MEDICAL 
 
 FROM THE LIBRARY OF 
 FRANK BRANSON PETRIE, M.D. 
 
ZENTMAYER'S AMERICAN CENTENNIAL STAND 
 
THE 
 
 MICROSCOPIST; 
 
 A COMPENDIUM OF 
 
 MICROSCOPIC SCIENCE 
 
 INCLUDING 
 
 THE USE OF THE MICROSCOPE; MOUNTING AND PRESERVING 
 MICROSCOPIC OBJECTS; THE MICROSCOPE IN CHEM- 
 ISTRY, BIOLOGY, HISTOLOGY, BOTANY, 
 GEOLOGY, PATHOLOGY, ETC. 
 
 WITH 
 
 TWO HUNDRED AND FIFTY ILLUSTRATIONS. 
 FOURTH ENLARGED EDITION. 
 
 J. H. WYTHE, A.M., M.D., 
 
 PROFESSOR OF MICROSCOPY AND HISTOLOGY IN THE MEDICAL COLLEGE OF THE 
 PACIFIC, SAN FRANCISCO, CALIFORNIA. 
 
 PHILADELPHIA: 
 
 P. B LA K 1ST ON, SON & CO., 
 
 1012 WALNUT STREET. 
 1883. 
 
Entered according to Act of Congress, in the year 1880, 
 
 By LINDSAY & BLAKISTON, 
 In the Office of the Librarian of Congress, at Washington D. C. 
 
KESPECTFULLY DEDICATED 
 
 TO THE 
 
 SAN FRANCISCO MICROSCOPICAL SOCIETY, 
 
 AS A TESTIMONY 
 
 TO THE 
 
 ZEAL AND INDUSTRY OF ITS MEMBERS 
 
 IN 
 THE PROSECUTION 
 
 OP 
 MICROSCOPIC SCIENCE. 
 
PREFACE. 
 
 THE first and second editions of this work, in 1851 and 
 1853, were intended to furnish a manual on the use of the 
 microscope for physicians and naturalists. The third and 
 present editions aim to be also a compendium of the micro- 
 scopic sciences, but as microscopy reaches its climax in prac- 
 tical medicine this branch of study receives the largest 
 attention. Matters of mere curiosity have been but briefly 
 referred to, while every necessary fact or principle relating to 
 the microscope has been carefully stated and classified. 
 
 By the liberality of the publishers, the chapters on the use 
 of the microscope in Pathology, Diagnosis, and Etiology, 
 which have been added to this edition, have been largely illus- 
 trated with woodcuts from Bindfleisch. 
 
 The Index and Glossary have been combined in this edition 
 so as to be a source of valuable information, and notices of 
 recent additions to the microscope, together with the genera of 
 microscopic plants, have been given in an Appendix. 
 
 No pains have been spared to render this manual a useful 
 companion to the student of Nature, and an aid to the progress 
 of real science. 
 
 July, 1880. 
 
CONTENTS. 
 
 CHAPTER I. 
 HISTORY AND IMPORTANCE OF MICROSCOPY. 
 
 Application of the Microscope to Science and Art Progress of Micros- 
 copy, 17-21 
 
 CHAPTER II. 
 THE MICROSCOPE. 
 
 The Simple Microscope Chromatic and Spherical Aberration Compound 
 Microscope Achromatic Object-glasses Eye-pieces Mechanical Ar- 
 rangements Binocular Microscope, 21-32 
 
 CHAPTER III. 
 MICROSCOPIC ACCESSORIES. 
 
 Diaphragms Condensers Oblique Illuminators Dark-ground ditto Il- 
 lumination of Opaque Objects Measuring and Drawing Objects 
 Standards of Measurement Moist Chamber Gas Chamber Warm 
 Stage Polariscope Microspectroscope Nose-piece Object-finders 
 Micro-photography, 32-48 
 
 CHAPTER IV. 
 
 USE OF THE MICROSCOPE. 
 
 Care of the Instrument Care of the Eyes Table Light Adjustments 
 Errors of Interpretation Testing the Microscope, . . . 48-58 
 
X CONTENTS. 
 
 CHAPTER V. 
 MODERN METHODS OF EXAMINATION. 
 
 Preliminary Preparation of Objects Minute Dissection Preparation of 
 Loose Textures Preparation by Teasing Preparation by Section 
 Staining Tissues Injecting Tissues Preparation in Viscid Media 
 Fluid Media Indifferent Fluids Chemical Reagents Staining Fluids 
 Injecting Fluids Preservative Fluids Cements, . . 58-76 
 
 CHAPTER VI. 
 
 MOUNTING AND PRESERVING MICROSCOPIC OBJECTS. 
 
 Opaque Objects Cells Dry Objects Mounting in Balsam or Dammar 
 Mounting in Fluid Cabinets Collecting Objects Aquaria, 76-83 
 
 CHAPTER VII. 
 THE MICROSCOPE IN MINERALOGY AND GEOLOGY. 
 
 Preparation of Specimens Examination of Specimens Crystalline Forms 
 Crystals within Crystals Cavities in Crystals Use of Polarized 
 Light Origin of Rock Specimens Materials of Organic Origin 
 Microscopic Palaeontology, 84-98 
 
 CHAPTER VIII. 
 THE MICROSCOPE IN CHEMISTRY. 
 
 Apparatus and Modes of Investigation Preparation of Crystals for the 
 Polariscope Use of the Microspectroscope Inverted Microscope 
 General Micro-chemical Tests Determination of Substances Al- 
 kalies Acids Metallic Oxides Alkaloids Crystalline Forms of 
 Salts, 98-115 
 
 CHAPTER IX. 
 
 THE MICROSCOPE IN BIOLOGY. 
 
 Theories of Life Elementary Unit or Cell Cell-structure and Formation 
 Phenomena of Bioplasm Movements of Cells Microscopic Dem- 
 onstration of Bioplasm Chemistry of Cells and their Products Va- 
 rieties of Bioplasm Cell-genesis Reproduction in Higher Organisms 
 Alternation of Generations Parthenogenesis Transformation and 
 Metamorphosis Discrimination of Living Forms, . . 116-127 
 
CONTEXTS. XI 
 
 CHAPTER X. 
 
 THE MICROSCOPE IN VEGETABLE HISTOLOGY AND BOTANY. 
 
 Molecular Coalescence Cell-substance in Vegetables Cell-wall or Mem- 
 brane Ligneous Tissue Spiral Vessels Laticiferous Vessels Sili- 
 ceous Structures Formed Material in Cells Forms of Vegetable Cells 
 Botanical Arrangement of Plants Fungi Protophytes Desmids 
 Diatoms Nostoc Oscillatoria Examination of the Higher Crypto- 
 gamia Examination of Higher Plants, .... 128-157 
 
 CHAPTER XL 
 
 THE MICROSCOPE IN ZOOLOGY. 
 
 Monera Rhizopods Infusoria Rotatoria Polyps Hydroids Acalephs 
 Echinoderms Bryozoa Tunicata Conchifera Gasteropoda 
 Cephalopoda Entozoa Annulata Crustacea Insects Arachnida 
 Classification of the Invertebrata, 158-182 
 
 CHAPTER XII. 
 
 THE MICROSCOPE IN ANIMAL HISTOLOGY. 
 
 Histo-chemistry Histological Structure Simple Tissues Blood Lymph 
 and Chyle Mucus Epithelium Hair and Nails Enamel Connec- 
 tive Tissues Compound Tissues Muscle Nerve Glandular and 
 Vascular Tissue Development of the Tissues Digestive and Circu- 
 latory Organs Secretive Organs Respiratory Organs Generative 
 Organs Locomotive Organs Sensory Organs Organs of Special 
 Sense Suggestions for Practice, 182-226 
 
 CHAPTER XIII. 
 
 THE MICROSCOPE IN PATHOLOGY. 
 
 Preparation of Specimens The Appearance of Tissues after Death De- 
 generation of Tissues The Metamorphoses The Infiltrations In- 
 flammation Resolution and Organization Pathological New Forma- 
 tions New Formation of Pathological Cells Pathological Growths of 
 Higher Animal Tissues Pathological Growths of Connective Tissue 
 Origin Pathological Growths of Epithelial Origin, . . 226-295 
 
Xll CONTENTS. 
 
 CHAPTER XIV. 
 THE MICROSCOPE IN DIAGNOSIS. 
 
 The Blood in Disease Examination of Urine Urea Chlorides Bile 
 Albumen Sugar Urinary Deposits Epithelium Mucus and Pus 
 Blood Spermatozoa Bacteria, Fungi, etc. Tube-casts Crystalline 
 and Amorphous Deposits Pus and Mucus in Diagnosis Examination 
 of Milk Saliva and Sputum Vomited Matters Intestinal Discharges 
 Vaginal Discharges, 295-320 
 
 CHAPTEE XV. 
 
 THE MICROSCOPE IN ^ETIOLOGY. 
 
 Examination of the Air Examination of Soil and Water Examination 
 of Food, etc. Parasites Vegetable Parasites or Epiphytes Fungi 
 Dust or Germ Fungi, Conio or Gymnomycetes Filamentous Fungi, 
 Hyphomycetes Cleft Fungi, Schizomycetes Mould Diseases Fungi 
 of True Parasitic Diseases of the Skin and Mucous Membranes 
 Fungi as Exciters of Fermentation and Putrefaction and Causes of 
 Disease Animal Parasites Protozoa Vermes Arthropoda Dis- 
 ease Germs, 321-344 
 
 APPENDIX Improvements in Microscopes and in Preparations Genera 
 of Cryptogamia, . . . 345-399 
 
 INDEX AND GLOSSARY, 401-434 
 
THE MICROSCOPIST. 
 
 CHAPTER L 
 
 HISTORY AND IMPORTANCE OF MICROSCOPY. 
 
 THE term microscopy, meaning the use of the micro- 
 scope, is also applied to the knowledge obtained by this 
 instrument, and in this sense is commensurate with a 
 knowledge of the minute structure of the universe, so far 
 as it may come under human observation. Physics and 
 astronomy treat of the general arrangement and motions 
 of masses of matter, chemistry investigates their constitu- 
 tion, and microscopy determines their minute structure. 
 The science of histology, so important to anatomy and 
 physiology, is wholly the product of microscopy, while 
 this latter subject lends its aid to almost every other 
 branch of natural science. 
 
 To the student of physical phenomena this subject un- 
 folds an amazing variety developed from most simple 
 beginnings, while to the Christian philosopher it gives the 
 clearest evidence of that Creative Power and Wisdom 
 before whom great and small are terms without meaning. 
 
 In the arts, as well as in scientific investigations, the 
 microscope is used for the examination and preparation of 
 delicate work. The jeweller, the engraver, and the miner 
 find a simple microscope almost essential to their employ- 
 ments. This application of the magnifying power of lenses 
 was known to the ancients, as is shown by the glass lens 
 
 2 
 
18 THE MICROSCOPIST. 
 
 found at Mneveh, and by the numerous gems and tablets 
 so finely engraved as to need a magnifying glass to detect 
 their details. 
 
 In commerce, the microscope has been used to detect 
 adulterations in articles of food, drugs, and manufactures. 
 In a single year $60,000 worth of adulterated drugs was 
 condemned by the Kew York inspector, and, so long as 
 selfishness is an attribute of degraded humanity, so long 
 will the microscope be needed in this department. 
 
 In agriculture and horticulture microscopy affords valu- 
 able assistance. It has shown us that mildew and rust in 
 wheat and other food-grains, the " potato disease," and 
 the " vine disease," are dependent on the growth of minute 
 parasitic fungi. It has also revealed many of the minute 
 insects which prey upon our grain-bearing plants and fruit 
 trees. The damage wrought by these insects in the United 
 States alone has been estimated by competent observers 
 as not less than three hundred millions of dollars in each 
 year. The muscardine, which destroys such large num- 
 bers of silk-worms in France and other places, is caused 
 by a microscopic fungus, the Botrytis bassiana. 
 
 The mineralogist determines the character of minute 
 specimens or of thin sections of rock, and the geologist 
 finds the nature of many fossil remains by their magnified 
 image in the microscope. 
 
 The chemist recognizes with this instrument excessively 
 minute quantities and reactions which would otherwise- 
 escape observation. Dr. Wormley shows that micro- 
 chemical analysis detects the reaction of the 10,000th to 
 the 100,000th part of a grain of hydrocyanic acid, mer- 
 cury, or arsenic, and very minute quantities of the vege- 
 table alkaloids may be known by a magnified view of their 
 sublimates. The micro-spectroscope promises still more 
 wonderful powers of analysis by the investigation of the 
 absorption bands in the spectra of different substances. 
 
 In biology the wonderful powers of the microscope find 
 
HISTORY AND IMPORTANCE OF MICROSCOPY. 19 
 
 their widest range. If we see not life itself, we see its 
 first beginnings, and the process of its development or 
 manifestation. If we see not Mature in her undress, we 
 trace the elementary warp and woof of her mystic drapery. 
 
 In vegetable and animal physiology we see, by its 
 means, not only the elementary unit the foundation-stone 
 of the building but also chambers and laboratories in 
 the animated temple, which we should never have sus- 
 pected tissues and structures not otherwise discoverable 
 not to speak of species innumerable which are invisible 
 to the naked eye. 
 
 In medical science and jurisprudence the contributions 
 of microscopy have been so numerous that constant study 
 in this department is needed by the ph} 7 sician who would 
 excel or even keep pace with the progress of his profes- 
 sion. Microscopy may be truly called the guiding genius 
 of medical science. 
 
 Even theology has its contribution from microscopy. 
 The teleological view of nature, which traces design, re- 
 ceives from it a multitude of illustrations. In this de- 
 partment the war between skeptical philosophy and theol- 
 ogy has waged most fiercely; and it' the difference between 
 living and non-living matter may be demonstrated by the 
 microscope, as argued by Dr. Beale and others, theology 
 sends forth a paean of victory from the battlements of this 
 science. 
 
 The attempts made by early microscopists to determine 
 ultimate structure were of but little value from the im- 
 perfections of the instruments employed, the natural mis- 
 takes made in judging the novel appearances presented, 
 and the treatment to which preparations were subjected. 
 In late years the optical and mechanical improvements in 
 microscopes have removed one source of error, but other 
 sources still remain, rendering careful attention to details 
 and accurate judgment of phenomena quite essential. Care- 
 ful manipulation and minute dissection require a knowledge 
 
20 THE MICROSCOPIST. 
 
 of the effects of various physical and chemical agencies, a 
 steady hand, and a quick-discerning eye. Above all, 
 microscopy requires a cultured mind, capable of readily 
 detecting sources of fallacy, and such a love of truth as 
 enables a man to free himself from all preconceived no- 
 tions of structure and from all bias in favor of particular 
 theories and analogies. What result is it possible to draw 
 from the observations of those who boil, roast, macerate, 
 putrefy, triturate, and otherwise injure delicate tissues, 
 except for the purpose of isolating special structures or 
 learning the effects of such agencies ? Yet many of the 
 phenomena resulting from such measures have been de- 
 scribed as primary, and theories of development have been 
 proposed on the basis of such imperfect knowledge. 
 
 Borelli (1608-1656) is considered to be the tirst who 
 applied the microscope to the examination of animal 
 structure. Malpighi (1661) first witnessed the actual cir- 
 culation of the blood, which demonstrated the truth of 
 Harvey's reasoning. He also made many accurate obser- 
 vations in minute anatomy. Lewenhoeck, Swammerdam, 
 Lyonet, Lieberkuhn, Hewson, and others, labored also in 
 this department. When we remember that these early 
 laborers used only simple microscopes, generally of their 
 own construction, we must admire their patient industry, 
 skilful manipulation, and accurate judgment. In these 
 respects they are models to all microscopists. 
 
 Within the last quarter of a century microscopic ob- 
 servers may be numbered by thousands, and some have 
 attained an eminent reputation. At the present day, in 
 Germany, England, France, and the United States, the 
 most careful and elaborate investigations are being made, 
 older observations are repeated and corrected, new discov- 
 eries are rapidly announced, and the most hidden recesses 
 of nature are being explored. 
 
 It is proposed in this treatise to give such a resume of 
 microscopy as shall enable the student in any department 
 
THE MICROSCOPE. 21 
 
 to pursue original investigations with a general knowl- 
 edge of what has been accomplished by others. To this 
 end a comprehensive view of the necessary instruments 
 and details of the art, or what the Germans call technol- 
 ogy, is first given, and then a brief account of the appli- 
 cation of the microscope to various branches of science, 
 especially considering the needs of physicians and stu- 
 dents of medicine. 
 
 CHAPTER II. 
 
 THE MICROSCOPE. 
 
 The Simple Microscope. The magnifying power of a 
 glass lens (from lens, a lentil ; because made in the shape 
 of its seeds) was doubtless known to the ancients, but only 
 in modern times has it been applied in scientific research. 
 
 The forms of lenses generally used are the double convex, 
 with two convex faces ; piano convex, with one face flat 
 and the other convex; double concave, with two concave 
 faces ; plano-concave, with one flat and one concave face ; 
 and the meniscus, with a concave and a convex face. 
 
 In the early part of the seventeenth century very mi- 
 nute lenses were used, and even small spherules of glass. 
 Many of the great discoveries of that period were made 
 by these means. A narrow strip of glass was softened in 
 the flame of a spirit-lamp and drawn to a thread, on the 
 end of which a globule was melted and placed in a thin 
 folded plate of brass, perforated so as to admit the light. 
 Some of these globules were so small as to magnify sev- 
 eral hundred diameters. Of course, they were inconve- 
 nient to use, and larger lenses, ground on a proper tool, 
 were more common. 
 
 The magnifying power of lenses depends on a few simple 
 
22 THE MICROSCOPIST. 
 
 optical laws, concerning refraction of light, allowing the 
 eye to see an object under a larger visual angle ; so that 
 the power of a simple microscope is in proportion to the 
 shortness of its focal length, or the distance from the lens 
 to the point where a distinct image of the object is seen. 
 This distance may be measured by directly magnifying 
 an object with the lens, if it be a small one, or by casting 
 an image of a distant window, candle, etc., upon a paper 
 or wall. The focus of the lens is the point where the 
 image is most distinct. Different persons see objects 
 naturally at different distances, but ten inches is consid- 
 ered the average distance for the minimum of distinct 
 vision. A lens, therefore, of two inches focal length, 
 magnifies five diameters ; of one inch focus, ten diameters ; 
 of one-half inch, twenty diameters ; of one-eighth inch, 
 eighty diameters ; etc. 
 
 Simple microscopes are now seldom used, except as 
 hand magnifiers, or for the minute dissection and prepa- 
 ration of objects. They are used for the latter purpose, 
 when suitably mounted with a convenient arm, mirror, 
 etc., because of the inconvenience of larger and otherwise 
 more perfect instruments. 
 
 Single lenses, of large size, are also used for concentra- 
 ting the light of a lamp on an object during dissection, or 
 on an opaque object on the stage of a compound micro- 
 scope. 
 
 There are imperfections of vision attending the use of 
 all common lenses, arising from the spherical shape of the 
 surface of .the lens, or from the separation of the colored 
 rays of light when passing through such a medium. 
 These imperfections are called respectively spherical and 
 chromatic aberration. To lessen or destroy these aberra- 
 tions, various plans have been proposed by opticians. For 
 reducing spherical aberration, Sir John Herschel pro- 
 posed a doublet of two plano-convex lenses, whose focal 
 lengths are as 2.3 to 1, with their convex sides together; 
 
THE MICROSCOPE. 23 
 
 and Mr. Codclington invented a lens in the form of a 
 sphere, cut away round the centre so as to assume the 
 shape of an hour-glass. This latter, in a convenient set- 
 ting, is one of the best pocket microscopes. Dr. \Vollas- 
 ton's doublet consists of two plano-convex lenses, whose 
 focal lengths are as 1 to 3, with the plane sides of each 
 and the smallest lens next the object. They should be 
 
 FIG. 1. 
 
 Holland's Triplet. 
 
 about the difference of their focal lengths apart, and a 
 diaphragm or stop an opaque screen with a hole in it 
 placed just behind the anterior lens. This performs ad- 
 mirably, yet has been further improved by Mr. Holland 
 by making a triplet of plano-convex lenses (Fig. 1), with 
 the stop between the upper lenses. 
 
 The Compound Microscope consists essentially of two 
 convex lenses, placed some distance apart, so that the 
 image made by one may be magnified by the other. 
 These are called the object-glass and the eye-glass. In 
 Fig. 2, A is the object-glass, which forms a magnified 
 image at c, which is further enlarged by the eye-glass B. 
 An additional lens, D, is usually added, to enlarge the 
 field of view. This is called the field-glass. Its office, as 
 in the figure, is to collect more of the rays from the 
 object-glass and form an image at F, which is viewed by 
 the eye-glass. 
 
 Owing to chromatic aberration, an instrument ot this 
 kind is still imperfect, presenting rings of color round the 
 edge of the field of view as well as at the edge of the 
 magnified image of an object, together with dimness and 
 
THE MICROSCOPIST. 
 
 confusion of vision. This may be partly remedied by a 
 small hole or stop behind the object-glass, which reduces 
 the aperture to the central rays alone, yet it is still un- 
 
 FIG. 2. 
 
 Compound Microscope. 
 
 satisfactory. Some considerable improvement may result 
 from using Wollaston's doublet as an object-glass, but the 
 
THE MICROSCOPE. 
 
 25 
 
 achromatic object-glasses now supplied by good opticians 
 leave nothing to be desired. 
 
 Object-glasses. A general view of an achromatic object- 
 glass is given in Fig. 3. It is a system of three pairs of 
 lenses, 1, 2, 3, each composed of a double convex of crown 
 glass and a plano-concave of flint, a, 6, c, represents the 
 angle of aperture, or the cone of rays admitted. It is 
 unnecessary to consider the optical principles which un- 
 derlie this construction. Different opticians have different 
 formulae and propose various arrangements of lenses, and 
 there is room for choice among the multitude of micro- 
 scopes presented for sale. For high powers, the German 
 
 Flu. 3. 
 
 FIG. 4. 
 
 Achromatic Object-glass. 
 
 Huygenian Eye-piece. 
 
 and French opticians have lately proposed a princip'e of 
 construction which is known as the immersion system. 
 It consists in the interposition of a drop of water between 
 the front lens of the objective and the covering glass over 
 the object. This form of object-glass is corning into gen- 
 eral use. For the more perfect performance of an objec- 
 tive, it is necessary that it should be arranged for correct- 
 ing the effect of different thicknesses of covering glass. 
 This is accomplished by a fine screw movement, which 
 brings the front pair of lenses (1, Fig. 3) nearer or further 
 from the object. In this way the most distinct and accu- 
 rate view of an object may be obtained. 
 
26 THE MICROSCOPIST. 
 
 Eyepieces. The eye-piece usually employed is the Huy- 
 genian, or negative eye-piece (Fig. 4). This is composed 
 of two plano-convex lenses, with their plane sides next 
 the eye. Their focal lengths are as 1 to 3, and their 
 distance apart half the sum of their focal distances. 
 Several of these, having different magnifying powers, are 
 supplied with good microscopes. It is best to use a weak 
 eye-piece, increasing the power of the instrument by 
 stronger objectives when necessary. Kellner's eye-piece 
 has the lens next the eye made achromatic. The peri- 
 scopic eye-piece of some of the German opticians has both 
 lenses double convex. This gives a larger field of view 
 with some loss of accurate definition. For high powers, 
 I have used a strong meniscus in place of the lower lens 
 in the Huygenian eye-piece. Dr. Koyston Pigott has 
 suggested improvements in eye-pieces by using an inter- 
 mediate Huygenian combination, reversed, between the 
 objective and ordinary eye-piece. This gains power, but 
 somewhat sacrifices definition. Still better, he has pro- 
 posed an aplanatic combination, consisting of a pair of 
 slightly overcorrected achromatic lenses, mounted mid- 
 way between a low eye-piece and the objective. This 
 has a separating adjustment so as to traverse two or 
 three inches. The focal length of the combination varies 
 from one and a half to three-fourths of an inch. The 
 future improvement of the microscope must be looked for 
 in this direction, since opticians seem to have approached 
 the limit of perfection in high power objectives, some of 
 which have been made equivalent to g^th or T Q th of an 
 inch focal length. As an amplifier, I have used a double 
 concave lens of an inch in diameter and a virtual focus of 
 one and a half inches between the object-glass and the 
 eye-piece. If the object-glass be a good one, this will 
 permit the use of a very strong eye-piece with little loss 
 of defining power, and greatly increase the apparent size 
 of the object. 
 
THE MICROSCOPE. 27 
 
 l Arrangements. The German and French 
 opticians devote their attention chiefly to the excellence 
 of their glasses, while the mechanical part of their instru- 
 ments is quite simple, not to say clumsy. They seem to 
 proceed 011 the principle that as little as possible should be 
 done by mechanism, which may be performed by the hand. 
 It is different with English and American makers, some 
 of whose instruments are the very perfection of mechan- 
 ical skill. The disparity in cost, however, for instruments 
 of equal optical power is quite considerable. 
 
 Certain mechanical contrivances are essential to every 
 good instrument. The German and French stands are 
 usually vertical, but it is an advantage to have one which 
 can be inclined in any position from vertical to horizontal. 
 There should be steady and accurate, coarse and fine ad- 
 justments for focussing ; a large and firm stage with ledge, 
 etc., and with traversing motions, so as to follow an object 
 quickly, or readily bring it into the field of view ; also a 
 concave and plane mirror with universal joints, capable 
 of being brought nearer or farther from the stage, or of 
 being turned aside for oblique illumination. Steadiness, 
 or freedom from vibration, is of the utmost importance in 
 the construction, since every unequal vibration will be 
 magnified by the optical power of the instrument. 
 
 Among so many excellent opticians it would be impos- 
 sible to give a complete list of names whose workmanship 
 is wholly reliable, yet among the foremost may be men- 
 tioned Tolles, of Boston ; Wales, of Fort Lee, ^. J. ; Gru- 
 now, of Xew York ; and Zentmayer, of Philadelphia ; 
 Powell & Leland, Ross and Smith, Beck & Beck, of London ; 
 Hartnack and Xachet, of Paris ; Merz, of Munich ; and 
 Gund lach, of Berlin. The optical performance of lenses 
 from these establishments is first class, and the mechanical 
 work of their various models good. The finest instru- 
 ments from these makers, with complete appliances, are 
 quite costly, except the Germans and French, whose ar- 
 
2-$ THE MICROSCOPIST. 
 
 rangements, as we have said, are more simple. Cheaper 
 instruments, however, are made by English and American 
 opticians, some of which are very fine. 
 
 Opticians divide microscopes into various classes, ac- 
 cording to the perfection of their workmanship or the 
 accessories supplied. The best first-class instruments have 
 
 FIG. 5. 
 
 Wenbam's Prism for the Binocular Microscope. 
 
 a great variety of objectives and eye-glasses, mechanical 
 stage with rack-work ; a sub-stage with rack for carrying 
 various illuminators: a stand of most solid construction; 
 and every variety of apparatus to suit the want or wish 
 of the observer. They are great luxuries, although not 
 essential to perfect microscopic work. The second class, 
 or students' microscopes, have less expensive stands, but 
 equal optical powers, with first-class instruments. The 
 
FIG. 6. 
 
 Colli os's Harley Binocular Microscope. 
 
30 THE MICEOSCOPIST. 
 
 third or fourth classes of instruments are intended for 
 popular and educational use, and are fitted not only with 
 stands of more simple workmanship, but with cheaper 
 lenses, although often very good. Some French achro- 
 matic objectives, adapted to this class, are suitable for all 
 but the very finest work. 
 
 Binocular Microscopes. The principle of the stereoscope 
 has been applied to the microscope, so as to permit the 
 use of both eyes. The use of such an instrument with 
 low or medium powers is very satisfactory, but is less 
 available with objectives stronger than one-half inch focus. 
 There are two ways of accomplishing a stereoscopic effect 
 in the microscope. The first and most common is by 
 means of Wenham's prism (Fig. 5), placed above the ob- 
 jective, and made to slide so as to transform the binocular 
 into a monocular microscope. 
 
 The second mode is to place an arrangement of prisms 
 in the eye-piece, so as to refract one-half the image to the 
 right and the other half to the left, which are viewed by 
 the corresponding eyes. In either construction there is a 
 provision made for the variable distance between the eyes 
 of different observers. In the frontispiece is a representa- 
 tion of Zentmayer's grand American microscope, which 
 will afford a good idea of the external appearance of a 
 first-class binocular microscope. Students' and third-class 
 microscopes, as before said, are less complicated and of 
 more moderate cost. The mechanical and optical per- 
 formance of Zentmayer's large instrument leaves scarcely 
 anything to be desired. Instead of the more expensive 
 rack-work stage, a simple form, originally invented by Dr. 
 Keen, of Philadelphia, and copied by Xachet and others, 
 is often employed. It consists of a rotating glass disk, to 
 which is attached a spring, or a V-shaped pair of springs, 
 armed with ivory knobs, which press upon a glass plate 
 in the object-carrier. The motion is exceedingly smooth 
 and effective. 
 
FIG. 7. 
 
 FIG. 8. 
 
 Beck s Large Compound Microscope. 
 
 FIG. 9. 
 
 Hartnack's Small Model Microscope. 
 
 Nachet's Inverted Microscope. 
 
32 THE MICROSCOPIST. 
 
 Fig. 6 shows Collins's Harley binocular microscope, a 
 good second class instrument. 
 
 Fig. 7 represents Beck's large compound miscroscope 
 (monocular) ; and Fig. 8, Hartnack's small model micro- 
 scope, with the body made to incline. - 
 
 Fig. 9, Cachet's inverted microscope, invented by Dr. 
 Lawrence Smith for chemical investigations. 
 
 CHAPTER III. 
 
 MICROSCOPIC ACCESSORIES. 
 
 IN addition to the object-glasses, eye-glasses, mirror, 
 and mechanical arrangement of the microscope, to which 
 reference was made in the last chapter, several accessory 
 instruments will be useful and even necessary for certain 
 investigations. 
 
 The Diaphragm, for cutting off extraneous light when 
 viewing transparent objects, is generally needed. In some 
 German instruments it consists of a cylinder or tube, whose 
 upper' end is fitted with a series of disks having central 
 openings of different sizes. The disk can be adjusted to 
 variable distances from the object on the stage so as to 
 vary its effects. English and American opticians prefer 
 the rotary diaphragm, which is of circular form, perforated 
 with holes of different sizes, and made to revolve under 
 the stage. The gradual reduction of light can be accom- 
 plished by the cylinder diaphragm, since when it is pushed 
 up so as to be near the stage it cuts off only a small part 
 of the cone of rays sent upwards by the concave mirror, 
 but, when drawn downwards, it cuts off more. 
 
 Collins's Graduating Diaphragm, which is made with 
 four shutters, moving simultaneously by acting on a lever 
 
MICROSCOPIC ACCESSORIES. 
 
 33 
 
 handle, so as to narrow the aperture, accomplishes the 
 end most perfectly. (Fig 10.) 
 
 FIG. 10. 
 
 Collins's Now Gr duating Diaphragm. 
 
 Beck's Iris Diaphragm is a further improvement of this 
 sort. 
 
 Condensers. The loss of light resulting from the em- 
 ployment of high powers has led to several plans for con- 
 densing light upon the object. Sometimes a plano-convex 
 lens, or combination of lenses, is made to slide up and 
 
 down 
 
 under the stage. 
 
 A Kellner's eyepiece, or some 
 
 Kio. 11. 
 
 Smith and Beck's Achromatic Condenser. 
 
 similar arrangement, especially if fitted with a special 
 diaphragm, containing slits and holes, some of the latter 
 having central stops, is of very great use. First-class in- 
 struments are fitted up with achromatic condensers (Fig. 
 11), carrying revolving diaphragms, some of whose aper- 
 
 3 
 
34 THE MICROSCOPIST. 
 
 tures are more or less occupied by stops, or solid disks, so 
 as to leave but a ring of space for light to pass through. 
 The effect of these annular diaphragms is similar to an 
 apparatus for oblique illumination. 
 
 The Webster condenser is similar in its optical parts to 
 the Kellner eye-piece, and is provided with a diaphragm 
 plate, with stops for oblique illumination, as well as a 
 
 Fir,. 12 
 
 Webster's Condenser, with Graduating Diaphragms. 
 
 graduating diaphragm for the regulation of the central 
 aperture. This is a most useful accessory. (Fig. 12.) 
 
 Oblique Illuminators Certain fine markings on trans- 
 parent objects can scarcely be made out by central illumi- 
 nation, but require the i^ys to come from one side, so as 
 to throw a shadow. Sometimes this is well accomplished 
 by turning the mirror aside from the axis of the micro- 
 scope, and sometimes by the use of one of the condensers 
 referred to above. Amici's prism, w r hich has both plane 
 and lenticular surfaces, is sometimes used on one side and 
 under the stage, in lieu of the mirror. For obtaining 
 very oblique pencils of light the double hemispherical con- 
 denser of Mr. Reade has been invented. It is a hemi- 
 spherical lens of about one and a half inch diameter, with 
 its flat side next the object, surmounted by a smaller lens 
 of the same form, the flat side of which is covered with a 
 thin diaphragm, having an aperture or apertures close to 
 
MICROSCOPIC ACCESSORIES. 
 
 35 
 
 its margin. These apertures may be Y-shaped, extending 
 to about a quarter of an inch from the centre. 
 
 If the microscope has a mechanical stage, with rack- 
 work, or is otherwise too thick to permit the mirror to 
 be turned aside for very oblique illumination, Cachet's 
 ' will prove of service. I have also contrived a useful 
 oblique illuminator for this purpose, by cementing with 
 Dammar varnish a plano-convex lens on one face of a to- 
 tally-reflecting prism, and near the, upper edge of the 
 other side at 90) an achromatic lens from a French trip- 
 let. The prism is made to turn on a hinge, so that an 
 accurate pencil of light may fall on the object at any 
 angle desired. 
 
 Dark-ground II I >< ruinators. Some beautiful effects are 
 produced, and the demonstration of some structures aided, 
 bv preventing the light condensed upon the object from 
 entering the object-glass. In this way the object appears 
 
 FIG. 13. 
 
 FIG. 14. 
 
 Robert's Illuminator. 
 
 Parabolic Illuminator. 
 
 self-luminous on a black ground. For low powers this 
 can be easily done by turning aside the concave mirror as 
 in oblique illumination, or by employing Noberfs illumi- 
 nator, which is a thick plano-convex lens, in the convex 
 
36 
 
 THE MICROSCOPIST. 
 
 surface of which a deep concavity is made. The plane 
 side is next the object. This throws an oblique light all 
 round the object. A substitute for this, called a spot lens, 
 is often used, and differs only from Robert's in having a 
 central black stop on the plane side instead of a concavity 
 (Fig. 13). A still greater degree of obliquity suitable for 
 high powers must be sought by the use of the parabolic 
 illuminator (Fig. 14). This is usually a paraboloid of glass, 
 which reflects to a focus the rays which fall upon its inter- 
 nal surface, while the central rays are stopped. 
 
 Illuminators for Opaque Objects. Ordinary daylight is 
 hardly sufficient for the illumination of opaque objects, 
 
 FIG. 15. 
 
 Bull's-eye Condenser. 
 
 so that microscopists resort to concentrated lamplight, etc. 
 Gas, paraffine, and camphene lamps, have been variously 
 modified for this purpose, but few are better than the Ger- 
 
MICROSCOPIC ACCESSORIES. 37 
 
 man student's Argand lamp for petroleum or kerosene 
 oil, as it is called. To concentrate the light from such a 
 source a condensing lens is used, either attached to the 
 microscope or mounted on a separate stand. Sometimes 
 a bull's-eye condenser is used for more effective illumination 
 (Fig. 15). This is a large plano-convex lens of short focus, 
 mounted on a stand. For such a lens the position of least 
 spherical aberration is when its convex side is towards 
 parallel rays ; hence, in daylight, the plane side should be 
 next the object. But, if it is desired to render the diverg- 
 
 FIG. 16. 
 
 Parabolic Speculum. 
 
 ing rays of a lamp parallel, the plane side should be next 
 the lamp, and rather close to it. The use of this con- 
 denser will also commend itself, when used as last referred 
 to, in microscopic dissection. It will throw a bright light 
 from the lamp directly on the trough, watch-glass, etc., in 
 which the specimen is being prepared. The Lieberkuhn^ 
 or a concave speculum attached to the object-glass, and 
 reflecting the light from the mirror directly upon the 
 object, is one of the oldest contrivances for the illumina- 
 tion of opaque objects ; but the most convenient instru- 
 ment is the parabolic speculum (Fig. 16), a side mirror with 
 
38 THE MICROSCOPIST. 
 
 a parabolic surface attached to the objective. For high 
 powers, a lateral aperture above the objective has been 
 made to throw the light down through the object-glass 
 itself by means of a small reflector, as devised by Prof. 
 Smith, or a disk of thin glass, as in Beck's vertical illumi- 
 nator. This latter is attached to an adapter interposed 
 between the objective and the body of the microscope. 
 
 Instruments for Measuring and Drawing Objects. Screw 
 micrometers are sometimes used with the microscope, as 
 with the telescope, for the measurement of objects ; but 
 the less expensive and simpler glass micrometers have 
 generally superseded them. The latter are of two sorts, 
 the stage and the ocular micrometer. The stage micrometer 
 is simply a glass slide, containing fine subdivisions of the 
 inch, line, etc., engraved by means of a diamond point. 
 Jn case the rulings are T Jo tns anc ^ iVoot ns of an inch, it 
 is evident that an object may be measured by comparison 
 with the divisions ; yet, in practice, it is found incon- 
 venient to use an object with the stage micrometer in this 
 way, and it will be found better to combine its use with 
 that of the drawing apparatus, as hereafter described. 
 The ocular, or eye-piece micrometer, is a ruled slip of glass 
 in the eye-piece. Its value is a relative one, depending on 
 the power of the objective and the length of the micro- 
 scope tube. By comparing the divisions with those of the 
 stage micrometer their value can be readily ascertained. 
 Thus, if five spaces of the eye-piece micrometer cover one 
 space of the stage micrometer, measuring y^^th of an 
 inch, their value will be ^oo^ f an i nc h each. 
 
 Different standards of measurement are used in different 
 countries. English and American microscopists use the 
 inch. In France, and generally in Germany, the Paris 
 line or the millimetre is used. The millimetre is 0.4433 of 
 a Paris line and 0.4724 of an English line ( /..th of an 
 inch). 
 
 In the French system the fundamental unit is the metre, 
 
MICROSCOPIC ACCESSORIES. 
 
 39 
 
 which is the ten-millionth part of the quadrant of the 
 meridian of Paris. The multiples are made by prefixing 
 Greek names of numbers, and the subdivisions by prefix- 
 ing Latin names Thus, for decimal multiples, we have 
 deco, hecto, kilo, and myrio ; and, for decimal subdivisions, 
 deci, centi, and milli. The following may serve for con- 
 verting subdivisions of the metre into English equiva- 
 lents : 
 
 A millimetre equals 0.03937 English inches. 
 
 A centimetre " 0.39371 " 
 
 A decimetre " 3.93708 " 
 
 One inch = 2.539954 centimetres, or 25.39954 millimetres. 
 
 For drawing microscopic objects the camera lucida will 
 be found useful. This is a small glass prism attached to 
 the eye-piece. The microscope is inclined horizontally, 
 
 17. 
 
 Oberhauser's Drawing Apparatus. 
 
 and the observer, looking into the prism, sees the object 
 directly under his eye, so that its outlines may be drawn 
 on a piece of paper placed on the table. Some practice, 
 however, is needed for satisfactory results. For the up- 
 right stands of German and French microscopes, the camera 
 lucida of Chevalier & Oberhauser is available. This is a 
 prism in a rectangular tube, in front of which is the eye- 
 piece, carrying a small glass prism (c, Fig. 17), surrounded 
 
40 THE MICROSCOPIST. 
 
 by a black metal ring. A paper placed beneath is visible 
 through the opening in the ring, and the image reflected 
 by the prism upon it can be traced by a pencil. It is neces- 
 sary to regulate the light so that the point of the pencil 
 may be seen. 
 
 Dr. Beale has recommended, in lieu of the camera lucida, 
 a piece of slightly tinted plate glass (Fig. 18), placed in a 
 short tube over the eye-piece at an angle of 45. This is 
 a cheap and effective plan. A similar purpose is served 
 
 FIG. 18.. Fir,. 19. 
 
 Beale's Tint-glass Camera. Scemin.-ring's Steel Disk. 
 
 by a little steel disk, smaller than the pupil of the eye, 
 placed at the same angle (Fig. 19). 
 
 The most simple method of measuring objects is to 
 employ one of the above drawing instruments, placing 
 first on the microscope stage an ordinary micrometer, and 
 tracing its lines on the paper. Then the outline of the 
 object can be traced and compared with the lines. The 
 magnifying power of an object-glass can also be readily 
 found by throwing the image of the lines in a stage 
 micrometer upon a rule held ten inches below the eye- 
 piece, looking at the magnified image with one eye and 
 at the rule with the other. Dr Beale strongly urges 
 observers to delineate their own work on wood or stone, 
 since they can do it more exactly and truthfully than the 
 
MICROSCOPIC ACCESSORIES. 41 
 
 | 
 
 most skilled artists who are unfamiliar with microscopic 
 manipulation. 
 
 Other accessory apparatus, such as a frog-plate, for more 
 readily observing the circulation in a frog's foot ; an 
 animalcule cage, or live box ; a compressor ium, for apply- 
 ing pressure to an object ; fishing tubes ; watch-glasses ; 
 growing-slides, etc., will commend themselves on personal 
 inspection. 
 
 For preventing the evaporation of fluids during obser- 
 vation, Recklinghausen invented the moist chamber (Fig. 
 20), consisting of a glass ring on a slide,. to which is fas- 
 tened a tube of thin rubber, the upper end of which is 
 fastened round the microscope tube with a rubber band. 
 
 FIG. 20. 
 
 Keckliugliausei.'s M..ist i liambor. 
 
 A simpler form of moist, chamber may be made by a 
 glass ring cemented on a slide. A few drops of water 
 cautiously put on the inner edge of the ring with a brush, 
 or a little moist blotting-paper may be placed inside. The 
 object (as a drop of frog's blood, etc.) may then be put on 
 a circular thin cover, which is placed inverted on the ring. 
 A small drop of oil round the edge of the cover keeps it 
 air and water-tight. 
 
 Somewhat similar to the above is Strieker ' gas chamber 
 (Fig. 21). On the object-slide is a ring of glass, or putty, 
 with its thin cover. Through this ring two glass tubes 
 are cemented, one of which is connected with a rubber 
 
42 
 
 THE MICROSCOPIST. 
 
 tube for the entrance of gas, while the other serves for 
 its exit. 
 
 For the study of phenomena in the fluids y etc.,of warm- 
 blooded animals, we need, in addition to the moist cham- 
 ber, some way of keeping the object w r arm. This may be 
 roughly done by a perforated tin or brass plate on the 
 stage, one end of which is warmed by a spirit-lamp. A 
 piece of cocoa butter or wax will show by its melting 
 when the heat is sufficient. Schultze's warm stage is a 
 
 7 
 
 more satisfactory and scientific instrument. It is a brass 
 plate to fit on the stage, perforated for illumination, and 
 connected with a spirit-lamp and thermometer, so that 
 
 FIG. 21. 
 
