tached to these words, and which are still a subject of contro- 
 versy among zootomists. 
 
 The author of the Treatise on the Nature of the Bones at- 
 tributes to them the uses of determining the form, the straight- 
 ness, and the direction of the body. This idea has prevailed, 
 and it is still generally admitted, that the principal functions 
 of the osseous system are to determine the form of the body, 
 and to facilitate its motions. Agreeably to this definition, 
 
 * The best works on osteology are the following: A. Monro, Anatomy 
 of the Bones and Nerves. Edin. 1726, 8vo. W. Cheselden, Osteographia t 
 &c. Lond. 1733. fol. B. S. Albinus, de Os&ibus carp. hum. Lugd. Bat. 
 1726, 8vo. Id. de Scekto hum. ibid. 1762. 4to. Id. Tab. sceleti et muscul. 
 ibid. 1747. fol. max. Id. Tab. ossium. ibid. 1753. fol. max. Boehmer. 
 Institutiones osteologicce. Halac-Magd. 1751. Tarin. Osteographie. Paris, 
 1753. Bertin. Traitt tfosteologie. Paris, 1754. Ed. Sandifort. Descrip- 
 tio ossium hominis. Lugd. Bat. 1785. Loschge. Die Knochen, &c. Ab- 
 bildungen und kurzen Beschr. Erlang. 1804. fol. Blumenbach. Getchichtc 
 und Btschreibung der Knochen. Getting. 1807. 
 
OP THK OSSEOUS SYSTEM. 357 
 
 the hard parts of the other articulated animals, and especially 
 those of the insecta and Crustacea, ought to have been assimi- 
 lated to the bones, for it is in the latter that voluntary motion 
 and the preservation of the form of the body are carried to the 
 highest pitch. Willis, in speaking of the crab, uses the fol- 
 lowing words: Quo ad membra etpartes matrices, non ossa 
 teguntur carnibus, sed carries ossibus. 
 
 Aristotle, however, who already considered the spine as the 
 origin, or centre, from which the bones are derived, had giv- 
 en the first intimation respecting the distinction which has in 
 these latter times been made between the bones and the other 
 hard parts of animals. According to this idea, the skeleton, 
 or osseous system of the vertebrate animals is, in fact, first, 
 and principally seen to consist of a longitudinal column, which 
 furnishes superiorly, or posteriorly, an envelope to the spinal 
 marrow and brain, and anteriorly, or inferiorly, another en- 
 velope to the organs of nutrition, and especially to the central 
 parts of the vascular system. Other less constant appendages 
 are subservient to motion through their articulations. All the 
 parts of the system, besides, may furnish attachment to mus- 
 cles. 
 
 The question, therefore, is, whether all the hard and dry 
 parts of the body of animals, those which determine its form 
 and facilitate its motions, are to be called bones and skeleton; 
 or if these names are to be restricted to the hard parts, pecu- 
 liar to the vertebrate animals, which form a central and median 
 column in the body, with a cavity for the nervous trunk, and 
 another cavity for the heart and aorta, and frequently lateral 
 appendages for motion. 
 
 According to M. GeoffYoi Saint-Hilaire, one of the natural- 
 ists who has engaged most deeply in the study of this point 
 of zootomy, and who has treated it with his original talent, 
 there is no doubt on the subject, and all the difference between 
 the skeleton of an articulate and a vertebrate animal, between 
 the rachis of a crustaceous animal or an insect, and that of an 
 osseous animal, depends upon the absence of a spinal marrow 
 in the former, and its presence in the latter; a difference which 
 renders necessary a rachis with two canals in the vertebrate 
 
358 GENERAL ANATOMY. 
 
 animals, and one with a single canal in the crustaceous. Ac- 
 cording to this last idea, if I understand it well, an insect or 
 a crustaceous animal could be correctly compared to a mon- 
 strous vertebrate animal deprived of brain and spinal marrow. 
 568. Be this as it may, however, with respect to this dif- 
 ference of opinion, altogether foreign to the anatomy of man, 
 there are three things to be considered in the osseous system; 
 the bones themselves, their articulations, and the skeleton 
 which results from their union. 
 
 SECTION I. 
 
 OP THE BONES. 
 
 569. The Bones, Ossa, Ocr^a, are the hardest parts of the 
 human body, those which by their union form the skeleton. 
 
 570. Each of the bones, and many parts of bones, have 
 received particular names. These names ought to be so much 
 the more precise and appropriate, that the names of many 
 other parts of the body are formed from them. 
 
 The name of several bones is an adjective taken substan- 
 tively with a common termination: for example, the frontal, 
 occipital, parietal, &c.* M. Dumerilt has proposed, as a means 
 of giving precision and accuracy to the language of anatomy, 
 to give the same termination to all the names of bones, and to 
 them only. 
 
 571. The number of the bones is very great, but different- 
 ly determined, according as we take the subject at a particular 
 age, or different subjects at different ages; and this is what has 
 most commonly been done. If, for example, it be wished to 
 determine the number strictly, taking the adult subject, the 
 sphenoid bone then occurs united to the occipital, and often to 
 the ethmoid; but the sternum is still divided into three parts, 
 
 * This mode of expression is correct in French, but it is incorrect in Eng- 
 lish, and we are obliged to say, the frontal bone, the occipital bone, See. 
 
 TRANS. 
 
 f Prqfet (Tune nomenclature anatomique, Magasin Encyclopedique, t. ii. 
 Paris, 1795. 
 
OF THE BONES. 359 
 
 and the hyoid bone is still composed of at least three distinct 
 pieces. 
 
 The following is an enumeration of the bones which most 
 anatomists agree in describing as distinct. 
 
 Twenty-four moveable vertebra. 
 
 Five pelvic vertebra^ united to form the sacrum or pelvic 
 bone. 
 
 Three or four caudal vertebras, united to form the coccyx. 
 
 Twelve ribs on each side; a single sternum, formed of three 
 distinct pieces in the adult. 
 
 An occipital bone, a sphenoid bone, an ethmoid bone, a 
 frontal bone, two parietal bones, two temporal bones, each 
 containing three ossicula tympani; a vomer, two upper max- 
 illar bones, two palate bones, two zygomatic bones, two nasal 
 bones, two lachrymal bones or ossa unguis, two inferior tur- 
 binated bones, an inferior maxillar bone. 
 
 A hyoid bone, composed, even in the adult, of three or five 
 distinct pieces. 
 
 The bones, which remain to be enumerated, are all paired, 
 or double, and are those of the limbs or extremities; viz. 
 
 The scapula, the clavicle, the humerus, the radius, the ulna, 
 the eight bones of the carpus, the five of the metacarpus, the 
 two phalanges of the thumb, the three phalanges of each of 
 the other fingers, and five sesamoid bones. 
 
 The coxal bone, the femur, the tibia and patella, the fibula, 
 the seven bones of the tarsus, the five bones of the metatarsus, 
 the two bones of the great toe, the three bones of each of the 
 other toes, and three sesamoid bones. 
 
 572. The situation of the bones is always internal, or deep. 
 Whether they form cavities for the nervous and vascular cen- 
 tres, or form the limbs, they are all covered by the muscles 
 and the teguments; none of them being external. 
 
 573. The bones vary greatly as to size, some being a fourth, 
 fifth, or sixth of the length of the body, while others have 
 scarcely a diameter of a few lines. With reference to size, 
 the bones are divided into large, middle sized, small, and ve- 
 ry small, or ossicula. 
 
 574. The form of the bones is symmetrical; Some are 
 47 
 
360 GENERAL ANATOMY. 
 
 single and median, the others lateral and in pairs. In the 
 former, the lateral halves are similar to each other; in the lat- 
 ter, each of the bones is similar to that of the opposite side of 
 the body. There are in this respect only very slight irregu- 
 larities. 
 
 The single bones, which are all situated on the median line, 
 are the vertebra, as well those which are moveable, as those 
 of the sacrum and coccyx; the sternum, the occipital bone, 
 the sphenoid, the ethmoid, the frontal bone, the vomer, the 
 inferior maxillar bone, and the hyoid bone. 
 
 All the rest are paired or double, and are situated on the 
 sides of the median line, at a greater or less distance from that 
 line. 
 
 The bones are divided according to their form, and accord- 
 ing to the proportion which their three geometrical dimensions 
 bear to each other, into long, broad, short, and mixed. In the 
 first, one of the dimensions greatly preponderates over the 
 other two; in the broad bones, the length and breadth greatly 
 exceed the thickness; in the short bones, the three dimensions 
 are nearly equal; and the mixed bones participate, in different 
 parts of their extent, of the characters of the bones of two kinds. 
 
 575. The long bones, ossa longa sen cylindrica, are situ- 
 ated in the limbs, where they constitute broken or jointed co- 
 lumns. The number of these bones, in each fraction of the 
 limbs, increases, and their length diminishes, as we recede 
 from the trunk. Each long bone is divided into a body or 
 middle part, and two extremities. The body or diaphysis, is 
 cylindrical in some of them, and in others has the form of a 
 triangular prism. It is generally a little bent and twisted. 
 The extremities are enlarged. 
 
 The broad bones, ossa lata, sue plana, are situated in the 
 trunk, where they constitute walls of open cavities, and more 
 or less solid. These bones, which are flattened in two oppo- 
 site directions, are curved, and some of them twisted. They 
 are semi-circular, quadrilateral, or polygonal. Their edges 
 are generally a little thickened. 
 
 The short or thick bones, ossa crassa, are situated in the 
 vertebral column, in the hand, and in the foot, where, by their 
 assemblage and multiplicity, they form solid and moveable 
 
OP THE BONES. 361 
 
 parts. They are globular, tetrahedral, cuneiform, cuboidal, 
 or polyhedral. 
 
 The mixed bones, ossa mizta, are those which partake of 
 the character of several kinds. They are numerous: the occi- 
 pital bone, the sphenoid bone, the temporal bone, the coxal 
 bone, the sternum. The ribs participate of the character of 
 the broad and short bones. The long bones themselves re- 
 semble the thick bones at their extremities. 
 
 576. There are distinguished in the external conformation 
 of the bones, parts, or regions of their extent. 
 
 In the single bones there are, in general, either an azygous 
 and median parts, and lateral parts, as the body and processes 
 of the sphenoid bone, the body and theapophysal masses of the 
 vertebrae, &c. or lateral parts only, united in the median line, 
 as the two halves of the frontal bone, &c. 
 
 Many bones divide into parts or regions, determined by 
 their mode of formation or development. Thus, the hip bone 
 is divided into ilium, ischium, and pubis, the sphenoid bone, 
 the ethmoid bone, the temporal bone, &c. into several regions 
 equally distinct by the mode of their development. 
 
 In other bones, the division into regions results solely from 
 the situation and uses of the parts. Thus, the outer surface of 
 the frontal bone is divided into an orbitar and nasal region, a 
 frontal region, &c. 
 
 There are also admitted in the bones geometrical regions or 
 parts of their extent. Thus, there are distinguished and de- 
 scribed in the long bones, a body or central part and extremi- 
 ties; in the broad bones, faces, edges, and angles, &c. but these 
 terms are not strictly applied, for planes and angles are very 
 rare and imperfect in the organization. 
 
 577. The bones present at their surface eminences and de- 
 pressions which are greatly diversified. 
 
 The eminences of the bones are distinguished into epiphy- 
 ses and apophyses. The epiphyses have relation to the de- 
 velopment, and will be described when we speak of it. 
 
 The apophyses are bony eminences, continuous with the 
 substance of the bones. They are extremely numerous and 
 highly diversified. Few objects in anatomy have, according- 
 
362 GENERAL ANATOMY. 
 
 ly, been more differently arranged. They are distinguished 
 into articular and non-articular. The former will be described 
 as we proceed. 
 
 The non-articular apophyses are somewhat rough. Their 
 size and their very diversified form allow them to be divided 
 into three kinds. Some, which are long and projecting like 
 a branch or a bony ramification, bear the name of branches, 
 processes, and apophyses, properly so called. 
 
 Others, which are shorter and thicker, bear the name of 
 protuberances, tuberosities, and tubercles. 
 
 The others, which are elongated, narrow, and little protrud- 
 ing, bear the name of crests, ridges, and lines. 
 
 The synonymy of these different kinds of eminences is very 
 complicated and difficult. They are generally designated each 
 by names derived from trivial and rather loose comparisons, 
 sometimes also by names derived from their situation, their 
 size, their direction, and their uses. 
 
 Their general use is that of affording insertion to ligaments 
 and tendons. 
 
 578. The external cavities of the bones are, like their emi- 
 nences, distinguished into articular and non-articular. It is 
 of the latter only that we have to speak here. 
 
 Of these cavities, some traverse, and others do not traverse, 
 the substance of the bone. Of the latter, some have a widened 
 entrance, sloped in all directions. These are fossae, fossettes, 
 and digital impressions. The others have the bottom wide, 
 and the entrance narrow, and are lined by the mucous mem- 
 brane, and filled with air. These are sinuses, and when they 
 are divided into several cavities, cells, or cellules. Others are 
 elongated, narrow, more or less deep. These are called fur- 
 rows, channels, meatuses, and grooves. The cavities of this 
 latter kind, when they exist on the edge of bones, bear the 
 name of notches or incisions. 
 
 Of the cavities which traverse the bones from side to side, 
 some follow the shortest course, through a thin bone, and are 
 holes, slits, or fissures, others follow a longer and variously 
 contorted course, and are canals, conduits, &c. 
 
 Sometimes several bones unite to form a cavity, as the skull 
 
OF THE BONES. 363 
 
 and vertebral canal, the pelvis, the thorax, the nasal fossae, the 
 orbits, &c. ; or even to form a hole or a conduit, as the spheno- 
 palatine hole, the foramen lacerum posterius, &c. the orbital, 
 palatal, and other conduits. 
 
 Of these simple or compound cavities, some lodge organs, 
 others furnish insertions, and others serve to transmit, or afford 
 a passage to certain parts. 
 
 In certain places of the bones, there occur a multitude of 
 small eminences and depressions, very close to each other. 
 This constitutes impressions or inequalities which serve for 
 insertions. 
 
 579. The bones have internal and closed cavities, which 
 are called medullary cavities, because they contain the medul- 
 la, or fat of the bones.(169) 
 
 The long bones have a large cylindrical medullary cavity, 
 which occupies their body, or middle part, and which, at its 
 extremities, communicates with the areola3 of the spongy sub- 
 stance. This cavity lodges the medullary system, and ren- 
 ders the bone lighter under the same volume, and stronger 
 with the same weight. 
 
 The extremities of the long bones, the short bones, the broad 
 bones, and especially their thick edges, contain areolar cavi- 
 ties, which also lodge marrow. 
 
 Lastly, there are some also whose substance is compact, con- 
 taining only microscopic medullary cavities. 
 
 580. The bones have also vascular canals for the vessels of 
 the marrow, and for those of their proper substance. 
 
 Each long bone has at least one canal of this kind, which 
 passes obliquely through the walls of the medullary cavity, 
 penetrates into it from above downwards in the humerus, the 
 tibia and the fibula, and from below upwards in the femur, the 
 radius and the ulna. This canal gives passage to the vessels 
 and nerves of the medullary membranes. 
 
 The extremities of the same bone, the short and thick bones, 
 and the thick edges of the broad bones, are furnished with a 
 very great number of wide canals, which in like manner afford 
 passage to vessels, and especially to large veins. 
 
 Lastly, the whole surface of the bone is riddled with a mul- 
 
364 GENERAL ANATOMY. 
 
 titude of small holes or orifices of canals into which very small 
 vessels penetrate. 
 
 581. The density of the osseous tissue is very great, but 
 it is not the sam,e in all parts of the same bone. With refer- 
 ence to this circumstance, the substance of the bone is distin- 
 guished into compact and spongy or areolar. The first is cor- 
 tical, or situated at the exterior of the bones. The other is in- 
 ternal. 
 
 The compact substance is that whose density is such that no 
 interstices are perceived in it by the naked eye, although it is 
 perforated with many medullary and vascular canals visible 
 to the microscope. In the long bones, these canals are longi- 
 tudinal. They have frequent lateral communications with the 
 great medullary canal, and the outer surface of the bone. 
 They are smaller towards that surface than towards the other. 
 Their mean diameter is the twentieth of a line. 
 
 The areolar, or spongy substance, is that which forms small 
 cavities, distinct!)' visible to the naked eye. This substance 
 presents several varieties, of which the principal are the fol- 
 lowing: It consists of filaments more or less fine, and of la- 
 minae of a like tenuity, in the extremities of the long bones, 
 and in the substance of the short bones; of reticulated filaments 
 and laminae at the internal surface of the medullary canal of 
 the long bones; and of strong laminae, forming narrow areolae 
 in the broad and thin bones, especially in those of the skull. 
 
 The two substances, or varieties of the more or less dense 
 tissue of the bones, are arranged in a particular manner in each 
 kind of bone. 
 
 In the long bones, the body is formed of compact substance, 
 and the inner surface of the canal is bristled with some reticu- 
 lated filaments and laminae. Towards the extremities, the 
 compact substance greatly diminishes in thickness, the areolar 
 or spongy substance becomes more and more abundant and 
 fine, the great canal ends by becoming continuous with the 
 spongy substance, with which the whole extremity of the 
 bone is filled. 
 
 In the broad bones, the two surfaces are formed of compact 
 substance. Wherever the bone is thin, these two laminae touch 
 
OF THE BONES. 365 
 
 each other. On the contrary, where it is thick, they are se- 
 parated by a layer of spongy substance, proportionate to the 
 thickness of the bone. In the bones of the skull, the inner 
 table, which is still denser, but thinner and more fragile than 
 the outer table, bears the name of vitreous lamina, and the 
 spongy substance, that of diploe. 
 
 The short bones are formed of spongy substance, surround- 
 ed by a layer of compact substance. 
 
 Lastly, the mixed bones, in the disposition of the two sub- 
 stances, participate in the nature of the kinds of bones to which 
 they belong. 
 
 The two varieties of tissue, or the two substances of which 
 we have been speaking, are, in reality, one and the same tis- 
 sue, one and the same substance, differently disposed, rarefied 
 in one part and condensed in the other. A piece of compact 
 substance is exactly the same thing as a lamina or a filament of 
 spongy substance. A given longitudinal section of a long 
 bone, contains, to appearance, the same quantity of osseous 
 tissue as another equal longitudinal section of the same bone; 
 but in the one, the substance, or tissue, is condensed, and leaves 
 a large canal in its centre, while in the other, the tissue is ra- 
 refied, and the canal replaced by a multitude of spongy areolag. 
 These two substances can be transformed into each other. 
 The essential difference which they present is, so to speak, 
 foreign to them; it depends upon the presence and the pene- 
 tration of the medullary tissue, and upon its numerous vessels 
 in the very substance of the spongy bone, and upon its con- 
 tact on one of the faces only of the compact bone. 
 
 582. The texture of the bones* is one of the points of 
 
 * Malpighi. dt Ossium structurd f in op. posth. D. Gagliardi, Anatome 
 ossium novis inventis illustrata.Ttlomx, 1689. Cl. Havers, Ostcologia nova, &c. 
 Lond. 1691. Description exacte des os, comprise en Irois iraiUs> par J. J. 
 Courtial, J. L. Petit, et Lemery. Delascne, Mem. sur F organisation des os t 
 in Mem. de tAcad. Royak des Sciences. Paris, 1751. J. F. Reichel, de 
 Ossium ortu alque structurd. Lips. 1760. B. S. Albinus, de Constructions 
 ossiuniy in Jlnnot. Jicad. Lib. vii. cap. 17. Perenoti, Mem. sur la construc- 
 tion et sur I'accrossement des os. Mem. de Turin, t. ii. 1784. A. Scarpa, 
 de Penitiori osaium structurd commentarius. Lip3. 1795, and Paris, 1804. 
 
366 GENERAL ANATOMY. 
 
 anatomy that has given rise to the greatest number of writings 
 and investigations. Malpighi, the first author who deserves 
 mention, considers the tissue of the bones as resulting from 
 laminae, fibres, and filaments, with an intermediate bony juice. 
 It is, according to him, like a sponge filled with wax. Gag- 
 liardi admits laminas or bractea3, and bony threads of different 
 forms, which resemble them. Havers is pretty much of Mal- 
 pighi's opinion, and admits laminae formed of fibres, and con- 
 nected by the bony juice. Lasone describes laminae formed 
 of ossified fibres, connected with each other by oblique fila- 
 ments. Reichel, having examined portions of bones softened 
 in a mineral acid, saw that they might be divided into lami- 
 nae, and then into fibres, forming a porous and tubular whole, 
 which is continuous with the spongy substance. Scarpa con- 
 cludes, from the examination of healthy and diseased bones, 
 of bones entire and deprived of earthy substances, and of 
 bones before and after their entire envelopment, that the osse- 
 ous tissue, even the compact substance, is a cellular and reti- 
 culated tissue, entirely similar to the spongy substance. Me- 
 dici has observed, and the circumstance has long been known 
 to those who extract gelatine from bones, that the compact 
 substance of the long bones, deprived of earthy salts by the 
 action of a weak acid, divides into several Iamina3 or layers, 
 adhering to each other by fibres. 
 
 583. To examine the texture of the bony tissue, it being 
 extremely hard, one is obliged to have recourse to chemical 
 processes which, in decomposing the bone, must have some 
 action upon the part which remains subjected to examination. 
 Be this as it may, if a bone be immersed for some days in a 
 vegetable acid, or in a mineral acid diluted with water, the 
 saline substance which enters in large proportion into the 
 
 V. Malacarne, Jluduarlum obs. et icon, ad osteoL et osteopath. Liidwigii et 
 Scarpoe, Patav. 1801. Howship, Microscop. Observ. on the Structure of 
 Bone, in Medico-Chir. Trans, vol. vii. Lond. 1816. M. Troja, Observazioni 
 es edperimcnti sullc ossa, Napoli, 1814. Medici, Esperienze intorno alia tis- 
 situra organica ddk ossa, in opuscoli scientifici, t. ii. Bologna, 1818. Const 
 derazioni intorno alia tess. org. ddk ossa, scritte da M. Medici, &c. in ripusta 
 allc oppos.falt. dal S. D. C. Spcranza, e dal S. Cav. Jl. Scarpa, Bologna, 1819 
 
OP THE BONES, 367 
 
 bone, is removed from it, and the bone, retaining its form and 
 size, but having lost a part of its weight, equal to that of the 
 earthy matter abstracted, has become flexible and tenacious 
 like the cartilaginiform fibrous tissue. In this state it is re- 
 ducible to glue or gelatin by decoction. In this state also, if 
 it be softened by maceration in water, the compact substance, 
 which presented no apparent texture, divides into laminae, 
 connected together by fibres. The laminae themselves, some- 
 what later, or with more difficulty, divide into fibres, which, 
 by a more prolonged maceration, swell, and become areolar 
 and soft, like the cellular or mucous tissue. 
 
 A long bone, examined by this method, divides at its mid- 
 dle part into several layers, of which the outermost enve- 
 lops the whole bone, and of which the next, becoming thinner 
 towards the extremities, are continuous with the spongy sub- 
 stance with which they are filled. The broad bones are 
 formed of two laminae only, and the short bones of a single 
 lamina which envelops them ; this latter, like the others, 
 presenting at its internal surface filamentous and laminar pro- 
 longations which constitute the spongy substance. 
 
 The bony fibre differs therefore especially from the other 
 animal fibres in the great quantity of earthy substance which 
 it contains. 
 
 In fact, if in place of removing this earthy substance and 
 examining the organic residuum of which we have just spoken, 
 this latter be destroyed, by submitting a bone to the action of 
 fire, there remains a white substance, preserving the volume, 
 form, and a great part of the weight of the bone. This hard, 
 but very fragile substance, is an earthy salt, which forms part 
 of the bony tissue. The other tissues leave, after combustion, 
 a similar residuum or ashes, but in much less proportion, and 
 not preserving, like those of the bones, the form and a part of 
 the solidity of the whole. 
 
 584. The bony fibre is therefore a fibre very similar to 
 the cellular one, but differing from it in the very great quan- 
 tity of earthy substance which enters into its composition. 
 Various ideas have been formed as to the intimate nature of 
 
 this fibre. The opinion most generally admitted consists in 
 48 
 
368 GENERAL ANATOMY. 
 
 viewing the tissue of the bones as an areolar organic tissue 
 like the others, but containing earthy substance in extremely 
 narrow cavities, much in the same manner as water is inter- 
 posed in the tissue of a moist sponge. Others consider the 
 bone as an intimate mixture or a combination of gelatine and 
 phosphate of lime. Mascagni regards it as formed of absorb- 
 ent vessels filled with phosphate of lime. These hypotheses 
 however, do not rest upon any fact, or rather are in contra- 
 diction to facts. At the same time it is not known in what 
 exact proportion the earthy substance exists to the organic 
 substance of the bones. 
 
 585. Some tissues belong essentially to the organization of 
 the bones: these are the periosteum, the marrow, and the 
 vessels. y>*. 
 
 The periosteum is a very vascular fibrous membrane which 
 envelops the bone, as has already been seen (522.) 
 
 The medullary membrane is a very vascular cellular mem- 
 brane, which contains the marrow, and serves as an internal 
 periosteum to the bones (169 178.) 
 
 The blood-vessels of the bones, which are pretty numerous, 
 and of different volume, are distinguished into those which 
 first ramify in the outer periosteum, and then penetrate into 
 the small nutritious foramina of the compact substance; those 
 which penetrate, without ramifying, into the medullary canal, 
 where they are distributed to the membrane of that name, 
 and then penetrate through the inner surface into the compact 
 substance, where they communicate with the preceding; and, 
 lastly, into those which penetrate through the large and nu- 
 merous foramina of the short bones and spongy parts of the 
 long and broad bones, to be distributed in the spongy substance, 
 % and communicate there, in the long bones, with the vessels 
 of the two first orders. Some anatomists have given the names 
 of nutritious vessels of the first order to those of the medullary 
 canal of the long bones ; nutritious vessels of the second order, 
 to those of the spongy part; and of the third order, to those 
 which pass from the outer periosteum into the compact sub- 
 stance. In general, each of the nutritious canals contains an 
 artery and a vein. Those of the second order contain very 
 
OP THE BONES. 369 
 
 large veins, with very thin walls, which appear to consist only 
 of the inner membrane. These veins appear to have great 
 communication with the medullary cavities of the spongy sub- 
 stance. 
 
 Lymphatic vessels are seen at the surface of the large bones 
 only. 
 
 No other nerves are seen in the bones than those which ac- 
 company the vessels of the medullary membrane. 
 
 586. The great hardness of the bones depends upon their 
 chemical composition. Of all the organized parts, in fact, as 
 has been seen, they contain the greatest proportion of earthy 
 substance. It must have been known all along that the bones 
 are combustible, and that they leave an earthy residuum. It 
 has also long been known that the bones furnish gelatine or 
 glue by decoction. It was Scheele who announced that the 
 earthy part of the bones is phosphate of lime. A hundred 
 parts of fresh bone are reduced to about sixty by calcination. 
 
 According to the analysis of M. Berzelius, human bones, 
 deprived of water and fat, have the following composition: 
 animal matter reducible to gelatine by decoction, 32. 17; inso- 
 luble animal substance, 1.13; phosphate of lime, 51.4; carbo- 
 nate of lime, 11.30; fluate of lime, 2.0; phosphate of magne- 
 sia, 1.16; soda and muriate ef soda, 1.20. 
 
 Fourcroy and M. Vauquelin, in their first trials, did not find 
 phosphate of magnesia in human bones. According to M. 
 Hildebrandt, there is none of that substance in them. Accord- 
 ing to Dr. Hatchett, there is sulphate of lime in them, which, 
 according to M. Berzelius, is a product of calcination. Lastly, 
 Fourcroy and Vauquelin admit, moreover, in the bones, iron, 
 magnesia, silica, alumina and phosphate of ammonia, but no 
 fluate. 
 
 Besides the differences of composition dependent upon age, 
 individual constitution, and morbid affections, circumstances 
 which make the proportion of the animal substance and the 
 earthy substance vary, all the bones have not exactly the same 
 composition in the same individual. Thus the bones of the 
 skull generally contain a little more of earthy substance than 
 
370 GENERAL ANATOMY. 
 
 the others. The petrous portion of the temporal bone is of all 
 the parts that which contains most.* 
 
 587. The bones are of a yellowish white colour and opaque, 
 but it is especially by their hardness, their little flexibility, and 
 their resistance to rupture that they are remarkable, and it is 
 by these properties that they perform their part in the organ- 
 ism. However little flexibility and compressibility they pos- 
 sess, they are elastic. 
 
 They also possess a slow but real extensibility and power 
 of contraction. Thus the maxillar sinus, the nasal fossae, the 
 orbit, &c. are gradually enlarged by the development of tu- 
 mours in their interior. These cavities also return to their 
 previous state when they are freed of these causes of exten- 
 sion. The alveoli contract and become effaced after the loss 
 of the teeth, &c. 
 
 They possess no other kind of contraction. Sensibility ex- 
 ists in them only in the morbid state. Their power of forma- 
 tion is very remarkable in these two respects, that all the phe- 
 nomena\vhich belong to it, as their first formation, separation, 
 alterations of texture, &c. take place in a very slow manner, 
 while the faculties of reproduction and accidental production 
 are greater in them than in any other tissue. 
 
 588. The formation of the bones, ossification, or osteoge- 
 nesist is a phenomenon which has much occupied the attention 
 of observers, and which is, in fact, highly worthy of it. 
 
 * John Davy, in Monro's Outlines of the Anatomy of the Human Body. 
 Edinb. 1813. 
 
 -j- H. Eysson. de Ossibus infantis, cui tractatui annexus cst V. Colter, Os- 
 sium infantis historia, 12mo. Groning. 1659. Th. Kerkring-. Osteogenia 
 foetus. Lug-d. Bat. 1717. R. Nesbitt. The Human Osteogeny. Lond. 
 1736. J. Baster. De Osteogenia. Lug-d. Bat. 1731. A. Vater et Ulmann. 
 Osteogenia. Viteb. 1733. Albinus. Ann. Jicad. lib. vi. vii. Id. Icones Os- 
 sium Foetus Humani. accedit Osteogeniae brevis historia. Lugd. Bat. 1737. 
 Duhamel. Mem. de I'Jlcad. Roy. des Sc. 1739, 41, 43-46; Haller, Expe- 
 rimenta de Ossium formations in op. min. ii. Herissant, Mem. de tJLcad. 
 Roy. des 8c. 1768. C. Y. Senff. Nonnulla de. incremento ossium embryo- 
 nurn in primis graviditatis mensibus. Hals, 1801. J. Fr. Mcckel. Lent- 
 sckes JLrcliiv. fur die Physlolog. b. i. ii. 4. J. Howship. Expcr. and Observ. 
 
OF THE BONES. 371 
 
 The bones experience in their development, transforma- 
 tions so much the more remarkable, that the different states 
 through which they pass correspond to similar, but permanent 
 states, which are observed in animals. 
 
 After being fluid, like all the other parts, they become, first, 
 soft, mucous, or gelatiniform; secondly, cartilaginous, and 
 some of them fibrous and cartilaginous; thirdly, osseous. 
 
 The bones are mucous, transparent, and colourless, at a pe- 
 riod very close upon conception. They then grow by vege- 
 tation, and form a continuous whole which is subsequently 
 divided. 
 
 The cartilaginous bones, or temporary cartilages, do not 
 make their appearance until the end of the second month after 
 conception. This state can be perceived only in the bones or 
 the parts of bones which harden somewhat late, for it is doubt- 
 ful whether those which ossify at a very early period pass 
 through the cartilaginous state, a state which appears rather 
 destined to perform the functions of bones previously than to 
 be a period of ossification. y-f.Y v ,%$$? 
 
 The osseous state commences successively in the different 
 bones, from about a month after conception, in those which 
 ossify soonest, to about ten or twelve years after birth, in those 
 which are longest in becoming ossified. There are even cer- 
 tain accessory bony points which do not begin to form until 
 towards the fifteenth or eighteenth year. 
 
 589. The order in which the bones begin to appear and to 
 harden, has seemed capable of being reduced to rules. 
 
 Thus the clavicle and maxillae being very early in their de- 
 velopment, the sternum, the pelvis, and the limbs being later, 
 it has been said that the earliness is in relation to the import- 
 ance in the animal kingdom, or rather in the class of vertebrate 
 animals, where we in fact see, from the class of fishes upwards, 
 the clavicles and maxilla3 developed at a very early period, 
 
 on the Formation of Bone, in Med. Chir. Trans, vol. vi. Loncf. 1815. A. 
 Beclard. M6m. sur fOstiose, in Nouvcau Journ. de Med. vol. iv. 1819. 
 Serres. Des Lois dc tostcogenic, Analyse des trav. de TAcad. Roy. dcs Sc. 
 1819. 
 
372 GENERAL ANATOMY. 
 
 while the sternum, pelvis, and limbs are so in but a very small 
 degree. 
 
 It has also been established as a general proposition, that the 
 bones which are first formed are those which are near the san- 
 guineous and nervous centres, the ribs and vertebrae being in 
 fact developed at a very early period. 
 
 It has also been said, that the long bones appear first, then 
 the broad bones, afterwards the short bones; the clavicle, fe- 
 mur, and tibia appearing from the commencement, and the 
 bones of the tarsus and carpus at a much later period. 
 
 Lastly, It has been thought that the large bones ossify first 
 and the others successively. 
 
 There are many exceptions to these rules. 
 
 590. Ossification commences at the end of the first month 
 in the clavicle, and successively in the inferior maxillar bone, 
 the femur, the tibia, the humerus, the upper maxillary bone, 
 and the bones of the fore-arm, in which it commences about 
 the thirty-fifth day. It commences about the fortieth day in 
 the fibula, the scapula, and the palatal bones, and the follow- 
 ing days in the proral portion of the occipital bone, in the 
 frontal bone, the arches of the first vertebrae, the ribs, the great 
 wing of the sphenoid bone, the zygomatic process, the pha- 
 langes of the fingers, the bodies of the middle vertebrae, the 
 nasal and zygomatic bones, the ilium, the metacarpal bones, 
 the extreme phalanges of the fingers and toes, the condyles of 
 the occipital bone, and then in its basilar portion, in the 
 squamous portion of the temporal bone, in the parietal bone, 
 and in the vomer, in all which bones it commences about the 
 middle of the seventh week. In the course of the same week 
 it also commences in the orbitar wing of the sphenoid bone, 
 and lastly in the matatarsal bones, the phalanges of the toes 
 and the second phalanges of the fingers. In the ten following 
 days it commences in the body of the sphenoid bone, in those 
 of the first sacral vertebras, and in the ring of the tympanum. 
 About the middle of the third month it shows itself in the 
 costiform appendage of the seventh vertebra, before the end 
 of the third month, in the labyrinth, and towards the end ol 
 the same month, in -the ischium and inner pterygoid process ; 
 
OP THE BONES. 373 
 
 towards the middle of the fourth month, in the ossicula tym- 
 pani; at mid term, in the pubis, the calcaneum, the second 
 phalanges of the toes, the lateral masses of the ethmoid bone 
 and the turbinated bones of the nose; a little later in the first 
 pieces of the sternum; towards the sixth month, in the body 
 and odontoid process of the second vertebra, and in the lateral 
 and anterior masses of the first pelvic or sacral vertebra; a 
 little later still, in the astragalus; towards the seventh month, 
 in the sphenoidal turbinated bone; at a later period, in the 
 median ridge of the ethmoid bone; towards the period of birth, 
 in the os cuboides, the first vertebra of the coccyx and the 
 anterior arch of the atlas; a year after, in the coracoid bone, 
 the os magnum and os unciforme of the carpus, and in the 
 first cuneiform bone; about the third year, in the patella and 
 pyramidal bone; about the fourth year, in the third and second 
 cuneiform bones; about the fifth year, in the os scaphoides of 
 the tarsus, the trapezium and os lunare; towards the eighth 
 year, in the scaphoid bone of the carpus; a year after, in the 
 os trapezoides, and lastly, about the twelfth year, in the os 
 pisiforme. 
 
 591. Ossification does not everywhere result from the 
 transformation of cartilage into bone. The diaphysis of the 
 long bones and the centre of the broad bones, which are deve- 
 loped at a very early period, pass immediately from the .mu- 
 cous to the osseous state. The other parts of the system are 
 at first cartilaginous, and it is in them that the successive phe- 
 nomena of ossification may be best observed. 
 
 The cartilage, which for a longer or shorter period takes 
 the place, and performs the functions of the bone of which it 
 has the form and of which it gradually acquires the volume, 
 is at first hollowed with irregular cavities, then with canals 
 lined by vascular membranes filled with a mucilaginous or 
 viscous fluid; it becomes opaque, its canals become red, and 
 ossification commences towards its centre. 
 
 The first point of ossification, punctum ossificationis, al- 
 ways appears in the substance of the cartilage, and never at its 
 surface. It is surrounded by red cartilage at the place which 
 is in contact with it, opaque and full of canals at a little dis- 
 
374 GENERAL ANATOMY. 
 
 tance from it, and at a still greater distance homogeneous and 
 without vessels, but only perforated with some canals of blood- 
 vessels which tend towards the osseous centre. The osseous 
 point continually increases by growth at its surface, and also 
 by interstitial addition in its substance. The cartilage, suc- 
 cessively perforated by cavities and canals lined by sheaths of 
 blood-vessels, gradually diminishes in proportion as the bone 
 increases, and at length disappears. The canals of the carti- 
 lages themselves, which are very wide at the commencement 
 of ossification, become smaller and smaller, and at length dis- 
 appear when it is completed. In the place of a cartilage more 
 or less thick, but at first full or solid, without cavities and 
 without distinct vessels, at a later period perforated with ca- 
 nals lined by vascular and secreting membranes, there is found 
 a very vascular bone, full of areolar or spongy cavities, in- 
 vested with membranes and filled with adipose marrow. The 
 bone afterwards becomes less vascular as age advances. 
 
 592. The cause of ossification, like that of organic forma- 
 tion in general, is unknown. From Hippocrates and Aristotle 
 to Scarpa, Bichat, and Mascagni, a multitude of more or less 
 ingenious hypotheses have been proposed on this obscure 
 subject.* 
 
 It has been said, that the last divisions of the arteries ossify, 
 or are filled up with bony matter, and that after being filled 
 with bony matter, they burst, and allow it to escape around 
 them. It has also been said, and with more probability, that 
 they form, and allow to escape the ossifying matter, whether 
 by exhalent extremities, or by lateral porosities. But what 
 is this bony matter? Is it earthy substance? Where do the ar- 
 teries pour forth this substance? Is it in the interstitial areo- 
 laeof a cartilage, as has commonly been said since the time of 
 Herissant? or in absorbent vessels which are filled up, as Mas- 
 cagni alleged? These are so many mere hypotheses. All 
 that is known is this; that the vascularity greatly increases 
 before ossification, and that it always precedes that process; 
 that the cartilage diminishes and disappears in proportion as 
 
 * See Scemmering, De, Corporis. Hum.fabricfi, T. 1. DC Ossibus. 
 
OP THE BONES. 375 
 
 the bone forms and augments; and that the bone, which is 
 highly vascular at the period of its formation, becomes after- 
 wards less and less so. As to the state in which the bony sub- 
 stance is deposited, it is under the fluid form, and its successive 
 hardening depends either upon the continual addition of a 
 greater proportion of earthy substance, or upon the absorption 
 of the vehicle which gave it its fluidity. Ossification does not 
 depend upon the deposition of the earthy substance in an or- 
 ganic tissue, but upon the simultaneous formation of a tissue 
 containing at once both the animal substance and the earthy 
 substance. 
 
 The phenomena of ossification are different in the different 
 kinds of bones. 
 
 593. Ossification takes place at a very early period in the 
 long bones, commencing in them from one to two months af- 
 ter conception, according to the bone. Before the commence- 
 ment of ossification, no cartilages are observed in them. It is 
 the same also with them at the commencement of ossification; 
 there then being observed only a mucilaginous substance be- 
 tween the osseous cylinders. These osseous cylinders are at 
 first thick and short, whence results that they may elongate 
 greatly before growing thick. They correspond to the point 
 at which the principal medullary artery is afterwards perceived. 
 At the commencement of the third month, there are perceiv- 
 ed cartilaginous extremities at the end of these elongated bony 
 cylinders. Do these issue by vegetation from the interior of 
 the canal? These cartilaginous extremities have the same con- 
 formation as the extremities are to have at a later period; they 
 ossify, as has been said, in treating of ossification in general. 
 Most of them only ossify at the centre, and then form epiphy- 
 ses, which remain a greater or less time distinct at the ends of 
 the bones. In some of them ossification goes on from the 
 commencement, by the extension cf the body of the bone, in 
 the centre of their cartilaginous mass. 
 
 594. The broad bones of the skull begin to ossify between 
 
 the sixtieth and seventieth days. The pericranium and dura 
 
 mater are then very vascular. There exists between these 
 
 two membranes a mucous substance, which is itself very 
 
 49 
 
37G GENERAL ANATOMY. 
 
 vascular. The first bony points appear in the places which 
 are most full of blood-vessels, under the form of isolated grains, 
 afterwards disseminated and collected into net-works. They 
 then form a lamina thin at the middle, and furnished with ra- 
 diating bony fibres at the circumference. The surfaces of the 
 bone are covered, and the intervals between the radiating 
 fibres are filled up, by a reddish and very vascular mucilagin- 
 ous substance. The pericranium and dura mater are still very 
 red and vascular at that period. 
 
 595. The short or thick bones ossify in the same manner 
 as the extremities of the long bones. They are preceded in 
 their formation by cartilages which have the form, and ulti- 
 mately the volume of the bones which are to replace them. 
 These cartilages are at first homogeneous and full, and after- 
 wards present the successive changes already described: cavi- 
 ties, vascular membraneous canals, filled with viscous fluid, and 
 bony points which extend from the centre to the circumference. 
 
 The patella and sesamoid bones are formed in a tissue which 
 is at first fibrous, then cartilaginous, and in the same manner 
 as the short bones. 
 
 The mixed bones, are intermediate in their formation, as 
 they are in their external figure, and internal conformation, 
 between the bones of the two different classes. 
 
 596. Many bones are formed by several distinct points of 
 ossification. 
 
 Several median bones, whether broad or thick, are formed by 
 two lateral parts, which afterwards unite in the median line. Of 
 this kind are the arches of the vertebrae, the frontal bone, the 
 body of the sphenoid bone, the squamous portion of the occi- 
 pital bone, the inferior maxillar bone, and the middle pieces of 
 the sternum. But in several of the median bones also, ossifi- 
 cation commences at the middle, and extends towards the 
 sides, as in the body of the vertebrae, the basilar portion of 
 the occipital bone, the crest of the ethmoid bone, the body of 
 the hyoid bone, and the first and last bones of the sternum, 
 whether the bone is formed of two lateral portions at an earlier 
 period, at the period of its conversion into cartilage, for exam- 
 ple, or whether it be originally single. 
 
OP THE BONES. 377 
 
 Many bones, broad as well as short, are formed of several 
 principal or original points of ossification, which unite more 
 or less quickly. Frequently these points correspond to dis- 
 tinct bones in other genera or classes of animals. Of this kind 
 are the points of ossification of the vertebrae, the occipital bone, 
 the sphenoid bone, the temporal bone, the maxillary bone, the 
 sternum, the coxal bones, the sacrum, &c. There even occurs 
 in the ruminating animals an example of the collateral union 
 of two long bones to form the cannon bone. 
 
 597. Lastly, a great number of bones, especially of long 
 bones, and some broad and short bones, have accessory or se- 
 condary points of ossification, which are called epiphyses* on 
 account of their being implanted upon the body of the bone, 
 by means of a cartilage which lasts for a longer or shorter pe- 
 riod. The large long bones of the thigh, arm, leg, and fore- 
 arm, have at least one epiphysis at each extremity. 
 
 The clavicle, the metacarpal, metatarsal and phalangeal 
 bones, have epiphyses at one extremity only. 
 
 Of the broad bones, the coxal bones, and the scapulae, have 
 marginal epiphyses analogous to these terminal epiphyses of 
 the long bones. The ribs have epiphyses at their dorsal extre- 
 mity, and at their tubercle. 
 
 Of the short bones, the vertebrae are almost the only ones 
 that have epiphyses; they have them at the two faces of their 
 body, and at the summit of all their processes which are not 
 articular. Of the other short bones, the calcaneum is the only 
 one that has an epiphysis. It is situated at its posterior extre- 
 mity. 
 
 The epiphyses begin to form at very different periods, from 
 about fifteen days before birth, to fifteen or eighteen years 
 after, and remain for a longer or shorter time distinct before 
 uniting with the body of the bone. The periods at which they 
 unite are comprehended between the fifteenth and twenty-fifth 
 year. Of all the epiphyses, the one which ossifies first, is that 
 of the lower extremity of the femur, ossification commencing 
 
 * Plainer. De Ossium Epiphysibus, 1736. Ungebauer. Epistola dc 
 Ossium trunci carp. hum. Epiphysibus Sero Onsets carundemquc Genesi. Lips. 
 1739. Beclard, foe, cit. 
 
378 GENERAL ANATOMY. 
 
 in it previous to birth; and it is one of the latest in being united 
 to the body of the bone. That of the upper extremity of the 
 radius, which is one of the last to ossify, is perhaps, on the 
 contrary, the one which is soonest in uniting. 
 
 598. The growth of the bones takes place in an evident 
 manner, by the successive addition of new bony substance 
 around that which was first formed. 
 
 The growth in length occurs by the elongation of the 
 body of the long bones at their extremities. For this purpose, 
 the ends of the bony cylinder are covered with bony filaments 
 or villosities immersed in the not yet ossified extremity, hol- 
 low and vascular, which continually elongate, becoming more 
 and more slender as the vessels ramify more, and as the ossi- 
 fication slackens. At the same time, the cartilaginous extre- 
 mities, commencing at the centre, are gradually transformed 
 into bones which constitute epiphyses. 
 
 The growth in breadth takes place, in the flat bones, in the 
 same manner, whether by the successive addition of bony sub- 
 stance in the edge of the bone, as in the bones of the skull, or 
 by the osseous formation, under a marginal epiphysis, which 
 covers its edge, as in the scapula and coxal bone. 
 
 The growth in thickness occurs in all the bones in the 
 same manner. The periosteum, which until this period is very 
 vascular, secretes and deposits between its fibres, at the sur- 
 face of the bone, osseous substance, at first mucous, then hard, 
 which being thus successively added to the surface, increases 
 the thickness of the bone. 
 
 599. 'The growth of the prominences of bones takes place 
 in the same manner as that of the long bones furnished with 
 epiphyses, that is to say, between the body of the bone and 
 the base of the eminence; as in the trochanters, &c. In others, 
 it is at the surface itself that the growth occurs, precisely 
 in the same manner as the growth in thickness of the bones. 
 Most of the eminences grow in this way. As to the hollow- 
 ing of the external cavities which are not articular, it is in 
 many places determined by pressures, which without really 
 depressing the bone, nevertheless produce a depression of it; 
 
OF THE BONES. 379 
 
 by rendering its nutrition less active than in the surrounding 
 parts. 
 
 The articular eminences and cavities are moulded upon each 
 other. This is also the case with the cavities destined to lodge 
 soft or fluid parts, and the medullary cavities of the bones. 
 Their existence and form are greatly dependent upon those 
 parts which they contain. Thus the conformation of the 
 skull, and that of the vertebral canal depend greatly upon 
 that of the nervous centre which they lodge. The lower part 
 of the vertebral canal, when empty, is triangular, just as the 
 cotyloid cavity becomes when the head of the femur has been 
 for a long time removed from it, both these parts being formed 
 of three bony points. 
 
 600. Be this as it may, the termination of evident growth, 
 in length and breadth, depends upon the uniting of the long 
 bones with their terminal epiphyses, and of the broad bones 
 with their marginal epiphyses, or with each other. The ter- 
 mination of the growth in thickness depends upon the cessa- 
 tion of the osseous formation at the surface of the bones. This 
 last kind of growth continues somewhat longer than the first. 
 
 The growth of the bones nevertheless continues to take 
 place, but locally, and in an insensible manner, although some- 
 times in a manner which is still pretty sensible. 
 
 The sensible growth depends upon a kind of juxta-position 
 at the extremities, edges, and surfaces of the bones. The in- 
 sensible growth, on the contrary, is interstitial, and depends 
 upon a true intus-susception. Striking examples of the latter 
 are seen in some morbid cases especially; in empyema, spina- 
 ventosa, &c. 
 
 601. The growth being terminated, the bones remain the 
 seat of a habitual supply or nutrition. Deposition and ab- 
 sorption go on very slowly and in an insensible manner in 
 them in the state of health, and especially in old age. But in 
 certain cases of disease, very decided changes take place in 
 the properties of the bones, which clearly show that changes 
 not less great are operated in their composition. 
 
 602. The facts relative to the growth and habitual nutri- 
 
380 GENERAL ANATOMY. 
 
 lion of the bones, are especially proved by the effects of mad- 
 der upon them. 
 
 Mizauld first,* and Belchiert a long time after, were the first 
 who observed that when madder (Rubia tinctorum,} is given 
 to animals mixed with their food, their bones become red. 
 Duhamel, Boehmer,| Detlef, J. Hunter, || and several others 
 have made curious experiments on the same subject. Ruther- 
 fordll has explained the effect of madder on the bones alone, 
 and to the exclusion of all the other parts of the body, by a 
 chemical affinity of the colouring matter of madder for the 
 earthy substance of the bones. 
 
 Duhamel found, in his experiments, that the bones of young 
 animals are coloured much sooner than those of old animals; 
 that the progress of their tincture and ossification is so much 
 the more rapid the more vigorously their growth goes on; 
 that when the madder is discontinued, the bones become 
 white again, and that the return to their original colour is 
 effected by the superposition of white layers upon the red. 
 This last fact is also fully demonstrated by Hunter's experi- 
 ments. Duhamel, however, imagined, notwithstanding these 
 decisive experiments, that the bones enlarge in thickness by 
 extension. 
 
 As to the growth in length, Duhamel's experiments also led 
 him to think that this growth, which he compares to vegeta- 
 tion, takes place by the extension of their parts. It is proba- 
 
 * Ant. Misaldus. Centitr. MemorabiKum seu arcanorum omnis generis, 
 1572. 
 
 fPhilos. Trans, vol. xxxix. 1736. 
 
 + Radicis rubise tinctorum affedus in Corp. JLnim. Lips. 1751. Ejusdem 
 prolusio, qua callum ossium a rubias tinctorum radicis pastu infectorum descri- 
 bit. Ibid, 1752. 
 
 Osrium calli generatlo et natura perfrada in animalibus rubise, radiee 
 pastis, ossa demonstrate!. Goet. 1753. 
 
 U Exper. and observ. on the growth of bones, from the papers of the late 
 Mr. Hunter, by Ev. Home, in Trans, of a Society for Improvement, &c, 
 vol. ii. Lond. 1800. 
 
 \Bisput. Med. Inaug t de Dentium Formaiionc d StrudurA, &c. Auct.R, 
 Blake. Edinb. 1798. 
 
OP THE BONES. 381 
 
 bly so in slow and insensible growth, but the rapid elonga- 
 tion which takes place before the epiphyses become united, 
 evidently depends upon an addition of bony substance to the 
 end of the body of the bone, as is proved by the following 
 experiment of Hunter's. The tibia is. laid bare in a young 
 hog, and perforated at the two extremities of the ossified body, 
 the interval between the two holes being carefully measured. 
 Some months after, when the growth has advanced, the same 
 distance is found to exist between the two bones, and all the 
 elongation that has taken place has been beyond the hole, at 
 the extremities of the diaphysis. 
 
 These experiments, which leave little to be desired with 
 respect to the growth of the bones, do not by any means afford 
 results so satisfactory respecting the habitual nutrition of the 
 bones. To redden the bones of a young animal, it is sufficient 
 to give it a few drams of madder, during a period of some 
 days, while the same substance given in greater quantity, and 
 during weeks or months, to an adult animal, hardly imparts 
 any colouring to them. 
 
 603. After the growth in extent has ceased, the bones still 
 undergo farther changes, the most remarkable of which is their 
 decrease.* The medullary canal of the long bones continues 
 to increase in diameter from the moment of their formation. 
 So long as the growth in thickness continues, the walls of the 
 canal being augmented at the exterior, preserve their thick- 
 ness, and even increase in that direction. 
 
 Duhamel made a very curious experiment on this subject, 
 although he drew false inferences from it. Having laid bare 
 and surrounded with a metallic wire a long bone of a young 
 animal which he killed some time after, he then found the 
 wire covered over by the bone which had increased in thick- 
 ness, and the canal, having acquired the diameter of the metal- 
 lic ring, he concluded from this circumstance that the bone 
 had enlarged by expansion, by the widening of its canal. This 
 is not the case, however. The bone had increased at its ex- 
 
 * Albinus. JLnnot. Acad. F. Chaussard. Hccherchcs sur I 1 'organ, des vicil- 
 lards. Paris, 1822. 
 
382 GENERAL ANATOMY. 
 
 terior by addition, and diminished at the interior by abstrac- 
 tion, whence resulted the enlargement of the canal. 
 
 In fact, when the growth of the bone in thickness is accom- 
 plished, the canal continuing to enlarge by internal absorption, 
 its walls become thin in a singular degree, insomuch that, 
 after having been thicker in the child than the diameter of the 
 canal, and in the adult nearly as thick, they present in old age 
 but a very small fraction of that diameter. The spongy cavi- 
 ties of the short bones, of the broad bones, and of the extremi- 
 ties of the long bones, generally enlarge in the same manner, 
 so that, by this diminution of the substance of the bones, the 
 skeleton of aged persons is rendered much lighter than that of 
 others. 
 
 The broad bones of the skull pretty frequently undergo a 
 diminution in thickness of another kind in old age. It results 
 from the absorption of the diploe, and the approximation of 
 the outer table to the inner, so as to produce at the same time 
 a great diminution of thickness and an external depression. 
 It is in the parietal prominences which are frequently affected 
 by it, that this wasting generally commences. 
 
 Frequently also, in old age, the articular surfaces of the 
 bones of the inferior members and the faces of the vertebrae 
 are widened and flattened, as if they had at length yielded to 
 pressure. 
 
 604. The form of the bones is not the only property that 
 undergoes changes from the advance of age. Their consistence 
 also exhibits remarkable changes; the bones of children are 
 more flexible and less brittle than those of adults, and may be 
 bent or twisted in the living subject without breaking. Those 
 of old persons, on the contrary, are denser, harder, and more 
 brittle than those of adults, which circumstances, added to 
 their having become thinner, renders fractures very common 
 in old age. There is also a sensible difference in the proportion 
 of the earthy substance, it being greater in old age than in the 
 adult state. 
 
 Thus, after the growth in dimensions has terminated, the in- 
 crease of the density continues in the bones, as in all the other 
 parts of the body. 
 
OF THE BONES. 383 
 
 605. Accidental ossification* is of very frequent occur- 
 rence, and was known at a very early period. This ossifica- 
 tion is rarely perfect, and may in this respect be distinguished 
 into several varieties. 
 
 The least perfect kind of accidental ossification is called 
 earthy. It produces a white, opaque, chalky, soft, friable, and 
 even sometimes semi-fluid substance. It is composed of ani- 
 mal matter, in small proportion, and earthy substance, and is 
 commonly met with in cysts. Phlebolites are sometimes 
 of this kind. It also occurs in isolated and formless fragments, 
 in abscesses, in the lungs, in the fibrous body of the uterus, in 
 the cellular tissue, and in the ligaments of persons affected 
 with gout, in the brain, &c. Lastly, it is frequently met with 
 infiltrated in the bronchial glands, the lungs, the liver, the 
 kidney, the heart, &c. 
 
 The stony accidental ossification is of very frequent occur- 
 rence. It is very hard, opaque, and contains a greater pro- 
 portion of earthy substance than the bones in their natural 
 state. It is often met with under the form of a more or less 
 thick incrustation under the serous membranes, in the proper 
 membrane of the spinal marrow, and especially in the walls 
 of the arteries. It also occurs under the form of cysts. It is 
 observed under the form of isolated masses in the fibrous bodies 
 of the uterus which have been ossified, and in the pineal gland, 
 where it constitutes the substance called acerbulus. It is also 
 sometimes met with under the form of infiltration of the pan- 
 creas. What has been described under the name of petrifac- 
 tion of certain organs, or of the foetus, is nothing else than an 
 infiltration of very compact stony bone, so as to cause the ani- 
 mal matter of the organ to disappear almost entirely. 
 
 The accidental production sometimes differs still more from 
 the bones, resembling in hardness and polish the enamel of 
 the teeth. This accidental enamel sometimes replaces certain 
 diarthrodial cartilages. 
 
 Accidental ossification sometimes greatly, or entirely, re- 
 
 * J. Van Heckeren. De osteogenesi pr&ternaturaK. Lugd. Bat. 1797. 
 P. Rayer. Mem. sur F ossification morbidc, in Archives Gtntr. de M?d. t. i, 
 Paris, 1823. 
 
 50 
 
384 GENERAL ANATOMY. 
 
 sembles the natural bone, in its periosteum, its medullary 
 spongy cavities, its texture, its semi-transparency, and its che- 
 mical composition; but this perfect production is of rare oc- 
 currence. It has been met with under the form of an isolated 
 body in the dura mater. I have also seen it, but almost en- 
 tirely compact, under the form of laminae, situated in the an- 
 terior vertebral ligament. The bony plates which cover the 
 costal cartilages are of the same nature. There is also some- 
 times observed a perfect, but compact, ossification, under the 
 form of the hydatiferous cyst. 
 
 Accidental ossification, which also presents several varieties, 
 is often an effect of age. Many old persons, however, are not 
 affected with it. Its causes are most commonly irritation 
 and chronic or latent inflammation. It is more frequent in 
 cold than in warm countries. It commences with a plastic 
 production, and sometimes passes through the semi-cartilagin- 
 ous or fibrous states, but at other times does not. In general, 
 it produces no inconvenience except by its bulk or mechanical 
 effects. 
 
 The transformation of permanent cartilages into bone may 
 be regarded as intermediate between natural and accidental 
 ossification. 
 
 606. Exostosis* is also an accidental bony production, 
 sometimes perfect, and often stony, and resembling ivory. 
 The periosteum being irritated or inflamed, there takes place, 
 at its inner surface, in its substance, and in a part of greater 
 or less extent of its breadth, a deposition of soft, organizable 
 matter; it constitutes periostosis, which terminates variously. 
 In many cases it ossifies, constituting at first a kind of epiphy- 
 sis or bone, distinct and separable from the natural bone, to 
 which the exostosis is at length firmly attached. Sometimes it 
 consists of a very circumscribed nodus, which has been rapid- 
 ly developed. At other times it forms slowly, and consists 
 of a voluminous and foliated mass. Sometimes, also, a whole 
 limb, or even a larger portion of the skeleton is affected by it. 
 
 Spina-ventosa, in place of always consisting of a morbid 
 
 * On Exostosis, by M. A. Cooper, in Surgical Essays, Part I. Lond. 1818. 
 
OF THE BONES. 385 
 
 production, is sometimes formed of organizable substance, 
 which after having distended and dilated the natural bone, 
 at last ossifies more or less completely in its interior. 
 
 607. When a bone is denuded of the periosteum,* if the 
 subject is young, if the bone itself be not altered, and if it has 
 not remained long uncovered, the wounded soft parts, if re- 
 stored to their natural position, unite by first intention. 
 
 Under contrary circumstances, and in those in which the 
 inflamed periosteum separates from the bone by suppuration, 
 in that in which it becomes gangrenous, and when the peri- 
 osteum suppurates or mortifies, &c. the bone, deprived of its 
 nutritive apparatus, becomes affected with necrosis at its sur- 
 face, and to a greater or less depth. The living part in the 
 vicinity of the dead portion, becomes inflamed, softens, is at 
 length detached from the part affected with necrosis, and sup- 
 purates. The dead portion having thus become free, falls off. 
 The subjacent granulations at length produce a cicatiix which 
 covers the bone, adheres to it, and forms a new periosteum. 
 
 608. After amputation,t matters go on in one or other of 
 the two ways above described. 
 
 When the bone and its nutritive apparatus have not been 
 hurt above the amputated place, and especially when the union 
 of the wound is immediate, the end of the bone commonly 
 unites by first intention with the soft parts. 
 
 On the contrary, when the wound remains open and sup- 
 purates, when the periosteum has been torn or detached above 
 the place of amputation, or when the medullary membrane 
 has been irritated and inflames, the end of the bone becomes 
 affected with necrosis, and there is detached a slice compre- 
 hending its whole thickness, and generally gaining obliquely 
 upon its outer surface, because the periosteum is commonly 
 more injured, or is injured higher than the medullary mem- 
 brane. 
 
 * Tenon. Three Memoirs on Exfoliation of the Bones, in Mem. et Obt. 
 sur TJLnaL Pathol et la Chir. &c. Paris, 1816. 
 
 f Van Home. Dissertatio deiis, quse inpartibus membri, preesertim osseis, 
 amputations vukieratis, notanda sunt. Lugd. Bat. 1803. L. L. Brachet, 
 Mtm. de Phys. Path, sur ct que devient k fragment de Pos apres une Amputa- 
 tion, in Sullet.de la Soc. Med. d> Emul de Paris, 1822. 
 
386 GENERAL ANATOMY. 
 
 In both cases, moreover, the end of the bone ultimately un- 
 dergoes other changes. In general, it becomes greatly di- 
 minished in volume and weight. The canal, which is at first 
 filled by the spongy rarefaction of the compact substance, is 
 re-established, but is closed at the extremity by a bony pro- 
 duction placed over it like a lid. 
 
 609. Deep necrosis* of the long bones presents at the 
 same time interesting phenomena of separation and osseous 
 production. 
 
 When the medullary membrane of a long bone is destroyed 
 in a living animal, by introducing into its canal a foreign body 
 which tears or cauterizes it, the whole limb to which the bone 
 belongs swells, becomes painful, and has its temparature in- 
 creased. At a later period abscesses form, which open and 
 remain fistulous. There is seen, or felt through the openings, 
 a moveable bone in the midst of the pus, and contained in 
 another bone which is hollow. The internal bone, which be- 
 comes in time more and more loose, sometimes gets engaged 
 by one of its extremities in one of the apertures of the external 
 bone, and is even at length expelled. It is then seen to have 
 the length of the diaphysis of the original bone, and a variable 
 thickness, but which sometimes entirely equals that of the 
 original bone. The new bone, however, being freed of the 
 foreign body, and being connected from the commencement 
 with the extremities of the old bone, which are now become 
 its own extremities, gradually contracts within itself. The 
 suppuration diminishes, and at length entirely ceases, when 
 the walls, which have approached each other to such a degree 
 as to touch, are agglutinated together, and at length become 
 entirely confounded. 
 
 * Chopart and Robert. De JVecrosi Ossium Theses Jlnatomico-Chir. 
 Parisiis, 1766. Troja. De Novorum Ossium, &c. Paris, 1775. Blumen- 
 bach, in Richter, Chir. Biblioth. B. VI. David. Observ. sur une Maladie 
 Connue sous le nom de necrose. Koeler. Experimenta circa regenerationem 
 ossium. Getting. 1786. J. P. Weidmann. De Necrosi Ossium. Franc, ad 
 Mcen. 1793, fol. Russel. Practical Essay on a Certain Disease of the 
 Bones called Necrosis. Edinb, 1794. A. H. Macdonald, de Necroiti ac 
 calk. Edinb. 1799. Macartney, in Crowther's Pract. Obs. on the Diseases 
 of the Joints. Lond. 1808. Charmeil, DC la Regeneration des Os. Metz. 1821. 
 
OP THE BONES. 387 
 
 The new bone, which is at first very soft and flexible, to 
 such a degree as sometimes to be bent by the action of the 
 muscles, when the old bone, engaged by one extremity in one 
 of the fistulous openings, no longer forms a solid support to 
 it, ultimately acquires and preserves a density and hardness 
 superior to those of the original bones. 
 
 The medullary cavities form in the new bone in proportion 
 as its tissue, which is at first uniformly lax, acquires density 
 at the exterior. 
 
 All these changes take place as if spontaneously in the hu- 
 man species, in circumstances and under the influence of causes 
 which appear to act upon the periosteum to produce inflamma- 
 tion in it, and probably also upon the medullary membrane, 
 that is to say, upon the internal nutritive apparatus, in such a 
 manner as to alter its texture and functions. 
 
 The long bones, in which necrosis occurs most frequently, 
 are the following, being arranged nearly in the order of their 
 frequency: the tibia, femur, the humerus, the mandibular 
 bone, the bones of the fore-arm, the clavicle, the fibula, and 
 the bones of the metatarsus and metacarpus. 
 
 Two theories have been proposed on this subject, the au- 
 thors of which have only erred in making them exclusive, for 
 things sometimes take place in the one way and sometimes in 
 the other. 
 
 Troja, David, Bichat, and many others, have admitted that 
 the sequestrum is formed by the entire body of the original 
 bone rendered more or less thin by absorption and by the sol- 
 vent action of the pus, and that the new bone results from a 
 new formation, of which the external nutritive apparatus, that 
 is to say, the periosteum and its vessels, has furnished the ma- 
 terials, which being deposited in its substance, and especially 
 in its internal surface, have passed through all the states of 
 fluidity and successive hardening which the regular bones 
 present, excepting that the bony hardening commences in 
 many points at once. 
 
 Experiments made on living animals show, that when the 
 periosteum is torn off, it is reproduced along with the bone; 
 
388 GENERAL ANATOMY. 
 
 but the hardening of the latter is retarded during the whole of 
 the time necessary for the reproduction of its vascular envelope. 
 
 When things have thus occurred, i. e. when it is a new bone 
 that is formed, the separated piece has the same volume and 
 appearance as the original bone, presenting the same processes, 
 impressions, lines, and inequalities. 
 
 Other pathologists, and in particular MM. Leville, Riche- 
 rand, and recently Dr. Knox,* maintain that in all cases, 
 the necrosis in question is confined to an internal portion of 
 the substance of the walls of the medullary canal, and that the 
 new bone simply results from the outer part of the original 
 bone which the necrosis has not affected, and which has only 
 undergone changes of volume and consistence. 
 
 It is certainly so in many cases, and then the sequestrum 
 has a diameter sensibly less than the original bone, and its sur- 
 face is rough and uneven. 
 
 The extremities of the long bones become affected with ne- 
 crosis, and are reproduced much less frequently than their bo- 
 dy. It is hot uncommon, however, to observe these pheno- 
 mena at the upper extremity of the humerus. They have also 
 been observed at the lower extremity of the bones of the fore- 
 arm. I have extracted from the interior of a new bone the 
 lower extremity of the tibia, which had become affected with 
 necrosis after a fracture which happened two or three years 
 previously. The articular cartilage was all that was wanting 
 at this extremity. 
 
 The broad bones are also subject to necrosis, but their re- 
 production is rare or imperfect. The scapula, however, after 
 being affected with necrosis, has been seen to be replaced by 
 two other bones. 
 
 Necrosis of the short bones is much more common than is 
 supposed. It commonly exists under the form of a seques- 
 trum inclosed at the centre of the bone. This constitutes many 
 of the alleged cases of caries of the bones of the tarsus, car- 
 pus, &c. 
 
 * Edinburgh Medical and Surgical Journal, 1822 and 1823. 
 
OF THE BONES. 389 
 
 610. The bony substance of new formation by which the 
 solutions of continuity in bones are united, is named callus.* 
 
 When a long bone is fractured, besides the rupture of the 
 osseous substance, there takes place a rupture of the medullary 
 membrane, and commonly also of the periosteum, as well as of 
 the vessels of these membranes and of the bone. There re- 
 sults from these vascular and other divisions, a more or less 
 considerable effusion of blood around and in the interval of the 
 fragments. If the latter are kept in perfect contact, an agglu- 
 tination is presently effected between them and between the 
 other divided parts. There also supervene a swelling and dis- 
 tention of the soft parts that have been divided and of those 
 which surround them, which become compact like inflamed 
 cellular tissue. The marrow, at the place of the fracture, es- 
 pecially participates of this state. All these parts, and espe- 
 cially the agglutinating or organizable substance which dis- 
 tends them, successively ossify, and form at the exterior a bony 
 ring of greater or less extent, the thicknessof which diminishes 
 from the centre or from the seat of the fracture towards the 
 two extremities, and at the interior a fusiform bony mass. The 
 bone, however, of which the two fractured portions are thus 
 brought together, seems until now to be in no degree affected 
 by the changes which are taking place around it. It is only 
 from this period, and in proportion as these temporary external 
 and internal ossifications diminish and disappear by absorption, 
 that the agglutination of the fragments becomes converted into 
 a permanent bony union. 
 
 Several pathologists, and in particular Bonn, Callisen, and 
 J. Bell, have contented themselves with observing the facts 
 without attempting to explain them. Numerous hypotheses, 
 however, have been proposed for the explanation of these re- 
 markable phenomena. Boerhaave, Haller, and Detlef, his dis- 
 
 * Duhamel, Mem. de PJlcad. Roy. des Sc. Paris, 1741. Boehmer, De 
 Ossium callo, Lips. 1748. P. Camper, Observationes circa callum Ossium 
 Fractorum, in Essays and Observ. Phys. and Liter, vol. iii. Ediri. 1771. 
 Bonn, De Ossium Callo, &c. Amstel, 1783. Macdonald, op. cit. J. How- 
 ship, in Med. Chir. Trans, vol. ix. Lond. 1816. Breschet, Quelques Recher- 
 ches Hist, et Experim. sip k cal. Paris, 1819. 
 
390 GENERAL ANATOMY. 
 
 ciple, have admitted that the fragments are united by a gluti- 
 nous or coagulable matter. 
 
 J. Hunter, Macdonald, and Howship, have thought that this 
 organizable and agglutinating matter is furnished by the blood. 
 It is well known that Duhamel and Fougeroux have admit- 
 ted that the periosteum furnishes a bony ring which unites the 
 fragments. Blumenbach has given the figure of a human bone 
 surrounded by a ring of this kind. M. Pelletan taught the 
 same thing in his clinical lectures. Camper had observed that 
 there are an external callus and an internal callus. Bichat, 
 M. Dupuytren, M. Cruveilher, and others, have admitted that 
 these external and internal ossifications are provisory. 
 
 Many pathologists,and especially Bordenave, Bichat, Riche- 
 rand, Scarpa, &c. have maintained that the union of divided 
 bones is effected by cellular and vascular granulations, like that 
 of the soft parts, which is true in either case only where the 
 division is external and suppurative, and not when it takes 
 place, as well as the union, without external wound and with- 
 out suppuration. 
 
 1 have already elsewhere* remarked, that all that these hy- 
 potheses want, in order to be theories or exact expression of 
 facts, is to be combined, or not to be exclusive. This was 
 Troja's opinion, and is also that of M. Boyer, M. Delpech, &c. 
 In fact, in the uniting of a simple fracture, there take place 
 in succession, agglutination of the fragments by an organizable 
 fluid, the materials of which are furnished by the blood; ossi- 
 fication of a similar substance, infiltrated all round the frac- 
 ture, both internally and externally; lastly, vascular and osse- 
 ous union between the fragments themselves. 
 
 The periosteum, which, when it exists, appears to perform 
 so important a part in the production of the callus, is no more 
 indispensable here than in the reproduction after necrosis. It 
 has been removed from the ends of fractured bones in birds, 
 and has been reproduced at the same time that the callus 
 formed. 
 Comminuted fracture of the long bones, and especially that 
 
 * A. Beclard, Propositions sur quelques Points dc la Alcdecine, Paris, 1813. 
 
OP THE BONES. 391 
 
 % 
 
 which is produced by fire-arms, is accompanied, in its union, 
 by a large and permanent osseous production. It is in this 
 production especially, in the same manner as in exostosis, as 
 well as in reproduction after necrosis, that a great mass of new 
 osseous matter may be seen. After being fluid it becomes solid, 
 soft, flexible, and elastic, so that it might almost be mistaken 
 for cartilage. But this substance contains numerous bony 
 points; and if the observation is made in an animal that has 
 taken madder, it is found to be of a rose colour, or even red, 
 which is never the case with cartilages. It afterwards becomes 
 hard like a common bone, and even more so. This permanent 
 bony tumour bears the name of callus. 
 
 611. Wounds of the bones differ from fractures, in the 
 state of the solution of continuity itself, and in its mode of 
 reparation, which is different from that described above. The 
 bony tissue being very hard, and possessed of little flexibility, 
 a sharp instrument which cuts it obliquely really produces a 
 multitude of small fractures in the fragment which it raises, 
 just as happens to a chip of dry wood raised by the blow of a 
 hatchet As to the subsequent union of this cut, as that of a 
 fracture with wound, it commonly does not take place until 
 after an exfoliation, and by the formation of suppurating granu- 
 lations. 
 
 612. The loss of substance of the long bones, in young and 
 healthy subjects, is followed by a more or less extensive, and 
 sometimes complete reparation or production. In birds,* the 
 periosteum may even be removed, together with a large por- 
 tion of one of the bones of the fore-arm, and these parts are in 
 time reproduced by a kind of vegetation of the t\vo ends. In 
 the human species, when the loss of substance of a bony cylin- 
 der is inconsiderable, and the disposition of the parts does not 
 admit of the fragments being brought together, there is pro- 
 duced, by the sinking and elongation of the ends, a cartilagini- 
 form fibrous substance, which does not acquire the hardness 
 of bone in its whole extent. 
 
 These more or Jess advantageous results of the reproduction 
 
 * Charmeil. Op. Cit. 
 . 51 
 
33S GENERAL ANATOMY. 
 
 of a portion of bone that has been removed, have given rise to 
 the practice, in certain cases, of cutting out portions of diseased 
 bones in their state of continuity.* 
 
 613. When the callus after having commenced is subjected 
 to repeated motions of flexion, twisting, distention, &c. it re- 
 mains flexible, as in the preceding case, or no union takes place 
 at all, and the ends of the bones remain in contact. This is 
 also the case when the ends of bones are separated by a slight 
 layer of muscular tissue. 
 
 614. The broad bones have a stronger power of reparation 
 and reproduction than the long bones. After the bones of the 
 skull have been trepanned, a production is formed which is sel- 
 dom bony to the centre. After the same operation, if the se- 
 parated bony operculum is reapplied, it sometimes unites. t 
 The phenomena of reproduction are very imperfectly known 
 in the short bones. 
 
 615. The separation of the epiphysesj takes place, in 
 young subjects, from mechanical causes, like fractures, and the 
 parts thus separated unite again by means of a similar callus. 
 Chronic inflammation of the joints of the long bones also some- 
 times, in children and young persons, causes the separation of 
 their epiphyses, which are not yet united. Both of these 
 kinds of separations are rare. A case of false joint, in conse- 
 quence of the fracture of the neck of the femur, has lately been 
 published as an example of separation of the epiphysis in an 
 adult. 
 
 616. When an aneurismal tumour meets with a bone in 
 the course of its development, the latter is gradually destroyed 
 in the place which is in contact with the tumour, without any 
 residuum of its substance remaining. This destruction bears 
 the appellation of wearing of the bones. 
 
 617. The morbid anatomy of the bones has already given 
 
 * Roux, De la Resection, &c. Paris, 1812.Champion, De la Resection 
 des os dans leur continuity. Paris, 1815. 
 
 f Merrem, Mmadversiones, quaedam, &?c. Giess. 1810. 
 
 $ Reichel, De Epiphysium ab ossium diaphysi diductione. Lips. 1769. 
 
 A. Bonn. Descriptio Thetauri Ossium Morbosorwn Hoviani. Amstel. 
 1783. Ed. Sandifort, Museum Anat. Acad. Lugduno~af.avae. Lugd. Bat. 
 
OP THE BONES. 393 
 
 rise to numerous works and engravings. It still, however, 
 presents, on some points, many obscurities to be cleared up, 
 which, perhaps, depend more than is imagined upon vague 
 comparisons which have been made between the alterations of 
 the bones and those of the soft parts in general, without speci- 
 fying any tissue in particular. It is a point of anatomy and 
 pathology which is highly worthy of attention. 
 
 6 IS. Original vices of conformation* are rare in the long 
 bones; less so in the short bones; frequent in the broad bones; 
 rare in the bones of the limbs; more frequent in those of the 
 trunk, especially in the sternum and ribs; still more so in the 
 bones of the head ; and especially in those of the cranium ; and 
 more so in those of the arch than in those of the base. 
 
 The most common variations are observed in the reunions 
 of the bones, then in their figure, then in the form of their 
 holes, and, lastly, in their apophyses. 
 
 Most of these vices of conformation, like those of all the 
 parts, appear to depend upon a defect of formation. Some of 
 them, however, seem to depend upon an excess of formation. 
 They are of rare occurrence in the bones and in the parts of 
 bones which are first ossified, and, on the contrary, more com- 
 mon in the parts which form last. 
 
 619. The bones are sometimes consecutively altered so as 
 to be increased or diminished in size. Besides the spina ven- 
 tosa and osteosteatoma, already mentioned, and which are 
 merely a dilatation of the bones: the exostoses, whether ex- 
 ternal or internal, which are only the periostosis and the spina 
 ventosa ossified; the bones are also sometimes the seat of a 
 hypertrophy. The bone is then tumefied, and there is an in- 
 terstitial deposition which keeps up or increases their original 
 density. In all cases there is an augmentation of weight. At 
 
 1793. c. F^Clossius, uber die Krankheiten der Knocken. Tubingen, 1798. 
 J. Howship, in Med. Chir. Transac. vol. viii. and x. 
 
 * Van Doeveren, Observ. Osteol. varios naturae, lusts in ossibus. hum. corp. 
 exhibent; in Obs. Acad. Specim. Lugd. Bat. 1765. Sandifort, de ossibus 
 diverso modo a solitd conformatione abhtdentibus, in Observ. Anat. Pathol. , 
 Lib. iii. and iv. Lugd. Bat. 1777-81. Rosenmuller, de ostium varietatibus. 
 Lips. 1804. 
 
394 GENERAL ANATOMY. 
 
 other times the swelling results simply from the rarefaction of 
 the compact substance. The bone, which is less dense, and 
 more voluminous, has not then sensibly increased in weight. 
 I have in my possession a very fine specimen of this kind of 
 alteration, symmetrically occupying the two parietal promi- 
 nences in a skiill of a young subject: the bone, which is greatly 
 rarefied, is extremely vascular. These two kinds of tumefac- 
 tion, when they affect the long bones, sometimes determine 
 the contraction or disappearance of the medullary canal. This 
 case has been described under the name of enostosis.* I pre- 
 sented to the Faculty of Medicine a skeleton in which almost 
 all the bones present this alteration. 
 
 620. Atrophy of the bones gives rise .prematurely to 
 changes similar to their diminution in old age. 
 
 In the Museum of the Faculty of Paris, there are long bones 
 of a young man, in which the walls of the medullary canal 
 are as thin as paper. This canal has been enlarged by internal 
 absorption, while no formation has taken place at the exterior. 
 Phthisis, when very slow, sometimes produces this alteration 
 in the bones. It is also produced by long inaction. 
 
 621. Inflammation of the bones is very imperfectly known. 
 
 The term caries is one of the vaguest words in pathology. 
 The obscurity of the thing has been increased by comparing 
 caries to ulcers. What is most generally considered as ca- 
 ries, is a softening of the spongy substance of the bone, such 
 that it can be cut with a bistoury without injuring its edge. 
 This softening appears to be the effect of an inflammation, 
 which generally terminates by suppuration, and also sometimes 
 by necrosis. 
 
 Rachitis is another kind of softening which appears to de- 
 pend upon the diminution of the earthy substance during the 
 period of growth, whence results the bending of the bones 
 under the weight of the body, and under the action of the 
 muscles. In fact, if the bones of rachitic persons be examined 
 at the period when they are soft,t it is found that the long 
 
 * Lobstein, rapport sur les travaux executes a famphlth. d'anat. de Stras- 
 bourg, 1805. 
 
 Stanley, in Med, Chir. Trans, vol. vii. Lond, 1816. 
 
OP THE ARTICULATIONS. 395 
 
 bones have become spongy in their whole thickness, and that 
 their tissue, which has become soft and red, may easily be cut 
 with the scalpel. On the other hand, when the disease is ter- 
 minated, and the bones have resumed their hardness and-in- 
 flexibility, the compact substance is found much thicker on 
 the concave side of the curvature than on the opposite side; 
 and when the bone is bent at an angle, the place at which the 
 flexure exists is entirely compact, and the medullary canal is 
 obliterated in it. 
 
 In the adult state, the softening depending upon the same 
 cause, may proceed to the same extent, and even farther: the 
 bones may become soft and pliant (Osteomalacia, seu Mala- 
 cost eon}; they may even acquire all the softness and flexibili- 
 ty of flesh (Osteosarcosis}. At this extreme degree of softness, 
 of which the woman Supiot presented an example so gene- 
 rally known, and in which the bones bend like soft wax, desic- 
 cation diminishes their weight and changes their form; de- 
 coction dissolves them; and their chemical composition is 
 changed* to such a degree that they do not contain more than 
 a few hundredth parts of earthy substance. 
 
 Lastly, it may happen, with, or without the preceding 
 changes, that the animal substance of the bones loses its na- 
 tural tenacity, and these organs, having become brittle, break 
 under the slightest effort. 
 
 622. Morbid accidental productions are also sometimes met 
 with in the bony tissue; tubercles, scirrhus, and the encepha- 
 loid production are not uncommon in them. 
 
 SECTION II. 
 
 OP THE ARTICULATIONS. 
 
 623. The Articulation, Jlrticulas, 'Ap0pa is the joining of 
 the bones. The term comprehends the manner in which they 
 
 * Bostock, in Med. Chir. Trans, vol. iv. Lond. 1813. J. Davy, in Monro's 
 Outlines of Anatomy. 
 
396 GENERAL ANATOMY. 
 
 meet, and are fitted to each other, and that in which they are 
 mutually connected. 
 
 The long bones meet and are joined to each other by their 
 extremities; the broad bones commonly by their edges; the 
 short bones, by various points of their surface. The articular 
 parts of the bones are most commonly prominences and de- 
 pressions of different forms, and which are adapted to each 
 other. 
 
 The means of union are cartilages, cartilaginiform ligaments, 
 and fibrous ligaments. They are placed, either between sur- 
 faces which they connect, and thus render continuous, or 
 around surfaces which remain in contact. 
 
 Articulations have for their common use, to connect the 
 bones, and thus form them into a united whole, the skeleton. 
 
 Of the articulations some are moveable and others not so in 
 a sensible degree; none of them, strictly speaking, however, 
 is incapable of motion. 
 
 According to the form of the articular parts, the mode of 
 union of these parts, and their solidity and mobility variously 
 combined, the articulations are divided into three genera, and 
 into several species and varieties, which have been uselessly 
 multiplied; the synarthrosis, or continuous and immoveable 
 articulation; the diarthrosis, or contiguous and moveable arti- 
 culation; and the amphiarthrosis, or mixed articulation, which 
 is continuous like the first, and moveable like the second. 
 
 Each articulation has a proper name, composed of the names 
 of the bones which are united in it. 
 
 624. Synarthrosis,* or the immoveable articulation, re- 
 sults from the union of all the bones of the skull and face, 
 excepting the lower jaw, by edges more or less thick, and 
 furnished with inequalities which fit into each other, often 
 dovetailed, and always invested with a synarthrodial cartilage 
 intimately united to the two articulated parts. The perioste- 
 
 * Duveniey. Lettre contenant plusieurs nouvelles observations sur Fosteok- 
 gie. Paris, 1689. F. G. Hunauld. Rcch. JLnat. sur ks os du crane de 
 Fhomme. Acacl. des Sc. 1730. E. G. Bose. Program, de suturar. cranii 
 liumnni fabricat. et usu. Lips. 1763. Gibson, on the use of sutures m the 
 skulls of animals, in Mem. of the Soc. of Manchester, 2d series, vol. i. 1805. 
 
OF THE ARTICULATIONS. 397 
 
 urn, in passing from the one to the other bone over the inter- 
 vening cartilage, also unites these three par.ts, to which it inti- 
 mately adheres. This kind of articulation, which is very 
 solid, has no sensible motion. It favours the growth of the 
 broad bones by their edges. It is often obliterated in old age. 
 Its disunion requires efforts of the same kind and violence as 
 those which fracture the bones. 
 
 This kind of articulation, which has received the generic 
 name of suture, presents several varieties. 
 
 625. The true suture is that in which the edges of the ar- 
 ticulated bones present numerous and extensive eminences 
 and depressions, which receive each other. Of this kind are 
 the inter-parietal, occipito-parietal, and fronto-parietal articu- 
 lations. This suture itself presents some differences. Thus, in 
 the first, they are long tooth-like prolongations; in the second, 
 they have the form of rounded tails; in the third, they resem- 
 ble the teeth of a saw. These three varieties have received 
 the names of dentate suture, sutura dentata, serrated suture, 
 sutura serrata, and margined suture, sutura limbosa. 
 
 The harmonic articulation, is that in which the edges of the 
 bone, which are more or less thick, present rugosities which 
 are fitted to each other; the suture by which the nasal bones 
 are joined to each other, is of this kind. 
 
 The squamous articulation is that in which the edges of the 
 bones are sloped like a chisel, and fitted to each other like 
 the edges'of a bivalve shell. This disposition, which is very 
 decidedly marked in the junction of the parietal and temporal 
 bones, occurs combined with the suture or harmonic articula- 
 tion in many other articulations of the skull and face. In 
 many articulations, it is double and reciprocal, so that at one 
 part, a bone overlaps the other, which in another part overlaps 
 the first in its turn. Of this kind are the spheno-frontal su- 
 tures. This mortising is one of the most powerful means of 
 ensuring the solidity of the synarthrodial articulations. 
 
 Schinclylesis is a synarthrosis which results from the recep- 
 tion of the crest or ridge of a bone into the groove of another. 
 Of this kind are the articulations of the sphenoid and ethmoid 
 
398 GENERAL ANATOMY. 
 
 bones with the vomer, the lachrymal bone with the nasal pro- 
 cess of the maxillar bone, &c. 
 
 Lastly, Gomphosis is a species of synarthrodial articulation, 
 entirely different from the suture, which results from the re- 
 ception of the roots of the teeth into the alveoli. 
 
 626. Jlmphiarthrosis,* or mixed articulation, partakes of 
 the nature of synarthrosis in having the articular surfaces 
 united by means of an intermediate substance, and of that of 
 diarthrosis in having a considerable degree of mobility. This 
 kind of articulation is confined to the body of the vertebrae, 
 the pubis and the upper parts of the sternum. 
 
 The articular parts of the bones, are here flat and broad sur- 
 faces. The means of union are intermediate cartilaginiform 
 ligaments, adhering very firmly to the two surfaces, and acces- 
 sary ligaments placed at the exterior of the articulation. This 
 kind of articulation, which is often called symphysis, pos- 
 sesses a great degree of solidity, which is owing to the tenacity 
 of the ligament. Its mobility is owing to the flexibility and 
 elasticity of the same substance. The motion consists of the 
 flexion or torsion of the ligament. This articulation, which is 
 very loose and mobile in childhood, becomes more and more 
 firm in old age, at which period it sometimes ossifies. Some- 
 times the ossification is external to it, and only surrounds it 
 more or less completely, as is especially observed at the fore 
 part of the body of the vertebrae. It may be accidentally too 
 loose or too close. It is not susceptible of a true luxation, but 
 rather of a displacement, a drawing asunder, which 'always 
 supposes the laceration or destruction of the intervening carti- 
 laginous ligament. 
 
 After certain unconsolidated fractures, there are sometimes 
 produced articulations of this kind; that is to say, the frag- 
 ments are united by the intervention of a flexible and tena- 
 cious substance, which permits them to move upon each other. 
 This mode of accidental articulations occurs after fractures of 
 the patella, the neck of the femur, the olecranon, and also 
 sometimes after those of the body of the long bones. Amphi- 
 
 * A. Beclard. Dictionnaire de Medicine, vol. ii. 
 
OP THE ARTICULATIONS. 399 
 
 arthroses also sometimes form in the place of some diarthro- 
 ses, of which the synovial membrane has contracted flexible 
 adhesions. 
 
 627. Diarthrosis is a kind of articulation in which the 
 articular surfaces of the bones are in contact, and move upon 
 each other. 
 
 This kind of articulation exists among all the bones of the 
 limbs, whether between each other, or between them and the 
 trunk, between the lower jaw and the skull, between the skull 
 and vertebral column, between the articular processes of the 
 vertebras, between the ribs and vertebrae, and between the 
 costal cartilages and the sternum. 
 
 628. The articular parts of the bones, in this kind of arti- 
 culation, are broad surfaces, whose configuration is reciprocal. 
 These surfaces are in general, the one convex, the other con- 
 cave. The convex surfaces, or articular eminences, are some- 
 times rounded like a large segment of a sphere, in which case 
 they are called heads. Others are rounded, but elongated in 
 one direction, and contracted in another: these have been 
 named condyles. The heads and condyles are sometimes sup- 
 ported by a narrow part, which is called the neck. The arti- 
 cular depressions, or concave surfaces, bear the name of 
 cotyloid cavities, when they have the form of a segment of a 
 sphere and are deep; and that of glenoid cavities, when they 
 are more superficial. Sometimes two condyles are brought 
 near each other laterally, and leave between them a neck 
 which enters into the articulation like themselves. This kind 
 of surface is named a pulley, trochlea: Lastly, many articular 
 surfaces, which are nearly flat, presenting little convexity or 
 concavity in their configuration, have received no particular 
 name, but are designated, according to their extent, under the 
 generic names of articular surfaces or facettes. 
 
 All these surfaces are covered with diarthrodial cartilages 
 (554). These cartilages are themselves covered by synovial 
 membranes (210), and moistened with synovia (216). There 
 are, moreover, between certain of these surfaces, menisci or 
 chondroid inter-articular cartilaginous ligaments (531.) 
 
 629. The means of union are fibrous ligaments, (512.) 
 
 52 
 
400 GENERAL ANATOMY. 
 
 The muscles which surround the articulations, although they 
 do not enter essentially into their composition, contribute 
 powerfully to their solidity. 
 
 630. Firmness and mobility are variously combined in the 
 diarthrodial articulations. 
 
 These articulations possess very diversified motions, as 
 sliding, rotation, angular opposition and circumduction. The 
 sliding motion exists in all the diarthrodial articulations. The 
 other motions, on the contrary, occur only in a cerain number 
 of them. Rotation is peculiar to certain articulations. Some- 
 times it is exercised upon a single pivot, as around the odon- 
 toid process of the second vertebra. Sometimes there are 4;wo, 
 as in the double articulation of the bones of the fore-arm with 
 each other. Sometimes it is round an ideal axis that a bone 
 turns, as is exemplified in the femur. The motion of opposi- 
 tion, or angular motion, is that in which the bones form more 
 or less open angles with each other, according to the degree 
 of motion. It is distinguished into opposition limited to two 
 motions of flexion and extension, as at the elbow, the knee, 
 &c.; and into vague opposition, which may take place in four 
 principal directions, and in all the intermediate directions, of 
 which examples are offered by the arm, the thigh, the thumb, 
 &c. Circumduction, which exists in all the articulations pos- 
 sessing vague opposition, is a motion by which the bone which 
 moves describes a cone whose summit corresponds to the 
 central extremity of the bone, and the base to its opposite 
 extremity. 
 
 The firmness of these articulations, like that of the others, 
 is in the inverse ratio of their mobility. 
 
 631. Several kinds of diarthrosis are distinguished, de- 
 pending upon the configuration of the surfaces, the means of 
 union; and the motions of these articulations. 
 
 The close and planiform diarthrosis, articulus adstrictus, 
 the amphiarthrosis of some, the motus obscurusof Columbus, 
 is that in which the surfaces are superficial, the ligaments 
 strong and tight, the motions obscure and confined to sliding, 
 but capable of being performed in several directions. Of this 
 kind are the articulations of the articular processes of the ver- 
 
OF THE ARTICULATIONS. 401 
 
 tebrse, and those of the bones of the carpus and tarsus, whether 
 with each other or with the metatarsus and metacarpus. 
 
 JLrthrodia differs from the preceding articulation, in this 
 respect, that the surfaces are less flat, the ligaments less tight, 
 and the motions freer and more numerous. Of this kind is the 
 temporo-maxillary articulation. 
 
 Enarthrosis consists in the reception of a head into a cavity. 
 In this species the ligament is capsular, and the motions greatly 
 diversified. The articulation of the femur with the coxal bone 
 affords an example of it. 
 
 These three first kinds of diarthrosis are orbicular or vague. 
 Their motions, which are more or less free, may take place in 
 all, or in many directions. The following species, on the con- 
 trary, are called alternate, because the motions are performed 
 in them only in two opposite directions. 
 
 The rotatory diarthrosis, commissura trochoides of Fallo- 
 pius, is that which allows only motions of rotation; of which 
 kind are the articulation of the atlas with the second vertebra, 
 and that of the radius with the ulna. It is also called lateral 
 ginglymus. 
 
 Ginglymus^ properly so called, or the hinge joint, also 
 called angular ginglymus, is the articulation in which there 
 are only two opposite motions, of which kind is the elbow 
 joint. In this species of diarthrosis, one of the bones com- 
 monly presents a pulley, and the other a corresponding sur- 
 face. There are generally two lateral ligaments. If the mo- 
 tion of extension is not to go beyond the line of direction of 
 the bones, these ligaments, in order to limit the motion, are 
 placed nearer the plane of flexion than the opposite plane. 
 
 632. Accidental diarthrodial articulations are produced 
 under two different circumstances, after fractures of which the 
 pieces have not united, and after luxations which have not been 
 reduced. Both are very complex productions. The first kind 
 may be called supernumerary, the other supplementary articu- 
 lations. 
 
 * I. F. Isenflamm and Schmidt. De Ginglymo. -Erlangx, 1785. 
 
-402 GENERAL ANATOMY. 
 
 633. The supernumerary articulations* have long been 
 known. They occur after fractures in which the fragments 
 have not been brought together, and those of which the frag- 
 ments have been frequently moved on each other. Sometimes 
 also the defect of union depends upon a constitutional affection. 
 The ends of the bones, which have a different configuration, 
 and have become compact and closed as after amputation, are 
 covered with a thin layer of imperfect or fibrous cartilage. 
 They are covered and enveloped by a synovial membrane, 
 surrounded by a fibrous capsule, generally incomplete and 
 with irregular ligamentous cords. This kind of articulation 
 has been observed, with a great number of variations, in al- 
 most all the long bones of the limbs, and several times in the 
 lower jaw and ribs. 
 
 634. The supplementary articulations have also been often 
 observed. They follow unreduced luxations, and especially 
 those of the femur and humerus. Foville and Pinel Grand- 
 champ presented me with an anatomical preparation which re- 
 presents an articulation of this kind that had been formed after 
 an unreduced luxation of the bones of the fore-arm behind the 
 humerus. 
 
 In the articulations of which we here speak, there occurs 
 a depression in the point against which the head of the 
 luxated bone rests. The circumference of this point is 
 raised by an accidental ossification. Sometimes even there 
 also occurs a circular fibro-cartilaginous rim in it. This newly 
 formed cavity is covered with an imperfect or fibrous cartilage. 
 The head of the luxated bone is commonly flattened. The in- 
 terior of the articulation is lined by a very distinct synovial 
 membrane and moistened by synovia. There is a fibrous 
 capsule, formed by the remains of the old capsule, adhering 
 to the luxated bone, by the surrounding cellular tissue, and by 
 a new production. The old cavity contracts and becomes su- 
 perficial, and the cartilage diminishes, or even entirely disap- 
 
 * J. Salzmann. De JLrthul. Analogis, quce fracturls Ossium superveniunt. 
 Argentor, 1718. Langenbech, Uber die Slldung wider naturlicher Geknkc 
 nach Knochcnbruchen, in der Neuen Biblfur die Chirurg. Getting 1 . 1815. 
 
OF THE ARTICULATIONS. 403 
 
 pears. If it is in the haunch, the cotyloid cavity diminishes, 
 and from being hemispherical becomes triangular; a fact to be 
 added to those which show that the form of organs depends, 
 partly at least, upon their reciprocal action. It would appear 
 that these changes were in part known so early as the time of 
 Hippocrates. 
 
 635. M. Chaussier* has produced, in dogs, the formation 
 of accidental articulations intermediate between the two kinds 
 above described. Having by an incision made the head of the 
 femur to come out of the cotyloid cavity, and having sawn it 
 below the trochanter, he brought the flesh together, and left 
 the animals to the care of nature. On examining the parts at 
 periods more or less remote, he found that the muscles had 
 drawn the extremity of the femur near a part of the ischium; 
 that the truncated bony extremity was rounded, and invested 
 with a cartilaginiform substance; that the point of the ischium 
 against which it rested had also assumed a cartilaginous ap- 
 pearance, and sometimes presented an articular fossette of 
 greater or less depth; lastly, that the cellular tissue formed 
 around this new articulation a kind of membranous capsule, 
 in which was contained a serous fluid in greater or less quan- 
 tity. 
 
 636. The diarthrodial articulations may be altered in their 
 solidity and in their mobility; they may be too loose or too 
 tight, and they may also be luxated or anchylosed. 
 
 637. Luxation is the more or less complete cessation of 
 the natural connexion between the contiguous surfaces of 
 bones. When it takes place, the ligaments are violently 
 stretched, drawn out, or even ruptured. The other articular 
 and surrounding parts are more or less affected by these lesions. 
 Motion is then very difficult. The most mobile articulations 
 are the most susceptible of it. Thus the arthrodiae and enar- 
 throses are those which present the greatest number of exam- 
 ples of it, and the close diarthroses those which present the 
 fewest. Of the articulations of the same species, those which 
 are the least close, those whose articular surfaces have the 
 
 * Bulletin des Sciences par la Soc. Philom. Paris, an. viii, 
 
404 GENERAL ANATOMY. 
 
 smallest extent, and those which take place between the longest 
 bones, are those which are most frequently luxated. Thus, 
 the shoulder-joint furnishes of itself more examples of luxa- 
 tions than all the others together. 
 
 638. Anchylosis,* or the uniting of the diarthrodial articu- 
 lations, consists, when it is complete, of an intimate union, a 
 real continuity between bones which were previously in con- 
 tact. The spongy substance communicates from the one bone 
 to the other. The compact plates, the diarthrodial cartilages, 
 the synovial membrane and the synovia, which separated the 
 spongy part of the two bones, have disappeared. Immobility 
 continued for a great length of time, but especially a certain 
 degree of inflammation, whether originally in the synovial 
 membrane, or at first in the ligaments and the other surround- 
 ing parts, induce these changes. Sometimes they commence 
 by an agglutination of the synovial membrane, and the forma- 
 tion between its surfaces of cellular tissue or fibrous bridles 
 which may become ossified at a later period. Sometimes the 
 articulation being laid open by a wound or the effect of an 
 abscess, it is by suppurative granulations that the agglutination 
 is established. In both cases, the diarthrodial cartilages are 
 gradually absorbed before the osseous union takes place. All 
 the diarthroses are susceptible of anchylosis, but the ginglymi 
 more than the others. 
 
 Anchylosis sometimes affects several articulations. All the 
 diarthroses and amphiarthroses have even been seen to be suc- 
 cessively affected by it, and the skeleton has thus become a 
 single inflexible mass. M. Percy has deposited in the Mu- 
 seum of the Faculty of Paris a skeleton which presents this 
 general anchylosis of all the articulations. 
 
 639. At other times, the causes of alteration of which we 
 speak determine the superficial necrosis or wearing out of the 
 articular surfaces. It is in cases of this kind that excision of 
 the articular extremities of the bones has been practised.! At 
 
 J. Th. Van de Wympersse. De Ancyksi, &e. Lugd. Bat. 1783. Idem. 
 De Jlncybseos PathoL et Curat. Lug-d. Bat. 1783. J. Cloquet, in Diction- 
 naire de Mcdecine, vol. ii. 
 
 f H. Park. Account of a New Met/tod of Treating Diseases of the Knee 
 
OP THE SKELETON. 405 
 
 other times, the adhesion of the articulation remains cellular 
 or fibrous, with a little mobility. Sometimes the destroyed 
 cartilage is reproduced. At other times it is replaced by the 
 transformation of the subjacent bony plate into ivory or ena- 
 mel. In cases of this kind spontaneous luxation of the bones 
 sometimes occurs. 
 
 1 have seen a singular displacement of the hip-joint, depend- 
 ing no doubt upon chronic inflammation. In this case the 
 upper part of the articular cavity seems to have yielded to the 
 pressure of the head of the femur, after having been softened. 
 The cavity, which has become oval, is greatly elongated and 
 hollowed out at its upper part, where it lodges the head of the 
 femur, while the lower part of the same cavity which lodged 
 it before is contracted and superficial. I have observed this 
 change sometimes on one side only, and sometimes sym- 
 metrically produced on both sides at once. 
 