 Strieker's Gas Chamber. 
 
 the amount of heat may be exactly regulated. Other 
 arrangements have been proposed to admit a current of 
 warm water, or for the passage of electricity through an 
 object while under observation, which are scarcely neces- 
 sary to describe. 
 
 The Polariscope. The nature and properties of polarized 
 light belong rather to a treatise on optics or natural phi- 
 losophy than to a work like the present, yet a very brief 
 account may not be out of place. We premise, then, that 
 every ray or beam of common light is supposed to have 
 at least two sets of vibrations, vertical and horizontal. 
 As these vibrations have different properties, the ray when 
 
MICROSCOPIC ACCESSORIES. 
 
 43 
 
 divided is said to be polarized, from a fancied resemblance 
 to the poles of a magnet. The division of the vibrations 
 may be effected (i. <?., the light may be polarized) in vari- 
 ous ways. For the microscope the polarizer is a Nichol's 
 prism, composed of a crystal of Iceland spar, which has 
 been divided and again cemented with Canada balsam, so 
 as to throw one of the doubly refracted rays aside from 
 the field of view (Fig. 2*2). Such a prism is mounted in 
 a short tube and attached to the under side of the stage. 
 In order to distinguish the effects of polarized light, an 
 analyzer is also needed. This usually consists of another 
 
 FIG. 22. 
 
 Nichol's Piisin. 
 
 Polarizer and Analyzer. 
 
 similar Xichol's prism, attached either to the eye-piece or 
 just above the objective. The latter position gives a 
 larger field, but the former better definition. Fior. 23 
 shows the polarizer and the analyzer. The polarizer is 
 improved by the addition of a convex lens next the object. 
 Hartnack has also improved the eye-piece analyzer by 
 adding a graduated disk and vernier. 
 
 "When the polarizer and analyzer have been put in place, 
 they should be rotated until their polarizing planes are 
 parallel, and the mirror adjusted so as to give the most 
 intense light. If now the polarizing planes are placed at 
 right angles, by turning one of them 90, the field is ren- 
 
44 
 
 THE MICROSCOPIST. 
 
 dered dark, and doubly refracting bodies on the stage of 
 the microscope appear either illuminated or in colors. If 
 a polarized ray passes through a doubly refracting film, 
 as of selenite, it forms two distinct rays, the ordinary 
 and the extraordinary ray. Each of these will be of dif- 
 ferent colors, according to the thickness of the film. If 
 one be red, the other will be green, these colors being 
 complementary. By using the analyzer one of these rays 
 is alternately suppressed, so that on revolving the appa- 
 ratus the green and red rays appear to alternate at each 
 quarter of a circle. Films of selenite are often mounted 
 so as to revolve between the polarizer and the stage. 
 Barker's selenite stage is sometimes used for this purpose 
 i^. 24). With such a stage a set of selenites is usually 
 
 Fis. 24. 
 
 Barker's Selenite Stage. 
 
 supplied, giving the blue, purple, and red, with their com- 
 plementary colors, orange, yellow, and green. By this 
 combination all the colors of the spectrum may be ob- 
 tained. The selenite disks generally have engraved on 
 them the amount of retardation of the undulations of 
 white light, thus : J, f , and \. If these are placed so 
 that their positive axes (marked PA) coincide, they give 
 the sum of their combined retardations. 
 
 The Microspectroscope.* Ordinary spectrum analysis, by 
 determining the number and position of certain narrow 
 lines in the spectra of luminous bodies, called Fraunhofer's 
 
MICROSCOPIC ACCESSORIES. 
 
 45 
 
 lines, enables the chemist to identify different substances. 
 The object of the microspectroscope is different. It en- 
 ables us to distinguish substances by the absence of cer- 
 tain rays in the spectrum, or, in other words, to judge, of 
 substances by a scientific examination of their color. The 
 color of a body seen with the naked eye is the general 
 impression made by the transmitted light, and this may 
 be the same although the compound rays may differ 
 
 Fl i. 25. 
 
 The Sorby-Browning Microspectroscope. 
 
 greatly, so that colors which seem absolutely alike may 
 be distinguished by their spectra. Many solutions are 
 seen to absorb different colors in very definite parts of the 
 spectrum, forming absorption bands or lines, varying in 
 width and intensity according to the strength of the so- 
 lution. The instrument usually employed consists of a 
 direct-vision spectrum apparatus attached to the eye piece 
 of the microscope, which shows the principal Fraunhofer 
 
46 
 
 THE MICROSCOPIST. 
 
 lines by daylight, or a spectrum of the light transmitted 
 by any object in the field of view. A reflecting prism is 
 placed under one-half of the slit of the apparatus so as to 
 trajftnrit from a side aperture a standard spectrum for 
 comparison. In tfig. 25, A is a brass tube carrying the 
 compound direct-vision system of five prisms and an 
 achromatic lens. This tube is moved by the milled head 
 
 FIG. 20. 
 
 Spectroscope with Micrometer. 
 
 B, so as to bring to a focus the different parts of the 
 spectrum. This is important when the bands or lines to 
 be examined are delicate. D is the stage on which objects 
 for comparison are placed. The light passing through 
 them from the mirror I, goes through a side opening to a 
 reflecting prism which covers a part of a slit in the bot- 
 tom of the tube A. This slit is opened and shut by means 
 of the screws c and H. Fig. 26 shows the internal ar- 
 
MICROSCOPIC ACCESSORIES. 47 
 
 rangement of the prisms and lens, together with a microm- 
 eter for measuring the . position of lines or absorption 
 bands. To use the microspectroscope, remove the, tube 
 A, with the prisms, and insert the tube G in the pla*e of 
 the eye-piece of the microscope. With the lowest power 
 object-glass which is suitable, and the slit opened wide by 
 the screw H, the object on the stage of the microscope, 
 illuminated by the mirror or condenser, is brought to a 
 focus, the tube A replaced and adjusted for focus by the 
 screw B, while the slit is regulated by c and H until a well- 
 defined spectrum is seen. To determine the position of 
 the absorption lines, remove the upper cover of the tube 
 A and replace it with that carrying the micrometer repre- 
 sented in Fig. 26. The mirror illuminates a transparent 
 line or cross, whose image is refracted by a lens c," mov- 
 able by a screw B, and reflected at an angle of 45 from 
 the upper surface of the prisms, so as to be seen upon the 
 spectrum. By means of the micrometer screw M, this is 
 made to move across the spectrum, so that the distance 
 between the lines may be determined. In order to com- 
 pare the results given by different instruments, the 
 observer should measure the position of the principal 
 Fraunhofer lines in bright daylight, and mark them on 
 a cardboard scale, which may be preserved for reference. 
 By comparing the micrometric measurement of lines in 
 the spectrum of any substance observed by artificial light 
 with such a scale, their position may readily be seen. 
 
 In using the microspectroscope some objects require a 
 diaphragm of small size, and others, especially with the 
 1} or 2-inch objective, a cap with a hole j'gth of an inch 
 in diameter over the end of the microscope, to prevent 
 extraneous light from passing through the tube. 
 
 ^ose-piece. For the purpose of facilitating observations 
 with objectives of different powers a revolving nose-piece 
 has been contrived, carrying two, three, or four objectives, 
 
48 THE MICROSCOPIST 
 
 which may be brought quickly into the axis of the instru- 
 ment. 
 
 Object-finders. It is sometimes tedious to find a small 
 object on a slide, particularly with high powers, and a 
 number of contrivances, as Maltwood's finder, have been 
 proposed for this end. A very simple method, however, 
 may serve. Mark on the stage two crosses, one like the 
 sign of addition -f, and the other like the sign of multi- 
 plication x , and, when the object is found, mark the slide 
 to correspond with the marks below. If the stage be a 
 mechanical one it will be necessary to arrange it in the 
 previous position. 
 
 Microscopic Photography. Many European experimen- 
 ters have succeeded in taking microscopic photographs, 
 but a great advance in this direction has been made under 
 the direction of the medical department of the United 
 States army at Washington. Lieutenant-Colonel Wood- 
 ward has succeeded in furnishing permanent records of 
 many details of structure, which exhibit the very perfec- 
 tion of art. In a work like the present a full account of 
 the apparatus and methods employed would be out of place. 
 Dr. Beale's How to Work with the Microscope, and the re- 
 ports issued from the Surgeon-General's office at Wash- 
 ington, will give the details. 
 
 CHAPTER IV. 
 
 USE OF THE MICROSCOPE. 
 
 Care of the Instrument. But little satisfaction will be 
 secured in microscopic work for any length of time with- 
 out scrupulous care of the lenses, etc., belonging to the 
 instrument, and habits of this kind should be early ac- 
 quired. When in frequent use the microscope should be 
 
USE OF THE MICROSCOPE. 49 
 
 seldom packed away in its case, as a certain necessary 
 stiffness of motion in its various parts might thereby 'be 
 lessened. Yet it should be kept free from dust and damp. 
 A bell-glass cover, or glass case, or a cabinet which will 
 admit the reception of the instrument in a form ready for 
 immediate use, is desirable. Before using, the condition 
 of objective and eye-piece should be examined as well as 
 of the mirror, and dust or dampness removed. Another 
 examination should be made before the microscope is put 
 away. 
 
 Stains on the brass-work may be removed by a linen 
 rag, and dust on the mirror and lenses by a fine camel's- 
 hair brush, or very soft and clean chamois skin. Frequent 
 wiping will injure the polish of the lenses. 
 
 The upper surfaces of the lenses in the eye-pieces and 
 the mirror will need the most frequent attention The 
 objectives, if carefully handled and kept in their boxes 
 when not in use, will seldom require cleaning If the front 
 of the objective becomes accidentally wet with fluid it 
 should be at once removed, and, when reagents are used, 
 great care should be taken to prevent contact with the 
 front of the lens. 
 
 Care of the Eyes. Continuous observation, especially by 
 lamplight, and with high powers, has doubtless a ten- 
 dency to injure the sight. To cease work as soon as 
 fatigue begins is, however, a simple but certain rule for 
 protection. This time will vary greatly, according to the 
 general tone and vigor of the observer. It is also impor- 
 tant to use the eyes alternately if a monocular instrument 
 is employed, as otherwise great difference both in the 
 focus and in the sensitiveness of the eyes will result. The 
 habit of keeping the unemployed eye open is a good one, 
 and, though troublesome at first, is not difficult to ac- 
 quire. It is well to protect the eye from all extraneous 
 light, and to exclude every part of the object except that 
 which is under immediate observation. The diaphragm 
 
 4 
 
50 THE MICROSCOPIST. 
 
 will serve this end as well as modify the quality of the 
 light. For very delicate observations a dark shade over 
 the stage, which may be fastened by an elastic ring to 
 the microscope-tube, so as to shut off extraneous light, 
 will be useful. 
 
 Table, etc. The microscopist's work-table should be 
 large and massive, so as to be convenient and free from 
 vibration. Drawers for accessories and materials used in 
 preparing and mounting objects are also desirable, as well 
 as a few bell-glasses for secluding objects from dust. Re- 
 agents should always be removed from the table after use 
 and kept in another place. 
 
 Light. Dr. Carpenter has well said, " Good daylight is 
 to be preferred to any other kind of light, but good lamp- 
 light is preferable to bad daylight." A clear blue sky 
 gives light enough for low powers, but a dull white 
 cloudiness is better. The direct rays of the sun are too 
 strong, and should be modified by a white curtain, reflec- 
 tion from a surface of plaster of Paris, or, still better, by 
 passing through a glass cell containing a solution of am- 
 monio-sulphate of copper. 
 
 Various kinds of lamps have been contrived for micro- 
 scopic use ; among the best are the German and French 
 " student's reading lamps," which burn coal oil or petro- 
 leum. It is often useful to moderate such a light by the 
 use of a chimne} T of blue glass, or by a screen of blue glass 
 between the flame and the object. Dr. Curtis contrived 
 a useful apparatus, consisting of a short petroleum lamp 
 placed in an upright, oblong box. On one side of the box 
 is an opening occupied with blue glass ; on another side 
 the opening has ground-glass, as well as a piece colored 
 blue, and a plano-convex lens so placed as to condense the 
 light thus softened to a suitable place on the table. 
 
 As a general rule the light should come from the left 
 side, and that position assumed or inclination given to the 
 instrument which is most comfortable to the observer. 
 
USE OP THE MICROSCOPE. 51 
 
 English and American microscopists prefer an inclined 
 microscope, while the German and French instruments 
 heing usually vertical do not permit this arrangement. 
 
 Adjustment. The details of microscopic adjustments 
 are only to be learned by practice, yet a few directions 
 may be instructive. The selection of the objectives and 
 eye-pieces depends on the character of the object. As a 
 general rule, the lowest powers which will exhibit an 
 object are the hest. It is best to use weak eye-pieces with 
 the stronger objectives, yet much depends on the perfec- 
 tion of the glasses employed. 
 
 The focal adjustment can be made with the coarse ad- 
 justment or quick motion when low powers are employed; 
 but for higher powers the tine adjustment screw is essen- 
 tial. Care must be taken not to bring the objective into 
 close or sudden contact with the thin glass cover over the 
 object, and, in changing object-glasses, the microscope 
 body should be raised from the stage by the coarse adjust- 
 ment. 
 
 The actual distance between the object and object-glass 
 is much less than the nominal focal length, so that the 
 1 inch objective has a working distance of about J an 
 inch, the Jth of about ^th of an inch, while shorter ob- 
 jectives require the object to be covered with the thinnest 
 glass. 
 
 Sometimes, in high powers, and especially ^th immer- 
 sion-lenses, an adjustment of the object-glass is necessary 
 in order to suit the thickness of the glass cover. With 
 thick covers the individual lenses must be brought nearer 
 to each other, and, with very thin covers, moved farther 
 apart. 
 
 If immersion-objectives be employed a drop of water is 
 placed on the glass cover with a glass rod or earners-hair 
 pencil, and a second drop on the lens. The lens and object 
 are then approximated till the drops flow together and the 
 focus is adjusted. By turning the screw of the objective 
 
52 THE MICROSCOPIST. 
 
 and using the fine adjustment the best position will be 
 shown by the sharper and more delicate image of the 
 object. 
 
 For other details respecting adjustment the reader is 
 referred to the chapter on Microscopic Accessories. 
 
 Errors of Interpretation. True science is hindered most 
 of all by speculation and false philosophy, which often 
 assume its garb and name, but it is also retarded by im- 
 perfect or false observation. It is much less easy to see 
 than beginners imagine, and still less easy to know what 
 we see. The latter sometimes requires an intellect of sur- 
 passing endowments. The sources of error are numerous, 
 but some require special caution, and to these we now 
 refer. 
 
 The nature of microscopic images causes error from 
 imperfect focal adjustment. We see distinctly only that 
 stratum of an object which lies directly in focus, and it is 
 seldom that all parts of an object can be in focus together. 
 Hence we only recognize at once the outline of an object, 
 but not its thickness, and, as the parts which are out of 
 focus are indistinct, we may readily fall into error. Glasses 
 vary much in this respect. Some have considerable pene- 
 trating and defining power even with moderate angular 
 aperture, and are better for general work than those more 
 perfect instruments which give paler images and only re- 
 veal their excellencies to the practiced microscopist. 
 
 Sometimes the focal adjustment leads to error on ac- 
 count of the reversal of the lights and shadows at differ- 
 ent distances. Thus the centres of the biconcave blood- 
 disks appear dark when in focus, and bright when a little 
 within the focus; while the hexagonal elevations of a dia- 
 tom, as the Pleurosigma angulatum^vQ light when in focus, 
 with dark partitions, and dark when just beyond the 
 focus. From this we gather a means of discrimination, 
 since a convex body appears lighter by raising the micro- 
 scope, and a concave by lowering it. 
 
USE OP THE MICROSCOPE. 53 
 
 The refractive power of the object, or of the medium in 
 which it lies, is sometimes a source of error. Thus a 
 human hair was long thought to be tubular, because of 
 the convergence of the rays of light on its cylindrical con- 
 vexity. A glass cylinder in balsam appears like a flat 
 band, because of the nearly equal refractive powers of 
 object and medium. The lacunae and canaliculse of bone 
 were long considered solid, because of the dark appear- 
 ance presented on account of the divergence of the rays 
 passing through them. Their penetration with Canada 
 balsam, however, proves them to be cavities. Air-bubbles, 
 from refraction, present dark rings, and, if present in a 
 specimen, seldom fail to attract the first attention of an 
 inexperienced observer. The difference between oil-globules 
 in water and water in oil, or air-bubbles, should be early 
 learned, as in some organized structures oil-particles and 
 vacuoles (or void spaces) are often interspersed. A globule 
 of oil in water becomes darker as the object-glass is de- 
 pressed, and lighter when raised ; while the reverse is the 
 case with water in oil, since the difference of refraction 
 causes the oil particles to act as convex lenses, and those 
 of water like concave lenses. 
 
 Other errors arise from the phenomena of motion visible 
 under the microscope. A dry filament of cotton, or other 
 fabric absorbing moisture, will often oscillate and twist 
 in a curious way. 
 
 If alcohol and water are mixed, the particles suspended 
 acquire a rapid motion from the currents set up, which 
 continues till the fluids are thoroughly blended. Xearly 
 all substances in a state of minute division exhibit, when 
 suspended in fluid, a movement called the " Brownonian 
 motion," from Dr. Robert Brown, who first investigated 
 it. It is a peculiar, uninterrupted, dancing movement, the 
 cause of which is still unexplained. These movements, 
 as all others, appear more energetic when greatly magni- 
 fied by strong objectives. It requires care to discriminate 
 
54 THE MICROSCOPIST. 
 
 between such motions and the vital or voluntary motions 
 of organized bodies. 
 
 O 
 
 The inflection or diffraction of light is another source 
 of error, since the sharpness of outline in an object is thus 
 impaired. The shadow of an opaque object in a divergent 
 pencil of light presents, not sharp, well-defined edges, but 
 a gradual shading off, from which it is inferred that the 
 rays do not pass from the edge of the object in the same 
 line as they come to it. This is in consequence of the 
 undulatory nature of light. When any system of waves 
 meets with an obstacle, subsidiary systems of waves will 
 be formed round the edge of the obstacle and be propagated 
 simultaneously with the original undulations. For a cer- 
 tain space around the lines in* which the rays, grazing the 
 edge of the opaque body, would have proceeded, the two 
 systems of undulation will intersect and produce the phe- 
 nomena of interference. If the opaque body be very small, 
 and the distance from the luminous point proportionally 
 large, the two pencils formed by inflection will intersect, 
 and all the phenomena of interference will become evident. 
 Thus, if the light be homogeneous, a bright line of light 
 will be formed under the centre of the opaque object, out- 
 side of which will be dark lines, and then bright and dark 
 lines alternately. If the light be compound solar light, a 
 series of colored fringes will be formed. In addition to 
 the results of inflection, oblique illumination at certain 
 angles produces a double image, or a kind of overlying 
 shadow, sometimes called the ''diffraction spectrum," 
 although due to a different cause. No rules can be given 
 for avoiding errors from these optical appearances, but 
 practice will enable one to overcome them, as it were, 
 instinctively. 
 
 Testing the Microscope. The defining power of an in- 
 strument depends on the correction of its spherical and 
 chromatic aberrations, and excellence may often be ob- 
 tained with objectives having but a moderate angle of 
 
USE OF THE MICROSCOPE. 55 
 
 aperture. It may be known by the sharp outline given 
 to the image of an object, which is not much impaired by 
 the use of stronger eye pieces. 
 
 Resolving power is the capability an instrument has of 
 bringing out the fine details of a structure, and depends 
 mainly on the angle of aperture of the objective, or the 
 angle formed by the focus and the extremities of the 
 diameter of the lens. On this account the increase of the 
 angle of aperture has been a chief aim with practical 
 opticians. 
 
 Penetrating power is the degree of distinctness with 
 which the parts of an object lying a little out of focus 
 may be seen. Objectives which have a large angle of 
 aperture, and in consequence great resolving power, are 
 often defective in penetration, their very perfection only 
 permitting accurate vision of what is actually in focus. 
 Hence for general purposes a moderate degree of angular 
 aperture is desirable. 
 
 Flatness of field of view is also a necessity for accurate 
 observation. Many inferior microscopes hide their im- 
 perfection in this respect by a contracted aperture in the 
 eye-piece, by which, of course, only a part of the rays 
 transmitted by the objective are available. 
 
 Object-glasses whose focal length is greater than half 
 an inch are called low powers. Medium powers range 
 from one-half to one-fifth of an inch focal length, and all 
 objectives less than one-fifth are considered high powers. 
 
 For definition with low power objectives, the pollen 
 grains of hollyhock, or the tongue of a fly, or a specimen 
 of injected animal tissue, will be a sufficient test. The 
 aperture should be enough to give a bright image, and 
 the definition sufficient for a clear image. A section of 
 wood, or of an echinus spine, will test the flatness of the 
 field. 
 
 Medium powers are seldom used with opaque objects 
 unless they are very small, but are most useful with 
 
56 THE MICROSCOPIST. 
 
 properly prepared transparent objects. A good half-inch 
 objective should show the transverse markings between 
 the longitudinal ribs on the scales of the Hipparehik 
 janira, butterfly (Plate I, Fig. 27), and the one-fourth or 
 one-fifth should exhibit markings like exclamation points 
 on the smaller scales of Podura plumbea (Plate I, Fig. 28) 
 or Lepidocyrtis. 
 
 High power objectives are chiefly used for the most 
 delicate and refined investigations of structure, and are 
 not so suitable for general work. It is with these glasses 
 that angular aperture is so necessary to bring out strise, 
 and dots, and other delicate structures, under oblique 
 illumination. For these glasses, the best tests are the 
 siliceous envelopes of diatoms, as the Pleiirosigma angu- 
 latum, Surirella gemma, Grammataphora subtilissima ; or 
 the wonderful plates of glass artificially ruled by M. Eg- 
 bert, and known as Robert's test. 
 
 The latter test is a series of lines in bands, the distance 
 between the lines decreasing in each band, until their 
 existence becomes a matter of faith rather than of sight, 
 since no glass has ever revealed the most difficult of them. 
 The test plate has nineteen bands, and their lines are 
 ruled at the following distances: Band 1, j-^^th of a 
 Paris line (to an English inch as .088 to 1.000, or as 11 to 
 125). Band 2, T ^th. Band 3, ^^th. Band 5, ^^th. 
 Band 9, 5 Vo th - Band 13 > Woo 1 * 1 - Band 17 > DUOO^- 
 Band 19, T oioT) tb - 
 
 It is said that Hartnack's immersion system No. 10 
 and oblique light has resolved the lines in the 15th band, 
 in which the distance of lines is about ^ T ooo^ n f an mcn - 
 
 The surface markings of minute diatoms are also ex- 
 cessively fine. Those of Pleiirosigma formosum. being from 
 20 to 32 in y^^th of an inch ; of P. hippocampus and P. 
 attenuation about 40 ; P. angulatum 46 to 52 ; Navicula 
 rhomboides 60 to 111 ; and Amphipleura pellucida 120 to 
 130. This latter has been variously estimated at 100,000 
 
PLATE I. 
 
 FIG. 28. 
 
 FIG. 27. 
 
 Scale of Hipparchia Janirn. 
 
 Scales of Podura plumbea:&, large 
 strongly marked scale; B, small scale 
 more faintly marked; c, portion of an 
 injured scale, showing the nature of the 
 markings. 
 
 FIG. 29. 
 
 n^r ^r ^ 
 * 
 
 w&w 
 
 Plevrosigma angiilatum : A, entire frustule, as seen 
 under a power of 500 diam. ; B, hexagonal aerolation, 
 as seen under a power of 1300 diam.; c, the same, 
 as seen under a power of 15,000 diam. 
 
USE OF THE MICROSCOPE. 
 
 57 
 
 to 130,000 in an inch. It has been resolved by Dr. Wood- 
 ward with the y'gth immersion of Powell and Lealand, 
 using oblique sunlight through a solution of ammonio- 
 sulphate of copper. 
 
 The longitudinal lines (between the transverse) of the 
 
 FIG. 30. 
 
 Valve of Surirella Gemma, 
 a. Transverse ridges. 6. Longitudinal lines, c. The same, resolved into areolations. 
 
 Surirella gemma are estimated at 30 to 32 in T J<jth of a 
 millimetre, and the markings on Grammataphora mbtilis- 
 sima at 32 to 34 in the same distance. 
 
 FIG. 31. 
 a. 
 
 Grammataphora Subtilissima. 
 a. Valve. 6. Transverse lines. 
 
 J. D. Moller has produced a very excellent test-plate, 
 containing twenty diatoms, with descriptions, according 
 to their value as tests. 
 
58 THE MICROSCOPIST. 
 
 The Pleurosigma angulatum (Plate I, Fig. 29), with suit- 
 able power and illumination, should show distinct hexag- 
 onal areolations. The Surirella gemma (Fig. 30) shows a 
 series of fine transverse lines across the ridges which run 
 from the edge to the central line. The finest of these 
 ridges are not always readily seen, and the transverse 
 ones are only to he mastered by toil and patience. 
 
 The Grammataphora subtilissima (Fig. 31) shows trans- 
 verse lines (or rows of dots) along the edge, and sometimes 
 a double series of oblique lines. 
 
 CHAPTER V. 
 
 MODERN METHODS OF EXAMINATION. 
 
 MICROSCOPY does not limit its researches to optical 
 enlargement, but seeks to comprehend elementary struc- 
 ture, and its methods vary according to the object imme- 
 diately in view. It may seek merely to discern the form 
 or morphology of the elementary parts or their peculiar 
 functions. It may be concerned with inorganic forms, 
 normal or pathological anatomy, or with physiology. 
 Each department of pursuit will suggest some variation, 
 yet a general plan of operation is possible. 
 
 Coarse, and moderately- large objects, as a small insect, 
 a piece of vegetable tissue, etc., may be observed by plac- 
 ing it in the forceps, or on the stage of the instrument, 
 under an objective of low power, but ordinarily a consid- 
 erable degree of preparation is needed in order to acquire 
 a true idea of structure. 
 
 Most of the tissues to be examined are in a moist con- 
 
MODERN METHODS OF EXAMINATION. 59 
 
 dition, and many require to be dissected or preserved in 
 fluid. This has much to do with the appearance of the 
 object in the microscope. If fibres or cells are imbedded 
 in connective tissue or in fluids, of which the refractive 
 power is the same as their own, they cannot be perceived 
 even with the best glasses, and artificial means must be 
 resorted to that they may become visible. The refractive 
 power of different media causes different appearances. 
 Thus a glass rod lying in water is easily seen, but in 
 Canada balsam, whose refractive power is nearly the same 
 as glass, it is barely seen as a flat band, and in the more 
 highly refractive anise oil it presents the appearance of a 
 cavity in the oil. 
 
 During life the cavities and fissures in animal tissues, 
 in consequence of the different refractive power of their 
 contents and the change which takes place soon after 
 death, exhibit a sharpness and softness of outline which 
 is seldom seen in preparations. 
 
 There are two methods of microscopic investigation or 
 of preparation preliminary to direct observation: 1. Me- 
 chanical, for the separation and isolation of the elemen- 
 tary parts. 2. Chemical, which dissolve the connecting 
 material, or act on it differently than on other elements. 
 
 For minute dissection a great variety of instruments 
 have been proposed, but by practiced hands more can be 
 accomplished in shorter time by simple means than with 
 complicated ones. Two or three scalpels, or small ana- 
 tomical knives, a pair of small scissors, such as is used in 
 operations on the eye, and fine-pointed forceps, will be 
 found useful. But the most serviceable instruments are 
 dissecting-needles, such as the microscopist may make for 
 himself. A common sewing-needle, with the eye end 
 thrust into a cedar stick about three inches long and one- 
 fourth of an inch diameter, will answer the purpose. The 
 point should not project so far as to spring, and if desired, 
 a cutting edge can be /given to it by a hone. 
 
60 
 
 THE MICROSCOPIST. 
 
 The light should be concentrated on the work by means 
 of a bull's-eye condenser, and as far as possible, the dis- 
 section should be carried on with the unassisted eye. 
 Very often the work is so fine that a magnifying glass, 
 or simple microscope, fixed to a suitable arm, will be 
 needed. A large Coddington lens, an inch and a half in 
 diameter, such as is used frequently by miners, will be 
 useful. Sometimes it is necessary to resort to the dissect- 
 ing microscope, which is a simple lens, of greater or less 
 power, arranged with rack and pinion, mirror, etc. 
 
 The specimen may be dissected under water, in a glass 
 or porcelain dish, or a trough made of gutta-percha, etc. 
 Dr. Lawson's binocular dissecting microscope (Fig. 32) is 
 
 FIG. 32. 
 
 Lawson's Binocular Dissecting Microscope. 
 
 a most useful form, as both eyes may be used. Loaded 
 corks, with sheet lead fastened to their under surface, 
 may be used to pin the subject on for greater facility in 
 dissection. Rests, or inclined planes of wood, one on each, 
 side of the trough, will give steadiness to the hands. 
 Camels'-hair pencils for the removal of dust and extrane- 
 
MODERN METHODS OF EXAMINATION. 61 
 
 ous elements, and for spreading out thin and delicate tis- 
 sues or sections, are indispensable. Pipettes, or glass 
 tubes, one end of which can be covered with the end of 
 the finger, may serve to convey a drop of fluid or a small 
 specimen from a bottle. 
 
 Preparation of Loose Textures. If the formed elements 
 of tissue do not combine in a solid mass, it is only neces- 
 sary to place a small quantity on a glass slide and cover 
 it with a plate of thin glass. If the elements are too close 
 for clear definition under the microscope, a drop of fluid 
 may be added. The nature of this fluid, however, is not 
 a matter of indiiference. Some elements are greatly 
 changed by water, etc., and it becomes important to con- 
 sider the fluid which is most indifferent. Glycerin and 
 water, one part to nine of water, will serve well for most 
 objects. Animal tissues are often best treated with aque- 
 ous hurnor, serum, or iodized serum. A weak solution of 
 salt, 7.5 grains chloride of sodium to 1000 grains of dis- 
 tilled water, serves for many delicate structures. (See 
 section on Fluid Media.) 
 
 Preparation by Teasing. A minute fragment of tissue 
 should be placed in a drop of fluid on a slide, and torn or 
 unravelled by two sharp needles. This is accomplished 
 more easily after maceration, and sometimes it is neces- 
 sary to macerate in a substance which will dissolve the 
 connecting material. This picking or teasing should be 
 slowly and accurately performed. Beginners often fail 
 of a good preparation by ceasing too soon, as well as by 
 having too large a specimen. The most delicate manipu- 
 lation is required to isolate nerve-cells and processes. 
 
 Preparation by Section. A section of soft substance may 
 be made with a sharp knife or scalpel, or with a pair of 
 scissors curved on the upper side. A section cut with the 
 latter will taper away at the edges so as to afford a view 
 of its structure. 
 
62 THE MICROSCOPIST. 
 
 Valentin's double knife (Fig. 33) is used for soft tissues 
 where only a moderate degree of thinness is needed. The 
 blades should be wet, or the section made under water. 
 
 Soft substances often require hardening before sections 
 can be made. The most simple and best method is that 
 of freezing, by surrounding the specimen with a freezing 
 mixture, when it may be cut with a cold knife. Small 
 pieces of tissue may be hardened in absolute alcohol, fre- 
 quently renewed. Chromic acid, in solution of one-fourth 
 to two per cent., is often used for animal tissues, or bichro- 
 mate of potash of the same strength. A solution of one- 
 fifth to one-tenth per cent, of perosmic acid or of chloride 
 of palladium is also recommended. 
 
 Soft tissues often require imbedding in a concentrated 
 solution of gum or of wax, spermaceti, or paraffin tem- 
 pered with oil. In this case sections may be made readily 
 by means of a section-cutter. For imbedding in wax, etc., 
 
 FIG. 33. 
 
 Valentin's Knife. 
 
 the specimen must be hardened in alcohol, then treated 
 with oil of cloves or turpentine, and the section should be 
 mounted in Canada balsam or Dammar varnish. 
 
 Sections of hard substances, or of those imbedded, are 
 often made by machines invented for the purpose. One 
 of the simplest is (Fig. 34) an upright hollow cylinder, 
 with a kind of piston, pushed upwards by a fine screw. 
 The upper end of the cylinder carrying the specimen ter- 
 minates in a flat table, along which a sharp knife or flat 
 razor is made to slide. At one side of the tube is a 
 binding-screw for holding the specimen steady. A sec- 
 
MODERN METHODS OF EXAMINATION. 63 
 
 tion may be cut by such an instrument after inserting 
 the structure desired in a piece of carrot, etc., which may 
 be placed in the tube ; or the tube may be filled with wax, 
 etc., and the specimen imbedded. Bones, teeth, shells, 
 corals, minerals, etc., require to be cut with fine saws, or 
 a disk of thin iron on a lapidary's wheel, and filed or 
 ground down to the requisite thinness, then polished with 
 emery, rouge, etc. The green oxide of chromium has 
 been suggested to me as a useful polishing powder for 
 hard substances. For calcareous substances, files and 
 hones will suffice to reduce the thickness, and putty 
 
 FIG. 34. 
 
 Section-Cutter. 
 
 powder or jewellers' rouge for polishing. They should 
 be mounted in Canada balsam. 
 
 Staining Tissues. Certain elements, not previously visi- 
 ble, can often be made evident by certain coloring matters, 
 by which some constituents become more quickly or more 
 thoroughly stained than others. The " germinal matter," 
 or " bioplasm " of Dr. Beale, identical with the " proto- 
 plasm " or " sarcode " of other observers, may thus be dis- 
 tinguished from the " formed materials " or " tissue ele- 
 
64 
 
 THE MICROSCOPIST. 
 
 ment," which are the products of its activity. Carmine, 
 auilin, hsematoxylin, and picric acid, are used for staining 
 by imparting their own color to tissues ; while nitrate of 
 silver, chloride of gold, chloride of palladium, and peros- 
 mic acid stain, by their chemical action, often under the 
 reducing influence of light. (See Fluid Media.) 
 
 Injecting Tissues. Injections of the vessels in animal 
 tissues are resorted to either to exhibit their course or the 
 structure of the vascular walls. For the latter purpose a 
 solution of nitrate of silver is commonly employed, for the 
 former either opaque or transparent coloring matter. (See 
 Fluid Media.} 
 
 The injecting syringe (Fig. 35) is made of brass or Ger- 
 
 FlG. 35. 
 
 Injecting Syringe. 
 
 man silver. One of the pipes should be inserted into the 
 principal vessel, as the aorta of a small animal, the um- 
 bilical vein of a foetus, or the artery, etc , of an organ, 
 and should be securely fastened by a thread. All other 
 open vessels should be tied. The solution of gelatin, or 
 other matter used, should be strained, so as to be free 
 from foreign particles, and should be forced into the ves- 
 sels with a gentle, steady pressure on the syringe. 
 
 Injections should be made soon after the death of the 
 animal, or else after the rigor mortis has subsided. 
 
MODERN METHODS OF EXAMINATION. 65 
 
 Sometimes the syringe is substituted by a self-acting 
 apparatus, consisting of a Wolfe's bottle, containing the 
 fluid, which is pressed upon by a column of air from 
 another source, and driven through a flexible tube to the 
 pipe in the bloodvessel. 
 
 The older anatomists used colored plaster or wax to 
 demonstrate the arteries and veins, but modern histology 
 requires finer materials. Isinglass or gelatin, colored, and 
 injected warm, or a solution of colored glycerin, are now 
 resorted to. The former serves for opaque, and the latter 
 for fine, transparent injections. 
 
 The art of injecting can only be learned by practice, 
 yet perseverance, in despite of many failures, will insure 
 success. 
 
 The liver, kidney, etc., may be injected separately, and 
 it is often desirable to use various colors for the different 
 sets of vessels. After injection thin slices may be cut off 
 and mounted in fluid or balsam. 
 
 Preparation in Viscid Media. Dr. Beale has proposed a 
 method of preparing animal and vegetable tissues for ex- 
 amination with the very highest powers, which has led to 
 valuable results. It consists in using pure glycerin or 
 strong syrup, instead of watery solutions. In this way 
 an amount of pressure may be applied to sections, in order 
 to render them thin enough for examination, which would 
 be destructive to specimens in water, while the preserva- 
 tive action of the media prevents change in the structure. 
 It is necessary to soak the specimen some time, and the 
 strength of the fluid should be gradually increased until 
 the tissue is permeated by the strongest that can be ob- 
 tained. Dr. Beale has found that minute dissection is 
 much more readily performed in such fluids, and that 
 even very hard textures, as bone and teeth, may be softened 
 by them, especially if acetic acid is added, so as to permit 
 thin sections to be made with a knife. He recommends 
 
 5 
 
66 THE MICROSCOPIST. 
 
 vessels to be first injected, as with fine, transparent blue, 
 and the germinal matter to be stained with carmine. A 
 few drops of a solution of chromic acid, or bichromate of 
 potash, so as to impart to the glycerin a pale straw color, 
 serves to harden even the finest nerve-structures. Acetic 
 acid, and other reagents also, are much more satisfactorily 
 used with glycerin than with water. If syrup is used, 
 camphor, carbolic acid, etc , must be employed to prevent 
 the growth of fungi, but pure glycerin is free from this 
 inconvenience. 
 
 A great advantage of this mode of investigation con- 
 sists in the fact that a specimen thus prepared is already 
 mounted, and needs but a proper cement to the glass cover 
 and a finish to the slide, when it is ready for'the cabinet. 
 
 FLUID MEDIA. 
 
 1. INDIFFERENT FLUIDS. 
 
 The vitreous humor, amniotic liquor, serum, etc., which 
 form the usual fluids termed indifferent, always contain 
 what Prof. Graham designated colloid and crystalloid 
 substances. In 1000 parts there are about 4 parts of col- 
 loid (albumen) and 7.5 of crystalloid substance (chloride 
 of sodium). 
 
 The iodine serum of Schultze consists of the amniotic 
 fluid of the embryo of a ruminant, to which about 6 drops 
 of tincture of iodine to the ounce is added A small piece 
 of camphor will preserve this from decomposition a long 
 time. A substitute for this is composed of 1 ounce of 
 white of egg, 9 ounces of water, 2 scruples chloride of 
 sodium, with the corresponding quantity of tincture of 
 iodine. 
 
MODERN METHODS OF EXAMINATION. 67 
 
 2. CHEMICAL REAGENTS. 
 
 The greatest care should be used with these, that the 
 instrument and glasses may be preserved. A small drop, 
 applied by a glass rod drawn out to a point to the edge of 
 the glass cover, will suffice in most cases. 
 
 Sulphuric Add. Concentrated is used to isolate the 
 cells of horny structures, as hair, nails, etc. Dilute (1 part 
 to 2-3 of water) gives to cellulose, previously dyed with 
 iodine, a blue or purple color, and, when mixed with 
 sugar, a rose-red to nitrogenous substances and bile. 0.1 
 to 1000 of water, at a temperature of 35-40 C., resolves 
 connective tissue into gelatin and dissolves it, so as to be 
 useful in isolating muscular fibres. 
 
 Nitric Acid. Diluted with 4 or 5 parts water, separates 
 the elementary parts of many vegetable and animal tis- 
 sues when they are boiled or macerated in it. With chlo- 
 rate of potash it is still more energetic, but caution is 
 needed in its use. 
 
 Muriatic Acid, Strong. Used for dissolving intercellular 
 substance, as in the tubes of the kidney, etc. Dilute for 
 dissolving calcareous matter. 
 
 Chromic acid, J to 2 per cent, solution for hardening 
 nerves, brain, etc. 
 
 Oxalic add, to 15 parts water, causes connective tissue 
 to swell and become transparent, while albuminoid ele- 
 ments are hardened. Preserves well delicate substances, 
 as rods of retina, etc. 
 
 Acetic acid makes nuclei visible and connective tissue 
 transparent, so as to exhibit muscles, nerves, etc., other- 
 wise invisible. 
 
 Iodine (1 grain of iodine, 3 grains iodide of potassium, 
 1 ounce of water) turns starch blue and cellulose brown. 
 
 Caustic potash or soda renders many structures trans- 
 parent. 
 
68 THE MICROSCOPIST. 
 
 Lime-water or baryta-water is used for investigating con- 
 nective structures, especially tendon, as maceration en- 
 ables the needle to divide its fibril] a. 
 
 Chloride of Sodium. Solutions of this salt for indifferent 
 media should always have some colloid, as albumen or 
 gum-arabic added (7.5 grains in 1000 grains of water for 
 delicate structures). 
 
 Bichromate of potash is used in stronger solution for the 
 same purposes as chromic acid. 
 
 Mutter's eye-fluid for hardening the retina, and preserv- 
 ing delicate embryos, etc., consists of bichromate of potass,, 
 2 grammes ; sulphate of soda, 1 gramme ; distilled water, 
 100 grammes. 
 
 Alcohol dissolves resins and many vegetable coloring 
 matters ; renders most vegetable preparations more trans- 
 parent, and albuminous animal tissues more opaque. 
 
 Acetic acid and alcohol, 1 part of each to 2 of water, 
 renders connective tissue transparent, and albuminoid tis- 
 sue prominent. The proportions can be varied. 
 
 Alcohol and soda (8-10 drops of strong solution of caustic 
 soda to each ounce) renders many tissues very hard and 
 transparent. Beale recommends it for embryonic struc- 
 tures. 
 
 Ether dissolves resins, oils, and fat. 
 
 Turpentine renders dried animal sections transparent. 
 
 Oil of cloves acts as turpentine. 
 
 Solution of chloride of zinc, iodine, and iodide of potassium, 
 is recommended by Schacht as a substitute for iodine and 
 sulphuric acid to color vegetable cells, etc. Zinc is dis- 
 solved in hydrochloric acid, and the solution is evaporated 
 to syrupy consistence in contact with metallic zinc. This 
 is saturated with iodide of potassium, iodine added, and 
 the solution diluted with water. Wood cells, after boiling 
 in caustic potash, are stained blue by it. 
 
 Boracic acid, used by Prof. Brucke to separate the ele- 
 ments of red blood-corpuscles. 
 
MODERN METHODS OF EXAMINATION. 69" 
 
 3. STAINING FLUIDS. 
 Thier setts Carmine Fluids. 
 
 a. RED FLUID. 
 
 1. Carmine, 1 part. 
 
 Caustic ammonia, . . . . 1 " 
 
 Distilled water, 3 parts. Filter. 
 
 2. Oxalic acid, 1 part. 
 
 Distilled water, ...... 22 parts. 
 
 1 part of carmine solution to 8 parts of the acid solution, add 12 parts 
 absolute alcohol. Filter. After staining wash in 80 per cent, alcohol. 
 
 b. LILAC FLUID. 
 
 Borax, 4 parts. 
 
 Distilled water, 56 ' 
 
 Dissolve and add, 
 
 Carmine, .1 part. 
 
 Mix with twice the volume of absolute alcohol and filter. 
 
 Beetle's Carmine Fluids. 
 
 Carmine, 10 grains. 
 
 Strong liquor ammonia, drachm. 
 
 Glycerin, 2 ounces. 
 