 640. All the diseases of the diarthrodial articulations be- 
 long to each or to several of the parts of which they are formed, 
 to their serous membranes, their cartilages, their ligaments, 
 and to the articular parts of the bones. 
 
 SECTION III. 
 
 OP THE SKELETON. 
 
 641. The skeleton is the aggregate of all the bones con- 
 nected with each other by the articulations. It is called na- 
 tural, when the bones are kept together by their proper liga- 
 ments, and artificial, when the bones are united by substances 
 foreign to the organization. 
 
 It constitutes a symmetrical whole,* which has the form and 
 
 and Elbow. London, 1783. Moreau, De la Resection des Os. &c. Paris, 
 1816. J. Jeffray. Cases of the Excision of Carious Joints, by H. Park and 
 P. F. Moreau, with observations. Glasgow, 1806. Wachter. Diss. de JLr- 
 ticul. Extirp. Groningue, 1810. Roux, De la Resection, &c. Paris, 1812. 
 * Loschge. De Scekto Hum. Symmetrico, &c. Erlang. 1795. 
 
406 GENERAL ANATOMY. 
 
 dimensions of the entire body, which dimensions it in a great 
 measure determines. 
 
 It is 'divided into the trunk and limbs. The trunk, the cen- 
 tral and principal part, and which is formed in the median 
 line by the vertebral column, presents two great cavities. The 
 one, which is superior and posterior, and is formed by the 
 skull and vertebral canal, lodges the nervous centre; the other, 
 which is anterior and inferior, and is formed by the thorax, 
 lodges the central organs of the nutritive functions. Other 
 cavities (those of the face), receive the organs of sense, &c. 
 The appendages or limbs which are furnished with numerous 
 articulations, possessed of great mobility, are especially sub- 
 servient to motion. 
 
 642. The uses of the skeleton are to form the solid and 
 flexible axis of the body, furnish protecting envelopes to the 
 nervous and vascular centres, and to the organs of sense, afford 
 points of attachment to the muscles, and determine by its ar- 
 ticulations the extent and direction of the motions. 
 
 The skeleton performs part of its functions through the 
 hardness and rigidity of the bones, and the solidity of the ar- 
 ticulations. The rest it performs through the mobility of the 
 articulations. 
 
 643. In their motions, the bones articulated by diarthrosis 
 act in the manner of levers. 
 
 The greater part are levers of the third kind, or that in which 
 the power is interposed between the fulcrum and weight. The 
 centre of motion or fulcrum is in the articular extremity of the 
 bone, the resistance or weight at the other extremity, and the 
 muscular power is applied in an intermediate point, which is 
 commonly very near the fulcrum. Some of them are levers 
 of the second kind, or that in which the weight is intermediate 
 between the fulcrum and power. Some also are levers of the 
 first kind, in which the fulcrum is interposed between the 
 weight and the power. 
 
 644. As the bones are not all formed at the same time, 
 and do not all grow in the same proportion, the form and pro- 
 
OF THE SKELETON. 407 
 
 portions of the skeleton, and not merely its dimensions under- 
 go great changes through age.* 
 
 The proportion of the head to the rest of the trunk and to 
 the limbs is so much the greater, the younger the subject is, 
 only within the twentieth year. At the second month after 
 conception, it forms half the height of the body, nearly the 
 fourth at birth, the fifth when three years old, and the eighth 
 only when the growth is complete. The face in like manner 
 is so much the smaller, compared with the skull; the pelvis, 
 compared with the thorax, the limbs compared with the 
 trunk, &c. the younger the subject is. Many other differences 
 of the same kind will be pointed out in the particular anatomy 
 of the bones. 
 
 645. The skeleton presents pretty distinct differences in 
 the two sexes, t In general the skeleton of the female is smaller 
 and more delicate than that of the male; the thorax is shorter, 
 and altogether smaller; it is also more mobile; the pelvis 
 broader; the lumbar region more elongated, &c. The diar- 
 throdial articulations are more mobile, the amphiarthrosis more 
 flexible, &c. All the regions of the body, and almost all the 
 bones, present some particular differences. 
 
 646. The human races also present differences in their 
 skeleton, the principal of which have reference to the dimen- 
 sions and form of the skull, and its proportion to the face.J 
 There are also some differences in the proportions of the limbs. 
 In the negro race, the upper limbs are longer in proportion to 
 the trunk; the fore-arm and leg are longer proportionally to 
 the arm and thigh. 
 
 647. Lastly, individual varieties are observed in the 
 
 * Boehmer. op. cit. Cheselden, op. cit. Eyson, op. cit. Sue, Sur les 
 Proportions du squektte de rhomrtle, examint depuis Page k plus tendre, 
 jusqu'd celui de vingt-cinq, Soixante arts et au-dela,- in Mem. Pres. vol. ii. 
 F. G. Danz, Grundriss der Zergleiderangskunde des ungebornen kindes, 
 Francoff, 1792. Senff, op. cit. 
 
 f See J. F. Ackermann, De Discrimine Sexus prefer genitalla. Mogunt, 
 1788. Compare also Albinus, Tabula sceleti hominis, and Soemmering-, 
 Tabula scekti foeminei, Francof. ad Moenum, 1796. 
 
 $ Blumenbach, Decades Craniorum, i.-vi. Soemmering, De Ossilus. 
 53 
 
408 GENERAL ANATOMY. 
 
 skeleton, both with respect to dimensions, and with reference 
 to proportion, configuration, want of symmetry, &c. 
 
 The stature of the body, which is determined by the dimen- 
 sions of the skeleton, is about five feet four inches in the adult 
 man, and about five feet in the female; but this length, which 
 varies somewhat in the different races, and even in still more 
 restricted varieties of the human species, presents considerable 
 differences in the individuals of the same race or nation. These 
 differences, like those of the other species of animals, are con- 
 fined within certain limits. Thus, dwarfs are seldom of less 
 than half the mean stature, and giants are very seldom more 
 than a half higher than the ordinary stature. What has been 
 said of giants from seventeen to twenty -five feet high, must be 
 referred to bones of animals mistaken for human bones. 
 
 The proportions which the limbs bear to the trunk and its 
 different parts, or those of the limbs to each other, also present 
 numerous individual varieties, determined by those of the 
 bones. This is also the case with the general configuration 
 and symmetry of the body, their variations being almost all 
 determined by those of the skeleton. 
 
 648. The osseous system terminates the systems which 
 have for their basis the mucous substance or the cellular tissue 
 variously modified. The tissues which remain to be described 
 are, on the contrary, essentially formed of globules united by 
 the same substance. 
 
OP THE MUSCULAR SYSTEM. 409 
 
 CHAPTER IX. 
 
 OP THE MUSCULAR SYSTEM. 
 
 649. The muscular system,* systema musculare, com* 
 prebends all the organs formed of long, parallel, soft, irritable 
 and contractile fibres, which are of a reddish colour in warm 
 blooded animals, and are called muscular ; these organs 
 produce all the great motions which take place in living 
 bodies. 
 
 The name of muscle, mus, pvj, from ^tr, to contract, indi- 
 cates this property; the muscles are in fact the organs of mo- 
 tion. 
 
 650. It may appear astonishing, but it is nevertheless 
 true, that the first anatomists, Hippocrates and Aristotle, were 
 unacquainted with the muscles and ignorant of their uses. 
 The anatomists of the Alexandrian school were acquainted 
 with these organs, and have mentioned some of them. Galen 
 had a pretty accurate knowledge of them; he represents the 
 muscle as formed by the nerve and by the ligament divided 
 into fibrils, forming a tissue which he calls stcebe, the inter- 
 stices of which are filled with flesh; he supposes the muscles 
 to be endowed with a tonic faculty, or contractile force, and 
 in a state of elastic tension, inherent in their tissue and inde- 
 pendent of life; movement would depend, in that case, on the 
 voluntary relaxation of the antagonist muscles. 
 
 * W. G. Muys, Investigatio fabricae, quse in partibus musculos componenti- 
 bus extat. Diss. i. ; de carnis musculosse fibrarurfi carntarum strudura, Sec. 
 Lug-d. Bat. 1741, 4to, clij. et 432 p. Prochaska, de carne musculari tracta- 
 tus anat. physioL Vienna, 1771; et in op. min, pars. i. ; Viennx, 1820. F. 
 Ribes, flictionn. des Sc. Med. articles muscle,, musculaire, et myologie. 
 
410 GENERAL ANATOMY. 
 
 In his time a voluntary contraction more prompt and more 
 extensive than this contraction by elasticity was also admitted. 
 At the epoch of the revival of the sciences, myology was 
 still in the very imperfect state in which it had been left by 
 Galen; it is indebted to James Dubois (Sylvius] for consider- 
 able advancement: he named most of the muscles, which had 
 previously taken place only with respect to a very small num- 
 ber of them. Vesalius, and the other anatomists of the Italian 
 school, Eustachi especially, have perfected the knowledge of 
 the muscles, and have figured them. The intimate texture of 
 the muscles, their contractile action, the nervous influence of 
 this action, and the movements which result therefrom, have 
 been sedulously studied during the course of the two last cen- 
 turies, and are still the subject of important labours.* 
 
 651. In the more simple animals, the muscular fibre is not 
 distinctly perceived: in them movements are produced by the 
 cellular tissue. In the first of the series where the muscular 
 fibre appears, it only moves the tegumentary membranes to 
 which it is annexed or of which it forms a part. In all those 
 which possess a heart, this fibre is the principal element of 
 this organ. Lastly, in the vertebrate animals, a few muscles 
 only are attached to the mucous membrane, to the skin, and to 
 the senses, their dependencies; a great number, on the contra- 
 ry, are attached to the skeleton, in order to move it. 
 
 652. In man there are two classes of muscles: the first, 
 interior, membraniform and hollow, appertaining to the mu- 
 cous membrane and the heart, contracting involuntarily, and 
 subservient to the functions of nutrition and of generation, in 
 a word, to the vegetative functions; the second, exterior, 
 more or less thick and full, belonging to the skin, to the senses, 
 to the skeleton, and to the larynx, contracting voluntarily and 
 subservient to the animal functions. Both classes present 
 characters common to each other, which it is necessary to 
 consider generally. 
 
 Messrs. Prevost and Dumas are making observations on the intimate 
 texture of muscles and on muscular action. They have had the goodness to 
 communicate to me the first results, as yet unpublished. 
 
OP THE MUSCULAR SYSTEM IN*GENERAL. 311 
 
 SECTION I. 
 
 OP THE MUSCULAR SYSTEM IN GENERAL. 
 
 653. The muscular system forms of itself a great portion 
 of the weight and volume of the body. 
 
 654. However diversified may be their form and situa- 
 tion, the greater part of the muscles are divided into bundles, 
 and are all formed of primitive or simple fibres, collected into 
 fasciculi. 
 
 The authors who have treated on this point of minute ana- 
 tomy, have in general presented it in a manner but little in- 
 telligible: some simply observe, that the flesh is composed 
 of fibres; others, of fleshy stria?; others again, of fibres and 
 fibrils; and lastly, others state that it is composed of fibres, 
 themselves composed of villi. Muys has made a ternary divi- 
 sion. He divides the muscular flesh into fibres, fibrils and 
 threads. He subdivides the fibres into three orders: large, 
 mean and small; the large being composed of the mean, and 
 the latter of the small fibres; the same with respect to the 
 fibrils, the smallest of which compose the mean, and these 
 compose the largest, the latter composing the smallest of the 
 fibres; the same again as to the threads, of which the most 
 minute of the fibrils are composed; according to this doc- 
 trine, the muscles would be the result of nine successive de- 
 grees of composition. 
 
 Others, rejecting this analysis as altogether imaginary, ad- 
 mit an infinite divisibility. But it is well established, on the 
 contrary, that, with respect to the muscles, as with all organic 
 substance, we arrive by microscopic inspection, at a degree of 
 division finite and well determined. 
 
 655. The muscular bundles, lacerti, are not equally dis- 
 tinct, numerous and voluminous in all the muscles; the bundles 
 composing some of them, are so distinct and large that they 
 may be considered as so many particular muscles: such are 
 the portions of the biceps, triceps, the bundles of the deltoid, 
 of the masseter, of the glutaeus magnus, &c.; such are also 
 
412 ^ENERAL ANATOMY. 
 
 the fleshy columns of the ventricles of the heart, the longitu- 
 dinal bands of the colon, &c. There are, on the other hand, 
 many of the muscles which scarcely equal a small portion of 
 a bundle of which the preceding are composed, and which are 
 not formed of distinct bundles. 
 
 The muscular bundles are themselves formed of bundles less 
 voluminous, and these latter of others still more minute, which 
 may be distinguished in almost all the muscles. 
 
 656. All the muscles may moreover be divided into fasci- 
 culi or fibres visible to the eye, fasciculse sen Jibrse secunda- 
 rise. These fasciculi, the ultimate degree of division percep- 
 tible to the naked eye, have, in all the muscles, nearly the 
 same form and the same thickness. They may, according to 
 the preceding divisions, be perceived by a longitudinal dis- 
 section, but still better by a traverse section, and especially in 
 a muscle boiled or steeped in alcohol. They have a prismatic, 
 pentagon or hexagon form, and never a cylindrical one; their 
 diameter varies a little; their length, according to Prochaska, 
 is equal to the entire extent of the interval between their two 
 attachments, even in the sartorius muscle. Haller, on the 
 contrary, thought with Albinus, that the fibres or the fasciculi 
 were not so long as the muscles, and that fasciculi of fibres 
 terminated by tapering off in the intervals of other similar 
 parts; this does not appear to be the case. 
 
 657. The muscular fibres, Jibrse musculares primarise y 
 seufila carnia, visible only by the aid of the microscope, are 
 the ultimate degree of anatomical analysis of the muscles. 
 We are indebted to Hooke, R. Leuwenhoeck, Dehayde,Muys, 
 De la Torre, Prochaska, Wenzell, (Brothers,) M. Autenrieth, 
 M. Sprengel, Messrs. Ed. Home and Bauer,* and to Messrs. 
 Prevost and Dumas,t for the best observations on this subject. 
 It must be remarked, however, that the first of these observers 
 having in their researches only made use of lenses which mag- 
 nified about 150 times, were not enabled to perceive the pri- 
 
 * Croonian Lecture, in Philos. Trans, ann. 1818. 
 
 f Examcn du sang el de sm action dans les divers Phenomenes de la J r ic; 
 in Annalts de chimie et de Phys. t. xxii. 
 
OF THE MUSCULAR SYSTEM IN GENERAL. 413 
 
 mitive fibres, which require, in order to be seen, to be magni- 
 fied about 300 times; their observations therefore relate only 
 to secondary fibres. 
 
 Hooke observed that the muscles of many animals are com- 
 posed of an innumerable quantity of fine threads, the volume 
 of which he estimates at the hundredth part of a hair, and 
 compares its figure to that of a series of pearls or beads of 
 coral. Leuwenhoeck, after having perceived the muscular 
 fibres, which he calls primitive, conjectured that they were 
 again composed, founding his idea, though incorrectly, on 
 the supposition that spermatic animalcules, still nrore minute 
 than fibres, must be provided with nerves and with mus- 
 cles; he moreover delineated rough figures of them; those of 
 Dehayde, though coarse also, are more exact. Muys has 
 given descriptions of them equally long and exact, he repre- 
 sents them as most generally cylindrical, and seldom knotty. 
 De la Torre says they are reddish, which is not generally 
 true. The observations of Prochaska, which are much more 
 exact, prove that these fibres are parallel but not always 
 straight, and that in cooked flesh they are almost always flexu- 
 ous; that their form is not cylindrical, but flat and prismatic; 
 that their substance is diaphanous and appears to be solid; their 
 diameter, with little variation, appeared to him to be seven or 
 eight times less than the largest diameter of a red globule of 
 blood. This observation, however, seems to be inaccurate; 
 he considered these fibres as constituting the ultimate degree 
 of the division of the muscles, without going so far as to affirm, 
 however, that these are the elementary fibres. The micro- 
 scopic observation made by the brothers Wenzell, on a por- 
 tion of muscle previously immersed during eight days in a 
 mixture of alcohol and muriatic acid, discovered to them that 
 each fibre was composed of round and minute corpusculi. Ac- 
 cording to M. Autenrieth, the diameter of these fibres is the 
 fifth of that of the globules of the blood. M. Sprengel, on the 
 contrary, estimates the diameter of the muscular fibre at seven 
 times that of a globule of blood, (which is the three hundredth 
 part of a line) that is to say, at about the fortieth part of a line; 
 he moreover describes it as angular, striated and full. The 
 
414 GENERAL ANATOMY. 
 
 microscopic observations of M. Bauer and of M. E. Home, 
 published with very beautiful plates, represents the muscular 
 fibre as identical with the particles of blood divested of their 
 colouring matter, and the central globules of which have 
 united in filaments. Messrs. Prevost and Dumas have uni- 
 formly obtained the same result, whatever may have been the 
 animal submitted to their examination, or whatever may have 
 been the form and volume of their globules; my own observa- 
 tions accord entirely with theirs. That the observation may 
 be divested of all doubt, it ought to be made on raw and un- 
 prepared muscular flesh; in fact, coction and the action of 
 alcohol produce globules by coagulating the albumen, and we 
 may attribute their presence in the muscular fibre to these 
 causes. These globules are united by a medium, invisible be- 
 cause of its transparency and want of colour; it is a kind of 
 jelly or mucous. If muscular flesh be macerated in water 
 frequently renewed, putrefaction changing more promptly 
 the means by which the globules are united than the latter 
 themselves, and the renewing of the water inducing the pro- 
 duct of putrefaction, isolated globules are obtained similar to 
 those of the coloured particles of the blood. The fibres of all 
 the muscles have the same volume as well as form. 
 
 658. Wrinkles or flexuosities are often perceived on the 
 fasciculi of the muscles, particularly when boiled. This ap- 
 pearance was noticed by Hooke, Leuwenhoeck, Dehayde and 
 Haller, was well delineated by Muys,and engaged the special 
 attention of Prochaska, who attributes it to the contraction of 
 the cellular tissue, vessels and nerves, and to their crispation 
 by coction. These apparent wrinkles or stris have also been 
 ascribed to several other imaginary causes, and have produced 
 the supposition that the fibres have an articulated, twisted or 
 spiral disposition. These wrinkles are, or at least appear to 
 be, nothing more than flexuosities or undulations; they always 
 exist in contracted muscles, whether in the living, or in the 
 dead subject, or by the action of caloric. This flexuosity is 
 produced of its own accord when the retraction of a muscle is 
 assisted, or when .produced by cutting, by bringing its attach- 
 ments towards each other, or by pushing them towards each 
 
OF THE MUSCULAR sf STEM IN GENERAL. 415 
 
 other; on the contrary, they disappear when the muscular 
 fasciculi are extended in the dead subject. They disappear 
 entirely when the cadaverous stiffness has disappeared. 
 
 659. Some physiologists, deceived by incorrect observa- 
 tions, or governed by hypothetical views, have admitted false 
 or entirely arbitrary opinions as to the intimate texture of the 
 muscular fibre:* thus a great number of physiologists and 
 mechanicians have admitted that the muscular fibre is hollow, 
 and that it consists of a series of ovoid vesicles, or of rhom- 
 boidal cavities, elongated in a state of relaxation, but widened 
 and globular when the. muscles are in a state of contraction. 
 Several have considered the muscular fibre to be hollow and 
 continuous to the nerves. Many others have considered it as 
 hollow, vascular and injectable, either as being formed solely 
 of small arteries or as consisting of very minute vessels inter- 
 vening between the small arteries and small veins. Others 
 have described these interior cavities, both vesicles and ca- 
 nals, as spongy and.cellular. . Some have admitted transversal, 
 nervous or other fibres, either intended to retain the blood in 
 the fibre, or to close its' dilated canal and to shorten it by this 
 mechanism. Others again have imagined the fibres to be a 
 spiral canal around a thread which is incapable of extension; 
 While others have supposed it to be twisted like a thread of flax 
 or hemp, c. 
 
 It may be objected to all these a-ssertions that the muscular 
 fibre, when examined with good optical instruments, appears 
 to be the result of a linear series of opaque globules, united by 
 a medium more transparent, but that nothing is found to indi- 
 cate that these globules are vesicles; that when the muscular 
 contraction takes place, wrinkles are perceived to form, 'but 
 these flexuosities are effaced as soon as the muscle is relaxed, 
 no change at all, however, occurs in the figure of the globules; 
 that in insects, in which no vessels exist, there are nevertheless 
 muscular fibres which' consequently can not be the continua- 
 tion of them; "that injection may indeed swell the muscles by 
 infiltrating between the fibres, but that it does not penetrate 
 
 * Haller, Ekmento'pJiysiolog. lib. xi, sect, i, et iii. torn. iv. 
 54 - 
 
416 GENE-RAf? ANATOMY. 
 
 them; that*the supposed transverse, twisted, 'and spiral fibres 
 &c., have never been seen, 'but only imagined, in support of 
 certain hypotheses in reference to muscular action; that in 
 short, the muscular fibre, differing essentially in' its organic 
 character, and in its vital phenomena, from the cellular and 
 nervous tissues, as well as that of the vessels, can not be as- 
 similated to these tissues. M.ascagni has revived and modified 
 one of those opinions, by considering the primitive cylinders 
 of the muscles'as formed of absorbent vessels filled with a con- 
 tractile glutinous substance in the living subject, constantly 
 renewed by the circulation. Nothing, however, demonstrates 
 this to be the case, or that the fibres are hollow; it is much 
 more probable that they are solid. *& pNfetfe . 
 
 660. The muscles are enveloped by the cellular tissue 
 which forms membranes and sheaths for them: it is- the same 
 with regard to their bundles and the subdivisions of these 
 
 O 
 
 bundles; only, in proportion as the parts enveloped are less 
 voluminous, the cellular tissue forms envelops more slender 
 and soft. The fasciculi are enveloped and united together by 
 almost imperceptible layers of this tissue; in fact, the primitive 
 fibres are united together in each fasciculus, by prolongations 
 of its envelop, which, by their tenuity and softness, entirely 
 elude observation. The cellular envelops are perceptible either 
 by separating the bundles and the fasciculi from each other, or 
 by cutting the muscle transversely. 
 
 Adipose* tissue is likewise found surrounding the muscles in 
 the intervals of their bundles, and sometimes even between 
 the fasciculi. 
 
 661. The blood-vessels of the muscles, well described by 
 Albinus and Haller, and delineated by Prochaska and Mas- 
 cagni, are very numerous, less so, however, in the mucous 
 membrane. Their abundance is proportioned to the size of 
 the muscles; nevertheless, the interior muscles are more vas-- 
 cular than the exterior, and among the former some in particu- 
 lar are very much so. The veins, as in most of the parts, 
 possess a capacity superior to that of the arteries. They. all 
 communicate with the vessels of the tegumentary membranes, 
 especially in the immediate neighbourhood of the muscles: 
 
OF THE MUSCULAR SYSTEM IN GENERAL. 417 
 
 they all, after being first divided' in. the cellular membrane, 
 and there presenting considerable anastomoses, penetrate at 
 various angles the divers bundles, and are there again sub- 
 divided in order to penetrate between the fasciculi, and more- 
 over into the intervals of the fibres, always following the cel- 
 lular envelops, and continually presenting new divisions and 
 new anastomoses. In all their course, these vessels accompany 
 the divisions of the muscles by twigs parallel to them, and 
 again cross the direction by other transverse twigs which -sur- 
 round them. Arrived at their ultimate point of division, the 
 arteries continue their course with the veins, without our be- 
 ing able to ascertain how they contribute to the texture and to 
 the nutrition of the fleshy fibres. 
 
 It is not-to.the blood-vessels of the muscles that the reddish 
 colour of these organs is owing, for the interior muscles, which 
 are very vascular, are whitish. 
 
 Lymphatic vessels are to be distinctly seen in the intervals 
 between the greater pfcrt of the muscles, and in the thickness 
 of some of them; as to the manner in which they arise, it is 
 unknown: possibly they may be the continuation -of the cellu- 
 lar tissue interme.dial to the fibres. 
 
 662. The nerves of the muscles are very voluminous; ex- 
 cepting the skin and the senses, no part is so abundantly pro- 
 vided with them. In general they are proportionate in num- 
 ber and size to the volume of the muscles; nevertheless the in- 
 terior muscles have less in general than the others, and among 
 these latter, those of the skeleton less than those'of the larynx 
 and senses. They generally accompany the bloodvessels, and 
 particularly the arteries, and are slightly attached to them by 
 the cellular tissue. In order to perceive them distinctly, the 
 muscles must be mascerated until arrived at a state of putre- 
 faction, which in effect destroys the muscles more rapidly than 
 the. nerves; they penetrate at divers points into the muscles, 
 and there are divided in the same manner as the vessels; but 
 they very soon elude the sight, without the possibility of being 
 seen by.any artificial means; so that nothing can be positively 
 affirmed as to their termination. It is conjectured with some 
 appearance of probability, that .their divisions extend as far as ' 
 
418 GENERAL ANATOMY. 
 
 the primitive fibres. It would seem that before they disappear 
 altogether, they become soft, divesting themselves'of their own 
 jenvelop, so that their medullary substance comes in imme- 
 diate contact with the muscular fibre. Munro and Smith 
 thought they had perceived that the nerves of the muscles 
 have their fibres twisted in a spiral line. 
 
 According to Messrs. Prevost and Dumas,*,the nerves of 
 the muscles are perceived in the following manner in prefer- 
 enc^e to any other: a bit 'of the muscle of beef is examined after 
 being macerated in pure water, and in a dark place; by throw- 
 ing a cone of lively light on the muscle only, we distinguish 
 the colour of the nerve to be obviously different from that of 
 the muscle, and it can be traced very far by means of a good 
 lens, and a very slender scalpel; the ramifications are then seen 
 to terminate by inserting themselves between the muscular 
 fibres, the direction of which they cut at right angles. In or- 
 der to observe this arrangement throughout the whole mass of 
 a muscle thin enough to be transparent/the rectus abdominalis 
 of the frog is laid on a thin plate of glass, it is examined by 
 illuminating it by transmission by means of a weak magnify- 
 ing glass and the light of a candle: the nerve and its twigs are 
 then perceptible, and may be distinguished from the muscula^ 
 fibres and their direction. In fact, the trunk of the nerve con^ 
 tinues its course through the thickness of the muscle parallel 
 to its length, and its branches separate from it at right angles 
 to enter between the fasciculi and the muscular fibres; and as 
 they are all formed on the same plan, because of the moderate 
 thickness of the muscle, they represent a sort of comb. If the 
 muscle be contracted, th'e last visible transverse fibrils of the 
 nerve are seen to correspond exactly with the summit of the 
 angles, or of the flexuosities of the muscle. 
 
 The nerves, though numerous and voluminous in the mus- 
 cles, escape the sight long before their divisions are by any 
 means sufficiently multiplied to admit of their being distributed 
 to all the muscular fibres. Two hypotheses have bee'n imagin- 
 ed to explain their action in all the fibres. Isenflamm and M. 
 
 * Unpublished memoir. 
 
OP THE MUSCULAR SYSTEM IN GENERAL.. 419 
 
 Carlisle suggest that the nerves, at their termination, are diffus- 
 ed in the cellular tissue of the muscles,*nd that this tissue par- 
 ticipates of the conducting property of the nerves. Reil admits 
 the nerves possess a sphere of activity extended beyond 
 termination, and which he calls nervous atmosphere; 
 these are suppositions which shall be examined hereafter. 
 
 663. The greater number of the muscles indeed, have the 
 extremities of their fibres attached to ligamentous tissue, through 
 the medium of which their*action is transmitted more or less 
 distinctly. But these ligamentous parts are much- more dif- 
 fused in the exterior than the interior muscles. 
 
 664. The colour of the muscles varies greatly: those of 
 the invertebrate animals and those of the cold blooded verte- 
 brated animals are white; those of birds, mammiferous ani- 
 mals and man are some of them reddish, of the tint generally 
 known by the name of flesh colour; the others are of a grayish 
 white: the shade varies very much in all; it varies also ac- 
 cording to different circumstances, existing before or after 
 death. The colour is removed by washing or maceration; 
 it appears moreover the lighter in proportion as the muscle, 
 the bundle or the fasciculi is minute, and on the contrary, 
 the deeper in proportion as the size of the mass is greater. 
 In thin slices, muscular substance is semi-transparent. 
 
 The consistency of the muscle greatly -varies, even in the 
 dead body, as well from the causes which have acted before or 
 after death, and will be examined when we come to speak of 
 their irritability. In general, the muscular fibre is soft, hu- 
 mid, slightly elastic, and easily torn in the cadaver. 
 
 665. Muscular flesh exposed in thin slices to the action 
 of a current of dry air, or of a stove, loses more than half of 
 its weight, becomes brown, more transparent, and very hard. 
 On the contrary, if it be put in cold water frequently renew- 
 .ed, the flesh loses its hue entirely, and assumes a straw colour- 
 ed tint; maceration moreover softens and swells it. 
 
 Alcohol, diluted acids, the solution of corrosive sublimate; 
 those of alum, common salt, and nitrate of potash, augment 
 the consistency of the muscle, slightly contract it, favour its 
 
420 GENERAL ANATOMY. 
 
 separation into fibres and change its colour in various manners. 
 Alcohol renders it paH; alum turns it brown and hardens it 
 greatly: nitrate of potash and common salt render it slightly 
 red, and having at first hardened it, afterwards soften it, espe^ 
 cially the first, while it retards its decomposition. According 
 to the observations, as yet unpublished, of Mr. Britonneau, 
 and those of Mr. Labaraque, the solution of chlorid of calcium 
 at a suitable degree of concentration, preserves the consistency, 
 the flexibility and other natural.qualities of muscular flesh and 
 the other soft parts. 
 
 666. Muscular substance treated with cold water, yields to 
 it colouring matter, somewhat differing from that of the blood, 
 some gelatin and albumen, and an extractive matter noticed 
 by Thouvenel. 
 
 ' Submitted to the action 'of boiling water, flesh furnishes a 
 greater portion of these same substances, and moreover some 
 fat. The muscle thus treated, and exhausted by the pro- 
 longed action of water, there remains only some discoloured 
 fibres, insoluble in water, 'easily separated, by desiccation be- 
 coming brittle, and having all the properties of fibrine. Mus- 
 cular substance being calcined, leaves about one twentieth of its 
 weight of saline matter. 
 
 It follows from these facts, observed by Thouvenel, Four- 
 cro) r , M. Thenard and others, that the muscles are principally 
 composed of fibrine, that they also contain -albumen, gelatin, 
 extractive, osmazome of M. Thenard, phosphates of soda, am- 
 monia and lime, and carbonate of lime. 
 
 These observations have been particularly made on ox's 
 flesh; but as the chemical properties of the muscles present 
 differences even in animals of a nature very similar, they are* 
 not perhaps exactly applicable to man. 
 
 667. During life, the muscles enjoy an active force or 
 property, commonly designated under the names of muscular, 
 irritability, muscular force, or myotility. 
 668. Muscular action* has been the subject of much labour 
 
 'See Fr. Glisson, anaJt. Jiepatis. Lend. 1654. Swammerdam, Biblia.nat.,, 
 
. OF THE MUSCULAR SYSTEM IN GENERAL. 421 
 
 and research on the part of Haller, of several physiologists 
 anteripr to him, and of a great number of his cotemporaries 
 and of his successors. 
 
 The study of the muscular action comprehends: 1st, that of 
 the phenomena of this action; 2d, that of its. conditions; 3d, 
 that of its principle or. cause, and 4th, that of its effects. 
 
 669. The phenomena of the muscular action which are 
 best known are the following: the muscle in action becomes 
 shortened, tumefied, hardened; we are uncertain whether or 
 not its volume "changes; its colour does not vary; it presents 
 wrinkles or folds on its surface; its fibres and fasciculi are 
 often in a tremulous or oscillating state depending on its alter- 
 nate contraction and relaxation: it acquires great force and 
 manifest elasticity: these are the phenomena of contraction; 
 the most remarkable of these facts indeed, is the shortening of 
 the muscle. When the action ceases, all these phenomena 
 disappear, and the muscle is then in a state of relaxation. 
 
 torn. ii. Haller, departibuscorp. ham. irriiabiKbuSf in comm. Getting, torn, 
 ii, et in nov. comm. Getting 1 , torn. iv.-&M?moires sur la nature sensible et irri- 
 table des parties du corps humain. Laus. 1756-59. Petrini, sull 'inscnsib. e 
 irritab. dissert- transp. Iloma, 1754. Fabri, sull insensitiva e irrit. opulscol. 
 raccolti.; Bonon, 1757-59. A. G. Weber, de initiis acprogr. doctr. irritnb., 
 etc, Halx, 1783. J. L. jGautier, (prses. JReil.} da Irritabil. notione, etc. 
 ftalx, 1793. Croonian-^ lectures on muscular motion, in Philos. Trans. 1738. 
 1745, 1747, 1751, 1788, 1795, 1805, 1810, 1818, &c. J. Chr. A. Claras, 
 der Krampf. Lips. 1822. Lucae, G-rundlinien einer physiol. der irrilabilitat 
 des menschlicheu organismus, in Mechel's Arcli. B. iii. G. Blane, On muscu- 
 lar motion,- Lond. 1788, et in select. Dissert., etc. Lond % 182%. : BarzeJotti, 
 Esamc di alcune moderne teorie alia causa prossima della contrazione musco- 
 lartj Sienna, 1796, et in ReiPs Jirchiv. B. vi. H. Mayo, Anal, and Physiol, 
 commentaries) No. 1. Lond. 1822. 
 
 f Dr. W. Croone, who died in 1684, left the plan of two lectures to be 
 instituted, the .one at the Colleg-e of Physicians, on the nerves and brain: 
 the other, which was to be annual, at the Royal^ Society of London, on the 
 nature and laws of muscular motion. The latter is still continued, and has 
 given rise to several excellent papers, both on the texture and action of 
 the muscles. Several of these lectures are not consigned in the Philosophi- 
 cal Transactions. 
 
422 GENERAL ANATOMY. 
 
 Are the muscles also susceptible of active elongation? Nu- 
 merous facts have been cited in favour of this opinion. Among 
 them, there are some* which prove nothing in its favour; 
 others, reported by Bichat, Autenrieth, Sprengel et Meckel, 
 leave the question still at least undecided. 
 
 It has been also admitted that there is in the muscles & fixed 
 situation, or an action in which they are neither contracted 
 nor elongated. The same may be said of this phenomenon as 
 of the preceding. , 
 
 . 670. The contraction or shortening being the fact best 
 established in the muscular action, it must be examined in de- 
 tail, as well -as its concomitant phenomena. 
 
 The muscle augmenting in thickness at the same time that 
 it is shortened, the simultaneous occurrence of these two phe- 
 nomena, has given rise to a question that has greatly occupied 
 the attention of physiologists, and which is not yet entirely 
 resolved: it is to ascertain if the volume of the muscles changes 
 at the moment of their contraction. 
 
 The experiments of Svvam|nerdam, Glisson, Goddart and 
 Erman, on the diminution of the size of the muscles during 
 their contraction, does not prove decidedly that this dimi- 
 riution takes place. The same obtains with respect to the 
 experiments and the reasonings of Amberger, Prochaska and 
 Mr. Carlisle in favour of augmentation; they leave the ques- 
 tion equally undecided. It is very probable, according to 
 the observations and experiments of Mr. G. Blane, Barzelotti, 
 Mr. Mayo and Messrs. Prevost and Dumas, thai there is no 
 change of volume, and this accords with the opinion of Soem- 
 mering, Sprengel and Meckel; the shortening and swelling of 
 the muscle mutually compensating each other. 
 
 671. The shortening manifests itself by various effects. 
 The swelling is evident to the simplest observation. The* in- 
 duration is sensible to the touch. 
 
 672. The colour of the muscles suffers no change during 
 the contraction. It has been thought that the contrary was 
 
 * V. Barthez, nouv. Um. de la science de Fhomme, tome i. 
 f Barthez, ibid. 
 
OP THE MUSCULAR SYSTEM IN GENERAL. 423 
 
 perceived on examining the heart of young animals while in 
 action; the apparent change of colour is only owing to its 
 transparency. 
 
 673. Many physiologists have ascribed the. muscular ac- 
 tion to the accumulation of blood in the muscles, either in the 
 interior itself, or the invervals of the fibres; others to causes 
 analogous, all of which suppose an- augmented activity of the 
 circulation during the muscular action. Haller has already 
 offere^ many objections to these hypotheses. There is no 
 direct proof of the afflux of blood in the muscles during their 
 action. The experiments of Barzelotti. moreover prove that 
 the contraction 'of the muscles of the frog ? excited by galvan- 
 ism, can take place after death: 1st, when the blood no longer 
 circulates in the vessels; 3d, when the blood is even congealed, 
 and 3d, when, in fine, the vessels are deprived of blood altoge- 
 ther. The question, it is true, arises as to the cadaverous con- 
 tractions exerted by galvanism; but other' facts prove again, 
 that the presence of blood in the vessels of the muscles is not 
 necessary to their contraction. Nevertheless, it is known that, 
 when there is fluid blood in a muscle, contraction, even after 
 death, puts the blood in motion, as if by a kind of exposition. 
 
 674. The fibres which were straight during the state of 
 relaxation, bend during contraction, forming very regular 
 sinuosities. These sinuosities or folds, before perceived' by 
 numerous observers, have been carefully examined by Messrs. 
 Prevost and Dumas, who have recognised these zigzags a* 
 being always produced in the same manner, and that the apex 
 of the angles, which are the points of the fibre that approach 
 each other outside of the line of con-traction, are also those 
 where the last traj^verse ramifications of the nerves ter- 
 minate. 
 
 675. During the contraction of the muscles there exists a 
 continual fibrillar agitation* in their thickness; some of the 
 fibres contract, while others are relaxed. It is to this cause 
 that we must ascribe the noise that is heard when the finger 
 
 * Roger, de perpetud fibr. must, palpitatione; Gott, 1760.-r-Wollaston, 
 .Croonian Lecture, in Philos. Trans.; Ann. 1810. 
 55 
 
424 GENERAL ANATOMY. 
 
 is applied to the orifice of the auricular canal, as well as that 
 which is perceived by the application of the stethoscope on 
 the muscle in action. This phenomenon is principally and 
 perhaps solely rendered appreciable in a muscle where the 
 action is ke'pt up for some time. It has only been observed 
 to exist, either by the help of the sight or hearing, in the exte- 
 rior muscles, and in the heart. 
 
 676. Certain muscles are capable of partial contraction. 
 This is at least seen in the experiments on living animals, and 
 in some cases of convulsion of the subcutaneous muscles. Is 
 this peculiar to the muscles which have several nerves? 
 
 677. The rapidity as well as the force of contraction 
 are extremely great; the rapidity is very great in the action 
 of running, in that of speaking fastj in that of playing on 
 stringed instruments, &c. This rapidity, in some cases, may 
 be carried to less than a third in point of time. The force of 
 the muscles when in action is enormous, and is sometimes 
 sufficient to rupture the tendons -or the bones, parts of the 
 body so capable of resisting rupture; it is always in propor- 
 tion to the number of muscular fibres, each of which possesses 
 its own force, which is a fraction of the total force. The elas- 
 ticity of the contracted muscles is particularly manifest in the 
 production of the voice. 
 
 678. It is difficult to determine the extent .of the contrac- 
 tion; it has been attempted on the principle of certain hypo- 
 thetical ideas as to the form of the primitive fibres, and it has 
 thus been estimated at one third the length of the fibre. Direct 
 observation demonstrates that Jhe shortening of the contracted 
 fibre, in the exterior muscles, is the fourth of its length; Messrs. 
 Prevost and Dumas have arrived at the same result by mea- 
 suring the angles, which are formed during.co.ntraction. How- 
 ever this may be, the extent of the contraction is always in 
 proportion to the length of the muscular fibres. When nothing 
 is opposed to the contraction of the muscle, it is capable of 
 producing a very great .shortening, examples of which are 
 seen in cases of fracture, and loss of substance in the bones 
 and members. 
 
 679. The conditions of muscular action are the life of the 
 
OF THE MUSCULAR SYSTEM IN GENERAL. 425 
 
 muscle and its communication with the circulatory and nerv- 
 ous centres, its integral state, and the action of an exciting 
 or stimulating influence. 
 
 Muscular action can not occur unless the circulation takes 
 place in the muscle; should the arteries or principal veins of 
 a part of the body be tied, its muscular action is considerably 
 weakened. The muscles, in order to act, must also commu- 
 nicate through the nerves, with the nervous centre; the inter- 
 ruption of this communication arrests the muscular action 
 more or less suddenly. It invariably and instantly stops the 
 influence of the nervous centre; but the muscle remains irrita- 
 ble from causes that act on it, or on the nerve to which it is 
 still attached. 
 
 680. The muscle must be in its integral state; the contu- 
 sion of the muscles, the inflammation of their cellular sheaths, 
 the accumulation of fat in the intervals of the fasciculi, &c., 
 are so many tircumstances that more or less oppose -the mus^ 
 cular action. The excessive distention of the muscular fibres 
 is sufficient to prevent their action; this is not altogether the 
 case with respect to their contraction. An extreme degree of 
 heat or cold, the immediate application- of opium on the mus- 
 cles, and many other substances, diminish the muscular irri- 
 tability in general, but have little effect, however, on galvanic 
 susceptibility. 
 
 681. To bring the muscle at all into action, it must be ex- 
 cited by some stimulant. The stimulants of muscular action 
 are: 1. Volition, or the action of the will; it acts on the muscles 
 through the medium of the nerves, but it only serves as a 
 stimulant to certain particular muscles, which for this reason 
 are called voluntary muscles; 2. Emotion or passion which acts 
 by the same means, but the action of which is extended to all 
 the muscles; 3. The irritation of the encephalon, of the spinal 
 marrow, or of the nerves, which in the first case, also acts on 
 all the muscles, but with more or less energy; 4. The stimula- 
 tion of some determined part, of the skin or the mucous mem- 
 brane, more or less remote from the muscles; 5. That of the 
 membrane which immediately, covers the muscles, as the in- 
 ternal membrane of the heart, the cellular sheath of the mus- 
 
426 GENEKAL ANATOMY. 
 
 cles, the serous membrane of the abdomen, &c. ; 6. Lastly, 
 the direct irritation of the muscle itself: it remains doubtful, 
 in this case, whether the exciting cause acts immediately on 
 the muscular fibre, or through the medium of the nerves. 
 What renders this last supposition the more probable, is that 
 the irritation of a part of a muscle produces the contraction of 
 the entire muscle itself. 
 
 682. The, cause of muscular action is, like that of all or- 
 ganic action, almost impossible to'determine: we know the 
 phenomena and conditions, beyond that, all is mere hy- 
 pothesis. This cause has been ascribed to the action of the 
 nerve, to that of the blood, to the reciprocal action of the 
 nerve and the blood in the muscle; and according to the doc- 
 trines prevailing at different periods, these opinions have given 
 birth to a great many different hypotheses, none of them have 
 accounted for the augmentation of the power of cohesion of the 
 muscle. . It is evident that during contraction there is a mo- 
 mentary increase of molicular attraction between the particles 
 of the fibre. If the plaited form assumed by the fibre be con- 
 sidered, as well as the connexion of the nervous filaments with 
 their plaits, it may readily be conceived that the nervous in- 
 fluence must share largely in the phenomenon of contraction. 
 
 683. Is irritability a power inherent in the fibrinous sub- 
 stance of the muscle, and does the nervous action only there 
 take place like any other excitant causing contraction? In this 
 hypothesis, the nerves would, in the voluntary muscles, only 
 fulfil the function of irritating .them; and with respect to the 
 muscles which, as the heart, do not contract voluntarily, 
 the nervous- action would not manifest itself under ordinary 
 circumstances. Or, on the other hand, has irritability its only 
 source in the nervous system? By this hypothesis, the nerves 
 would fulfil, with regard to the voluntary muscles, the double 
 office of rendering them irritable and of causing them to con- 
 tract; and, with regard to the involuntary muscles, the con- 
 traction of which is determined by local stimulants, it would 
 render them' only predisposed to this contraction. Or, lastly, 
 have the muscles an inherent power, (visinsita) and a power 
 borrowed from the nervous action (vis nervea)? It is almost 
 
OF THE MUSCULAR SYSTEM IN GENERAL. 427 
 
 impossible to answer these questions, or to choose between 
 these hypotheses with any reasonable motive of preference. 
 684. The, effects of muscular actfcn in the living body 4 are 
 to produce or to prevent the movement of the solid and liquid 
 parts, or even of the whole body, as the case may be. 
 
 The modes according to which the muscles exercise their 
 action, may be reduced to two: 1. The two extremities of the 
 fibres in action may remain equally stationary, as in the ac- 
 tion of the diaphragm, the muscles of the abdomen, the bucci- 
 nator, &c.; or be equally moveable, as in the sphincters, the 
 annular fibres of the stomach, the intestines, &c.; 2. One ex- 
 tremity of the fibres in action is more fixed than the other, so 
 that the more moveable one is (frawn towards the other, as in 
 the greater part of the muscles of the members;' particularly in 
 those of the fingers and toes; or else one extremity is abso- 
 lutely stationary, and the other absolutely i&oveablej as in the 
 muscles of the eye, the soft palate, &c. 
 
 685. The actions of the muscles that naturally take place 
 in the body, may be divided into two classes: voluntary and 
 involuntary. 
 
 The voluntary actions are those of all the muscles that ser.ve 
 the purpose of the skeleton both when stationary or in motion, 
 that contribute to the movements of the larynx, and to those 
 of the organs of sensation. All these muscles receive their 
 nerves directly from the spinal marrow. 
 
 The involuntary actions may be subdivided into three or- 
 ders; some are produced by the stimulus acting across a thin 
 membrane which immediately covers the muscles; such are 
 the movements of the alimentary canal, of the bladder, of the 
 heart, &c. ; others are produced by stimuli of an analogous 
 kind, but which are propagated by means of a connexion with 
 many other muscles: such are the movements of deglutition, 
 respiration, coughing, sneezing, fecal excrementation, emis- 
 sion of sperm, urinating, accouchement, &c. The others are 
 the movements of emotion or passion, such as laughing, cry- 
 ing out, &c. 
 
 Among the actions or movements of this second class, some 
 have been considered as semi-voluntary, or .as constituting an 
 
428 GENERAL ANATOMY. 
 
 intermediate class of mixed movements. It is in fact extreme- 
 ly difficult to establish a well marked distinction between the 
 voluntary movements, tWlt is to say, those under the perfect 
 control of the will, and the involuntary movements; for on the 
 one hand, there are few functions over which the will, and 
 above all the passions, do not exercise their empire; and on 
 the other, many of the voluntary movements become, by as- 
 suetude, almost involuntary; such, for example, are the move- 
 ments of the members which take place without conscious- 
 ness, and without exercise of the will during sleep; such are 
 those of the eyelids which take place even in opposition to the 
 will, when a foreign body approaches the eye; the difficulty 
 or the impossibility of moving simultaneously the superior or 
 inferior members, or the eyes, in a direction opposed to that 
 which they are ordinarily accustomed to, are moreover of this 
 character. The accidental irritation of the muscles, of the 
 nerves, or of the nervous centre, sometimes renders the con- 
 traction of the exterior muscles altogether involuntar} r ; other 
 affections render them immoveable in spite of the will. As to 
 the influence of the will on the movements regarded as in- 
 voluntary, it is evident in those of respiration, of vomiting, 
 and .ruminating; it even appears to be sometimes extended to 
 the movements of the heart, to those of the uterus, the iris and 
 the skin; it is true, that the influence of the passions on the 
 will itself must not be forgotten. 
 
 The movements that have been regarded as mixed, are more 
 especially those which, occurring in. general unconsciously, 
 and without the exercise of the will, may be modified by the 
 latter; of this character are those of the diaphragm. This name 
 is not so generally given to those which being habitually 
 voluntary, are exercised by habit and association, without be- 
 ing directed by the will, as movements by which the superior 
 members are balanced in. walking. 
 
 It is to be remarked that apoplexy and the other cerebral 
 affections generally paralyze the voluntary muscles only. 
 
 686. The varied muscular movements which take place in 
 the living body, are. in general either connected with each 
 other, in order to produce an identical action, or opposed to 
 
OF THE MUSCULAR SYSTEM IN GENERAL. 429 
 
 each other, to produce contrary actions: in the first case, the 
 muscles are called congeneric; in the second antagonist. An- 
 tagonism is much the most evident in the exterior muscles, 
 as, for instance, it is seen in the flexors and extensors; it is 
 less strongly marked in the interior or automatic muscles; 
 nevertheless, it is not altogether foreign to them; 'opposition 
 of the automatic and arbitrary muscles occurs at the natural 
 orifices, as is perceived between the excretory muscles, which 
 are involuntary, and the sphincter muscles which are volun- 
 tary. Antagonism every where presents this remarkable phe- 
 nomenon, that the Contraction of some muscles is accompanied 
 by the relaxation of another. The Congeneric or associated 
 muscles present another important phenomenon, which is, that 
 their contraction is simultaneous, and that, when a stimulus 
 is confined to one only, the rest nevertheless come into action: 
 thus when the throat, the orifice of the larynx, the anterior 
 angle of the vesical trigon, &c., are stimulated, all the muscu- 
 lar powers exercised in vomiting, in coughing, or in urinat- 
 ing, &c., are brought into action by the law of association 
 of the congenerous muscles, but at the same time aixl in con- 
 formity with the law of antagonism. In the last case the 
 sphincter and constrictor muscles of the neck of the bladder, 
 and of the ureter, are relaxed. 
 
 687. The muscles continue, some time after death, and 
 after circulation ceases, to be irritable and contractile by means 
 of divers stimuli. All the muscles do not preserve their irri- 
 tability during the same period; neither do they suddenly lose 
 their susceptibility to contraction, but cease at first to be e- 
 citable by certain stimuli; the anterior state of health, the kind 
 of death, the exterior circumstances before death, have a great 
 influence on the duration of the muscular irritability. Galen, 
 Harvey, and Haller, knew that the heart is in general the 
 ultimum moriens. Haller had established an order of cessa- 
 tion of irritability in the different muscles, and also perceived 
 several varieties in -that order. Zinn, Zimmermann, Ader, 
 Froriep, and particularly Nysten, have particularly studied 
 this subject. The varieties perceived by Haller, depend 
 greatly on the nature of the excitant; for instance; the heart 
 
430 GENERAL ANATOMY. 
 
 remains irritable much longer than any other muscle, by the 
 application of. mechanical agents, and the muscles of the 
 skeleton, on the contrary, by galvanic irritation. Galvanic 
 irritation acts more efficaciously by not comprehending the 
 exterior muscles, than by comprehending them with the nerve 
 in the galvanic circuit. The contrary occurs with the inte- 
 rior muscles. 
 