 Distilled water, 2 " 
 
 Alcohol, ....... ounce. 
 
 Dissolve the carmine in the ammonia in a test-tube by aid of heat ; boil 
 it and cool and add the other ingredients. Filter. 
 
 Acid Carmine Fluid. Mix ammoniacal solution of car- 
 mine with acetic acid in excess and filter. This is said 
 to stain diffusely, but adding glycerin with muriatic acid 
 (1 : 200), concentrates the color in the cell-nucleus. 
 
 Anilin (or Magenta) Red Fluid. 
 
 Fuchsin (crystal), ..... 1 centigramme. 
 Absolute alcohol, .... 20-25 drops. 
 Distilled water, 15 cubic centim. 
 
 Anilin Blue Fluid. Anilin blue, treated with sulphuric 
 acid and dissolved in water till a deep cobalt color is 
 obtained. 
 
70 THE MICROSCOPIST. 
 
 Blue Fluid from Indigo Carmine. 
 
 Oxalic acid, 1 part. 
 
 Distilled water, 20-30 parts. 
 
 Indigo carmine to saturation. 
 
 Logwood Violet Fluid. 
 
 1. Haematoxylin, . . . . . .20 grains. 
 
 Absolute alcohol, ounce. 
 
 2. Solution of 2 grains of alum to 1 ounce of water. 
 
 A few drops of the first solution to a little of the second in a watch- 
 glass, etc. 
 
 Picro-Carmine Fluid. Filter a saturated solution of 
 picric acid, and add, drop by drop, strong ammoniacal 
 solution of carmine till neutralized. 
 
 Nitrate of Silver Fluid. Fresh membranous tissues, 
 exposed to 0.5 to 0.2 per cent, solution of nitrate of silver, 
 washed and exposed to light, often show a mosaic of epi- 
 thelium, etc. 
 
 Osmic Acid. y^th to 1 per cent, solution stains the 
 medulla of nerves, etc., black. 
 
 Chloride of Gold. The solution should be similar to that 
 of nitrate of silver. Exposure to light stains the nerves, 
 etc., a violet or red color. 
 
 Prussian Blue. After immersing a tissue in 0.5 to 1 
 per cent, solution of a protosalt of iron, dip it in a 1 per 
 cent, solution of ferrocyanide of potassium. 
 
 Other Staining Fluids. Marked effects are often pro- 
 duced by the use of the violet, blue, and other inks in the 
 market. Thus I succeeded in some demonstrations of 
 nerve plexuses in muscle better than in any other way. 
 I suspect the particular ink employed contained a large 
 per cent, of soluble Prussian blue. 
 
 4. INJECTING FLUIDS. 
 
 For opaque injection several plans have been devised. 
 Resinous and gelatinous substances, variously colored, are 
 
MODERN METHODS OF EXAMINATION. 71 
 
 most usual. Lieberkuhn used tallow, varnish, and tur- 
 pentine, colored with cinnabar ; and Hyrtl, whose prepa- 
 rations have been much admired, follows a similar plan. 
 He evaporates pure copal or mastic varnish to the consis- 
 tence of syrup, and grinds one-eighth as much cinnabar 
 and a little wax with it on a slab. For fine injections this 
 is diluted with ether. 
 
 For a bright red, the cinnabar may be mixed with a 
 little carmine. 
 
 For a yellow color, the chromate of lead, prepared by 
 mixing solutions of acetate of lead (36 parts to 2 ounces 
 of water), and red chromate of potash (15 parts). 
 
 White may be made with zinc-white or carbonate of 
 lead ij ounces of acetate of lead in 16 ounces of water, 
 mixed with 3J ounces carbonate of soda in 16 ounces. 
 
 For gelatinous injections the coloring matter is com- 
 bined with jelly, prepared by soaking fine gelatin in cold 
 water for several hours, then dissolving in a water-bath 
 and filtering through flannel. 
 
 By injecting gelatinous fluid solutions of various salts, 
 the coloring matter may be left in the vessels by double 
 decomposition. 
 
 A red precipitate, with iodide of potassium and bichlo- 
 ride of mercury. 
 
 A blue, by ferrocyanide of potassium and peroxide of 
 iron, etc. 
 
 Dr. Goadby's formula for a yellow color is : 
 
 Saturated solution of bichromate of potassium, . 8 ounces. 
 
 Water, 8 " 
 
 Gelatin, 2 " 
 
 Saturated solution of acetate of lead, . . .8 ounces. 
 
 Water, 8 " 
 
 Gelatin, 2 " 
 
 For gelatinous injections, both the fluid and the subject 
 should be as warm as may consist with convenience. 
 Camphor also should be added to prevent mould. 
 
72 THE MICROSCOPIST. 
 
 For transparent injections, gelatin may be used combined 
 with colored solutions, or still better, glycerin, which may 
 be used cold. 
 
 Thiersch's Blue. Half an ounce of warm concentrated 
 solution (2:1) of fine gelatin is mixed with 6 cubic centim- 
 etres of a saturated solution of sulphate of iron. In 
 another vessel, 1 ounce of the gelatin solution is mixed 
 with 12 cubic centimetres of saturated solution of ferro- 
 cyanide of potassium, to which 12 cubic centimetres of 
 saturated solution of oxalic acid is added. When cold, 
 add the gelatinous solution of sulphate of iron drop by 
 drop, with constant stirring, to the other. Warm it, 
 still stirring, and filter through flannel. 
 
 Gerlach's Carmine. Dissolve 5 grammes (77 grains) of 
 fine carmine in 4 grammes (70 grains) of water and J 
 gramme (8 drops) of liquor ammonia. Let it stand sev- 
 eral days (not airtight), and mix with a solution of 6 
 grammes of fine gelatin to 8 grammes of water, to which 
 a few drops of acetic acid are added. 
 
 Thiersctis Yellow. Prepare a solution of chromate of 
 potash (1 : 11), and a second solution of nitrate of lead, of 
 same strength. To 1 part of the first add 4 parts of solu- 
 tion of gelatin (about 20 cubic centimetres to 80), and to 
 2 parts of the second add 4 parts of gelatin (40 cubic cen- 
 timetres to 80). Mix slowly and carefully, heat on a 
 water-bath, and filter through flannel. 
 
 Equal parts of Thiersch's blue and yellow carefully 
 mixed and filtered make a good green. 
 
 COLD TRANSPARENT INJECTIONS. 
 
 Beale's Blue. 
 
 Glycerin, 1 ounce. 
 
 Alcohol, 1 " 
 
 Ferrocyanide of potassium, .... 12 grains. 
 Tincture of perchloride of iron, . . . 1 drachm. 
 
 Water, 4 ounces. 
 
MODERN METHODS OF EXAMINATION. 73 
 
 Dissolve the ferrocyanide in 1 ounce of water and glyc- 
 erin, and the muriated tincture of iron in another ounce. 
 Add the latter very gradually to the other, shaking often ; 
 then gradually add the alcohol and water. 
 
 Beetle's Finest Blue. 
 
 Price's glycerin, 2 ounces. 
 
 Tincture of perchloride of iron, . . .10 drops. 
 Ferrocyanide of potassium, .... 3 grains. 
 Strong hydrochloric acid, ..... 3 drops. 
 Water, 1 ounce. 
 
 Mix the tincture of iron with 1 ounce glycerin and the 
 ferrocyanide, after dissolving in a little water, with the 
 other ounce. Add the iron to the other solution gradu- 
 ally, shaking well. Lastly, add the water and hydro- 
 chloric acid. Sometimes about 2 drachms of alcohol are 
 added. 
 
 Miiller's Blue. This is made by precipitation of soluble 
 Prussian blue from a concentrated solution by means of 
 90 per cent, alcohol. 
 
 Beetle's Carmine. Mix 5 grains of carmine with a few 
 drops of water, and when well incorporated, add 5 or 6 
 drops of liquor ammonia. To this add J ounce of glyc- 
 erin, and shake well. Another J ounce of glycerin con- 
 taining 8 or 10 drops of acetic or hydrochloric acid is 
 gradually added. It is then diluted with J ounce of glyc- 
 erin, 2 drachms of alcohol, and 6 drachms of water. 
 
 Nitrate of Silver Injection. For demonstrating the struc- 
 ture of the bloodvessels, the animal is bled, and a solution 
 of 0.25 to 1 per cent, of nitrate of silver, or a mixture of 
 gelatin with such a solution, is used. 
 
 5. PRESERVATIVE FLUIDS. 
 
 Canada Balsam. This is perhaps the most common 
 medium used. When an object is not very transparent, 
 and drying will not injure it, balsam will do very well, 
 
74 THE MICROSCOPIST. 
 
 but it is not adapted to moist preparations. Colonel 
 Woodward, of "Washington, uses a solution of dried or 
 evaporated Canada balsam in chloroform or benzole. 
 
 Dammar Varnish. Dr. Klein and other German his- 
 tologists prefers this to Canada balsam. Dissolve J to 1 
 ounce of gum Dammar in 1 ounce of turpentine ; also J 
 to 1 ounce of mastic in 2 ounces of chloroform. Mix and 
 filter. 
 
 Glycerin. This fluid is universally useful to the micros- 
 copist. (See Preparation in Viscid Media, page 65.) Vege- 
 table and animal substances may be preserved in glycerin, 
 but if it is diluted, camphor or creasote must be added 
 to prevent confervoid growths. It is said, however, to 
 dissolve carbonate of lime. 
 
 Gelatin and Glycerin. Soak gelatin in cold water till 
 soft, then melt in warm water, and add an equal quantity 
 of gly cerin. 
 
 Gum and Glycerin. Dissolve 1J grains of arsenious 
 acid in 1 ounce of water, then 1 ounce of pure gum arabic 
 (without heat), and add 1 ounce of glycerin. 
 
 Deane's Compound. Soak 1 ounce of gelatin in 5 ounces 
 of water till soft ; add 5 ounces of honey at a boiling heat. 
 Boil the mixture, and when cool, add t> drops of creasote 
 in J ounce of alcohol; filter through flannel. To be used 
 warm. 
 
 Carbolic Acid. 1 : 100 of water is a good preservative. 
 
 Thwaite's Fluid. To 16 parts of distilled water, add 1 
 part of rectified spirit and a few drops of creasote ; stir in 
 a little prepared chalk, and filter. Mix an equal measure 
 of camphor-water, and strain before using. For preserva- 
 tion of algae. 
 
 Solution of Naphtha and Creasote. Mix 3 drachms of 
 creasote with 6 ounces of wood naphtha ; make a thick, 
 smooth paste with prepared chalk, and add gradually, 
 rubbing in a mortar, 64 ounces of water. Add a few 
 lumps of camphor, and let it stand several weeks before 
 
MODERN METHODS OF EXAMINATION. 75 
 
 pouring off or filtering the clear fluid. Dr. Beale recom- 
 mends this highly for the preservation of dissections of 
 nerves and morbid specimens. 
 
 Ealfs Fluid. As a substitute for Thwaite's fluid in 
 the preservation of algse. 1 grain of alum and 1 of bay 
 salt to 1 ounce of distilled water. 
 
 Goadby's Solution. Bay salt, 4 ounces ; alum, 2 ounces ; 
 corrosive sublimate, 4 grains; boiling water, 4 pints. 
 This is the strength most generally useful, although it 
 may be made stronger or more dilute. It is a useful 
 fluid. If the specimen contain carbonate of lime, the 
 alum must be left out, and the quantity of salt may be 
 quadrupled. 
 
 Dr. Beale discards all solutions containing salts for 
 microscopic purposes, as they render the textures opaque 
 and granular. 
 
 Soluble Glass, or a solution of silicate of soda or potash, 
 or of both, has been proposed, but it is apt to render 
 specimens opaque. 
 
 Chloride of Calcium in saturated aqueous solution has 
 been much recommended, especially by botanists. 
 
 Acetate of Potash, a nearly saturated solution, is useful 
 for vegetable preparations and for specimens of animal 
 tissue which have been stained with osmic acid. The 
 latter do not bear glycerin. 
 
 Pacinian Fluid. This is variously modified, but may 
 consist of corrosive sublimate, 1 part ; chloride of sodium, 
 2 parts; glycerin, 13 parts; distilled water, 113 parts. 
 Sometimes acetic acid is substituted for chloride of so- 
 dium. 
 
 6. CEMENTS. 
 
 Gold Size is recommended by Dr. Carpenter as most 
 generally useful for thin covers. It is made by boiling 
 25 parts of linseed oil for three hours with 1 part of red 
 lead and J of as much umber. The fluid part is then 
 mixed with yellow ochre and white lead in equal parts, 
 
76 THE MICROSCOPIST. 
 
 so as to thicken it, the whole boiled again, and the fluid 
 poured off for use. 
 
 Bell's Cement is said to be best for gtycerin specimens. 
 It appears to be shellac dissolved in strong alcohol. 
 
 Brunswick Black is asphaltura dissolved in turpentine. 
 A little india-rubber dissolved in mineral naphtha is some- 
 times added. 
 
 Canada Balsam in chloroform or Dammar varnish (page 
 74) is often used as a cement. 
 
 Marine Glue. This is most useful in building glass 
 cells, etc. It consists of equal parts of shellac and india- 
 rubber dissolved in mineral naphtha by means of heat. 
 
 Electrical Cement is made by melting together 5 parts 
 of 'rosin, 1 of beeswax, and 1 of red ochre. 2 parts of 
 Canada balsam added make it more adhesive to glass. 
 
 White, hard Varnish, or gum sandarac, dissolved in 
 alcohol and mixed with turpentine varnish, is sometimes 
 colored by lampblack, sealing-wax, etc. 
 
 White Zinc Cement. Oxide of zinc rubbed up with 
 equal parts of oil of turpentine and 8 parts of solution of 
 gum Dammar in turpentine of a syrupy consistence, or 
 Canada balsam, chloroform, and oxide of zinc. 
 
 CHAPTER VI. 
 
 MOUNTING AND PRESERVING OBJECTS FOR THE MICROSCOPE. 
 
 FOR the permanent preservation of specimens, various 
 means are employed, according to the nature of the object 
 and the particular line of investigation desired. Few, if 
 any, objects show all their peculiarities of structure or 
 adaptation to function, and for scientific work it is often 
 
MOUNTING AND PRESERVING OBJECTS. 77 
 
 necessary to have the same structure prepared in different 
 ways. 
 
 Opaque Objects have sometimes been attached by thick 
 gum to small disks of paper, etc , or to the bottom and 
 sides of small pill-boxes, or in cavities in slides of bone or 
 wood, but they are better preserved on glass slides, as 
 hereafter described. 
 
 The most convenient form of slide for microscopic pur- 
 poses is made of flattened crown or flint glass, cut into 
 slips of three inches by one inch, and ground at the edges. 
 Some preparations are mounted on smaller slips, but they 
 are less convenient than the above, which is regarded as 
 the standard size. 
 
 On such slides objects are fixed, and covered by a square 
 or round piece of thin glass, varying from o'oth to oio tn 
 of an inch in thickness. Both slides and thin glass can 
 be procured at opticians' stores. Laminae of mica or talc 
 are sometimes used for lack of better material, but are too 
 soft. For object-glasses of the shortest focal length, how- 
 ever, it is necessary at times to resort to this sort of cov- 
 ering. 
 
 Great care should be taken to have both slide and cover 
 clean. With thin glass this is difficult, owing to its brit- 
 tleness. Practice will teach much, but for the thinnest 
 glass two flat pieces of wood covered with chamois leather, 
 between which the cover may lie flat as it is rubbed, will 
 be serviceable. 
 
 Very thin specimens may be mounted in balsam, glyc- 
 erin, etc., covered with the thin glass cover, and then 
 secured by a careful application of cement to the edges of 
 the cover. If, however, the pressure of the thin glass be 
 objectionable, or the object be of moderate thickness, some 
 sort of cell should be constructed on the slide. 
 
 The thinnest cells are made with cement, as gold size, 
 Brunswick black, etc., painted on with a camel's-hair pen- 
 cil. For preparing these with elegance, Shadbolt's turn- 
 
78 
 
 THE MICROSCOPIST. 
 
 table has been contrived (Fig. 36). The slide is placed 
 between the springs, and while rotated, a ring of varnish 
 of suitable breadth is made on the glass. 
 
 A piece of thin glass (or even of thick glass) may be 
 perforated and cemented to the slide with marine glue by 
 
 FIG. 36. 
 
 Shadbolt's Turntable for making Cement-Cells. 
 
 the aid of heat; or vulcanite, lead, tin, gutta percha, etc., 
 may be made into a cell in a similar way as seen in Fig. 
 37. 
 
 The perforation of thin glass may be easily performed 
 by cementing it over a hole in a brass plate, etc., with 
 marine glue, and punching it through with the end of a 
 
 FIG. 37. 
 
 Cell of Glass, Vulcanite, etc. 
 
 file. The edges may then be filed to the size of the hole, 
 and the glass removed by heating the brass. Thicker 
 glass may be bored with a file by moistening it with 
 turpentine. 
 
 Dry objects, especially if they are transparent, as dia- 
 toms, thin sections of bone, crystals, etc., may be attached 
 to the slide with Canada balsam, etc., covered with thin 
 
MOUNTING AND PRESERVING OBJECTS. 79 
 
 glass, which should be cemented at the edges, and gummed 
 over all a strip of colored or lithographed paper, in which 
 an aperture has been made with a punch. 
 
 Mounting in Balsam or Dammar Varnish is suitable for 
 a very large proportion of objects. It increases the trans- 
 parency of many structures, tilling up interstices and cavi- 
 ties, and giving them a smooth, beautiful appearance. 
 Very delicate tissues, as fine nerves, etc., are rendered in- 
 visible by it, and require other fluids, as glycerin. 
 
 Before mounting in balsam, the object should be thor- 
 oughly dry, otherwise a milky appearance will result. It 
 should then be placed in oil of cloves or of turpentine to 
 remove greasiuess and increase the transparency. A clean 
 slide, warmed over a spirit-lamp or on a hot plate, should 
 then have a little balsam placed on its centre, and the 
 object carefully lifted from the turpentine is put into the 
 balsam and covered with another drop. The slide should 
 then be gently warmed, and any air-bubbles pricked with 
 a needle-point or drawn aside. The thin glass cover should 
 be warmed and put on gently, in such a way as to lean 
 first on one edge and fall gradually to a horizontal posi- 
 tion. The slide may be warmed again, and the superflu- 
 ous balsam pressed from under the cover by the pressure 
 of a clean point upon it. 
 
 If the object is full of large air-spaces and is not likely 
 to be injured by heat, the air may be expelled by gently 
 boiling it in the balsam on the slide. If the object be one 
 which will curl up, or is otherwise injured by heat, the 
 air-pump must be resorted to. A cheap substitute for the 
 air-pump may be made by fitting a piston into a tolerably 
 wide glass tube closed at one end. The piston should 
 have a valve opening outwards. The preparation in bal- 
 sam may be placed at the bottom of the tube, and a few 
 strokes of the piston will exhaust the air. 
 
 To fill a deep cell with Canada balsam, it may be well 
 to fill it first with turpentine and place the specimen in 
 
80 THE MICROSCOPIST. 
 
 it. Then pour in the halsam at one end, the slide being 
 inclined so that the turpentine may run out at the other. 
 Lay the cover on one edge of the cell and gradually lower 
 it till it lies flat. In this way air may be excluded. 
 
 The solution of balsam in chloroform needs no heat, 
 and has little liability of air-bubbles. 
 
 The excess of balsam round the edge of the glass cover 
 may be removed with a knife and cleaned with turpentine 
 or benzine, etc. 
 
 For animal tissues, the oil of cloves is sometimes used 
 instead of turpentine to increase the transparency, and a 
 wet preparation, as a stained or injected specimen, may 
 be mounted in balsam or Dammar by first placing it in 
 absolute alcohol to extract the water, then transferring 
 to oil of cloves or turpentine, and lastly, to the balsam. 
 In a reverse order, a specimen from balsam may be cleaned 
 and mounted in fluid. 
 
 Mounting in Fluid is necessary for the preservation of 
 the most delicate tissues and such as may be injured by 
 
 Spring Clip. 
 
 drying. Glycerin is perhaps the most generally useful 
 fluid. (See Preservative Fluids, page 73.) 
 
 For mounting in fluid, it is safer to have a thin cell of 
 varnish prepared first than to risk the running in of the 
 cement under the cover, as will be likely to occur other- 
 wise. 
 
 The air-pump is sometimes needed in mounting in fluid 
 to get rid of air-bubbles, A spring clip (Fig. 38) is also 
 
MOUNTING AND PRESERVING OBJECTS. 81 
 
 a useful instrument for making moderate pressure on the 
 glass cover until the cement on its edge is dry. A drop- 
 ping-tube with a bulbous funnel, covered with thin india- 
 rubber, for taking up and dropping small quantities of 
 fluid, will also be of service. 
 
 Superfluous fluid may be removed from the edge of the 
 cover by a piece of blotting-paper, care being used not to 
 draw away the fluid beneath the cover. 
 
 As soon as objects are mounted, the slides should be 
 labelled before cementing is finished, otherwise time will 
 be lost in searching for a particular object among others, 
 or the name may be forgotten. 
 
 Boxes of wood or of pasteboard, with grooved racks at 
 the sides, are occasionally used for preserving a collection 
 of specimens. It is better, however, to have a cabinet 
 with drawers or trays so that the specimens may lie flat, 
 with their ends towards the front of the drawer. A piece 
 of porcelain on the end of the drawer is convenient for 
 the name of the class of objects contained, to be written 
 on with lead-pencil. 
 
 Collecting Objects. The methods pursued by naturalists 
 generally will suffice for a large proportion of the objects 
 which are matters of microscopic inquiry, but there are 
 others which, from their minuteness, require special search. 
 Many fresh-water species of microscopic organisms inhabit 
 pools, ditches, and streams. Some attach themselves to 
 the stems and leaves of aquatic plants, or to floating and 
 decaying sticks, etc. Others live in the muddy sediment 
 at the bottom of the water. A pond stick has been con- 
 trived for the collection of such organisms, consisting of 
 two lengths, sliding one within the other, so that it may 
 be used as a walking-cane. In a screw socket at one end 
 may be placed a curved knife for cutting portions of plants 
 which contain microscopic parasites; or a screw collar for 
 carrying a screw-topped bottle, which serves to bring up 
 a sample of liquid ; or it may have a ring for a muslin net. 
 
 6 
 
82 THE MICROSCOPIST. 
 
 The net should be confined by an india-rubber band in a 
 groove, so as to be slipped off readily and emptied into a 
 bottle. The collector should have enough bottles to keep 
 organisms from each locality separate, and when animal- 
 cules are secured enough, air should be left to insure their 
 safety. 
 
 Marine organisms may be obtained in a similar way if 
 they inhabit the neighborhood of the shore, but others 
 can only be secured by means of the dredge or tow-net. 
 The latter may be of fine muslin sewn to a wire ring of 
 twelve inches diameter. It may be fastened with strings 
 to the stern of a boat, or held by a stick so as to project 
 from the side. For the more delicate organisms, the boat 
 should be rowed slowly, so that the net may move gently 
 through the water. Firmer structures may be obtained 
 by attaching a wide-mouthed bottle to the end of a net 
 made conical, and double, so that the inner cone may act 
 as a valve. The bottle may be kept from sinking by a 
 piece of cork. Such a net may be fixed to the stern of a 
 vessel, and drawn up from time to time for examination. 
 
 Minute organisms may be examined on the spot by 
 fishing them out of the bottle with a pipette, or small 
 glass tube, and placing them on a slide. A Coddington 
 or other pocket lens will suffice to show which are desir- 
 able for preservation. 
 
 Many of the lower animals and plants may be kept 
 alive in glass jars for some time. Frogs, etc., may be 
 kept under wire covers with a large piece of moist sponge. 
 
 Aquaria of various sorts may be procured and stocked 
 at small expense, and will afford a constant source of in- 
 struction. For fresh- water aquaria the bottom of the jar, 
 etc , should be covered with rich black earth, made into 
 a paste, and this should be surmounted with a layer of 
 fine washed sand. Roots of Valisneria, Anacharis, or 
 Cham may then be planted in the earth and the vessel 
 filled with water. As soon as the water is clear, put a 
 
MOUNTING AND PRESERVING OBJECTS. 8S 
 
 few fresh-water molluscs in to keep down the growth of 
 confervae, especially such as feed on decayed vegetable 
 matter, as Planorbis carinatus, Paludina vivipara, or Am- 
 phibia glutinosa. When bubbles of oxygen gas appear, 
 fish, water insects, etc., may be introduced. 
 
 Marine aquaria require more skill than those for fresh 
 water, but for temporary purposes, the plan described by 
 Mr. Highley, in Dr. Beale's How to Work with the Micro- 
 scope, is excellent. He fills a number of German beaker 
 glasses with fresh sea-water, and places them in a sunny 
 window. He then drops in each one or two limpet shells 
 from which the animals have been removed, and upon 
 which small plants of Enteromorpha and Ulva are growing. 
 In a short time the sides of the jars next the light become 
 coated with spores. He keeps the other sides clean with 
 a piece of wood or sponge, so as to observe the small 
 marine animals which may now be placed in the beakers. 
 In this way a collection will keep healthy for months. 
 After the sides are covered with spores, the sea-weeds 
 may be removed, and the jars placed on a table at such a 
 distance from the window that the light impinges only 
 on the coated half, taking care that there is sufficient light 
 to stimulate the spores to throw off bubbles of oxygen 
 daily. 
 
 Prawns, fish, actiniae, etc., may be fed on shreds of beef 
 which has been pounded and dried, and then macerated 
 in sea-water for a few minutes. All dead animals, slime, 
 or effete matter should be removed by wooden forceps, 
 etc , as soon as noticed. 
 
84 THE MICROSCOPIST. 
 
 CHAPTER VII. 
 
 THE MICROSCOPE IN MINERALOGY AND GEOLOGY. 
 
 MICROSCOPIC examination of minute fossil organisms, as 
 Diatoms, Foraminifera, spicules of sponge, etc., has long 
 been a subject of interest. Latterly, however, the micro- 
 scope has been found to be essential to the study of phys- 
 ical geology and petrology. How many crude and verbose 
 theories respecting cosmogony will disappear by this means 
 of investigation time must reveal, but the animal nature 
 of the Eozoon Canadense found in the Serpentine Lime- 
 stone of the Lauren tian formation of Canada, parallel with 
 the Fundamental Gneiss of Europe, and the discovery by 
 Mr. Sorby* of minute cavities filled with fluid in quartz 
 and volcanic rocks, are indications that speculations based 
 upon a merely external or even chemical examination of 
 rock structures are immature and inadequate. 
 
 The systematic study of microscopic mineralogy and 
 geology will require a large outlay of time and patience, 
 and the field is one which is scarcely trodden. The plan 
 of this work will only permit a brief outline, sufficient to 
 aid a beginner, and indicating the value and the methods 
 of minute investigation. 
 
 Preparation of Specimens. Examination of the outer 
 surface of a mineral specimen, viewed as an opaque body 
 with a low power and by condensed light, is sometimes 
 useful. The metals and their alloys, with most of their 
 combinations with sulphur, etc , admit of no other method. 
 Occasionally, as in iron and steel, the microscopic structure 
 is best seen by polishing the surface, and then allowing 
 the action of very dilute nitric acid. Mr. Forbesf states 
 
 * See Beale's How to Work with the Microscope. 
 
 f The Microscope in Geology, Popular Science Keview, No. 25. 
 
THE MICROSCOPE IN MINERALOGY AND GEOLOGY. 85 
 
 that many vitreous specimens (quite transparent) show no 
 trace of structure until the surface has been carefully acted 
 on by hydrofluoric acid. 
 
 It is generally necessary to have the specimens flat and 
 smooth, and thin enough to transmit light. Sometimes 
 fragments may be thin enough to show structure when 
 mounted in balsam, as in the case of quartz, obsidian, pitch- 
 stone, etc., but usually thin sections must be ground and 
 polished. 
 
 Chip off a fragment of the rock as flat and thin as pos- 
 sible, or cut with a lapidary's wheel, or a toothless saw of 
 sheet-iron with emery. Grind down the specimen on an 
 iron or pewter plate in a lathe until perfectly flat. Then 
 grind with finer emery on a slab of fine-grained marble or 
 slate, and finish with water on a fine hone, avoiding all 
 polishing powders or oil. When perfectly smooth, cement 
 the specimen on a square of glass with Canada balsam, 
 and grind the other side until as thin as necessary, finish 
 as before, remove it from the glass, and mount on a glass 
 slide in balsam. 
 
 In this way, most silicates, chlorides, fluorides, carbo- 
 nates, sulphates, borates, many oxides, sulphides, etc., may 
 be prepared for examination by transmitted light. Very 
 soft rocks may be soaked in turpentine, then in soft balsam, 
 and afterwards heated until quite hard. The deep scratches 
 on hard minerals, like quartz, left by the use of coarse 
 emery, may be removed by using fine emery paper held 
 flat on a piece of plate glass, and finally polished with 
 rouge on parchment. Perhaps oxide of chromium from 
 its hardness will be found the best polishing material. 
 Crystals of soluble salts may be ground on emery paper 
 and polished with rouge. Sometimes much may be learned 
 by acting on one side only of a specimen with dilute acid. 
 
 Examination of Specimens. The object of microscopic 
 examination of minerals is to determine not only the nature 
 of the material of which they are composed, but also, and 
 
86 THE MICROSCOPIST. 
 
 chiefly, their structure, whether homogeneous, derived 
 from the debris of previous rocks, or from the agency of the 
 organic world. Ordinary mineralogical characteristics, as 
 to hardness, specific gravity, color, lustre, form, cleavage, 
 and fusibility, and above all, chemical composition, may 
 suffice to show the material, but the microscope will give 
 valuable assistance to this end, and is essential to a knowl- 
 edge of structure. 
 
 Crystalline Forms. The laws of crystallography teach 
 that each chemical combination corresponds to a distinct 
 relation of all the angles which can possibly arise from 
 the primary form, so that the angular inclination of the 
 facets of a crystal is a question of importance. This can 
 be ascertained by a microscope having a revolving stage, 
 properly graduated, or by the use of a goniometer, which 
 is a thread stretched across the focus of the eye-lens, and 
 attached to a movable graduated circle and vernier. The 
 eye-piece attached to the polariscope of Hartnack is thus 
 arranged, so as to act also as a goniometer. 
 
 Crystals are assumed to possess certain axes, and the 
 form is determined by the relation of the plane surface to 
 these axes. . Although the forms of crystals are almost 
 infinitely varied, they may be classified into seven crystal- 
 lographic systems. 
 
 1. The Regular Cubic or Monometric System (Fig. 39) 
 These crystals are symmetrical, about three rectangular 
 axes. The simplest forms are the cube and octahedron. 
 Examples, diamond, most metals, chloride of sodium, fluor 
 spar, alum. 
 
 2. The Quadratic or Dimetric System (Fig. 40). Crystals 
 symmetrical, about three rectangular axes, but only two 
 axes of equal length. Examples, sulphate of nickel, tung- 
 state of lead, and double chloride of potassium and cop- 
 per. 
 
 3. Hexagonal or Rhombohedral System (Fig. 41). Crys- 
 tals with four axes ; three equal in length, in one plane, 
 
FIG. 39. 
 
 Principal or Vertical Axes. Secondary or Lateral Axes. 
 
 FIG. 41. 
 
 Principal Axes. Secondary Axes. 
 
 FIG. 42. 
 
 Principal Axes, Secondary Axes. 
 
 FIG. 43. 
 
 Principal Axes. Secondary Axes. 
 
 FIG. 44. 
 
 Principal Axes. 
 
 Secondary Axes. 
 
88 THE MICROSCOPIST. 
 
 and inclined 60 to each other, and a principal axis at 
 right angles to the plane of the others. Examples, quartz, 
 beryl, and calc-spar. 
 
 4. Rhombic or Trimetric System (Fig. 42). Three rec- 
 tangular axes, all of different lengths. Examples, sulphate 
 of potassium, nitrate of potassium, sulphate of barium, 
 and sulphate of magnesium. 
 
 5. Oblique Prismatic or Monoclinic (Fig. 43). Two axes 
 obliquely inclined, and a third at right angles to the plane 
 of these two ; all three being unequal. Examples, ferrous 
 sulphate, sugar, gypsum, and tartaric acid. 
 
 6. Didinic System. Two axes at right angles, and a 
 third oblique to the plane of these ; the primary form 
 being a symmetrical eight sided pyramid. 
 
 7. Doubly Oblique Prismatic or Triclinic (Fig. 44). Three 
 axes all inclined obliquely and of equal length. Example, 
 sulphate of copper. 
 
 Crystalline structure being inherent in the nature of 
 the mineral, becomes perceptible by the manner of divi- 
 sion. A slight blow on a piece of calc-spar will separate 
 it into small rhombohedrons or parallelopipeds, or produce 
 internal fissures along the planes of cleavage, which will 
 suffice to determine their angles. 
 
 Crystals are often found in groups, with various modes 
 of arrangement. Cubes are sometimes aggregated so as 
 to form octahedra, and prismatic crystals are often united 
 together at one extremity. But the most singular groups 
 are those called hemitropes, because they resemble a crys- 
 tal cut in two, with one part turned half round and re- 
 united to the other. 
 
 In all the numerous forms, however, we find in the same 
 species the same angles or inclination of planes, although 
 the unequal size of the faces may lead to great apparent 
 irregularity, as in distorted crystals of quartz, where one 
 face of the pyramid is enlarged at the expense of the rest. 
 
THE MICROSCOPE IN MINERALOGY AND GEOLOGY. 89 
 
 An apparent distortion may also be produced by an oblique 
 section. 
 
 The following examples may be of service, as showing 
 the value of angular measurement in minerals: 
 
 Quartz. Rhombohedral system. Inclination of two 
 adjoining faces 94 15'. 
 
 Felspar. Monoclinic. Cleavage planes at right angles. 
 
 Albite or soda felspar. Triclinic. Angle 93 36'. 
 
 Mica. Oblique prisms. 
 
 Maguesian mica. Right, rhombic, or hexagonal prisms. 
 
 Garnet. Dodecahedrons or trapezohedrons. 
 
 Idocrase. Square prisms. 
 
 Epidote. Oblique prisms. 
 
 Scapolite. Square and octagonal prisms. 
 
 Andalusite. Prisms of 90 44'. 
 
 Staurotide. Rhombic prisms of 129 20'. 
 
 Tourmaline. Three, six, nine, or twelve-sided prisms. 
 
 Topaz. Rhombic prisms of 124 19'. 
 
 Beryl. Six-sided prisms. 
 
 Hornblende. Monoclinic. 124 30'. 
 
 Augite or pyroxene. Monoclinic. 87 5'. 
 
 Calcite or carbonate of lime. Forms various, but 105 
 5' between the cleavage faces. 
 
 Magnesite. Angle 107 29'. 
 
 Dolomite. 106 15'. 
 
 Gypsum. Monoclinic. 
 
 Crystals within Crystals. Many specimens which appear 
 perfectly homogeneous to the naked eye are shown by the 
 microscope to be very complex. The minerals of erupted 
 lavas are often full of minute crystals, leading to very 
 anomalous results of chemical analysis. Some care is 
 needed at times to distinguish such included minerals 
 from cavities filled with fluid. The use of polarized light 
 will sometimes determine this point. 
 
 Cavities in Crystals. Mr. Sorby has shown that the 
 various cavities in minerals containing air, water, glass, 
 
90 THE MICROSCOPIST. 
 
 or stone will often indicate under what conditions the 
 rock was formed. Thus crystals with water cavities were 
 formed from solution ; those with stone or glass cavities 
 from igneous fusion ; those with both kinds by the com- 
 bined influence of highly heated water and melted rock 
 under great pressure; while those that contain no cavi- 
 ties were formed very slowly, or from the fusion of homo- 
 geneous substance. 
 
 Use of Polarized Light. Mr. Sorby states that the 
 action of crystals on polarized light is due to their double 
 refraction, which depolarizes the polarized beam, and 
 gives rise to colors b} 7 interference if the crystal be not 
 too thick in proportion to the intensity of its power of 
 double refraction. This varies much, according to the 
 position in which the costal is cut, yet we may form a 
 general opinion, since it is the intensity and not the char- 
 acter of the depolarized light which varies according to 
 the position of the crystal. There are two axes at right 
 angles to each other, and when either of them is parallel 
 to the plane of polarization, the crystal has no depolariz- 
 ing action, and if the polarizing and analyzing prisms are 
 crossed, it looks black. On rotating the crystal or the 
 plane of polarization, the intensity of depolarizing action 
 increases until the axes are at 45, and then diminishes 
 till the other axis is in the plane. If, therefore, this takes 
 place uniformly over a specimen, we know that it has one 
 .simple crystalline structure, but if it breaks up into de- 
 tached parts, we know it is made up of a number of sepa- 
 rate crystalline portions. 
 
 The definite order that may occur in the arrangement 
 of a number of crystals may indicate important differences. 
 Some round bodies, for example, like oolitic grains, have 
 been formed by crystals radiating from a common nu- 
 cleus ; whilst others, as in meteorites, have the structure 
 of round bodies which crystallized afterwards. 
 
 Sir .D. Brewster discovered that many crystals have 
 
THE MICROSCOPE IN MINERALOGY AND GEOLOGY. 91 
 
 two axes of double refraction, or rather axes around which 
 double refraction occurs. Thus nitre crystallizes in six- 
 sided prisms, with angles of about 120. It has two axes 
 of double refraction inclined about 2J to the axes of the 
 prism, and 5 to each other, so that a piece cut from such 
 a crystal perpendicular to the axes, shows a double system 
 of rings when a ray of polarized light is transmitted. 
 When the line connecting the axes is inclined 45 to the 
 plane of polarization, a cross is seen, which gradually 
 assumes the form of two hyperbolic curves on rotating 
 the specimen If the analyzer be revolved, the black cross 
 will be replaced by white, the red rings by green, the yel- 
 low by indigo, etc. These rings have the same colors as 
 thin plates, or a system of rings round one axis. Mica 
 has two sets of rings, with the angle between the axes of 
 60 to 75. Magnesian mica gives an angle of 5 to 20. 
 Determination of the Origin of Rock Specimens. Mr. 
 Forbes has shown that the primary or eruptive rocks, 
 consisting chiefly of crystallized silicates, with small 
 quantities of other minerals, are developed as more or 
 less perfect crystals at all angles to one another, indicat- 
 ing the fluid state of the mass at some previous time. 
 The secondary or sedimentary rocks consist of rocks 
 formed by the immediate products of the breaking up of 
 eruptive rocks, or are built of the debris of previous erup- 
 tive or sedimentary rocks, or composed of extracts from 
 aqueous solution by crystallization, precipitation, or the 
 action of organic life. The accompanying figures, selected 
 from Mr. Forbes's article in the Popular Science Review, 
 well illustrate this method of investigation. Plate II, 
 Fig. 45, is a section of lava from Vesuvius, magnified 
 twelve diameters, showing crystals of augite in a hard 
 gray rock. Plate II, Fig. 46, is a volcanic rock from 
 Tahiti, consisting of felspar, with oliviue and magnetic 
 oxide of iron, and numerous crystals of a pyroxenic min- 
 eral. Plate II, Fig. 47, is pitchstone from a dyke in new 
 
92 THE MICROSCOPIST. 
 
 red sandstone, magnified seventy-five diameters. Exter- 
 nally it resembles dirty green bottle-glass, but shows in 
 the microscope an arborescent crystallization of a green 
 pyroxenic mineral in a colorless felspar base. Plate II, 
 Fig. 48, shows auriferous diorite from Chili, consisting of 
 felspar, with hornblende and crystals of iron pyrites, mag- 
 nified thirty diameters. Plate II, Fig. 49, is a section of 
 granite from Cornwall, with crystals of orthoclase, hexag- 
 onal crystals of brown mica, and colorless quartz, which 
 a higher power shows to contain fluid cavities, magnified 
 twenty-five diameters. Plate II, Fig. 50, a volcanic rock 
 from Peru, composed of felspar, dark crystals of augite, 
 hexagonal crystals of dark mica, and a little magnetic 
 oxide of iron, magnified six diameters. Plate II, Fig. 
 5 1 , lower silurian roofing-slate, cut at right angles to the 
 cleavage, showing that the latter is not due to crystalline 
 but to mechanical arrangement, magnified two hundred 
 
 O O 
 
 diameters. Plate II, Fig. 52, is an oolitic specimen from 
 Peru, regarded as an eruptive rock by D'Orbigny, but 
 shown in the microscope to be a mere aggregation of 
 sand, etc., without the crystalline character of eruptive 
 rocks. 
 
 Materials of Organic Origin. Rocks and strata derived 
 from plants or animals may be arranged in four groups : 
 1. The calcareous, or those of which limestones have been 
 formed, as corals, corallines, shells, crinoids, etc. 2. The 
 siliceous, which have contributed to the silica, and may 
 have originated flints, as the microscopic shields of dia- 
 toms and siliceous spiculae of sponges. 3. The phosphatic, 
 as bones, excrement, etc. Fossil excrements are called 
 coprolites, and those of birds in large accumulations, 
 guano. 4. The carbonaceous, or those which have afforded 
 coal and resin, as plants. 
 
 To examine the structure of coal, it is necessary to have 
 very thin sections. From its friability, this is a process 
 of great difficulty. The Micrographic Dictionary recom- 
 
PI ATE 71. 
 
 Tig. 51x200 
 
 Tig. 52 * 30 
 
THE MICROSCOPE IN MINERALOGY AND GEOLOGY. 93 
 
 mends the maceration of the coal for about a week in a 
 solution of carbonate of potassium, when thin slices may 
 be cut with a razor. These should be gently heated in 
 nitric acid, and when they turn yellow, washed in cold 
 water and mounted in glycerin, as spirit and balsam ren- 
 der them opaque. Sometimes, as in anthracite, casts of 
 vegetable fibres may be obtained in the ash after burning 
 and mounted in balsam. 
 
 The lignites of the tertiary period show a vegetable 
 structure similar to the woods of the present period, but 
 the older coal of the palaeozoic series is a mass of decom- 
 posed vegetable matter chiefly derived from the decay of 
 coniferous wood, analogous to the araucarise, as is seen 
 from the peculiar arrangement of the glandular dots on 
 the woody fibres. Traces of ferns, sigillarise, calarnites, 
 etc., such as are preserved in the shales and sandstones of 
 the coal period, are also met with, but their structure has 
 not been preserved. 
 
 Professor Heer, of Zurich, has described and classified 
 several hundred species of fossil plants from the rniocene 
 beds of Switzerland by the outlines, nervation, and micro- 
 scopic structure of the leaves and character of sections of 
 the wood. Several hundred kinds of insects also have 
 been found in the same strata. It is remarkable that a 
 great part of this fossil flora is such as is now common 
 to America, as evergreen oaks, maples, poplars, ternate- 
 leaved pines, and the representatives of the gigantic 
 sequoise of California. 
 
 The researches of palaeontologists have brought to light 
 nearly two thousand species of fossil plants, of which 
 about one-half belong to the carboniferous and one-fourth 
 to the tertiary formations. 
 