 The order established by Nysten, with respect to the suc- 
 cessive extinction of irritability in the bodies of decapitated 
 individuals, is as follows: 1st, the aortic ventricle of the heart; 
 2d, the large intestine, the small intestine and the stomach; 
 3d, the urinary bladder; 4th, the pulmonary ventricle; 5th, 
 the oesophagus; 6th, the iris; 7th, the exterior muscles; Sth, 
 the right auricle, and lastly, the left auricle. 
 
 Muscles or parts of muscles, separated from the living body, 
 retain their irritability for some time. They present, in this 
 respect, variations analogous to those which have just been 
 indicated. Contraction under these two circumstances evi- 
 dently takes place without an afflux of blood. 
 
 688. When irritability is on the point of being extinct or 
 exhausted in the muscles, irritation no longer determines any 
 general or extensive contraction of the entire muscles, their 
 bundles or fasciculi; but it remains limited to the points irri- 
 tated, which swell by the flexuosity of which it becomes the 
 seat. This last description of irritability which survives the 
 nervous action, appears to me to be precisely of the same kind 
 as that observable in the fibrine.of the blood; this is in reality 
 the vis insita of the muscular fibre. 
 
 689. The kind of death, the previous state, and the sur- 
 rounding circumstances, exert an influence on the cadaverous 
 irritability. The state of paralyses and of hemiplegia does not 
 prevent the muscles from being irritable in the cadaver, by 
 galvanism. Diseases have a much greater influence on the 
 cadaverous irritability by their progress and continuance, than 
 by their nature; chronic diseases alter'this property much 
 more than acute ones, and among the chijpnic diseases, those 
 in which nutrition is most impaired, are'most fatal to muscular 
 action. The most muscular persons are not those in whom mus- 
 
OF THE MUSCULAR SYSTEM IN GENERAL. 431 
 
 cular irritability continues longest after death. This duration 
 varies from one hour to twenty-four hours, or thereabout. 
 
 690. Finally, after all irritability, general or local, has 
 ceased in the body deprived of life, cadaverous stiffness en- 
 sues.(124) It is an invariable phenomenon, whatever may 
 have been said of it by Haller and Bichat, but it varies in its 
 intensity as well as duration. This contraction or stiffness, 
 has its seat in the muscular system, and is independent of the 
 nervous system; it takes place only when this system has 
 ceased to possess any galvanic irritability. The section of the 
 nerves, the state of hemiplegia and the oblation of the nervous 
 centre, do not hinder it from manifesting itself. It is the last 
 effort of muscular contractility. In cold blooded animals, in 
 which nervous excitability continues fora long time, cadaver- 
 ous stiffness occurs late and continues but a short time, where- 
 as, in warm-blooded animals, it takes place soon after death 
 and continues a long time; in which nervous excitability is of 
 short duration. Cadaverous stiffness seems to be analogous to 
 the contraction of the fibrinous coagulum of the blood, and 
 like this, only ceases when putrefaction commences. It may 
 be considered, when joined to the coldness that always ac- 
 companies it, as a certain sign of death. If a muscle in a 
 state of stiffness be immersed and preserved in alcohol, that 
 stiffness will continue for an indefinite period. 
 
 693. Other moving properties have been attributed to the 
 muscles. Galen recognised in them a tonic force, indepen- 
 dent of life; elasticity has likewise been ascribed to them; Hal- 
 ler ascribed to them contractile force in general, as well as 
 dead force; Sympson and Whytt attributed tonicity or tonic 
 force to them; Bichat, in addition to voluntary contractility, 
 and irritability or voluntary contractility, attributed to them 
 insensible organic contractility, that is to say tonicity. 
 
 The muscles are extensible, they are retractile 'also, and this 
 independently of their contraction by irritation. In the state 
 of sleep and of repose the muscles furnish generally to the dif- 
 ferent parts of the body, mean attitudes depending on their 
 proportionate length, and consequently on their tension, on 
 their force, and on the manner, more or less efficacious, in 
 56 
 
432 GENERAL ANATOMY. 
 
 which this force is applied. The -same thing takes place in 
 paralysis determined artificially, by cutting all the nerves of 
 a member. In paralysis arising from cerebral affection, and 
 in contraction of the limbs, the attitude is sometimes different ; 
 the flexion being sometimes carried to a great extent. But 
 here arises a doubt, which is, whether the cause of paralysis 
 has been equally extended to all the nerves of the part; if in- 
 deed this cause does not originate in the tonic contraction of 
 some muscles. In the dead body the muscles remain contrac- 
 tile, and give a determinate attitude to all parts of the body, 
 until the cadaveric stiffness subsides. 
 
 693. The muscles are possessed of sensibility, but only in 
 a moderate degree. In the state of health they produce little 
 more than the sense of fatigue during and after their action, 
 when it has been prolonged. When the action has been very 
 long continued and violent, it produces a painful sensation. 
 The same thing occurs in case of inflammation of their tissue 
 or of their cellular sheaths. Cabanis and Dr. Yelloly have 
 stated cases of diseases in which the muscles were insensible. 
 
 694. The circumstances which manifest a continual change 
 of particles in muscular nutrition are not very evident; the 
 fact is nevertheless probable: it would seem to be the globu- 
 lar part of the blood that furnishes the materials for it. The 
 effects of exercise on nutrition, the augmentation and colora- 
 tion of the muscles, and the opposite effect of rest too long 
 continued, are well known. Paralysis produces an effect still 
 more remarkable on their diminution. The quantity and 
 quality of nourishment have a great influence on the volume 
 as well as strength of the muscles. Certain consumptive dis- 
 eases, such as phthisis, have a strong influence on muscular 
 atrophy. We are ignorant whether, in this case, there is a 
 diminution of volume only, or a disappearance of the fibres 
 altogether. 
 
 695. In the embryo, the muscular tissue is not distinct 
 from the cellular tissue; they are confounded in a common 
 gelatinous mass. At a period but little remote from the mo- 
 ment of conception, the action of the heart presents a consi- 
 derable degree of development in the muscular tissue of that 
 
OF THE MUSCULAR SYSTEM IN GENERAL. 433 
 
 organ. About two months after conception, the muscles of the 
 skeleton have acquired distinct fibres; towards the fourth 
 month they begin to execute contractions. According to Bi- 
 chat, the muscles of the foetus possess a smaller degree of irri- 
 tability, or at least less galvanic susceptibility, than that of 
 individuals who have respired. Experiments made by Meckel 
 on some animals have offered results contradictory to those 
 of Bichat. 
 
 During childhood the muscles continue small in volume in 
 proportion to the nerves and adipose tissue. At this age too, 
 the muscular flesh is not only less red, but is more gelatinous 
 and less fibrinous than in adult age; the motions are easy, 
 prompt and feeble. 
 
 The muscles, which are of a vermilion red in the adult, be- 
 come pale, yellowish and livid in old age; contractions at this 
 period become difficult, feeble and slow. 
 
 The irritability and action of the muscles in females, com- 
 pared with those in males, present nearly the same difference 
 as those of the adolescent compared with those of the adult: 
 that is, a greater degree of irritability or susceptibility of move- 
 ment, a weaker action and less capable of a continued action. 
 
 Between the races of mankind there exist differences in 
 muscular power, which, according to the experiments made 
 by Peron with the dynamometer, is in favour of Europeans, 
 whose health and strength are the result of abundant and 
 wholesome diet and habitual occupation, while the inhabitants 
 of Timor, New Holland, and Van-Diemen*s Land, exposed 
 as they are to every kind of privation, have less muscular 
 strength. 
 
 696. When the muscles are exposed to view* by a wound 
 of the skin, the aponeurosis and the cellular sheaths, and these 
 parts, are brought together again with precision, there occurs 
 in the solution of continuity an effusion of organizable fluid; 
 at first slightly adherent to the muscle and afterwards esta- 
 blishing an organic reunion. The same thing happens when 
 
 * B. Fr Schnell, Prass. Auter rieth, de natura reunionis musculorum vol- 
 
 neratorufii. Tubings, 1804. 
 
434 GENERAL ANATOMY. 
 
 muscles, divided crosswise, in amputation for example, are 
 covered over again by the flaps of skin; only the agglutinating 
 matter is from the commencement very closely attached to 
 the truncated extremity of the muscles. When muscles are 
 cut crosswise, and not covered by flaps of skin, there soon 
 forms at their extremity suppurating granulations, and after- 
 wards a cicatrice; these phenomena, and particularly the last, 
 are more tardy when the muscles are only laterally denuded. 
 In all these cases, at whatever period an inflamed wound is 
 examined, whether the inflammation be adhesive or suppura- 
 tive, the cellular sheaths of the muscles and of their bundles 
 only are changed; no change whatever is perceptible in the 
 muscular fibres themselves. It is proper to observe, however, 
 that in this case the fibres are deprived of the greater part of 
 their irritability. 
 
 697. When a muscle is cut across, a considerable separa- 
 tion takes place between the edges of the division, and always 
 greater than the wound sustained by the skin. When the 
 edges of the external wound have been brought together, and 
 have united, the ends of the muscle remain separated, at first 
 filled with an organizable liquid, which afterwards becomes 
 vascular, soft, which contracts a little and slightly diminishes 
 the distance which existed between the ends of the muscles, 
 and at last becomes more or less firm and resisting. This in- 
 termediate substance, when its organization is completed, has 
 sometimes the appearance of cellular tissue, frequently that of 
 ligamentous tissue, and sometimes that of sub-cartilaginous 
 coriaceous tissue, but never that of muscular tissue. At some 
 period of the formation we are now examining, it is always 
 found that the muscular fibres and fasciculi are foreign to it, 
 and that it is only the reunion of the cellular tissue which 
 forms sheaths to them. A muscle which is reunited in this 
 manner, presents a kind of aponeurotic tendinous intersec- 
 tion; it is a kind of digastric muscle, the two bellies of 
 which are living and irritable, whilst the intermediate sub- 
 stance fulfils the functions of a tendon which more or less 
 resists or gives way to distention. This intermediate sub- 
 stance is not irritable either by mechanical stimulants or gal- 
 
OF THE MUSCULAR SYSTEM IN GENERAL. 435 
 
 vanism. However, when irritability is well manifested and 
 the galvanic action is strong, the irritation applied to one of 
 the parts of the reunited muscle, is propagated through the 
 cicatrice, which however does not contract with the other 
 part of the muscle. We are ignorant, if during life, and by 
 the action of the will, the parts of a muscle divided across 
 and united by a cicatrice, both contract. It is evident that 
 the greater the separation between the muscles at the time 
 the mediate reunion has occurred, that also the means of re- 
 union will be longer and more extensible, and the more will 
 the muscles have lost of their extension and power. Under 
 the most favourable circumstances, movements at first are im- 
 possible and afterwards feeble and uncertain until the means 
 of union have acquired their proper degree of firmness. 
 
 All that has just been advanced on the reunion of the mus- 
 cles that have been cut across, is applicable to their rupture 
 through effort. 
 
 When a transversal wound of the muscles or of the skin has 
 remained separated and gaping, there is found throughout its 
 extent, a layer of suppurating granulations, and afterwards a 
 cicatrice more or less extensive, under which the two ends of 
 the muscle remain separated. 
 
 In the latter case, as well as the former, the intermediate 
 substance, too long and too extensible, which formed the re- 
 union of the divided muscle, has sometimes been denuded and 
 cut out; by afterwards bringing into contact the divided parts 
 and retaining them in that state sufficiently long, a short and 
 firm reunion has been obtained and motion restored to parts 
 which had almost entirely lost it. 
 
 698. The muscles are subject to variations and to mal- 
 conformation; monstrous foetus, acephalus* and others, have 
 been seen, deprived of all the muscles or of all those apper- 
 taining to a particular member at least, these organs being re- 
 placed by infiltrated cellular tissue. 
 
 We observe more frequently the defect or absence of single 
 muscles. 
 
 * Beclard, Memoir es sur les foetus acfphaks. 
 
436 
 
 GENERAL ANATOMY. 
 
 Supernumerary muscles, and others divided into several 
 distinct parts, are often found; muscles united which ordina- 
 rily are separate; others, longer or shorter than is natural, 
 which changes their attachments and modifies their functions; 
 all these varieties are original or primitive. 
 
 The diminution or augmentation of the volume of the mus- 
 cles are, on the contrary, owing generally to accidental causes. 
 Repose and paralysis diminishes their size, exercise augments 
 it. 
 
 Muscular ruptures* happen, either by the action of the an- 
 tagonist muscles, or by another power which distends a relaxed 
 muscle, or by the action of the ruptured muscle itself; in this 
 last case, the rupture most commonly occurs at the union of 
 the tendinous or aponeurotic parts with the fleshy fibres, a 
 small number only of which are torn. In case of rupture, 
 there occurs a separation, attended with noise and pain, and 
 more or less extensive and deep, and an effusion of blood more 
 or less abundant in the solution of continuity and in the sur- 
 rounding cellular tissue. The interior muscles, and especially 
 the heart, are sometimes ruptured by their contraction. 
 
 The displacement! of the muscles, admitted by Pouteau, 
 Portal, and other pathologists, is scarcely possible, unless the 
 enveloping aponeurosis be severed. 
 
 699. The muscles present many alterations of colour, 
 consistency, and cohesion. 
 
 In rheumatism, a gelatiniform liquid is sometimes found on 
 the surface, in the interior, and in the thickness of the cellu- 
 lar sheaths. 
 
 In cases of long standing paralysis, the muscles are emaci- 
 ated, white, and sometimes very fat. We have already seen 
 above, (168) that the transformation of the muscles into fat, 
 was rather apparent than real. It results from the paleness oc- 
 casioned by the atrophy of the muscle, conjointly with the 
 accumulation of fat between the fasciculi of fibres. 
 
 * J. Sedillot, memoire sur la rupture musculaire, in M^m. et prix de la 
 Soc. de med. de Paris 1817. 
 
 j- J. Hansbeand, Diss. luxationis sic dictse muscularis refutationem aistens, 
 Berol. 1814. 
 
OF THE INTERIOR MUSCLES. 437 
 
 Accidental productions, either of analogous tissues or mor- 
 bid tissues, are rarely observed' in the muscles. Accidental 
 bones are, however, sometimes found in them. I once found 
 a mixed osseous and cancerous production, occupying the 
 muscles of the calf of the leg. The leprous cysticercus, 
 cysticercus cellulosx of Rudolphi, is sometimes found in the 
 muscles of man, and often in those of swine. Accidental 
 production of the muscular tissue is very rare, if indeed it 
 ever takes place. An affinity has, however, been established 
 between the sarcoma and the muscular flesh. It is also said 
 that accidental muscular productions have been seen in the 
 serous membranes, in the bones, and in the ovaries: it appears 
 that the observers have suffered themselves to be deceived by 
 appearances. 
 
 The development of the muscular texture in the uterus, 
 during pregnancy, and the disappearance of that texture after 
 accouchement, is somewhat analogous to an accidental produc- 
 tion. 
 
 700. The functions of the muscles present varieties and 
 alterations, some of which have their seat and their cause in 
 the muscular tissue itself, and others in the nervous system. 
 These varieties and these changes are, for the most part, dif- 
 ferent in the two species of muscles, and almost all are pecu- 
 liar to the full, external, voluntary muscles, or to those of the 
 animal functions. 
 
 SECTION II. 
 
 OF THE INTERIOR MUSCLES. 
 
 701. These muscles, which are also called hollow muscles, 
 involuntary muscles, and muscles of vegetative or organic 
 functions, have no name appropriated to themselves, each of 
 them bears that of the organ it concurs in forming. 
 
 702. These muscles are, 1, the heart; 2, those which dou- 
 ble the mucous membrane of the alimentary passages through- 
 
438 GENERAL ANATOMY. 
 
 out their extent; those which line the urinary and genital pro- 
 longation of the same membrane, form the bladder, the sper- 
 matic vesicles, and the uterus; those of the pulmonary pro- 
 longations of this membrane which form the bundles of the 
 trachia and bronchse. The sphincters, which are found at the 
 orifices of the alimentary canal and the urinary and genital 
 passages, may be regarded as intermediate to the two classes 
 of muscles. Nearly the same is the case with respect to the 
 texture, and more especially the functions, of the muscles of 
 the skeleton, which are subservient to digestion, respiration, 
 generation, and the urinary excretion. There is not, then, 
 any very marked distinction between the two classes of mus- 
 cles. 
 
 703. The muscles in question are placed in the interior; 
 some situated immediately under the internal tegument, and 
 in particular, the heart, is situated very deeply and distant 
 from the two surfaces, of which it is entirely independent. 
 
 The volume of these muscles is very inconsiderable when 
 compared with that of the exterior muscles; they all form the 
 parietes of canals and of reservoirs. 
 
 704. These muscles are disposed in layers or in bundles 
 crossing each other. 
 
 Throughout the whole extent of the alimentary canal, there 
 are circular or annular fibres, and longitudinal fibres, each 
 forming a distinct plane, more or less complete and thick. 
 
 In the reservoirs, as well as in the heart, the fibres are dis- 
 posed in layers and bundles which cross each other obliquely, 
 they have an arched form, the extremities of which are fixed 
 to the sides of the aperture of the organ. The bundles of 
 fibres in these organs cross each other, and are united in the 
 manner of plexuses. This arrangement is less marked in the 
 alimentary canal, where the muscular layers cross each other 
 at right angles. 
 
 The muscular fibre of the interior muscles is of a grayish 
 white in most of them, and red in the heart only. This fibre 
 differs in no other respect from that of the exterior muscles. 
 The uterus alone in this respect presents a well-marked differ 
 ence, and characters entirely peculiar. 
 
OF THE INTERIOR MUSCLES. 439 
 
 705. The cellular tissue of the interior muscles is not so 
 abundant, but is more compact than that of the other muscles. 
 Fibrous or ligamentous tissue is only found in the heart, where 
 it forms rings for the orifices of the ventricles, cords or ten- 
 dons for the fleshy columns of these cavities, aponeurotic ex- 
 pansions which constitute in a great measure thetricuspid and 
 bicuspid valves of the auriculo-ventricular orifices, and cords 
 in the borders of the semi-lunar valves of the arterial orifices. 
 Bichat, who only speaks of the tendinous cords of the fleshy 
 columns, had before indicated that tbere exists differences be- 
 tween them and the tendons. In the other parts nothing is 
 found analogous to the ligamentous tissue, except the submu- 
 cus fibro-cellular tissue, to whif h are attached the subjacent 
 muscular fibres. 
 
 The interior muscles appear to possess more blood-vessels 
 than the exterior. M. Ribes, however, asserts the contrary. 
 The greater part of the nerves of these muscles, which how- 
 ever are not abundant, belong to the great sympathetic; seve- 
 ral are furnished by the pneumo-gastric, and some few by other 
 nerves of the spinal marrow. 
 
 706. The irritability of the interior muscles presents the 
 same phenomena as that of the other muscles, except the 
 fibrillary agitation, which has only been observed to exist in 
 the heart. 
 
 The internal muscles possess less irritability than the exter- 
 nal, depending on nervous influence. 
 
 Mechanical irritation is much more efficacious than galvanic 
 action in determining their contractions. Galvanic irritation 
 acts but slightly on them through the medium of the nerves. 
 Nevertheless, the cardiac nerves and the heart being compre- 
 hended in a galvanic circle, the continued action of this agent 
 determines movements in the organ. 
 
 The irritability or susceptibility of contraction of the inte- 
 rior muscles, is the more remarkable, from its being materially 
 excited by local agents, which act on the fibre through the 
 medium of the membrane that covers it; at other times the 
 cause acts by sympathy: thus the titillation of the throat, the 
 presence of a bougie in the urethra, of a suppository in the 
 57 
 
440 GENERAL ANATOMY. 
 
 anus, induce the action of the stomach, the bladder, and the 
 intestines. The will has little control over the contractility 
 of these muscles; yet the czsophagus, the rectum, the bladder, 
 and even the stomach are not altogether independent of it; it 
 appears even that the uterus, at least in birds, is also some- 
 times subject to the will. The small intestine, on the con- 
 trary, is not at all under its control ; the heart is equally in- 
 dependent of it. And yet the case is still cited of an English 
 captain, reported by Dr. Cheyne, and since related by all 
 physiologists, and that of the late Dr. Bayle, reported by M. 
 Ribes, who could at pleasure slacken or suspend the move- 
 ments of the heart. But if the interior muscles are not sub- 
 ject to the ordinary influencegof the will, the strong affections 
 of the soul, and lively emotions of the mind, influence them in 
 the most evident manner. 
 
 Haller, in admitting that muscular power is inherent in the 
 muscles, and that nervous action is only the exciting cause of 
 it, was led to admit, and most of his successors have admitted 
 still more positively than himself, that the interior muscles 
 are independent of the nervous action, at least in their ordina- 
 ry and regular movements. The experiments of Legallois 
 afterwards induced the admission of a directly contrary opin- 
 ion. The more recent experiments of M. Cliff,* and those of 
 M. Wilson Philip,! and the comparative observation of other 
 animals, of monstrous embryos and foetuses, were calculated to 
 modify both these conclusions. Known facts demonstrate, in 
 effect, that the interior muscles are independent of the nervous 
 spinal marrow, in animals and monstrous foetuses which have 
 none, as well as in embryos which as yet have acquired none; 
 little dependent on it in young animals in which its influence 
 is not of long standing, and in animals of an inferior order, in 
 which the nervous action has not a well determined centre; 
 but are, on the contrary, dependent on that organ in the adult 
 man; they are moreover greatly influenced by its lesions, and 
 still more so by sudden lesions than by slow alterations. 
 
 * Philos. trans. Ann. 1815. 
 
 \Anexptr. Ing. into the laws of the vital functions, &c. Loml. 1818. 
 
OF THE EXTERIOR MTJSC,L 441 
 
 707. When the interior muscles contract, they sometimes 
 draw into simultaneous and associated action all the exterior 
 muscles which can contrihute to the accomplishment of their 
 function: thus in coughing, sneezing, vomiting, defecation, ac- 
 couchement, &c., a number more or less considerable of mus- 
 cles of the skeleton act by association, with' interior muscles. 
 The interior muscles have no real antagonists like the exte- 
 rior muscles, all their fibres tending to one sole and common 
 end, the diminution of capacity of the cavity which they form. 
 However, we may consider as such, 1st, the foreign substances 
 thai; keep asunder the parietes of the organs formed by these 
 muscles; 2d, the various parts of a particular hollow organ: 
 for example, the auricles with relation to the ventricles; the 
 body of the uterus, and that of the bladder with respect to the 
 neck or orifice of these organs ; 3d, the two muscular layers in 
 the alimentary canal in the peristaltic motion ; the contraction 
 of the longitudinal fibres determining, by pushing forward the 
 faeces, the extension of the annular fibres. Now, there hap- 
 pens in this precisely what takes place in all antagonism: the 
 contraction of one muscle coincides with the relaxation of its 
 antagonist, and vice versa; 4th, finally, the interior muscles 
 find antagonists in the exterior muscles. These muscles have 
 no determined fixed point: those which are annular, contract 
 on themselves; those which are longitudinal, however, have 
 this point in the orifices of the alimentary canal; those of the 
 reservoirs, as the bladder and uterus, as well as those of the 
 heart, have also a fixed point, better determined, in the orifice 
 of these organs. 
 
 SECTION III. 
 
 OP THE EXTERIOR MUSCLES. 
 
 708. These muscles are also called voluntary muscles, mus- 
 cles of animal functions, of animal life, muscles properly so 
 called. It is these that constitute the greater part of the mass 
 of the body. 
 
442 GENERAL ANATOMY. 
 
 709. They are very numerous; there are from three to four 
 hundred of them, but this number has been variously stated. 
 Some regarding as several muscles what others have repre- 
 sented as bundles of an individual muscle. 
 
 710. Each muscle has its proper name, but this nomen- 
 clature has greatly varied. There is scarcely a single muscle 
 which has not received more than one, name, some have re- 
 ceived as many as a dozen. 
 
 The denomination of the muscles has been derived from 
 several considerations: numerical order has been applied to 
 them, thus when several muscles belong to the same part, the 
 same region, or same action, &c.; they have been distinguished 
 by the names of numbers, as the radial, the adductor, the inter- 
 osseous muscles, have been distinguished by first, second, &c. 
 Before James Sylvius, almost all the muscles were thus dis- 
 tinguished by the name of numbers. Some have adopted as sur- 
 names, their anterior, posterior, superior, inferior, superficial, 
 deep-seated, &c., situation, or they have been distinguished by 
 the name of the part they move, or the region they occupy, as 
 the palpebral, occular, labial, pectoral, dorsal, abdominal, crural 
 muscles, &c. Others are distinguished, according to their ex- 
 tent, or their volume, by the epithets great,small, mean, slender, 
 vast, wide, long, short, &c. Others have been named rhom- 
 boidal, square, triangular, scalenus, &c., in conformity with 
 the figure it was imagined they possessed; or else they have 
 been called splenius, by being compared with the spleen, or a 
 compress, solearis because of their resemblance to the fish 
 called a sole, or to the sole of a shoe. Certain muscles have 
 been named with reference to their direction, right, oblique, 
 transversal, spiral; after their texture and their composition, 
 they have been named biceps, triceps, complexus semi-ten- 
 dinosus, perforans, perforatus, &c. Other muscles have been 
 denominated according to their insertions, either from one of 
 them only, as the pterygoidi, peronei, zygomatici, &c. ; or from 
 two, as the stylo-hyoideus, sterno-hyoideus; or from a greater 
 number, as the sterno-cleido-mastoideus. Others again have 
 been named according to their use, flexors, extensors, eleva- 
 tors, abductors, depressors, pronatores, supinatores, &c.; finally, 
 
OF THE EXTERIOR MUSCLES. 443 
 
 even these are not all the considerations on which the nomen- 
 clature of the muscles is based. 
 
 Scarcely any of these considerations are absolutely useless to 
 the knowledge of the functions of the muscles; nevertheless, 
 the most useful are, without doubt, the movement itself, the 
 insertions, the region occupied by the muscle, its direction, 
 &c. It would matter but little how numerous these bases 
 were, provided they always furnished names that were proper, 
 distinct and short, even though not very significative; but 
 almost all the names of the muscles are names composed of 
 several of the circumstances indicated. Thus we find in the 
 muscular nomenclature, the names obliquus externus abdomi- 
 nis, rectus anticus capitis longus, radialis externus primus, 
 rectus femoris anticus, interosseus dorsalis manus primus, &c. 
 This inconvenience, joined to that resulting from the multi- 
 tude of different names given by various anatomists to the 
 same muscle, induced M. Chaussier* to propose a reform in 
 anatomical language, and especially in that of myology. This 
 reform in the names of the muscles consisted in giving to each 
 of them a name which expresses solely and constantly the two 
 opposite points of attachment, designated commonly under 
 the names of origin and of insertion; but the able author of 
 this project found it impossible to give names which were not 
 at the same time, a pretty large number of them at least, com- 
 posed of some others of the circumstances indicated above. 
 M. Dumast endeavoured to modify the nomenclature of M. 
 Chaussier by indicating in his names all the points of attach- 
 ment of the muscles. M. Dumeril,:j: also engaged in the re- 
 form of the anatomical language, by taking for the root of this 
 language the Greek or Latin names of the bones and of the 
 viscera, and by merely varying the termination of these names 
 for the varipus other organs and for the regions. The termina- 
 tion of the muscles was ien ; thus the name occipito frontien, 
 
 * Exposition sommaire des muscles du corps humain. Dijon., 1789. Ta- 
 bleau des muscles de fhomme. Paris, 1797. 
 
 f Systeme mtfhodique de nomenclature et de c lass i-ficat ion des muscles du 
 corps humain, etc. Montpillier, 1797, in 4to. 
 
 j Magasin Emydoptdique. 
 
444 GENERAL ANATOMY. 
 
 without joining to it the word muscle, designates in this 
 nomenclature, the occipito frontalis. Vicq. d'Azyr had 
 equally directed his views to the necessity of reforming the 
 anatomical language; he did not execute his project. Doctor 
 Barclay also engaged in this object, and directed his special 
 attention to giving proper and precise names to the different 
 regions of the body. M. Schreger* has collected together 
 most of the anatomical names employed up to his time, in a 
 voluminous synonymy, where is found almost as many names 
 to some organs, as there are treatises on anatomy. The fear 
 of contributing to the confusion, which is augmented almost 
 every time that a new treaty makes its appearance, ought to 
 induce the anatomists to make use of names already in use, in 
 choosing from among them those that are best known, the 
 most simple and the most significant. 
 
 711. According to their situation and their destination to 
 move any particular part, the exterior muscles are distin- 
 guished by those of the skeleton and the bones, by those of 
 the larynx, and by those of the organs of the senses and the 
 skin; several exterior muscles belong also to the orifices of 
 the digestive, respiratory, genital and urinarypassages, and 
 are there insensibly confounded with the interior muscles. 
 
 The muscles of the skeleton are situated in the trunk and 
 in the members: in the members they form considerable 
 masses, and are elongated; in -the trunk they are broad, nu- 
 merous in the back and the abdomen, less so in the thorax, 
 and still less so about the cranium. 
 
 712. The muscles vary greatly in volume, some are great 
 or voluminous, others are moderate in size, others small, and 
 others again very small. 
 
 713. All the muscles are in pairs, except the diaphragm, 
 the sphincters of the mouth and anus, the arytjienoidasus, 
 and often the levator uvulae; all, except the diaphragm, are 
 symmetrical, or similar on both sides, with the slight differ- 
 ence ordinarily observable in the volume of the two lateral 
 sides of the body. 
 
 * Synonyjala anaiomica, aud. Chr. II. Th. Schreger. Furthii, 180. . 
 8vo. 380 pages. 
 
OP THE EXTERIOR MUSCLES. 
 
 According to their form the muscles are moreover distin- 
 guished by the terms broad, long and short. 
 
 The broad muscles belong to the trunk; some of them ex- 
 tend from the trunk to the members, and are then elongated 
 in this last part of their extent. 
 
 The long muscles appertain to the members, and are in ge- 
 neral disposed in layers, the most exterior being the longest 
 and the straightest, the more profound being much shorter 
 and more oblique: a disposition important to be known in the 
 practice of amputations, since the muscles, unequal in length, 
 must contract unequally. 
 
 The short muscles are met with in the trunk and in the 
 members, near the articulations. 
 
 714. The direction of the muscles is that of a line ex- 
 tended, passing through their centre, from one extremity to 
 the other; it is often very different from that of its fibres, and 
 this last is the most important circumstance. When all the 
 fibres are straight and parallel to each other, the power of the 
 muscle, which is equal to the sum of the power of all the 
 fibres, operates in a manner parallel to the direction of these 
 fibres. But if the fibres are oblique with respect to each 
 other, the intensity and the direction of the power will be 
 different. 
 
 715. In general there is perceived in each muscle a body 
 or belly, and two extremities, the one of origin, the other of 
 insertion. The body is the fleshy part, the extremities are 
 ordinarily tendinous: the extremities are also frequently dis- 
 tinguished into point of origin, of adhesion or stationary point, 
 and in moveable point or of insertion; but many of the mus- 
 cles will not accommodate themselves to this description. 
 Those to which it would best apply are certain muscles of the 
 members, which are elongated, swelled in the middle, because 
 of the disposition of their fleshy fibres; formed of a short ten- 
 don at their superior extremity, generally the most fixed, and 
 of a long tendon at the other extremity, generally the most 
 moveable. But in these muscles, the movement may be divid- 
 ed between the two points, and sometimes may even be en- 
 tirely executed by the point most elevated. 
 
446 GENERAL ANATOMY. 
 
 716. Certain muscles form one sole fleshy body between 
 the two attachments; others, on the contrary, are formed of 
 very distinct bundles, which might be taken for so many mus- 
 cles; such, in particular, are the masseter, the deltoid, the sub- 
 scapulary, the glutseus muximus, &c. 
 
 717. There are muscles which in their whole extent re- 
 main simple and distinct, and others which are divided into 
 several parts, or confounded with others at one of their extre- 
 mities: thus, some mu'scles, simple at their insertion, are se- 
 parated, at their origin, into two or three parts: such are the 
 biceps and the triceps; such are also the sterno-mastoideus and 
 the pectoralis major, which for this reason some authors have 
 considered as composed of two muscles each; thus the com- 
 mon extensor and flexor muscles of the fingers and toes, though 
 simple at their origin, are divided at their insertion into seve- 
 ral parts. The serrati transversi and other muscles which are 
 attached to the ribs by digitations, are also nearly in the same 
 state. The muscles which have a common origin may be 
 compared to those of this description, as the muscles that are 
 attached to the ischium, as well as those with a common inser- 
 tion, as the latissimus dorsi and the teres major. 
 
 718. There are again muscles the composition of which is 
 different: such are several of the spinal or vertebral muscles, 
 and particularly the transversalis spinse, the longissimus dorsi, 
 and sacro lumbalis; they each result from many muscular 
 bundles, distinct at the extremities and confounded at the cen- 
 tre, in such a manner that each portion of muscle, though sin- 
 gle at one extremity, terminates at the other with two parts; 
 and reciprocally each of the latter is attached to a double por- 
 tion of the opposite extremity: these muscular bundles suc- 
 ceeding each other, and uniting with each other laterally, there 
 results from it a very long muscle, composed of short bundles, 
 distinct at their extremities, and united laterally in their mean 
 part. Each bundle being closely united with the two bundles, 
 can not contract without the latter entering into action at the 
 same time, so that the movement is always communicated at 
 once to several vertebrae or ribs: a disposition altogether in 
 
OP THE EXTERIOR MUSCLES. 447 
 
 conformity with that of the hones, which are always to be 
 moved, several of them simultaneously. 
 
 719. The muscles of the skeleton, and these are the most 
 numerous, have their two extremities attached to the perioste- 
 um and to the surface of the bones by tendons or aponeuroses. 
 The muscles of the larynx are attached in the same manner, 
 to the cartilages and perichondrium. The muscles which ex- 
 tend from the skeleton to the organs of sense, and are inserted 
 into cartilages, are besides provided with tendons at both ex- 
 tremities ; those which are attached to the teguments are, on 
 the contrary, destitute of tendons at their insertion in the der- 
 mis. 
 
 Besides the tendons and aponeuroses of attachment which 
 are found at the extremities of most of the muscles, some of 
 them also present tendons or aponeuroses of intersection, which 
 occupy some point of their extent, and divide them into seve- 
 ral fleshy bodies. Of this description are the maxillar digas- 
 tric and cervical digastric muscles, which are divided, by ten- 
 dons, into two very distinct bodies; such are also the sterno- 
 hyoideus, scapulo-hyoideus, the rectus abdominis, &c. the 
 fleshy body of which is divided by aponeuroses. 
 
 720. In a great many of the muscles the fibres are straight, 
 and obviously parallel from one end to the other. In several 
 muscles, the fleshy fibres, all parallel, extend obliquely be- 
 tween two aponeurotic tendons expanded on two opposite 
 faces of the fleshy body; such is the cruralis anticus. It was 
 muscles of this description, without doubt, that induced Gas- 
 sendi to compare the muscles generally to a tackle of pullies. 
 Other muscles are radiated, as the great pectoralis major, and 
 the latissimus dorsi, the fibres of which, while spread at their 
 origin, are collected into a thick bundle towards their inser- 
 tion; as the glutaeus medius, and glutaeus minimus, whose 
 fibres terminate successively on an aponeurotic expansion. 
 In others, the fibres are extended thus obliquely from their 
 origin from a bone to the side of a tendon: these muscles are 
 called semi-pennate; of this description are the peronae. 
 Others are pennated, the fibres passing obliquely on the two 
 sides of a tendon; in some others, very analogous to these 
 5S 
 
GENERAL ANATOMY. 
 
 last, the fibres form two planes, which are inserted on the two 
 faces of a middle aponeurosis; such as the temporal muscle. 
 Other muscles are still more compound, as the deltoid, the 
 masseter, &c. which result from the union of several penni- 
 form bundles. 
 
 721. The texture of the exterior muscles always results 
 from bundles more or less distinct, which generally terminate 
 at both ends on tendinous tissue; these bundles are composed 
 of visible fasciculi or fibres, themselves resulting from micro- 
 scopic elementary fibres. The cellular tissue and the adipose 
 tissue form for them envelopes and partitions the more dis- 
 tinct in proportion as the bundles are themselves distinct and 
 voluminous. The nerves of these muscles are very abundant, 
 especially in those of the organs of sense, and almost all come 
 from the spinal marrow; few are derived from the grand sym- 
 pathetic, and these last are never alone. 
 
 722. Besides these parts so essential to the muscles, these 
 organs have dependences: these are the fasciae (519,) or en- 
 veloping aponeuroses which surround the muscles, maintain 
 them in their place, and furnish them with partitions by which 
 they are separated, as well as points of attachment; it is also 
 the sheaths and rings that enclose the tendons and prevent 
 their being displaced, and the synovial membranes that facili- 
 tate their sliding. 
 
 723. The muscles are divided, with reference to the mo- 
 tions which they produce, into congenerous and antagonist 
 muscles, according as they concur in the same movements, or 
 produce opposite ones. The motions which take place in 
 the human body, and which are produced by the muscles, are 
 movements of flexion and of extension, of lateral inclination, 
 of rotation in two opposite directions, which in the forearm 
 is distinguished by the terms pronation and supination, of ele- 
 vation and depression, of adduction, abduction, and deduction, 
 of dilation and constriction, of protraction and retraction, &c. 
 From these motions the muscles are called flexors, extensors, 
 pronators, supinators, elevators, &c. 
 
 The antagonist muscles present some differences: in almost 
 all parts of the body, the muscles destined to effect a motion, 
 
OF THE EXTERIOR ?>P 449 
 
 are stronger than those which produce the opposite motion. 
 Those of the two sides of the body which produce the lateral 
 inclination, and the rotation round the axis of the body, pre- 
 sent only the slight difference which is generally observable 
 between the two sides of the body. The others present much 
 more important differences. Borelli thought that the flexors 
 were shorter than the extensors, and that contracting with an 
 equal force, they necessarily draw the bones in flexion. 
 Richerand also thinks that the difference is in favour of the 
 former; Meckel has adopted this opinion: these two physiolo- 
 gists are of opinion that this difference is established on the 
 observation of the bent attitude that is assumed by every part 
 of the body in a state of repose, and that its cause exists in the 
 force and length of the muscles, in the volume of their nerves, 
 and in the more favourable disposition of the flexors, relatively 
 to the centre of motion, and to the direction of the bones. 
 
 Ritter has added to these differences that the flexors contract 
 when the positive pole of the galvanic pile communicates with 
 the muscular extremity of the nerve, and the negative pole 
 with the central extremity; and that the contrary obtains with 
 the extensor muscles. This difference, doubtless, is a mere 
 difference of galvanic susceptibility ; a susceptibility sufficiently 
 powerful in the strongest muscles, to cause them to contract 
 under the least favourable circumstance of the galvanic action. 
 
 Roulin* thinks with Borelli, that the principal cause of an- 
 tagonism between the flexors and extensors depends on their 
 respective length, and consequently on their tension. 
 
 This question perhaps merits being considered in a more 
 general manner; the predominance must be sought in the 
 length and in the volume of the muscles, and more properly 
 in the number of fleshy fibres that enter into their composi- 
 tion- it must also be sought in the disposition of the muscles 
 relatively to the levers on which they act ; it is necessary to 
 observe what the attitude is that the parts take in their most 
 ordinary action, and that which they take in repose, during 
 
 * See Recherches sur fa mouvemens et ks attitudes de thomme, dans k 
 journal de physiologic, Vol. I. et II. 
 
450 GENERAL ANATOMY. 
 
 sleep, and in a state of paralyses; regard must also be had to 
 that which they take in general tonic spasm or in tetanus: 
 now, in having regard to these various considerations, it would 
 seem that the extensors are the preponderating muscles in 
 the trunk; in the jaw, the elevators; in the superior members 
 generally, the flexors; in the forearm, the pronators; in the 
 inferior members generally, the extensors; and in the feet, the 
 adductors. 
 
 724. There are in the organization several circumstances* 
 unfavourable to the action of the muscles, and which diminish 
 their power of contraction or effective force to an efficacious 
 force, i. e. to a much less considerable result. These. circum- 
 stances, well ascertained since Borelli, are, 1st, the equal divi- 
 sion of muscular effort between its two attachments, whilst one 
 point alone in general is to be moved ; 2d, the unfavourable 
 lever, that of the third kind, by which a great part of the 
 power is lost; 3d, the oblique insertion of the muscles on the 
 bones, and of the fleshy fibres on the tendons ; 4th, the resist- 
 ance of the antagonist muscles ; 5th, the friction of the ten- 
 dons and that of the articulations. 
 
 There are also in the organization, circumstances which, by 
 favouring muscular action, diminishes the influence of the 
 former: of this description are the change of the angle which 
 the muscles and the bone form, by means of certain anatomical 
 dispositions, as the volume of the articular extremities of the 
 bones, the existence of the apophyses at the place where the 
 muscles are attached, that of the sesamoid bones, &c. Such is 
 also the diminution of friction by the synovia, &c. 
 
 Finally, the animal mechanism presents the same perfection 
 as that which is every where to be admired in nature. What 
 the muscle loses in force, motion gains in extent and rapidity, 
 by the employment of the lever of the third kind, and by the 
 obliquity of insertion. On the other hand, the obliquity of the 
 muscular fibres upon the tendons, by diminishing the extent 
 of motion, and even the force of the muscle, permits, under a 
 small volume, the union of a very great number of fibres, 
 
 * J. Alph. Borelli, de motu animalium, opus posthumum. 
 
OF THE EXTERIOR MUSCLES. 451 
 
 which compensates, and much more than compensates, the loss 
 of power; without mentioning the form and freedom of the 
 limbs, which could not take place with any other insertion, 
 or any other direction of the muscles with relation to the 
 bones. 
 
 725. The muscle is the seat and the immediate organ of 
 contraction, just as the teguments and the organs of sense, 
 which form part of them, are the seat of impression. But just 
 as sensation takes place only, in so far as the impression is 
 propagated by the nerves to the nervous centre, so is it from 
 the nervous centre that volition is propagated, by the nerves, 
 to the muscle, for setting it in motion. In both cases, there 
 is, moreover, something that is entirely incomprehensible; this 
 is, the manner in which the being, the self, (moi) acquires the 
 knowledge of the sensation, and also the manner in which it 
 determines the volition. This is not the proper place for exa- 
 mining the yet unsolved question of the reciprocal action of 
 the organism and the self (moi}. 
 
 Be this as it may, the volition proceeds from the nervous 
 centre, is propagated by the nerves, and self induces the con- 
 traction of the external muscles. If the nerve be cut or inter- 
 rupted by a tight ligature, &c. the muscle, still irritable, no 
 longer contracts voluntarily. In the following chapter will 
 be seen what is the precise, or, at least, probable, seat, in the 
 nervous system, of the organic principle of the voluntary 
 motions. 
 
 726. The effects of the contraction of the exterior muscles 
 are to determine the attitudes and motions of the body, by 
 acting upon the skeleton ; to move the skin and organs of 
 sense; to produce the voice, speech, and gesture; and, lastly, 
 to subserve, in a more or less necessary, but always auxiliary, 
 manner, the vegetative functions. 
 
 727. It has already been seen that the straight muscles, in 
 contracting, draw one of their extremities, or both, nearer to 
 the centre, according as one of the points of attachment only 
 is moveable, or as they are both so; and that the circular mus- 
 cles, in contracting, narrow the orifices or canals which they 
 form. The curved muscles become straight when they con- 
 
452 GENERAL ANATOMY. 
 
 tract, if their attachments are fixed; and, in tending to bcrome 
 so, they diminish the cavities of which they form the walk: 
 as is the case with the abdominal muscles and diaphragm with 
 respect to the abdomen; and they enlarge the cavity to which 
 they correspond by their convex surface; as the diaphragm 
 does with respect to the thorax. The reflected muscles, and 
 they are very numerous, tend, like the curved muscles, to 
 become straight during their contraction; but if any insur- 
 mountable obstacle comes in the way, the motion, the direc- 
 tion of which is changed, is transmitted to the one or the other 
 extremity, or to both, according to their mobility. 
 
 728. When one of the parts to which a muscle is attached, 
 is immoveable, the other capable of being moved, it draws 
 the latter towards the former; as is the case with the muscles 
 which extend from the bones to the soft parts, &c. When one 
 of the two parts has little mobility, and the other is very mo- 
 bile, as the trunk with reference to the limbs, the central ex- 
 tremity of the limbs with reference to the peripheric extremi- 
 ty, &c. the latter is in general the only one that moves. But 
 it is to be observed, then, in this case, that the fixed point, and 
 the moveable point of the muscles may change. Thus, in 
 the most ordinary motions of the arm, the muscles which 
 move that part have their fixed point in the trunk, and their 
 moveable point in the limb. On the contrary, in the action 
 of climbing up a tree, the fixed point, at the moment when 
 the trunk rises towards the arm which was previously fixed, 
 is in the arm, and the moveable point in the trunk. So also 
 in the action of going up a ladder, when the leg is carried 
 forwards and upwards, the fixed point is in the trunk. When 
 afterwards the trunk rises towards the leg whose foot is sta- 
 tionary and firm, the fixed point is in the leg, and the move- 
 able points of the muscles are in the thigh and trunk. 
 
 When the two parts to which the muscles are attached are 
 nearly equally mobile, contraction tends to move them about 
 equally. Thus when one is lying upon a horizontal plane, 
 the contraction of the anterior muscles of the trunk tends 
 nearly equally to bend the head upon the neck, and the pelvis 
 upon the loins. 
 
OF THE EXTERIOR MUSCLES. 453 
 
 In this case and in the preceding, which are of extremely 
 frequent occurrence in the animal mechanism,* the part which 
 is to serve as a fixed point is retained by the contraction of 
 other muscles which render it motionless. The motions ap- 
 parently the most simple almost always require the simultane- 
 ous action of a greater number of other muscles than those 
 which are destined to produce them immediately. 
 
 729. It is in efforts especially that we observe these mus- 
 cular synergies. 
 
 An effort, t nisus, is any muscular action of extraordinary 
 intensity, destined to surmount an external resistance, or to 
 perform a laborious function, whether accidentally or natural- 
 ly. Thus, the action of raising or carrying a heavy body, 
 parturition, difficulty of passing the urine, &c. require efforts 
 before they can be executed. 
 
 In every effort, there is an extraordinary nervous influx 
 upon the muscles. Sometimes this influx is voluntary, some- 
 times involuntary. In the latter case, it is irresistibly deter- 
 mined by the connexion already remarked between the invo- 
 luntary internal muscles, and their external congenerous 
 muscles. In every effort, also, a great number of muscles, 
 sometimes the whole apparatus of motion is in action. Lastly, 
 in every effort, the lungs are first filled with air by an inspira- 
 tion, the glottis is closed or simply narrowed, the muscles of 
 expiration are contracted, and the walls of the thorax are thus 
 rendered immoveable, in order to present fixed points of at- 
 tachment to the muscles of the abdomen and limbs. 
 
 The effects of efforts are to retard or prevent the entrance 
 of the venous blood into the thoracic trunks, whence its re- 
 flux and its stasis in the veins of the neck, the head, the abdo- 
 men, and even the limbs; to compress the thoracic and abdo- 
 
 * Winslcnv, Mem. de PAcad. des Sc., 1719-23-26-29-30-39-40, &c. 
 
 f Js. Bourdon, Recherches sur le mt-canisme de la respiration et de la circu- 
 lation du sang. Paris, 1820. J. Cloquet, De V influence, des efforts sur les 
 organ cs renfermcs dans la cavite thorachique. Paris, 1820. Magendie, 7> 
 ^influence des mouvemens de la poitrine, et des efforts, sur la circulation du 
 sung. Journal de Physiologic, vol. i. 
 
454 GENERAL ANATOMY". 
 
 minal viscera, and even sometimes to produce their expulsion, 
 especially that of the latter, through an opening in the walls. 
 Efforts occasionally even go so far as to produce rupture of 
 the muscles, tendons or bones, and to cause ruptures of the 
 blood-vessels, hemorrhages and effusions of blood. 
 
 730. The muscles which pass over several joints may 
 move them all. Thus the flexors of the fingers, after having 
 bent the third and second phalanges on the first, bend the lat- 
 ter on the metacarpus, and the hand on the fore-arm. One of 
 the two even contributes to pronation. It is the same in the 
 foot, where the common extensor of the toes bends the foot 
 upon the leg, and where even the same disposition occurs. 
 These muscles, which pass over several joints, have also other 
 uses. They are auxiliaries or supplementary parts to shorter 
 muscles, extending only to the two bones united by an articu- 
 lation. Thus, the biceps, semi-tendinosus and semi-membra- 
 nosus of the thigh, which pass over two articulations bending 
 in opposite directions, may assist or become the substitute in 
 their functions, of the extensor muscles of the pelvis upon the 
 thigh, and of the flexors of the thigh upon the leg. The mus- 
 cles of this kind, which are so numerous in the limbs, espe- 
 cially the inferior ones, and which equally exist in the di- 
 rection of extension and in that of flexion, appear also to be 
 intended for the purpose of rendering the act of standing se- 
 cure, by applying the articular surfaces against each other, 
 and preventing motion in all directions. 
 
 731. Muscular motion is simple when it is impressed by 
 a single muscle or by several muscles which act in the same 
 direction. It is compound, when it is produced by several 
 muscles which act in different directions. Simple motion 
 commonly takes place in the direction of the muscle itself or 
 of the muscles which produce it. Thus the flexors of the fingers 
 bring them in their proper direction. In other cases, the mus- 
 cle being reflected, the direction of the motion is determined 
 by that of the portion of the muscle which extends from the 
 place where it changes its direction to the mobile part. Thus 
 the motion induced by the obliquus occuli longus, by the cir- 
 cumflexus muscle of the palate, the lateral peronsei, c., has a 
 
OF THE EXTERIOR MUSCLES. 455 
 
 direction determined by that of the last portion of these mus- 
 cles. The direction of the motion is frequently in a great 
 measure determined by that of the articulations of the bones. 
 Thus the bones articulated by ginglymus and by rotatory ar- 
 ticulation, although most of them have oblique muscles, move 
 in only two opposite directions. Thus, on the other hand, 
 the same muscle, the biceps flexor cubiti, without changing its 
 direction, produces by its contraction the supination and flex- 
 ion of the fore-arm. Thus also, the pyramidales, gemelli, &c., 
 which are rotators of the thigh outwards, when it is extended, 
 become abductors when it is bent. 
 
 732. In many cases the muscular motions are compound; 
 several muscles contracting simultaneously, communicate to a 
 moveable part a motion different from that which results from 
 the contraction of each of them in particular. Thus, if the 
 rectus superior and rectusexternus of the eye contract toge- 
 ther and with equal force, the eye obeying these different 
 forces, the pupil will be directed upwards and outwards. Thus, 
 if the pectoralis major, which carries the arm inwards and 
 forwards, contracts at the same time with the latissimusdorsi, 
 which carries it inwards and backwards, the arm will be car- 
 ried, by a compound motion, directly inwards. The motions 
 of the shoulder are always compound. Many other parts are 
 often so also; and were it not so, the motions, which are so 
 varied, would be extremely limited. 
 
 733. The motions of the voluntary muscles are in fact 
 most commonly combined. In this respect, the muscular ac- 
 tions may be distinguished into isolated motions, resulting 
 from a single muscle in contraction; into associated or com- 
 bined motions, resulting from the action of several associated 
 muscles, whether congenerous or antagonist, to produce deter- 
 minate motions, as those of flexion, extension, &c. ; into co- 
 ordinate motions, as those which by their association produce 
 standing, locomotion, &c.; lastly, actions of the will, or mus- 
 cular actions directed by volition. These variations in mus- 
 cular action depend upon the nervous influence, according as 
 it is voluntary, and according as, without the influence of the 
 
 will, it is determined by irritation of the nervous centre, by 
 5!) 
 
456 GENERAL ANATOMY. 
 
 that of the plexus of a limb, or only by that of an isolated 
 nerve. 
 
 734. The contraction of the external muscles, through 
 causes which act upon the muscular tissue, or upon the nerves, 
 or upon the nervous centre, sometimes becomes feeble and un- 
 certain (in trembling;) impossible (in paralysis;) permanent 
 (in tonic spasm or contraction, tetanus;) involuntary and irre- 
 gular (in convulsions, clonic spasm, or contraction.) 
 
OP THE NERVOUS SYSTEM. 
 
 CHAPTER X. 
 
 OF THE NERVOUS SYSTEM. 
 
 735. The Nervous System, Systema nerveum, compre- 
 hends cords (nerves,) enlargements (ganglia,) and a central 
 mass (the brain in general,) formed of a white and grayish 
 substance, which, during life, keeps up the irritability, are the 
 conductors and receptacle of the sensations, the point of de- 
 parture and the conductors of volition; in a word, the organs 
 of innervation. 
 
 The nervous centre is moreover the organ, or in other words 
 the material instrument of intellect. 
 
 736. The Asclepiades were not acquainted with either the 
 nerves or the ganglia. One may easily be convinced, on read- 
 ing the works of Hippocrates and Aristotle, that they have 
 confounded under the nameN^w, ligaments, tendons, nerves, 
 and even the vessels. Praxagoras appears to have been the 
 first who had any correct idea of difference among the white 
 organs; but having placed the origin of the nerves at the ter- 
 mination of the arteries, he gave rise to an opinion respecting 
 the hollow structure of the nerves, which has been continued 
 up to the present time. Herophilus and Erasistratus knew 
 the connexion of the nerves with the brain, but they continu- 
 ed to give the same name to the tendons and ligaments. Ga- 
 len unraveled the confusion which still prevailed in his time 
 with regard to this subject, by giving names to the ligaments 
 and tendons. By perceiving that the nerves are medullary in 
 their interior, and membranous at the exterior, he clearly de- 
 termined their connection with the spinal marrow and brain. 
 He remarked, in opposition to an opinion that had existed pre- 
 viously to him, that the spinal marrow is subordinate to the 
 
ti T : N E R A L A X A T M Y .- 
 
 brain, which is therefore the nervous centre. Me attempted 
 to establish a distinction between the nerves of feeling and 
 those of motion, and first described and named the nervous 
 ganglia. He had also made considerable progress in the know- 
 ledge of the nerves in particular. The anatomists of the Ita- 
 lian school having found neurology much in the state to which 
 Galen had brought it, greatly improved its condition. G. 
 Bartholin reproduced the opinion of Praxagoras and some 
 others of the ancients, that the spinal marrow is the centre of 
 the nervous system, and that the brain is only a continuation 
 of it. From this period, the anatomy of the nervous system, 
 whether in animals, or in the human species, has been contin- 
 ually enriched by new facts. 
 
 737. The most simple animals have no distinct nervous 
 system (28.) 
 
 The first in which it begins to make its appearance are the 
 radiated animals, and in particular the asteriaB or sea-stars, in 
 which it consists of soft threads and small enlargements dis- 
 posed around the mouth, both white and destitute of cincritious 
 matter. 
 
 In all the other invertebrate animals, the nervous system 
 consists of two more or less approximated cords, brought to- 
 gether into a greater or less number of knots or ganglia, im- 
 properly called spinal marrow in the articulata, always united 
 around the oesophagus or above the mouth by a nervous ring 
 at least, and often by a ganglion, of which the volume is pro- 
 portionate to the greater or less degree of complexity of the 
 head, and which, in the mollusca, receives the name of brain. 
 
 In all these animals, the two teguments and their muscles, 
 the organs of the vegetative functions and those of the animal 
 functions, receive similar nerves. . 
 
 However, there already occurs in the nervous ganglion of 
 the cephalopoda, (50) an evident indication of a nervous cen- 
 tre peculiar to the organs of sensation and motion. 
 
 738. In the vertebrate animals,* the nervous system con- 
 
 * See M. Tiedemann's excellent work: Anatomic und Bildungsgcschicli!< 
 des gehirns t &c. Niirnberg, 1816; translated into French by M. Jourdan: 
 Anatomic du cerveau, contenant thistoire de son dcvdoppemcnt dans lefatus, 
 
OF THE NERVOUS SYSTEM. 45.0 
 
 sisls of a central mass peculiar to that class, and composed of 
 a longitudinal cord, the spinal marrow, in which the ganglion' 
 form is no longer apparent, and whose upper or cranial extre- 
 mity, divided into the pair of cords, presents enlargements 
 and developments, which together form the encephalon. These 
 parts, viewed successively from behind forwards, are the ce- 
 rebellum, the tubercula quadrigemina, the cerebrum, properly 
 so called, and the olfactory lobes. The spinal marrow gives 
 attachment to a number of pairs of nerves corresponding to 
 that of the vertebra. Each of these nerves is furnished with 
 a ganglion near its central extremity. The cranial portion of 
 the spinal marrow (the medulla oblongata) furnishes nerves to 
 the organs of sense and the other organs of the face, and to 
 those of digestion and respiration. Moreover, there exists on 
 each side, before the vertebral column, a knotted cord (the 
 great sympathetic nerve) and nervous ganglia and cords for 
 the heart and alimentary canal, a particular nervous system, 
 which alone, or joined to the pneumo-gastric nerve, resembles 
 in its distribution the first appearances of this system in the 
 animal kingdom. 
 
 739. The spinal marrow, which is hollow in the ovipa- 
 rous animals, becomes full in the mammifera. In the former 
 it occupies the whole length of the vertebral canal; in the 
 mammifera it extends into the sacrum. Its volume is so much 
 the greater compared with that of the brain, or the latter is so 
 much the smaller compared with the spinal marrow, as we ex- 
 amine the animal series farther removed frorTi the adult man 
 to fishes. It is cylindrical, with slight bulgings at the places 
 where the nerves of the limbs are attached to it. Its cranial 
 portion also presents enlargements in proportion to the nerves 
 there inserted. 
 
 The cerebellum, which is formed by the posterior or resti- 
 form cords of the spinal marrow, expanded, reflected and 
 united above the fourth ventricle, is very simple in the osse- 
 ous fishes, in many of the cartilaginous fishes, and in the great- 
 
 avec une exposition comparative de sa structure dans les animaux. Paris, 
 1823. Desmoulins; Exposition succincte du dcvdoppcment ct dcs functions 
 du systeme cerebro-spinal. 
 
460 GENERAL ANATOMY. 
 
 er number of reptiles. In the others, and especially in birds, 
 it is more complex. In them there are already perceived la- 
 minae and the commencement of lateral hemispheres; but in 
 no oviparous animal are there yet seen the prolongations des- 
 tined to form the annular protuberance, or that protuberance 
 itself. In all the mammifera we find the lamellated structure 
 of the cerebellum, lateral hemispheres, a ciliary body in the 
 peduncles, and a protuberance. These parts are the more de- 
 veloped the higher we rise in the class of mammifera towards 
 man. The prolongations of the cerebellum at the tubercula 
 quadrigemina also exist in all the mammifera. The ventricle 
 of the cerebellum is common to the four classes of vertebrate 
 animals. 
 
 In some fishes there are observed encephalic lobes posterior 
 to the cerebellum. Such are those which correspond to the 
 origin of the nerves of the electric apparatus of the torpedo. 
 
 The corpara quadrigemina, which are formed by the de- 
 velopment of the lateral or olivary cords of the spinal marrow, 
 appear to exist in all the vertebrate animals, although there 
 has been much diversity of opinion with respect to their de- 
 termination. In all they are the principal point of origin of 
 the optic nerves. In all they form, by their union in the mid- 
 dle line, the upper wall of a cavity situated between the ven- 
 tricle of the cerebellum and the third ventricle. They are so 
 much the larger in proportion to the encephalon in general, 
 the more simple it is. They are bigeminous only in the ovi- 
 para, and are quadrigeminous only in the mammifera. The 
 anterior pair is larger than the posterior in the ruminantia, so- 
 lipeda and rodentia. The reverse takes place in the carnivo- 
 ra. The two pairs are about equal in the quadrumana and in 
 man. 
 
 The brain, properly so called, which results from the expan- 
 sion of the anterior or pyramidal cords of the spinal marrow, 
 which cross each other in all the mammifera and in the birds 
 of prey only, and not in the other animals, and are enlarged by 
 additional fibres from the optic thalami and the corpora stria- 
 ta, presents many differences in its volume and complication, 
 which are in general proportionate to the volume of these thala- 
 
OF THE NERVOUS SYSTEM. 461 
 
 mi and these corpora. The cartilaginous fishes have no brain. 
 (Desmoulins.) In the osseous fishes it is formed by the optic tha- 
 lamus alone, which is solid. (Desmoulins.) In reptiles and birds, 
 it is formed by the same body, which is hollow, and bears 
 some resemblance to the hemispheres of the mammifera; but 
 these hemispheres do not cover the tubercula quadrigemina, 
 and have as yet neither lobes, nor circumvolutions, nor corpus 
 callosum. The brain of the mammifera, which is formed by 
 a recurved medullary membrane, whose fibres come from the 
 corpora pyramidalia, optic thalami and corpora striata, gradu- 
 ally approaches to that of man, presenting various degrees 
 of organization. The rodentia and cheiroptera occupy the 
 lowest rank in this respect. Their hemispheres do not en- 
 tirely cover the tubercula. They have only a superficial fis- 
 sura sylvii, a few slight grooves, and no circumvolutions. In 
 the carnivora, the ruminantia, the hog and the horse, the he- 
 mispheres, which are much more voluminous and prominent, 
 cover a part of the cerebellum. Th'ey have circumvolutions 
 and anfractuosities, but are still destitute of posterior lobes. 
 In the quadrumana, the hemispheres cover the cerebellum, 
 but the posterior lobe is still destitute of circumvolutions. 
 
 The corpus callosum, which is formed by the reflection to- 
 wards the median line of the fibres of the peduncles spread 
 out in the hemispheres, do not exist in the ovipara. In the 
 mammifera its extent is proportionate to that of the hemi- 
 spheres. It is accordingly very small in the rodentia. 
 
 The lateral ventricles, which are formed by the replication 
 of the nervous membrane of the hemispheres, are propor- 
 tionate to the extent of the latter. 
 
 The fornix does not exist in fishes. We find the first traces 
 of its pillars in reptiles, and still more distinctly in birds. In 
 all the mammifera the pillars are united to form the fornix. 
 In them there occur, moreover, the septum lucidum and its 
 ventricle. These parts are proportionate to the extent of the 
 hemispheres. 
 
 The cornu Ammonis exists only in the brain of the mam- 
 mifera. The unciform eminence exists in none of the animals, 
 excepting perhaps the quadrumana. 
 
462 GENERAL AXATOMY. 
 
 The pituitary gland exists in all animals. It is very larirc 
 compared with the encephalon in all the inferior classes. The 
 pineal gland appears to he wanting in the class of fishes. 
 
 The olfactory lobes terminate the encephalon anteriorly. 
 According to M. Desmoulins they form what is called the 
 brain in the cartilaginous fishes. They equal the brain in size 
 in many osseous fishes and reptiles. They are very small in 
 birds, greatly developed and hollow in many mammifera, and 
 rudimentary in the human species. 
 
 The principal differences which the nervous centre presents 
 in man, are, therefore, the volume of the cerebellum and ce- 
 rebrum, compared with the spinal marrow, the tubercles and 
 the olfactory lobes; the size of the lateral lobes of the cere- 
 bellum compared with the middle lobe; that of the cerebial 
 hemispheres, and their posterior prolongation; the existence 
 of its posterior lobe and its appendages; the thickness of the 
 nervous membrane which forms the hemispheres, the size of 
 its central medullary mass, the number and depth of its sulci, 
 the number and thickness of its convolution, whence results a 
 greater extent of its surface; and, lastly, the extent of the cor- 
 pus callosum. 
 
 740. The ancients, commencing with Galen, and many 
 moderns, have regarded the nervous system as having a single 
 centre in the encephalon, and prolongations (the spinal mar- 
 row and nerves.) It has already been seen that G. Bartholin 
 transferred the nervous centre to the spinal marrow, which he 
 did from the consideration that fishes have a very large spinal 
 marrow, and a very small encephalon, and yet that these ani- 
 mals possess a great power of motion. Bichat, developing 
 some ideas that had been vaguely advanced before him, re- 
 specting the action of the ganglia, proposed two distinct nerv- 
 ous centres, the one (the cerebral, or encephalic and spinal) 
 subservient to the sensations accompanied with consciousness, 
 intellect, and voluntary motion; the other (the ganglionary) 
 subservient to the functions which are performed without con- 
 sciousness and volition. In this latter he at the same time 
 placed the seat of the passions. M. Cuvier considers the 
 nervous system as a vast net-work embracing the whole ani- 
 
OP THE NERVOUS SYSTEM. 463 
 
 mal, and furnished with numerous centres and communicating 
 cords. Dr. Gall divides the nervous system of animal life into 
 those of the spinal marrow, the organs of sense, and those of the 
 brain and cerebellum. M. de Blainville considers the nervous 
 system as divided into as many parts as there are great func- 
 tions, and defines it to be masses or ganglia and filaments, some 
 issuing forth and going into the organ which they are to ani- 
 mate, which forms the particular life; others entering, and all 
 terminating in a central mass, establishing the general life, and 
 giving rise to the sympathies and relations. The central part, 
 according to this ingenious physiologist, is the spinal marrow; 
 another part comprises the ganglia of the organs of sense and 
 motion ; a third those of the viscera, viz. the cardiac and semi- 
 lunar or coeliac ganglions ; the fourth and last comprehends the 
 great sympathetic nerve, which forms a centre to the visceral 
 ganglia, and which, by the intervention of the ganglia of sen- 
 sation and motion, connects them with the central mass. 
 
 All these divisions, which may be justified on various con- 
 siderations, are not, however, so well marked, so absolute as 
 their authors pretend. In man, the encephalon or some one 
 of its parts, the spinal marrow, where it is embraced by the 
 pons varolii, is certainly a centre to which the functions of all 
 the other parts of the nervous system are more or less subser- 
 vient. Indeed, in some of its functions, the spinal marrow 
 may be considered as a centre nearly independent; it is the 
 same with the ganglions, and finally, with the nerves; for no 
 part of the system is reduced to the entirely passive condition 
 of a conductor. This independence of the nerves, the greater 
 independence of the ganglions, and the still greater of the 
 spinal marrow, are otherwise so much the more distinctly 
 marked, as this or that function is concerned, as they are ob- 
 served in this or that animal, and as in man even they are ob- 
 served at more or less advanced periods of development. 
 These propositions, which may be regarded as the laws of 
 nervous action, will be developed hereafter. 
 
 It is sufficient now to remark that there is no absolute sepa- 
 ration between the parts of the nervous system. We shall 
 60 
 
464 GENERAL ANATOMY. 
 
 consider it successively as a whole, and in its principal parts, 
 referring the details to special neurology. 
 
 SECTION I. 
 
 OF THE NERVOUS SYSTEM IN GENERAL. 
 
 741. The nervous system* forms a continuous whole, rami- 
 fied and reticulated, all the parts of which are connected. 
 
 742. This system consists in a central mass, in nervous 
 cords, and in ganglions. 
 
 The central nervous mass, which has not received a particu- 
 lar name, and which is designated by the term of brain in 
 general, and sometimes by that of nervous axis, or cerebro- 
 spinal organ, consists of several parts which are distinguished 
 by their situation, into spinal marrow or rachiform cord 
 ('PcytM^s ^wTtos) and into encephalon (Efxt^axos); by their form 
 and texture, into nervous medulla, and into cerebrum, cere- 
 bellum, and tuberculaquadrigemina; the rudimentary olfactory 
 lobes are regarded as nerves. 
 
 The spinal marrow is a large cord single and median, di- 
 vided by a double furrow, into two lateral portions, and by 
 the insertion of the ligamenta dentata^ into anterior and poste- 
 rior fascicles. This cord contained in great part within the 
 vertebral canal, extends into the cranium, and bears there the 
 
 * Th. Willis, Cerelri anatomc nervorumque descriptio et usus, Genevse, 
 1676. R. Vieussens, Neurographiauniversalis; Lugd. 1684. G. Prochaska, 
 de structurd nervorum tract, anat.; Ejusd. Comwentatio de function, system, 
 nerv.f in op. minor. Vicq-d'azyr, liech. sur la struct, du cerveau, du ccrvelet, 
 de la moelle allongee, de la moelle c'piniere, et sur Furigine dcs nc?'fs, &c.; in 
 Mem. de 1'acad. dessc. de Paris, 1781 and 1783. A. Munro, Observ. on the 
 nervous system,' Edinb. 1783. Litdwig 1 , /Scriptorcs neurologici minores eelecti, 
 &?e.y Lipsiae, 1791-95, 4to. F. G. Gall and Spurzheim, liech. sur ksi/- 
 nerv. en general, etsur cclui de cerveait enpartioulicr,- Paris, 1809. Rolando, 
 Saggio sulla vera struttura del cevrello ddl 'uomo e degli animale, e sopra le 
 funzioni del sistema nervoso,- Sassari, 1809. Cams, Anat. und physiol, dc? 
 nervcn systems; Leipzig 1 , 1814. 
 
OF THE NERVOUS SYSTEM IN GENERAL. 465 
 
 name of medulla oblongata. In this last part, besides the an- 
 terior and posterior fascicles, there is on each side a lateral 
 fascicle. 
 
 The lateral fascicles, increased by the corpora olivaria, are 
 prolonged, for the most part, into the tubercula quadrigemina, 
 and terminate there. The posterior fascicles, after being en- 
 larged in the corpus rhomboideus, expand in the cerebellum 
 and form it; extending beyond, they unite on the one hand at 
 the median line, under the medulla oblongata, where they form 
 the annular protuberance or pons varolii, and on the other hand 
 they unite with the tubercula quadrigemina. The anterior fasci- 
 cles, after mutually crossing each other, united with a part of 
 the lateral, enlarged in the optic thalami, and the corpora 
 striata, expand in a radiated manner to form the hemispheres 
 of the brain, and unite at the median line in the corpus cal- 
 losum. 
 
 The nervous cords or the nerves, to the number of forty 
 pairs and upwards, join the medulla by one extremity; they 
 present a certain number of plexuses where they communicate 
 with each other; numerous ganglions are met with in their 
 course; [tine cords terminate by another extremity in the two 
 teguments, the organs of sense, the muscles, and in the coats 
 of the vessels, especially of the arteries. 
 
 743. The form of the nervous system is, in general, sym- 
 metrical; the symmetry is especially marked in the central 
 parts, still more so in the spinal marrow than in the encepha- 
 lon, where the surface of the lobes of the brain, and cerebellum 
 always presents irregularities. The nerves which are derived 
 immediately from the spinal marrow, are all symmetrical, ex- 
 cept the pneumo-gastric, which is distributed to asymmetrical 
 organs: all, however, in their ultimate divisions, cease to be as 
 rigorously symmetrical as in their trunks. The ganglions and 
 the nerves, which belong to the asymmetrical organs of vege- 
 tative functions, participate in their central parts,but especially 
 in their divisions and peripherical extremities, in the irregu- 
 larity of these organs. 
 
 744. The situation of the nervous system is interior and 
 central with respeet to its masses, and the nervous cords also 
 
466 GENERAL ANATOMY. 
 
 are deeply seated: the extremities alone of these cords reach 
 to the two teguments of the surfaces of the body. 
 
 745. The nervous system is formed of two substances, dis- 
 tinguished by their colour and their respective situation, into 
 white or medullary, and gray or cortical. 
 
 746. The white nervous substance, called also medullary, 
 medullaris, because that for the most part it is enveloped by 
 the other, presents several shades of white. 
 
 Its consistence varies a little in the different parts. It is in 
 general less elastic than gelatine, but a little more glutinous, 
 viscous or tenacious. The section is uniform in colour, and in 
 appearance homogeneous: red points or sanguineous striae are 
 alone perceptible in it. This substance is really very vascular; 
 when torn, the ruptured blood vessels become salient on its 
 unequal surface. 
 
 The white nervous substance, plunged for some minutes in 
 boiling oil, or for some days in alcohol, in weak nitric or mu- 
 riatic acid, in acidulated alcohol, or in a solution of corrosive 
 sublimate, augments in consistence; and if it is then attempted 
 to distend or to tear it in any direction, a fibrous appearance is 
 perceptible. White filaments as fine as hairs can be separated 
 from it. The finest fibrils that can be obtained are so delicate 
 and so closely united with each other, that it is very difficult 
 to determine any thing relative to their length and the diame- 
 ter of the finest of them, or of the primitive fibrils. These 
 fibrils, parallel or concentric, are united in fascicles which 
 have, with respect to each other, different directions. It is 
 not known with certainty whether this fibrous disposition ex- 
 ists throughout the nervous system ; it has been found wherever 
 it has been sought for, and always the same in the same parts. 
 This fibrous structure is visible in some parts of the nervous 
 system, without any preparation; almost every where more 
 difficulty is experienced in tearing this substance in one direc- 
 tion than in another, and precisely in the direction which the 
 chemical preparations show to be that of the fibres. 
 
 The white nervous substance, when dried, acquires a yel- 
 lowish colour and a corneous appearance; cut into thin slices, 
 
OF THE NERVOUS SYSTEM IN GENERAL. 467 
 
 it becomes semi-transparent, plunged into water, it takes again 
 its colour and its opacity. 
 
 747. The gray substance,* cinerea, called also cortical, 
 because it envelopes the preceding in many places, presents, 
 like it, and even still more so, varieties in shade: it varies 
 from lead gray to a blackish brown tint. This substance is 
 always softer than the white. The surface of its section is 
 uniform, and presents only points and red striae, more numer- 
 ous still than in the medullary substance. This substance, in- 
 deed, is, in some points at least, much more vascular than the 
 white. That which forms the cortical substance of the brain 
 and of the cerebellum contains so many vessels, that when it 
 has been well injected, and afterwards macerated, it appears 
 under the microscope entirely vascular. Albinus,t however, 
 affirms, and with reason, that in this case even there remains 
 one part evidently not capable of being injected, or extra-vas- 
 cular. The gray substance, submitted to the same chemical 
 preparations as the white, does not present an entirely similar 
 fibrous appearance on being torn. Submitted to the action of 
 water, the gray nervous substance becomes softer, swells a lit- 
 tle, and loses a great part of its colour. Acids, alcohol, and 
 especially corrosive sublimate, whiten it at the same time that 
 they render it harder; on being afterwards dried, it becomes 
 capable of being pulverized. The colour, a little variable ac- 
 cording to the races and individuals, appears to be a product 
 of the colouring matter of the blood. 
 
 748. The two nervous substances are differently intermin- 
 gled with each other in the different parts of the nervous sys- 
 tem: in the lobes or hemispheres of the brain and cerebellum, 
 the gray substance forms an envelope or cortex to the white; 
 in the spinal marrow, the gray substance forms two interior 
 cords, enveloped by the white substance; in the medulla ob- 
 longata and in the crura cerebriand cerebelli, masses or nuclei 
 of the gray substance are found enveloped by the white, as 
 well as alternate layers of the two substances, cords or fibres 
 of both, which cross or traverse each other reciprocally; iti 
 
 * Ludwig, de Cinerea cerebri substantia. 
 f dead, annot. lib. I. cap. 12. 
 
GENERAL ANATOMY. 
 
 the ganglions, a peculiar gray substance, traversed by white 
 fibres; finally, in the nerves white fibres alone. 
 
 The white substance alone forms a continuous whole. The 
 gray substance, on the contrary, is only met with at intervals; 
 it is found especially where the central extremities of the 
 nerves are inserted; it has been supposed even to exist at 
 their peripheral extremities, and especially in the corpus mu~ 
 cosum of the skin; it is found also where the white fibres in- 
 crease and seem to expand, as in the crura cerebri and cerebel- 
 li; finally, it is found at the surface of the brain and cerebel- 
 lum; it has been thought even, but without proof, that it ex- 
 isted in the ganglions. 
 
 The fibrous texture of the nervous substance had been for- 
 merly observed in the white substance by Malpighi, but he 
 regarded the gray substance as glandular. 
 
 This idea of Malpighi respecting the gray substance, has 
 been for a long time admitted in conjunction with the hypo- 
 thetical opinion that the nerves are hollow or canaliculated. 
 Afterwards, this idea of Malpighi, respecting the gray sub- 
 stance, gave place to that of a point of origin (Gall,) and of a 
 centre of action, (Ludwig,) &c. 
 
 749. The nervous substance, whether white or gray, on 
 being examined with the microscope,* and enlarged about 
 three hundred diameters, appears in all its parts composed of 
 semi-diaphanous globules, united by a transparent arid viscous 
 substance. These globules have appeared to Delatorre differ- 
 ent in size in the brain, cerebellum, spinal marrow, and nerves, 
 the largest being in the brain, and the smallest in the nerves; 
 these globules have appeared to him heaped together without 
 order in the central nervous mass, and in linear series in the 
 nerves; as to the liquid in which they are contained, it appear- 
 ed to him slightly viscous in the encephalon, more so in the 
 spinal marrow, and still more so in the nerves. These glo- 
 bules, and the liquid which surrounds them, furnished and re- 
 
 * J. M. Dellatorre, Nuove osserv. micros.; in Napoli, 1776. Prochaska de 
 struct, nervor. J. and Ch. Wenzell, dePenitiori struct, cerebri; Tubing 1 . 
 1812. A. Barba, Osserv. microsc. sul ccrvello e suite parti adjaccnti; Napoli 
 1807. Home and Bauec, Philos. Trans.; ann. 1821. 
 
OF THE NERVOUS SYSTEM IN GENERAL. 469 
 
 paired continually by the arrival of arterial blood, are convey- 
 ed, according to him, from the brain, as from a centre, to all 
 parts of the body, and reciprocally; their flux from the brain 
 to the muscles causes motion, their reflux from the senses to 
 the brain produces sensation. This inadmissible explanation 
 should be separated from the sufficiently exact anatomical ob- 
 servation upon which it rests. 
 
 Prochaska having examined with the microscope a laminae 
 of nervous substance sufficiently thin to be transparent, found 
 that it resembled a sort of pulp formed of innumerable glo- 
 bules or round particles; by the action of water, this pulp is 
 divided into little flocculi, and each flocculus is composed of a 
 certain number of globules; maceration, prolonged even dur- 
 ing three months, is insufficient to separate the globules from 
 each other. He concludes that the uniting medium is a deli- 
 cate cellular tissue, formed in part by sanguineous vessels, and 
 in part by prolongations of the envelope of the nervous sys- 
 tem: the globules appeared to him different in size in the same 
 part of the system; he estimates the size of those of the brain 
 and cerebellum at about one eighth part of that of the globules 
 of the blood; as to the structure of the globules themselves, 
 the most powerful microscopes teach us nothing on that sub- 
 ject. 
 
 Barba has observed the globules, and has found no difference 
 in the substance which unites them, in the different parts of 
 the nervous system. 
 
 The brothers Wenzell have added some observations to 
 these; they have found the nervous substance throughout form- 
 ed of globules which they regard as vesicles filled with medul- 
 lary or cineritious substance, according to the parts; the glo- 
 bules seem to touch each other or to adhere, and nothing is 
 perceptible between them. This globular appearance resists 
 desiccation, the action of alcohol, either pure or acidulated. 
 
 Messrs. Home and Bauer have published two different re- 
 sults of microscopic observations: according to their first re- 
 searches, the fresh brain is composed of fibres formed by the 
 reunion of globules nearly equal in size to those of pus. Ac- 
 cording to their new observations, the nervous substance is 
 
470 GENERAL ANATOMY. 
 
 composed of white, semi-transparent globules; some of thcrn 
 equal in size to those which form the nucleus of the coloured 
 particles of the blood, others smaller, of a gelatinous sub- 
 stance, transparent and soluble in water, and of a liquid simi- 
 lar to the serum of the blood: the proportion of these three 
 parts, the globules, the gelatine, and the serum, as well as the 
 size of the globules, gives rise to the principal differences 
 which the nervous system presents. The gray substance pre- 
 sents few distinct fibres not globular, it is formed especially of 
 very small globules; the gelatinous substance, and the serous 
 liquid are' very abundant in it. The medullary substance of 
 the hemispheres of the brain and cerebellum contains fibres 
 formed of linear series of globules more distinct and more 
 abundant; the greater part of the component globules are of a 
 greater diameter: the gelatinous substance is more tenacious 
 and in less proportion than in the gray substance. The cor- 
 pus callosum and the medulla oblongata have especially the glo- 
 bules of mean diameter, the gelatinous substance and the 
 serum are more abundant than in the hemispheres, and the 
 first is less tenacious. In the nerves, globules of all diameters 
 are found united into fibres, and these into fascicles. The ge- 
 latinous matter in question is found again in the blood, where 
 it serves as a uniting medium between the particles of the co- 
 louring matter which surrounds the globules. 
 
 H. M. Edwards is publishing* at the present moment mi- 
 croscopic observations, according to which the nervous sub- 
 stance of the encephalon, of the spinal marrow, and of the 
 nerves, in the four classes of vertebral animals, is composed of 
 microscopic globules, 1-300 of a millimetre in diameter, 
 united in series in such a manner as to form primitive fibres 
 of considerable length. 
 
 I have verified these observations, the importance of which 
 is so much the greater, as similar globules, but arranged a 
 little differently, are found in all the tissues of animals. 
 
 According to Carus, the nervous globules are disposed in 
 
 la structure, clcmcntairc dcs principanx tissus organiquesdes 
 animuux: These ; Paris, 30 juillct 1823. 
 
OF THE NERVOUS SYSTEM IN GENERAL. 471 
 
 clusters in the central masses which act by radiation, and in 
 regular lines in the nerves which act only as conductors. 
 
 750. The cellular tissue, which unites the nervous fibrils, 
 is soft and little apparent. This tissue is more condensed at 
 the surface; where united with the vessels, it forms a mem- 
 brane, more or less dense, more or less vascular; single for 
 the nerves (neurilema), double about the nervous centre (pia 
 mater and dura mater), having an interval with contiguous 
 walls formed by a serous membrane (tunica arachnoides). 
 
 751. The sanguineous vessels of the nervous system are 
 very numerous. They ramify very much in the immediate 
 envelope of this tissue (neurilema and pia mater); they after- 
 wards penetrate into the gray substance, where they are ex- 
 tremely abundant; they penetrate finally into the white sab- 
 stance, in which they are much finer and less numerous. No 
 lymphatic vessels have been discovered in the nervous sys- 
 tem. 
 
 752. The nervous substance has been examined chemically 
 by Thouret, Fourcroy, and Vauquelin. 
 
 The analysis of the brain by Vauquelin, has given the fol- 
 lowing results; water 80.00; white fatty matter 4.53; red- 
 dish fatty matter 0.70; albumen 7.00; osmazome 1.12; phos- 
 phorus 1.50; acids, salts and sulphur 5.15. 
 
 According to the experiments of this able chemist, the 
 spinal marrow and the nerves have the same composition as 
 the brain. 
 
 John has recognised that the gray substance contains no 
 phosphorus. 
 
 Chevreul has found in the blood a substance characteristic of 
 the nervous matter, cerebrine. 
 
 753. The vital properties of the nervous system distin- 
 guish it essentially from all other organs; besides the faculty, 
 common to all parts of living bodies, of nutrition, it possesses 
 another active property, altogether peculiar, which is called 
 nervous force, nervous power, nervous influence; manifests 
 itself by the functions of this system designated collectively 
 by the name of innervation. 
 61 
 
472 GENERAL ANATOMY. 
 
 754. Innervation* too much restricted by those who confine 
 it to sensation and volition, holds under its dependence, in a 
 more or less distinct manner, all the phenomena of life. Modern 
 physiologists in verifying this pre-eminence of the nervous sys- 
 tem, have been enabled, supporting themselves by observations 
 in comparative anatomy and physiology, by observations on the 
 development of the embryo, and by physiological and patho- 
 logical observations and experiment, to establish some laws 
 of innervation. In general, the nervous system has so much 
 the more influence upon the rest of the organization, as the 
 animal more elevated in the series has this system more de- 
 veloped. In man the nervous system has so much the more 
 influence upon the functions, as the individual is more distant 
 from the state of an embryo, and at the same time has this sys- 
 tem farther advanced towards perfection. The influence of 
 nervous action upon another function is so much the more 
 clearly marked, as this function is further removed from the 
 state of a vegetative function. The influence of the nervous 
 centre upon the rest of the system is so much greater and 
 more necessary, as the centre is more developed, more volu- 
 minous relatively to the remainder of the system, and especially 
 as the different parts of the central mass are more exactly col- 
 lected together towards a single point; it is especially in this 
 latter respect that the nervous system of man differs from that 
 of other animals. 
 
 755. The most elevated mental operations exercise them- 
 selves upon results, and manifest themselves through the me- 
 dium of nervous action; it is then true to say that man is an 
 intelligence served by organs. 
 
 Actions of combination, intermediate between sensation and 
 volition, which constitute an appearance of intelligence, or the 
 advanced instinct of vertebral animals, belong also to nervous 
 action. 
 
 * Rolando, op. cit., and Journal de physiologic, t. iii. George!, de la Phy- 
 siologic du systeme nerveux etc. Paris, 1821. Flourens, Recherches physiques 
 sur les proprietes et les fonctions du, systeme nerveux, etc.; in Archives ge- 
 ndrales de medicine, vol. ii. Fodcrc, Recher. experiment, sur le systeme 
 gerveux; in Jour, de Physiol,, torn. iii. 
 
OP THE NERVOUS SYSTEM IN GENERAL. 473 
 
 The most limited instinct, which, in all animals, even the 
 most imperfect, necessarily connect certain motions with cer- 
 tain sensations, is also a nervous action. 
 
 Sensation and volition, whatever may be the intermediate 
 phenomena, are still actions of the same kind. 
 
 The phenomena of irritation, that is to say, impression not 
 perceived and involuntary motion, are themselves more or 
 less dependent on nervous action. In the intestinal canal, in 
 the heart, &c., usually the impression is not perceived, and 
 the muscular contraction is not voluntary, but notwithstand- 
 ing the nervous system intervenes; for if in the regular order 
 the impression does not pass beyond the ganglions, and if the 
 muscular contraction is the necessary consequence, which is 
 the character of irritability, in certain cases of extraordinary 
 impressions, sensation results; also when the will is troubled 
 by the passions, the interior muscular movements are per- 
 ceived. In the vessels, and especially in the arteries, the 
 nervous action is very evident. In the cellular tissue the 
 impression and the contraction closely connected, and desig- 
 nated by the single name of tonicity, appear to be slightly 
 dependent on the nervous system, but however are not alto- 
 gether foreign to it. 
 
 The nervous influence is not limited to the organs or solid 
 parts alone, the blood* experiences its effects. 
 
 756. The nutritive and genital functions, also, are all more 
 or less dependent on nervous action. 
 
 Digestion,! not only the sensations and motions which take 
 place at the entrance of its organs, but even the action of the 
 stomach, is obedient to the nervous action; it has been known 
 for a considerable time that the section of the nerves of the 
 stomach deprives this organ of the faculty of digesting and 
 pushing forward the aliment into the intestines. 
 Respiration is not less dependent on nervous influence; the 
 
 * G. A. Treviranus, Biokgia, B. 4, page 646. Idem, Fermischte Schriften, 
 &c. B. I., page 99. 
 
 j- A. Brunn, Experim. circa ligat. nervorum. Vavasseur, de 1? influence du 
 systeme nerveux sur la digestion stomacak: These. Paris, 12. aout. 1823. 
 
474 GENERAL ANATOMY. 
 
 section of the nerves of the lungs brings on speedily asphyxia 
 and death. 
 
 The circulation, especially the action of the heart and capil- 
 lary arteries, is equally under the same influence. 
 
 Secretion is also evidently under the influence of the nerves. 
 Direct experiments show that the section of the nerves of an 
 organ, suspends its secretion. Inhalation or absorption is 
 equally modified by the nervous action. Nutrition or organic 
 formation, without being an immediate result of the nervous 
 power, notwithstanding obeys its influence. Animal heat is 
 still more evidently dependent. The physiological experi- 
 ments of Messrs. Brodie and Chossat have placed this influ- 
 ence beyond all doubt: the chemical and physiological experi- 
 ments of Messrs. Dulong and Despretz have demonstrated 
 that this heat can not depend entirely on respiration. 
 
 We see even in generation, that, the sensations and volun- 
 tary motions which accompany it, the motions of irritation, 
 the phenomena of secretion of the sperm and formation of the 
 ovules, those of the nutrition and growth of the fecundated 
 ovum, are all, but more or less directly, dependent on nervous 
 action. 
 
 757. Sympathy or the co-existence of two phenomena of 
 formation, of irritation, of sensation or of volition, in the dif- 
 ferent parts, and by the action of a single agent, the most ex- 
 traordinary fact of organization, is yet an effect of nervous 
 action. 
 
 758. What relation is there between the different parts of 
 the nervous system with respect to its functions? Is there a 
 single centre, either the spinal marrow, or the encephalon? 
 or are these two centres, viz. one cerebral and one ganglion- 
 ary ? or finally, are there as many distinct centres as there are 
 principal organs or great functions? These opinions, all found- 
 ed upon observation, are all true within certain limits. 
 
 In the adult man, the nervous system forms a single system, 
 all the parts of which concur in the action of the whole, in 
 innervation, but besides each one in its proper function. 
 Thus the brain and the cerebellum, besides their particular 
 functions, augment the energy of the spinal marrow; this last 
 
OP THE NERVOUS SYSTEM IN GENERAL. 475 
 
 augments that of the nerves. In the adult man, the encepha- 
 lon, and more precisely the mesocephalon, that is to say, the 
 cranial extremity of the spinal marrow, the place from which 
 spring the crura cerebri and cerebelli, is truly the centre of 
 the action of the nervous system. 
 
 759. What relation exists between the two substances of 
 the nervous system, and what is their particular use? 
 
 Gall regards the gray substance as the matrix of the nerves, 
 as a fertile layer in which the nerves take root, and on which 
 depends their nutrition and growth. If Gall means by this 
 that there is a true production or vegetation, he is wrong: for 
 on the one hand no part is the product of another, all are de- 
 posited by the vessels, each one in its place; and on the other 
 hand, the white substance appears before the gray, both in the 
 animal kingdom and in the embryo. If he wishes to speak 
 only of an insertion, he was right. We ought to regard with 
 Ludwig, Gall, Carus, and Tiedemann, the gray substance as a 
 centre of activity, as fortifying the action of the white parts 
 which are implanted therein, in so much especially as it pro- 
 duces this effect by the great quantity of arterial blood which 
 traverses it. This substance abounds in the spinal narrow, 
 where the largest nerves are attached; it abounds equally in 
 the corpus rhomboideum of the cerebellum, and in the optic 
 thalami and corpora striata of the brain, as well as at the sur- 
 face of these two organs in man. 
 
 760. What is the particular function of each part of the 
 nervous system ? 
 
 The nerves (sect, ii.) conduct the impressions of the sur- 
 faces to the centre, and the principle of motion from the centre 
 to the muscles and vessels. 
 
 The ganglions (sect, iii.), in consequence of the quantity of 
 blood which is distributed to them, and by that of their parti- 
 cular texture, modify the nervous action. 
 
 The central nervous mass fulfils the most important parts 
 of innervation; it is the instrument of intelligence. 
 
 The actions of combination, intermediate between sensation 
 and volition, are also functions of the encephalon. 
 
 Instinct equally intermediate between these two orders of 
 
476 GENERAL ANATOMY. 
 
 phenomena, if it is attached to a particular nervous part, has 
 probably its seat in the superior part of the spinal marrow. 
 
 It has often been attempted to determine, by observation 
 and experiment, the organic seat of sensation and volition. 
 
 Rolando regards the hemispheres of the brain as the seat of 
 these two actions, and the cerebellum as the organ which sends 
 to the muscles the motive principle under the direction of the 
 brain. 
 
 According to Flourens, the spinal marrow, at the place 
 where it is surmounted by the tubercula quadrigemina, is the 
 common point of the arrival of the sensations, and of the de- 
 parture of the nervous influence of muscular motion. The 
 cerebellum, according to this physiologist, balances the mo- 
 tions or arranges and regulates them; according to him the ab- 
 straction of the cerebellum renders the animal incapable of 
 acting in a regular and proper manner, with respect to station 
 and locomotion. 
 
 Magendie, supporting his position by the experiments of 
 Lorry, Legallois, and his own, thinks that sensibility is inhe- 
 rent in the spinal marrow. This able physiologist is of opinion 
 that the will or the faculty of determining muscular motions, 
 resides in the most elevated part of the cranial portion of the 
 spinal marrow, even in the optic thalami and the crura cere- 
 bri; that the optic thalami are necessary to lateral motions; 
 that the hemispheres of the brain are necessary for the pro- 
 duction of anterior motions, and the cerebellum for motions 
 in the opposite direction. The removal of one or the other 
 of these organs suppresses its action, and determines the irre- 
 sistible action of the other; the removal of an optic thalamus 
 determines a rotatory motion. 
 
 Foville and Pinel Grandchamps have been led by observa- 
 tions in morbid anatomy, to which they have joined experi- 
 ments on animals, to establish the seat of sensibility in the 
 cerebellum, and that of voluntary motion in the medullary 
 substance of the hemispheres; the anterior part and the cor- 
 pora striata for the abdominal members, the optic thalami and 
 the posterior part of the hemispheres for their superior mem- 
 bers. 
 
OF THE NERVOUS SYSTEM IN GENERAL. 477 
 
 Difg6s,* by ingeniously bringing together physiological and 
 pathological facts, places the seat of sensibility in the cerebel- 
 lum, and that of voluntary motion in the hemispheres of the 
 brain, admitting that the sensation is transmitted to the side 
 of the cerebellum corresponding with the impression; on the 
 contrary, as has been known for a long time, volition is trans- 
 mitted from one side of the brain to the opposite side of the 
 body. 
 
 These different opinions, contradictory in some points, rest 
 all of them upon facts more or less well observed; new facts 
 are necessary to dissipate the uncertainties which still remain 
 upon this subject. 
 
 The transmission of sensation takes place by the posterior 
 part of the spinal marrow, and that of motion by its anterior 
 part. There are, as will be seen hereafter, special nerves for 
 each of these functions. 
 
 The spinal marrow, which in these functions has only the 
 office of a conductor, is the seat or the origin of the principle 
 of irritability. If the spinal marrow of a living animal be di- 
 vided in its middle, the posterior part of the body becomes 
 insensible and immoveable. If the skin of this part of the 
 body be irritated, the irritation, though not perceived, deter- 
 mines involuntary motions in the muscles of this part. If the 
 spinal marrow be removed, and in consequence the central 
 connections of the nerves destroyed, movements of irritation 
 in the skin can be no longer excited. 
 
 The circulation is under the influence of the entire spinal 
 marrow, and of all the motory nerves which are derived from 
 it; the particular action of the heart also, but mediately, being 
 immediately under the influence of the sympathetic nerve. 
 Respiration is under the direction of the superior and lateral 
 part of the spinal marrow; digestion under the combined in- 
 fluence of the par vagum and sympathetic. 
 
 Secretion, absorption, vital heat and nutrition, are under the 
 influence of all parts of the nervous system. 
 
 761. Nothing is known respecting the manner in which 
 
 * Memoire inedit. 
 
478 GENERAL ANATOMY. 
 
 the nervous system acts. This fact escaping observation, a 
 multitude of hypotheses have been proposed, varying with the 
 prevailing doctrines at each epoch. 
 
 An attempt has been made to explain nervous action by 
 mechanical hypotheses, either by supposing that the nervous 
 fibres could vibrate in the manner of cords, or by admitting 
 such vibrations only in their elementary fibrils, or in the spi- 
 nal fibrils which have been supposed, or finally by an oscilla- 
 tion of elastic globules, the existence of which has been ima- 
 gined. 
 
 Other explanations have been founded on the supposition of 
 a nervous fluid, either material and visible, or more generally 
 an incoercible fluid; and, in this latter supposition, it has been 
 called sometimes ether, sometimes phlogistic or magnetic, lu- 
 minous, electric, latterly galvanic, according to the objects 
 which have engaged at different epochs the attention of natural 
 philosophers. 
 
 Reil has proposed on this subject an hypothesis which con- 
 sists in deriving the nervous action from a chemico-vital pro- 
 cess. He attributes in general the action of organic parts to 
 their form and composition. The form and composition of 
 organic parts being changed, their action is always so; and 
 whenever the action is changed, there are changes observable 
 in the parts; so, that as a general rule, the change of action is 
 a consequence of the change of composition in the parts: nerv- 
 ous action then supposes a change in the nervous substance. 
 What appears particularly favourable to this hypothesis of 
 Reil, is the abundance of arterial blood which is distributed 
 in the nervous system, and especially in the gray substance, 
 the volume of which is always proportionate to the nervous 
 activity (759). 
 
 762. We may, independently of every hypothesis, consider 
 the nervous action as a general fact, and observe its phenomena 
 and conditions. The phenomena of innervation are insensible 
 in the nerve, as those of muscular contraction are in the muscle: 
 nothing is visible there; however, some facts seem to indicate 
 that there occurs in the nervous substance, when in action, a mo- 
 tion of some kind, in order to produce sensation. The sensation 
 
OF THE NERVOUS SYSTEM IN GENERAL. 479 
 
 resulting from the impression made by the light upon the eye 
 is not instantaneous; the vibration or the pressure of the eye 
 in darkness gives the sensation of light, &c. Many other 
 facts collected by Darwin seem to indicate that there is in sen- 
 sation a molecular movement of the nervous substance which 
 is not instantaneous. On the other hand, many facts seem to 
 indicate that the nervous system is the forming and conducting 
 organ of an imponderable agent analogous to electricity or 
 galvanism. This nervous agent, whose existence was fore- 
 seen by Reil, recognised by Humboldt and by Aldini, ad- 
 mitted and sustained with so much talent by Cuvier, allows 
 an easy explanation of all the phenomena of nervous action, 
 and particularly the relation which exists between the benumb- 
 ing nervous action of electrical fishes and galvanic phenomena 
 on the one hand, and ordinary nervous action on the other; 
 the possibility of exciting galvanic phenomena by the nerves 
 and muscles alone; the possibility of exciting muscular con- 
 tractions, the chymifying action of the stomach, the respira- 
 tory action of the lungs, &c., by replacing nervous influence 
 with galvanic action; the existence of a nervous atmosphere, 
 acting from a distance on the nerves and muscles, and across 
 the solution of continuity of divided nerves; the wrinkling 
 which takes place in the muscular fibre in contraction, and 
 the relation of the ultimate nervous fibres, transverse with re- 
 spect to these wrinkles, is a phenomenon which approaches 
 certain electro-magnetic phenomena, &c. 
 
 These opinions have appeared so probable to Rolando, that 
 he has sought the source of the nervous agent of contraction 
 in the cerebellum, which, on account of its laminae, has ap- 
 peared to him to act in the manner of a voltaic pile, and has 
 admitted in sensation a molecular motion of the pulp. 
 
 However that may be, the nervous power is weakened and 
 exhausted by intellectual operations, by the exercise of the 
 senses, of the muscles and of the encephalon, and still more 
 by pain; it is restored by rest, food, and sleep. Its energy, 
 generally and particularly, is relative to the entire mass of the 
 nervous system and of its parts, and especially to the mass of 
 the gray substance, which is the most vascular; it is relative 
 62 
 
480 GENERAL ANATOMY. 
 
 also to the extent of surfaces. It remains sometimes after 
 death, in the nerves and muscles. 
 
 This power seems to result from the action of a subtle fluid, 
 formed by the organic action of the nervous substance bathed 
 with the arterial blood. It appears that this fluid is formed 
 throughout, but especially where there are masses of the gray 
 and vascular substance. This subtle fluid seems to traverse 
 the interior and the surface of the nerves, form an atmosphere 
 about them, and, beyond their extremities, penetrate and im- 
 pregnate all the organs and the humours themselves. The 
 blood in particular seems to be penetrated with the same fluid, 
 and to owe to it the essential properties which distinguish it 
 during Hfe. 
 
 In the mean time arterial blood furnishes the nervous sys- 
 tem with the material of its action; the arrival of arterial blood 
 is also a condition of this action. 
 
 Asphleyxia, the cause of which has been sought for in the 
 interruption of the passage of the blood through the lungs, 
 (Haller,) in the arrival of the blood, which had remained ven- 
 ous, in the left ventricle (Godwin,) in this blood penetrating 
 into the muscular substance of the heart (Bichat,) is produced 
 rather by the dark blood penetrating into the nervous substance; 
 syncope in the same manner depends on the innervation be- 
 ing cut off from the heart: life being essentially connected with 
 the reciprocal action of the blood upon the nervous substance, 
 and of the nervous substance upon the blood. 
 