 The rapid multiplication of the minute microscopic 
 organisms called diatoms, is such that Professor Ehren- 
 berg affirms it to have an important influence in blocking 
 up harbors and diminishing the depth of channels. These 
 
94 THE MICROSCOPIST. 
 
 organisms, now generally regarded as plants, are exceed- 
 ingly small, and are usually covered by loricse or shields 
 of pure silica, beautifully marked, as if engraved. These 
 loricre or shells having accumulated in great quantities, 
 have given rise to very extensive siliceous strata. Thus 
 the "infusorial earth" of Virginia, on which Richmond 
 and Petersburg are built, is such a deposit eighteen feet 
 in thickness. The polishing material called Tripoli, and 
 
 FIG. 53. 
 
 Fossil Diatomacese, etc., from Mourne Mountain, Ireland: a, a, a, Gaillom lla (Mclo- 
 seira) procera, and G. granulata, </, d, d, G. biseriata (side view); b, 6, Surirella {dicata ; 
 c, S, craticula; k, S, caledonica; e, Goinphonema gracile; /, Cocconeina fusidiuui; g, 
 Tabellaria vulgaris; h, 1'inuularia dactylus; i, P. nobilis; /, Synedra ulna. (From 
 Carpenter.) 
 
 the deposit called in Sweden and Xorway berg-mehl or 
 mountain flour, because used in times of scarcity to mix 
 with flour for bread, are similarly composed. Strata of 
 white rock in the anthracite region of Pennsylvania, and 
 from the sides of the Sierra Nevada and Cascade ranges 
 in California and Oregon, have also been found to consist 
 
 O ' 
 
 of such remains ;Fig. 53). 
 
THE MICROSCOPE IN MINERALOGY AND GEOLOGY. 95 
 
 The lowest type of animal life, consisting of minute 
 portions of sarcode or animal jelly, having the power of 
 putting forth prolongations of the body at will, contain 
 some forms which cover themselves with shells, usually 
 many-chambered, of carbonate of lime. From the pores 
 in these shells, through which the root-like processes of 
 sarcode are protruded, they are called Foraminifera. 
 
 FIG. 54. 
 
 Fossil Polycystina, etc., from Barbadoes: a, Podocyrtis mitra; b, Rhabdolithus scep- 
 trum; c, Lychnocaniurn falciferum; d, Encyrtidium tubulus; e, Flustrella conceutriea; 
 /, Lychnocanium lucerna; g, Encyrtidium elegans; h, Dictyospyris clathrus; ?, Encyr- 
 tidium mougolfieri; k, Stephanolithis spinescens; /, S, nodosa; m, Lithocyclia ocellus; 
 n, Cephalolithis sylvina; o, Podocyrtis cothurnata ; p, Rhabdolithes pipa. (From Car- 
 penter.) 
 
 Another class, the Pofycystina, secrete a siliceous shell, 
 usually of one chamber. The accumulations of the Fo- 
 raminifera have formed our chalk beds, while the Polycys- 
 tina have contributed to siliceous strata, like the Diato- 
 macece (Fig. 54). 
 
 The origin of white chalk strata has been illustrated 
 
96 THE MICROSCOPIST. 
 
 by the deep-sea soundings made preparatory to laying 
 the telegraph cable across the Atlantic Ocean. Professor 
 Huxley found the mud composing the floor of the ocean 
 to consist of minute Rhizopods or Forainihifera, of the 
 genus Q-lobigerina, together with Polycystina and Dia- 
 toms, and a few siliceous spiculse of sponges. These were 
 connected by a mass of living gelatinous matter, to which 
 he has given the name of Bathybius, and which contains 
 minute bodies termed Coccoliths and Coccospheres, which 
 have also been detected in fossil chalk. It is said that 
 95 per cent, of the mud of the North Atlantic consists of 
 Globigerina shells. 
 
 To examine Foraminifera in chalk, rub a quantity to 
 powder in water with a soft brush, and let it settle for a 
 variable time. The first deposits will contain the larger 
 specimens, with fragments of shell, etc. ; the smaller fall 
 next, while the amorphous particles suspended in the 
 water may be cast aside. After drying such specimens 
 as may be selected by the use of a dissecting microscope 
 or Coddington lens, etc., they may be mounted in balsam. 
 
 The flint found in chalk often contains Xanthidia, 
 which are the sporangia of Desmidiacese, as well as speci- 
 mens of sponge, Foraminiferal shells, etc. They must be 
 cut as other hard minerals. 
 
 There are other deposits besides chalk which are seen 
 by the microscope to consist of minute shells, corals, 
 etc. A section of oolitic stone will often show that each 
 rounded concretion is composed of a series of concentric 
 spheres inclosing a central nucleus which may be a forami- 
 niferal shell. The green sand formation is composed of 
 the casts of the interior of minute shells which have them- 
 selves entirely disappeared. The material of these casts, 
 chiefly silex colored with iron, has not only filled the cham- 
 bers of the shells, but has penetrated the canals of the 
 intermediate skeleton. 
 
 The more recent discovery by Drs. Dawson and Carpen- 
 
THE MICROSCOPE IN MINERALOGY AND GEOLOGY. 9T 
 
 ter of the organic nature of those serpentine limestones- 
 in the Laurentian formations of Canada and elsewhere, 
 which are products of the growth of the gigantic forami- 
 niferal Eozoon Canadense, over immense areas of the 
 ancient sea-bottom, is one of still greater interest both to 
 the student of Geology and of Biology. 
 
 This immense rhizopod appears to have grown one layer 
 over another, and to have formed reefs of limestone as do 
 the living coral-polyps. Parts of the original skeleton, 
 consisting of carbonate of lime, are still preserved, while 
 certain interspaces have been filled up with serpentine and 
 white augite. 
 
 Microscopic Paleontology. As a general rule it is only 
 the hard parts of animal bodies that have been preserved 
 in a fossil state. 
 
 It will o;ten occur that the inspection of a microscopic 
 fragment of such a fossil will reveal with certainty the 
 entire nature of the organism to which it belonged. Thus 
 minute fossil corals, the spines of Echinodermata, the 
 eyes of Trilobites, etc., will determine the position to 
 which we should ascribe the specimen, or a section of tooth 
 or bone will enable the microscopist to assign the fossil to 
 its proper class, order, or family. Thus Professor Owen 
 identified by its fossil tooth, the Labyrinthodon of War- 
 wickshire, England, with the remains in the Wittemberg 
 sandstones, and declared it to be a gigantic frog with some 
 resemblances both to a fish, and a crocodile. This predic- 
 tion the subsequent discovery of the skeleton confirmed. 
 
 The minute structure of teeth differs greatly in differ- 
 ent animals. In the shark tribe of fishes the dentine is 
 very similar to bone, excepting that the lacunse of bone 
 are absent. In man and in the Carnivora the enamel is a 
 superficial layer of generally uniform thickness, while in 
 many of the Herbivora the enamel forms with the cemen- 
 tum a series of vertical plates which dip into the substance 
 of the dentine. Enamel is wanting in serpents, Edentata, 
 
 7 
 
98 THE MICROSCOPIST. 
 
 and Cetacea. Such differences make it quite possible to 
 distinguish the affinities of a fossil specimen from a small 
 fragment of tooth. 
 
 In a similar way the microscopic characters of bone vary. 
 The bones of reptiles and fishes have the cancellated struc- 
 ture throughout the shaft, while the lacunee present very 
 great varieties, so that an animal tribe may be determined 
 by their measurement. In this way many contributions 
 have already been made to palaeontology. 
 
 CHAPTER VIII. 
 
 THE MICROSCOPE IN CHEMISTRY. 
 
 THE value of microchemical analysis, and the simplicity 
 of its processes, commend this department of microscopy 
 to general favor. 
 
 A large proportion of the actions and changes produced 
 by reagents may be observed as satisfactorily in drops as 
 in larger quantities. The decompositions effected by a 
 galvanic battery far smaller than that contained in a lady's 
 silver thimble, which deflected the mirror at the other end 
 of the Atlantic Telegraph Cable, may be readily observed 
 with a microscope. 
 
 Apparatus and Modes of Investigation. A few flat and 
 hollow glass slides, thin glass covers, test-tubes, small 
 watch-glasses, a spirit-lamp or Bunsen's burner, constitute 
 nearly all the furniture which is essential. 
 
 Dr. Wormley* directs that a drop of the solution to be 
 examined should be placed in a watch-glass, and a small 
 portion of reagent added with a pipette. The mixture 
 
 * The Microchemistry of Poisons, fcy Dr. Wormley. 
 
THE MICROSCOPE IN CHEMISTRY. 99 
 
 may then be examined with the microscope. If there is 
 no precipitate, let it stand several hours and examine again. 
 Dr. Beale prefers a flat or concave slide, and suggests that 
 if a glass rod be used for carrying the reagent, it must be 
 washed each time, or a portion may be transferred from 
 the slide to the bottle. He also advises the use of small 
 bottles with capillary orifices for reagents. Dr. Lawrence 
 Smith uses small pipettes with the open end covered by 
 india-rubber. 
 
 If heat be required, the drop may be boiled on the slide 
 over a spirit-lamp, or a strip of platinum-foil or mica may 
 be held with forceps so as to get a red or white heat from 
 the lamp or a Bunsen burner. This is especially needed 
 to get rid of organic matters. 
 
 For the examination of earthy materials, as carbonate 
 or phosphate of lime, phosphate of ammonia and magne- 
 sia, sulphates or chlorides, a small fragment may be placed 
 on a slide and covered with thin glass. A drop of nitric 
 acid is then put near the edge of the cover. If bubbles 
 escape a carbonate is indicated. Neutralize the acid with 
 ammonia ; let the flocculent precipitate stand awhile ; 
 cover and examine with the microscope. After a time, 
 amorphous granules and prisms will show phosphates of 
 ammonia, magnesia, and lime. Sulphates are shown by 
 adding to the nitric acid solution nitrate of barytes, and 
 chlorides by nitrate of silver. 
 
 Dr. Beale recommends adding glycerin to the test solu- 
 tions. The reactions are slower but more perfect, and the 
 crystalline forms resulting are more complete. 
 
 If a sublimate be desired, a watch-glass can be inverted 
 over another, and the lower one containing the material, 
 as biniodide of mercury, etc., heated over a spirit-lamp, 
 or the sublimation may be made in a reduction-tube. 
 
 Preparation of Crystals for the Polariscope. Many speci- 
 mens may be prepared by concentrating the solution with 
 heat and allowing it to cool. It should not be evaporated 
 
100 THE MICROSCOPIST. 
 
 to dryness. Many salts may be preserved in balsam, but 
 some are injured by it, and need glycerin or castor oil as 
 a preserving fluid. 
 
 The method of crystallization may be modified in vari- 
 ous ways so as to obtain special results. Thus if a solu- 
 tion of sulphate of iron is suffered to dry on a slide, the 
 crystals will be arborescent and fern-like, but if the liquid 
 is stirred with a glass rod or needle while evaporating, 
 separate rhombic prisms will form, which give beautiful 
 colors in the polariscope. Pyrogallic acid also crystallizes 
 in long needles, but a little dust, etc., as a nucleus, brings 
 about a change of arrangement resembling the "eye" of 
 the peacock's tail. 
 
 A saturated solution dropped into alcohol, if the salt is 
 insoluble in alcohol, will produce instantaneous crystals. 
 
 To obtain the best results, some crystals, as salicin, 
 should be fused on a slide over the lamp, and the matter 
 spread evenly over the surface. This may be done with 
 a hot needle. The temperature greatly affects the char- 
 acter of the crystallization. If very hot, the crystals run 
 in lines from a common centre. A medium temperature 
 produces concentric waves. 
 
 Many new forms result from uniting different salts in 
 different proportions. The knowledge of these different 
 effects can only be attained by experience. 
 
 Sections of crystals, as nitrate of potash, etc., to show 
 the rings and cross in the polariscope, are difficult to 
 make. After cutting a plate with a knife to about one- 
 fourth of an inch thick, it may be filed with a wet file to 
 one-sixth of an inch, smoothed on wet glass with fine 
 emery, and polished on silk strained over a piece of glass, 
 and rubbed with a mixture of rouge and tallow. The 
 nitre must be rubbed till quite dry, and the vapor of the 
 fingers prevented by the use of gloves. 
 
 For a general account of the use of polarized light, see 
 Chapter VI. 
 
THE MICROSCOPE IN CHEMISTRY. 101 
 
 The Use of the Microspectroscope. We have already de- 
 scribed this accessory in Chapter III. It promises im- 
 portant results in chemical analysis, but requires delicate 
 observation and exact measurements, together with a 
 careful and systematic study of a large number of colored 
 substances. 
 
 In using the microspectroscope, much depends on the 
 regulation of the slit. It should be just wide enough to 
 give a clear spectrum without irregular shading. As a 
 general rule, it should be just wide enough to show Frau- 
 enhofer's lines indistinctly in daylight. The slit in the 
 side stage should be such that the two spectra are of 
 equal brilliancy. Xo light should pass up the microscope 
 but such as has passed through the object under exam- 
 ination. This sometimes requires a cap over the object- 
 glass, perforated with an opening of about one-sixteenth 
 of an inch for a one and a half inch objective. 
 
 The number, position, width, and intensity of the ab- 
 sorption-bands are the data on which to form an opinion 
 as to the nature of the object observed, and Mr. Sorby 
 has invented a set of symbols for recording such observa- 
 tions. (See Dr. Beale's How to Work with the Microscope.) 
 These bands, however, do not relate so much to the ele- 
 mentary constitution as to the physical condition of the 
 substance, and vary according to the nature of the solvent, 
 etc., yet many structures give such positive effects as to 
 enable us to decide with confidence what they are. 
 
 Colored beads obtained by ordinary blowpipe testing, 
 sections of crystals, etc., cut wedge-shaped so as to vary 
 their thickness, often give satisfactory results. But 
 minute quantities of animal and vegetable substances, as 
 blood-stains, etc., dissolved and placed in short tubes 
 fastened endwise on glass slides, or in some other conve- 
 nient apparatus, offer the most valuable objects of re- 
 search. 
 
 To measure the exact position of the absorption-bands, 
 
102 
 
 THE MICROSCOPIST. 
 
 the micrometer already described may be used, or Mr. 
 Sorby's apparatus, giving an interference spectrum with 
 twelve divisions, made by two Mcol's prisms, with an 
 intervening plate of quartz of the required thickness. 
 
 The value of this mode of investigation in medical 
 chemistry, and for purposes of diagnosis or jurisprudence, 
 may be seen by the following illustrations:* 
 
 Pettenkofer 's Test for Bile (Fig. 55). To a few drops of 
 bile in a porcelain dish, add a drop of solution of cane- 
 
 A a 7? C 
 
 Pettenkofer's Bile-lYst. 
 
 sugar, and then concentrated sulphuric acid drop by drop, 
 with agitation. The mixture becomes a purple-red color, 
 and shows a spectrum as in the figure. The color will 
 be destroyed by water and alcohol. 
 
 Tests for Blood. Hsematocrystalline, or cruorin, com- 
 posed of an albuminoid substance and haematin, generally 
 crystallizes in tetrahedra or octahedra. In blood from 
 
 A a B C 
 
 E b 
 
 FIG. 56. 
 F 
 
 H ir 
 
 1.1 ... 
 
 Blood. 
 
 the horse and from man only an amorphous deposit is 
 found. The watery solution of this substance properly 
 diluted, shows two remarkable bands of absorption, and 
 obscuration of the blue and violet end of the spectrum 
 (Fig. 56). As the blood of all vertebrates shows the same 
 
 * See Thudichum 's Manual of Chemical Physiology. New York, 1872. 
 
THE MICROSCOPE IN CHEMISTRY. 
 
 103 
 
 bands, it is judged that haematocrystalline is present in it 
 as such, and not formed from it. By treating a solution 
 of blood which exhibits the two absorption-bands with 
 hydrogen, or with a solution of ferrous sulphate contain- 
 ing tartaric acid and excess of ammonia, taking care to 
 
 A a B r 
 
 H H" 
 
 Reduced Hsniutocrystalline. 
 
 exclude the air, the color of the solution changes to pur- 
 ple, and the spectroscope shows only one broad band in- 
 stead of two (Fig 57). Shaking with air will restore the 
 two bands. By treating blood with hydrothion or am- 
 
 A n B 
 
 n rr 
 
 Blood treated with Ammonium Sulphide. 
 
 monium sulphide, three bands make their appearance, as 
 in Fig. 58. 
 
 Haematin is seen by the microscope to consist of small 
 
 H w 
 
 Four-banded Hitnuttiu. 
 
 rhombic crystals. Dissolved in alcohol and a little sul- 
 phuric acid, the spectrum shows four, and under some 
 circumstances five, bands (Fig. 59). Rendered alkaline 
 
104 
 
 THE MICROSCOPIST. 
 
 by caustic potash, one broad band appears (Fig. 60\ 
 Acid will restore the former spectrum. 
 
 Dissolve haematin in water with a little caustic potash. 
 
 A a B 
 
 I li ; ! 
 
 Alkaline Haeinatiu. 
 
 To a solution of ferrous sulphate, add tartaric acid and 
 then ammonia till alkaline. Pour a little of the clear 
 mixture into the hsematin solution. The spectrum of re- 
 
 A a B C 
 
 JT TT' 
 
 Reduced Ha^matin. 
 
 duced heematin will show two bands (Fig. 61). Shaking 
 with air will restore the former spectrum. 
 
 L/utein Spectra. The juice of the corpora lutea, to which 
 sulphuric acid and a little sugar is added, gives a fine 
 
 A < 
 
 i ) 
 
 ? ( 
 
 7 1 
 
 1 
 > Eh 
 
 "IG. G2. 
 p 
 
 G HI 
 
 r 
 
 
 
 
 
 ' ^i. "!";] 
 
 \ll 
 
 ^\ 
 
 ' II' '" 1 IK 
 
 ll _J 111 
 
 i;i ,1 
 
 Juice of (Joipora Lutea with Sulphuric Acid. 
 
 purple color, and shows in the spectroscope one band in 
 the green (Fig. 62). Its chloroform solution, examined 
 with lime-light, shows two bands in blue (Fig. 63). An 
 alcoholic or ethereal solution gives a third one in the 
 violet. 
 
THE MICROSCOPE IN CHEMISTRY. 
 
 105 
 
 Cysto lutein, or the yellow fluid of an ovarian cyst, 
 shows with the lime-light three bands in blue, in the 
 
 n IT 
 
 Chloroform Suluiiou of Corpora Lutea. 
 
 same position as the chloroform solution of lutein (Fig. 
 61). 
 
 The serum of blood, etc., shows the bands of hsemato- 
 
 A n B 
 
 Cysto-Luteiu 1'ioui an Ovariau Cyst. 
 
 crystalline and one or two doubtful bands, as in the figure 
 (Fig. 65). 
 
 Dr. Richardson, of Philadelphia, gives the following 
 directions for examining blood-stains: Procure a glass 
 slide with a circular excavation, and moisten the edges 
 of the cavity with a small drop of diluted glycerin. Lay 
 
 A n B C 
 
 H TT 
 
 Sero-Lutein. 
 
 a clean glass cover, a little larger than the excavation, on 
 white paper, and put on it the smallest visible fragment 
 of blood-clot. With a needle, put on the centre of the 
 cover a speck of glycerin, not larger than a full stop (.), 
 
106 THE MICROSCOPIST. 
 
 and with a dry needle push the blood to the edge that it 
 may be just moistened with the glycerin. Place the slide 
 on the cover so that the glycerin edges of the cavity may 
 adhere, and turning it over, transfer it to the stage of the 
 microscope. Thus a minute quantity of a strong solution 
 of hsemoglobulin is obtained, the point of greatest density 
 of which may be found by a one-fourth objective, and 
 tested by the spectroscopic eye-piece and witlrhigh powers. 
 The tiny drop may be afterwards wiped off with moist 
 blotting-paper, and a little fresh tincture of guaiacum 
 added, showing the blue color of the guaiacum blood-test. 
 Inverted Microscope of Dr. Lawrence Smith. In ordinary 
 chemical investigations there is some risk of injuring the 
 polish of the lenses, as well as the brass work of the mi- 
 croscope, without very great care. This is particularly 
 the case in observing the effects of heat or of strong acids. 
 To obviate this difficulty, Dr. Lawrence Smith contrived 
 a plan for an inverted microscope, w r hich has been con- 
 structed by Cachet of Paris. The optical part of the in- 
 strument is below the stage, and is furnished with a pecu- 
 liar prism, by which the rays from the'objective are bent 
 into a conveniently inclined body. The illuminating ap- 
 paratus is above the stage. This, construction renders the 
 instrument well adapted to chemical investigations. 
 
 GENERAL MICROCHEMICAL TESTS. 
 
 Dr. Worm ley has directed attention to some necessary 
 cautions. He shows that many substances which may 
 readily be detected in a pure state, even in very minute 
 quantities by the microscope, are difficult to detect when 
 mixed \vith complex organic materials. This is especially 
 applicable to the alkaloids, which should be separated 
 from such mixtures by the use of the dialyzer a hoop 
 with a bottom of parchment-paper, etc. or extracted 
 with ether or chloroform. 
 
THE MICROSCOPE IN CHEMISTRY. 107 
 
 The purity of all reagents should be carefully estab- 
 lished, and they should be kept in hard German glass 
 bottles, and only distilled water used in all our researches. 
 
 The true nature of a reaction that is common to several 
 substances may often be determined with the microscope. 
 Thus 'a solution of nitrate of silver becomes covered with 
 a white film when exposed to several different vapors, but 
 hydrocyanic acid is the 'only one which is crystalline. 
 This will detect 100,000th of a grain of the acid. A slip 
 of clean copper boiled in a hydrochloric acid solution of 
 arsenic, mercury, antimony, etc., becomes coated with the 
 metal, but when heated in a reduction-tube, arsenic only 
 yields a sublimate of octahedral crystals, and mercury 
 only will furnish metallic globules. 
 
 A solution of iodine produces distinct reaction with 
 100,000th of a grain of strychnine in solution in 1 grain 
 of water, but as this is common to other alkaloids, other 
 tests are needed. Yet the absence of such a reaction 
 shows the -absence of the alkaloid. 
 
 The degree of dilution is important. Thus bromine with 
 atropin yieldsHa crystalline deposit from 1 grain of a 
 20,000th or stronger dilution, but not with diluter solu- 
 tions. A limited quantity of sulphuretted hydrogen 
 throws down from corrosive sublimate a white deposit, 
 while excess produces a black precipitate. 
 
 Blue and Reddened Litmus Paper are used as tests for 
 acids and alkalies. It is a bibulous paper dyed in infu- 
 sion of litmus. The red is made by adding a little acetic 
 acid to the infusion. Dry substances and vapors require 
 the paper to be moistened with distilled water. If the 
 acid reaction depends on carbonic acid, warming the paper 
 on a slide over a lamp will restore the color. So if a 
 volatile alkali, ammonia or carbonate of ammonia, have 
 made the red paper blue, its color will be restored by a 
 gentle heat. Sometimes the infusion of litmus is more 
 convenient than the paper. 
 
108 THE MICROSCOPIST. 
 
 Alcohol coagulates albuminous matter. 
 
 Ether dissolves fat. 
 
 Acetic Acid will dissolve phosphate or carbonate of lime, 
 but not the oxalate. 
 
 Nitrate of Barytes in cold saturated solution is a test for 
 sulphuric and phosphoric acids. The precipitated sulphate 
 of baryta is insoluble in acids and alkalies. The phosphate 
 is soluble in acids and insoluble in ammonia. 
 
 Nitrate of Silver. A solution of 60 grains to the ounce 
 of water is a convenient test for chlorides and phosphates. 
 Chloride of silver is white, soluble in ammonia and insolu- 
 ble in nitric acid. The tribasic phosphate of silver is yel- 
 low, and soluble in excess of ammonia or of nitric acid. 
 
 Oxalate of Ammonia is a test for salts of lime. Dissolve 
 the material in nitric acid, and add excess of ammonia. 
 Dissolve the flocculent precipitate in excess of acetic acid, 
 and add the oxalate of ammonia. Oxalate of lime is in- 
 soluble in alkalies and acetic acid, but soluble in strong 
 mineral acids. 
 
 Iodine is a test for starch, coloring it blue. Albuminous 
 tissues are colored yellow, and vegetable cellulose a brown- 
 ish-yellow. The addition of sulphuric acid turns cellulose 
 blue. 
 
 DETERMINATION OP SUBSTANCES. 
 ALKALIES. 
 
 Bichloride of platinum precipitates from salts of potash 
 or ammonia a yellow double chloride, which crystallizes 
 in beautiful octahedra. It has no precipitating effect on 
 solutions of soda. Polarized light will distinguish the 
 800,000th of a grain of double chloride of sodium and 
 platinum by its beautiful colors from the chloride of 
 potassium and platinum, or of platinum alone. The 
 double chloride of platinum and potassium may be dis- 
 tinguished from that of ammonia by heating to redness, 
 treating with hot water, and acting on with nitrate of 
 
THE MICROSCOPE IN CHEMISTRY. 109 
 
 silver. The ammonium compound after ignition leaves 
 only the platinum, which gives no precipitate with nitrate 
 of silver, while the potassium chloride yields a white pre- 
 cipitate of chloride of silver. 
 
 Antimoniate of potash throws down from solutions of 
 soda and its neutral salts a white crystalline antimoniate 
 of soda, the forms of which vary according to the strength 
 of the solution ; generally they are rectangular plates and 
 octahedra. 
 
 ACIDS. 
 
 Sulphuric. In solutions acidulated with hydrochloric 
 or nitric acid, the chloride or nitrate of baryta produces 
 a white precipitate. Veratrin added to a drop of concen- 
 trated sulphuric acid produces a crimson solution, or de- 
 posit if evaporated. 
 
 Citric. Heated with excess of hydrochloric acid elimi- 
 nates chlorine, which will dissolve gold leaf. A blood- 
 red color is produced when nitric acid or a nitrate is mixed 
 with a sulphuric acid solution of brucin. 
 
 Hydrochloric. Xitrate of silver precipitates amorphous 
 chloride of silver; soluble in ammonia, but insoluble in 
 nitric and sulphuric acid. 
 
 Oxalic. Xitrate of silver precipitates amorphous oxa- 
 late of silver ; soluble in nitric acid and also in solution 
 of ammonia. 
 
 Hydrocyanic. Put a drop of acid solution in a watch- 
 glass, invert another over it containing a drop of solution 
 of nitrate of silver, and a crystalline film will form. A 
 solution of hydrocyanic acid treated with caustic potash 
 or soda and then with persulphate of iron yields Prussian 
 blue. 
 
 Phosphoric. A mixture of sulphate of magnesia, chlo- 
 ride of ammonium, and free ammonia produces in solu- 
 tions of free phosphoric acid and alkaline phosphates 
 white feathery or stellate crystalline precipitate of ammo- 
 
110 THE MICROSCOPIST. 
 
 nio-phosphate of magnesia. A slower crystallization gives 
 prisms. 
 
 METALLIC OXIDES. 
 
 These may usually be determined by treating a small 
 portion of solution, acidulated with hydrochloric acid, by 
 sulphuretted hydrogen ; another, and neutral portion with 
 sulphuret of ammonium ; and a third with carbonate of 
 soda. 
 
 Antim.ony. Sulphuretted hydrogen throws down or- 
 ange-red precipitate from tartar-emetic solutions, etc. 
 
 Arsenic yields white octahedral crystals of arsenious 
 acid when sublimed. Arsenious acid may be reduced to 
 metallic arsenic by heating to redness in a tube with 
 charcoal and carbonate of soda. A solution of arsenious 
 acid yields octahedral crystals by evaporation, so as to 
 determine with the microscope 1000th to 10,000th of a 
 grain. 
 
 Ammonio-nitrate of silver throws down from an aque- 
 ous solution of arsenious acid a bright yellow precipitate, 
 arnmonio-sulphate of copper a green precipitate, and sul- 
 phuretted hydrogen a bright yellow. 
 
 Mercury. Bichloride of mercury, moistened with a drop 
 of solution of iodide of potassium, assumes the bright 
 scarlet color of biniodide of mercury. A strong solution 
 of caustic potash or soda turns bichloride of mercury yel- 
 low from the formation of protoxide ; but calomel or chlo- 
 ride of mercury is blackened from formation of suboxide. 
 Heated in a reduction-tube with dry carbonate of soda, 
 the sublimate shows under the microscope small, opaque, 
 spherical globules of mercury. Dr. Wormley states that 
 a globule of mercury or "artificial star" may be discrim- 
 inated by the one-eighth objective if it be but the 
 25,000th of an inch in diameter, weighing about the 
 9,000,000,000th of a grain ; globules of 5 ^th of an inch 
 diameter weigh about 70,000,000th of a grain. 
 
THE MICROSCOPE IN CHEMISTRY. Ill 
 
 Lead. Sulphuretted hydrogen gives a black amor- 
 phous deposit. Sulphuric and hydrochloric acids yield a 
 white precipitate. Chloride of lead crystallizes in needles. 
 Iodide of potassium gives a bright yellow precipitate, sol- 
 uble in boiling water, and crystallizing in. six-sided plates. 
 Bichromate of potassium yields a bright yellow amor- 
 phous deposit. 
 
 Copper. Sulphuretted hydrogen gives a brown or black- 
 ish deposit ; ammonia a blue or greenish-blue amorphous 
 precipitate, or in dilute solutions a blue color to the liquid ; 
 caustic alkali, a similar precipitate, which on boiling in 
 excess of reagent becomes black, but if grape-sugar, or 
 some other organic agents, be present, a yellow or red 
 precipitate of suboxide of copper occurs. Arsenite of 
 potassium produces a bright green. 
 
 Zinc. Sulphuretted hydrogen gives a white amorphous 
 deposit the only white sulphuret. Alkalies produce a 
 white hydrated oxide of zinc. 
 
 ALKALOIDS. 
 
 The editors of the Micrographic Dictionary refer to a paper 
 of Dr. T. Anderson, in the Edinburgh Monthly Journal, 
 where he shows that the microscope readily distinguishes 
 the more common alkaloids from each other by the form 
 of their crystals and of their sulphocyanides. The alka- 
 loids are first dissolved in dilute hydrochloric acid, then 
 precipitated on a glass plate with a solution of ammonia, 
 or if the sulphocyanide is required, with a strong solution 
 of sulphocyanide of potassium. It may then be placed 
 under the microscope. The solution should not be too con- 
 centrated. This branch of investigation has been greatly 
 promoted by the elegant work of Dr. Wormley, already 
 referred to, on the Microchemistry of Poisons. 
 
 Atropin. Ammonia throws down an amorphous pre- 
 cipitate. One grain of a T tJoth grain solution yields to 
 
112 THE MICROSCOPIST. 
 
 caustic potash or soda a precipitate which, when stirred 
 with a glass rod, becomes a mass of crystals, as in Plate 
 Til, Fig. 66. The sulphocyanide of potassium gives no 
 precipitate. 
 
 Aconitin. ~No characteristic test, except the physiologi- 
 cal one; ^oo^ 1 of a grain produces on the end of the 
 tongue a peculiar tingling and numbness, lasting for an 
 hour; T -J- th grain in alcohol, rubbed on the skin, pro- 
 duces temporary loss of feeling. 
 
 Bruein or Bruda. Potash or ammonia produces stellar 
 crystals. Sulphocyanide of potassium, feathery, or sheaf- 
 like. (Plate III, Fig. 67.) Nitric acid produces a blood- 
 red color, changing to yellow by heat. On cooling the 
 latter and adding protochloride of tin, it becomes a beau- 
 tiful purple. Ferri cyanide of potassium, with T -J D th grain 
 of brucin yields the most brilliant polariscope crystals. 
 (Plate III, Fig. 68). 
 
 Cinchonine. Ammonia produces granular radiating 
 crystals. (Plate III, Fig. 69.) Sulphocyanide of potas- 
 sium six-sided plates, some irregular. (Plate III, Fig. 70.) 
 
 Conine. This alkaloid and nicotin are distinguished 
 from other alkaloids by being liquid at ordinary tempera- 
 tures, and by their peculiar odor. Conine may be known 
 from nicotin by its odor and sparing solubility in water, 
 by yielding crystalline needles to the vapor or solution of 
 hydrochloric acid, a white precipitate with corrosive sub- 
 limate, and a dark-brown precipitate with nitrate of silver. 
 
 Codein. Ammonia or alkalies give a white amorphous 
 deposit. Sulphocyanide of potassium, crystalline needles. 
 A solution of iodine in iodide of potassium, a reddish- 
 brown precipitate, which becomes crystalline. This is 
 soluble in alcohol, from which it separates in plates (Plate 
 III, Fig. 71), which appear beautiful in the polariscope. 
 
 Dalurin. According to Dr. Wormley, this is identical 
 with atropin. 
 
 Narcotin. In its pure state crystallizes in rhombic 
 
PLATE III. 
 
 FIG. 66. 
 
 * 
 
 FIG. 71. 
 
 FIG. 67. 
 
 FIG. 72. 
 
 ^ -^ 
 -v d^ 
 
 /wt T f 
 
 FIG. 73. 
 
 FIG. 68. 
 
 FIG. i 
 
 FIG. 74. 
 
 FIG. 70. 
 
 o . O 
 
 O 
 
 FIG. 75. 
 
THE MICROSCOPE IN CHEMISTRY. 113 
 
 prisms, or oblong plates. Ammonia, the alkalies, and their 
 carbonates produce tufts of crystals (Plate III, Fig. 72). 
 A drop of aqueous solution of a salt of narcotin, exposed 
 to vapor of ammonia, is covered with a crystalline film if 
 it only contains g^^th of its weight of alkaloid. 
 
 Morphine. When pure crystallizes in short rectangular 
 prisms. Sulphuric acid dissolves them, and if bichromate 
 of potash be added, green oxide of chromium results. Con^ 
 centrated nitric acid turns it orange-red, and dissolves it_ 
 A strong solution treated with a strong solution of nitrate 
 of silver and gently heated, decomposes the latter and pro- 
 duces a shining crystalline precipitate of metallic silver. 
 In dilute solutions, alkalies precipitate a crystalline form 
 ( 'Plate III, Fig. 73). Xo precipitate with sulphocyanide 
 of potassium unless highly concentrated. 
 
 Quinine. Amorphous precipitate with ammonia. Sul- 
 phoc} T anide of potassium gives irregular groups of acicu- 
 lar crystals, like those produced by strychnine, but longer 
 and more irregular (Plate III, Fig 74 . The solution 
 should be dilute, and twenty-four hours allowed for the 
 crystals to form. 
 
 The iodo-disulphate, or Herapathite, gives crystals of a 
 pale olive-green color, which possess a more intense polar- 
 izing power than any other known substance. Dr. Hera- 
 path proposed this as a delicate test for quinine. A drop 
 of test-liquid made with 3 drachms of acetic acid, 1 
 drachm of rectified spirits, and 6 drops of dilute sulphuric 
 acid is placed on a slide and the alkaloid added. When 
 dissolved a little tincture of iodine is added, and after a 
 time the salt separates in little rosettes. By careful manip- 
 ulation crystals of this salt may be formed large enough 
 to replace Xicol's prisms or tourmaline plates in the polar- 
 izing apparatus. When the crystals of Herapathite cross 
 each other at a right-angle, complete blackness results. 
 Intermediate positions give a beautiful play of colors. 
 
 Strychnine. Ammonia gives small prismatic crystals, 
 
 8 
 
114 THE MICROSCOPIST. 
 
 some crossed at 60 (Plate III, Fig. 75). Sulphocyanide 
 of potassium produces flat needles, often in groups. Iodine 
 in iodide of potassium gives a reddish-brown amorphous 
 precipitate, crystalline in dilute solutions. When pure, 
 strychnine appears in colorless octahedra, lengthened 
 prisms or granules. To a solution of the alkaloid or its 
 salts in a drop of pure sulphuric acid, which produces no 
 color, add a small crystal of bichromate of potash, and 
 stir slowly with a pointed glass rod. A blue color will 
 appear, passing into purple, violet, and red. The bright 
 yellow crystals of chromate of strychnia, if dried and 
 touched with sulphuric acid, will also show the color test. 
 This is said to be delicate enough to show T0 ^ Tjth of a 
 grain of strychnine. The tetanic convulsions of frogs im- 
 mersed in a solution of strychnine, or after injections of 
 the solution in lungs or stomach, etc , is also a very deli- 
 cate test. 
 
 Veratrin and its salts treated in the dry state with con- 
 centrated sulphuric acid, slowly dissolve to a reddish-yel- 
 low, or pink solution, which becomes crimson-red. The 
 process is accelerated by heat. 
 
 Narcein, touched with the cold acid, becomes brown, 
 brownish-yellow, and greenish-yellow, and if heated, a 
 dark purple-red. 
 
 Solanin turns orange-brown, and later purplish-brown. 
 
 Piperin turns orange-red to brown. 
 
 Salicin gives to the acid a crimson pink, changing to 
 black. 
 
 Papaverin gives a fading purple. 
 
 CRYSTALLINE FORMS OF VARIOUS SALTS. 
 
 Our limits forbid extended description, yet a few forms 
 of frequent recurrence will be useful to the student. For 
 crystals in plants or from animal secretions reference may 
 be made also to succeeding chapters. 
 
 Salts of Lim.e. The carbonate sometimes occurs in ani- 
 
PLATE IV. 
 
 FIG. 76. 
 
 
 FIG. 80. 
 
 FIG. 77. 
 
 FIG. 81. 
 
 FIG. 78. 
 
 
 FIG. 82. 
 
 FIG. 79. 
 
 FIG. 83. 
 
 FIG. 84. 
 
 v/ 
 
THE MICROSCOPE IN CHEMISTRY. 115 
 
 mal secretions in the form of little spheres or disks, con- 
 sisting of groups of radiating needles. In otoliths it is 
 often in minute hexagonal prisms with trilateral summits. 
 It is deposited from water in irregular forms, all of which 
 are grouped needles. Sometimes it assumes the rhombo- 
 hedral form, as in the oyster shell (Plate IV, Fig. 76). 
 In any doubtful case, test as described at pages 99 and 
 108. 
 
 Lactate of Lime gives microscopic crystals, consisting of 
 delicate radiating needles (Plate IV, Fig. 77). 
 
 Oxalate of Lime occurs as square flattened octahedra, as 
 square prisms with quadrilateral pyramids, as fine needles, 
 and as ellipsoidal flattened forms, sometimes constricted 
 so as to resemble dumb-bells (Plate IV, Fig. 78). 
 
 Phosphate of Lime is usually in the form of thin rhombic 
 plates (Plate IV, Fig. 79). 
 
 Sulphate of Lime rapidly formed, as in chemical testing, 
 gives minute needles or prisms (Plate IV, Fig. 80). When 
 more slowly formed, these are larger and mixed with 
 rhombic plates. 
 
 Soda Salts. Chloride of Sodium or common salt gener- 
 ally forms a cube, terminated by quadrangular pyramids 
 or depressions (Plate IV, Fig. 81). The crystals do not 
 polarize light. 
 
 Plate IV, Fig. 82, represents crystals of oxalate of soda, 
 and Plate IV, Fig. 83, those of nitrate. 
 
 Magnesia Salts. Ammonia-phosphate^ or triple phosphate, 
 is often found in animal secretions. The most common 
 form is prismatic, but sometimes it is feathery or stellate 
 (Plate IV, Fig. 84). 
 
 Sulphate of Magnesia forms an interesting polarizing 
 object. 
 
 A most instructive series of salts may be made by 
 rapidly crystallizing some on glass slides, and allowing 
 others to deposit more slowly. In this way a set of speci- 
 mens may be prepared for comparison. 
 
116 THE MICBOSCOPIST. 
 
 CHAPTER IX. 
 
 THE MICROSCOPE IN BIOLOGY. 
 
 THE science of biology (from /?w<r, life), which treats of 
 the forms and functions of living beings, would be crude 
 and imperfect without the aid of the microscope. What- 
 ever might be learned by general observation, we should 
 miss the fundamental laws of structure and the unity 
 which we now know pervades distant and apparently 
 different organs, as well as distinct species, if we were 
 deprived of the education which microscopy gives the 
 eye and hand. 
 
 The evident differences between living and non-living 
 bodies led to ancient theories of life which are still influ- 
 ential in modern thought, but neither microscope nor 
 scalpel nor laboratory have revealed the mystery which 
 seems ever to beckon us onward to another and entirely 
 different sphere of existence. Hippocrates invented the 
 hypothesis of a principle (<pu<K<;, or nature) which influences 
 the organism and superintends it with a kind of intelli- 
 gence, and to which other principles (tiuvaneis, powers) are 
 subordinated for the maintenance of various functions. 
 This was also the theory of Aristotle, who gave the name 
 of soul (4>vw) to the animating principle. 
 
 Paracelsus and the chemical philosophers, from the 
 fifteenth to the seventeenth century, maintained that all 
 the phenomena of vitality may be explained by chemical 
 laws. To these succeeded the mathematical school under 
 Bellini (A.D. 1645), who taught that all vital functions 
 may be explained by gravity and mechanical impulse. 
 These theories were supplanted by those of the physiolo- 
 gists. Van Helmont revived the Hippocratian idea of a 
 specific agent, which he called archeus. This was more 
 fully elaborated by Stahl, who taught that by the opera- 
 
THE MICROSCOPE IN BIOLOGY. 117 
 
 tion of an immaterial animating principle or soul (ammo], 
 all vital functions are produced. The vis medicatrix na- 
 turce of Cullen was an attempt to compromise between 
 the rival theories of a superadded principle and a special 
 activity in organized matter itself.* 
 
 Harvey, Hunter, Miiller, and Prout proposed hypotheses 
 similar to those of Aristotle and Hippocrates, and many 
 modern scientific men accept similar views. The recent 
 doctrine of the correlation of physical forces has, however, 
 revived the mechanical and chemical theories, and the 
 industry with which these view^s have been propagated 
 has gained many adherents. 
 
 It is to be regretted that philosophy should assume the 
 name of science and dogmatize under that appellation. 
 The object of science is to state facts, and not to dream, 
 yet such is the nature of man's intellect that it will seek 
 to account for facts, and is thus drawn into metaphysical 
 speculation. If the age-long controversy between the 
 physicists and the vitalists is ever to cease, it will prob- 
 ably be through the microscopic demonstration of the 
 absolute difference between living and non-living matter. 
 
 In the present chapter it is designed to set forth briefly 
 the principal facts of elementary biology as they have 
 been brought to light by microscopy. For further illus- 
 trations in vegetable and animal histology, reference may 
 be made to following chapters. 
 
 1. All biologists agree that the elementary unit in living 
 bodies is the cell. This, according to the most recent in- 
 vestigations, is a soft, transparent, colorless, jelly-like par- 
 ticle of matter, which may be large enough to be just dis- 
 cernible to the naked eye, or so small as to be invisible 
 with our best instruments. The simplest or most elemen- 
 tary forms of vegetable or animal life consist of single 
 cells, while the more complex organisms are built up of 
 
 * Compare Bostock's History of Medicine. 
 
118 THE MICROSCOPIST. 
 
 great numbers of these cells with the materials which 
 they have produced and deposited. 
 
 Haller, who has been called the father of modern physi- 
 ology, seems first to have conceived, though vaguely 
 (A. I). 1766), the idea of the essential unity of vital struc- 
 ture. 
 
 In 1838, Schleiden and Schwann wrote on the elemen- 
 tary cell, the former treating of the vegetable, and the 
 latter of the animal cell. From this time may be dated 
 the origin of the cell doctrine. Much importance was 
 assigned to the distinction between cell-wall, cell-con tents, 
 nuclei, and nucleoli. 
 
 In 1835, Dujardin discovered in the lower animals a 
 contractile substance capable of movement, to which he 
 gave the name of sarcode. 
 
 In 1861, Max Schultze showed that sarcode is analo- 
 gous to the body or contents of animal cells, and that on 
 this account the infusorial animalcules possessed of inde- 
 pendent life were simple or compound. 
 
 Examinations of this structure were made by numerous 
 observers, and the identity of many of its properties in 
 animals and vegetables established. To this structure 
 the name of protoplasm, rather than sarcode, has been 
 assigned. As this term has been somewhat loosely used, 
 so as to refer to it either in the dead or living state, Dr. 
 Beale has proposed the term bioplasm for elementary struc- 
 ture while living, and has given a generalization from 
 observed facts which has attracted much attention. He 
 distinguishes in all organic forms three states of matter : 
 First. Germinal matter or bioplasm, or matter which is 
 living. Second. Matter which was living, or formed mate- 
 rial. Third. Matter about to become living, or pabulum. 
 
 Schleiden and Schwann considered the cell as a growth 
 from a nucleus, and to consist of a cell-wall and cavity. 
 In vegetable cells there seemed to be an external wall of 
 cellulose, within which was another, the primordial utri- 
 
THE MICROSCOPE IN BIOLOGY. 119 
 
 cle. But it has since been shown that the appearance of 
 the primordial utricle is caused by the protoplasm or bio- 
 plasm lying in apposition with the inner surface of the 
 cell-wall. In the cryptogamia, cells are known to occur 
 in which no nucleus is visible. Max Schultze and Hackel 
 have also discovered non-nucleated forms of animal life. 
 The idea of nucleus and cell-wall as essential to a cell is 
 therefore abandoned. Nuclei are regarded as new centres 
 of living matter, or minute particles of such matter capa- 
 ble of independent existence. Some of these masses are 
 so small as to be barely visible with the one-fiftieth objec- 
 tive under a magnifying power of five thousand diameters. 
 
 2. The structure and formation of a simple cell may be 
 illustrated by Plate V, Figs. 85 to 89, after Beale.* The 
 earliest condition of such a living particle is shown in 
 Plate V, Fig. 85. If the external membrane of a fully 
 developed spore or any of the growing branches (Plate V, 
 Figs. 86 to 89) be ruptured, such particles would be set 
 free in vast numbers. 
 
 The surface of such a particle becomes altered by con- 
 tact with external agencies. A thin layer of the external 
 surface is changed into a soft membrane or cell-wall, 
 through which pabulum passes and undergoes conversion 
 into living matter, which thus increases. The increase 
 of size is not owing to the addition of new matter upon 
 the external surface, but to the access of new matter in- 
 teriorly. The thickness of the formed material depends 
 on external circumstances, as temperature, moisture, etc. 
 If these be unfavorable to the access of pabulum, layer 
 after layer of living matter will die or be deposited, as in 
 Plate Y, Figs. 87 and 88. If such a cell be exposed to 
 circumstances favorable to growth, the accession of fresh 
 pabulum will cause portions of living matter to make 
 
 * Physiological Anatomy and Physiology of Man, by Drs. Todd, Bow- 
 man, and Beale. New edition. 
 
120 THE MICROSCOPIST. 
 
 their way through natural pores or chance fissures and 
 protrude, as in the figures. 
 
 3. The peculiar phenomena of living cells or bioplasms 
 may be classified as follows: Active or spontaneous move- 
 ment, nutrition and growth, and the power of reproduc- 
 tion. These vital actions, according to Dr. Beale, occur 
 in the bioplasm only, while the formed material, or non- 
 living matter, is the seat of physical and chemical changes 
 exclusively. Physical processes, as diffusion and osmose, 
 occur in bioplasmic particles, but the peculiar phenomena 
 referred to, and which are properly termed vital, do not 
 occur in non-living matter. 
 
 Movements of Cells. Granules imbedded in the bioplasm, 
 either formed material or accidental products, enable our 
 microscopes to observe internal movement, while change 
 of form and of place exhibit the movement of the entire 
 cell. 
 
 The granular movement is either vibratory or continu- 
 ous. The vibrations of the granules appear similar to the 
 molecular movement described by Dr. Robert Brown in 
 1827, and which is common to all small masses of matter, 
 organic or inorganic. Minute cells may thus dance in 
 fluid as well as fine powders, etc. Such movements occur, 
 however, in the interior of living cells, and may possibly 
 be connected with vitality. In the salivary corpuscles, 
 the dancing motion ceases on the addition of a solution 
 of one-half to one per cent, of common salt, while such 
 addition has no influence of the kind on fresh pus or 
 lymph. 
 
 The continuous granular motion is either a relatively 
 slow progression, corresponding to the change of form in 
 the cell, or a swifter flowing movement. Max Schultze 
 thus describes this motion in the threads of sarcode pro- 
 jected from the apertures of a Foramiuiferal shell: "As 
 the passengers in a broad street swarm together, so do 
 the granules in one of the broader threads make their 
 
PLATE V. 
 
 FIG. 85. 
 
 Minute particlesof Bioplasm. From 
 Mildew. ^othin.Obj. 
 
 FIG. 88. 
 
 Passage of Germinal-matter through 
 pores in the formed material. X 1800. 
 
 FIG. 86. 
 
 FIG. 89. 
 
 Production of formed-material on 
 surface of Bioplasm. X 1800. 
 
 Production and accumulation of 
 Formed-material on Bioplasm. Epi- 
 thelium of cuticle. X 700. 
 
 FIG. 87. 
 
 FIG. 90. 
 
 Further production of formed- 
 material. At a is the budding 
 Bioplasm, passing through pores 
 in the formed-material. X 1800. 
 
 Amoeboe from organic infusion. 
 
THE MICROSCOPE IN BIOLOGY. 121 
 
 way by one another, oftentimes stopping and hesitating, 
 yet always pursuing a determinate direction correspond- 
 ing to the long axis of the thread. They frequently be- 
 come stationary in the middle of their course, and then 
 turn round, but the greater number pass to the extreme 
 end of the thread, and then reverse the direction of their 
 movement." Xo physical or chemical action with which 
 we are acquainted will account for such motions, which 
 have no analogy in unorganized bodies. 
 
 Changes of form are most strongly marked in the lower 
 forms of animal life, although occurring also in the sim- 
 pler vegetables, as the volvox. The Amoeba or Proteus is 
 typical of such changes, w T hich have hence been termed 
 Amoeboid (Plate V, Fig. 90). When an Amoeba meets 
 another animal which is too slow to escape, it sends out 
 projections which encircle its prey; these coalesce, and 
 invest the whole mass with its bioplasm. It maintains 
 its grasp till it has abstracted all the portions \vhich are 
 soluble, and then relaxes its hold. 
 
 Amoeboid cells in higher animals rarely move so rapidly 
 as the Amoeba itself. Their motions are limited to a 
 gradual change of form or to the protrusion of processes 
 in the form of threads, or tuberosities, or tufts, which 
 either drag the rest of the body after them or are again 
 withdrawn. 
 
 Cells of bioplasm may not only change their form, but 
 may wander from place to place by protruding a portion 
 of their mass, which drags the rest after it. The discov- 
 ery of wandering cells in the higher organisms, as man, 
 has opened quite a new and important field of physiologi- 
 cal and pathological research. 
 
 The movements of bioplasm may be changed, acceler- 
 ated, retarded, or stopped by a variety of stimuli, mechani- 
 cal, electrical, chemical, and nervous. Gentle warmth and 
 moisture are necessary to their perfection.* 
 
 * See Strieker's Manual of Histology. 
 
122 THE MICROSCOPIST. 
 
 The nutrition and growth of the living cell has already 
 been described as the conversion of pabulum into bioplasm 
 or living matter. The subject of reproduction will be ex- 
 amined below under the head of cell-genesis. 
 
 4. The microscopic demonstration of bioplasm may be 
 effected by the use of an alkaline solution of coloring 
 matter, as carmine. (See Chapter V.) As bioplasm pos- 
 sesses an acid reaction, the alkali is neutralized and the 
 color retained. This process, however, is rather a dem- 
 onstration of the protoplasm which was recently alive. 
 For living cells or bioplasm, we must depend on supplying 
 them artificially with colored food. Thus indigo, carmine, 
 etc., 111 fine particles, added to the pabulum of cells or 
 liquid media in which they float, will be taken into the 
 interior of the bioplasm by the nutritive process. In this 
 way Recklinghausen showed the migration of pus-corpus- 
 cles. 
 
 Welcker and Osborne w r ere the first to use a solution 
 of carmine in order to stain the nuclei of tissues. They 
 were followed by Gerlach and Beale, the latter of whom 
 has greatly improved the process and shown its signifi- 
 cance. 
 
 5. The chemistry of cells and their products is an essential 
 part of biolog}', but would lead us too far from our subject 
 to discuss, yet a few points may not be irrelevant. 
 
 The chemical composition of bioplasm consists essen- 
 tially of oxygen, hydrogen, nitrogen, and carbon. Other 
 elements are often present and important, but not essen- 
 tial. Of the relation of these elements we know nothing, 
 save that they are in a state of constant vibration or 
 change. Dr. Beale considers it doubtful if ordinary chemi- 
 cal combination is possible while the matter lives. Analy- 
 sis in the laboratory is only possible with the compounds 
 resulting from the death of the cell. 
 
 When living or germinal matter is converted into formed 
 material, a combination of its elements takes place, often 
 
THE MICROSCOPE IN BIOLOGY. 123 
 
 with very complex results, the nature of which has hitherto 
 baffled the efforts of chemists to determine. When the 
 life of germinal matter, however, is suddenly destroyed, 
 or rather when the matter is first transformed, the com- 
 pounds resulting from various species have similar chemi- 
 cal composition and properties, and an acid reaction is 
 developed. Fibrin, albumen, water, and certain salts may 
 thus be obtained from every kind of germinal matter. 
 Fatty matters also result, which continue to increase in 
 quantity for some time after death. In slow molecular 
 death, a certain amount of oxygen is taken into combina- 
 tion, which gives rise to different results from those which 
 occur when life is suddenly destroyed. Still other com- 
 binations are due to vital actions which are not yet under- 
 stood.. Thus some bioplasm produces muscle; other par- 
 ticles originate nerve structure, cartilage, bone, connective 
 tissue, etc. Many chemical changes occur also in formed 
 material after its production. It may become dry or fluid, 
 or split up into gaseous or soluble substances as soon as 
 produced. Imperfect oxidation may lead to the formation 
 of fatty matters, uric acid, oxalates, sugar, etc. At the 
 earliest period of development, the formed material con- 
 sists principally of albuminous and fatty matters, with 
 chlorides, alkaline and earthy phosphates. At a later 
 period gelatin, with amyloid or starchy matter, is pro- 
 duced.* 
 
 6. Varieties in the Form and Function of Bioplasm. 
 Mutability of shape is characteristic of amoeboid cells, 
 and no conclusions can be drawn from their appearance 
 after death. Where numbers of them are accumulated, 
 they are flattened by mutual pressure so as to appear 
 polyhedral, laminated, or prismatic. The upper layers of 
 laminated epithelium are usually flattened. Where cells 
 line the interior of cavities in a single layer, they form 
 
 * See Physiological Anatomy, by Todd, Bowman, and Beale. 
 
124 . THE MICROSCOPIST. 
 
 plates of different shape (endothelial cells), or cells in which 
 the long axis predominates (cylindrical epithelium), or 
 forms which are intermediate between plates and cylin- 
 ders. Some cells appear ramified or stellate, as in the 
 cells from the pith of a rush, bone-cells, and corpuscles of 
 the cornea. Others may become extraordinarily elongated, 
 as in the formation of fibre, muscle, etc. Some cells are 
 provided with cilia, which are limited to one portion of 
 the surface, and project their free extremities into the 
 cavity which they line. Dr. Beale considers the cilia to 
 be formed material, and their movements not vital, but a 
 result of changes consequent on vital phenomena. 
 
 Every living organism, plant, animal, or man, begins 
 its existence as a minute particle of bioplasm. Every 
 organic form, leaves, flowers, shells, and all varieties of 
 animals; and every tissue, cellular, vesicular, hair, bone, 
 skin, muscle, and nerve, originates by subdivision and 
 multiplication and change of bioplasm, and the trans- 
 formation or metamorphosis of bioplasm into formed ma- 
 terial. It is evident, therefore, that there are different 
 kinds of bioplasm indistinguishable by physics and chem- 
 istry, but endowed with different powers.* 
 
 7. Cell-Genesis. Schleiden first showed that the em- 
 bryo of a flowering plant originates in a nucleated cell, 
 and that from such cells all vegetable tissues are devel- 
 oped. The original cells were formed in a plasma or blas- 
 tema, commonly found in pre-existing cells, the nuclei first 
 appearing and then the cell-membrane. These views were 
 applied by Schwann to animal structure. The latter be- 
 lieved that the extra-cellular formation of cells, or their 
 origin in a free blastema, was most frequent in animals. 
 The researches of succeeding physiologists have, however, 
 led to a general belief that all cells originate from other 
 cells. 
 
 * Beale's Bioplasm. 
 
THE MICROSCOPE IN BIOLOGY. 125 
 
 The doctrine of spontaneous generation or abiogenesis 
 has been the object of considerable research, but the bril- 
 liant experiments of Pasteur have shown that when all 
 access of living organisms into fluids is prevented, no de- 
 velopment of such organisms can be proved in any case 
 to occur. If the access of air, for instance, to a liquid 
 which has been boiled, is filtered through a plug of cotton- 
 wool, no living forms will appear in the liquid, but on 
 examination, such forms will be found in considerable 
 numbers in the cotton-wool, proving the presence of these 
 forms or their germs in the external air. Recent experi- 
 ments also render it probable that some cell-germs are 
 indestructible by a heat far exceeding that of boiling 
 water. 
 
 There are three forms of cell-multiplication, by fission, 
 by germination or budding, and by internal division. The 
 latter mode is termed endogenous. In it new cells are 
 produced within a parent-cell by the separation of the 
 bioplasm into a number of distinct masses, each of which 
 may become a new cell, as in the fecundated ovum. 
 
 Fission, or the division by cleavage of a parent-cell into 
 two or four parts, may be regarded as a modification of 
 endogenous cell-multiplication. A good example of it 
 may be seen in cartilage. 
 
 Budding or germination consists in the projection of a 
 little process or bud from the mass of bioplasm, which is 
 separated by the constriction of its base, and becomes an 
 independent cell. 
 
 8. Reproduction in the higher organisms consists essen- 
 tially of the production of two distinct elements, a germ- 
 cell or ovum, and a sperm-cell or spermatozoid, by the 
 contact of which the ovum is enabled to develop a new 
 individual. Sometimes these elements are produced by 
 different parts of the same organism, in which case the 
 sexes are said to be united, and the individual is called 
 hermaphrodite, androgynous, or monoecious. In other in- 
 
126 THE MICROSCOPIST. 
 
 stances the sexes are distinct, and the species are called 
 dioecious. 
 
 9. The alternation of generations is a term given in bi- 
 ology to express a form of multiplication which occurs in 
 some of the more simple forms of life. It consists really 
 of the alternation of a true sexual generation with the 
 phenomenon of budding. Thus a fern spore gives rise, by 
 budding and cell-division, to a prothallium ; this produces 
 archegonia and antheridia, as the sexual elements are 
 called, and the embryo which results from sexual union 
 produces not a prothallium but a fern. This phenomenon 
 is better seen in the Hydrozoa. In these the egg produces 
 a minute, ciliated, free-swimming body, which attaches 
 itself, becomes tapering, develops a mouth and tentacles, 
 and is known as the Hydra tuba,. This multiplies itself, 
 and produces extensive colonies by germination, but under 
 certain circumstances divides by fission and produces 
 Medusce, which develop ova. 
 
 10. Parthenogenesis designates the production of new 
 individuals by virgin females without the intervention of 
 a male. It has also been applied to germination and 
 fission in sexless beings. In the Aphides, ova are hatched 
 in spring, but ten or more generations are produced vi- 
 viparously and without sexual union throughout the sum- 
 mer. In autumn, however, the final brood are winged 
 males arid wingless females, from whose union ova are 
 produced in the ordinary manner. 
 
 11. Transformation and metamorphosis relate to certain 
 changes or variations of development in the structure and 
 life history of an individual. Thus an insect is an egg or 
 ovum, a caterpillar or larva, a pupa or chrysalis, and an 
 imago or perfect insect, and these changes of condition 
 and structure constitute its development. Much difficulty 
 is caused by the phenomena of metamorphosis in assign- 
 ing the place of different species, transformations being 
 often mistaken for specific differences. It was formerly 
 
THE MICROSCOPE IN BIOLOGY. 127 
 
 supposed that every animal passed through, in its devel- 
 opment, a series of stages in which it resembled the infe- 
 rior members of the animal scale, and systems of zoology 
 were proposed to be founded on this dream of embryology. 
 Careful research, however, has shown that larval changes 
 present many variations. In some the young exhibit the 
 conditions of adults of lower animals. Thus the Eolis, a 
 univalve shell fish, in its young state has all the charac- 
 teristics of a Pteropod, a free-swimming mollusk. Some- 
 times development is retrograde, and the adult is a de- 
 graded form as compared with the larva, thus setting at 
 nought all our theories, and teaching us that it is better 
 to observe than to imagine. 
 
 12. Discrimination of Living Forms. We have seen, 
 section 6, that there are different kinds of living matter 
 endowed with different powers. We have also seen, sec- 
 tion 7, how varied are the forms of multiplication. Yet 
 when we come to discriminate between animal and vege- 
 table life, we find it exceedingly difficult, especially in 
 their more simple forms. Neither form, nor chemical 
 composition, nor structure, nor motive power, affords suf- 
 ficient grounds for discrimination. Yet when we consider 
 the functions of bioplasm in its varied forms, we may con- 
 veniently group all living beings in three great divisions, 
 viz.,/*m^', plants, and animals. 
 
 The bioplasm of the plant finds its pabulum in merely 
 inorganic compounds, while that of the animal is prepared 
 for it, directly or indirectly, by the vegetable. The func- 
 tion of fungi appears to be the decomposition of the formed 
 material of plants and animals by the means of fermenta- 
 tion or putrefaction, since these latter processes are depen- 
 dent on the presence of fungi. Thus by bioplasm are the 
 structures of plants and animals reared from inorganic 
 materials, and by bioplasm are they broken down and 
 restored to the inanimate world. 
 
128 THE MICROSCOPIST. 
 
 CHAPTER X. 
 
 THE MICROSCOPE IN VEGETABLE HISTOLOGY AND BOTANY. 
 
 HISTOLOGY (from WTOS, a tissue) treats of formed mate- 
 rial, or the microscopic structure resulting from the trans- 
 formation of germinal or living matter. The nature of 
 this transformation is partly physical and partly vital, 
 and, as already stated, is often so complex as to baffle all 
 chemical analysis. Some light, however, has been thrown 
 on this subject by the modification of ordinary crystalline 
 forms when inorganic particles aggregate in the presence 
 of certain kinds of organic matter. To this mode of form- 
 ation the name of molecular coalescence has been given. 
 Mr. Rainey and Professor Harting contemporaneously 
 experimented with solutions of organic colloids, and found 
 that the crystallization of certain lime salts, as the car- 
 bonate, was so modified by such solutions as to resemble 
 many of the calcareous deposits found in nature. These 
 researches leave little doubt but that a majority of calca- 
 reous and silicious organic forms may be thus accounted 
 for. Such changes are rather physical than vital. 
 
 Cell-substance in Vegetables. The protoplasm or bio- 
 plasm in vegetable-cells cannot be distinguished from ani- 
 mal "sarcode" or protoplasm except by the nature of the 
 pabulum or aliment necessary to its nutrition. The vege- 
 table, under the stimulus of light, decomposes carbonic 
 acid, and acquires a red or green color from the compounds 
 which it forms, while the animal requires nutriment from 
 pre-existing organisms. Yet this definition fails to apply 
 to fungi, which resemble primitive animals even in this 
 respect. So difficult is it to discriminate that the simpler 
 forms of vegetables have often been classed by naturalists 
 among animals, and vice versa. Amoeboid movements 
 have been observed in the bioplasm of vegetable-cells, 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 129 
 
 especially in the Volvox, and some have considered it 
 probable that an organism may live a truly vegetable life 
 at one period and a truly animal life at another. 
 
 Analogous to amoeboid movements, is the motion of 
 bioplasmic fluid in the interior of undoubtedly vegetable 
 cells. This movement is called cydosis, and may be de- 
 tected under the microscope by the granules or particles, 
 which the current carries with it in the transparent cells 
 of Chara,VaUisneria, etc., and in the epidermic hairs of 
 many plants, as Tradescantia, Plantago, etc. (Plate VI r 
 Pig. 91). 
 
 The bioplasm of plants may be stained with carmine 
 solution without affecting the cell- wall or other formed, 
 material. 
 
 Cell-wall or Membrane. Plants, whether simple or 
 complicated in structure, are but cells or aggregations of 
 cells. In the simplest vegetables or Protophytes, each cell 
 lives as it were an independent life, performing every 
 function; while in the higher plants, as the palm or oak, 
 the cells undergo special modifications, and serve various 
 functions subsidiary to the life of the plant as a whole. 
 
 Cell-membrane, or the envelope of formed material, was 
 formerly thought to be composed of two layers, to the 
 inner one of which the name of primordial utricle was 
 given, but this is now considered to be but the external 
 surface of the bioplasm or germinal matter. 
 
 The chemical nature of cell-membrane is nearly identi- 
 cal with starch, being composed of cellulose. The presence 
 of cellulose may be shown by the blue color which is 
 produced by applying iodine and sulphuric acid, or the 
 iodized solution of chloride of zinc. 
 
 Endosmose will take place in cell-membrane, allowing 
 solutions to pass through, as pabulum, and the manner of 
 this passage may in some instances determine the subse- 
 quent deposit of formed material. Sometimes actual pores 
 are left in the membrane, as in Sphagnum (Plate YI, Fig. 
 
 9 
 
130 THE MICROSCOPIST. 
 
 92). The walls of vegetable-cells are often thickened by 
 deposit. If this is in isolated patches, the cells are called 
 dotted (Plate VI, Fig. 93), and it is sometimes difficult to 
 distinguish them from porous cells. Many cells have a 
 spiral fibre (Plate VI, Fig. 94), which appears to have 
 Been detached from the outer membrane. In the seeds of 
 Collomia, etc., the cell- wall is less consolidated than the 
 deposit, so that on softening the cells by water, the spiral 
 fibres suddenly spring out, making a beautiful object for 
 a half-inch object-glass (Plate VI, Fig. 95). 
 
 The tendency of formed material to arrange itself in a 
 spiral is seen in the endochrome of many of the simpler 
 plants, as Zygnema,&u(\. the cell-wall sometimes tears most 
 readily in a spiral direction. 
 
 If the spiral deposit is broken and coalesces at some of 
 its turns, it forms an annulus or ring. Some cells show 
 both rings and spirals. 
 
 For the production of a spiral movement or growth, 
 another force is needed in addition to the centripetal and 
 centrifugal forces which are necessary for curvilinear mo- 
 tion. The centripetal point must be carried forward in 
 space by a progressive force. When we consider that a 
 spiral form is so frequently seen in morphology, that the 
 secondary planets move in spirals round their primaries, 
 and that even in distant nebulae the same law prevails, 
 we are struck with the unity of plan which is exhibited 
 throughout the universe, and can scarcely fail to observe 
 that even a microscopic cell shows the tracings of the same 
 divine handiwork which swings the stars in their courses. 
 
 Sclerogen Ligneous Tissue. Sometimes the deposit 
 within the cell-wall is of considerable thickness, and often 
 in concentric rings, through which a series of passages is 
 left so that the outer membrane is the only obstacle to 
 the access of pabulum, as in the stones of fruit, gritty tis- 
 sue of the pear, etc. (Plate VII, Fig. 96). The nature of 
 this deposit is similar to cellulose, although often contain- 
 
PLATE VI. 
 
 FIG. 91. 
 
 FIG. 93.. 
 
 Dotted cells pith of Elder. 
 
 FIG. 94. 
 
 Circulation of fluid in hairs of Tradescanlia 
 Virginiea. 
 
 Spiral cells : A, Balsam ; B, c, 
 Pleurothallis. 
 
 FIG. 92. 
 
 FIG. 95. 
 
 Portion of the leaf of Sphagnum. 
 
 Spiral fibres of seed-coat of Collomin. 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 131 
 
 ing resinous and other matters. Woody fibre or ligneous 
 tissue is quite similar, save that the cells have become 
 elongated or fusiform, and when completely filled up with 
 internal deposit, fulfil no other purpose than that of me- 
 chanical support (Plate VII, Fig. 97). The woody fibres 
 of the Comferce exhibit peculiar markings, which have 
 been called glandular (Plate VII, Fig. 98). In these the 
 inner circle represents a deficiency of deposit as in other 
 porous cells, while the outer circle is the boundary of a 
 lenticular cavity between the adjacent cells. This ar- 
 rangement is so characteristic as to enable us to determine 
 the tribe to which a minute fragment, even of fossil wood, 
 belonged. 
 
 Spiral Vessels. If spiral cells are elongated, or coalesce 
 at their ends, they become vessels, some of which convey 
 air and some fluid (Plate VII, Fig. 99). As in cells, the 
 want of continuity in the spiral fibre sometimes produces 
 rings, when the duct is called annular. In other instances 
 the spires are still more broken up by the process of growth, 
 so as to form an irregular network in the duct, which is 
 then said to be reticulated. A still greater variation in 
 the deposit produces dotted ducts. Xot infrequently we 
 find all forms in the same bundle of vessels. 
 
 Latidferous Vessels (Plate VII, Fig, 100). These con- 
 vey the milky juice or latex of such plants as possess it, 
 as the Euphorbiacese, india-rubber plant, etc., and differ 
 from the ducts above described by their branching, so as 
 to form a network, while ducts are straight and parallel 
 with each other. 
 
 The laticiferous vessels resemble the capillary vessels of 
 animals, while the spiral ducts remind us of the trachea 
 of insects. 
 
 Siliceous Structures. The structures of many plants, 
 especially the epidermis, often become so permeated with 
 a deposit of silica, that a complete skeleton is left after 
 the soft vegetable matter is destroyed. The frustules of 
 
132 THE MICROSCOPIST. 
 
 Diatoms have in this way been preserved in vast numbers 
 in the rocky strata of the earth. The markings on these 
 siliceous shells are so delicate as to be employed as a test 
 of microscopic power and definition. In a species of 
 Equisetum or Dutch rush, silica exists in such abundance 
 that the stems are sometimes employed by artisans as a 
 substitute for sand-paper. If such a stem is boiled and 
 macerated in nitric acid until all the softer parts are de- 
 stroyed, a cast of pure silica will exhibit not only the 
 forms of the epidermic cells, but details of the stomata or 
 pores. The same also is true of the husk of a grain of 
 wheat, etc., in which even the fibres of the spiral vessels 
 are silicified. The stellate hairs of the siliceous cuticle 
 from the leaf of Deutzia scabra forms a beautiful polari- 
 scope object. 
 
 FORMED MATERIAL WITHIN VEGETABLE CELLS. 
 
 1. Raphides. These are crystalline mineral substances, 
 principally oxalate, citrate, and phosphate of lime. They 
 occur in all parts of the plant, sometimes in the form of 
 bundles of delicate needles, sometimes in larger crystals, 
 and sometimes in stellate or conglomerate form. Mr. E. 
 Quekett produced such forms artificially by filling the 
 cells of rice-paper with lime water under an air-pump, and 
 then placing the paper in weak solutions of phosphoric or 
 oxalic acid. 
 
 2. Starch. This performs in plants a similar function 
 to that of fat in animals, and is a most important ingre- 
 dient in human food, since two-thirds of mankind subsist 
 almost exclusively upon it. It is found in the cells of 
 plants in the form of granules or secondary cells. Each 
 granule under the microscope shows at one extremity a 
 circular spot or hilum, around which are a number of 
 curved lines, supposed to be wrinkles in the cell-membrane. 
 When starch is boiled in water, this membrane bursts and 
 
PLATE VII. 
 
 Gritty tissue Pear. 
 
 Spiral vessels : A, reticulated ; B, old 
 vessel, with perforations; c, D, spiral 
 vessels, becoming annular. 
 
 FIG. 100. 
 
 Wood-fibre flax. 
 
 Lactiferous vessels. 
 
 FIG. 98. 
 
 FIG. 101. 
 
 Section of Coniferous Wood in the 
 direction of the fibres. 
 
 m. 
 
 Cubical parenchyma, with stellate cells, 
 from petiole of Nuphar lutea. 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 133 
 
 the amylaceous matter is dissolved. Iodine stains starch 
 blue. Starch shows in the polariscope a black cross in 
 each grain, changing to white as the prism is revolved. 
 
 3. Chlorophyll is the green coloring matter of plants. 
 It is usually seen in the form of granules of bioplasm in 
 the interior of cells. These green granules yield their 
 chlorophyll to alcohol and ether. It seems to be neces- 
 sary to nutrition, since green plants under the stimulus 
 of light break up carbonic acid into oxygen and carbon, 
 the latter of which is absorbed. 
 
 The red and yellow color of autumn leaves is owing to 
 the chemical metamorphosis of chlorophyll, as also is the 
 red color of many of the lower Algae, etc. In the latter 
 it seems to be in some way connected with the vital pro- 
 cesses. 
 
 4. The coloring matter of flowers is various, and ordinarily 
 depends on the colored fluid contained in cells subjacent 
 to the epidermis, although sometimes it is in the form of 
 solid corpuscles. White patches on leaves, etc., arise from 
 absence of chlorophyll. 
 
 5. Milky juices are true secretions contained in the lati- 
 ciferous ducts. The juice of the dandelion, caoutchouc 
 or india-rubber, which is the concrete juice of the Ficus 
 elastica, and gutta-percha, from Isonandra gutla, are exam- 
 ples. 
 
 6. Fixed oils are found in the cells of active tissues, and 
 notably in seeds, w r here they serve to nourish the embryo. 
 Cocoauut, palm, castor, poppy, and linseed oils are exam- 
 ples. 
 
 7. Volatile oil, sometimes called essential oil, is chiefly 
 found in glandular cells and hairs of the epidermis. 
 Many of them yield a resinous substance by evaporation. 
 
 8. Camphor is analogous to volatile oil, although solid 
 at ordinary temperatures. It abounds in the Lauracese. 
 
 9. Resin, wax, and tallow are also found in plants. The 
 bloom of the plum and grape is due to wax. 
 
134: THE MICROSCOPIST. 
 
 10. Gum is a viscid secretion. What is called gum 
 tragacanth, is said to be partially decomposed cell-mem- 
 brane, and is allied to amyloid matter. 
 
 Forms of Vegetable Cells. From the account given in 
 the chapter on biology, page 123, it is evident that the 
 form of cells is quite varied, and often depends on the 
 amount of pressure from aggregation, yet function also 
 has much to do in the determination of shape. Thus 
 while most elongated cells are lengthened in the direction 
 of plant-growth, in which is least resistance, the medul- 
 lary rays of Exogenous stems are elongated in a horizon- 
 tal direction. Some cells are cubical, as in the leaves of 
 the yellow water-lily, Nuphar lutea (Plate VII, Fig. 101). 
 Others are stellate, as in the rush (Plate VIII, Fig. 102). 
 In many tissues are large cavities or air-chambers alto- 
 gether void of cells, and in leaves such cavities communi- 
 cate with the external air by means of stomata or pores 
 (Plate VIII, Fig. 103), which are usually provided with 
 peculiar cells for contracting or widening the orifice. 
 
 The Botanical Arrangement of Plants. Considered with 
 reference to their general structure, plants are divided by 
 botanists into cellular and vascular. The first of these 
 classes is of greatest interest to the microscopist, as em- 
 bracing the minuter forms of vegetable life. 
 
 The classification and natural grouping of plants is yet 
 far from being perfect, although microscopic examinations 
 have largely contributed to an orderly arrangement of the 
 multitudinous varieties in this field of research. In the 
 present work w r e propose only a brief outline of typical 
 subjects of interest, with the methods of microscopic ex- 
 amination. 
 
 Fungi. At page 127 it was stated that all living beings 
 may be grouped in three divisions, fungi, plants, and 
 animals. Botanists generally class fungi among cellular 
 flowerless plants. They cannot assimilate inorganic food 
 as other plants, but live upon the substance of animal or 
 
PLATE VIII. 
 
 FIG. 102. 
 
 Section of cellular parenchyma of Rush. 
 
 Portion of the cuticle of the leaf of the Irix 
 Germanica, torn from its surface. 
 
 FIG. 104. 
 
 Cells from the petal of the Geranium 
 (Pelargonium). 
 
 :-, - < 
 
 Cuticle of leaf of Indian Corn (Zea mats). 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 135 
 
 vegetable tissue. They also differ from ordinary vegeta- 
 bles by the total absence of chlorophyll or its red modifi- 
 cation. A large number of this strange class are micro- 
 scopic, and require high powers for their observation. 
 Eecent investigations show that individual fungi are de- 
 veloped in very dissimilar modes, and are subject to a 
 great variety of form, rendering it probable that those 
 which seem most simple are but imperfectly developed 
 forms. Amoeboid motions also in the cell-substance of 
 certain kinds of fungi, and the projection of threads of 
 bioplasm, show a great resemblance to some of the lower 
 forms of animal life, as the Rhizopods. 
 
 All fungi exhibit two well-defined structures, a myce- 
 liuin or vegetative structure, which is a mass of delicate 
 filaments or elongated cells; and a, fruit or reproductive 
 structure, which varies in different tribes. In Tonda, one 
 or more globular cells are produced at the ends of fila- 
 ments composed of elongated cells ; these globules drop 
 off and become new mycelia. The " yeast plant," or Torula 
 cerevisia (Plate IX, Fig. 107), receives its name from its 
 habitat. Fermentation depends upon its presence, as pu- 
 trefaction does upon the minute analogous bodies called 
 Bacteria and Vibriones. Bacteria are minute, moving, 
 rod-like bodies, sometimes jointed ; and vibriones are 
 moniliform filaments, having a vibratile or wriggling: mo- 
 
 O SO O 
 
 tion across the field of view in the microscope. The re- 
 searches of Madame Luders render it probable that the 
 germs of fungi develop themselves into these bodies when 
 sown in water containing animal matter, and into yeast 
 in a saccharine solution. The universal diffusion of spor- 
 ules of fungi in the atmosphere readily accounts for their 
 appearance in such fluids, and Pasteur's experiments are 
 quite conclusive. 
 
 The minute molecules called microzymes, present in va- 
 rious products of disease, as the vaccine vesicle, fluid of 
 glanders, etc. ; the minute corpuscles which cause the dis- 
 
136 THE MICROSCOPIST. 
 
 ease among silkworms called "pebrine;" etc.; have a 
 strong analogy in their rapid multiplication to the yeast- 
 cells. * 
 
 The sporules of any of the ordinary moulds, as Penicil- 
 lium, Mucor, or Aspergillus, will develop into yeast-cells 
 in a moderately warm solution of cane-sugar, showing 
 how differently the same type of bioplasm may develop 
 under different conditions. The term polymorphism has 
 been given to this phenomenon. Very many species, and 
 even genera, so called, may after all be only varieties of 
 the same kind of organism. 
 
 In many morbid conditions of the skin and mucous 
 membranes, there is not only an alteration or morbid 
 growth of the part, but a vegetation of fungi. Thrown- 
 off scales of epithelium from the mouth and fauces exhibit 
 fibres of leptothrix, and the false membrane of diphtheria, 
 as well as the white patches of aphtha or thrush, show 
 the mycelia and spores of fungi. The disease in silkworms 
 called muscardiue is due to a fungus, the Botrytis bassiana 
 (Plate VIII, Fig. 104), whose spores enter and develop in 
 the air-tubes. The filamentous tufts seen about dead flies 
 on window-panes, etc., arise from a similar growth of 
 Achyla. In certain Chinese or Australian caterpillars, 
 this sort of growth becomes so dense as to give them the 
 appearance of dried twigs. Even shells and other hard 
 tissues may become penetrated by fungi. The dry rot in 
 timber is a form of fungus. 
 
 The mildew which attacks the straw T of wheat, etc., 
 arises from the Puccinia graminis, whose spores find their 
 way through the stomata or breathing pores of the epi- 
 dermis. Rust, and smut, and bunt, originate in varieties 
 of Uredo. The "vine disease" and the "potato disease," 
 as they are called, have similar origin. 
 
 Various methods have been proposed to destroy fungi 
 in growing plants, but it must be remembered that the 
 function of these organisms is chiefly to remove formed 
 
PLATE IX. 
 
 FIG. 107. 
 
 
 o 
 
 Q 
 
 Torula Cerevisice, or Yeast-Plant. 
 
 FIG. 108. 
 
 FIG. 109. 
 
 Germ and Sperm-cells in Acbyla. 
 
 Eevelopmcnt of fungi: A, myceliiim; B, hypha; c, conidiophores ; D, a magnified branch. 
 
 FIG. 110. 
 
 B I * , f ; , 
 
 Various phases of development of Palmoglcea macrococca. 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 137 
 
 material in a state of decay, which is more or less com- 
 plete. The prevalence of atmospheric changes, variations 
 in light, heat, moisture, and electricity, etc., have much 
 to do in predisposing vegetable as well as animal tissues to 
 disease and producing epidemics. The agriculturist, there- 
 fore, as well as the physician, must discriminate between 
 those diseased conditions which provide a habitat for 
 fungi, and the effects produced by the fungi themselves. 
 
 Impregnating wood with corrosive sublimate or chlo- 
 ride of zinc has been used to prevent dry rot in wood, and 
 soaking seeds in alkaline solutions or sulphate of copper 
 is said to remove smut and similar fungus spores. 
 
 The development of fungi is from spores or conidia. 
 Plate IX, Fig. 107, represents the Torula vegetating by 
 the budding of its spores. These buds rapidly fall off and 
 become independent cells. In other varieties self-division 
 gives rise to the myceliam, a mass of fibres often inter- 
 laced so as to form a sort of felt. Some branches of this 
 mycelium (hyphce] hang down, while others rise above the 
 surface (conidiophores) and bear conidia, which fall off and 
 develop into new hyphse (Plate IX, Fig. 108). In the 
 "blight" of the potato the mycelium is loose, and the 
 hyph?e ramify in the intercellular spaces and give off pro- 
 jections into the cells of the plant. The conidia germinate 
 by bursting the sac which contains them, putting forth 
 cilia, moving awhile, then. resting and enveloping thera- 
 selveS with membrane and growing into hyphse. In the 
 autumn, parts of the hyphae assume special functions. 
 One part develops a spherical mass called oogonium, while 
 another becomes a smaller mass or antheridium. When 
 the first is ripe, it is penetrated by the latter, and the 
 bioplasms of each are fused together. The antheridium 
 then decays, while the oogonium grows and becomes au 
 oospore, in which the bioplasm divides and subdivides. 
 Xext season each segment escapes ciliated, and moves 
 about till it finds a place to germinate. In Achyla two 
 
138 THE MICROSCOPIST. 
 
 sacs are formed, one of which contains "germ-cells," and 
 the other anther ozoids or "sperm-cells." When both are 
 ripe the sac opens, and the ciliated antherozoids pass into 
 the neighboring sac and fertilize its contents (Plate IX, 
 Fig. 109). 
 
 In other fungi the reproductive cells are undistinguish- 
 able from the rest, and the coalescence takes place in a 
 new cell formed by the union of the other two. 
 
 Mr. Berkeley divides fungi into six orders, as follows : 
 
 1. Hymenomycetes or AgaricoidecB (Mushrooms, etc.). 
 Mycelium flocuose, inconspicuous, bearing fleshy fruits 
 which expand so as to expose the hymenium or sporifer- 
 ous membrane to the air. Spores generally in fours on 
 short pedicles. 
 
 2. Gasteromycetes or Lycoperdoidece (Puff balls, etc.). 
 Fruit globular or oval, with convolutions covered by the 
 hymenium, which bears the spores in fours on distinct 
 pedicles. The convolutions break up into a pulverulent 
 or gelatinous mass. 
 
 3. Coniomycetes or Uredoidece (Smuts, etc.). Mycelium 
 filamentous, parasitic. Microscopic fructification of ses- 
 sile or stalked spores in groups, sometimes septate. 
 
 4. Hyphomycetes or BotrytoideaR (Mildews, etc.). Micro- 
 scopic. Mycelium filamentous, epiphytic, with erect fila- 
 ments bearing terminal, free, single, simple, or septate 
 spores. 
 
 5. Ascomycetes or Selvelloidece (Truffles, etc.). Myce- 
 lium inconspicuous. Fruit fleshy, leathery, horny, or ge- 
 latinous, lobed, or warty, with groups of elongated sacs 
 (asci or theece) in which the spores (generally eight) are 
 developed. 
 
 6. Physomycetes or Mucoroidece (Moulds). Mycelium 
 (microscopic) filamentous, bearing stalked sacs containing 
 numerous minute sporules. 
 
 Protophytes, or primitive plants, afford many forms and 
 groups of great interest to the microscopist as well as to 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 139 
 
 the biologist. "The plan of the present work permits us 
 only to indicate a few particulars, the details of which 
 would form a volume of considerable size. 
 
 The Algae are divided into three orders: I. Rhodosper- 
 meoe or Florida (Red-spared Algce). Marine plants, with 
 a leaf-like or filamentous rose-red or purple thallus. II. 
 Melanosporece or Fucoidece (Dark-spored Algae). Marine. 
 Thallus leaf-like, shrubby, cord-like, or filamentous, of 
 olive-green or brown color. III. Chlorosporece or Confer- 
 voidece (Green-spored Algce). Plants marine or fresh water, 
 or growing on damp surfaces. Thallus filamentous, rarely 
 leaf-like, pulverulent, or gelatinous. These have been 
 subdivided into families, viz. : 
 
 I. Rhodospermeoe. 1. Rhodomelaceae. 2. Laurenciaceae. 
 3. Corallinaceae. 4. Delesseriaceae. 5. Rhodymeniaceae. 
 6. Cryptonemiaceae. 7. Ceramiaceae. 8. Porphyraceae. 
 
 II. Melanosporece. 1. Fucaceae. 2. Dictyotaceae. 3. 
 Cutleriaceae. 4. Laminariaeeae. 5. Dictyosiphonaceae. 6. 
 Punctariacese. 7. Sporochnacese. 8. Chordariacese. 9. 
 Myrionemace83. 10. Ectocarpaceae. 
 
 III. Chlorosporece. 1. Lemaneese. 2. Batrachospermeea. 
 3. Cho3tophorace8e. 4. Confervace^e. 5. Zygnemaceae. 
 6. (Edogoniacese. 7. Siphonaceee. 8. Oscillatoriaceae. 9. 
 Xostochacese. 10. Ulvaceae. 11. Palmellaceea. 12. Des- 
 midiaceae. 13. Diatomacese. 14. Yolvocineea. 
 