 Does the nervous agent result directly and solely from the 
 reciprocal action of the blood and nervous substance? is it 
 drawn from without? can it pass from one individual to ano- 
 ther? does it result from the opposition of the white and 
 gray substances? of the action of the nervous fibre upon the 
 muscular fibre? Nervous action may then be compared to a 
 discharge of electricity. 
 
 763. Nervous action is excited or put in play by external 
 or internal stimuli. 
 
 764. The first moments of the formation and develop- 
 ment of the nervous system, can not be observed. Does this 
 system exist from the beginning, and does generation result 
 
OF THE NERVOUS SYSTEM IN GENERAL. 481 
 
 only from the uniting of the cellulo-vascular system furnished 
 by the mother, with the nervous system furnished by the male 
 (Rolando)? Does the nervous system commence with the for- 
 mation of the cardiac ganglion, and develope itself succes- 
 sively by the great sympathetic nerve and the rest of the sys- 
 tem* (Ackermann)? 
 
 What observation teaches us, is, that the nerves and the spi- 
 nal ganglions are formed before the spinal marrow, and this 
 latter before the encephalon, that is to say, before the cere- 
 bellum, the tubercles, and the brain. 
 
 The spinal marrow, at first open behind like a groove, then 
 canaliculate, by the approaching of its borders, becomes finally 
 solid. It occupies at first the whole length of the vertebral 
 canal. The white substance which forms the exterior is first 
 deposited; the gray substance being deposited afterwards in 
 the interior, fills its cavity. 
 
 The cerebellum, tubercles, and brain, which constitute at 
 first only the larger parts of the groove of the spinal marrow, 
 reverse themselves, meet, and unite at the median line, pre- 
 senting in the different places of their development, the most 
 exact resemblance with the same parts of fishes, reptiles, birds, 
 and mammalia, in ascending from the rodentia to the quad- 
 rumana [739]. 
 
 In the brain as in the rest of the encephalon, and as in the 
 spinal marrow, the increase in thickness takes place simulta- 
 neously, exteriorly, and interiorly. It is by this circumstance 
 that we must explain, with Desmoulins, the existence of a 
 cavity which is found in the foetus, within the centrum ovale 
 of Vieussens, between the interior and exterior layers of the 
 vault of the lateral ventricles. 
 
 In the encephalon as in the spinal marrow, the gray sub- 
 stance is only formed after the white, and even only after the 
 fibres of this latter are united by commissures upon the me- 
 dian line. 
 
 After birth, the increase of the nervous system, previously so 
 
 * Ackermann, de systematis ncrvei primordiis. Heidelb. 1813. Tiede- 
 mann, op. dt. 
 
482 GENERAL ANATOMY. 
 
 rapid, becomes much slower: after the internal ear and the 
 eye, it is the part of the body which then grows the most 
 slowly. 
 
 In old age, the nervous system experiences a sensible dimi- 
 nution in volume, which manifests itself in the encephalon by 
 the narrowing of the cranium,* and that can be established 
 also by measuring the spinal marrow. 
 
 765. The nervous system is also subject to many errors 
 of conformation. t One case is known of a total deprivation 
 of the nervous system: it has been observed in an acepha- 
 lous foetus reduced to a little trunk without form. There are 
 several cases of the absence of the encephalon and of the head. 
 There are a great many cases of the total absence of the nerv- 
 ous centre, the nerves and the spinal ganglions existing. 
 There are a still greater number of casesof theabsenceof the en- 
 cephalon, the spinal marrow existing, as well as all the nerves 
 of the face and neck. The spinal marrow may remain open, 
 hollow, or extended throughout the whole canal. In certain 
 cases the cerebellum and tubercles exist, as well as the crura 
 cerebri and their optic and striated enlargements, and the 
 hemispheres alone are wanting. In some cases the hemispheres 
 are incomplete ; the middle and posterior lobes are deprived 
 of furrows and convolutions. Sometimes the corpus callosum 
 only is wanting ; J or there remains a cavity within the hemi- 
 sphere, or in the septum, &c. The cerebellum may present 
 analogous defects, especially in the number of its laminae. 
 All these cases are imperfections or defects of development. 
 
 * Tenon, RecJierches sur le Crane humain, Mem, de Plnst. sc. phys. et 
 Math., tome I. 
 
 f A Beclard, Memoire sur les foetus actphales; Paris, 1815. Geoffrey 
 Saint-Hilaire, Phibs. anatom., vol. ii. Breschet, Diction, de Med., art. 
 ActpTiale, et Jlnencephale. C. P. Ollivier, d* Angers, Essaie sur Fanatomie et 
 le* vices de conformation de la moelle tpiniere,- Paris, 1823. Id. Traitt de la 
 moelle tpiniere et de ses maladies, un. vol. 8vo. Laroche, Essaie d'anat. 
 patfiol , sur les monstruosites de la face,- Paris, 1823. 
 
 |Reil, Jircliw.fur die physiologic, torn. xi. 
 
 Malacarne, Neuro encephaktomia,- Pavia, 1791. 
 
OP THE NERVOUS SYSTEM IN GENERAL. 
 
 There may exist defects of symmetry, and defects of pro- 
 portion between the different parts of the system. 
 
 766. The consistence of the nervous system is sometimes 
 changed. Softening* is an alteration very frequent in a part 
 of the central nervous mass. The softened nervous substance 
 is sometimes so much so as to be almost liquid. Its colour is 
 sometimes milk white; at other times it is yellowish, rose 
 coloured, red, or brown. This alteration is met with in the 
 optic layers, in the corpora striata, in the hemispheres of the 
 brain, in the cerebellum, in the medulla oblongata, and even 
 in the spinal marrow. It gives rise, according to its seat, to 
 different derangements of the sensations, of the voluntary mo- 
 tions, and of the other functions of the nervous system. It is 
 often the result of an inflammation ; in some cases it appears 
 independently. 
 
 The hardeningt of the nervous system has been observed by 
 Esquirol, and by S. Pinel, who has very well described it. 
 The hardened nervous tissue presents a compact mass, organic 
 in appearance ; it resembles in colour, consistence, and density, 
 the white of an egg much hardened by cooking; no blood- 
 vessels are perceptible ; it appears contracted. The hardening 
 appears to affect particularly the white substance. It has been 
 observed in the bodies of idiots, in the brain, cerebellum, and 
 spinal marrow, where it renders the fibrous disposition of the 
 white nervous substance very manifest. 
 
 767. The nervous system is subject to many affections. J 
 the principal of which are, in the central mass, sanguineous 
 congestion with or without effusion ; inflammation and its va- 
 rious degrees; the different products of chronic affections, as 
 encysted abscesses, the production of tubercles, of schirrus, 
 of cancers, of fibrous tumours and osseous, of hydatids, and 
 of foreign bodies. The membranes which envelop the cen- 
 tral nervous mass are equally the frequent seat of sudden con- 
 gestions with sanguineous or serous extravasation, of acute in- 
 
 * Rostan, Recherches sur k ramolUssement du cerveau, 2d. edition; Paris, 
 1823. 
 
 f Pinel, jr. Recherches sur fendurcissementdu syslemenerveux; Paris, 1822. 
 $ Lallemant, Recherches Jlnat. path, sur Fenctphak et ses dependences. 
 
484 GENERAL ANATOMY. 
 
 flammation in different degrees, of chronic inflammation; acute 
 and chronic hydrocephalus are also met with. The affections 
 of the nervous substance, may be complicated by those of its 
 membranes. 
 
 The affections of the spinal marrow are more rare in man 
 than those of the encephalon ; the contrary takes place in 
 animals. 
 
 These different alterations, according as they are acute or 
 chronic, according as they act by irritating, by destroying, or 
 by compressing, and according to their seat, bring on different 
 derangements more or less serious, in the functions of the nerv- 
 ous system. 
 
 768. The nervous tissue is not produced accidentally ; the 
 affinity established between this tissue and the encephaloid 
 production, by Maunoir, rests upon insufficient analogies. 
 
 The nervous tissue on being wounded cicatrizes, when the 
 wound is of such a nature as to permit the individual to sur- 
 vive. 
 
 Wounds of the encephalon, and of the spinal marrow, when 
 they are not mortal, unite like those of other parts. Wounds 
 of the encephalon, with loss of the substance of its envelopes, 
 heal by the formation of an exterior cicatrix. This fact has 
 been observed by Dumeril, in salamanders, and by many sur- 
 geons, in the human species. Wounds with loss of the sub- 
 stance of the brain, the cranium remaining entire, heal by the 
 formation of a new substance, soft, mucous like, which does 
 not altogether resemble that of the organ, and by the enlarge- 
 ment of the corresponding ventricle of the brain. Tearing of 
 the encephalon, produced by sanguineous extravasation, pre- 
 sents, when the individual survives, remarkable phenomena. 
 The blood is soon surrounded by a layer of organizable lymph; 
 this layer becomes vascular and unites with the nervous sub- 
 stance; the blood is gradually absorbed, or at first the fibrine 
 and the cruor, and then there remains the serum;* or at first 
 the serum, and then there remains a fibrinous coagulumt to 
 
 * Riobe, Observations propres a rtsoudre cette question: Vapopkxie, &c., 
 est-elle susceptibk de gueriaon? Paris, 1814. 
 f Rochoux, Recherches sur Papopkxie; Paris, 1814. 
 
ON THE NERVES IN GENERAL. 485 
 
 which the cyst unites: in the end the whole of the blood being 
 absorbed, the cyst, contracting by degrees, forms adhesions, 
 and becomes a yellowish cicatrix which perhaps finally dis- 
 appears. 
 
 The cicatrices and the other alterations of the nerves will be 
 examined hereafter. 
 
 769. The nervous system, which holds so high a station 
 in the regular exercise of the functions, fulfils one as import- 
 ant in the production of diseases:* it is that which receives and 
 which propagates the impression of morbific causes, which de- 
 termines the irregular motions of the muscles, of the heart, 
 and of the arteries, which produces morbid sympathies; and 
 as its action extends to the cellular tissue which forms the base 
 of the organs, to the blood which penetrates and bathes them, 
 one may conceive that it is foreign to no morbid action, and 
 that it is the principal agent of a great number among them. 
 
 The maladies called general, essential, or dynamic, have no 
 more probable seat than the nervous and vascular systems, the 
 centres of the animal and vegetative functions, than the blood 
 and the nervous agent which traverse them, and which are in 
 a mutual, intimate, and necessary dependance. 
 
 It is in the regular relation of these two great systems and 
 of their functions, that life and health consists; it is from the 
 the derangement of their harmony, that disease and death re- 
 sult. 
 
 SECTION II. 
 
 ON THE NERVES IN GENERAL. 
 
 770. The nerves,t nervi, are white cords formed of me- 
 dullary filaments, attached by one extremity to the nervous 
 
 * Georget, op. clt. Lob stein, Discours sur la preeminence du systeme 
 nerveux; Strasbourg", 1821. 
 
 f J. C, Reil, ExercitatiowsanatomicxdestructuranervoTuni; Halse, 1797, 
 fol. 
 
486 GENERAL ANATOMY. 
 
 centre, and by the other to the teguments, the organs of sense, 
 the muscles, and the vessels. 
 
 771. The anatomists of the Italian school were sufficient- 
 ly well acquainted with all the pairs of nerves which are known 
 at the present time; but they did not class, number, or name 
 them as is now done. 
 
 Willis gave them the numerical names and proper names 
 under which they have been generally known since his time, 
 viz. 
 
 1st. The olfactory nerves; 
 2dly. The optic or visual nerves; 
 3dly. The motory nerves of the eyes; 
 4thly. The pathetic nerves of the eyes; 
 5thly. The fifth pair; 
 6thly. The sixth pair; 
 
 7thly. The seventh pair, composed of a portio dura and 
 aportio mollis or auditory nerve; 
 
 Sthly. The eighth, or the par vagum, with its spinal or 
 accessory nerve; 
 
 9thly. The ninth pair, or the motory nerves of the tongue; 
 lOthly. The tenth pair, or the sub-occipital; 
 The nerves of the spinal marrow; 
 And the intercostal or sympathetic nerve. 
 Soemmering has modified the division of Willis. He esta- 
 blishes forty-three pairs of nerves, of which twelve pairs are 
 nerves of the brain: dividing the seventh pair of Willis into 
 seventh or facial, and into eighth or auditory; his eighth into 
 ninth or glosso-pharyngeal, into tenth or par vagum, and into 
 eleventh or accessory, the twelfth is the hypo-glossal; and re- 
 jecting the sub-occipital among the'spinal nerves, which are 
 then thirty pairs in number, the great sympathetic nerve 
 forms the forty-third pair. These modifications have been 
 generally adopted. 
 
 Bichat divided the encephalic or cranial nerves, into those 
 of the brain, those of the protuberance, and those of the me- 
 dulla oblongata. This division is not founded upon exact ob- 
 servations. 
 The nerves may be exactly divided, 1st, into nerves with 
 
ON THE NERVES IN GENERAL. 487 
 
 double roots, one arising from the anterior column and the 
 other from the posterior column of the spinal marrow; these 
 are the spinal nerves, the sub-occipital and the trigemini, or 
 the fifth pair of the cranial nerves. These nerves serve at the 
 same time for sensibility and for muscular motion. 2d, Into 
 nerves with a single root: these are the first, second, and 
 eighth* pairs, or the olfactory, optic, and auditory nerves; and 
 the third, fourth, and sixth, or the motor nerves of the eye; 
 and the twelfth or the motor nerves of the tongue. These 
 nerves serve exclusively, some for sensibility, the others for 
 muscular motion. 3d, Into respiratory nerves, vocal, and of 
 expression: they arise from the lateral fascicle of the superior 
 part of the spinal marrow; these are, according to Ch. Bell,t 
 to whom we owe an exact knowledge of them, the par vagum, 
 which is the centre of this system, the facial nerve, the glosso- 
 pharyngeal, the spinal or accessory, the diaphragmatic, and 
 the external thoracic. 4th, Into circulatory nerves: they arise 
 from all the spinal nerves; these are the great sympathetic 
 nerves. These last and the par vagum are connected besides 
 with the interior tegument, with the glands and the interior 
 muscles in general. The sympathetic nerve will be described 
 separately in the following section. 
 
 772. The form of the nerves is, in general, cylindrical. 
 Their branches are, as in the vessels, larger taken together 
 than the trunks which furnish them: the nerves consequently 
 enlarge from their origin to their termination; they also swell 
 a little at their origin. Their surface presents wrinkles or 
 transverse striae, which depend on the elongation which they 
 experience in different movements; these wrinkles are easily 
 perceived with a lens, especially in the nerves of the mem- 
 bers. 
 
 There are three things to consider in the nerves; 1st, their 
 origin; 2d, their course; 3d, their termination. 
 
 773. We must not understand by origin of nerves, the 
 
 * This must be a mistake that our illustrious author has overlooked while 
 correcting the proof; for the auditory nerve is the seventh and not the 
 eighth pair. TBAKS. 
 
 f Phil Trans. 1822, part 1 and 2. 
 63 
 
4SS GENERAL ANATOMY. 
 
 point from which they spring and upon which they vegetate, 
 if we may so express it: this origin is only the central extre- 
 mity of the nerve, or that by which it is connected with the 
 nervous centre. It is for all the nerves in the spinal marrow 
 and in the medulla oblongata; no one arises from the lobes of 
 the brain nor from the cerebellum. The olfactory nerve is 
 not even an exception to this rule; this nerve arises from a 
 prolongation of the spinal marrow, which, in animals, consti- 
 tutes the olfactory bulb. Sometimes foetuses are found de- 
 prived of the brain, and in which notwithstanding the olfac- 
 tory with the spinal marrow and the crura cerebri exist, as 1 
 have had occasion to observe lately. Bichat, in saying that 
 all the nerves arise from the medulla, makes an exception for 
 the optic and olfactory which does not really exist. 
 
 The origin of the nerves is often more deeply situated than 
 it appears at first; so that the point from which they detach 
 themselves is often not their true origin: the fifth pair, for ex- 
 ample, does not arise from the pons varolii, from which it ap- 
 pears to come, for the pons varolii does not exist among ovi- 
 parous animals, where the origin of this nerve notwithstand- 
 ing is the same as in the mammalia. We need not, however, 
 seek to pursue the origin of the nerves beyond the reach of 
 the senses, and suppose them to set out from the brain or from 
 the cerebellum, as has been done to support hypothetical ex- 
 planations. 
 
 It has been asked if the nerves cross each other at their ori- 
 gin; and it has been affirmed without hesitation that it is so, 
 to explain pathological phenomena in which the cause and the 
 effect, both seated in the nervous system, present a sort of 
 crossing. Let us see what observation teaches on this subject. 
 There is no sensible crossing in the nerves of the medulla ob- 
 longata. It is the same with those which arise from it where 
 it is prolonged into the cranium, except perhaps the optic 
 nerves, in which there appears to exist at least a partial cross- 
 ing. Authors, in effect, do not agree as to the mode of union 
 of these nerves. Their crossing, admitted by some, denied by 
 others, is evident in fishes; but in man, although in most cases 
 the atrophy of one of these nerves continues on the opposite 
 side, observers worthy of credit assure us that they have seen 
 
ON THE NERVES IN GENERAL. 489 
 
 it continue on the same side. Dissection, moreover, does not 
 show that the crossing takes place in all the fibres; so that the 
 opinion of those who think it only partial is the most proba- 
 ble. But, this exception aside, the crossing of the nerves is 
 far from being demonstrated. As much may be said of that of 
 the two sides of the brain and cerebellum, which has been ad- 
 mitted. The anterior pyramids alone present this disposition, 
 which explains how, in affections of the brain, the symptoms 
 manifest themselves on the opposite side of the spinal mar- 
 row: thus, when this last is divided beneath the place where 
 the crossing of the pyramids takes place, the symptoms appear 
 on the same side. 
 
 Another question which has been agitated among anatomists, 
 is to know if the nerves unite on the median line by commis- 
 sures analogous to those which are found between the corres- 
 ponding sides of the brain and cerebellum. This reunion is 
 evident only in the pathetic nerves. The auditory nerves are 
 also sometimes united, at their origin, by white striae, which 
 spread over the bottom of the fourth ventricle; but these striae 
 are far from being constant, and are generally wanting in youth. 
 
 Almost all the nerves have a deep origin from the gray sub- 
 stance, and not from the white, which covers this last, and 
 under which they only dip. In the spinal marrow the nerves, 
 on being torn up, leave a pit, which shows that they do not 
 stop at the surface; and when the spinal marrow is hardened, 
 the roots of the nerves may be followed and seen traversing 
 the longitudinal fibres of this organ, to implant themselves in 
 the gray substance. In the cranium this disposition is also 
 evident as respects most of the nerves. The auditory alone 
 have their origin at the surface of the medulla oblongata; but 
 there exists at the same time the gray substance in the place 
 from which they spring: only this substance is superficially 
 placed; it forms the gray band. 
 
 The nerves of the spinal marrow arise with two roots, one 
 anterior and one posterior, as has been said already. The re- 
 spective size of these two roots, upon which there have been 
 many different statements, and which Gall has said to be in 
 favour of the posterior root, is so really only in the bracJiial 
 nerves; the contrary takes place in the crural. These roots 
 
490 GENEKAL ANATOMY. 
 
 unite in theintervertebral foramen, where the posterior presents 
 a swelling or ganglion, with which the anterior is simply in 
 close contact. This last does not concur in forming this gan- 
 glion, as is said in the greater part of the treatises on anatomy, 
 although this peculiarity was pointed out long ago by Haase, 
 Munro, and Scarpa, to whom even the discovery has been at- 
 tributed. Gall only remarks, that at the neck the anterior 
 roots of the spinal nerves are soft, pulpy, and reddish; which 
 has deceived the anatomists who have examined this region. 
 In the cranium the nerves present no such distinct roots. At 
 the place where the nerves detach themselves from the me- 
 dulla oblongata, the neurilema abandons them or becomes soft- 
 ened, and confounded with the pia mater, and the medullary 
 substance alone is continuous with that of the encephalon. 
 The interior filaments of the nerve are sooner abandoned by 
 the neurilema than the exterior filaments: it follows, that where 
 the nerve is torn, it breaks farther outwards than inwards, and 
 there remains a prominence which has been erroneously com- 
 pared to an apophysis upon which the nerve is implanted. 
 
 774. In their course, the nerves branch, preserving near- 
 ly the same size in the interval of their divisions. These last 
 consist only in a separation of the component filaments, and 
 do not resemble those of vessels. The divisions of the nerves 
 are in general accompanied by those of the vessels, although 
 they do not always exactly correspond. The nerves commu- 
 nicate with each other in three different manners: 1st, by anas- 
 tomoses; 2d, by plexus; 3*d, by ganglions. 
 
 775. By anastomosis is understood the uniting of two 
 nerves. This union was thus named by the ancients, because 
 they regarded the nerves as vessels in which the nervous fluid 
 circulated, and compared them, in this respect, to arteries. 
 This expression, which has been criticized, is convenient 
 enough; for there is not, in anastomoses, a simple application 
 of the nervous filaments, but a true communication of these 
 filaments, a junction of their canal, which in truth contains a 
 substance which remains there, and not a circulating fluid, as 
 was supposed formerly. The anastomoses take place some- 
 times between the branches of the same nerve, sometimes be- 
 
ON THE NERVES IN GENERAL. 491 
 
 tween different nerves, rarely between the nerves of one side 
 and those of the opposite. 
 
 It is especially in the nervous arches that the junction of the 
 filaments is the most evident: the most remarkable of these 
 arches is that which results from the union of the par vagum/of 
 the right side and of the solar plexus, and which Wrisberg has 
 described under the name of ansa communicans memora- 
 biles. 
 
 A plexus is only multiplied anastomoses. Scarpa* has giv- 
 en a very good description of them; but he is wrong in assi- 
 milating them to the ganglions. The manner in which the 
 four last cervical pairs unite with each other, and with the 
 first dorsal, to form the brachial plexus, furnishes a remarka- 
 ble example. The cervical, lumbar, sciatic, plexuses, &c. are 
 also examples in point. These plexuses are so disposed that the 
 nerves which arise from them derive ttyeir origin at once, for 
 the greater part at least, from a certain number of the nerves 
 which constitute them. 
 
 Bichat admits that there is in plexuses something besides a 
 simple intimate mixture of the nerves. Munro says that they 
 contain gray substance, and may be considered a new origin 
 of the nerves which depart from them; but this is by no means 
 demonstrated. 
 
 The ganglions consist of tumours which contain, besides 
 the nervous filaments, a substance which is foreign to them; 
 the nervous filaments which are there mingled are much finer; 
 they present, consequently, a greater complication than the 
 two other modes of communication. They will be examined 
 after the nerves, from which they differ in several characters. 
 
 776. The termination of the nerves takes place after they 
 have traversed the anastomoses, the plexuses, or the gangli- 
 ons, or directly without their being interrupted from their ori- 
 gin. The manner of their termination is rather obscure. 
 They are seen only to be deprived of their neurilema towards 
 their latter extremity, and to become in consequence very soft; 
 so that it is then very difficult to trace them. They swell in 
 
 * Anat. annot. de gangliis etplexubus. 
 
492 GENERAL ANATOMY. 
 
 general as they approach their termination; they become flat, 
 and are then no longer visible while it appears that they should 
 still be so. There exists two hypotheses upon the final ter- 
 mination of the nerves: one is not perhaps better founded 
 than the other. According to one of these hypotheses, the 
 nerves lose themselves, so to speak, in the organs, identifying 
 themselves with their substance, which is imbibed with them, 
 if we may use the expression. According to the other, which 
 belongs to Reil, the nerve, not being capable of expanding 
 throughout every organ at once, is surrounded with a nervous 
 atmosphere in which it extends its action, nearly as is seen in 
 electric phenomena. What has led to these hypotheses, is 
 this remark, that the nerves expand into parts the extent of 
 which is much greater than their own, even after they are di- 
 vided as far as the eye, armed with a microscope, can follow 
 them, as is seen in the muscles, the skin,, the senses, and that 
 notwithstanding each point of these parts, however small it 
 may be, presents, when it is punctured, the same phenomena 
 as when the nerve itself is punctured. 
 
 The different parts do not receive an equal number of nerves. 
 The organs of sense are those which contain the most: the eye 
 and the ear, present membranous expansions entirely formed 
 of nervous substance. The skin, particularly at the hands 
 and the lips; the mucous membranes, as well on the exterior 
 as the interior; the glans and the different parts of the vulva, 
 placed at the point of junction of these membranes with the 
 skin, receive most nerves after the principal organs of the 
 senses. Then come the exterior muscles, afterwards the in- 
 terior, the blood vessels, among which the arteries receive 
 more than the veins, or the lymphatic vessels in which their 
 existence is not certain. The existence of the nerves is doubt- 
 ful in the other parts, or in those which have cellular fibre 
 for their basis, if the vessels are excepted, as the cellular tis- 
 sue, the serous and synovial membranes, the cartilages, the 
 bones, &c. : these parts, in fact, do not appear to receive nerves. 
 Finally the corneous parts and the epidermis are certainly 
 deprived of them. It is possible, on the contrary, that they 
 exist in the preceding tissues, and that their softness or their 
 
ON THE NERVES IN GENERAL. 
 
 extreme tenuity conceals them from the eye: what may in- 
 duce us to admit this, is the sensibility which these tissues 
 present in diseases. It is true that the hypothesis according 
 to which the nerves act by means of an imponderable fluid, 
 susceptible of extending its influence beyond their apparent 
 termination, may explain, to a certain point, this phenome- 
 non. According to this hypothesis, nervous action Is trans- 
 mitted beyond the nerves, and across the organic substance, 
 as nutrition takes place beyond the termination of the arteries, 
 by a sort of imbibition. 
 
 It is worthy of remark, that in some circumstances where 
 there exist paralysis of sensation, and not of motion, the in- 
 flammations which develope themselves are not accompanied 
 with pain 5 which would lead to the opinion that these same 
 cords are the seat of general sensation and of painful sensa- 
 tion, peculiar to inflammation, and that it is not solely the 
 nerves of the blood vessels which cause this last to be expe- 
 rienced. 
 
 778. The parts in which the peripheric extremities of the 
 nerves terminate in the most evident manner, are then the 
 tegumentary membranes and the senses which form a part of 
 them, the muscles and the arteries. 
 
 The senses* are organs more or less complicated, by means 
 of which external bodies are perceived; they have a structure 
 calculated to receive an impression; they are connected with 
 the nervous centre by nerves very much developed: these 
 organs are those of tact or touch, of taste, of smelling, of hear- 
 ing and of seeing. 
 
 The muscles are connected with the nervous centre by nu- 
 merous and greatly ramified nerves (662). The arteries re- 
 ceive a great number of nerves; but they are not all distributed 
 in the same manner: 1st, some only accompany them and sur- 
 round them as the ivy surrounds trees, without penetrating 
 into their tissue, unless perhaps after having accompanied 
 them for a greater or less distance: such are those which ac- 
 company the vertebral arteries, the internal carotids and the 
 
 * See Blainville, JPrincipes d'Jlnal. comparer, t. i. Paris, 1822. 
 
GENERAL ANATOMY. 
 
 facial; 2d, the others, adhering to the external membrane of 
 the artery, penetrate with it into organs which are soft and 
 pulpy: after becoming much ramified they disappear, and 
 seem to dissolve in the external membrane; 3d, finally, not- 
 withstanding the denial of Behrends, nervous ramifications 
 are seen traversing the external membrane of the arteries, and 
 terminate in the middle membrane. The nerves of the arte- 
 ries belong either to the sympathetic nerves, or to the spinal 
 and trigemini. 
 
 779. The structure of the nerves has been examined by 
 different anatomists. Delia Torre found there fibres and the 
 globules common to all the nervous system; Prochaska and 
 Reil have made better known their interior disposition. Ac- 
 cording to their researches, the nerves are composed of cords, 
 and these of very fine filaments, whose tenuity is equal to 
 the filaments of silk, and which, in the optic nerve alone are 
 equal in size to a large hair. These filaments, which are of 
 the same nature as the medullary fibres or filaments of the 
 brain and spinal marrow, differ only in being more distinct, 
 more clearly separated from each other; and in being sur- 
 rounded by an envelope or proper membrane: this envelope 
 is called neurilema, neurhymen, which signifies membrane of 
 the nerves; Galen made use of this expression, of which Reil 
 first made a precise application. The neurilema forms a ge- 
 neral envelope to the nerves, and furnishes partial envelopes 
 to the nervous cords, as well as to the component filaments: 
 it resists strongly. When it is empty, it represents an assem- 
 blage of little canals. These canals uniting together, open, 
 into each other at different distances. It is not then correct 
 to say that the nerves are composed of filaments separate 
 throughout their whole length; the communications of these 
 filaments with each other make them no longer the same: 
 examined on the superior and inferior part of the nerve, the 
 nervous cords are not simply adherent, but they send to each 
 other reciprocal filaments. The same disposition exists in 
 the plexuses, where there is an intimate communication be- 
 tween all the nerves, by means of the cords and filaments 
 they send to each other. What the plexuses present on a 
 

 ON THE NERVES IN GENERAL. 495 
 
 large scale, is seen on a small in each nerve; and the cords 
 themselves are merely plexuses of nervous filaments. Towards 
 the origin or the central extremity of the nerves, the neurile- 
 ma is continuous with the pia-mater, but only in that portion 
 of it which constitutes the general envelope of the nerve: the 
 interior sheaths of the nervous filaments become softened and 
 lost insensibly, so that these are naked in the centre of the 
 nerve. The nerves" equall} 7 are seen to become deprived of 
 their neurilema at their termination, wherever they can be 
 traced far enough. The neurilematic canals do not present in 
 the interior a smooth and polished surface as is the internal 
 surface of vessels; they give out a multitude of prolongations 
 which traverse the medulla of the nerve and sustain it: this 
 last is not free and moveable in the nerve which it owes part- 
 ly to its consistence, but which is also owing in part to this 
 disposition. There exists cellular tissue about the general 
 sheath, aad between the partial sheaths of the nerve, as has 
 been observed with respect to the muscular fascicles and the 
 fibres of which they are composed. In neuralgia, this tissue 
 Is sometimes the seat of an oedema and of an infiltration which 
 renders it, in certain cases, compact and close; at other times 
 of a sanguineous congestion or of a very great redness, as 
 Cotugno and others have observed, which leads to the opinion 
 that these painful affections depend on its inflammation. Fat 
 may also accumulate in this tissue. The medullary fibres, 
 contained in the canals of the neurilema, are of the same na- 
 ture with those of the brain and spinal marrow. 
 
 780. The blood" vessels of the nerves penetrate between 
 the cords of which they are composed, and divide, for the 
 most part, into two branches, one direct, the other retrograde. 
 Their number is considerable: all the neurilema is perceived to 
 be covered with them in .. successful injections; they are seen 
 with a lens to spread over even the neurilema of the nervous 
 filaments. This last is formed of fibrous cellular tissue and of 
 blood vessels. No lymphatic vessels of the nerves are known. 
 
 781. The structure of the nerves is not exactly the same 
 in all. In the greater part of the researches which have been 
 
 made on this subject, the optic nerve has been chosen, because 
 64 
 
496 GENERAL ANATOMY. 
 
 the nervous filaments are larger in it, and that it is easy to fill 
 the neurilematic canals. But, this nerve differs from the 
 others by its canals being separated by common partitions 
 which are detached from the interior of the general sheath. 
 The structure of the nerves has however also been observed 
 in other nerves: it is especially in those of the muscles where 
 the filaments are more distinct than in the nerves of the senses 
 or of the skin, that these observations have been made. 
 
 782. Reil, to whom we owe almost all that is known about 
 the structure of the nerves, has well indicated the means by 
 the aid of which this structure may be observed. By washing 
 the nerve with water and nitric acid, at the end of a certain 
 time, the neurilema is entirely destroyed, and there remains 
 medullary filaments which may. be seen crossing each other, 
 resting against each other, nearly like the optic nerves in their 
 commissure. On the other hand, plunging a nerve into ley, 
 which may be regarded as an alkaline solution of subcarbonate 
 of soda, the medullary substance is destroyed, and the neuri- 
 lematic sheaths are obtained. To hinder them from becoming 
 effaced, they may be filled with air: which is very easy, by 
 forcing this fluid into one of them, since they all communi- 
 cate with each other; the nerve is then tied at its two ends: 
 when dried in this state, it presents, on being cut, a multitude 
 of little canals opening into each other, which gives it the 
 aspect of the interior of a reed. These observations, which 
 have been repeated many times, after Reil, demonstrate the 
 two different substances of which the nerve is composed. 
 
 The observations of Home, upon the optic nerve, have 
 shown that the medullary filaments of which it is composed, 
 augment in number, and diminish in volume, from the origin 
 to the termination. 
 
 783. The nerves have little or no elasticity; they have no 
 sensible motion, either of oscillation, or vibration, when irri- 
 tated in the living animal. The irritation of a nerve produces 
 severe pains, and brings convulsive contractions in the muscles. 
 
 784. The functions of the nerves are to conduct sensation 
 and motion. They transmit, with incalculable velocity, voli- 
 tion from the nervous centre to the muscles, and convey to 
 
OF THE NERVES IN GENERAL. 497 
 
 the centre the sensations produced by the impression of ex- 
 ternal agents. Cutting or tying them interrupts their func- 
 tions, and renders the parts below insensible and immoveable. 
 Irritation above the interruption produces sensations of pain 
 similar to what the irritation of the extremity of the nerve 
 would have produced. Irritation below the interruption pro- 
 duces contractions, like those which result from the irritation 
 of the origin of the nerve. 
 
 785. It has been an object of research, since Herophilus 
 and Galen, whether there were not particular nerves for sen- 
 sation and others for motion. It was soon perceived that 
 there are sensorial nerves, as the first pair, the second, and the 
 auditory; motory nerves, as the third, the fourth, the sixth, the 
 hypoglossal, &c. ; and mixed nerves, as all the spinal nerves 
 which distribute themselves to the skin and muscles of the 
 trunk and members; and as the sub-occipital and trigemini. 
 But the paralyses and anestheses, which have been observed 
 sometimes united, and sometimes separate in the parts of the 
 body to which the nerves with double roots distribute them- 
 selves, led to the supposition that these nerves were composed 
 of distinct sensorial and motory filaments. The experiments 
 of Ch. Bell, those of Magendie, and my own, have clearly de- 
 monstrated that the posterior roots of the spinal nerves are 
 the sensorial, and the anterior the motory. 
 
 786. The nerves are not entirely confined to the functions of 
 simple conductors: they have an activity of their own which 
 manifests itself when they are separated from the nervous cen- 
 tre; but this activity is much augmented by that of the spinal 
 marrow, as that of the spinal marrow is by the influence of the 
 encephalon;so that the cutting off of the encephalon diminishes 
 much the activity of the spinal marrow, and that of the spinal 
 marrow lessens much that of the nerves, and the nearer to a 
 muscle a nerve is cut off, the more the nervous influence upon 
 its contraction is diminished. 
 
 787. Have the nerves a power of formation or regenera- 
 tion such, that on being cut across, their reunion shall have 
 the nervous texture and perform its functions? such even that 
 on being divided with loss of substance, they are reproduced? 
 

 GENERAL ANATOMY. 
 
 These questions have much occupied physiologists, and espe- 
 cially Fontana, Monro, Michaelis, Arnemann, Cruikshank, 
 Haighton, Meyer, &c. Most of these experimenters have re- 
 solved in the affirmative the questions relative to nervous re- 
 production. Arnemann alone, supporting himself like the 
 others upon a series of experiments, has adopted a contrary 
 opinion. 
 
 I have made, with one of my pupils/ a great number of ex- 
 periments in order to resolve these questions. There results 
 from our observations, 1st, that the division of a nerve, pro- 
 duced by a ligature, is constantly followed by the exact reunion 
 of the two ends of the nerve, and by the prompt re-establish- 
 ment of its functions; 
 
 2d. That the imperfect section or the puncture, which has 
 been accused of giving rise, in man, to so serious accidents, 
 does not produce accidents in animals, and that the reunion, 
 and the re-establishment of the functions take place very 
 promptly; 
 
 3d. That the complete section of a nerve in a part little sub- 
 ject to motion, as for example, along one of the two bones of 
 the fore-arm of a dog, in the neck of the same animal, along 
 one of the bones of the fore-arm in man, &c,,is ordinarily fol- 
 lowed promptly enough with an exact reunion, and complete 
 re-establishment of the functions ; 
 
 4th. That in parts much subject to motion, as in the vicinity 
 of an articulation, when a nerve is divided, there takes place, 
 besides the primitive retraction which is constant, an acci- 
 dental retraction and variable according to the motions of the 
 part. In this case the reunion is long in forming; it is imper- 
 fect even if it takes place: the re-establishment of the functions 
 is imperfect also, or even altogether wanting. It is to this 
 that must be referred the results of some of the experiments 
 of Meyer, and the permanent paralysis which is said to result 
 from the section of the radial nerve at the inferior part of the 
 arm; 
 
 5th. Finally, that when there is considerable loss of sub- 
 
 iiilion 
 Paris, 1822. 
 
OF THE NERVES IN GENERAL, 
 
 stance of a nerve, either by excision, or in a contused wound 
 with destruction, there remains a large interval between the 
 two ends of a nerve, and the functions are never re-established, 
 whatever may be the affected nerve ; which is sufficient to prove 
 that the anastomoses are of no avail, when the re-establishment 
 of the functions takes place. 
 
 We may then conclude that nerves divided reunite; and 
 that when the reunion does not take place, it depends only on 
 the distant separation of the extremities, brought about by the 
 motions of the parts, or by a loss of substance. 
 
 788. When a nerve has been divided, there takes place 
 during the first days, about the ends, at their surface, and in 
 their interval, an exudation of organizable matter; the sur- 
 rounding cellular tissue is penetrated by the same matter, and 
 has lost its permeability. In this state the ends of the nerve 
 are simply agglutinated together, and to the surrounding parts; 
 the functions are still suspended as they were immediately 
 after the division; the two ends of the nerve, which are swol- 
 len, especially the superior, the surrounding cellular tissue, 
 and the organizable matter, take more consistence, and become 
 very vascular. In this state, which continues some time, the 
 two ends of the nerve are united by an organized vascular sub- 
 stance; but there is still no communication, of nervous action 
 between the two ends. After a time the surrounding cellular 
 tissue ceases to be compact and vascular; the intervening sub- 
 stance, more or less long, according to the kind of wound and 
 the concomitant circumstances, diminishes by degrees in 
 volume, consistence, and redness; takes the appearance and 
 texture of nerve (a texture established by the application made 
 by Meyer of nitric acid to the nervous cicatrix) departing from 
 the extremities to the middle of their interval, and finishes by 
 fulfilling the functions, so much the sooner, and so much the 
 more exactly, as there was no interval between the ends of the 
 nerve, as in the case of ligature, or a very small one, as in the 
 case of simple section, or of a very short excision in a part 
 little subject to motion. On the contrary, when the interval 
 is considerable, the reunion does not take place, or it takes 
 place only by a cellular tissue which does not acquire, at a 
 
500 GENERAL ANATOMY. 
 
 certain distance from the extremity, the nervous properties 
 and structure. The time necessary for the complete re-es- 
 tablishment of thestructure and functions is not exactly known; 
 it has been certainly exaggerated by those who have advanced 
 that several years are required: it may be estimated at about 
 six weeks or two months. 
 
 789. The section of the pneumo-gastric and trisplanchnic 
 nerves united, as they are in the dog, produces constantly 
 death, when it is done on both sides at once. It is upon these 
 nerves that the re-establishment of the functions and the sepa- 
 ration of the tissue may be studied simultaneously, according 
 to the experiments of Cruikshank, Haighton, and our own. 
 
 The following is what we have seen take place in this sec- 
 tion, repeated at different intervals. 
 
 Having cut, on the same day, the two pneumo-gastric nrvese 
 in two different dogs, one died thirty hours after the operation, 
 the other more than sixty-six hours after this double section. 
 Another animal, after an interval of nine days between the 
 two sections, died in the night of the fourth and fifth day. In 
 a fourth, the second section having been made at the end of 
 twenty-one days, death took place only on the twenty fifth day, 
 after this second section. Finally, upon another animal, the 
 second section was made thirty-two days after the first, and 
 the animal survived an entire month. At this period, that is 
 to say, two months after the first section, we found the nerve 
 which was first divided, completely reunited. This dog fell 
 under an empyema which developed itself in the left cavity 
 of the chest. Finally, Haighton cut the second pneumo-gastric 
 nerve six weeks after the first, and the animal survived nine- 
 teen months, after which time it was killed. It has been pre- 
 tended that the nervous action, in the same manner as galvan- 
 ic action, might re-establish itself across a substance differ- 
 ent from the nervous tissue, as a fluid or moist cellular tis- 
 sue; it has been pretended, als6, that the nervous action might 
 take place at a distance, and pass over the interval which 
 exists between the ends of the nerve; it has been pretended, 
 finally, that the re-establishment of the functions might take 
 place by anastomosing branches. If it was by the one or the 
 
OP THE NERVES IN GENERAL. 501 
 
 other of these two first causes that the nervous action had been 
 continued, this action would not have been suspended a single 
 instant, and the animals would not have died in either of the 
 experiments above cited. As to the re-establishment of the 
 nervous functions by anastomoses, it is contradicted by a great 
 number of cases, in which the nerve having been cut in certain 
 subjects, and in others excised or destroyed by cautery, the 
 functions have been re-established in the first instance, and not 
 in the second. The re-establishment by anastomoses is com- 
 pletely proved false by an experiment, which consists in again 
 cutting on the same day, in the place of reunion, the pneumo- 
 gastric nerves cicatrized after previous section of these two 
 nerves at proper times. The animal, which has survived un- 
 til this moment, dies in the space of one or two days. 
 
 It is then, neither by the interposition of a substance simply 
 moist between the two ends of a divided nerve, nor by the 
 action from a distance of the nervous system, nor finally by 
 anastomoses, that the re-establishment of the nervous func- 
 tions takes place, but by a true nervous cicatrix. We see in 
 effect the functions, at first altogether destroyed, become gra- 
 dually re-established, and follow, in their re-establishment, all 
 the process of organic union. It can not be denied, however, 
 that the nervous action is propagated to a certain degree, from 
 one part to the other of a divided nerve: this is proved by the 
 experiments of Wilson Philip, which have been repeated in 
 France.* 
 
 790. The nerves are subject to other alterations besides 
 those which result from physical injuries; such are inflamma- 
 tion or neuritis, tumours or neuroma. Some consist in a sub- 
 cutaneous tubercle graniformor pisiform, hard and very pain- 
 ful; others in a schirrous tissue more or less voluminous. 
 Neuralgia and local insensibilities, paralysis and partial con- 
 vulsions, are the ordinary results of local affections of the 
 nerves; besides, these local affections extend sometimes to the 
 nervous centre, and give rise to general neuroses; 
 
 * Vavasseur dt f influence du systeme nervettx sur la digestion stomacak; 
 Paris, 1823. 
 
GENERAL ANATOMY. 
 
 SECTION III. 
 
 ON THE GANGLIONS AND SYMPATHETIC NERVE. 
 
 791. The. nervous ganglions are round or obround bodies, 
 formed of medullary nervous filaments and of a peculiar sub- 
 stance, placed upon the course of the nerv.es, and especially 
 the nerves of vegetative functions. 
 
 792. The name of ganglions, yayysuoy, was employed by 
 Hippocrates, to designate tumours of the sheaths of the ten- 
 dons. Galen first applied it to the nodosities of the nerves, 
 from comparison with morbid ganglions. J. Riolen, jr. and 
 Vieussens have made use of the same name; others have em- 
 ployed that of gangliform plexus: that of ganglion is gene- 
 rally used now. 
 
 Gall, Reil, Walter, Blainville, &c., have extended the mean- 
 ing of the word ganglion, and have applied it to the gray sub- 
 stance which exists in the interior of the spinal marrow, to the 
 masses of gray substance which are found in the medulla ob- 
 longata and in the crura cerebri and cerebelli, as the corpora 
 olivaria, the corpus rhomboideum of the cerebellum, the optic 
 thalami and the corpora striata; it has been exte.nded even to 
 the olfactory lobes, to the hemispheres of the brain, to the tu- 
 bercula and to the cerebellum; finally, the ganglions have been 
 confounded with the' plexus and with sensorial nervous expan- 
 sions. These are forced relations, which have already been 
 controverted by Walther the elder, Reimer, and Soemmering. 
 It is not in this sense that the word ganglion is employed here. 
 
 793. The ganglions have been described and studied par- 
 ticularly by Meckel,* Jonstone,t Haase,J Scarpa, Bichat,|| 
 Weber, IF and especially Watzer. ** The opinion of anato- 
 
 * Histoire de 1'acad. de Berlin, ann. 1749 & 1753. 
 
 f Essays on the use of the gang-lions, etc. 1771. Medical essays, etc. 
 1795. 
 
 % De gangliis nervnrum,- Lipsias, 1762. 
 ' De nervnrum Gangliis et plexubus,- Afutfme, 1779. 
 
 Jl Aruitornit Generate. 
 
 ^ De systemate nerveo organ.,- Lipslsp^ 1817. 
 
 ** De corporis humani Gangliorumfabricd atqueusu; Bt.rolini, 1817. 
 
ON THE GANGLIONS AND SYMPATHETIC NERVES. 503 
 
 mists and physiologists on the texture and function of gan- 
 glions, may be referred to two principal ones differently 
 modified: some, regarding them simply as condensed plexuses, 
 consider the nerves which depart from them, only as distant 
 divisions of the spinal and cranial nerves; others, considering 
 the ganglions as special nervous centres, consider the nerves 
 which emanate from them as independent of the cerebral sys- 
 tem. We shall see that these two opposite systems ought 
 to be combined and mutually modified. 
 
 794. The inferior animals, that is to say, the radiata, the 
 mollusca, and the articulata, have nervous enlargements which 
 have been assimilated to the ganglions of the vertebrata. But 
 in the invertebral animals the same nerves belong to all kinds 
 of organs and functions, whilst in the vertebrata the great 
 sympathetic nerves (and to a certain degree, the pneumo-gas- 
 tric nerves), belong especially to the organs of vegetative func- 
 tions. Weber has compared the spinal ganglions of the ver- 
 tebrata to the ganglions of the inferior animals. 
 
 In vertebral animals, which alone have true nervous gan- 
 glions comparable to those of man, we see these ganglions 
 augment, especially those of the sympathetic nerve, and the 
 pneumo-gastric nerve diminish astheencephalon becomes de- 
 veloped, so that fishes have the smallest sympathetic nerve, 
 and the largest pneumo-gastric, and vice versa in the mammalia, 
 as if the vegetative functions ought to be farther removed 
 from the influence of the encephalon, in proportion as this 
 organ is less t subject to instinct. 
 
 795. The ganglions have been divided into several kinds 
 by those who have described them with the greatest accuracy. 
 Scarpa divides them into simple or spinal, and into compound. 
 Weber divides them into auxiliary ganglions (de renforce- 
 ment,) which are those of the spinal nerves, and some of those 
 of the cranial nerves; and into ganglions of origin: these are 
 those of the sympathetic nerve, to which he joins the orbitary 
 and the maxillary. Ribes* divides the ganglions into three 
 
 * Expose sommairede quelques recherches anat. phys. et pathol., in the Mem. 
 de la soc. med. cumulation, vol. viii. 
 65 
 
504 GENERAL ANATOMY. 
 
 series: he ranges in the first the rachidian or spinal; in the 
 second those which are found in the course of the trisplanch- 
 nic; and all that are situated more internally in the third. 
 Wutzer divides them into ganglions of the cerebral system, of 
 the spinal system, and of the vegetative or sympathetic sys- 
 tem. I divide them into two kinds: list, the ganglions of the 
 encephalo-spinal nerves, some, the most numerous and the 
 most regular, belonging to the nerves with double roots, 
 others placed in the course of the nerves with a single root; 
 2d, the ganglions of the two sympathetic nerves, some form- 
 ing a double longitudinal series, and others near the median 
 line. 
 
 796. The number of ganglions is very great, as will be 
 seen. They are all situated in the trunk; Lancisi was wrong 
 in stating that they existed in the members. Their size varies 
 from that of an olive to that of a grain of millet; their form 
 is round, ova! 5 lenticular, &c. 
 
 797. The ganglions are composed of two internal sub- 
 stances: the first medullary and white; the second pulpy and 
 of a reddish gray. The medullary substance is collected into 
 cords and filaments, like the sensorial and motory nerves. 
 These interior medullary filaments are visibly the continua- 
 tion of the nerves, connected with the ganglions. The coeli- 
 ac ganglion is the only one where this continuation is not 
 clearly manifest. These filaments are recognized by their co- 
 lour and form. The action of alkalies and acids, upon them, 
 renders them manifest, even in the midst of the ganglions, as 
 nervous medullary filaments. 
 
 These filaments, on penetrating the ganglions, become de- 
 prived of their neurilema, which unites intimately with the 
 exterior membrane of the ganglion. These filaments have 
 their surface less exactly defined than in the nerves; their sur- 
 face appears more loose, as if blended or intimately united 
 with the adjacent substance. These medullary filaments have 
 otherwise considerable tenacity. 
 
 79S. The second substance of the ganglions establishes 
 not only the difference between the nerves and ganglions, but 
 between the ganglions and the plexuses. This substance has 
 
ON THE GANGLIONS AND SYMPATHETIC NERVES. 505 
 
 been much neglected by anatomists, who, considering the gan- 
 glions as plexuses more condensed, have regarded it only as 
 destined to separate or to unite the nervous filaments (Scarpa), 
 or to perform the functions of the cellular tissue (Haase). 
 The matter which surrounds the medullary filaments of the 
 ganglions is a particular cellular tissue, the interstices of which 
 are filled with a mucilaginous or gelatinous pulp, of a reddish 
 ash colour, yellowish in some ganglions. This colour, like 
 that of other organs, does not depend solely on the quantity 
 of blood which they receive. 
 
 This secondary substance is not equally abundant, and is not 
 altogether united to the medullary substance in the same man- 
 ner in all the ganglions. 
 
 799. Scarpa says that this pulpy matter is fatty in very fat 
 subjects. Meckel appears to be of the same opinion. Bichat 
 thinks, on the contrary, that the ganglions are never trans- 
 formed into fat. The observations of Wutzer, and my own, 
 are entirely in union with those of Bichat. In very fat sub- 
 jects, there accumulates, under the 'membrane of the gangli- 
 ons, fat, which, when in great quantity, surrounds not only 
 the ganglion, but compresses it and diminishes its size; not- 
 withstanding it is itself never changed into fat. 
 
 800. The ganglions are enveloped by a cellular or fibrous 
 membrane, which differs in the different kinds of ganglions. 
 
 801. The blood-vessels of the ganglions are very numer- 
 ous. The arteries come from the neighbouring trunks; they 
 ramify first in the membrane, where they form a net-work; 
 delicate branches penetrate into the filamentous and pulpy 
 tissue of the ganglion; sometimes arterial branches penetrate 
 into the ganglion with the nervous filaments, and accompany 
 them. The veins offer a similar distribution. Nothing is 
 known concerning the tymphatic vessels of these organs. 
 
 802. The medullary filaments present no interruption in 
 the ganglions; they establish a continuity or an uninterrupted 
 connexion between the nervous cords, in the course of which 
 the ganglions are placed. These medullary filaments form 
 connexions in the interior of the ganglion, and traverse them 
 in different directions, in such a manner as to unite together all 
 
506 GENERAL ANATOMY. 
 
 the cords which belong to them. From this results the irre- 
 gular figure and the interior complication of the lateral and 
 median sympathetic ganglions, which are placed in the middle 
 of many nervous cords, and the regular ovoid form, as well 
 as the simply longitudinal direction of the filaments of the 
 spinal ganglions. 
 
 803. Bichat tried some chemical experiments on the gan- 
 glions, which proved that there was nothing common between 
 their substance and that of the brain. Some anatomists, how- 
 ever, having continued to confound with the ganglions the 
 enlargements of the central nervous mass, composed of white 
 substance and of gray, Wutzer commenced a series of compa- 
 rative chemical experiments upon the ganglions, and upon the 
 intermixture of the white and gray substances of the brain 
 and cerebellum. It follows from these experiments, that there 
 is a real difference between these two objects; that the gan- 
 glions differ from the nerves by a greater proportion of gela- 
 tine, and still more from the encephalon by the excess of ge- 
 latine, by a greater quantity of albumen, and by a less pro- 
 portion of fat. Lassaigne* has made a chemical analysis of 
 the guttural ganglions of the horse, and has found them com- 
 posed, 1st, of fibrine, for the greater part; 2d, of concrete al- 
 bumen in small quantity; 3d, of soluble albumen; 4th, of tra- 
 ces of fatty matter; 5th, of phosphate and carbonate of lime. 
 Lobstein has observed that although they resist putrefaction 
 longer than the nerves, they become converted promptly into 
 fat by immersion in water. 
 
 804. The ganglions of the first sort are those which are 
 found in the course and at a small distance from the origin of 
 the nerves of the spinal marrow. There are thirty of them, 
 on each side, which are named spinal; one upon the trigemini 
 nerve, which is called Gasser's ganglion; one or two upon the 
 par vagum, and one upon the glosso-pharyngeal. The spinal 
 ganglions, first observed by Volcher Goiter, to the number of 
 thirty on each side, have an ovoid or olive form. They be- 
 long to the posterior root alone of the spinal nerves, the ante- 
 
 * Lassaigne, in the Journal de Physiologic, vol. i. 
 
ON THE GANGLIONS AND SYMPATHETIC NERVES. 507 
 
 rior is united to the ganglion only by loose cellular tissue. 
 Haase first made this observation, which has since been con- 
 firmed by Prochaska and Scarpa. The anatomists who pre- 
 ceded them thought that the two roots of the nerve concurred 
 in the formation of the ganglion. 
 
 The membrane of the spinal ganglions, furnished by the 
 dura mater, appears more firm, more dense, and more solid 
 than that of the other ganglions. The ganglion itself is so 
 closely enveloped, that it appears very hard. The pulpy sub- 
 stance envelopes the medullary filaments more loosely than in 
 the others, and is more distinct and more easily separable. 
 
 The medullary fasciculi having entered by the posterior or 
 internal extremity of the ganglion, divide into three, four, or 
 five white filaments. They diverge at first from each other, 
 then converge towards the other extremity. These filaments 
 unite with each other, so that each departing cord is formed of 
 filaments which probably come from several entering cords. 
 However, the number, the tenuity, and the confusion of the 
 filaments are not very great. The spinal ganglions have a sim- 
 ple texture compared with the others. 
 
 The nervous fasciculi, collected together after leaving the 
 ganglion, unite intimately, at the distance of hardly two lines, 
 with those of the anterior root, to form the common trunk of 
 the spinal nerves: a trunk which itself has only a length of 
 one or two lines before dividing into the anterior and posterior 
 branches. 
 
 The common trunk of each spinal nerve, at a little distance 
 from the ganglion, furnishes a simple branch, often double, 
 rarely triple, which goes towards the ganglion near the sym- 
 pathetic nervous trunk, and joins it in such a manner as to 
 establish the most intimate connexion between the nerves of 
 the spinal marrow, the spinal marrow itself, and the great 
 sympathetic nerve. Anatomists, and especially physiologists, 
 have frequently discussed the question, whether the branch of 
 communication comes from this or the other root. I have 
 seen, as well as Scarpa and Wutzer, that the simple or double 
 branch comes from the common inextricable trunk, and that, 
 when it can be traced, it is found to come from both roots. 
 
508 GENERAL ANATOMY. 
 
 This communicating branch, similar at its origin, to the spinal 
 nerves, having arrived at about a line from the ganglions of 
 the sympathetic nerve, reddens and takes successively the 
 characters of this nerve. 
 
 The ganglion of the fifth pair of nerves, or Gasser's gan- 
 glion, belongs evidently to the series of spinal ganglions, from 
 which it differs only in form. The white nervous fasciculi 
 which pass beneath, without forming a part of it, that Paletta 
 proposed to consider as particular nerves, resemble entirely 
 the anterior root of the spinal nerves. 
 
 The ganglions of the par vagum and of the glosso-phargu- 
 geal nerve resemble as yet, in their form and texture, the 
 spinal ganglions. 
 
 The trunk even of the par vagum has a texture altogether 
 peculiar and different from the other nerves, without resulting 
 however from a linear series of ganglions, as Reil says. It 
 greatly resembles the trunk of the sympathetic nerve. 
 
 805. The second sort of ganglions comprehends the series 
 of three cervical ganglions, of twelve thoracic, of five lumbar, 
 and of four sacral, belonging on each side to the trunk of the 
 sympathetic nerve. The opthalmic ganglions, spheno-pala- 
 tine, and maxillary, are also of the same sort. The cardiac 
 ganglion, often replaced by a plexus, must be joined with 
 them, as well as the semi-lunar or cceliac ganglions, and many 
 others placed in the solar plexus and its divisions; the little 
 coccygeal ganglion, which is found sometimes at the union of 
 the two sympathetic nerves, opposite the summit of the sa- 
 crum; and the little palatine ganglion, which exists sometimes 
 in the anterior palatine foramen; finally some variable gan- 
 glions are also added, which are sometimes found upon the 
 coats of the arteries, where they replace the plexuses, as the 
 ganglion of the anterior communicating artery of the brain, 
 that of the cavernous sinus, that of the deep seated temporal 
 artery, &c. 
 
 All these ganglions have in general an irregular and variable 
 figure; they have in general connexions with several nervous 
 trunks or branches. The direction of the medullary filaments 
 which traverse them is very complicated, and rarely thin fila- 
 
ON THE GANGLIONS AND SYMPATHETIC NERVES. 509 
 
 ments traverse them simply from one side to the other. The 
 pulpy substance of these ganglions is so Strongly united with 
 the medullary filaments, that it is very difficult to separate 
 them. This substance, besides, appears to differ from that of 
 the other ganglions: it is harder, more close, and more tena- 
 cious. This is especially remarkable in the cceliac ganglions 
 and in those of their plexuses. The membrane of the gan- 
 glions of this series is cellular and firm, but has not the fibrous 
 solidity of that of the spinal ganglions. 
 
 806. The cords and the nervous branches, in a word, the 
 nerves which unite these ganglions, greatly differ from those 
 which are immediately derived from the spinal narrow. In- 
 stead of diminishing like these last, in proportion as they de- 
 part from their origin, or from their central extremity they 
 furnish successive divisions, we see them indifferently dimi- 
 nish or increase, or not change their size in departing from 
 the ganglions. The ganglionary nerves have less power of 
 cohesion and more fragility than the others. The external 
 envelope of the ganglions continues upon the nerves to a cer- 
 tain distance; beyond the point where this communication 
 ceases to be apparent, the neurilema appears thinner and more 
 intimately united with the medullary substance than in the 
 other nerves. Their internal substance results, like that of 
 the ganglions, from medullary filaments, and pulpy, gray and 
 reddish substance, that can be hardly separated from them; the 
 filaments, or the branches united to form a cord, are them- 
 selves hardly separable; the ganglionary nerves, finally, seem 
 to be formed of the same substances as the ganglions, these 
 being only elongated into cords. However, the nerves of 
 the ganglions are not all absolutely similar: those which unite 
 the spinal ganglions to those of the sympathetic nerve, and 
 the splanchnic nerves, which go from the thoracic ganglions 
 of the sympathetic to the coeliac ganglions, seem intermediate, 
 by their white colour, their cylindrical form, their fibrous 
 composition, their firmness and tenacity, between the nerves 
 of the spinal marrow and the reddish gray, flattened, irregu- 
 lar, pulpy ; soft and fragile nerves of the sympathetic. Scarpa 
 pretends that the sympathetic nerves may be anatyzed by 
 anatomy, aud reduced into filaments like the others. I think 
 
510 GENERAL ANATOMY. 
 
 that this is impossible, especially in the nerves which form 
 the mesenteric or intestinal plexuses. 
 
 807. The, sympathetic nerve,* intercostal or trisplanch- 
 nic, is a nervous and ganglionary cord, extended from the 
 head to the pelvis, connected, by anastomosing branches or 
 roots, with all the spinal nerves and the trigemini, and fur- 
 nishing numerous branches to the organs of the splanchnic 
 cavities of the trunk. 
 
 The cephalic extremity of this nerve penetrates into the 
 cranium by the carotid canal and the cavernous sinus, where 
 it forms a plexus and often a ganglion upon the carotid artery; 
 it sends hence anastomosing filaments to the nerve of the sixth 
 pair, and communicates with 'the inferior filament of the vi- 
 dian; it sends secondary plexuses upon the branches of the in- 
 ternal carotid artery, and may be traced to a little solitary 
 ganglion placed upon the anterior communicating artery of 
 the brain. 
 
 It consists then of three cervical ganglions, twelve thoracic, 
 five lumbar and four sacral, and of their cords of communica- 
 tion placed on each side of the anterior face of the vertebral 
 column. 
 
 Throughout the whole length of the nerve, each ganglion 
 presents external anastomosing filaments or roots, and internal 
 filaments or branches. 
 
 In this respect, the sympathetic nerve may be compared to 
 a subterraneous stem, or an articulated rhizoma, which, at 
 each joint,presents on one side roots, and on the other branches, 
 both of which depart at right angles, or at least at a very large 
 angle. 
 
 The branches of the great sympathetic distribute themselves 
 to the organs situated in the face, neck, breast, the abdomen 
 properly so called, and in the pelvis. 
 
 The pelvic extremity of the sympathetic nerve consists of a 
 
 * Walter, tabulae, nervorum thorocis ct obdominis. Berol. 1783. H. A. 
 Wrisberg, de nervis arterios venasque comitantilus. De Nervis pharyngeis. 
 J)c Ganglio pkxuque similunari. Jh Nervis viscerum abdominalium, etc., 
 in Comment. Getting. Chaussier, Table synoptique du nerf trispktnchnique. 
 Lobstein, De ncrvi sympathetid humani fabrica, usu et morbis. Paris., 
 1823-4, cum tabulis. 
 
ON THE GANGLIONS AND SYMPATHTIC NERVE. 511 
 
 little ganglion or arch, in which the two nerves unite, and 
 which furnish some delicate filaments to the environs of the 
 anus. 
 
 The internal branches of the sympathetic nerve are distri- 
 buted, some directly upon the arteries, and form plexuses, the 
 others, in much greater number, reach the median line, and 
 form there, in uniting to those of the opposite side, median 
 plexuses or ganglions (the cardiac and creliac), which commu- 
 nicate with the branches of the pneumo-gastric nerve, which 
 furnish secondary plexuses or ganglions, and terminate in the 
 heart, the aorta, the digestive canal, the urinary and genital 
 organs, but especially in the arteries of these organs. 
 
 808. Rare interruptions, -and perhaps not well observed, 
 in the trunk of the sympathetic nerve, have induced some 
 anatomists to regard- the existence of this trunk as a circum- 
 stance of little importance. There is exaggeration in this 
 opinion. However, its roots are very certainly in the spinal 
 nerves, and not in the vidian nerve and the sixth pair. 
 
 The branches of the sympathetic nerve, differ not only from 
 tfiose of the other nerves, but they differ very much from each 
 other: each ganglion and especially each plexus of branches 
 has its proper or peculiar character. 
 
 The sympathetic nerve has been considered, by Scemmer- 
 ing especially, as the nerve of the arteries: in truth the arteries 
 receive many branches from it; but the muscular tissue of the 
 heart, that of the digestive canal, the mucous membrane of this 
 canal and the .urinary and genital passages, the ligaments, the 
 bones even of the vertebral column, receive filaments from it. 
 It is remarkable that the veins, the lymphatic vessels and 
 glands are deprived of them, as well as the serous membranes. 
 They are found, on the contrary, in the long muscles of the 
 neck, in the intercostals, and the diaphragm. 
 
 809, The spinal ganglions with their nerves, are the first 
 parts of the nervous system that are visible. 
 
 The ganglions and the nervous trunk of the trisplanchnic 
 are apparent in the foetus after the third month. The coeiiac 
 ganglions and the splanchnic nerves, which are in a manner 
 
 their roots, develope themselves a little less quickly than the 
 66 
 
512 GENERAL ANATOMY. 
 
 cervical ganglions and the cardiac nerves. In old age the gan- 
 glions are paler and drier than in the adult age. 
 
 The ganglions and cords of the sympathetic nerves are found 
 in foetuses deprived of brain, and in those which are deprived 
 of brain and spinal marrow. 
 
 810. The vertebrate* animals alone have a particular nerv- 
 ous system for the organs of vegetative functions. 
 
 In fishes the sympathetic nerve consists of a very fine 
 thread, with few or no ganglions. 
 
 In reptiles it is more distinct: it unites together the inter- 
 vertebral nerves, and penetrates into the cranium united with 
 the par vagum. 
 
 In birds it penetrates into the cranium with the par vagum 
 and the glosso-pharyngeal ; it communicates with the fifth and 
 sixth pairs; it presents in the neck an apparent interruption, 
 arising from its being contained in the .vertebral canal: it is 
 very distinct and.ganglionary in the thorax, and is prolonged 
 even unto- the caudal vertebrae. 
 
 in the mammalia the sympathetic nerve does not differ much 
 from that of man. 
 
 Meckel and Weber have remarked that the sympathetic 
 nerve is so much the smaller, relative to the body, as the -ani- 
 mal is farther removed from man. A second general observa- 
 tion is that the sympathetic nerve and the par vagum are in an 
 inverse relation with respect to their development; so that 
 they mutually supply the place of each other, in the vegeta- 
 tive life to which they both belong. It is nepessary also to 
 remark, that the sympathetic nerve is developed in all animals 
 in proportion to their circulatory apparatus, to which it in 
 great part belongs. 
 
 812. The ganglionary nervous system, which exists in all 
 animals, which, in the vertebrata, forms a system apart, in 
 connexion with the nervous centre whose development it pre- 
 cedes^ which preserves on one part the stale of dissemination 
 that the nervous system of the invertebrata presents, and 
 which forms also some principal centres, as the cardiac plexus, 
 
 * Weber, Jinatomia compar. nervi sympath.; Lips., 1817. 
 
ON THE GANGLIONS AND SYMPATHETIC NERVE. 513 
 
 and especially the ganglions, and the creliac or solar plexus, 
 which has been called the abdominal or epigastric brain, should 
 have a great importance in the organization. But before ex- 
 plaining the functions of the sympathetic nerve, it is necessary 
 to examine tfcat of the ganglions. 
 
 813. Willis had, with respect to the ganglions and sympa- 
 thetic nerve, an idea similar enough to that which now 
 prevails: he considered the ganglions as the diverticula of the 
 spirits, and the sympathetic. nerve as placed between the cere- 
 bral conceptions and the precordial affections, between the ac- 
 tions and the passions, in such a manner as to establish a con- 
 sent between the parts. 
 
 Vieussens considers also the intercostal nerve as a sympa- 
 thetic medium between the brain and the viscera of the two 
 other cavities; he places in the ganglions, which he calls 
 plexuses, a centre of muscular and fermentative action. Lan- 
 cisi also regarded the ganglions as centres of impulse which he 
 compared to the heart. 
 
 . Winslow, who first employed the name of sympathetic 
 nerve, regarded the ganglions as centres of origin, true little 
 brains. 
 
 Meckel attributed to the ganglions the use, 1st, of dividing 
 the nervous branches into lesser ramifications, and these into 
 ents; 2d, of making the branches depart in different di- 
 rections to distant places; 3d, of uniting several branches into 
 a single cord. 
 
 Zinn holds the same opinipn, adding that the branches from 
 different points uniting in a ganglion, are more intimately 
 mixed than in a plexus. 
 
 Johnstone regarded the ganglions as brains capable of de- 
 veloping and communicating the nervous power, as the origin 
 of the involuntary nerves, and as- proper to break the influence 
 of the will upon the organs of involuntary motion, such as the 
 heart. 
 
 Haase, who has assimilated the ganglions to the plexus, has 
 controverted the opinion of Johnstone with these two argu- 
 ments: that the voluntary muscles receive nerves from the spi- 
 
514 GENERAL ANATOMY. 
 
 nal ganglions, and that the involuntary organs, as the stomach, 
 receive them from the par%a'gum. 
 
 Scarpa adopts an opinion similar to that of Meckel and 
 Zinn: according to him the use of the ganglions is to mix 
 and to unite anew the nervous filaments; according to him the 
 nerves of the viscera emanate directly from the spinal nerves, 
 and from the fifth and sixth pairs, and are only collected to- 
 gether in the ganglions. 
 
 All these opinions, as we see, may be referred to two. 
 Some as Meckel, Zinn, Haase, Scarpa, and more recently, 
 Legallois, have seen in the ganglions, only a particular ar- 
 rangement, an anatomical disposition of the nervous filaments; 
 the others, as Winslow, Johnstone, Lecat, Petit, Metzger, 
 &c., have regarded the ganglions as points of origin, and es- 
 pecially as centres of nervous action. No one has defended 
 this last idea with more warmth and talent than Bichat. Reil, 
 Autenreith, Wutzer, Broussais, and many others, have added 
 new arguments to those of our celebrated author, whose opin- 
 ion they have nearly embraced. 
 
 814. Bichat regards the organic nervous system as result- 
 , ing essentially from numerous centres or from ganglions united 
 together by filaments, and the sympathetic nervous trunk it- 
 self as a series of ganglions and anastomosing filaments. Bi- 
 chat has perhaps given to ganglions an exaggerated import^ 
 ance; but certainly he has not granted to their ensemble, their 
 reunion, all the importance which it merits. 
 
 According to Reil, the sympathetic nerve constitutes a pe- 
 culiar system, which he calls ganglionary system; he calls it 
 also the vegetative nervous system. In the vertebrate animals 
 it is united to the cerebral or animal system, but if does not 
 emanate from it. This system, instead of having a single cen- 
 tre where the roots are implanted, has several -foci of action: 
 1st. It consists of plexuses or net work placed around the arte- 
 ries, about twelve in number; among them, a principal one, 
 the epigastric, furnished with ganglions, and forming second- 
 ary plexuses, is a sort of centre or brain. 2d. These plexuses 
 are connected with the cerebro-spinal system by branches and 
 conducting plexuses; the two trunks united below, before the 
 
ON THE GANGLIONS AND SYMPATHETIC NERVE. 515 
 
 coccix, and above by the fifth and sixth pairs and by the brain, 
 constitute an elliptic periphery which embraces all the system 
 of ganglions and plexuses, and into which several cerebral 
 nerves penetrate, particularly the eight pair. 3d. The branch- 
 es or conducting plexuses would transmit sensation and voli- 
 tion, if they were perfect conductors; but they -may be consid- 
 ered as semi-conductors, and theganglio'ns as isolating bodies. 
 
 There results from this two nervous systems and two spheres 
 of nervous activity: 1st, the animal sphere, in which the im- 
 pressions are perceived, where the volitions determine motion; 
 2d, the vegetative sphere, where the nervous activity is distri- 
 buted slowly, continually, and obscurely. In this system, the 
 impressions determine motion, without being propagated to 
 the animal centre. In the state of disease, however, the com- 
 municating cords and plexuses become conductors, the gan- 
 glions cease to be .isolating, the impressions are perceived, 
 and the motions are influenced by the animal centre. 
 
 According to Reil also, in the magnetic sleep, the separa- 
 tion of the two nervous centres disappears, and the epigastric 
 nervous centre, the centre of the vegetative sphere, becomes 
 a distinct sense. 
 
 Autenreith considers the sympathetic nerve as arising from 
 the brain and spinal marrow, but becoming more and more 
 independent in proportion as it is separated by plexuses and 
 ganglions, the reddish or grayish substance of the sympathetic 
 nerves conducting impressions and irritations with more diffi- 
 culty than the white. 
 
 Weber has collected together many anatomical and physio- 
 logical arguments, to demonstrate that the sympathetic nerve 
 constitutes a particular system, which, independent of the 
 brain, has its centre within itself. 
 
 Wutzer has observed; as well as Bichat and others, that the 
 mechanical irritation of the sympathetic nerve does not pro- 
 duce any appreciable effect; whilst a more powerful irritant, 
 as galvanism, determines pains and convulsions. 
 
 Broussais considers also the intercostal nerve as a peculiar 
 system, a particular sensitive centre, which transmits impres- 
 sions to the animal sensorium, and consequently determina- 
 
516 GENERAL ANATOMY. 
 
 tions to the voluntary muscles. In the foetus it acts alone, di- 
 rects the secretory and nutritive organs, excites the energy of 
 the heart, extends its action to the animal centre, and deter- 
 mines automatic movements. In anencephalous and amyeles 
 foetuses, it excites muscular movements by its action upon the 
 spinal nerves. After birth, it acts upon the nervous centre, 
 transmitting Jo it the internal sensations, and establishes thus, 
 between the brain and the viscera of the two other cavities, a 
 connexion fertile in phenomena. At all times it rules the ac- 
 tion of the capillary vessels, and directs nutrition through the 
 intermedium of the formative or plastic power, which-this in- 
 genious writer calls vital chemistry. 
 
 815. Almost all these opinions, which consist in consider- 
 ing the system of ganglions as an independent system, err in 
 being too absolute, as well as those which consider in the gan- 
 glions only a purely anatomical arrangement. The system of 
 ganglions ought to bq considered at the same time as a system 
 separate or united, independent or dependent, according to 
 different circumstances for the most part already indicated. 
 
 The functions of the ganglions appear to be to diminish or 
 to arrest the influence of the nervous centre upon the gan- 
 glionary nerves, to diminish or to hinder the transmission of 
 impressions to the centre; so that by the action of the gangli- 
 ons, the vegetative nervous system is separated from the ani- 
 mal system. ' 
 
 The ganglions appear besides to collect, to coerce the nerv- 
 ous power which they draw from the spinal marrow, to devel- 
 ope it by themselves, to communicate it conveniently to the 
 nerves and to the organs where. they terminate. 
 
 The ganglions exercise different functions according to the 
 diversity of their texture. 
 
 These differences consist in, lst r the mixture more or less 
 intimate of the medullary fibres; 2d, the diversity of the se- 
 condary substance; 3d, the differences in the exterior mem- 
 brane, more or less compact, more or less tense; but, it is in . 
 the ganglions of the sympathetic nerve that we observe the 
 greatest intricacy and blending of the medullary filaments, 
 the tenacity and most intimate union of the secondary sub- 
 
ON THE GANGLIONS AND SYMPATHETIC NERVE. 517 
 
 stance, and a membrane or capsule tolerably firm and very 
 adherent to the interior substance. In the spinal ganglions, 
 on. the contrary, the medullary filaments are straight, unmix- 
 ed, and the secondary substance is coarse, loose, and very dis- 
 tinct from tne filaments: these ganglions also are regarded as 
 less perfect than the others; Pfeffinger also thinks that they 
 ought to be excluded from this class of organs. The function 
 of these last ganglions remains otherwise very doubtful. It 
 does not appear, in effect, that they diminish the nervous com- 
 munication; neither can they be considered as the origins of 
 the common motory and sensitive nerves, for the anterior root 
 of the spinal nerves is distinct from them. 
 
 816. The uses of the ganglionary nervous cords are to 
 conduct the nervous influence; but they are conductors, a lit- 
 tle different from the other nerves, from which they differ by 
 approximating to the ganglions: they are imperfect conduct- 
 ors. Mechanical or chemical irritations do not traverse them; 
 but galvanic irritation is conducted by them, and determines 
 either sensations or contractions. It is the same with morbid 
 irritations, as irritations of the intestines, ureters, &c. which 
 are perceived. 
 
 The functions of the sympathetic nerve are to direct nutri- 
 tion and the secretions; to distribute the nervous agent to the 
 heart, the digestive canal, and the urinary and genital organs;' 
 to establish a sympathetic connexion between all the principal 
 organs. It fulfils these different functions without the influ- 
 ence of the will and without consciousness of impressions, the 
 ganglions perfbrming at the same time the office of slight li- 
 gatures, which moderate the transmission of the nervous influ- 
 ence, and of parti c^r centres of activity, which augment and 
 modify its distribution. 
 
 This nerve forms thus a particular system in the general 
 system; it has a 'sphere of peculiar action enclosed within the 
 general sphere. Both nervou| systems have intimate connex- 
 ions; they influence each other reciprocally, especially in a 
 morbid state. 
 
 817. Lobstein has collected several very curious facts re- 
 lative to the morbid alterations of the ganglions and sympathet- 
 
518 GENERAL ANATOMY. 
 
 ic nerves: he has observed the inflammation of the semi-lunar 
 or coeliac ganglions, in cases of chronic abdominal neuropathy, 
 hoopi ng-cough, and tetanus; he has also observed in several cases 
 the inflammation of the cardiac and pulmonary nerves. Au- 
 tenreith has also observed in hooping-cough the inflammation 
 of the par vagum, sympathetic, and cardiac. Duncan has seen 
 in a case of diabetes the abdominal portion of the sympathetic 
 nerve three or four times larger than usual. 
 
 The sympathetic nerves are, like the others, augmented in 
 volume in hypertrophies, diminished, on the contrary, in sim- 
 ple atrophies, as well as in those which result from an acci- 
 dental production infiltrated into the tissue of an organ. 
 
 Many abdominal and thoracic diseases seem besides to de- 
 pend on an irregular action of the sympathetic nerve; and 
 others, very numerous also, on the anormal action of this nerve 
 upon the cerebral nervous centre. 
 
OF ACCIDENTAL PRODUCTIONS. 519 
 
 CHAPTER XI. 
 
 OF ACCIDENTAL PRODUCTIONS. 
 
 818. The productions which occur accidentally in the hu- 
 man organization are humours, concretions, tissues, and living 
 animals. 
 
 These objects do not form a part of the healthy or regular 
 organization: they belong only to morbid anatomy. Their 
 description, or at least their summary indication, here has for 
 its object to complete what has been said, under the head of 
 each tissue in particular, upon the alterations and productions 
 which are peculiar to it. The productions which are under 
 consideration in this chapter, are common to several parts or 
 to the tofality of the organization. 
 
 The knowledge of the accidental productions and alterations 
 is very important to 'the pathological anatomist; for, on the 
 one hand, this knowledge is the basis of pathology; and on 
 the other hand, anatomy being rarely studied upon healthy 
 subjects, but generally upon the bodies of diseased individu- 
 als, the anatomist meets at every instant', in his researches, 
 with alterations of organization and accidental productions. 
 
 SECTION I. 
 
 OF ACCIDENTAL HUMOURS. 
 
 819. The natural humours may be altered in their quan- 
 tity or quality; soTne of these alterations have been indicated. 
 We sometimes find besides humours altogether different from 
 67 
 
520 GENERAL ANATOMY. 
 
 the first. Among these, pus is the only one which is suffi- 
 ciently well known to be described. 
 
 820. Pus* is an accidental humour resulting from a mor- 
 bid secretion, -which is called suppuration. Pus is composed 
 of microscopic globules, similar to those of the blood, disco- 
 vered by Home, floating in a fluid coagulable by the solution 
 of muriate of ammonia. 
 
 It is of a white or yellowish colour, opake, and of the con- 
 sistence of cream. Its consistence and its colour depend upon 
 ttoe proportion of globules to the fluid part. It is heavier 
 than water. It has a taste slightly saline, constant, and a pe- 
 culiar weak odour, a little variable. 
 
 Pus sinks in water, while mucus floats. By agitation pus 
 becomes diluted, mixes with the water, and whitens it uni- 
 formly; mucus, on the contrary, remains in distinct flocculi. 
 Pus coagulates by heat, acids, and alcohol; alkalies render it 
 viscous, thready, and dissolve it. It is composed, according 
 to Schwilgue, of albumen in a particular state, of extractive 
 matter, of a fatty matter, of soda, of muriate of soda, of phos- 
 phate of lime, and of other salts. It resembles much the se- 
 rum of the blood, from which it appears to differ orjy by the 
 state of the albumen and of the extractive matter. Mucus be- 
 comes diluted in water, dissolves by the. addition of sulphuric 
 acid, while pus does not. A solution of caustic alkali dissolves 
 at the same time pus and mucus, and by the addition of water 
 the pus is precipitated alone. These chemjcal characters, and 
 others of the same Jdnd, are not as certain as the action of wa- 
 ter alone, and especially as microscopic observation. 
 
 * "C. Darwin, Experiments establishing the criterion between irmcagi- 
 nous and purulent matter; Lig-htfield, 1780. Brugrnans, Dissertatio de pyo- 
 genia; Groningse, 1785. E. Home, on the properties of pus; London, 1789. 
 Grasmeyer, Mhandlung von dem eiter, &c.; Getting", 1790. Schwilgue, 
 Mtmoire intdit sur lepus, analyst dans la Nosogr. Philos., vol. ii. G. Pear- 
 son, on expectorated matter; .in Phil. Trans., 1*809. Idem, Observations 
 and experiments on pus; ibid., 1810. Rizetti, De phtJiisi pulmonali specim. 
 chim. med.,- in Mem. de Turin, vol. ii. et iii. --Rossi and Michelotti, Analyse 
 premiere du pus,- ibid., vol. iii. E. Home, On the.oonversion of pus into 
 granulations or new flesh; in Phil. Trans., 1819. 
 
OP ACCIDENTAL HUMOURS. 521 
 
 Pus does not always present precisely the same physical 
 qualities and the same chemical properties. It can be distin- 
 guished mto creamy pus, homogeneous, commonly called most 
 laudable; into serous pus, sanious, or purulent serosity, into 
 glareous pus or puriform mucus; into curdled or clotted pus; 
 into concrete or plastic pus. Besides, pus may be mixed with 
 blood, serosity, excrementitious matters, putrid matter, acci- 
 dental tissues, calculi, virulent matter,- &c. 
 
 In all these cases it is composed, according to Pearson, of a 
 white, opaque, and slightly soluble animal oxide, of a limpid 
 fluid, analogous to the serum of the blood, which holds the 
 animal oxide in suspension, but not in a state of solution; and 
 of an innumerable quantity of microscopic globules. The dif- 
 ferences which it presents depend on the different proportions 
 in which these essential materials are found, as well as the 
 substances which may be found there accidentally. 
 
 821. Pus may be formed in the greater part of the organs. 
 
 The tissue in which suppuration is most frequent and seems 
 the most easy, is the mucous membrane. Some hours after 
 the application of an irritating cause, the physical and chemi- 
 cal properties of mucus are seen to change insensibly into those 
 of pus. When the irritation diminishes and ceases, the pro- 
 perties- of pus are seen to change inversely into mucus. The 
 suppuration of the mucous membrane is accompanied with a 
 slight degree of redness and swelling, and very rarely with 
 ulceration. 
 
 The skin suppurates easily whenever it is irritated and the 
 epidermis removed. This may continue indefinitely, if the 
 irritation is continued, or frequently renewed; the skin then 
 takes on the aspect of an inflamed mucous membrane. 
 
 The cellular tissue being exposed by the removal of the 
 skin, the hemorrhage stops; then flows serosity, which by de- 
 grees takes the character of pus. At the same time the wound- 
 ed surface covers itself with a layer of organizable matter, 
 which becomes vascular and covered with granulations. 
 
 The cellular tissue being irritated by a foreign body or by 
 an unknown cause (spina helmontii) inflames; pus forms in 
 the centre of the phlegmon : this pus is enclosed in a mem- 
 
522 GENERAL ANATOMY. 
 
 brane of a new formation, more or less distinct, more or less 
 vascular, according to its age; the surrounding cellular tissue, 
 inflamed and very vascular, has lost its permeability by the 
 interstitial deposition of organizable matter. 
 
 The serous membranes, when they suppurate, present ana- 
 logous changes; they become very vascular and take at length 
 the appearance of mucous membranes. 
 
 822. Boerhaave attributed the origin of pus to the meeting 
 of inflamed organs; Pringle and Gaber attributed it to a change 
 in the serum of the blood; these two opinions, differently mo- 
 dified and combined, have been for a long time and generally 
 adopted. 
 
 The idea that pus is formed in vessels, and that it departs 
 from^them by a secretory action of these organs, was first in- 
 dicated by Dr. Sympson, then by Dehaen, and afterwards-by 
 Dr. Morgan, of. Philadelphia. Hunter and Brugmans have 
 embraced and developed this doctrine, which is now general- 
 ly adopted. 
 
 Suppuration is a morbid secretion. This secretion is al- 
 ways preceded and determined by inflammation; but the in- 
 flammation is more or less evident. Dehaen himself, who 
 expressly admits suppuration without previous inflammation, 
 evidently means to speak only of inflammation with ulcera- 
 tion: in fact, we now well know, what he then announced, 
 that suppuration might take place upon surfaces without altera- 
 tion; he notices, in cases of suppuration without inflammation, 
 plastic productions and adherences which depend, as we know, 
 on inflammation. 
 
 In scrofulous constitutions suppuration is often preceded 
 only by a chronic and latent inflammation, but which does not 
 the less exist, although it is obscure. 
 
 823. Suppuration, when it exists for a long time, and when 
 it takes place on a large surface, becomes, by its association 
 with the functions, an important secretion; thus we should 
 not lightly establish or suppress a suppuration. 
 
 Pus is sometimes the vehicle of virus introduced into the 
 organization; it is considered also, in some cases, as the vehi- 
 cle of the cause of maladies eliminated by the organization. 
 
OF STONY CONCRETIONS. 523 
 
 According to Sir Ev. Home, pus has for its use to furnish, 
 by its coagulation on the surface of suppurating wounds, the 
 materials of the cicatrix, that is to say, the organizable matter 
 of this new tegument. 
 
 SECTION II. 
 
 OF STONY CONCRETIONS. 
 
 824. Concretions or calculi* are solid bodies, more or less 
 hard, wliich form -in the humours contained in the cavities, 
 the reservoirs, and the ducts lined with the mucous mem- 
 brane. This formation is always accompanied by a change of 
 composition more or less evident of the fluids where it takes 
 place. 
 
 825. Intestinal calculi are rare in the human species. 
 These calcul-i, more or less voluminous and numerous, are 
 round or ovoid, yellow or brown: their specific gravity is 1.4. 
 Their nucleus is a biliary calculus, hardened faeces, or a fo- 
 reign body. They are formed of layers, and composed of 
 earthy substance, especially phosphate of lime, and a little 
 animal substance. 
 
 The mucous and sebaceous follicles contain sometimes indu- 
 rated or more or less concrete masses. 
 
 Several instances have been cited of little calculi of phos- 
 phate of lime and animal matter, in the caruncula lachryma- 
 lis, in the tonsils, and in the prostate. 
 
 Stony concretions of the same nature have been found some- 
 times in the lachrymal canal and sac, in the salivary glands 
 and their ducts, and in the pancreas. 
 
 826. The biliary passagest are frequently the seat of cal- 
 
 * Walter, de concrementis terrestribus. Berol., 1775. Vicq. d'Azyr, Jlca- 
 dem. roy. de medicine, ann. 1779. Mosovius, Dissert, de cakulorem anima- 
 lium, corumque imprimis biliariorum origine et natura. Berolini, 1812. * 
 f Soemmering, de Concrementis biliariis carp, humani^ Traject. ad Moen., 
 1795. Thenard, Mem. de la Soc. d'Arcueil, vol. i. 
 
524 GENERAL ANATOMY. 
 
 culi, cholelithi. They are found most often in- 'the gall blad- 
 der; sometimes in the duct us choledochus or the cystic, or 
 hepatic ducts; or in the intestinal canal, and rarely in the 
 roots of the hepatic canal within the liver. The number and 
 size of these calculi vary extremely: from one to several thou- 
 sand have been found in the same gall bladder, from the size 
 of a pullet's egg to that of a millet seed; their colour varies 
 from white to yellow, brown, and black; their surface is 
 rounded or polyhedral, polished or rugose; their consistence 
 varies much; their specific gravity is from 0.20 to 0.35. They 
 are divided, according to Walter, into three kinds: striated or 
 radiated, striati^ lamellated, lamellati, and provided with a 
 rind, cordicati. In the human species these calculi are* formed 
 of cholesterine, of the yellow matter of the bile, and some- 
 times of a little picromel. 
 
 Urinary calculi,* urolithi, are found in the pelvis of the 
 kidney, in the ureter, in the mouth of this canal, in the blad- 
 der, in the urethra, in the prepuce, in the loculi of the bladder, 
 in the ducts of the prostate,, and in accidental urinary cavities 
 and passages. 
 
 The calculi of the pelvis and calices of the kidney, mould 
 themselves in these cavities, when they increase in this place 
 and become ramose like a branch of coral. 
 
 Calculi of the bladder are the most common; sometimes, 
 and it is so ordinarily, there is only one in the bladder, some- 
 times there are several; more than a hundred have been seen. 
 Their size and their weight vary from that of a grain of wheat 
 to that of an infant's head, and to more than six pounds in 
 weight. Their form is round, obround, tetrahedral, cunei- 
 form, or cubic, &c. 
 
 Their surface is smooth, rugose, or mamillary; their colour 
 apd consistence are very variable. They have always a nu- 
 cleus, formed, either of a gravel stone descended from the 
 pelvis of the kidney,' a clot of blood, a flocculus of mucus, or 
 a foreign body. 
 
 *Fourcroy et Vajiquelin, Mem. de Pinst. .Nat., torn. iv. Wollaston, 
 Phibs. Trans., ann. 1797, &c. 
 
OF ACCIDENTAL TISSUES. 525 
 
 They are sometimes homogeneous, frequently formed of 
 superimposed layers, similar or different; at other times mix- 
 ed or heterogeneous, and without layers. 
 
 The calculi of the bladder are composed: 1st, of uric acid; 
 2d, of cystic.oxide; 3d, of phosphate of lime; 4th, of urate of 
 ammonia; 5th/ of ammoniaco-magnesian phosphate; 6th, of 
 oxalate of lime; 7th, of silex; Sth, of carbonate of lime; 9th, 
 of xanthic oxide; 10th, of fibrinous matter; llth, of mucus; 
 and 12th, of phosphate of iron, and magnesia, of carbonate of 
 magnesia, and urate of soda. These substances are found in 
 calculi, either isolated or combined by two, three, four, and 
 five. The most common of all is the calculus of uric acid; 
 then the fusible calculus, composed of the ammoniaco-magne- 
 sian and calcareous phosphates; then the mural calculus, com- 
 . posed of oxalate of lime; then the calculus formed of distinct 
 layers of uric acid and of oxalate of lime, &c. Silex and the 
 cystic oxide, and still more the xanthic oxide and fibrine, are 
 the rarest substances in urinary calculi. 
 
 828. It is said that pisiform calculou* concretions have 
 been found in the spermatic vesicles and ejaculatory ducts. 
 
 Similar little concretions are sometimes found also in the 
 fallopian tubes. As to concretion^ in the uterus, these are for 
 the most part ossified fibrous bodies. However, concretions 
 of phosphate of lime have been found in this organ having a 
 foreign body for a nucleus. 
 
 We are assured that calculous concretions have been found 
 in the excretory ducts of the nipple. 
 
 SECTION III. 
 
 OF ACCIDENTAL TISSUES. 
 
 829. Accidental tissues* are new organs developed in the 
 living body. 
 
 * Laennec, Cours oral de medecine, au College de France, annte 1820-1823. 
 
526 GENERAL ANATOMY. 
 
 These tissues may be divided into two kinds: 1st, tissues 
 analogous to those of the'healthy organization; 
 
 2d. Heterologous tissues or tissues without analogy in the 
 regular organization. 
 
 There are also some accidental tissues, intermediate, so to 
 speak, between the one and the o^her, analogous, if not with 
 any thing in the human organization, at least with that of 
 other animals. 
 
 830. These different kinds of tissues are sometimes iso- 
 lated, at others, and frequently, united or combined with each 
 other. They are even often united with accidental humours, 
 with living animals, with altered humours or tissues, &c. 
 
 831. Among anatomists and pathologists, some (Dupiiy- 
 tren, Cruveilhier, &c.) regard accidental tissues as the result 
 of transformations experienced by the natural tissues: they call 
 the analogous accidental tissues, transformations properly so 
 called, and heterologous tissues, degenerations; others (J. 
 Hunter, Abernethy, Laennec, &c.) regard them as new or 
 epigenetic productions. It is a question very difficult to re- 
 solve; however, the last opinion appears to us the most con- 
 formable to observation. ' 
 
 832. True transformations are very rare, and take place 
 only between nearly similar tissues: thus the cartilages of the 
 larynx change into bone; the mucous membrane exposed to 
 the air changes into skin, as the skin drawn into the interior, 
 by a cicatrix, becomes mucous membrane, &c. It is thus that 
 we see, in trees, roots change into branches, and reciprocally 
 branches into roots. But most of the pretended transforma- 
 tions are only productions: thus a cicatrix is a membrane en- 
 tirely new, and not the result of the transformation of denuded 
 tissues; thus cancer of the neck of the uterus, is the result of a 
 substance of new formation infiltrated into its tissue, which 
 has separated, compressed it, and brought on atrophy, and not 
 the result of a degeneration of this tissue. 
 
OF HETEROLOGOUS ACCIDENTAL TISSUES. 527 
 
 ARTICLE I. 
 OP ANALOGOUS ACCIDENTAL TISSUES. 
 
 833. These tissues resemble more or less perfectly the 
 tissues of the healthy man. 
 
 They are alterable like the natural tissues, and even more so. 
 
 These tissues are of two sorts: 1st, some are the result of 
 the adhesion of the lips, of a solution of continuity, or of re- 
 generation after a loss of substance; 2d, the others are a result 
 of a production altogether accidental. Both have been de- 
 scribed under the head of each tissue (Chap. \ to x). 
 
 834. The demi-analogous tissues are, 1st, some of the 
 above tissues, which do not attain a perfect degree of organi- 
 zation: such are especially cicatrices or. accidental cutaneous 
 productions, the production of the white compact and flaccid 
 tissue, demi-cartilaginous productions, earthy and stony ossi- 
 fications, imperfect corneous productions, &c. ; 2d, there are 
 also the pearly production, analogous to the natatory bladder 
 of fishes, observed in the walls of cysts ; the production of 
 fungus in laminae, etc. 
 
 ARTICLE U. 
 OF HETEROLOGOUS ACCIDENTAL TISSUES. 
 
 835. Heterologous accidental tissues, morbid, or without 
 analogy in the healthy organization, arc numerous. The most 
 common and best characterized are, tubercles, schirrus, the 
 encephaloid tumours and melanosis; some others of more rare 
 occurrence will be indicated hereafter. 
 
 836. These tissues commence probably in the fluid state; 
 but from the moment they are perceptible they are solid. 
 They remain for a greater o* less time in this state, which is 
 called that of crudity or of organization; a state in which they 
 may be compared to zoophytes, in which they present, for the 
 most part, vessels, and are injurious only mechanically* They 
 
 afterwards soften j decompose and liquify. In this state, which 
 68 
 
528 GENERAL ANATOMY. 
 
 Bayle compares to an anticipated death, they cause pains more 
 or less sharp, and sometimes none ; they irritate and inflame 
 the neighbouring parts; they exercise a deleterious action 
 upon the organization, and particularly upon nutrition, even 
 upon that of the bones ; they extend and multiply then more 
 or less rapidly in the organization. 
 
 The origin and cause of these tissues are unknown. They 
 have been regarded as innate or hereditary; as resulting from 
 an aberration of the formative action ; as organized beings de- 
 veloping and dying prematurely in the midst of the organiza- 
 tion ; as products, results of inflammation and irritation, &c. 
 These are so many hypotheses more or less ingenious and 
 more or less well founded. 
 
 These tissues exist under the form of isolated masses, of en- 
 veloped masses, of infiltrations in the tissue of organs, &c. 
 
 Sometimes they exist separately, sometimes combined with 
 each other and with other accidental productions, and with al- 
 tered tissues and humours. 
 
 I. OF TUBERCLES. 
 
 837. The tubercle, or tubercles, for they exist almosjt al- 
 ways in great numbers, constitute the most common morbid 
 tissue. They are called also scrofulous tubercles, because 
 they are met with in most cases of scrofula. 
 
 This tissue exists under the form of isolated or enveloped 
 masses, and under that of infiltration. 
 
 It commences by the gelatiniform state; but this state is 
 perceivable only when the tuberculous substance is infiltrated. 
 
 It afterwards enters into the grayish, transparent, as if demi- 
 cartilaginous state: this is the first distinct period of isolated 
 tubercles; they constitute the miliary granulations of Bayle. 
 
 These grains in enlarging, often unite in a mass; th'ey be- 
 come opaque, yellowish, friable, commencing by the centre. 
 The same change of colour ana* consistence takes place in the 
 state of infiltration ; it is y.et the state of crudity. 
 
 They afterwards soften and liquefy: at this period, or even 
 in the preceding periods, there is produced much new tuber- 
 culous substance, e'ither4n mass, or by infiltration. 
 
* OP THE ENCEPHALOID TUMOUR. 529 
 
 The tuberculous matter, softened more or less completely, 
 into homogeneous pus, or into clotted pus, is evacuated by an 
 opening in the skin or mucous membrane; it is perhaps also 
 sometimes re-absorbed. Sometimes the collection remains in- 
 flamed, ulcerated indefinitely; at others it contracts and be- 
 comes obliterated ; sometimes the membrane of new formation 
 which lines it acquires a demi-mucous or demi-cartilaginous 
 texture, and constitutes a permanent dry fistula ; at others, 
 finally, a friable matter only is found, probably the residue of 
 a re-absorption, the tubercle not having formed an abscess. 
 
 Vessels are never found in tuberculous masses: in the case 
 of tuberculous infiltration, the vessels being compressed and 
 obliterated, shortly disappear. The masses which are devel- 
 oped slowly have a soft or glutinous, cellular, cartilaginous, 
 and sometimes even osseous envelope. 
 
 The tuberculous tissue is found in all the organs, and espe- 
 cially in the lungs; in the natural and accidental cellular tissue, 
 at the surface of serous membranes, but especially in their 
 false membranes, at the free surface of the mucous membrane, 
 and especially that of the intestine, in the lymphatic ganglions, 
 in the glands, in the spleen, in the bones, in the muscular tis- 
 sue, in that of the heart, in the encephalon and in the spinal 
 marrow, and in compound tumours. 
 
 This morbid tissue has been observed in all vertebrate' ani- 
 mals. 
 
 II. OF THE ENCEPHALOID TUMOUR. 
 
 838. The encephaloid or cerebriform tissue is a very com- 
 mon morbid production: it has been confounded under the 
 name of cancer with several others, and especially with schir- 
 rus. Bayle and Laennec were the first who gave an exact de- 
 scription of it It is the medullary cancer, the fungous inflam- 
 mation, the* fungous hematodes of some English writer. 
 
 This tissue exists under the form of denuded or enveloped 
 masses, and also under that of 'infiltration". 
 
 In the state of crudity, it forms masses of various size; each 
 mass is lobed, lobulated, and the lobules are ordinarily turned 
 
530 GENERAL ANATOMY. ' 
 
 like the convolutions of the brain. This tissue is then firm, 
 like the rind of bacon, semi-transparent, without colour, or 
 whitish or grayish; the lobules are united together by an im- 
 perfect cellular tissue, of extreme softness; they become con- 
 founded in proportion as the mass is developed. Numerous 
 vessels, very fine, and with very weak walls, are ramified in 
 this cellular tissue and in the encephaloid substance itself. 
 
 When the development is complete, the encephaloid tumour 
 is of a white colour; violaceous or rose-coloured in different 
 places, either in tints or points. This morbid tissue is then 
 very analogous to the cerebral tissue, but more loose, and less 
 tenacious. It presents otherwise different degrees of consist- 
 ence in the same mass; degrees comparable to those of differ- 
 ent parts of the encephalon. 
 
 The encephaloid masses which are not enveloped by a dis- 
 tinct membrane, are so by a layer of soft cellular tissue; others 
 have a demi-cartilaginous envelope, lined, on the interior, 
 with soft and vascular cellular tissue like the first. Sometimes 
 the cyst is incomplete in its development; in all cases it ap- 
 pears to be posterior in its formation to the substance which it 
 contains. 
 
 The cerebriform infiltration is very common, especially in 
 the tissue of the neck of the uterus; in this state the period of 
 crudity is very short. 
 
 The softening of this tissue gives place to a pultaceous mat- 
 ter of a rose colour. Sometimes then, the vessels giving way, 
 sanguineous infiltration takes place in the cellular tissue, or 
 effusions similar to apoplexy in the softened substance: the 
 blood then concretes, and is in part re-absorbed; sometimes 
 even a membrane like a cyst is formed about the blood; some- 
 times serous infiltrations take place in the surrounding cellu- 
 lar tissue, or serous effusions in the substance itself, which is 
 then fluid like the white softening of the brain. 
 
 Whatever may be the resemblance, in effect very great, be- 
 tween the morbid tissue of which we speak, and the substance 
 of the brain, there is no identity; and we can not admit the 
 opinion of Maunoir, who regards this tissue as the product of 
 an effusion of nervous matter. 
 
OF SCHIRRUS. 531 
 
 When the softening is exterior or in contact with the air, 
 the surface is gray, greenish, fetid, inflamed; sometimes it de- 
 stroys itself by falling into putrefaction. 
 