 For fuller information, we refer to the Micrographic 
 Dictionary by Griffith and Henfrey. 
 
 In the family of Palmellacece we find the simplest forms 
 of vegetation in the form of a powdery layer of cells, or a 
 slimy film, or a membranous frond. The green mould on 
 damp walls and the red snow of alpine regions are exam- 
 ples. 
 
 In the green slime on damp stones, etc., is found the 
 Pcdmoglcea macrococca. The microscope shows it to con- 
 sist of cells containing chlorophyll, surrounded by a ge- 
 latinous envelope. These cells multiply by self-division. 
 
140 THE MICROSCOPIST. 
 
 Sometimes a conjugation or fusion of cells occurs, and the 
 product is a spore or primordial cell of a new generation 
 (Plate IX, Fig. 110). During conjugation oil is produced 
 in the cells, and the chlorophyll disappears or becomes 
 brown, and when the spore vegetates, the oil disappears 
 and green granular matter takes its place. This is analo- 
 gous to the transformation of starch into oil in the seeds 
 of the higher plants. 
 
 Most of the lower forms of vegetable life pass through 
 what is called the motile condition, which depends on the 
 extension of the bioplasm into thread-like filaments, whose 
 contractions serve to move the cell through the water. 
 Many of these forms were formerly mistaken for animal- 
 cules, and the transformation of a portion of green chlo- 
 rophyll into the red form was represented as an eye. The 
 multiplication of the "still" cells is by self-division, as in 
 Palmoglcea, but after this has been repeated about four 
 times, the new cells become furnished with cilia and pass 
 into the "motile" condition, and their multiplication goes 
 on in different ways, as by binary or quaternary segmen- 
 tation, or the formation of a compound, mulberry-like 
 mass, the ciliated individual cells of which, becoming free, 
 rank as zoospores (Plate X, Fig. 111). 
 
 The Volvox is a beautiful example of the composite 
 motile form of elementary vegetation. It is found in 
 fresh water, and consists of a hollow pellucid sphere, 
 studded with green spots, connected together often by 
 green threads. Each of these spots has two cilia, whose 
 motions produce a rolling movement of the entire mass. 
 Within the sphere there are usually from two to twenty 
 smaller globes, which are set free by the bursting of the 
 original envelope. Sometimes one of the masses of endo- 
 chrome enlarges, but instead of undergoing subdivision 
 becomes a moving mass of bioplasm, which cannot be dis- 
 tinguished from a true Amoeba or primitive animal cell. 
 
 The Desmidiacece are a family of minute green plants 
 
PLATE X. 
 
 FIG. 111. 
 
 Various phases of development of Protococcus pluvialis. 
 
 FIG. 112. 
 
 <=/ ^ <* 
 
 f 
 
 Formation of Zoospores in Phycoseris gfgantea(Ulva latissima). 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 141 
 
 of great interest. Generally the cells are independent, 
 but a filament is sometimes formed by binary subdivision. 
 Their symmetrical shape, and frequently spinous projec- 
 tions and peculiar movements, render them beautiful ob- 
 jects. By conjugation a spore-cell or sporangium is pro- 
 duced, which in some species is spinous, and resembles 
 certain fossil remains in flint, which have been described 
 as animalcules under the name of Xanthidia. 
 
 The family of Diatomacece affords more occupation to 
 microscopists than other protophytes. Like the Desmids, 
 they are simple cells with a firm external coating, but in 
 Diatoms this coating is so penetrated with silex, that a 
 cast of the frustule is left after the removal of the organic 
 matter. Reference has already been made to the number 
 of these organisms in a fossil state, as well as to their 
 utility as tests of the defining power of microscopic object- 
 glasses. 
 
 Some species inhabit the s*ea, and others fresh water. 
 They are so numerous that scarcely a ditch or cistern is 
 free from specimens, and they multiply so rapidly as to 
 actually diminish the depth of channels and block up 
 harbors. They may be sought for in the slimy masses 
 attached to rocks and plants in water, in the scum of the 
 surface, in mud or sand, in guano, in the stomachs of 
 molluscs, etc., and on sea-weeds. 
 
 To separate the shields or siliceous frustules from foreign 
 matter, either fresh or fossil, they should be washed sev- 
 eral times in water, and the sediment allowed to subside. 
 The deposit should then be treated in a test-tube with 
 hydrochloric acid, sometimes aided by heat. This should 
 be repeated as often as any effect is produced, and then 
 the sediment should be boiled in strong nitric acid, and 
 washed several times in water. They may be mounted 
 dry or in balsam. 
 
 The classification of Diatoms is not yet perfected, but 
 Mailer's type slides, containing from one hundred to five 
 
142 THE MICROSCOPIST. 
 
 hundred characteristic forms, is a valuable assistance. 
 The following table, from the Micrographic Dictionary, 
 gives an analysis of tribes and genera : Fr. denotes the 
 frustules in front view; v. the valves; granular striae 
 means striae resolvable into dots ; and continuous striae 
 signify costae or canaliculae. 
 
 A. Frustules not contained in a Gelatinous Mass or Tube. 
 
 TRIBE I. STRIAT.E. Frustules usually transversely stri- 
 ate, but neither vittate nor areolate. 
 
 t Valves without a Median Nodule. 
 
 COHORT 1. EUNOTIEJE. Fr. arcuate, single, or united 
 into a straight filament. 
 
 1. Epithemia. Fr. single or binate, with transverse or 
 slightly radiant striae, some continuous ; no terminal nod- 
 ules; aquatic and marine. 
 
 2. Eanotia. Fr. single or binate; v. with slightly ra- 
 diant granular striae and terminal nodules; aquatic. 
 
 3. Himantidium,. Fr. as in Eanotia, but united into a 
 filament; striae parallel, transverse; aquatic. 
 
 COHORT 2. MERIDE.E. Fr. cuneate, single, or united 
 into a curved or spinal band; v. with continuous or gran- 
 ular striae. 
 
 4. Meridian. Fr. cuneate, united into a spiral band; 
 striae continuous ; aquatic. 
 
 5. Eueampia. Fr. united into an arched band; v. punc- 
 tate; marine. 
 
 6. Oncosphenia. Fr. single, cuneate, uncinate at the 
 narrow end; striae granular; aquatic. 
 
 COHORT 3. FRAGILLARIE^:. Fr. quadrilateral, single, or 
 united into a filament or chain ; v. with continuous or 
 granular striae. 
 
 7. Diatoma. Fr. linear or rectangular, united by the 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 143 
 
 angles so as to form a zigzag chain; striae continuous; 
 aquatic and marine. 
 
 8. Asterionella. Fr. adherent by adjacent angles into 
 a star-like filament; v. inflated at one or both ends; 
 aquatic. 
 
 9. Fragillaria. Fr. linear, united into a straight, close 
 filament ; striae granular, faint ; aquatic and marine. 
 
 10. Denticula. Fr. linear, simple, or binate, rarely more 
 united; striae continuous; aquatic. 
 
 11. Odontidium. As Denticula, but fr. forming a close 
 filament ; aquatic and marine. 
 
 COHORT 4. MELOSIRE^:. Fr. cylindrical, disk-shaped or 
 globose; v. punctate, or often with radiate continuous 
 or granular striae. 
 
 12. Cydotdla. Fr. disk-shaped, mostly solitary; v. 
 with radiate marginal striae ; aquatic. 
 
 13. Melosira. Fr. cylindrical or spherical, united into 
 a filament; v. punctate, or with marginal radiate granu- 
 lar striae ; aquatic and marine. 
 
 14. Podosim. Fr. united in small numbers, cylindrical 
 or spherical, fixed by a terminal stalk; v. hemispherical, 
 punctate; marine. 
 
 15. Mastogonia. Fr. single; v. unequal, angular, mam- 
 miform, circular at base, without umbilical processes ; 
 angles radiating; fossil. 
 
 16. Pododiscus. Fr. single or united, with a marginal 
 stalk ; v. circular, convex. 
 
 17. Pyxidicula. Fr. single or binate, free or sessile ; 
 v. convex ; aquatic and marine. 
 
 18. Stephanodiscus. Fr. single, disk-shaped; v. circu- 
 lar, equal, punctate, or striate, with a fringe of minute 
 marginal teeth ; aquatic. 
 
 19. Stephanogonia. Fr. as in Mastogonia, but ends of 
 valves truncate, angular, and spinous; fossil. 
 
 20. Hercotheca. Fr. single, turgid laterally ; v. with 
 marginal free setae. 
 
144 THE MICROSCOPIST. 
 
 21. Goniothecium. JBY. single, constricted in the middle, 
 suddenly attenuate and truncate at the ends (hence appear- 
 ing angular). 
 
 COHORT 5. SURIRELLE.E. Fr. single or binate, quadri- 
 lateral, oval, or saddle-shaped, sometimes constricted in 
 the middle; v. with transverse or radiating continuous 
 or granular striae, interrupted in the middle, or with one 
 or more longitudinal rows of puncta; often keeled. 
 
 22. Bacillaria. Fr. prismatic, straight, at first forming 
 a filament; v. with a median longitudinal row of puncta; 
 marine. 
 
 23. Campylodisciis. Fr. single, free, disk-shaped; v. 
 curved or twisted (saddle-shaped); aquatic and marine. 
 
 24. Doryphora. Fr. single, stalked; v. .lanceolate or 
 elliptical, with transverse granular striae. 
 
 25. Podocystis. Fr. attached, sessile; v. with a median 
 line, transverse continuous, and intermediate granular 
 striae. 
 
 26. Nitzschia. Fr. free, single, compressed, usually elon- 
 gate, straight, curved, or sigmoid, with a not-median 
 keel, and one or more longitudinal rows of puncta ; 
 aquatic and marine. 
 
 27. Sphinctocystis (Cymato pleura). Fr. free, single, linear, 
 with undulate margins; v. oblong or elliptical, sometimes 
 constricted in the middle; aquatic. 
 
 28. Surirella. Fr. free, single, ovate, elliptical, oblong, 
 cuneate, or broadly linear; v. with a longitudinal median 
 line or clear space, margins winged, and with transverse 
 or slightly radiating continuous striae ; aquatic and marine. 
 
 29. Synedra. Fr. prismatic, rectangular, or curved ; at 
 first attached to a gelatinous-lobed cushion, often becom- 
 ing free; v. linear or lanceolate, usually with a median 
 pseudo-nodule and longitudinal line ; aquatic and marine. 
 
 30. Tryblionella. Fr. free, linear, or elliptical ; v. plane, 
 with a median line, transverse striae, and submarginal or 
 obsolete alae ; aquatic and marine. 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 145 
 
 31. Raphoneis. Doryphora without a stalk. 
 
 COHORT 6. AMPHIPLEURE.E. Fr. free, single, straight, 
 or slightly sigrnoid ; v. lanceolate, or linear-lanceolate, 
 with a median longitudinal line. 
 
 32. Amphipleura. Characters as above. 
 
 ft Valves with a Median Nodule. 
 
 COHORT 7. COCCONEIDJI;. Fr. straight or hent, attached 
 by the end or side ; v. elliptical, equilateral. 
 
 33. Cocconeis. Fr. single, compressed, adnate; v. ellip- 
 tical, one of them with a median line. 
 
 COHORT 8. ACHXANTHE^:. Fr. compressed, single, or 
 rarely united into a straight filament, curved, attached 
 by a stalk at one angle; uppermost v. with a longitudinal 
 median line, lower v. the same, and a stauros or transverse 
 line; marine. 
 
 35. Achnanthidium. Fr. those of Achnanthes, but free ; 
 aquatic. 
 
 36. Cymbosira. Fr. as Achnanthes, solitary or binate, 
 stipitate, and attached end to end ; marine. 
 
 COHORT 9. CYMBELLE^E. Fr. straight or curved, free or 
 stalked at the end ; v. inequilateral, not sigmoid. 
 
 37. Cymbella. Fr. free, solitary; v. navicular, with. a 
 subcentral and two terminal nodules, and a submedian 
 longitudinal line; aquatic. 
 
 38. Cocconema. Fr. as Cymbella, but stalked; aquatic. 
 COHORT 10. GOMPHOXEMEJE.' Fr. wedge-shaped, straight, 
 
 free, or stalked ; v. equilateral. 
 
 39. Gomphonema. Fr. single or binate, wedge-shaped, 
 attached by their ends to a stalk ; v. with a median line, 
 and a median and terminal nodules; aquatic. 
 
 40. Sphenella. Fr. free, solitary, wedge-shaped, invo- 
 lute; aquatic. 
 
 10 
 
146 THE MICROSCOPIST. 
 
 41. Sphenosira. Fr. united into a straight filament; v. 
 wedge-shaped, at one end rounded, suddenly contracted 
 and produced ; aquatic. 
 
 COHORT 11. NAVICULE^;. Fr. free, straight; v. equilat- 
 eral, or sometimes sigmoid. 
 
 42. Navicula. Fr. single, free, straight ; v. oblong, lan- 
 ceolate, or elliptical, with a median line, a central and two 
 terminal nodules, and transversely or slightly radiant lines 
 resolvable into dots ; aquatic, marine, and fossil. 
 
 43. Gyrosigma (Pleurosigma). Fr. as Navicula, but v. 
 .sigmoid ; aquatic and marine. 
 
 44. Pinnularia. Fr. as Navicula, but transverse lines 
 continuous ; aquatic and marine. 
 
 45. tStauroneis. Fr. a8 Navicula, but the median line 
 replaced by a stauros; aquatic and marine. 
 
 46. Diadesmis. Fr. as Navicula, united into a straight 
 filament; aquatic. 
 
 47. Amphiprora. Fr. free, solitary, or in pairs, con- 
 stricted in the middle; v. with a median keel, and a 
 median and terminal nodules, often twisted ; marine. 
 
 48. Amphora. Fr. plano-convex, elliptical, oval or ob- 
 long, solitary, free or adnate, with a marginal line, and a 
 nodule or stauros on the flat Bide ; aquatic and marine. 
 
 TRIBE II. VITTATJE. Fr. with vittse. 
 
 f Valves without a Median Nodule. 
 
 COHORT 12. LICMOPHORE^:. Fr. cuneate; vittae arched. 
 
 49. Licmophora. Fr. cuneate, rounded at the broad 
 end, radiating from a branched stalk ; vittse curved (by 
 inflection of upper margins of valves) ; marine. 
 
 50. Podosphenia. Fr. as Licmophora, but single or in 
 pairs, sessile on a thick but little branched pedicle; ma- 
 rine. 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 147 
 
 51. Rhipidophora. Fr. as Licmophora, single or in pairs, 
 on a branched stipes ; marine. 
 
 52. Climacosphenia. Fr. cuneate, rounded at broad end, 
 divided into loculi by transverse septae or vittae ; marine. 
 
 COHORT 13. STRIATELLE.E. Fr. tabular or filamentous; 
 vittae straight (not arched). 
 
 53. Striatella.'Fr. compound, stalked at one angle; 
 vittae longitudinal and continuous ; v. elliptic-lanceolate, 
 not striated ; marine. 
 
 54. jRhabdonema. Fr. as Striatdla, but vittae inter- 
 rupted ; v. with transverse granular striae ; marine. 
 
 55. Tetraeydus. Fr. compound, filamentous ; vittae al- 
 ternate, interrupted ; v. inflated at the middle ; striae trans- 
 verse, continuous ; aquatic. 
 
 56. Tabellaria. Fr. united into a filament, subsequently 
 breaking up into a zigzag chain ; vittae interrupted, alter- 
 nate ; v. inflated at middle and ends ; aquatic. 
 
 57. Pleurodesmium.FT. tabular, united into a filament, 
 and with a transverse median hyaline band; marine. 
 
 58. Hyalosira. Fr. tabular, fixed by a stalk at one 
 angle ; vittae alternate, interrupted, bifurcate at the end ; 
 marine. 
 
 59. Anaulus. Fr. rectangular, single, compressed, with 
 lateral inflections, giving the valves a ladder-like appear- 
 ance ; marine. 
 
 60. Biblarium. Fr. as Tetmcydiis, but single ; fossil. 
 
 61. Terpsinoe. Fr. tabular, obsoletely stalked, subse- 
 quently connected by isthmi ; vittae transverse, short, in- 
 terrupted, and capitate ; aquatic and marine. 
 
 62. Stylolihlium. Fr. compound ; v. circular, sculptured 
 with continuous striae ; fossil. 
 
 ft With a Median apparent (pseudo) Nodule. 
 63. Orammatophora. Fr. at first adnate, afterwards 
 
148 THE MICROSCOPIST. 
 
 forming a zigzag chain ; vittse two, longitudinal, inter- 
 rupted, and more or less figured ; marine. 
 
 TKIBE III. AREOLATJE. Yalves circular, with cell-like 
 (areolar) markings, visible by ordinary illumination. 
 
 SUB-TRIBE 1. DISCIFORMES. Yalves alike, without ap- 
 pendages or processes. 
 
 COHORT 14. COSCINODISCE^I. Valves circular. 
 
 64. Actinocychis. Fr. solitary; v. circular, undulate, 
 the raised portions like rays or bands radiating from the 
 centre, which is free from markings ; marine and fossil. 
 
 65. Actinoptychus. Fr. as Actinocydus, but radiating 
 internal septee, as well as rays. 
 
 66. Cosdnodiscus. Fr. single ; v. circular, areolar all 
 over ; marine and fossil. 
 
 67. Arachnoidiscus. Fr. single ; v. circular, not undu- 
 late, with concentric and radiating lines, and intermediate 
 areola absent from the centre (pseudo-nodule) ; marine 
 and fossil. 
 
 68. Asterolampra. Fr. single ; v. circular, finely areolar, 
 except in the centre and at equidistant clear marginal rays 
 radiating from the centre, which is traversed by radiating 
 dark lines (septa), alternating with the marginal rays ; 
 fossil. 
 
 69. Aster omphalos. As Asterolampra, but two of the 
 central dark lines parallel, and the corresponding mar- 
 ginal ray obliterated ; fossil. 
 
 70. Halionyx. Fr. single ; v. circular, without septa, 
 with rays not reaching the centre, and with intermediate 
 shorter rays ; between the rays transverse areolar lines ; 
 fossil. 
 
 71. Odontodiscus. Fr. single, lenticular ; v. covered 
 with puncta (areolae), arranged in radiating rows on ex- 
 centrically curved lines, and with erect marginal teeth ; 
 fossil. 
 
 72. Omphalopelta. As Actinoptychus, but upper part of 
 margin of valves with a few erect spines ; fossil. 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 149 
 
 73. Symbolophora. Fr. single, disk-shaped ; v. with in- 
 complete septa radiating from the solid angular umbili- 
 cus, and intermediate bundles of radiating lines ; marine 
 and fossil. 
 
 74. Systephania. Fr. single ; v. circular, areolar, with- 
 out rays or septa, with a crown of spines or an erect 
 membrane on the outer surface of each valve ; fossil. 
 
 COHORT 15. ANGULIFERA. Valves angular. 
 
 75. Amphitetras. Fr. at first united, afterwards sepa- 
 rating into a zigzag chain, rectangular; v. rectangular, 
 the angles often produced ; marine. 
 
 76. Amphipentras. Fr. solitary ; v. pentangular ; fossil. 
 
 77. Lithodesmium. Fr. united into a straight filament ; 
 v. triangular, one side plane, the others undulate ; marine. 
 
 TRIBE IY. APPENDICULAT.E. Valves with processes or 
 appendages, or with the angles produced or inflated. 
 COHORT 16. EUPODISCE^:. Fr. disk-shaped; v. circular. 
 
 78. JEupodiscus. Fr. single, disk-shaped ; v. circular, 
 with tubular or horn-like processes on the surface ; aquatic 
 and marine. 
 
 79. Auliscus. As Eupodiscus, but processes obtuse and 
 more solid ; fossil. 
 
 80. Insilella. Fr. single, fusiform ; v. equal, with a 
 median turgid ring between them ; marine. 
 
 COHORT 17. BIDDULPHIE^:. Fr. flattened; v. elliptical 
 or suborbicular. 
 
 81. Biddulphia. Fr. rectangular, more or less united 
 into a continuous or zigzag filament; the angles inflated 
 or produced into horns ; v. convex, centre usually spinous ; 
 marine. 
 
 82. Isthmia. Fr. rhomboidal or trapezoidal, cohering 
 by one angle ; angles produced ; marine. 
 
 83. Chcetoceros. Fr. compressed ; v. equal, with a long 
 spine or filament on each side ; marine. 
 
150 THE MICROSCOPIST. 
 
 84. Ehizoselenia. Fr. elongate, subcylindrical, marked 
 with transverse or spiral lines, ends oblique or conical, 
 and with one or more terminal bristles ; marine. 
 
 85. Hemiaulus. Fr. single, compressed, rectangular; 
 angles produced into tubular direct processes, those on 
 one valve longer than on the other ; fossil. 
 
 86. Syringidium. Fr. single, terete, acuminate at one 
 end, two-horned at the other ; marine. 
 
 87. Periptera. Fr. single, compressed ; v. unequal, one 
 simply turgid, the other with marginal wings or spines ; 
 fossil. 
 
 88. Dicladia. Fr. single; v. unequal, one turgid and 
 simple, the other two-horned ; fossil. 
 
 COHORT 18. ANGULAT^. Valves angular. 
 
 89. Triceratium. Fr. free ; y. triangular, each angle 
 with a minute tooth or horn ; marine. 
 
 90. Syndendrium. Fr. single, subquadrangular ; v. un- 
 equal, slightly turgid, one smooth, the other with numer- 
 ous median spines, or little horns branched at the ends. 
 
 B, Frustules enveloped in a mass of Gelatin, or contained in 
 Gelatinous Tubes, forming a Frond. 
 
 91. Mastogloia. Frond mammilate ; fr. like Navicula, 
 but hoops with loculi ; aquatic and marine. 
 
 92. Dickieia. Frond leaf-like ; fr. like Navicula or 
 Stamoneis ; marine. 
 
 93. Berkeleya. Frond rounded at base, filamentous at 
 circumference ; fr. navicular ; marine. 
 
 94. Homoeodadia. Frond sparingly divided, filiform ; 
 fr. like Nitzschia ; marine. 
 
 95. Colletonema. Frond filamentous, filaments not 
 branched ; fr. like Navicula or Gyrosigma ; aquatic. 
 
 96. Schizonema. Frond filamentous, branched ; fr. like 
 Navicula; marine. 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 151 
 
 97. Encyonenia. Frond filamentous, but little branched ; 
 fr. like Cymbella ; aquatic. 
 
 98. Syncyclia. Fr. those of Cymbella, united in circular 
 bands, immersed in an amorphous gelatinous frond ; ma- 
 rine. 
 
 99. Frustulia. Fr. as Navicula, irregularly scattered 
 through an amorphous gelatinous mass ; aquatic. 
 
 100. Mir-romega. Fr. as Navicula, arranged in rows in 
 gelatinous tubes, or surrounded by fibres, these being in- 
 closed in a filiform branched frond ; marine. 
 
 The family of Nostochince is allied to the PalmellacecK. 
 It consists of beaded filaments suspended in a gelatinous 
 frond. The gelatinous masses of Nostoc often appear quite 
 suddenly in damp places, and have been called "fallen 
 stars." They attracted the notice of the alchemists, and 
 enter into many of their recipes for the transmutation of 
 metals. What have been termed showers of flesh or of 
 blood, originated in all probability in the rapid develop- 
 ment of similar masses. Many botanists regard them as 
 the " gonidia " of Collema and other lichens. 
 
 The Ostillatoria, so called from the singular oscillatory 
 motion of their filaments, consist also of cells which mul- 
 tiply in a longitudinal direction by self-division. The 
 Ulvacece, to which the grass-green sea-weeds belong, in- 
 crease in breadth as well as length by the subdivision of 
 cells, so as to produce a leaf-like expansion (Plate X, Fig. 
 112). An illustration of the simpler forms of reproduction 
 in Protophytes is seen in Zygnema, so called from the sin- 
 gular manner in which the filaments are yoked together 
 in pairs. In an early stage of growth, while multiplica- 
 tion of cells proceeds by subdivision, the endochrome is 
 generally diffused, but about the time of conjugation it 
 arranges itself usually into a spiral. Adjacent cells put 
 forth protuberances, which unite and form a free passage 
 between them, and the endochrome of one cell passes over 
 
152 THE MICROSCOPIST. 
 
 into the other and forms the spore. In Sphoeroplea the 
 endochrome of the " oospore " breaks up into segments, 
 which escape as " microgonidia." Each of these have 
 two vibratile filaments, which elongate so as to become 
 fusiform, and at the same time change from red to green. 
 Losing their motile power they become filaments, in which 
 the endochrome, by the multiplication of vacuoles, be- 
 comes frothy. After a time the particles of endochrome 
 assume a globular or ovoid shape, and openings occur in 
 the cell- wall. In other filaments the endochrome is con- 
 verted into antherozoids, each of which is furnished with 
 two filaments, by means of which they swim about and 
 enter the openings of- the spore-cells, in which they seem 
 to dissolve away. The contents of the spore-cell then 
 becomes invested with a membranous envelope ; the color 
 changes from green to red ; a second investment is formed 
 within the first, which extends itself into stellate projec- 
 tions. "When set free the mass is a true oospore, and 
 ready to repeat the process above described. In (Edogo- 
 nium the antherozoids are developed in a body called an 
 " androspore," which is set free from a germ-cell, and 
 which being furnished with cilia resembles an ordinary 
 zoospore. This androspore attaches itself to the outer 
 surface of a germ-cell, a sort of lid drops from its free 
 extremity, which sets free its contained antherozoids. 
 These enter an aperture formed in the cell-wall of the 
 oospore, and fertilize the contained mass by blending 
 with it. 
 
 Examination of the Higher Cryptogamia. It would en- 
 large this volume far beyond its proposed limits to refer 
 to the particular instances of form or function which the 
 microscope reveals to the systematic botanist or physiolo- 
 gist, nor is this necessary, since well-written treatises on 
 structural botany are quite available. We content our- 
 selves, therefore, in the remainder of this chapter, with 
 pointing out the methods of examination by w r hich the 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 153 
 
 views of other observers may be verified, or additions 
 made to our knowledge of vegetable life. 
 
 The lower forms of algse and fungi, to which we have 
 already referred, need scarcely any preparation, save the 
 disentanglement of twisted threads under the simple mi- 
 croscope, or a gentle teasing with needles, or rinsing with 
 water. The solution of iodine, and of iodine and sulphuric 
 acid, will suffice to exhibit the nature of the cell-wall and 
 cell-contents. In more highly developed plants it will be 
 necessary to take thin sections from different parts, and 
 in different but definite directions. These sections may 
 be made by hand, or between pieces of pith or cork by 
 means of a section cutter. In some instances some of the 
 methods of staining will also be useful. Dr. Hunt, of 
 Philadelphia, has proposed a plan of staining which is 
 well adapted to all vegetable tissues. He first soaks the 
 part or section in strong alcohol to dissolve the chloro- 
 phyll, then bleaches it in a solution of chlorinated soda. 
 It is then placed in a solution of alum, and afterwards in 
 one of extract of logwood. By transferring it to weak 
 alcohol and afterwards to stronger, it is deprived of its 
 water, and after being made transparent with oil of cloves, 
 it is ready for mounting in balsam or dammar varnish. 
 Care must be taken to wash it well after each of the 
 preliminary steps before staining. 
 
 In the higher algse, the layers of cells assume various 
 sizes and shapes, and the nature of their fructification is 
 of great interest. Sections may be made of the " recep- 
 tacles " at the extremities of the fronds, which contain 
 filaments, whose contents become antherozoids. The pear- 
 shaped sporangia in the receptacles subdivide into clusters 
 of eight cells, called octospores, which are liberated from 
 their envelopes before fertilization. 
 
 The red sea-weeds, or Rhodospenfiece, afford many beau- 
 tiful forms for the microscope. The " tetraspores " are 
 imbedded in the fronds. 
 
154 THE MICROSCOPIST. 
 
 In lichens, the apothecia form projections from the thal- 
 lus, or general expansion produced by cell-division. A 
 vertical section shows them to contain asci or spore-cases 
 amid straight filaments, or elongated cells called para- 
 physes. 
 
 The fronds of Hepaticce or liverworts bear stalks with 
 shield-like disks, which carry antheridia, and others with 
 radiating bodies bearing archegonia, which afterwards 
 give place to the sporangia or spore-cases. The spores 
 are associated with elaters, or elastic spiral fibres, which 
 suddenly extend themselves and disperse the spores. 
 
 The Characece. are often incrusted with carbonate of 
 lime, which may be removed with dilute sulphuric acid. 
 The motion of the bioplasm in the cells of the stem is 
 often well seen. The cells in which the spiral filaments 
 or antheridia are developed, are strung together like a 
 row of pearls. The position and construction of the spores 
 also should be examined, as well as the mode of growth 
 in the plant by division of the terminal cell (Plate XI, 
 Fig. 113). 
 
 Stems of mosses and liverworts should be examined by 
 means of transverse and longitudinal sections. Similar 
 sections through the half-ripe fruit of a moss will show 
 the construction of the fruit, the peristome, the calyptra, 
 etc. The ripe spores may be variously examined dry, in 
 water, in oil of lemons, and in strong sulphuric acid. The 
 capsules or urns of mosses are not now regarded as their 
 fructification, but its product. 
 
 The true antheridia and pistillidia are found among the 
 bases of the leaves, close to the axis. The fertilized " em- 
 bryo-cell " becomes gradually developed by cell-division 
 into a conical body or spore-capsule, elevated on a stalk. 
 The peristome, or toothed fringe, seen around the mouth 
 of the urn when the calyptra or hood, and operculum or 
 lid, are removed, furnishes a beautiful object for the bi- 
 nocular microscope. 
 
PLATE XL 
 
 FIG. 113. 
 
 Antheridia of Chara fragilis: A, antheridium or "globule" developed at the base of pislillidium or 
 "nucule;" B, nucule enlarged, globule laid open by the separation of its valves; c, one of the valves. 
 
 with its group of antheridial lilameuts, each composed of a linear series of cills, within every oii!> of 
 which an antherozoid is formed : in D, E, and F, the successive stages of this formation are seeii ; and at 
 G is shown the escape of the mature antherozoids, 11. (From Carpenter.) 
 
 Development of Prothalium of Pterls terrul<ita:A, spore set free from the theca; B, spore beginning 
 
 to germinate, putting forth the tubular prolongation a, from the principal cell b ; c, fisst formed lineaT 
 series of cells: D, prothallium taking the form of a leaf-like expansion; a first and 6 second radical 
 fibre ; c, d. the two lobes, and e the indentation between them ; /, f, first-formed part of the prothallium ; 
 g, external coat of the original spore ; h, h, antheridia. (From Carpenter.) 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 155 
 
 The Sphagnum, or bog-moss, has large and elongated 
 leaf-cells, with loosely-coiled spiral fibres, and their mem- 
 branous walls have large apertures. Their spores are of 
 two kinds, and when germinating in water, produce a long 
 filament with root-fibres at the lower end and a nodule 
 at the upper, from which the young plant is formed. If 
 grown on wet peat, instead of a filament there is evolved 
 a lobed foliaceous prothattium, resembling the frond of 
 liverworts. 
 
 In ferns the structure approximates to true flowering 
 plants, while the reproductive organs are those of crypto- 
 gamia. Thin sections of the stem, cut obliquely, show 
 the Bcalariform or ladder-like vessels. The fructification 
 is usually found on the under side of the frond in isolated 
 spots called sori. Each of these contains a number of cap- 
 sules or thecce, and each capsule is surrounded by an an- 
 n "I us or ring, whose elasticity opens the capsule w r hen 
 ripe and permits the spores to escape. The spores are 
 somewhat angular, and when vegetating give rise to a 
 leaf-like expansion called a prothallium. In this the an- 
 theridia and archegonia^ which represent the true flower 
 of higher plants, are developed. The ciliated authero- 
 zoids from the antheridia penetrate the cavity of the 
 archegouium and fertilize the " germ-cell," which subdi- 
 vides and becomes a young fern, while the prothallium, 
 having discharged the functions of a nurse, withers away 
 (Plate XI, Fig. 114). The group of Equisetaceaz or horse- 
 tails is interesting from the siliceous skeletons of the epi- 
 dermis, already referred to, page 131, as well as for the 
 elastic filaments attached to their spores. 
 
 EXAMINATION OF HIGHER PLANTS. 
 
 The elementary tissues described in the beginning of 
 this chapter are chiefly characteristic of phanerogamic 
 plants, yet some additional particulars remain to be no- 
 
156 THE MICROSCOPIST. 
 
 ticed in connection with the axis or stem, the leaves, 
 flowers, and fruit. 
 
 1. The Stem. The arrangement of fibro- vascular bun- 
 dles, i. e.. woody fibres and ducts, differs widely in the 
 two botanical divisions of Monocotyledons and Dicotyle- 
 dons. In the first the growth is endogenous, and a section 
 exhibits the bundles of fibres and ducts disposed without 
 regularity in the mass of cellular tissue which forms the 
 basis of the fabric. In the second, or exogenous stems, 
 the fibro- vascular bundles are wedge-shaped, and inter- 
 posed between the bark and the pith, being kept apart by 
 plates of cellular tissue, called medullary rays, proceeding 
 from the pith. 
 
 The course of the vascular bundles in monocotyledons 
 should be carefully followed, either by maceration or 
 minute dissection. In the dicotyledonous stem, sections 
 must be made in three directions, transversely, longitu- 
 dinally across the diameter, and at a tangent from the 
 bundles of fibres. The section-cutter, described page 63, 
 will be serviceable, although a sharp razor or scalpel may 
 serve. The size, form, and contents of the pith-cells 
 should be noticed, and their transition to wood-cells. 
 The arrangement of the medullary rays, of the wood-cells, 
 and of the ducts must also be observed, and in the Coni- 
 ferse the position of the pits. The cambium layer, between 
 the bark and wood, may have its cells rendered more 
 transparent by weak alkalies, and their contents tested 
 with iodine -solution. The course and construction of 
 laticiferous vessels in the bark, when present, and of the 
 cork-cells of the tuberous layer, may be noted. 
 
 Fossil woods may be cut with a watch-spring saw, and 
 ground on a hone like bone or teeth. Sometimes it is 
 best to break off small lamella by careful strokes with a 
 steel hammer. It is sometimes useful to digest fossil 
 wood in a solution of carbonate of soda for several days 
 before cutting. 
 
THE MICROSCOPE IN HISTOLOGY AND BOTANY. 157 
 
 2. Leaves. These should be examined by thin longitu- 
 dinal and transverse sections. The epidermis of both sides 
 should be detached, and the position and arrangement of 
 the stomata observed (Plate VII, Fig. 100). The hairs 
 of the epidermis, the arrangement of the parenchyma, and 
 the distribution of the vascular bundles in the form of 
 nerves, are also of importance. 
 
 3. Flowers. For ascertaining the number and position 
 of the parts of the flower, transverse sections at different 
 heights through an unopened bud may be taken, together 
 with a longitudinal section exactly through the middle. 
 The general structure of sepals and petals corresponds with 
 that of leaves, but there are some peculiarities. Thus the 
 cells of the petal of the geranium exhibit when deprived 
 of epidermis, dried and mounted in balsam, a peculiar 
 mammillated appearance with radiating hairs (Plate VIII, 
 Fig. 102). Anthers and pollen grains are also interesting 
 microscopic objects. The protrusion of the inner mem- 
 brane through the exterior pores in pollen may be stimu- 
 lated by moistening with water, dilute acid, etc. The 
 penetration of the pollen tubes through the tissue of the 
 style may be traced by sections or careful dissection. The 
 heartsease, viola tricolor, and the black and red currant, 
 ribes nigrum and rubrum, have been recommended for this 
 purpose. 
 
 4. Seeds. The reticulations or markings on various 
 kinds of seeds render them frequent objects for observa- 
 tion with the binocular microscope. Adulterations may 
 also be detected in this way, as well as imperfect seeds in 
 any sample, a subject of much importance to the practical 
 farmer. 
 
153 THE MICROSCOPIST. 
 
 CHAPTER XL 
 
 THE MICROSCOPE IN ZOOLOGY. 
 
 WE have already seen that both animal and vegetable 
 structures originate in a jelly-like mass or cell, and that 
 in the simple forms it is difficult, if not impossible, to 
 determine whether the object is an animal or a vegetable. 
 The mode of alimentation, and not structure, is our only 
 guide in the discrimination of the Protozoa or elementary 
 animal forms from Protophytes or simple vegetables. 
 
 It has been proposed by Professor Hseckel to revive the 
 idea of a kingdom of nature intermediate between plants 
 and animals, but it does not appear that any gain to sci- 
 ence would result from such an arrangement. 
 
 I. MONERA. The simplest types of Protozoa are mere 
 particles of living jelly (Plate XII, Fig. 115), yet they 
 possess the power of contraction and extension, and of 
 absorbing alimentary material into their own substance 
 for its nutrition. The Bathybius, from the "globigerina 
 mud," referred to on page 96, seems to have been an in- 
 definite expansion of such protoplasm or bioplasm. 
 
 II. RHIZOPODS. This term (meaning root-footed) is ap- 
 plied to such masses of sarcode or bioplasm as extend long 
 processes, called pseudopodia, as prehensile or locomotive 
 organs (Plate XII, Fig. 116). The Rhizopods are either 
 indefinitely organized jelly, like Monera, or attain a cov- 
 ering or envelope of membrane called ectosarc, while the 
 thin contents are termed endosarc. The first order of 
 Rhizopods, Jteticularia^ consist of indefinite extensions of 
 freely branching and mutually coalescing bioplasm. The 
 second order, Radiolaria, have rod-like radiating exten- 
 sions of the ectosarc, which do not coalesce. The order 
 Lobosa are lobose extensions of the body itself, as in the 
 
THE MICROSCOPE IN ZOOLOGY. 159 
 
 Amoeba princeps already described. Some of this latter 
 order, as Arcella and Difflugia^dre testaceous. In Arcella 
 the test is a horny membrane, analogous to the chitine 
 which hardens the integuments of insects. In Difflugia 
 the test is made up of minute particles of gravel, shell, 
 etc., cemented together. From the opening the amoeboid 
 body puts forth its pseudopodia (Plate XII, Fig. 117). 
 Connected with Rhizopods are three remarkable series of 
 forms, generally marine, and distinguished by skeletons 
 of greater or less density, which aftbrd many objects of 
 interest to the microscopist. These are the Foraminifera, 
 the Pdycystina, and the Sponges or Porifera. The shells 
 of the Foraminifera are calcareous, and those of Polycys- 
 tina siliceous ; both are perforated with numerous aper- 
 tures, which in Polycystiua are often large. TTe have 
 previously referred to these forms as occurring in a fossil 
 state. 
 
 Some Foraminifera have porcellanous, and others vitre- 
 ous or hyaline shells, usually many-chambered, and of every 
 shape between rectilinear and spinal. Most of them are 
 microscopic, but some are of considerable size, as the Or- 
 bitolites, w r hich are found in tertiary limestones in Malabar. 
 The Xummulitic limestone, which extends over large areas 
 of both hemispheres, and of which the pyramids of Egypt 
 are built, is composed of the remains of the genus Num- 
 'mulina; and the Eozoon Canadense has been shown by 
 Drs. Dawson and Carpenter to belong to the Foramini- 
 feral type. 
 
 In some Foraminifera the true shell is replaced by a 
 sandy envelope, whose particles are often cemented by 
 phosphate of iron. Dr. Carpenter, whose researches have 
 largely extended our knowledge of this group, pertinently 
 remarks that " there is nothing more wonderful in nature 
 
 O 
 
 than the building up of these elaborate and symmetrical 
 structures by mere jelly specks, presenting no trace what- 
 ever of that definite ' organization ' which we are accus- 
 
160 THE MICKOSCOPIST. 
 
 tomed to regard as necessary to the manifestations of 
 conscious life."* 
 
 The Polycystina, like the Foraminifera, are beautiful 
 objects for/ the binocular microscope, with the black- 
 ground illumination by the Webster condenser, the spot- 
 lens, or the paraboloid. 
 
 The Porifera or sponges begin life as solitary Amoeba, 
 and amid aggregations formed by their multiplication, 
 the characteristic spicules of sponge-structure make their 
 appearance. In one group, the skeleton is a siliceous 
 framework of great beauty. In Hyalonema, the silica is 
 in bundles of long threads like spun glass. Sometimes 
 sponge spicules are needle-like, straight or curved, pointed 
 at one or both ends ; sometimes with a head like a pin, 
 furnished with hooks, or variously stellate. Dr. Carpen- 
 ter thinks it probable that each spicule was originally a 
 segment of sarcode, which has undergone either calcifica- 
 tion or silicification (Plate XII, Fig. 118). 
 
 III. INFUSORIAL ANIMALCULES. From the earliest his- 
 tory of the microscope, the minute animals found in vari- 
 ous infusions or in stagnant pools, etc., have attracted 
 attention. We owe to Professor Ehrenberg the first sci- 
 entific arrangement of this class, and although more ex- 
 tended observations have changed his classification, yet 
 many of his views are still accepted by the most recent 
 investigators. Ehrenberg divided this class into two 
 groups, which represent very different grades of organi- 
 zation. The first he called Polygastrica (many-stomached) 
 from a view of their structure, which subsequent examin- 
 ations have not confirmed. The other group is that of 
 Rotifera or Rotatoria, a form of animal life which is most 
 appropriately classed among worms. The term Infusoria 
 is now applied to those forms which Professor Ehrenberg 
 
 * The Microscope and its Revelations, by W. B. Carpenter, M.D., 
 LL.D., etc. 
 
PLATE XII. 
 
 FIG. 115. 
 
 Monera (Amoeba). 
 
 A, Difflugiaproteiformis; B,Difflvgia ohlonga; c, Arcella 
 acuminala; D, Arcella dentata. 
 
 Gromia oviformis, with its pseudopodia extended. 
 
 Fio. 118. 
 
 Structure of Grant ia compressa: B, small portion highly magnified. 
 
THE MICROSCOPE IN ZOOLOGY. 161 
 
 called polygastric animalcules. Yet a large section de- 
 scribed by him in this connection, including the Desmidi- 
 acece, Diatomacece, Volvotinece, and other protophytes, have 
 been transferred by naturalists to the vegetable kingdom. 
 
 The bodies of the Infusoria consist of sarcode or bio- 
 plasm, having an outer layer of firmer consistence. Some- 
 times the integument is hardened on one side so as to form 
 a shield, and in other cases it is so prolonged and doubled 
 upon itself as to form a sheath or cell, within which the 
 animalcule lies. The form of the body is more definite 
 than that of Amoeba, so as to be characteristic of species. 
 It may be oblong, oval, or round ; and some kinds, as 
 Vorticella, are attached to a footstalk, which has the power 
 of contracting in a spiral coil. !N"o distinct muscular 
 structure can be detected in the Infusoria, yet the general 
 substance of the body is contractile. In most species 
 short hair-like filaments or cilia project from the surface, 
 sometimes arranged in one or more rows round the mouth, 
 and moving to all appearance under the influence of voli- 
 tion. In others there are one or two flagelliform filaments, 
 or long anterior cilia with vibratile ends. Others, again, 
 have setae or bristles, which assist in locomotion. The 
 motions of some are slow, and of others quite rapid. 
 