 This tissue, multiplies itself in the organization, less, how- 
 ever, than the tubercles, especially at the time of the soften- 
 ing. It has a greater tendency than the tubercle to increase 
 or to extend gradually. It does not appear to be susceptible 
 of being eliminated and of curing itself spontaneously. 
 
 It may exist in all the organs: it is observed frequently in 
 the mammae, the testicles, the uterus, the liver, the lungs, the 
 encephalon, the stomach, the periosteum, the dura mater, the 
 bones, their medullary membrane, the serous membranes, the 
 mucous membrane, the muscles, the glands, the lymphatic 
 ganglipns, and in the common cellular tissue. 
 
 III. OF SCHIRRUS. 
 
 839. The schirrous or glue-like tissue is less common 
 than the preceding; it is often confounded with it under the 
 name of cancer. 
 * It exists most commonly under the form of isolated masses. 
 
 In the state of crudity, it is difficult to distinguish it from the 
 tuberculous and encephaloid tissues. It is hard; but its con- 
 sistence varies from that of cartilage, or of the rind of bacon, 
 to that of the iritervertebral ligaments. It creaks under the 
 point of the. scalpel when scraped; it is white, bluish, gray, 
 little coloured or without colour. It is semi-transparent; it 
 forms masses of irregular figures, rarely lobulated, ordinarily 
 homogeneous; it is sometimes divided in the interior by 
 fibrous or cellular intersections: this interior tissue is some- 
 times regularly radiated, like that of a turnip, sometimes alve- 
 olar, sometimes irregular. Distinct vessels are rarely per- 
 ceived in it. 
 
 Schirrus assumes the consistence of jelly, and sometimes, 
 the appearance of syrup, is sometimes colourless, fulvid, or 
 greenish, sometimes grayish, impure, and stained with blood. 
 Sometimes the. softening is gummy, or pultaceous, and at 
 others, like honey. 
 
532 GENERAL ANATOMY. 
 
 This morbid tissue presents a considerable diversity of ap- 
 pearance, both in the state of crudity and in that of softening. 
 Bayle enumerates from five to six species of cancers. Several 
 species of the sarcoma of Abernethy belong to this kind of 
 tissue. 
 
 Schirrus softens sometimes partially, and then it presents 
 the appearance of cicatrices (Nicod.). In a case of this kind, 
 which I have seen recently, it seemed to me what appeared 
 to be cicatrices was the skin remaining sound in small spots 
 in the midst of a very great number of superficial and irregu- 
 lar ulcerations. 
 
 Schirrus has been observed in most parts of the body, in 
 almost all the organs and tissues. 
 
 IV. OF MELANOSIS. 
 
 840. Melanosis,* cancer m&lane of Alibert is a morbid 
 tissue characterized by its black colour, which, noticed at first 
 by some observers, both in man and animals, has been speci- 
 fied and named, some years ago by Laennec. 
 
 This substance exists under the form of isolated masses, 
 denuded or enveloped, under that of infiltration, and of platft 
 at the surface of membranes. 
 
 The masses of melanosis vary, as to size, from the most mi* 
 nute to that of a nut: they exist in a greater or less number 
 in the same individual; they are sometimes tolerably regular, 
 sometimes mamillary, lobulated, sometimes as if formed of 
 laminae twisted or winding. These parts are united together 
 and the masses surrounded by cellular tissue. The vessels 
 surround this tissue, but do not penetrate into the black sub- 
 stance. This substance is black or brown, opaque, inodorous, 
 tasteless, firm, tenacious, and apparently homogeneous; but if 
 it be broken by percussion, and washed with water, the water 
 becomes coloured with brown or black; the tissue loses its 
 colour and remains grayish. 
 
 Melanosis occurs in plates at the surface of the mucous or 
 
 * Breschet, Considerations sur une alteration organiijue appeh'e degtnt- 
 rescence noire, etc. Paris, 1821. 
 
OF CIRRHOSIS, &C. 533 
 
 serous membranes; it is found also infiltrated in the substance 
 of the mucous membrane, false membranes, ganglions, &c. 
 
 Melanosis, examined chemically, appears composed, 1st, of 
 coloured fibrine; 2d, of a blackish colouring matter, soluble 
 in weak sulphuric acid and in the solution of the subcarbonate 
 of soda, and colouring these fluids red ; 3d, of a small quantity 
 of albumen; 4th, of chloruret of sodium, of subcarbonate of 
 soda, of phosphate of lime and oxide of iron. 
 
 The composition of melanosis is then very analogous to that 
 of the clot of the blood, that is to say to the colouring matter 
 and fibrine, both in a particular state; three gross substances 
 are also met with in it. 
 
 Melanosis softens slowly, under the form of blackish bouil- 
 lie; and, according to its seat, this substance becomes effused 
 in the cavities, where it infiltrates in such a manner as to co- 
 lour the humours and tissues. Sometimes, but rarely, subcu- 
 taneous melanosis ulcerates; Dr. Ferrus has observed a case 
 of this sort. In the state of softening, evei^when extreme, 
 this tissue has little tendency to spread or increase; it does 
 not determine in the organization a deleterious action so 
 marked as the preceding. The alterations which have been 
 most often observed are a general decoloration, dropsies, tor- 
 por, a debility analogous to what takes place in the scurvy. 
 
 Melanosis has been found in many parts, and especially in 
 the common cellular membrane, in the muscles, in the heart, 
 in the lymphatic glands, in the orbit, in the eye, in the lungs, 
 the liver, the kidneys, the pancreas, the spleen, the cellular 
 tissue of the mammas, the accidental cellular tissue, &c. 
 
 Melanosis appears to result from an aberration of some of 
 the materials, and especially of the colouring matter of the 
 blood. 
 
 V. OP ciRRHosft &c. 
 
 841. Cirrhosis, or the fulvid morbid tissue, exists some- 
 times under the form of masses; it has been seen also under 
 the form of plates and of a cyst. 
 
 fr In masses, this tissue is fulvid, dull, flaccid, humid, com- 
 pact, analogous to the tissue of the renal capsules: it does not 
 
534 GENERAL ANATOMY. 
 
 present distinct fibres. The masses vary from the size of a 
 grain of millet to that of a cherry stone. They exist some- 
 times in an innumerable quantity. The largest appear squam- 
 ous. 
 
 This tissue softens under the form of greenish brown pu- 
 trescence; its effects, whether local or general, are slightly 
 marked. It exists frequently and very abundantly in the 
 liver, which is then shrivelled, wrinkled, and rugose. It has 
 been seen also in the kidney, the prostate, the epedidymis, 
 the ovarium, and thyroid. 
 
 842. Laennec has designated, under the name of scferose, 
 a tissue very much resembling or identical with the white 
 compact tissue, and which he found infiltrated in the subperi- 
 toneal cellular tissue of the lumbar region in a cancerous in- 
 dividual. It differs from the morbid tissues in that it has not 
 been osberved softened; but it approximates to them by its pro- 
 pensity to spread. 
 
 843. The saftne pathologist has designated, under the name 
 of squirre squammeux, a tissue of a semi-transparent, dull, 
 white, foliated like the flesh of a cod, which he once saw en- 
 closed in a pearly cyst, in a cancerous individual. 
 
 VI. OF COMPOUND MORBID TISSUES. 
 
 844. The morbid tissues are very often associated: their 
 reunion is one of the greatest sources of difficulty in the study 
 of pathological anatomy. 
 
 The composition takes place sometimes by simple juxta-po- 
 sition, and sometimes by an intimate and mutual penetration. 
 
 The most ordinary combinations are, 1st, those of the fibro- 
 cartilaginous and osseous tissues in the cysts which contain 
 vesicular worms ; 
 
 2d. The combination of earthy ossification and of the tuber- 
 cle, especially in the bronchial glands; 
 
 3d. That of the tubercle and encephaloid tissue, frequent 
 in the liver and testicles; 
 
 4th. That of schirrus and earthy ossification, common also 
 in the liver; 
 
 5th. That of all the morbid tissues, with ossifications, with 
 
OF FOREIGN ANIMATED BODIES. 535 
 
 other analogous productions, inflammation, hypertrophy, se- 
 rous, sanguineous, and purulent infiltrations, &c.; which con- 
 stitutes the compound cancers of the stomach, of the mam- 
 moc, &c. 
 
 SECTION IV. 
 
 OP FOREIGN ANIMATED BODIES. 
 
 845. The animals* which are met with in the organiza- 
 tion, and which live at its expense, are, on the one hand intes- 
 tinal worms, and on the other animals attached to the surface 
 of the body, penetrating into its substance, introduced into its 
 cavities, &c. The knowledge of these beings is one of the 
 parts of medical natural history the most difficult and most 
 obscure from the want of exact observations. 
 
 ARTICLE I. 
 OF INTESTINAL WORMS. 
 
 846. Intestinal worms or entozoary,t entozoa (Rudolphi,) 
 are formed, or at least are born and inhabit within the organi- 
 zation; they can not live elsewhere. They are found not only 
 in the alimentary canal and ducts which are inserted in it, 
 but even in the cellular tissue, in the muscles and in the sub- 
 stance of organs which are the most distant from the surfaces 
 of the body, as the brain. Their organization presents many 
 and great varieties (38). Their origin is very obscure. Con- 
 fining ourselves to the indication of those which inhabit the 
 human body, they maybe referred to three orders, viz.: vesi- 
 cular worms, flat worms and cylindrical worms. 
 
 * J. H. loerdens, Em 
 etc., 1801-1802. 
 
 1810. Idem, Ento: Berolini, . 
 
536 GENERAL ANATOMY. 
 
 I. OF VESICULAR WORMS. 
 
 847. Vesicular worms,* Entozoa cystica, (Rud.) con- 
 sist in great part, of a caudal vesicle more or less voluminous, 
 peculiar to a single or common to several worms: the body is 
 depressed or rounded, always very small; the head (wanting 
 in one genus) is furnished with pits (two or four,) with suckers 
 (four,) with a crown of hooks or of four recurved probosces; 
 there is no visible intestinal canal or genital organs. These 
 worms inhabit always the substance of the organs in a distinct 
 cyst; they have been confounded together for a long time, and 
 with cysts, under the name of hydatids. Even now natural- 
 ists reject one or two genera from this order, which consists 
 of the following: JLcephalocystis, Echinococcus, Cysticerus, 
 and Diceras. 
 
 848. The acephalocystis,t a genus established by Laen- 
 nec, but not adopted by Rudolphi, or by Cuvier, consists in 
 a vesicle, without head or body, round or obround, from the 
 size of a little pea to that of a middling apple, with thin and 
 soft, transparent, whitish, homogeneous, fragile walls, filled 
 with a limpid, aqueous, and albuminous fluid. It is doubtful 
 whether spontaneous movements have been observed in it. It 
 appears that these equivocal beings reproduce by interior buds. 
 They have been met with in almost all the organs. Seven or 
 eight species are known. They are always encysted, if we 
 except the clustered mole, which is regarded as the result of 
 the reunion or of the suture of one species of this genus. 
 
 849. The echinococcus, a genus of Rudolphi, which com- 
 prehends perhaps the acephalocystis,and which Cuvier does not 
 admit, consists in a simple or double external vesicle, to the 
 internal surface of which are attached several worms, fine and 
 granulated like grains of sand, whose body is ovoid, and the 
 head (like that of the armed tsenia) furnished with a crown of 
 hooks and suckers. 
 
 * T/aennec, Memoire sur les vers veslculaires, &c., in the Bulletin de fEcok 
 de medicine. Paris, an. xiii. 
 
 f Laennec, he. tit. Ludersen, .Diss. dc hydalidibus; (Jotting 1 ., 1808. 
 H. Cloquet, Faune de mcdecins, torn. i. Paris, 1- 
 
OF THE FLAT WORMS. 
 
 One species, the echinococcus of man, E. hominis, inhabits 
 the viscera of man, and especially the liver. 
 
 850. The cysticercus has the body rounded or depressed, 
 rugose, terminating in a caudal vesicle; its head (like that of 
 the armed tsenia) is furnished with four suckers and with a re- 
 curved proboscis. It inhabits solitarily a very thin cyst. 
 
 Thecysticercusofthecellulartissue,C. ce//t//osa?, has the head 
 square, the neck very short and inflated before, the body cy- 
 lindrical elongated, the caudal vesicle elliptical transversely, 
 and is the species so common in the hog; it is met with some- 
 times in the muscles, the brain, and the heart of man. Some 
 other species are also found in the human body. 
 
 851. The rough diceras, D. rudis, has the body ovoid 
 and depressed; it has a loose tunic; its head is provided with 
 a bifid, rough, filamentous horn. It is not exactly known 
 whether it inhabits the substance of organs. It was discover- 
 ed by Sultzer, in the matters discharged by the action of a 
 purgative. Considered doubtful by Rudolphi, it has been 
 found since by Le Sauvage, de Caen, who has sent individuals 
 to the Societ6 de la Faculte de Medecine, where I saw them. 
 
 II. OF THE FLAT WORMS. 
 
 852. The flat worms are those whose soft and depressed 
 bodies is provided with sucking-pores at its inferior surface 
 or at its extremities, entozoa trematoda, (Rud.), and those 
 whose body is elongated, continuous, or articulated, and the 
 head furnished with pits, with suckers, with one or four pro- 
 bosces, naked or armed, Ent. cestoidea, (Rud.) Both are de- 
 prived of an intestinal canal, and provided with ramified ova- 
 ries. This order comprehends in the human body the genera 
 Txnia, Disfoma, and Polystoma. 
 
 853. The taenia have the body very much elongated, flat, 
 and articulated, and the head furnished with two or four little 
 suckers. Two species are found in man. 
 
 The broad or unarmed taenia, T. lata, Bothriocephalus la- 
 tus, (Bremser, Rud.), has the head nearly square, two naked 
 pit-suckers, the head and the pits, which are marginal, oblong, 
 
538 GENERAL ANATOMY. 
 
 the neck almost wanting, the anterior articulations in the form 
 of wrinkles, those which follow are broad and short, the last 
 elongated; its length is twenty feet or more. This species is 
 common in Switzerland and Russia, very rare in England, 
 Holland, and Germany. It is not found in dead bodies. 
 
 The solitary or armed tsenia, T. solium, called also com- 
 monly, and improperly^ solitary worm, has the head furnish- 
 ed with four suckers, and an obtuse proboscis,* armed with 
 hooks in their centre; the head is hemispherical, and distinct; 
 the neck thickens anteriorly; the anterior articulations are 
 very short, the following elongated, the last longer, all obtuse, 
 provided each with a marginal pore, alternating indefinitely 
 sideways; its length is from five to ten feet and more. This 
 species is common in England, Holland, and Germany. It 
 is sometimes met with in dead bodies. 
 
 Both species are found in France, but particularly the se- 
 cond. They both inhabit the intestinal canal, especially the 
 small intestines. 
 
 854. The distoma, or the fasciola^ (Lin.) has the body 
 soft, depressed, and two solitary pores, one anterior and one 
 ventral. 
 
 The hepatic distoma, D. hepaticum, which has the form of 
 an oval leaf, is met with in the gall bladder of man and of 
 many other animals, particularly of the sheep. 
 
 The polystoma, hexathyridium, (Treuther,) has the body 
 depressed, six anterior pores, one ventral, and one posterior. 
 The P. of the fat, P. pinguicola, which is truncated before, 
 pointed behind, has been met with in a tumour of the human 
 ovary. The polystoma of the veins, P. venarum, appears 
 to be an external worm. (457) 
 
 III. OP CYLINDRICAL WORMS. 
 
 855. The cylindrical worms, Ent. nematoidea, (Rud.), 
 have the body elongated, rounded, and elastic; they have an 
 intestinal canal, terminated by a mouth and anus, genital or- 
 gans, separate on two different individuals. This order com- 
 
OF CYLINDRICAL WORMS. 539 
 
 prebends, in man, the three following genera: Filaria, Tri- 
 chocephahiSj and flscaris. 
 
 856. The ascaris has the body round, tapering at the two 
 ends, the head furnished with three tubercles; the penis of the 
 male is pointed and bifid. Two species are found in the hu- 
 man body. 
 
 The #. lumbricoideS) the head of which is naked, the body 
 several inches long (3 to 12), marked with two opposite fur- 
 rows, the tail a little obtuse, inhabits the small intestines. The 
 #. vermicular 'is , Oxyuris vermicularis, (Bremser), has the 
 head obtuse, furnished with a vesicular membrane on each 
 side; its body is a little thickened anteriorly; the tail of the 
 male is flexed and obtuse; that of the female is straight and 
 flattened. It inhabits the large intestines, especially the rec- 
 tum. 
 
 857. The trichocephalus has the anterior part of the body 
 capillary, the rest suddenly a little more voluminous; the 
 mouth orbicular; the penis simple, and sheathed. 
 
 The T. dispar is found in man: it is unarmed; its capillary 
 part is very long, its head pointed; the body of the female is 
 nearly straight; that of the male is spiral; the sheath of the 
 penis is ovoid. This worm, observed by Morgagni, Wris- 
 berg, Roedorer, and Wagler, is very common. It inhabits the 
 large intestines, and especially the coecum. 
 
 858. The filaria has the body elongated and nearly equal, 
 the mouth orbicular; the penis of the male is pointed and 
 simple. 
 
 The F. medinensis, which is very long, which has the head 
 slender, the tail flattened and flexed in the male, semi-cylin- 
 drical, pointed, and curved in the female, is met with in the 
 human species, but only between the tropics. It inhabits 
 the subcutaneous cellular tissue, especially that of the feet. 
 It was thought formerly to be an exterior penetrating worm; it 
 appears to be really an entozoary one. The F. of the bronchia?, 
 F. bronchialis, is a doubtful species, observed and described 
 by Treutler, under the name of Hamularia lymphatica. 
 
 859. The strongylus gigas has been numbered among the 
 worms which inhabit the human body, because Ruysch says 
 
540 GENERAL ANATOMY. 
 
 that he once saw in the kidneys of man, worms similar to 
 those of the kidneys of the dog. 
 
 The spiroptera hominis is a species yet doubtful, observed 
 by Messrs. Barnett and Lawrence, and discharged from the 
 urinary bladder of a woman. 
 
 H. Cloquet has recently described under the name of Ophi- 
 ostoma ponterii, a worm thrown up by a man in vomiting, 
 and observed by Pontier. 
 
 Many other worms have been indicated as inhabiting the 
 human body, which are only found in animals; others are 
 only larvae, or other objects more or less analogous to the 
 worms which are found accidentally in excretions, or which 
 have been placed there by deception. 
 
 ARTICLE II. 
 OF PARASITIC ANIMALS. 
 
 860. Parasitic animals are much more foreign to the or- 
 ganization than the entozoaric. 
 
 Some of them however are insects born, living, and repro- 
 ducing themselves on the surface and within the substance of 
 the skin: such are the Pediculus humanus corporis, P. capi- 
 tis, P. pubiSj Pulex irritans, P. penetrans, and the Jlcarus 
 scabiei or sarcoptes. 
 
 Other insects are deposited under the skin and in the mu- 
 cous cavities, in the state of eggs, develope themselves in the 
 state of larvae, and come out afterwards: such is the Oestrus, 
 so common in the horse, the ox, the sheep, and which has 
 been found also under the skin of man and in the sinus of the 
 face. Larvae of the genus Musca and of some others, deve- 
 lope themselves also sometimes in the auricular passage of 
 children which are not kept clean, at the surface of ulcers, &c. 
 We must not forget that many cases of larvae excreted should 
 be referred to deceptions or fortuitous cases. 
 
 861. Certain other animals penetrate, in the adult state, 
 into the mucous cavities of the body, remain there a greater 
 
OF PARASITIC ANIMALS. 541 
 
 or less time, and cause different affections: such are, among 
 others, leeches Hirudo medicinalis, and H. alpina; such is 
 probably also the hair-worm, Gordius, It has been thought 
 that the earth-worm could penetrate into the body, it is the 
 effect either of a mistake or of deception. The Furia Inferna- 
 lis of Linnaeus appears to be an imaginary worm. 
 
 Some insects, finally, only mechanically wound the exte- 
 rior surface of the body, or deposit a venom in it; they are 
 otherwise entirely foreign to it. 
 
 THE END. 
 
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 friends, Anna ana Ma 
 
 We would advise so 
 
 aria Jay' but who this fair author is, we cannot ev 
 me sensible educated baekelor to find out." -JV. T. C 
 
 oin. Adv. 
 
 XXII. The PRACTICE of PHYSIC, by W. P. 
 
 DEWEES, M. D. Adjunct Professor of Midwifery in the University 
 of Pennsylvania, 2 vols. 8vo. 
 
 The profession need not be informed how much a work like that now pub- 
 lished was wanted. It has been the particular object of the author to endeavour 
 to accommodate the mode of managing the diseases of which he trciis to the 
 many pathological discoveries recently made, both in this country and i it Europe; 
 and having also availed himself of Jhis long experience, he trusts that his work 
 will remove many of the embarrassments experienced by practitioners. 
 
 XXIII. DEWEES on the DISEASES of CHIL- 
 DREN. Third edition. In 8vo. 
 
 The objects of this work are, 1st, to teach those who have the charge of chil- 
 dren, either as parent or guardian, the most approved methods of securing and 
 improving their physical powers. This is attempted by pointing out the du- 
 ties which the parent or the guardian owes for this purpose, to this interesting, 
 but helpless class of beings, and the manner by which their duties shall be ful- 
 filled. And 2d, to render available a long experience to these objects of our af- 
 fections, when they become diseased. In attempting this, the author has avoided 
 as much as was possible, "technicality;" and has given, if he does not flatter him- 
 self too much, to each disease of which he: treats, its appropriate and designat- 
 ing characters, A\ith a fidelity that will prevent any two being confounded, to- 
 gether with the best mode of treating them, that either his own experience or 
 that of others has suggested. 
 
 XXIV. DEWEES on the DISEASES of FEMALES. 
 
 Second edition with additions. In Svo. 
 
 XXV. DEWEES'S SYSTEM of MIDWIFERY. 
 
 Fourth edition, with additions. 
 
 XXVI. CHAPMAN'S THERA.PEUTICSandMA- 
 
 TERIA MEDICA. Fifth edition, with additions. 
 
 XXVII. The ATLANTIC SOUVENIR, for 1 830, in 
 elegant fancy leather binding 1 , and with numerous embellish- 
 ments by" the best Artists. 
 
 The publishers have spared neither pains nor expepse in endeavouring to 
 render this, their fifth annual volume, still more worthy the high degree of fa- 
 vour which its predecessors have enjoyed. A II the impressions being from steel 
 render them equally perfect, and the binding being a fancy leather, the \\holu 
 will be rendered more permanent. In the list of Authors will be found many 
 of the most distinguished writers in this country. 
 
 A few copies remain unsold of the ATLANTIC SOUVENIR, 
 a Christmas and New Year's Present for 1827, 1828, and 1829, 
 with numerous embellishments by the best Artists. 
 
 XXVIII. A CHRONICLE of the CONQUEST of 
 GRENADA, by WASHINGTON IRVING, Esq. in 2 vols. 
 
 On the whole, this work will sustain the high fame of Washington Irving. 
 It fills a blank in the historical library which ought not to have remained so 
 long a blank. The language throughout is at once chaste and animated; and 
 the narrative may be said, like Spencers Fairy Queen, to present one long gal- 
 lery of splendid pictures. Indeed, we know no pages from which the artist is 
 more likely to derive inspiration, nor perhaps are there many incidents in litei 
 rary history more surprising than that this antique and chivalrous story should 
 have been for the first time told worthily by the pen of an American and a WH 
 publicau."L<mdott Literary Gazette* 
 
Published by Carey fy Lea. 5 
 
 
 Recently published new Editions of the following works 
 
 by the same Author. 
 THE SKETCH BOOK, 2 vols. 12mo. 
 
 KNICKERBOCKER'S HISTORY of NEW YORK, 2 vols. 
 12mo. 
 
 BRACEBRIDGE HALL, 2 vols. 12mo. 
 TALES of a TRAVELLER, 2 vols. 12mo. 
 
 XXIX. NEUMAN'S SPANISH and ENGLISH 
 
 DICTIONARY, new Edition. 
 
 XXX. The WISH-TON-WISH, by the Author of 
 the SPY, PIONEERS, RED ROVER, &c. in 2 vols. 12mo. 
 
 " We can conceive few periods better calculated to offer a promising field to 
 the novelist than that which these pages illustrate; the mingling of w ildest ad- 
 venture with the most plodding industry the severe spirit of the religion of the 
 first American settlers the feelings of household and home at variance with all 
 earlier associations of country the magnificence of the sceneiy by which they 
 were surrounded their neighbourhood to that most picturesque and extraordi- 
 nary of people we call savages; these, surely, are materials for the novelist, and 
 in Mr. Cooper's hands they have lost none of their interest. We shall not attempt 
 to detail the narrative, but only say it is well worthy of the high reputation of 
 its author. All' the more serious scenes are worked up to theTiighest pitch of 
 excitement; if any where we have to complain of aught like failure, it is in the 
 lighter parts, and some of the minor details, which are occasionally spun out 
 too much." London Literary Gazette. 
 
 New Editions of the following Works by the same 
 
 Author. 
 
 The RED ROVER, in 2 vols. 12mo. 
 The SPY, 2 vols. 12mo. 
 The PIONEERS, 2 vols. 12mo. 
 The PILOT, a Tale of the Sea, 2 vols. 12mo. 
 LIONEL LINCOLN, or the LEAGUER of BOSTON, 2 vols. 
 The LAST of the MOHICANS, 2 vols. 12mo. 
 The PRAIRIE, 2 vols. 12mo. 
 
 XXXI. A TOUR in AMERICA, by BASIL HALL, 
 Captain, R. N. in 2 vols. 12mo. 
 
 XXXII. AMERICAN ORNITHOLOGY, or NA- 
 TURAL HISTORY of BIRDS inhabiting the UNITED 
 STATES, by CHARLES LUCIAJT BONAPARTE; designed as a 
 continuation of Wilson's Ornithology, vols. I., H. and III. 
 
 ** Gentlemen who possess Wilson, and are desirous of ren- 
 dering 1 the work complete, are informed that the edition of 
 this work is very small, and that but a very limited number of 
 copies remain unsold. 
 
 XXXI II. The AMERICAN QUARTERLY RE- 
 VIEW, No. XV. Contents. The Gulistan of Sadi. -Napoleon 
 and Bourienne. Anthon's Horace. Falkland and Paul Clif- 
 ford. Tanner's Indian Narrative. Dramatic Literature. 
 British Debate concerning Mexico. Sunday ; Mails. Life of 
 Sir Thomas Munro. Fanatical Guides. Terms, Jive dollars 
 per annum. 
 
 XXXIV. The AMERICAN JOURNAL of the ME- 
 DICAL SCIENCES, No. XII. for August, 1830. Among the 
 Collaborators of this work are Professors Bigelow, Channing, 
 Chapman, Coxe, Davidge, De Butts, Dewees, Dickson, Dud- 
 
Valuable Works 
 
 ley, Francis, Gibson, Godman, Hare, Henderson, Horner, 
 Hosack, Jackson, Macneven, Mott, Mussey, Physick, Potter, 
 Sewall, Warren, and Worthington; Drs." Daniell, Emerson, 
 Fearn, Griffith, Hays, Hayward, Ives, Jackso-n, King, Moultrie, 
 Spence, Ware, and Wright. Terms, five dollars per annum. 
 
 XXXV. EVANS'S MILLWRIGHT and MIL- 
 LER'S GUIDE. New edit, with additions, by Dr. T. P. JOKES 
 
 XXXVI. HUTIN'S MANUAL of PHYSIO- 
 LOGY, in 12mo. 
 
 XXXVII. HISTORICAL, GEOGRAPHICAL, 
 and STATISTICAL AMERICAN ATLAS, folio. 
 
 XXXVIII. MANUAL of MATERIA MEDICA 
 
 and PHARMACY. By H.M.ED WARDS, M.D. andP.VAVASSErn, 
 M. D. comprising a Concise Description of the Articles used 
 in Medicine; their Physical and Chemical Properties; the Bo- 
 tanical Characters of the Medicinal Plants; the Formulae for the 
 Principal Officinal Preparations of the American, Parisian, 
 Dublin, Edinburgh, &c. Pharmacopoeias; with Observations on 
 the Proper Mode of Combining and Administering Remedies. 
 Translated from the French, with numerous Additions and 
 Corrections, and adapted to the Practice of Medicine and to 
 the Art of Pharmacy in the United States. By JOSEPH TOGXO, 
 M. D. Member of the Philadelphia Medical Society, and E. 
 DtrRAin>, Member of the Philadelphia College of Pharmacy. 
 
 " It contains all the pharmaceutical information that the physician can desire, 
 and in addition, a largt-r mass of information, in relation to the properties, &c. 
 of the different articles and preparations employed in medicine, than any of tlve 
 dispensatories, and we think will entirely supersede all these publications in the 
 library of the physician." Am. Journ. of the Medical Sciences. 
 
 XXXIX. An EPITOME of the PHYSIOLOGY, 
 GENERAL ANATOMY, and PATHOLOGY of BICHAT, by 
 THOMAS HENDERSON, M. D. Professor of the Theory and Prac- 
 tice of Medicine in Columbia College, Washington City. 1 
 vol. 8vo. 
 
 " The epitome of Dr. Henderson ought and must find a place in the library 
 of every physician desirous of useful knowledge for himself, or of being instru- 
 mental in imparting it to others, whose studies he is expected to superintend." 
 North American Medical and Surgical Journal, No. 15. 
 
 XL. ADDRESSES DELIVERED on VARIOUS 
 
 PUBLIC OCCASIONS, by JOHN D. GODMAN, M. D. late 
 Professor of Natural History to the Franklin Institute, Profes- 
 sor of Anatomy, &c. in Rutgers College, &c. &c. With an 
 Appendix, containing a Brief Explanation of the Injurious 
 Effects of Tight Lacing upon the Organs and Functions of 
 Respiration, Circulation, Digestion, &c. 1 vol. 8vo. 
 
 XLI. ELLIS' MEDICAL FORMULARY. The 
 
 Medical Formulary, being a collection of prescriptions de- 
 rived from the writings and practice of many of the most emi- 
 nent physicians in America and Europe. To which is added 
 an Appendix, containing the usual dietetic preparations and 
 antidotes for poisons. The whole accompanied with a few 
 brief pharmaceutic and medical observations. By BENJAMIN 
 ELLIS, M. D. Professor of Materia Medica and Pharmacy in the 
 Philadelphia College of Pharmacy. 2d edition, with additions. 
 
Published by Carey fy Lea. 7 
 
 Cf A small and very useful volume has been recently published in this city, en- 
 titled ' The Medical Formulary.' We believe that this volume \\ill meet with a 
 cordial welcome from the medical public. We would especially recommend it 
 to our brethren in distant parts of the country, whose insulated situations may 
 prevent them from having access to tin.- many" authorities which have been con- 
 sulted in arranging materials for this work." Phil. Merl. and Phys. Jour. 
 
 XLll. ELEMENTS of PHYSICS, or NATU- 
 RAL PHILOSOPHY, GENERAL and MEDICAL, explained 
 independently of TECHNICAL MATHEMATICS, and con- 
 taining- New Disquisitions and Practical Suggestions. By 
 NEIL AHNOTT, M. D. First American from the third London 
 edition, with additions, by ISAAC HAYS, M. D. 
 
 *** Of this work four editions" have been printed in England in a very short 
 time. All the Reviews speak of it in the hightest terms. 
 
 XLI1I. LA FAYETTEin AMERICA, in 1824 and 
 
 1825; or a Journal of a Voyage to the United States, by 
 A. LEVASSEUR, Secretary to the General during 1 his journey, 
 2 vols, 12mo. Translated by Joasr D. GODMAX, M. D. 
 
 XL1V. Major LONG'S EXPEDITION to the 
 ROCKY MOUNTAINS, 2 vols. 8vo. with 4to Atlas. 
 
 XLV. Major LONG'S EXPEDITION to the 
 SOURCES of the MISSISSIPPI, 2 vols. 8vo. with Plates. 
 
 XLVI. NOTIONS of the AMERICANS, by a Tra- 
 velling Bachelor, 2 vols. 12mo. By the Author of the SPY, 
 PIONEERS, &c. 
 
 XLVII. The HISTORY of LOUISIANA, particu- 
 larly of the Cession of that Colony to the United States of 
 North America? with an introductory Essay on the Constitu- 
 tion and Government of the United States, byM. DE MARBOIS, 
 Peer of France, translated from the French by an American 
 citizen, in 1 vol. 8vo. 
 
 " From the extracts with which we have indulged our readers, they will be 
 able to form an idea of the character and spirit of'M. de Marbois's performance. 
 The outline which we have drawn, however, does very scanty justice to the me- 
 rits of the whole work, which, we repeat, is in our judgment the best that has re- 
 cently appeared, either at home or abroad, on some of the most important topics 
 Of American history and politics. If we do not agree with all the author's opi- 
 nions, we cannot but accord to him unqualified praise for his fairness, liberality, 
 good judgment, and enlightened views. The volume will be a treasure among 
 the historical annals of the country. We are glad to know that a translation of 
 it by a competent hand is in progress in Paris, and will speedily be published in 
 the United States." Nori h American Review. 
 
 IN THE PRESS, 
 I. The YOUNG LADIES' BOOK, a Manual of 
 
 Instructive Exercises, Recreations and Pursuits. 'With nu- 
 merous plates. 
 
 This is a work recently published by Messrs. Vizetelly, Branston & Co. Lon- 
 don, with upwards of seven hundred embellishments, engraved in a superior 
 style on wood. The volume is a duodecimo of more than five hundred pages, 
 and sells in England for one guinea. It is intended to make the American edi- 
 tion a perfect fac-simile, or as nearly so as practicable in this country, and to a- 
 ford it at 4, neatly bound in silk, and elegantly gilt. This work cannot be 
 classed as Annual, but may be said to be a Perennial, a suitable memorial for all 
 times and seasons. It differs essentially from the whole class of Literary Gifts 
 usually presented to Young Ladies, being a complete manual for all those ele- 
 gant pursuits which grace the person and adorn the mind. The London pub- 
 lishers state that the various subjects of which the volume is composed, have 
 been confined to proficients in their several departments, and the engravings 
 have been executed in the best style of the English artists. 
 
8 Valuable Works, fyc. 
 
 II. CHEMISTRY APPLIED to the ARTS, on 
 
 the basis of Gray's Operative Chemist. In 8vo. with nu- 
 merous plates. 
 
 III. The PRINCIPLES and PRACTICE of 
 
 MEDICINE, by SAMUEL JACKSQX, M. D. 
 
 IV. EXAMINATION of MEDICAL DOC- 
 TRINES and SYSTEMS of NOSOLOGY, preceded by PRO- 
 POSITIONS containing the SUBSTANCE of PHYSIOLOGI- 
 CAL MEDICINE, by F. J. V. BUOUSSAIS, Officer of the 
 Royal order of the Leg-ion of Honour; Chief Physician and 
 First Professor in the Military Hospital for Instruction at Pa- 
 ris, &.c. &c. &c. Third edition. Translated from the French, 
 by ISAAC HAYS, M. D. and R. E. GRIFFITH, M. D. 
 
 V. BECLARD'S GENERAL ANATOMY, in 1 
 
 vol. 8vo. 
 
 VI. FARRADAY'S CHEMICAL MANIPULA- 
 TION, first American, from the second London edition. 
 
 VII. THOMPSON on INFLAMMATION, second 
 
 American, from the second London edition. 
 
 VIII. WILLIAMS on DISEASE of the LUNGS. 
 
 IX. ARNOTT'S ELEMENTS of PHYSICS, or 
 NATURAL PHILOSOPHY, GENERAL and MEDICAL, ex- 
 plained independently of TECHNICAL MATHEMATICS 
 Second volume. 
 
 X. A TREATISE ON FEVER. By SOUTHWOOD 
 SMITH, M. p. Physician to the London Fever Hospital. 
 
 " For simplicity of arrangement, perspicuity of view, power of argument 
 and practical deduction, this Treatise on Fever stands without competition, at 
 the head of all that has been written on this abstruse disease." Westminster 
 Review, Jan. 
 
 "Therein no man in actual practice in this metropolis, who should not pos- 
 sess himself of Dr. Smith's work." London Medical and Surgical Journal, Feb. 
 
 " While the study of this work must be a matter of duty to the members of the 
 medical profession, the general reader will find it perfectly intelligible, and of 
 great practical utility." Monthly Repository, March. 
 
 u With a mind so framed to accurate observation, and logical deduction, Dr. 
 Smith's delineations are peculiarly valuable." Medico-Chir, Jtev. March. 
 
 XI. The MUSSULMAN, by R. R. MADDEN, Esq. 
 author of Travels in Turkey, Egypt, Nubia, and Palestine, in. 
 2 vols. 
 
 ** The portraiture of Turkish life and character, which this work exhibits, has 
 perhaps, never been equalled. The account of Mohamed Ali, the destruction 
 of ithe Mamelukes, the picture of Bedouin warfare, the description of the Der- 
 vish, and of the Arabian Astrologer, are indeed among-the most splendid deli- 
 neations ever introduced into the pages of fiction." Sun. 
 
 . XII. The ARMENIANS, a Tale of Constantino- 
 ple, by J. MACFAtttAND, in 2 vols. 
 
 " The author will appreciate our respect for his talents, when we say that he 
 has done more than any other man to complete the picture of the East, dashed 
 off by the bold pencil of the author of Anastasius." Edin. Lit. Journ. 
 
 XIII. JOURNAL of the HEART, edited by the 
 Authoress of FLIRT ATIOX. 
 
 " This is a most charming and feminine volume, one delightful for a woman 
 to read, and for a woman to have written; elegant language, kind and gentle 
 thoughts, a sweet and serious tone of religious feeling run through every page, 
 and any extract must do very scanty justice to the merit of the whole. *** 
 We most cordially recommend this Journal of the Heart, though we are unable 
 to do it justice by any selection of its beauties, which are too ultimately inter- 
 woven to admit of separation." Literary Gazette. 
 
Philadelphia, May, 1830. 
 Just Published, by Carey <$f Lea, 
 
 And sold in Philadelphia by E. L. Carey $ A. Hart; in New-York 
 by G. $ C. & H. Carvill ; in Boston by Carter & Hendee in Charleston 
 by W. H. JBerreUin New-Orleans by W. M'Kean; by the principal 
 booksellers throughout the Union, 
 
 AND IN LONDON, BY JOHN MILLER, ST. JAMES'S STREET. 
 
 VOLUMES III. 
 
 CONTAINING ABOUT 150O ARTICLES, 
 
 ( To le continued at intervals of three months,) 
 
 OF THE 
 
 ENCYCLOPAEDIA AMERICANA: 
 
 A 
 
 POPULAR DICTIONARY 
 
 OF 
 
 ARTS, SCIENCES, LITERATURE, HISTORY, AND POLITICS, 
 
 BROUGHT DOWN TO THE PRESENT TIME AND INCLUDING A COPIOUS 
 COLLECTION OF ORIGINAL ARTICLES IN 
 
 AMERICAN BIOGRAPHY: 
 
 On the basis of the Seventh Edition of the German 
 
 CONVERSATIONS-LEXICON. 
 
 EDITED BY DR. FRANCIS LIEBER, 
 ASSISTED BY EDWARD WIGGLESWORTH, ESQ. 
 
 To be completed in twelve large volumes, octavo, price to subscribers, boitnd 
 in cloth, two dollars and a half each. 
 
 EACH VOLUME WILL CONTAIN BETWEEN 600 AND 700 PAGES. 
 
 THE CONVERSATION LEXICON, of which the seventh edition in 
 twelve volumes has lately heen published in Germany, origin- 
 ated about fifteen years since. It was intended to supply a want 
 occasioned by the character of the age, in which the sciences, 
 arts, trades, and the various forms of knowledge and of active 
 life, had become so much extended and diversified, that no in- 
 dividual engaged in business could become well acquainted 
 with all subjects of general interest ; while the wide diffusion 
 of information rendered such knowledge essential to the charac- 
 ter of an accomplished man. This want, no existing works 
 were adequate to supply. Books treating of particular branch- 
 es, such as gazetteers, &c. were too confined in character; 
 while voluminous Encyclopaedias were too learned, scientific! 
 
2 ENCYCLOPAEDIA AMERICANA. 
 
 and cumbrous, being usually elaborate treatises, requiring 1 much 
 study or previous acquaintance with the subject discussed. The 
 conductors of the CONVERSATION LEXICON endeavored to select 
 from every branch of knowledge what was necessary to a well- 
 informed mind, and to give popular views of the more abstruse 
 branches of learning and science ; that their readers might not 
 be incommoded, and deprived of pleasure or improvement, by 
 ignorance of facts or expressions used in books or conversation. 
 Such a work must obviously be of great utility to every class of 
 readers. It has been found so much so in Germany, that it 
 is met with everywhere, among the learned, the lawyers, the 
 military, artists, merchants, mechanics, and men of all stations. 
 The reader may judge how well it is adapted to its object, 
 from the circumstance, that though it now consists of twelve 
 volumes, seven editions, comprising about ONE HUNDRED THOU- 
 SAND COPIES, have been printed in less than fifteen years. It 
 has been translated into the Swedish, Danish and Dutch lan- 
 guages, and a French translation Is now preparing in Paris. 
 
 A great advantage of this work is its liberal and impartial 
 character ; and there can be no doubt that a book like the EN- 
 CYCLOPEDIA AMERICANA will be found peculiarly useful in this 
 country, where the wide diffusion of the blessings of education, 
 and the constant intercourse of all classes, create a great de- 
 mand for general information. 
 
 In the preparation of the work thus far, the Editors have 
 been aided by many gentlemen of distinguished ability ; and for 
 the continuation, no efforts shall be spared to secure the aid of 
 all who can, in any way, contribute to render it worthy of 
 patronage. 
 
 The American Biography, which is very extensive, will be 
 furnished by MR. WALSH, who has long paid particular atten- 
 tion to that branch of our literature, and from materials in the 
 collection of which he has been engaged for some years. For 
 obvious reasons, the notices of distinguished Americans will be 
 confined to deceased individuals: the European biography con- 
 tains notices of all distinguished living characters, as well as 
 those of past times. 
 
 The articles on Zoology have been written expressly forthe 
 present edition by DR. JOHN D. GODMAN ; those on Chemistry 
 and Mineralogy, by a gentleman deeply versed in those de- 
 partments of science. 
 
 In relation to the Fine Arts, the work will be exceedingly 
 rich. Great attention was given to this in the German work, 
 and the Editors have been anxious to render it, by the necessary 
 additions, as perfect as possible. 
 
 To gentlemen of the Bar, the work will be peculiarly valua- 
 ble, as in cases where legal subjects are treated, an account is 
 
 
ENCYCLOPEDIA AMERICANA. 3 
 
 given of the provisions of American, English, French, Prussian, 
 Austrian, and Civil Law. 
 
 The Publishers believe it will be admitted, that this work is 
 one of the cheapest ever published in this country. They have 
 been desirous to render it worthy of a place in the best libraries, 
 while at the same time they have fixed the price so low as to 
 put it within the reach of all who read. 
 
 Those who can. by any honest modes of economy, reserve the sum of two 
 dollars and fifty cents quarterly, from their family expenses, may pay for tlris 
 work as fast as it is published ; and we confidently believe that they will find 
 at the end that they never purchased so much general, practical, useful infor- 
 mation at so cheap a rate. Journal of Education. 
 
 If the encouragement to the publishers should correspond with the testimony 
 in favor of their enterprise, and the beautiful and faithful style of its execu- 
 tion, the hazard of the undertaking, bold as it was, will be well compensated; 
 and our libraries will be enriched by the most generally useful encyclopedic 
 dictionary that has been offered to the readers of the English language. Full 
 enough for the general scholar, and plain enough for every capacity, it is far 
 more convenient, in every view and form, than its more expensive and ponder 
 ous predecessors American Farmer. 
 
 The high reputation of the contributors to this work, will not fail to insure 
 it a favorable reception, and its own merits will do the rest. Silliman's Joum. 
 
 The work will be a valuable possession to every family or individual that 
 can afford to purchase it ; and we take pleasure, therefore, in extending ths 
 knowledge of its merits. National Intelligencer. 
 
 The Encyclopaedia Americana is a prodigious improvement upon all that 
 has gone before it; a thing for our country, as well as the country that gave 
 it birth, to be proud of; an inexhaustible treasury of useful, pleasant and fa- 
 miliar learning on every possible subject, so arranged as to be speedily and 
 safely referred to on emergency, as mell as on deliberate inquiry ; and better 
 still, adapted to the understanding^^ put within the reach of the multitude. 
 * * * The Encyclopaedia ArneHNina is a work without which no library 
 worthy of the name can hereafter be made up. Yankee. 
 
 The copious information which, if a just idea of the whole may be formed 
 from the first volume, this work affords on American subjects, fully justifies 
 its title of an American Dictionary; while at the same time the extent, varie- 
 ty, and felicitous disposition of its topics, make it the most convenient and 
 satisfactory Encyclopaedia that we have ever seen. National Journal. 
 
 If the succeeding volumes shall equal in merit the one before us, we may 
 confidently anticipate for the work a reputation and usefulness which ought 
 to secure for it the most flattering encouragement and patronage. -Federal 
 Gazette. 
 
 The variety of topics is of course vast, and they are treated in a manner 
 which is at once so full of information and so interesting, that the work, in 
 stead of being merely referred to, might be regularly perused with as much 
 pleasure as profit. Baltimore American. 
 
 We view it as a publication worthy of the age and of the country, and can- 
 not but believe the discrimination of our countrymen will sustain the publish- 
 ers, and well reward them for this contribution to American Literature. 
 Baltimore Patriot. 
 
 We cannot doubt that the succeeding volumes will equal the first, and we 
 hence warmly recommend the work to the patronage of the public, as being by 
 far the best work of the kind ever offered for sale in this country. U. S. Oat. 
 
 It reflects the greatest credit on those who have been concerned in its pro- 
 duction, and promises, in a variety of respects, to be the best as well as the 
 most compendious dictionary of the arts, sciences, history, politics, biography, 
 &c. which has yet been compiled. The style of the portion we have read 
 is terse and perspicuous ; and it is really curious how so much scientific and 
 other information could have been so satisfactorily communicated in such brief 
 limits. JV. Y. Evening Post. 
 
 A compendious library, and invaluable book of reference. JV. Y. JSmeritm 
 
4 ENCYCLOPAEDIA AMERICANA* 
 
 This cannot but prove a valuable addition to the literature of the age. Msr 
 Advertiser. 
 
 The appearance of the first volume of this valuable work in this country, i 
 an event not less creditable to its enterprising publishers, than it is likely to 
 prove lastingly beneficial to the public. When completed, according to the 
 model presented by the first volume, it will deserve to be regarded as the spirit 
 of all the best Encyclopaedias, since it comprises whatever is really desirable 
 and necessary in them, and in addition, a large proportion of articles entirely 
 original, or expressly written for its page's. This is the condition of all the 
 articles of American Biography, by Mr. Walsh ; those on Zoology, hy Dr. God- 
 rnaii ; and those on Mineralogy and Chemistry, by a gentleman of Boston, 
 distinguished for his successful devotion to those studies. The work abounds 
 with interesting and useful matter, presented in a condensed and perspicuous 
 style; nor is it one of its least commendations that it is to be comprised in 
 twelve octavo volumes, which ma> be placed on an office table, or occupy a 
 shelf in the parlor, ever ready for immediate reference, instead of requiring 
 almost a room to itself, like its ponderous predecessors, the Britannica, Edinr 
 burgensis, &c. 
 
 The vast circulation this work has had in Europe, where it has already been 
 reprinted in four or five languages, not to speak of the numerous German edi- 
 tions, of which SEVEN have been published, speaks loudly in favor of its in- 
 trinsic merit without which such a celebrity could never have been attained. 
 To every n^n engaged in public business, who needs a correct and ample book 
 of reference on various topics of science and letters, the Encyclopedia Ameri- 
 cana will be almost invaluable, lo individuals obliged to goto situation* 
 where books are neither numerous nor easily procured, the rich contents of" 
 these twelve volumes will prove a mine which will amply repay its purchaser, 
 and be with difficulty exhausted, and we recommend it to their patronage in 
 the full conviction of its worth. Indeed it is difficult to say to what class of 
 readers such a book would not prove useful, nay, almost indispensable, sinc 
 it combines a great amount of valuable matter in small compass, and at mode- 
 rate expense, and is in every respect well suited to augment the reader's stock 
 of ideas, and powers of conversation, without severely taxing time or fatiguing 
 attention. These, at least, are our contusions after a close and candid ex- 
 amination of the first volume. Am. D^ttLMvcrtiser. 
 
 We have seen and carefully examined t|fc first volume of the Encyclopaedia 
 Americana, just published by Carey, Lea ma Carey, and think our readers may 
 be congratulated upon the opportunity of making such a valuable accession to 
 their libraries. Aurora. 
 
 The department of American Biography, a subject of which it should be 
 disgraceful to be ignorant, to the degree that many are, is, in this work, a 
 prominent feature, and has received the attention of one of the most indefati- 
 gable writers in this department of literature, which the present age can fur- 
 nish. Boston Courier. 
 
 According to the plan of Dr. Lieber, a desideratum will be supplied ; the snb- 
 stance of contemporary knowledge will be brought within a small compass; 
 and the character and uses of a manual will be imparted to a kind of publica- 
 tion heretofore reserved, on strong shelves, for occasional reference. By those 
 who understand the German language, the Conversation Lexicon is consulted 
 ten times for one application to any English Encyclopaedia. National Gaz. 
 
 The volume now published is not only highly honorable to the taste, ability 
 and industry of its editors and publishers, but furnishes a proud sample of the 
 accuracy and elegance, with which the most elaborate and important literary 
 enterprises may now be accomplished in our country. Of the manner in which 
 the editors have thus far completed their task, it it impossible, in the course of 
 a brief newspaper article, to speak with adequate justice. Boston Bulletin. 
 
 We have looked at the contents, generally, of the second volume of this 
 work, and think it merits the encomiums which have been bestowed OB it in 
 the northern papers. It continues to be particularly rich in the departments 
 of Biography and Natural History. When we look at the large mass of mis- 
 cellaneous knowledge spread before the reader, in a form which has never been 
 equalled for its condensation, and conveyed in a style that, cdnnot be surpassed 
 for propriety and perspicuity, we cannot but think that the American Ency- 
 clopedia deserves a place in every collection, in which works of reference form 
 a portion." Southern Patriot.