 The interior of the sarcode body exhibit certain round- 
 ish spots, sometimes containing Diatoms or other foreign 
 substances. They have been called gastric vesicles, cells, 
 spaces, or sacculi. They are only visible from their con- 
 tents, and seem to be mere spaces without a living mem- 
 brane. If a little indigo or carmine is diffused in the 
 water which contains the Infusoria, the cavities will soon 
 be filled and become distinct. If watched carefully they 
 will appear to move round the body of the animal, and as 
 the pigment escapes at some part of the surface, the spots 
 will disappear. Ehrenberg regarded these spots as so 
 many stomachs arranged about a common duct, but the 
 common opinion at present regards them as temporary 
 
 11 
 
162 THE MICROSCOPIST. 
 
 digestive sacs made by the inclosure of food by the soft 
 bioplasm. 
 
 In addition to the "vacuoles" described, contractile 
 vesicles are seen which contract and dilate rhythmically, 
 and do not change their position. They have been con- 
 sidered to serve for respiration. 
 
 Most of the Infusoria multiply by self-division (Plate 
 XIII, Fig. 119), and at certain times undergo an encyst- 
 ing process, much resembling the "still" condition of Pro- 
 tophytes, and like that serving for preservation under 
 circumstances which are unfavorable to ordinary vital 
 activity. The gemmules or progeny which result from 
 the bursting of the cyst do not always resemble the parent 
 in form. The recent researches of Drs. Dallinger and 
 Drysdale have shown considerable variety in the life his- 
 tory of the Infusoria. In some instances the product of 
 the encysting process was not a mass of granules, but an 
 aggregation of minute germinal particles not more than 
 sWofjoth f an i nc h i n diameter, and capable of resisting 
 heat, either by boiling or by dry heating up to 300 F. 
 
 The observations of M. Balbiani show that in many of 
 the Infusoria, male and female organs are combined in 
 the same individual, but that a congress of two is neces- 
 sary for the impregnation of the ova, those of each being 
 fertilized by the spermatozoa of the other. 
 
 There is also a curious tribe of suctorial animalcules 
 called Acinetce, which put forth tubular prolongations 
 which penetrate the bodies of other species and grow in 
 their interior as parasites. 
 
 The systematic arrangement of the Infusoria is yet 
 unsettled. Ehrenberg's families, excluding those now 
 placed among Algre or Ehizopods, are as follows : 
 
THE MICROSCOPE IN ZOOLOGY. 163 
 
 A. Intestinal tube absent. 
 
 , Body variable, without cilia. 
 
 Carapace absent, ASTASI.EA. 
 
 Carapace present, DINOBRYINA. 
 
 Cilia or setae present. 
 
 Carapace absent, ..... CYCLIDINA. 
 
 Carapace present, ..... PERIDIN^EA. 
 
 B. Intestinal tube present. 
 
 Orifice single. 
 
 Carapace absent, ..... VORTICELLINA. 
 Carapace present, . . . . OPHRYDINA. 
 
 Two opposite orifices. 
 
 Carapace absent, ENCHELIA. 
 
 Carapace present, ..... COLEPINA. 
 Orifices differently placed. 
 Carapace none. 
 
 No tail, but a proboscis, . . TRACHELINA. 
 Tail present, mouth anterior, . OPHRYOCERCJNA. 
 
 Carapace present, ASPIDISCINA. 
 
 Orifices ventral. 
 
 Carapace absent. 
 
 Motion by cilia, .... COLPODEA. 
 Motion by organs, . . . . OXYTRICHINA. 
 Carapace present, ..... EUPLOTA. 
 
 IV. ROTATOEIA OR WHEEL ANIMALCULES. These are 
 microscopic, aquatic, transparent animals, of a higher 
 organization than the Infusoria, and belonging in all 
 probability to the class Yervn.es. Their chief interest to 
 the microscopist is derived from the possession of a more 
 or less lobed, retractile disk, covered with cilia, which, 
 when in motion, resemble revolving wheels. They have 
 also a complicated dental apparatus, and generally a dis- 
 tinct alimentary canal, and are reproduced by ova. Some 
 are more or lees covered by a carapace, and in most there 
 is a retractile tail-like foot, sometimes terminated by a 
 suctorial disk or a pair of claw-like processes. The ner- 
 vous and vascular systems are not well known, although 
 traces of them are seen. The young of some possess an 
 eye which often disappears in the adult. They are re- 
 
164 THE MICROSCOPIST. 
 
 markably tenacious of life, having in some instances re- 
 vived after having been kept dry for several years. 
 
 M. Dujardin divides the Rotifera into four groups or 
 natural families : 
 
 1. Those attached by the foot, which is prolonged into 
 a pedicle. It includes two families, the Floscularians and 
 the Melieertians, in the first of which the sheath or cara- 
 pace is transparent, and in the other composed of little 
 rounded pellets (Plate XIII, Fig. 120). 
 
 2. The common Rotifer and its allies, which swim freely 
 or attach themselves by the foot at will (Plate XIII, Fig. 
 121). 
 
 3. Those which are seldom or never attached, the Bra- 
 chionians and the Furcularians. The former are short, 
 broad, and flat, and inclosed in a sort of cuirass ; the latter 
 are named from a bifurcated, forcep-like foot (Plate XIV, 
 Fig. 122). 
 
 4. The Tardigrada or water bears. These have no 
 ciliated lobes, but are in other respects like their allies, 
 and seem to be a connecting link between the Rotifers 
 and worms. The segments of the body, except the head, 
 bear two fleshy protuberances furnished with four curved 
 hooks.* 
 
 V. POLYPS. The animals of this class were formerly 
 called Zoophytes, or animal flowers. They are the most 
 important of coral-making animals, although the Hydroids 
 and Bryozoa, together with some Algae, as the Nulli pores, 
 share with them the formation of coral, which is a secre- 
 tion of calcareous matter. Dana's work on corals gives a 
 classification, of which we present a summary. 
 
 A good idea of a polyp may be had from comparison 
 with the garden aster, the most common form of a polyp 
 flower being a disk fringed with petal-like organs called 
 tentacles. 
 
 The internal structure, like the external, is radiate, and 
 
 * Carpenter on the Microscope. 
 
PLATE XIII. 
 
 FIG. 119. 
 
 Fissiparous multiplication of ChUodon eucullulus. 
 
 FIG. 120. 
 
 FIG. 121. 
 B A 
 
 Eodifer vulgarit, as seen at A, with 
 the wheels drawn in, and at B with 
 the wheels expanded; a, mouth; ft, 
 eye-spots; c, wheels; d, calcar (an- 
 tenna?); e, jaws and teeth; /, ali- 
 mentary canal ; g, glandular (?) mass 
 enclosing it; A, longitudinal mus- 
 cles ; , i, tubes of water vascular 
 system ; k, young animal ; I, cloaca. 
 
 Stephanoceros Eichornii 
 
THE MICROSCOPE IN ZOOLOGY. 165 
 
 the cavity of the body is divided by septa into narrow 
 compartments. The walls contain circular and longitu- 
 dinal muscles, which serve for contraction of the body, 
 which is afterwards expanded by an injection or absorp- 
 tion of water by the mouth. 
 
 The most interesting part of the structure of these 
 animals, to the microscopist, is the multitude of lasso-cells, 
 called also nettling -cells, thread capsules, and cnidce, which 
 stud the tentacles and other parts of the body, and by 
 means of which the prey of the polyp is at once pierced 
 and poisoned. A small piece of the tentacle of a sea 
 anemone placed in a compressorium under the microscope, 
 and subjected to gentle pressure, will show the protrusion 
 of many little dart-like processes attached to thread-like 
 filaments. Many observations indicate the injection of a 
 poison through these darts, which is instantly fatal to 
 small animals (Plate XIV, Fig. 123). 
 
 The polyp has no circulating fluid but the results of 
 digestion mixed with salt water, no bloodvessels but the 
 vacuities among the tissues, and no passage for excrements 
 except the mouth and the pores of the body. Eeproduc- 
 tion is both by ova and by buds. 
 
 I. Actinoid polyps are related to the Actinea or sea 
 anemone. The number of tentacles and interior septa 
 is a multiple of six. 
 
 II. Cyathophylloid polyps have the number of tentacles 
 and septa a multiple of four. 
 
 III. Alcyonoid polyps have eight fringed tentacles. The 
 Alcyonium tribe are among the most beautiful of coral 
 shrubs. The Gorgonia tribe has reticulated species like 
 the sea fan, and bears minute calcareous spicules, often 
 brilliantly colored. The Pennatula tribe is unattached, 
 and often rod-like, with the polyps variously arranged. 
 
 VI. HYDROIDS. The type of this class is the common 
 Hydra, which is often found attached to leaves or stems 
 of aquatic plants, etc. It is seldom over half an inch long. 
 
166 THE MICROSCOPIST. 
 
 It has the form of a polyp, with long slender tentacles. 
 Besides these tentacles with their lasso-cells, it has no 
 special organs except a mouth and tubular stomach. Like 
 the fabled Hydra, if its head be cut off another will grow 
 out, and each fragment will in a short time become a per- 
 fect animal, supplying whatever is wanting, hence its name 
 (Plate XIV, Fig. 124). The Hydra has the power of lo- 
 comotion, bending over and attaching its head until the 
 tail is brought forward, somewhat after the manner of a 
 leech. 
 
 Compound Hydroids may be likened to a Hydra whose 
 buds remain attached and develop other buds until an 
 arborescent' structure, called a polypary, is produced. The 
 stem and branches consist of fleshy tubes with two layers, 
 the inner one having nutritive functions, and the outer 
 secreting a hard, calcareous, or horny layer. The indi- 
 viduals of the colony are of two kinds, the polypite or 
 nutritive zooid, resembling the Hydra, and the gonozooid, 
 or sexual zooid, developed at certain seasons in buds of 
 particular shape. 
 
 To mount compound Hydrozoa, or similar structures, 
 place the specimen alive in a cell, and add alcohol drop 
 by drop to the sea-water ; this will cause the animals to 
 protrude and render their tentacles rigid. Then replace 
 the alcohol with Goadby's solution, dilute glycerin, or 
 other preserving fluid. 
 
 VII. ACALEPIIS, or sea-nettles, are of all sizes, from an 
 almost invisible speck to a yard in diameter. They swarm 
 in almost every sea, and are frequently cast upon the 
 beach by the waves. They are transparent, floating free, 
 discoid or spheroid, often shaped like a mushroom or um- 
 brella, and their organs are arranged radiately round an 
 axis occupied by the pedicle or stalk. They are furnished 
 with muscular, digestive, vascular, and nervous systems. 
 They were formerly divided into 
 
 1. Palmonigrada, from their movements being effected 
 
-PLATE XIV. 
 
 FIG. 122. 
 
 Noteus quadricornis : A, dorsal view ; B, side view. 
 
 FIG. 123. 
 
 Fie. 124. 
 
 
 Hydra j'usca in gemination. 
 
 Filiferous capsules of Helianthoid Polypes : A,B, 
 Corynactis Allmanni ; c, E, F, Carijophyl'lia Smilhii ; 
 D, G, Actinia crass icornis ; H, Actinia Candida. 
 
THE MICROSCOPE IN ZOOLOGY. 167 
 
 by a rhythmical contraction and dilation, as in Rhizistama, 
 etc. 2. Cilograda, moving by narrow bands of vibratile 
 cilia variously disposed over the body. In Beroe the cilia 
 are transformed into flat fin-like shutters, arranged in 
 eight longitudinal bands. In Yenus's girdle, Cesium Ve- 
 neris, the margins of a gelatinous ribbon are fringed with 
 cilia. 3. Physograda, which move by means of an expan- 
 sile bladder, as the Physalia, or Portuguese man of war. 
 4. Cirrigrada, possessing a sort of cartilaginous skeleton, 
 and furnished with appendages called cirri, serving as oars 
 and for prehension, as Porpita and Velella. In the latter 
 there is also a subcartilaginous plate rising at right angles 
 from the surface supporting a delicate membrane, which 
 acts as a sail. 
 
 This classification has been laid aside since the micro- 
 scopic discovery of the close relationship between the 
 Hydrozoa and the Medusoid Acalephs, and the latter are 
 now subdivided into the " naked-eyed " and the " covered- 
 eyed " Acalephs. The alternation of generations, page 
 126, is fully illustrated in this class. The embryo emerges 
 as a ciliated gemmule, resembling one of the Infusoria. 
 One end contracts and attaches itself so as to form a foot, 
 while the other enlarges and becomes a mouth, from which 
 four tubercles sprout and become tentacles. Thus a Hy- 
 dra-like polyp is formed, which acquires additional tenta- 
 cles. From such a polyp many colonies may rise by gem- 
 mation or budding, but after a time the polyp becomes 
 elongated, and constricted below the mouth. The con- 
 stricted part gives origin to other tentacles, while similar 
 constrictions are repeated round the lower parts of the 
 body, so as to divide it into a series of saucer-like disks, 
 which are successively detached and become Medusae 
 (Plate XY, Figs. 125, 126). 
 
 YIIL ECHIXODERMS. This class includes the star-fishes, 
 the sea-urchins or sea-eggs, the sea-slugs, and the crinoids 
 or stone lilies of former ages. If we imagine a polyp with 
 
168 THE MICROSCOPIST. 
 
 a long stem to secrete calcareous matter, not merely exter- 
 nally, but in the substance of its body and tentacles, such 
 polyp when dried would present some such appearance as 
 the fossil Encrinoid Echinoderms of past times. The im- 
 agination of such a polyp without a stem, and having 
 sucker-like disks on its arms, will give us the picture of 
 a star-fish (Asterias). Imagine the rays diminished and 
 the central part extended, either flat or globular, and we 
 have the form of Echini with the spines removed. The 
 JSblothurice have elongated membranous bodies, with im- 
 bedded spiculse. 
 
 The structure of Echinoderms is quite complex, and 
 belongs to comparative anatomy rather than microscopy, 
 yet some directions for the study of these forms is essen- 
 tial to our plan. 
 
 Thin sections of the shells, spines, etc., may be made by 
 first cutting with a fine saw, and rubbing down with a 
 flat file. They should be smoothed by rubbing on a hone 
 with water, cemented to a glass slip with balsam, and 
 carefully ground down to the required thickness. They 
 may be mounted in fluid balsam. 
 
 Many Echinoderms have a sort of internal skeleton 
 formed of detached plates or spiculse. The membranous 
 integument of the Holothurise have imbedded calcareous 
 plates with a reticulated structure, and they are often 
 furnished with appendages, as prickles, spines, hooks, etc., 
 which form beautiful microscopic objects. 
 
 The larva of an Echinoderm is a peculiar zooid, which 
 develops by a sort of internal gemmation. One of the 
 most remarkable of these larvae has been called Bipin- 
 naria. 
 
 IX. BRYOZOA OR POLYZOA. Microscopic research has 
 removed this class from the polyps, which they resemble, 
 to the molluscan sub-kingdom. They have a group of 
 ciliated tentacles round the mouth, but have a digestive 
 system far more complex than polyps. They form delicate 
 
PLATE XV. 
 
 FIG. 125. 
 
 FIG. 127. 
 
 Development of Medusa buds in Syn- 
 choryna Sarsii. 
 
 FIG 126. 
 
 
 a 
 
 
 
 
 
 ! 
 
 
 t 
 
 -;- 
 
 
 
 . ., , . 
 L . . 
 
 
 f 
 
 
 
 
 - 
 
 w ^ 
 
 
 
 
 LSI 
 
 .:. .-.-'- .- 
 
 
 A, Portion of Cellularia ciliata, enlarged ; B, 
 one of the " bird's-head " of Bugula aiicularia, 
 more highly magnified, and seen in the act of 
 grasping another. 
 
 FIG. 128. 
 
 Successive stages of development of Medusa 
 buds from Strtibila. larva. 
 
 Sertularia cupressi>ia:A, natural size; 
 B, portion magnified. 
 

 THE MICROSCOPE IN ZOOLOGY. 169 
 
 corals, either membranous or calcareous, made up of minute 
 cabin-like cells, which are either thin crusts on sea-weeds, 
 rocks, etc., or slender moss-like tufts, or groups of thin 
 curving plates, or net-like fronds, and sometimes thread- 
 like lines or open reticulations. The cells of a group have 
 no connection with a common tube, as the Hydroids, but 
 the alimentary system of each little Bryozoon is indepen- 
 dent. 
 
 Many of the Polyzoa have curious appendages to their 
 cells, of two kinds ; the first are called birds'-head pro- 
 cesses or avicularia. They consist of a body, a hinge or 
 lower jaw-like process, and a stalk. The lower portion is 
 moved by an elevator and depressor muscle, and during 
 life the motion is constant. The second kind, or vibracula, 
 is a hollow process from which vibratile filaments project 
 (Plate XV, Figs. 127,128). 
 
 X. TUNIC AT A. These molluscs are so named from the 
 leathery or cartilaginous tunic which envelops them, and 
 which often contains calcareous spicula. Like the Bryo- 
 zoa they tend to produce composite structures by gemma- 
 tion, but they have no ciliated tentacles. They are of 
 most interest to the microscopist from the peculiar actions 
 of their respiratory and circulatory organs, which may be 
 seen through the transparent walls of small specimens. 
 The branchial or respiratory sac has a beautiful network 
 of bloodvessels, and is studded with vibratile cilia for dif- 
 fusing water over the membrane. The circulation is re- 
 markable from the alternation of its direction. 
 
 The smaller Tunicata are usually found aggregate, in- 
 vesting rocks, stones and shells, or sea-weeds ; a few are 
 free. 
 
 Synopsis of the Families. 
 
 A. Attached ; mantle and test united only at the ori- 
 fices. 
 
 1. Botryllidce. Bodies united into systems. 
 
170 THE MICROSCOPIST. 
 
 2. Clavelinidce. Bodies distinct, but connected by a 
 common root thread. 
 
 3. AscidiadcB. Bodies unconnected. 
 
 B. Free ; mantle and test united throughout. 
 
 4. Pelonceadce. Orifices near together. 
 
 5. Salpadce. Orifices at opposite ends. 
 
 XI. CONCHIFERA. This class consists of bivalve mol- 
 luscs, and is chiefly interesting to the microscopist from 
 the ciliary motion on their gills and the structure of the 
 shell. 
 
 The ciliary motion may be observed in the oyster or 
 mussel, by detaching a small piece of one of the bands 
 which run parallel with the edge of the open shell, placing 
 it on a glass slide in a drop of the liquid from the shell, 
 separating the bars with needles, and covering it with 
 thin glass : or the fragment may be placed in the live box 
 and submitted to pressure. The peculiar movement of 
 each cilium requires a high magnifying power. It appears 
 to serve the double purpose of aeration of the blood and 
 the production of a current for the supply of aliment. 
 
 Dr. Carpenter has shown that the shells of molluscs 
 possess definite structure. In the Margaritacece the exter- 
 nal layer is prismatic, and the internal nacreous. The 
 nacreous or iridescent lustre depends on a series of grooved 
 lines produced by laminae more or less oblique to the plane 
 of the surface. The shells of Terebratulce are marked by 
 perforations, which pass from one surface to another. 
 The rudimentary shell of the cuttle-fish (of the class 
 Cephalopoda], or " cuttle-fish bone," is a beautiful object 
 either opaque or in the polariscope. Sections may be 
 made in various directions with a sharp knife, and 
 mounted as opaque objects or in balsam. 
 
 XII. G-ASTEROPODA. These molluscs are either naked, 
 as the slug, or have univalve shells, as the snail, the lim- 
 pet, or the whelk. As in the other classes referred to, 
 the details of anatomical structure are full of interest ; 
 
PLATE XVI. 
 
 FIG. 130. 
 
 FIG. 129. 
 
 A, female of Cyclops quadricornis; a, body ; 6, tail ; 
 c, antenna; d, antennule; e, feet; /, plumose setae of 
 tail ; B, tail, with external egg-sacs ; c, D, E, F, G, 
 successive stages of development of young. 
 
 FIG. 131. 
 
 Metamorphosis of Carcinus mamas: A, first stage ; B, second stage ; c, third stage, 
 in which it begins to assume the adult form ; D, perfect form. 
 
THE MICROSCOPE IN ZOOLOGY. 171 
 
 but to the microscopist the palate, or tongue as it is called 
 a tube which passes beneath the mouth, opening ob- 
 liquely in front, and which is covered with transverse 
 rows of minute teeth set upon plates presents characters 
 of great value in classification. These palates require 
 careful dissection, and when mounted in balsam become 
 beautiful polariscope objects (Plate XYI, Fig. 129). 
 
 XIII. CEPHALOPODA. The crystalline lens in the eye of 
 the cuttle-fish is said to be of the same form as the well- 
 known " Coddington lens." The skin of this class con- 
 tains a curious provision for changing its hue, consisting 
 of large pigment-cells containing coloring matter of vari- 
 ous tints. 
 
 The suckers, or prehensile disks, on the arms of cephal- 
 opods often make interesting opaque objects when dried. 
 
 XIV. ENTOZOA. These are parasitic animals belonging 
 to the class of worms. They are characterized by the 
 absence or low development of the nutritive system, and 
 the extraordinary development of their reproductive or- 
 gans. Thus the Tcenia or tapeworm has neither mouth 
 nor stomach, the so-called " head" being merely an organ 
 for attachment, while each segment of the "body" con- 
 tains repetitions of a complex generative apparatus. 
 
 Among the Xematoid or round worms, the Anguillulce, 
 or little eel-like worms, found in sour paste, vinegar, etc., 
 as well as the Trichina spiralis, inhabiting the voluntary 
 muscles, are generally classified. 
 
 ORDER I. STERELMIXTHA. Alimentary canal absent or 
 indistinct. 
 
 FAMILY 1. Cestoidea. Tapeworms; body strap-shaped, 
 divided into transverse joints ; alimentary canal indistinct. 
 The cystic Entozoa (Echinococcus, etc.) are nurse or larval 
 forms of Cestoidea. 
 
 FAMILY 2. Trematoda. Body mostly flattened ; alimen- 
 tary canal distinct ; branched. 
 
172 THE MICROSCOPIST. 
 
 FAMILY 3. Acanthocephala. Body flattened, transversely 
 wrinkled ; sexual organs in separate individuals. 
 
 FAMILY 4. Gordiaeea (Hairworms). Body filamentous, 
 cylindrical ; alimentary canal present ; sexes distinct. 
 
 FAMILY 5. Protozoidea or Gregarinida. Probably larval 
 forms. 
 
 ORDER II. CJELELMINTHA. Alimentary canal distinct. 
 
 FAMILY 1. Nematoidea (Round worms). Body cylindri- 
 cal, hollow ; sexes separate. 
 
 The Enoplidce tribe is distinguished by an armature of 
 hooks or styles round the mouth. Most of them are 
 microscopic. 
 
 XY. ANNUL AT A (Red-blooded. Worms). Some of these, 
 as the Serpula, etc., are inclosed in tubes formed of a shelly 
 secretion, or built up of grains of sand, etc., agglutinated 
 together. Many have special respiratory appendages to 
 their heads, in which the microscope will exhibit the cir- 
 culation. The worms of the Nais tribe, also, are so trans- 
 parent as to be peculiarly fitted for microscopic study of 
 structure. The dental apparatus of the leech consists of 
 a triangular aperture in a sucking disk, furnished with 
 three semicircular horny plates, each bordered with a row 
 of eighty to ninety teeth, which act like a saw. 
 
 ORDER 1. TURBELLARIA. Body bilateral, soft, covered 
 with vibratile cilia, not segmented ; eyes distinct ; sexless 
 or hermaphrodite. 
 
 ORDER 2. SUCTORIA (Apoda). Body elongate, ringed, 
 without bristles or foot-like tubercles ; locomotion by 
 sucking-disks ; no external branchiae. 
 
 ORDER 3. SETIGRADA (Chcetopoda). Body ringed, elon- 
 gate, with feet or setigerous rudiments of them ; external 
 branchiae usually present. 
 
 XVI. CRUSTACEA. In the family of Isopoda the micros- 
 copist will find the Ascellus vulgaris, or water wood-louse, 
 of great interest, as readily exhibiting the dorsal vessel 
 and circulating fluids. 
 
THE MICROSCOPE IN ZOOLOGY. 173 
 
 The family of Entomostraca contains a number of gen- 
 era, nearly all of which are but just visible to the naked 
 eye. They are distinguished by the inclosure of the body 
 in a horny or shelly case, often resembling a bivalve shell, 
 though sometimes of a single piece. The tribe of Lophy- 
 ropoda (bristly -footed), or " water-fleas," is divided into 
 two orders, the first of which, Ostracoda, is characterized 
 by a bivalve shell, a small number of legs, and the absence 
 of an external ovary. A familiar member of this order, 
 the little Cypris, is common in pools and streams, and may 
 be recognized by its two pairs of antennse, the first of 
 which is jointed and tufted, while the second is directed 
 downwards like legs. It has two pairs of legs, the poste- 
 rior of which do not appear outside the shell. 
 
 The order Copepoda has a jointed shell, like a buckler, 
 almost inclosing the head and thorax. To this belongs 
 the genus Cyclops (named from its single eye), the female 
 of which carries on either side of the abdomen an egg 
 capsule, or external ovarium, in which the ova undergo 
 their earlier stages of development (Plate XVI, Fig. 130). 
 
 The Daphnia pulex, or arborescent water-flea, belongs to 
 the order Cladocera and tribe Branchiopoda. The other 
 order of this tribe, the Phyllopoda, has the body divided 
 into segments, furnished with leaf-like members or " fin 
 feet." 
 
 When first hatched, the larval Entomostraca differ 
 greatly from the adult. The larval forms of higher 
 Crustacea resemble adult Entomostraca. 
 
 The suctorial Crustacea, order Siphonostoma, are gener- 
 ally parasitic, mostly affixed to the gills of fishes by means 
 of hooks, arms, or suckers, arising from or consisting of 
 modified foot-jaws. The transformations in this order, as 
 in the Lerncea, seem to be a process of degradation. The 
 young comes from the egg as active as the young of 
 Cyclops, which they resemble, and pass through a series 
 of metamorphoses in which they cast off their locomotive 
 
174 THE MICROSCOPIST. 
 
 members and their eyes. The males and females do not 
 resemble each other. 
 
 The order Cirrhipeda consists of the barnacles and their 
 allies. In their early state they resemble the Entomos- 
 traca, are unattached, and have eyes. After a series of 
 metamorphoses they become covered with a bivalve shell, 
 which is thrown off; the animal then attaches itself by 
 its head, which in the barnacle becomes an elongated 
 pedicle, and in Balanus expands into a disk. The first 
 thoracic segment produces the "multivalve" shell, while 
 the other segments evolve the six pairs of cirrhi, which 
 are slender, tendril-like appendages, fringed with ciliated 
 filaments. 
 
 In the order Amphipoda, the Gammarus pulex, or fresh- 
 water shrimp, and the Talitrus saltator, or sandhopper, 
 may be interesting to the microscopist. 
 
 The order Decapoda, to which belong the crab, lobster, 
 shrimp, etc., is of interest, from the structure of the shell 
 and the phenomena of metamorphosis. The shell usually 
 consists of a horny structureless layer exteriorly, an areo- 
 lated stratum, and a laminated tubular substance. The 
 difference between the adult and larval forms in this order 
 is so great that the young crab was formerly considered 
 a distinct genus, Zoea (Plate XYI, Fig. 131). 
 
 For the preservation of specimens of Crustacea, Dr. 
 Carpenter recommends glycerin jelly as the best medium. 
 
 XVII. INSECTS. Many insects may be mounted dry, 
 as opaque objects. They may be arranged in position by 
 the use of hot water or steam. Those which are trans- 
 parent enough may be mounted in balsam, and very deli- 
 cate ones in fluid. To display the external chitinous cov- 
 ering of an entire insect, it may be soaked in strong liquor 
 potassse, and the internal parts squeezed out in a saucer 
 of w^ater by gently rolling over it a camel's-hair brush. 
 It may be put on a slide, and the cover fastened by tying 
 with a thread. It should then be soaked in turpentine 
 
^ 
 THE MICROSCOPE IN ZOOLOGY. 175 
 
 until quite transparent, when it may be removed, the tur- 
 pentine partially drained off, and a solution of balsam in 
 chloroform allowed to insinuate itself by capillary attrac- 
 tion. Gentle heat from a spirit-lamp will be useful at this 
 stage of the mounting. 
 
 Small insects hardly need soaking in caustic potash, as 
 turpentine or oil of cloves will render them after awhile 
 quite transparent, and their internal organs are beautifully 
 seen in the binocular microscope. Thin sections of insects 
 are instructive, and may be made with a section-cutter by 
 first saturating the body with thick gum mucilage, and 
 then incasing in melted paraffin. 
 
 Many insects and insect preparations are well preserved 
 in glycerin. 
 
 The eggs of insects are often interesting objects, and 
 should be mounted in fluid. 
 
 Wing cases of beetles are often very brilliant opaque 
 objects. Some are covered with iridescent scales, and 
 others have branching hairs. Many are improved by 
 balsam, and this may be determined by touching with 
 turpentine before mounting. 
 
 Scales of Lepidoptera, etc., may be exhibited in their 
 natural arrangement by mounting a small piece of wing 
 dry. If desired as test objects, a slide or thin cover, after 
 having been breathed on, may be slightly pressed on the 
 wing or body of the insect. The scales are really flattened 
 cells, analogous to the epidermic cells of higher animals. 
 Some have their walls strengthened by longitudinal ribs, 
 while others, as the Podurce, show a beaded appearance 
 under high powers from corrugation. Dr. Carpenter be- 
 lieves the exclamation marks in the scales of the latter to 
 be the most valuable test of the excellence of an objective. 
 
 Hairs of insects are often branched or tufted. The hair 
 of the bee shows prismatic colors if the chromatic aberra- 
 tion of the object-glass is not exactly neutralized. 
 
 Antennae vary greatly in form, and are often useful in 
 
176 THE MICROSCOPIST. 
 
 classification (Plate XVII, Fig. 132). Thus in the Cole- 
 optera we have the Serricornes, or serrated antennae; the 
 Clavicornes^or clubbed ; the Palpicornes, with antennae no 
 larger than palpi ; the Lamellicornes, with leaf-like appen- 
 dages to the antennae; and the Longicornes, with antennae 
 as long or longer than the body. Nerve : fibres, ending in 
 minute cavities in the antennae, have been traced, which 
 are supposed to be organs of hearing. The antennae should 
 be bleached to exhibit them. The bleaching process is 
 also useful for other parts of insects. The bleaching fluid 
 consists of a drachm of chlorate of potass in about two 
 drachms of water, to which is added about a drachm of 
 hydrochloric acid. 
 
 Compound eyes of insects are always interesting. They 
 are quite conspicuous, and often contain thousands of 
 facets, or minute eyes, called ocelli (Plate XVII, A B, Fig. 
 133). Besides these, insects possess rudimentary single 
 eyes, like those of tke Arachnidce. These are at the top 
 of the head, and are termed stemmata (Plate XVII, a, 
 Fig. 133). To display the " corneules," or exterior layer 
 of the compound eye, the pigment must be carefully 
 brushed away after maceration. A number of notches 
 may then be made around the edge, the membrane flat- 
 tened on a slide, and mounted in balsam. Vertical sec- 
 tions may be made while fresh, so as to trace the relations 
 of the optic nerve, etc. The dissecting microscope and 
 needles will be found useful (Plate XVII, Fig. 132). 
 
 Mouths of insects present great varieties. In the beetles 
 the mouth consists of a pair of mandibles, opening later- 
 ally ; a second pair, called maxillae ; a labrum or upper 
 lip; an under lip or labium; one or two pairs of jointed 
 appendages to the maxillae, termed maxillary palpi ; and 
 a pair of labial palpi. The labium is often composed of 
 distinct parts, the first of which is called the mentum or 
 chin, and the anterior part the ligula or tongue. This 
 latter part is greatly developed in the fly, and presents 
 
PLATE XVII. 
 
 FIG. 132. 
 
 Various Antennae of Insects. 
 FIG. 134. 
 
 Tongue of common Fly. 
 
 Foot of Fly. 
 
 FIG. 136. 
 
 
 Tracheal system of Nepa (Water-scorpion). 
 
THE MICROSCOPE IN ZOOLOGY. 177 
 
 a curious modification of tracheal structure, which is 
 thought to serve the function of suction (Plate XVII, 
 Fig. 134). The tongue of the bee is also an interesting 
 object. In the Diptera the labrum, maxillse, mandibles, 
 etc., are converted into delicate lancets, termed setse, and 
 are used to puncture the epidermis of animals or plants, 
 from which the juices may be drawn by the proboscis. 
 In the Lepidoptera the labrum and mandibles are reduced 
 to minute plates, while the maxillae are greatly elongated, 
 and are united to form the haustellum, or true proboscis, 
 which contains a tube for suction. 
 
 Feet. Tbese organs vary with the habits of life in dif- 
 ferent species. The limb consists of five divisions : the 
 coxa or hip, the trochanter, the femur or thigh, the tibia 
 or shank, and the tarsus or foot. This last has usually 
 five joints, but sometimes less. The Cdeoytera are subdi- 
 vided into groups, according as the tarsus consists of five, 
 four, or three segments. The last joint is furnished with 
 hooks or claws, and in the fly, etc., the foot is also 
 furnished with membranous expansions, called pulvilli. 
 These latter have numerous hairs, each of which has a 
 minute disk at its extremity. By these, probably by the 
 secretion of a viscid material, the insect is enabled to 
 walk on glass, etc., in opposition to gravity (Plate XVII, 
 Fig. 135). In the Dytiscus, tne inner side of the leg is 
 furnished with disks or suckers of considerable size. 
 They may be mounted as opaque objects. Stings and 
 Oi'i positors also present a great variety of structure, and 
 may be best mounted in balsam. 
 
 The alimentary canal in insects presents many diversi- 
 ties. As in higher animals, it is shorter in flesh-eaters 
 than in feeders on vegetables. It consists of: 1. The 
 oesophagus, which is sometimes dilated to form a crop. 
 
 2. The muscular stomach, or gizzard, whose lining mem- 
 brane is covered with plates, or teeth, for trituration. 
 
 3. A cylindrical true stomach, in which digestion takes 
 
 12 
 
178 THE MICROSCOPIST. 
 
 place. 4. The small intestine, terminating in 5, the large 
 intestine or colon. The colon of most insects in the 
 imago or perfect state, never in larvae or pupae, contains 
 from four to six organs of doubtful nature arranged in 
 pairs. They are transparent, round, or oval tubercles 
 projecting inside the colon, traversed by tufts of tracheae, 
 and sometimes with a horny ring at the base. 
 
 The salivary glands are sacs or tubes of variable form 
 and length, terminating near the mouth. A distinct liver 
 is absent, its function being performed by glandular cells 
 in the walls of the stomach. Many insects, however, 
 have caecal appendages to the stomach which secrete bile. 
 Some have tubular caeca appended to the small intestine, 
 probably representing a pancreas. In the interspaces of 
 the various abdominal organs, is found a curious organ 
 called the fatty body, which attains its development at 
 the close of the larval period, and appears to form a res- 
 ervoir of nourishment for the pupa. It consists of fat- 
 cells imbedded in a reticular tissue, and is traversed by 
 slender tracheae. 
 
 The Malpighian vessels are slender, mostly tubular 
 glands, caecal or uniting with each other, which open into 
 the pyloric end of the stomach, and as uric acid has been 
 found in them, are thought to serve the functions of a 
 kidney. Some consider the renal organ to be represented 
 by certain Jong vessels convoluted on the colon, and open- 
 ing near the anus. 
 
 Other glandular organs occur in insects, as cysts in the 
 integument, called glandulae odoriferae ; poison glands, 
 attached to the sting in many females; and silk-secreting 
 glands, coiled in the sides of the bod} 7 and opening out- 
 side the mouth. 
 
 The heart is a long contractile vessel situated in the 
 back. It is constricted at intervals. The posterior part 
 acts as a heart, and the anterior represents an aorta, and 
 conveys blood to the body. From the anterior end the 
 
THE MICROSCOPE IN ZOOLOGY. 179 
 
 olood passes in currents in all directions, without vascular 
 walls, running into the antennae, wings, extremities, etc., 
 and returning as a venous current, forming two lateral 
 currents towards the end of the ahdomen, it is brought 
 by the diastole of the heart through lateral fissures ex- 
 isting in it. 
 
 O 
 
 The respiration is effected by means of tracheae, two 
 or more large vessels running longitudinally, giving off 
 branches in all directions, and opening to the air by short 
 tubes, connected at the sides of the body with orifices 
 called spiracles. Aquatic larvae often have branchiae in 
 the form of plates, leaves, or hairs, through which the 
 tracheae ramify (Plate XVII, Fig. 136). 
 
 The nervous system consists of a series of ganglia ar- 
 ranged in pairs, one for each segment of the body. They 
 are situated between the alimentary canal and the under 
 surface of the body, and are usually connected by longi- 
 tudinal nervous cords. From the ganglia nerves are dis- 
 tributed to all parts. 
 
 The muscular system of insects is quite extensive. Ly- 
 onet dissected arid described more than four thousand in 
 the caterpillar of the goat-moth (Cossus ligniperda). 
 
 XVIII. ARACHNID A. This class of animals includes 
 mites, ticks, spiders, and scorpions. They are destitute 
 of antennae ; the head and thorax are united ; they have 
 simple eyes (ocelli), and eight jointed legs. 
 
 The cheese-mite, the u ticks," the itch-insect (Sarcoptes 
 scabies), and the Demodex folliculorum, which is parasitic 
 in the sebaceous follicles of the skin of the face, are com- 
 mon examples of Acari. They are best mounted in fluid. 
 
 The respiratory apparatus in spiders differs from that 
 of insects, the spiracles opening into respiratory sacs, which 
 contain leaf-like folds for aeration of blood. The spinning 
 apparatus is also interesting. 
 
 The minute anatomy of vertebrated animals affords the 
 
180 THE MICROSCOPIST. 
 
 microscopist numerous specimens, but the details will be 
 best understood from the following chapter. 
 
 As the classification of the Invertebrata is subject to 
 great variation, the following table, after Nicholson, is 
 added for the sake of comparison : 
 
 INVERTEBRATE ANIMALS. 
 
 SUB-KINGDOM I. PROTOZOA. 
 
 CLASS I. GREGARINID^E. Parasitic Protozoa, destitute 
 of a mouth, and destitute of pseudopodia. Ex., Gregarina. 
 
 CLASS II. RHIZOPODA. Simple or compound ; destitute 
 of a mouth ; capable of putting forth pseudopodia. 
 
 CLASS III. INFUSORIA. Generally with a mouth ; no 
 pseudopodia ; with vibratile cilia or contractile filaments. 
 
 SUB-KINGDOM II. CCELENTERATA. 
 
 CLASS I. HYDROZOA. Walls of the digestive sac not 
 separated from those of the body cavity ; reproductive 
 organs external. 
 
 Sub-class 1. Hydroida. Ex., Hydra. Tubularia (pipe- 
 coralline). Sertularia (sea-fir). 
 
 Sub-class 2. Siphonophora. Ex., Diphyes. Physalia 
 '(Portuguese man-of-war). 
 
 Sub-class 3. Discophom. Ex., Naked-eyed Medusae, or 
 Jelly-fish. 
 
 Sub-class 4. Lucernarida. Ex., Sea-nettles, or " Hidden- 
 eyed " Medusae. 
 
 CLASS II. ACTINOZOA. Digestive sac distinct from the 
 general cavity, but opening into it ; reproductive organs 
 internal. 
 
 Order 1. Zoantharia. Ex., Sea- Anemones (Actinia). 
 Reef-building corals. 
 
 Order 2. Alcyonaria. Ex., Sea-pen. Red coral. 
 
 Order 3. Ctenophora. Ex., Cestum (Yenus's girdle). 
 
THE MICROSCOPE IN ZOOLOGY. 181 
 
 SUB-KINGDOM III. ANNULOIDA. 
 
 CLASS I. ECHINODERM AT A. Integument calcareous or 
 leathery ; adult radiate. 
 
 Order 1. Crinoidea. Ex., Comatula. 
 
 Order 2. Blastoidea. (Extinct.) 
 
 Order 3. Cystoidea. (Extinct.) 
 
 Order 4. Ophiuroidea. Ex., Brittle-star. 
 
 Order 5. Asteroidea. Ex., Star-fish. 
 
 Order 6. Echinoidea. Ex., Sea-urchins. 
 
 Order 7. Holothuroidea. Ex., Sea-cucumbers. 
 
 CLASS II. SCOLECIDA. Soft-bodied, cylindrical, or flat ; 
 nervous system not radiate ; of one or two ganglia. 
 
 Order 1. Tceniada. Ex., Tapeworms. 
 
 Order 2. Trematoda. Ex., Flukes. 
 
 Order 3. Turbellaria Ex., Planarians. 
 
 Order 4. Acanthocephala. Ex., Echinorynchus. 
 
 Order 5. Gordiacea. Ex., Hairworms. 
 
 Order 6. Nematoda. Ex., Round worms. 
 
 Order 7. Eotifera. Ex., "Wheel animalcules. 
 
 SUB-KINGDOM IV. ANNULOSA. 
 
 DIVISION A. ANARTHROPODA. Locomotive appendages 
 not distinctly jointed or articulated to the body. 
 
 CLASS I. GEPHYREA. Ex., Spoon-worms. 
 
 CLASS II. ANNELIDA. Ex., Leeches (Hirundinidse). 
 Earth-worms (Oligochreta). Tube-worms (Tubicola). 
 Sand-worms and Sea-worms (Errantia). 
 
 CLASS III. CH.ETOGNATHA. Ex., Sagitta. 
 
 DIVISION B. ARTHROPODA Locomotive appendages 
 jointed to the body. 
 
 CLASS I. CRUSTACEA. Ex., Decapoda. Isopoda. Xi- 
 phosura. Cirri pedia. 
 
 CLASS II. ARACHNIDA. Ex., Podosomata (sea-spiders). 
 Acarina (mites). Pedipalpi (scorpions). Araneida (spi- 
 ders). 
 
182 THE MICROSCOPIST. 
 
 CLASS III. MYRIAPODA. Ex., Centipedes. 
 
 CLASS IV. INSECTA.- Ex., Anoplura (lice). Mallophaga 
 (bird lice). Thysanura (spring-tails). Hemiptera. Or- 
 thoptera. Neuroptera. Diptera. Lepidoptera. Hyme- 
 noptera. Coleoptera. 
 
 SUB-KINGDOM V. MOLLUSCA. 
 
 DIVISION A. MOLLUSCOIDA. A single ganglion, or pair 
 of ganglia ; heart imperfect, or none. 
 
 CLASS I. POLYZOA. Ex., Sea-mats (Flustra). 
 
 CLASS II. TUNICATA. Ex., Ascidia (Sea-squirts). 
 
 CLASS III. BRACHIOPODA. Ex., Terebratula. 
 
 DIVISION B. MOLLUSCA PROPER. Three pairs of gan- 
 glia ; heart of at least two chambers. 
 
 CLASS I. LAMELLIBRANCHIATA. Ex., Oyster. Mussel. 
 
 CLASS II. GASTEROPODA. Ex., Buccinium. Helix. 
 Doris. 
 
 CLASS III. PTEROPODA. Ex., Cleodora. 
 
 CLASS IY. CEPHALOPODA. 
 
 Order 1. Dibranchiata. Ex., Poulp. Paper Nautilus. 
 
 Order 2. Tetrabranchiata. Ex., Pearly Nautilus. 
 
 CHAPTER XII. 
 
 THE MICROSCOPE IN ANIMAL HISTOLOGY. 
 
 IN Chapter IX we described the elementary living 
 substance, or bioplasm, from which all organized struc- 
 tures proceed, with an outline of its morphology, chemis- 
 try, and physiology. In Chapter X we treated of Vege- 
 table Histology, or the elementary tissues and organs 
 which pertain to vegetable life. We now consider the 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 183 
 
 structure of formed material in animals, with special 
 reference to the minute anatomy of the human body. 
 Following the generalization of Dr. Beale, page 118, we 
 may classify histological structures as follows : 
 
 A. INORGANIC AND ORGANIC ELEMENTS OR PABULUM. 
 
 Eesultiug in 
 
 B. BIOPLASM ; or, 0. H. C. and N\, with other chemical 
 
 elements, plus. The cause of life. 
 From this results : 
 
 C. FORMED MATERIAL, consisting of, 
 
 I. CHEMICAL PRODUCTS ; Organic Compounds, etc. 
 
 II. MORPHOLOGICAL PRODUCTS. 1. Granules; 2. Globules; 
 
 3. Fibres ; 4. Membrane. 
 Forming Tissues. 1. Simple ; 2. Compound. 
 Arranged in Organs. 1. Vegetative ; 2. Animal. 
 
 I. THE CHEMICAL PRODUCTS of Bioplasm are very nu- 
 merous, and belong to the science of Histo-Chemistry. 
 Our plan allows us to do little more than to enumerate 
 the principal groups. It has already been stated that the 
 true chemical structure of bioplasm, or living sarcode, 
 (protoplasm in a living state) is unknown, since it is only 
 possible to analyze the dead cell substance. Of the rela- 
 tion of the oxygen, hydrogen, carbon, and nitrogen, etc., 
 which constitute its "physical basis," we can only specu- 
 late, or imagine. See Chemistry of Cells and their Products, 
 page l'2'2. 
 
 The chemical transformations of cell-substance into 
 " formed material " consist chiefly, with water and min- 
 eral matter, of certain groups of organic principles, some- 
 times called albuminous or " protein " substances, and 
 their nearer derivatives, as glut in-yielding and elastic 
 matter, with fat and pigments. These materials are sub- 
 ject to constant secondary changes or transformations, 
 
184 THE MICROSCOPIST. 
 
 since they are not laid down in the living body once for 
 all. They are also subject to constant decay, or ultimate 
 decomposition. Histo-Ckemistrynwat, therefore, be always 
 a difficult study, since we can rarely isolate the tissues for 
 examination, nor always tell when a substance is super- 
 fluous aliment, formative or retrogressive material. From 
 a limited number of formative or histogenic materials, we 
 have a host of changed or decomposition products. 
 
 Frey's Histology and Histo-Chemistry, Strieker's Hand- 
 Book of Histology, and Beale's Bioplasm, are among the 
 most useful books to the student in this department. 
 
 Frey subdivides the groups of organic principles as fol- 
 lows : 
 
 I. Albuminous or Protein Compounds. Albumen. Fi- 
 brin. Myosin. Casein. Globulin. Peptones. Ferments ? 
 
 II. Hcemoglobulin. 
 
 III. Formative (Histogenic) Derivatives from Albuminous 
 Substances. Keratin. Mucin. Colloid. Glutin-yielding 
 substances. Collagin and Glutin. Chondrigen and Chon- 
 drin. Elastin. 
 
 IY. Fatty Acids and Fats. Glycerin. Formic acid. 
 Acetic acid. Butyric acid. Capronic acid. Palmitic acid. 
 Stearic acid. Oleic acid. Cerebrin. Cholesterin. 
 
 V. Carbohydrates. The Grape-sugar group, Cane-sugar 
 group, and Cellulose group; or Glycogen. Dextrin. 
 Grape-sugar. Muscle-sugar. Sugar of milk. 
 
 YI. Non-Nitrogenous Acids. Lactic. Oxalic. Succinic. 
 Carbolic. Taurylic. 
 
 VII. Nitrogenous Acids. Inosinic. Uric. Hippuric. 
 Glycocholic. Taurocholic. 
 
 VIII. Amides, Amido Acids, and Organic Bases. Urea. 
 Guanin. Xanthin. Allantoin. Kreatin. Leucin. Ty- 
 rosin. Glycin. Cholin (JS"eurin). Taurin. Cystin. 
 
 IX. Animal Coloring Matters. Hsematin. ILemin. 
 Hrematoidin. Urohsematin. Melalin. Biliary pigments. 
 
 X. Cyanogen Compounds. Sulpho-cyanogen. 
 
^ 
 THE MICROSCOPE IN ANIMAL HISTOLOGY. 185 
 
 XL Mineral Constituents. Oxygen, Nitrogen, Carbonic 
 acid. Water. Hydrochloric acid. Silicic acid. Calcium 
 compounds (Phosphate, Carbonate, Chloride, and Fluor- 
 ide). Magnesium compounds (Phosphate. Carbonate. 
 Chloride). Sodium compounds (Chloride. Carbonate. 
 Phosphate. Sulphate). Potassium compounds (Chloride. 
 Carbonate. Phosphate. Sulphate). Salts of Ammonium 
 (Chloride. Carbonate). Iron and its Salts (Protochloride. 
 Phosphate). Manganese. Copper. 
 
 The subject of Histology relates properly to cell-struc- 
 ture (already described, Chapter IX), and its morpho- 
 logical products, yet its close connection with Histo-chem- 
 istry renders the foregoing list of substances valuable to 
 the student. 
 
 II. HISTOLOGICAL STRUCTURE is due to the formative 
 power of bioplasm, or living cell-substance, and is not mere 
 selection and separation from pabulum, or aliment, since 
 from the same pabulum, and, so far as we can see, under 
 the same circumstances, result tissues having different 
 physical and chemical properties. 
 
 In our classification we have arranged the microscopic, 
 or histological, elements of the tissues as Granules, Glob- 
 ules, Fibre, and Membrane. 
 
 Granules are minute particles of formed material. 
 
 Globules are small, homogeneous, round, or oval bodies. 
 If composed of albuminous matter they are rendered trans- 
 parent by acetic acid, and are dissolved by potash and 
 soda. If consisting of fat they are soluble in ether and 
 unaltered by acetic acid. If they are earthy matters they 
 are dissolved by acids and unchanged by alkalies. 
 
 Fibres appear as fine lines, cylindrical threads, or flat- 
 tened bands, parallel, or at various angles. 
 
 Membrane is an expansion of material. It may be trans- 
 parent and homogeneous, and may be recognized by plaits 
 or folds, which sometimes simulate fibres, or it may be 
 granular, or bear earthy particles. 
 
186 THE MICROSCOPIST. 
 
 From these elements result the simple and compound 
 tissues. 
 
 The Simple Tissues may be divided into 
 
 1. Cells with intermediate fluid, as Blood, Lymph, 
 Chyle, Mucus, and Pus. 
 
 2. Epithelium and its appendages. 
 
 3. Connective Substances. Cartilage. Fat. Connec- 
 tive tissue. Bone. Dentine. 
 
 The Compound Tissues are Muscle, Nerve, Gland, and 
 Vascular tissues. 
 
 These are formed into Organs. 
 
 1. Vegetative. The Circulatory, Respiratory, Diges- 
 tive, Urinary, and Generative organs. 
 
 2. Animal. The Bony, Muscular, Nervous, and Sensory 
 apparatus. 
 
 We shall attempt a brief description of these tissues 
 and organs, as illustrated by the microscope and modern 
 methods of research. 
 
 I. SIMPLE TISSUES. 
 
 1. CELLS WITH INTERMEDIATE FLUID. 
 
 ( 
 
 I. The Blood. 
 
 The microscope shows blood to consist, especially in 
 man and the higher animals, of red corpuscles, colorless 
 corpuscles, and the fluid in which they are suspended. 
 
 1. Blood Plasm.a, or Liquor Sanguinis. This is a color- 
 less and apparently structureless fluid, but when removed 
 from the body, fibrin separates from it in solid form. In 
 small quantities of blood this is seen in delicate fibres 
 crossing each other at various angles. 
 
 2. Red-blood Corpuscles. These were first discovered by 
 Swammerdam, in 1658, in frog's blood, and in that of man 
 by Lewenhoek, in 1673. Malpighi is said to have first 
 seen the actual circulation of blood in the web of a frog's 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 187 
 
 foot. The circulation may be readily observed by ether- 
 izing a frog, and expanding its foot by means of pins or 
 thread, upon -the stage of the microscope (Plate XVIII, 
 Fig. 137). The circulation may also be seen in the lung, 
 mesentery, or extended tongue, of the frog. 
 
 The red corpuscles of blood are flattened disks, which 
 are circular in Mammals, except the camel and lama, 
 which have elliptic disks. In birds, amphibia, and most 
 fishes, the disks are elliptic. In a few fishes (the cyclos- 
 tomata) they are circular. Their color depends on haemo- 
 globulin, which plays an important part in the exchange 
 of respiratory gases. In man the disks are usually double- 
 concave, with rounded edges. Out of the body they have 
 a tendency to adhere, or run together, in chains, like rolls 
 of coin (Plate XVIII, Fig. 138). In the elliptic disks of 
 birds, etc , there is a distinct nucleus. The size of the 
 disks varies. In man they are from 0.0045 to 0.0097 mil- 
 limetre. The smallest disks are in the Moschus Javanicus, 
 and the largest in Siren lacertina. In the latter they are 
 from y'g to ^ millimetre. 
 
 It is estimated that in a cubic millimetre (about ^th 
 of an inch) of human blood there are 5,000,000 red cor- 
 puscles, having a surface of 643 millimetres. 
 
 After a variable time from their removal from the ves- 
 sels they suffer contraction, and assume a stellate, or 
 mulberry form (Plate XVIII, Fig. 139). This occurs 
 more rapidly in feverish states of the system. On the 
 warm stage they suffer still greater alterations. Inden- 
 tations appear, which cause bead-like projections, some 
 of which become fragments, having molecular motion 
 (Plate XVIII, Fig. 139). The substance of red corpuscles 
 is elastic and extensible, and may be seen in the vessels to 
 elongate and curve so as to adapt themselves to the calibre 
 of the vessels. 
 
 Electric discharges through the red corpuscles produce 
 various changes of form. Alkalies dissolve, and acids 
 
188 THE M1CROSCOPIST. 
 
 cause a precipitate in them. They are tinged by neutral 
 solutions of carminate of ammonia. One-half to 1 per 
 cent, of salt added to the staining fluid causes the nuclei 
 only of Amphibian corpuscles to be stained. Chloroform, 
 tannin, and other reagents, produce various changes, 
 which suggest a wide field of research connected with 
 Therapeutics. 
 
 The old opinion of the structure of red corpuscles rep- 
 resented them as vesicles consisting of a membrane and its 
 contents, but Max Schultze, in 1861, showed that a mem- 
 brane was not constant. This may be verified by break- 
 ing them under pressure. 
 
 Brucke's experiment on the astringent action of boracic 
 acid on the blood of Triton, repeated by Strieker and Lan- 
 kester, shows the red corpuscles to possess a double struc- 
 ture. There is a body, called (Ecoid ; a porous, non-con- 
 tractile, soft, transparent mass ; and a retractile substance, 
 or Zooid, containing the hyemoglobulin, which fills the in- 
 terspaces of the (Ecoid. The Zooid seems identical with 
 simple cell-substance, or bioplasm. 
 
 3. Colorless, or White Corpuscles. These appear to be 
 simply masses of bioplasm of various sizes. Some are 
 quite small, and many are larger than the red corpuscles. 
 Their number is much smaller than the red disks, being 
 about 1 to 350, or even less. In leucaemia and other dis- 
 eases their relative number is much greater. In the blood 
 of cold-blooded animals, and in that of vertebrata, if the 
 normal temperature is continued by means of a warm 
 stage, the amoeboid motions are quite perceptible with a 
 high magnifying power (Plate XVIII, Fig. 139). They 
 may also be seen to take up small particles of matter into 
 their interior, such as cinnabar, carmine, milk-globules, 
 and even portions of the red globules. 
 
 Both red and white cells are forced through the unin- 
 jured walls of small vessels by impeded circulation, but 
 the white cells thus migrate, by virtue of their vital con- 
 
PLATE XVIII. 
 
 FIG. 137. 
 
 Capillary circulation in a portion of the 
 FIG. 138. 
 
 of a 
 
 Frog's foot. 
 FIG. 139 
 
 1 "*- 2 ^y u 1^* 
 
 Alterations in form in blood-discs : 1, Stellate or mul- 
 berry form; 2, On warm stage; 3, Amoeboid white-cell 
 forms. 
 
 FIG. 140. 
 
 Blood-discs : 1, Eliptic Discs of Amphibia : 
 2, Human red-corpuscles ; 3,White or lymph- 
 corpuscle ; 4, Rouleaux of red-discs. 
 
 FIG. 141. 
 
 Pus-corpuscles : a, with acetic acid. 
 FIG. 142. 
 
 
 
 Mucous corpuscles and epithelium. 
 
 Varieties of Epithelium : , Tessalated ; 6, Squamous; 
 c, Glandular; d, Columnar; e. Ciliated. 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 189 
 
 tractility, in the healthy body, and in greater numbers in 
 diseased states ; in some cases re-entering the lymphatic 
 circulation, and in others penetrating into various tissues. 
 The pus-corpuscles appearing in the vicinity of inflamed 
 parts are shown by this discovery, made by Waller and 
 Cohnheim, to be nothing but migratory lymphoid or 
 white cells of the blood. The change of form and place 
 of these amoeboid cells is readily seen by placing a drop of 
 frog's blood on a glass cover, and inverting it over a moist 
 cell. As it coagulates, a zone of serum extends round the 
 clot, in which the migrated cells will be found. 
 
 The colorless cells originate in the chyle and lymph- 
 systems, although some may come from the spleen and 
 the medulla of bones, multiplying in the blood itself, and 
 they pass into red corpuscles. Transitional forms have 
 been found in the general mass of blood, in the spleen, and 
 in the marrow of bones. 
 
 The white or colorless cells of blood are identical with 
 the cells of chyle, lymph, pus, mucus, and saliva. They 
 are often described under the term leucocytes (white cells.) 
 
 The leucocytes of saliva (salivary corpuscles) and of pus 
 contain granules or globules of formed material, which 
 exhibit for some time a peculiar dancing movement (see 
 page 120). 
 
 When at rest, or in a lifeless condition, the white cells 
 are of spheroidal form, and generally exhibit granules and 
 globules of fat. Acetic acid develops a nucleus, and some- 
 times splits it into several (Plate XVIII, Fig. 140). 
 
 II. Lymph and Chyle. 
 
 The vessels of the lymphatic or absorbent system re- 
 ceive the liquid part of the blood which has passed from 
 the capillaries, together with the products of decomposi- 
 tion in the tissues, and return them to the circulation. 
 The lymphatics of the intestinal canal receive during 
 
190 THE MICROSCOPIST. 
 
 digestion a mixture of albuminous and fatty matters, 
 which is known as chyle, and these vessels have obtained 
 the name of lacteals. The cells in this fluid are leucocytes, 
 identical with white cells in blood. They originate in the 
 lymphatic glands and "Peyer's patches" of the intestine, 
 and are the corpuscles of these organs which have been 
 carried off by the fluid stream. 
 
 III. Mucus. 
 
 Is a tenacious semifluid substance which covers the 
 surface of mucous membranes. It contains cast-oft' epi- 
 thelial and gland-cells, and the mucus corpuscle, which, as 
 we have before said, is identical with other leucocytes. 
 Synovial fluid is of similar nature. It is now regarded as 
 a transformation product of the epithelial cells, and not 
 to originate as a secretion from special glands (Plate 
 XVIII, Fig. 141). 
 
 2. EPITHELIUM AND ITS APPENDAGES. 
 
 Epithelium (from e/n, upon, and Oattw, to sprout) is so 
 called since it was formerly supposed to sprout from mem- 
 brane. It is a tissue formed of cells more or less closely 
 associated, which is found in layers upon external and 
 internal surfaces. The cells are generally transparent, 
 with vesicular, homogeneous, or granular nuclei, the lat- 
 ter being the remains of the original leucocyte or bio- 
 plast. In the older cells the nucleus is absent, the entire 
 mass having been transformed. 
 
 The forms of epithelial cells vary according to situation 
 or function. The original form is spheroidal, but changes 
 by compression, etc. 
 
 1. Tessellated or pavement epithelium (Plate XVIII, 
 a, Fig. 142). These are cells whose formed material is 
 flattened, and which are united at their edges. They are 
 sometimes hexagonal, and often polyhedral, in form. 
 
 Examples : Serous and synovial membranes ; the pos- 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 191 
 
 terior layer of the cornea ; the peritoneal surface ; the 
 interior of bloodvessels, and shut sacs generally. 
 
 2. Squamous or scaly epithelium. The cells are flat, 
 and overlap each other at the edges (Plate XVIII, 6, Fig. 
 142). 
 
 Examples : Epidermis ; many parts of mucous mem- 
 branes, as the mouth, fundus of bladder, vagina, etc. 
 
 3. Glandular epithelium (Plate XVIII, c, Fig. 142). 
 The cells are round or oval bioplasts, often polyhedral 
 from pressure, and the formed material is often soft. 
 
 Examples : Liver cells, convoluted tubes of kidney, and 
 interior of glands generally. 
 
 4. Columnar epithelium (Plate XVIII, d, Fig. 142). 
 Cells cylindrical or oblong, arranged side by side. A 
 bird's-eye view shows them similar to the tessellated form, 
 hence they should be seen from the side. 
 
 Examples : Villi and follicles of intestine, ducts of 
 glands, urethra, etc. 
 
 Some of the columnar or cylinder-cells have a thickened 
 border or lid perforated with minute pores (Plate XVIII, 
 /, Fig. 142). They are found in the small intestine, gall- 
 bladder, and biliary ducts. 
 
 5. Ciliated epithelium (Plate XVIII, e, Fig. 142). 
 These are cylindrical cells having vibratile cilia, whose 
 motions produce a current in the surrounding fluid. 
 
 Examples: The upper and back nasal passages, the 
 pharynx; bronchi, Fallopian tubes, etc. 
 
 The Hair. Hairs are filiform appendages, composed of 
 a modified epithelial tissue of rather complex structure. 
 They originate in a follicle, which is a folding in of the 
 skin. The shaft of the hair is the portion projecting 
 above the skin, and the root is concealed in the hair-fol- 
 licle. The bulb of the root is the rounded terminal part, 
 which is hollow below, and rests on a papilla which rises 
 from the floor of the follicle (Plate XIX, Fig. 143). Be- 
 tween the follicle and hair is a sheath, which is divided 
 
192 THE MICROSCOPIST. 
 
 into an external and internal portion. The cells of the 
 hair may be isolated by sulphuric acid or solution of soda. 
 They overlap each other like tiles, so as to present undu- 
 lating or jagged lines across the surface of a fresh hair. 
 The felting property of wool depends on the looseness of 
 this overlapping. Air-bubbles are often found in hair, 
 especially in the medullary or axial portion, and give a 
 silvery appearance to white hair. The granules of pig- 
 ment are generally found in the cortical portion. 
 
 Nails are nothing more than modified cuticle, depen- 
 dent for their growth -on the vessels of the matrix or bed 
 of the nail. Their epithelial cells may be demonstrated 
 by soaking in caustic soda or potash. 
 
 Corns, icarts, and horn have similar origin. 
 
 Enamel of the Teeth. The minute structure of dental 
 tissue will be described hereafter, but as the enamel is 
 generally considered to be of epithelial origin, some ac- 
 count of it belongs here. 
 
 O 
 
 The edge of the jaw is first marked by a slight groove, 
 known as the dental groove, and is covered with a thick 
 ridge of epithelium, called the dental ridge (Plate XIX, 
 Fig. 144, 1 a, 2 a). The epithelium grows down in a 
 process ' which has been called the enamel germ (1 d). 
 This becomes doubled by the upward growth of the 
 dental germ (2, 3,/), which originates from connective 
 tissue. The epithelial cells become transformed into 
 enamel columns or prisms. 
 
 3. CONNECTIVE SUBSTANCES OR TISSUES. 
 
 The term connective tissue has been given to a variety 
 of structures which probably start from the same rudi- 
 ments, and have a near connection with each other. It 
 is unfortunate that a name descriptive of function should 
 be applied to structure, yet the present state of histology 
 requires an account of substances thus called. 
 
 Connective tissues are all those which may be regarded 
 
PLATE XIX. 
 
 FIG. 143.* 
 
 FIG. 144. a. 
 
 Connective-tissue dement*. From the Frog's Thigh : 
 a, contracted cell; 6, ramified; c, d, motionless gran- 
 ular cells: /, fibrillse; g, connective-tissue bundle; 
 h, elastic fibre net-work. 
 
 Development of the enamel: a, dental ridg 
 b, young layer of epithelium; c, deep layer; 
 enamel germ ; e, enamel organ ; /, dental germ. 
 
 FIG. 146. 
 
 White Fibrous Tissue, from Ligament. 
 
 FIG. 147. 
 
 Yellow Fibrous Tissue, from Ligament um Nuchse 
 of Call. 
 
 FIG. 148. 
 
 Fatty Tissue. 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 193 
 
 as basement-membranes, supporting layers or investments 
 for epithelial structures, blood, lymph, muscle, and nerves. 
 It includes ordinary connective tissue (white and yellow 
 fibrous tissues), cartilage, bone, corneal tissue, dentine,, 
 and fatty tissue. 
 
 Most of the difficulty found in the consideration of 
 these tissues arises from discussions relative to the inter- 
 cellular substance. Max Schultze and Beale agree in re- 
 garding it to originate from the protoplasm or bioplasm 
 of cells. 
 
 The cells are, according to Frey, originally spheroidal y 
 with vesicular nuclei, and between them is an albuminous 
 intercellular substance a product of the cells, or trans- 
 formed cells which usually undergoes fibrillation, while 
 the cells become stunted, or develop into spindle-shaped 
 or stellate elements. Calcification of the intercellular sub- 
 stance occurs in some of these tissues, as bone and dentine. 
 
 The cells of connective tissue present many varieties. 
 Recklinghausen first observed migrating lymphoid cells 
 or bioplasts in the cornea of the eye, the tail of the tad- 
 pole, the peritoneum, and in various other places. The 
 exit of white corpuscles from the vascular walls renders 
 it probable that these amoeboid cells originate in the blood. 
 Granular cells, of various forms rounded, fusiform, and 
 stellate are also observed. Some of the stellate cells 
 give oft* anastomosing branches. Pigment cells, filled with 
 granular pigment, are also met with (Plate XIX, Fig. 
 145). 
 
 In its earliest stages, connective tissue consists of closely- 
 compressed cells, but in the adult two principal forms 
 have been distinguished ; first, those networks and trabec- 
 ul*e, developed from cells, which do not yield gelatin on 
 boiling, and, secondly, fibrillar connective tissue composed 
 of a gelatin-yielding substance. Of the first kind we notice 
 the following varieties : 
 
 1. Independent masses of gelatinous or mucous tissue, 
 
 13 
 
194 THE MICROSCOPIST. , 
 
 consisting of nucleated cells, giving off smooth anasto- 
 mosing trabeculae, as in the early stage of the vitreous 
 humor of the eye and of the gelatinous tissue of the um- 
 bilical cord, etc. 
 
 2. Very delicate reticular tissue found in the eye and in 
 the interior of nerve-centres. 
 
 3. A network filled with lymphoid cells (adenoid or 
 cytogenous tissue) in the glands of the lymphatic system, 
 and around the fasciculi of fibrillar connective tissue. 
 
 4. A coarser network in the ligamentum pectinatum 
 of the human eye. 
 
 5. A tissue formed of fusiform and stellate cells, as in 
 the interior of the kidneys 
 
 The second form referred to, or the fibrillar connective 
 tissue, was the only form to which the term connective 
 tissue was formerly applied. It is composed of gelatin- 
 yielding fibrillae, which may be split into skein-like por- 
 tions of various breadth. (Plate XIX, Fig. 146.) Per- 
 manganate of potash stains it brown. Acetic and dilute 
 mineral acids cause the tissue to swell so that the appear- 
 ance of fibrillation is lost through compression, and the 
 cells, or nuclei, are made manifest. Chloride of gold 
 staining exhibits both fibrillae and cells. 
 
 Mastic fibres (yellow elastic) (Plate XIX, Fig. 147) are 
 apparent in all forms of connective tissue which have been 
 made transparent by boiling, or acetic acid. They are 
 non-gelatinizing, cylindric, slightly branched, or forming 
 plexuses. In some fasciculi of fibrillar connective tissue, as 
 seen after the action of acetic acid, elastic fibres appear in, 
 hoops, or spirals, around them. In the ligamentum nu- 
 clese of the giraffe the elastic fibres are marked by trans- 
 verse striae, or cracks. Elastic fibres often form flattened 
 trabeculae, or are fused into elastic plates, or membranes, 
 with foraminae. as in arterial tunics. 
 
 The ligaments of the skeleton, the periosteum, peri- 
 chondrium, aponeuroses, fasciae, tendons, and generally all 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 195 
 
 the tunics of the body, afford examples of the fibrillar 
 connective tissue. 
 
 Fatty Tissue. The loose connective tissue contains in 
 various parts great numbers of cells filled with fat. Their 
 form is round, or oval, and are often divided into groups, 
 or lobules, by trabeculse. (Plate XIX, Fig. 148.) Each 
 lobule has its own system of bloodvessels, which divide 
 into such numerous capillaries that the smaller groups, 
 and even individual fat-cells, are surrounded by vascular 
 loops. Sometimes the contents of the cells appear in 
 needle-shaped crystals, often collected in a brush-like form. 
 Fat-cells seem to be chiefly receptacles for the deposit of 
 superabundant oleaginous nutriment, and are analogous 
 to the starch-cells in vegetables. 
 
 Cartilage. This is formed of cells in an originally homo- 
 geneous intercellular substance. The only difference be- 
 tween what was formerly distinguished as cartilage and 
 fibro-cartilas:e is that the matrix or intercellular substance 
 
 O 
 
 of the latter is fibrous. 
 
 The cells, or cartilage-corpuscles, are nucleated, and lie 
 in cavities of various sizes and form in the matrix (Plate 
 XX, Fig. 149). Two nuclei often appear in one cell. It 
 is yet a question whether the capsule and matrix are the 
 secretion of the cells which has become solid, or a part of 
 the body of the cell which has undergone metamorphosis. 
 
 The multiplication of cartilage-cells is endogenous. By 
 segmentation, two, four, or a whole generation of daughter- 
 cells, so called, may lie in the interior of a capsule. In this 
 way growing cartilage may acquire a great number of 
 elements. 
 
 In the ear of the mouse, etc., we observe a form of car- 
 tilage which is wholly cellular, and possesses no matrix 
 (Plate XX, Fig. 150). 
 
 Bone, or osseous tissue, is formed secondarily from meta- 
 morphosed descendants of cartilage or connective-tissue 
 cells, and is the most complex structure of this group. It 
 
196 THE MICROSCOPIST. 
 
 consists essentially of stellate ramifying spaces containing 
 cells, and a hard, solid, intermediate substance. The latter 
 is composed of glutinous material rendered hard by a mix- 
 ture of inorganic salts, chiefly of calcium. 
 
 As all bones are moulded first in cartilage it was natural 
 to conceive that they were developed by a transformation 
 of cartilage. Much variety of opinion still exists respect- 
 ing the process, but it is generally conceded that although 
 cartilage may undergo calcification, true bone is not formed 
 until the cartilage is dissolved, New generations of stel- 
 late cells appear in a matrix, which is first soft and then 
 calcified. New bone may also grow from the periosteum 
 by means of a stratum of cells called osteoblasts. The de- 
 tails of the process are too extensive for a treatise like the 
 present. If sections of growing bone are decalcified with 
 chromic acid and treated with carmine, the osteoblastic 
 layers and adjacent youngest bony layer acquire an in- 
 tensely red color, while the rest of the tissue, except the 
 bone-corpuscles, remains uncolored. 
 
 Fine sections cut from a long bone longitudinally and 
 transversely will show the microscopic structure, consist- 
 ing of the' Haver sian canals (Plate XX, Fig. 151, a) sur- 
 rounded with concentric lamella? of compact structure (6, b). 
 There are also intermediate and periosteal lamellae (<?, d). 
 The cavities containing the bone-cells, or bioplasts (<?, <?,) 
 are of various sizes, from 0.0181 to 0.0514 millimetres 
 long, and from these lacunae run the canaliculi in an irregu- 
 lar radiating course (/,/). In a balsam-mounted specimen 
 these hollows sometimes retain air, by which the structure 
 is rendered more apparent. 
 
 Dentine is the structure of which the teeth are most 
 largely composed. It consists of minute tubes filled with 
 bioplasm, which radiate from the central cavity of the 
 tooth, the interspaces between the tubes being solidified 
 by earthy salts so that the tissue is harder than bone. 
 
 Histologically a tooth may be said to be made of three 
 
PLATE 
 
 FIG. 149. 
 
 r : ~VN S^S 
 /i!&\ //fcA}: 
 
 FIG. 150. 
 
 Section of the Branchial Cartilage of Tadpole. 
 
 
 Longitudinal and transverse section of Bone: a, Haver- 
 sian canals; 6, concentric lamellae ; c, intermediate; d, 
 periostial lamellae; e, bone-cells; /, canaliculi. 
 
 FIG. 152. 
 
 FIG. 153. 
 
 Vertical section of Human 
 Molar Tooth: 1, enamel; 2, 
 cementumor crustapetrosa ; 
 3, dentine, or ivory; 4, osse- 
 ous excrescence,arising from 
 hypertrophy of cementum ; 
 5, pulp-cav'ity ; 6, osseous 
 lacuna? at outer part of den- 
 tine. 
 
 FIG. 154. 
 
 Striated Muscular-fibre, separated into fibrilhe 
 
 Involuntary Muscular-fibre. 
 
 Sarcolemma. 
 

 
 
THE MICKOSCOPE IN ANIMAL HISTOLOGY. 197 
 
 kinds of tissue: the cement, a bony substance, coating the 
 root of the tooth, containing bone-cells and canaliculi,but 
 no Haversian canals, the pulp in the central cavity of the 
 tooth serving for the nutrition of the organ, as a large 
 Haversian canal ; the dentine, or ivory, constructed as 
 above described; and the enamel, covering the crown, and 
 consisting of columns or prisms, often hexagonal, which 
 are the hardest and densest structures of the body (Plate 
 XX, Fig. 152). 
 
 The development of enamel from epithelium has been 
 referred to on page 192. The dental germ corresponds to 
 a papilla of the mucous membrane, and in an early stage 
 is covered by delicate stratified cells the dentine cells, 
 or odontoblasts which produce dentine. Teeth are thus 
 produced abnormally in other situations besides the jaws, 
 as in ovarian cysts, etc. 
 
 Before the development of the first, or milk teeth, the 
 rudiments of the permanent teeth exist as a fold or leaf 
 of epithelium springing from the enamel germ. 
 
 II. COMPOUND TISSUES. 
 
 1. Muscle. This is the tissue by which the principal 
 movements of the body are performed. It consists of 
 fibrin, which is endowed with special contractile power. 
 It is of two kinds, the voluntary, pertaining to organs of 
 voluntary motion, and the involuntary, found in situa- 
 tions which are not under the control of volition, as the 
 coats of bloodvessels, alimentary canal, uterus, and blad- 
 der. The fibres of voluntary muscles are marked with 
 transverse stride. Involuntary muscular fibres are smooth, 
 except in a few instances, as the fibres of the heart and 
 some of those in the oesophagus, which are striated. 
 
 The fibres are connected with and invested by connec- 
 tive tissue, and arranged in parallel sets, with vessels and 
 nerves in the intervals, and are attached to the parts they 
 
198 THE MICROSCOPIST. 
 
 are designed to move by tendon, aponeuroses, or some form 
 of fibrous tissue. The organs or muscles thus formed are 
 generally solid and elongated, but sometimes expanded. 
 
 Involuntary or unstriped muscular fibres are flat bands 
 or spindle-shaped fibres with nuclei, which may be re- 
 garded as the remains of the formative bioplasm (Plate 
 XX, Fig. 153). They are usually transverse, or interlace 
 with, each other on the walls of cavities and vessels. In 
 the heart the fibres, though involuntary, are striped and 
 branching. Striped fibre varies from e ' th to Y^^th inch 
 in diameter. It is largest in insects, in which individual 
 fibrils may be readily obtained, especially from the thoracic 
 muscles. They are generally found in bundles of fibrils, 
 splitting longitudinally or in disks, and each bundle is 
 inclosed in a sheath or sarcolemma (Plate XX, Fig. 154). 
 
 The transverse striation of muscle is subject to much 
 variation, and the precise nature of the sarcous elements 
 which produce the appearance is yet a matter of dispute, 
 but in all probability the ultimate elements are sarcous 
 prisms or particles imbedded in a homogeneous mass, and 
 by their mutual attraction, excited by various stimuli, 
 the contraction of the fibre takes place. 
 
 For the purpose of observation, the connective tissue 
 may be removed from muscular fibre by gelatinizing it 
 with dilute sulphuric acid, and dissolving it at a temper- 
 ature of 104 F. The nuclei of muscular fibre are seen 
 after treating with acetic acid, and may be stained with 
 carmine fluid, etc. 
 
 2. Nerve-tissue. The term nerve was applied by the 
 ancients to tense cords, as bow-strings, musical strings, 
 etc., and was appropriated to the fibres now called nerves, 
 because they deemed them to operate by tremors, vibra- 
 tions, or oscillations, another instance of wrong naming 
 of structure from an opinion respecting function. Hip- 
 pocrates, Galen, and others, however, thought nerves were 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 199 
 
 hollow tubes, conveying fine ethereal fluids, termed ani- 
 mal spirits. 
 
 Nervous matter is soft, unctuous, and easily disturbed, 
 hence it is necessary to examine it while fresh. Histo- 
 logically it is divided into fibres and cells, imbedded in 
 connective tissue. 
 
 Nerve-fibres are of two kinds, tbe medullated, or dark- 
 bordered threads, and the pale, or non-medullated. Med- 
 ullated fibres consist of a delicate envelope of connective 
 tissue, called the neurilemma or primitive sheath, an axis- 
 cylinder or albuminous portion, extending down the cen- 
 tre, and a portion composed of a mixture of albumen, 
 cerebral matter, and fat, surrounding the axis-cylinder 
 (Plate XXI, Fig. 155, A, B, c). This latter is the medul- 
 lary sheath, or white substance of Schwann. It changes 
 rapidly, so as to coagulate and become granular. Alka- 
 lies render it fluid, so as to exude in fat-like drops. Ab- 
 solute alcohol, chromate of potass and collodion, contract 
 the sheath, so as to permit the axis-cylinder, which is the 
 essential part of the nerve, to protrude (Plate XXI, E, 
 Fig. 155). Anilin, carmine, nitrate of silver, and chloride 
 of gold stain the axis-, while osmic acid blackens only the 
 medullary sheath. 
 
 Non-medullary or pale nerve-fibres are regarded as em- 
 bryonic or developmental forms (Plate XXI, D, Fig. 155). 
 The ganglionic fibres of the sympathetic (Remak's fibres) 
 are flat, homogeneous bands, with round or oval nuclei. 
 Some have considered them as formed of connective tis- 
 sue, but their nervous character is generally conceded. 
 
 Schultze and others regard the axis-cylinder as made up 
 of extremely delicate fibrillse. 
 
 Nerve-cells, or ganglion corpuscles, are of two kinds, 
 those without and those with processes. The first are 
 called apolar, and the latter unipolar, bipolar, or multi- 
 polar, according to the number of ramifications. The 
 cells are nucleated, and inside the nucleus is usually 
 
"200 THE MICROSCOPIST. 
 
 another, the nucleolus. Dr. Beale discovered certain gan- 
 glion-cells in the sympathetic of the tree-frog (in the au- 
 ricular septum of the heart), one of whose poles is encir- 
 cled spirally by the others (Plate XXI, Fig. 156). 
 
 The ultimate structure of ganglia or nervous knots, 
 and the relation of the fibres to the cells, opens a wide 
 field of research. In the muscle of the heart, etc., many 
 of these ganglia seem to form special nervous systems. 
 Dr. Beale has described the nerves ramifying on the capil- 
 laries and involuntary muscular fibrils of the terminal ar- 
 teries as a self-regulating mechanism for the distribution 
 of blood (Plate XXI, Fig. 157). Thus, if a tissue receives 
 excess of pabulum, the capillary nerve-fibre is disturbed 
 and transmits a change to the ganglion, and thence 
 through the efferent nerve to the muscular fibres of the 
 artery, and vice versa. 
 
 Meissner has shown many ganglionic plexuses in the 
 submucous coat of the alimentary canal. Another system 
 of the same kind, called the plexus myentericus, was dis- 
 covered by Auerbach between the muscular layers of the 
 intestinal tube. Similar plexuses exist in other organs. 
 
 As to the peripheral termination of nerve-fibres, there 
 is still considerable discussion. Most of the German his- 
 tologists consider the nerves of voluntary muscles to ter- 
 minate in end plates, in which the neurilemma becomes 
 continuous with the sarcolemma of the muscular fibre. 
 Dr. Beale maintains that there is a plexus of minute nerves 
 over the fibrils. In some of my own preparations, espe- 
 cially some stained with soluble Prussian blue, a disk 
 formed of a plexus of excessively minute nerve-fibres is 
 observed, from which tortuous branches go to other mus- 
 cle-fibres. 
 
 In the cornea, Cohnheim and Klein have traced fine 
 nerve-fibres to the epithelial cells of the conjunctiva, by 
 means of chloride of gold staining. 
 
 3. Glandular tissue consists of a fine transparent mem- 
 
PLATE XXI. 
 
 FIG. 155. 
 
 FIG. 156. 
 
 Various Ganglionic Nerve-cells. 
 
 FIG. 157. 
 
 Nerve-fibres. 
 
 Self-regulating System of Ganglia nervt 
 arteries, and capillaries. 
 
 FIG. 160. 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 201 
 
 brane, through which the plasma transudes, and cells of 
 glandular epithelium. A vascular network exists on the 
 surface of the membrane, from which the material of the 
 secretion is obtained. This membrane may be a simple 
 follicle, or tube, as in the mucous membrane, or system of 
 tubes, as in the kidneys, a convoluted tube, a simple open 
 vesicle, a racemose aggregation of vesicles, or a close cap- 
 sule which discharges itself by bursting. (Plate XXI, 
 Fig. 158). 
 
 4. Vascular Tissue. The smallest bloodvessels and lym- 
 phatics, called capillaries, are minute tubes, consisting of a 
 series of flattened epithelial cells, and containing stomata, 
 or openings through which white or red blood-corpuscles 
 may occasionally pass (Plate XX, Fig. 159, a, 6). The 
 larger trunks have, in addition to the cellular layer, one 
 of longitudinally striated connective tissue, a middle coat 
 containing transverse muscular fibres, and an external coat 
 of connective tissue (Plate XXI, Fig. 159). The distribu- 
 tion of the capillary bloodvessels is various, according to 
 the nature or function of the organ or tissue in which they 
 are found. 
 
 DEVELOPMENT OF THE TISSUES. 
 
 It has been stated, page 125, that reproduction in the 
 higher animals consists of an ovum fecundated by contact 
 with a sperm-cell, or spermatozoid. The ovum consists 
 of a germinal vesicle, containing one or more germinal spots, 
 and included within a vitellus (a yelk) which is surrounded 
 by a vitelline membrane, which may have additional invest- 
 ments in the form of layers of albumen and of an outer 
 coriaceous or calcified shell. 
 
 The first step in the development of the embryo is the 
 division of the vitelline substance into cleavage-masses, at 
 first two, then four, then eight, etc. This process of yelk- 
 division may affect the whole yelk or a part of it, and re- 
 sults in the formation of a blastoderm, or embryogenie 
 
202 THE MICROSCOPIST. 
 
 tissue. This rudimentary embryonic tissue consists of 
 three layers of cells, or germinal plates. The upper is the 
 corneous layer, or epiblast, the middle one the intermediate 
 plate, or mesohlast, and the lower the intestinal glandular 
 layer, or hypoblast (Plate XXI, Fig. 160). From these 
 the various tissues and organs are developed. 
 
 The outer plate produces the epithelium of the skin and 
 its appendages, with the cellular elements of the glands of 
 the skin, mammse, and lachrymal organs. T>y a peculiar 
 folding over the axis this plate also produces the elements 
 of the brain and spinal cord, and the internal parts of the 
 organs of special sense. The physiological significance of 
 this layer is, therefore, very great. 
 
 The lower stratum of the blastoderm supplies the epi- 
 thelium of the digestive tract, and the cellular constituents 
 of its various glands, together with the liver, lungs, and 
 pancreas. 
 
 The middle layer supplies the material for many struc- 
 tures. The whole group of connective substances, or 
 tissues of support; muscular tissue; blood and lymph, 
 with their containing vessels ; lymph-glands, including 
 the spleen, etc., all arise from this. The epithelial cells 
 of such tubes and cavities as originate in this layer are 
 regarded as different from those of true glands, and are 
 more permeable to fluids. They have been termed false 
 epithelium, or endothelium. 
 
 The following description, by Professor Huxley, will 
 enable the student to form an idea of the general process 
 of development. A linear depression, the primitive groove, 
 makes its appearance on the surface of the blastoderm, 
 arid the substance of the mesoblast along each side of this 
 groove grows up, carrying with it the superjacent epiblast. 
 Thus are produced the two dorsal lamince, the free edges 
 of which arch over toward one another, and eventually 
 unite, so as to convert the primitive groove into the cere- 
 bro-spinal canal. The portion of the epiblast which lines 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 203 
 
 this, cut off from the rest, becomes thickened, and takes 
 on the structure of the brain, or encephalon, in the region 
 of the head ; and of the spinal cord, or myelon, in the 
 region of the spine. The rest of the epiblast is converted 
 into the epidermis. 
 
 The part of the blastoderm which lies external to the 
 dorsal laminse forms the ventral lamince; and these bend 
 downward and inward, at a short distance on either side 
 of the dorsal tube, to become the walls of a ventral or 
 visceral tube. The ventral laminae carry the epiblast on 
 their outer surfaces, and the hypoblast on their inner sur- 
 faces, and thus, in most cases, tend to constrict off the 
 central from the peripheral portions of the blastoderm. 
 The latter, extending over the yelk, incloses it in a kind 
 of bag. This bag is the first formed and the most con- 
 stant of the temporary, or foetal appendages of the young 
 vertebrate, the umbilical vesicle. 
 
 AYhile these changes are occurring, the mesoblast splits, 
 throughout the regions of the thorax and abdomen, from 
 its ventral margin, nearly up to the notochord (which has 
 been developed, in the meanwhile, by histological differen- 
 tiation of the axial indifferent tissue, immediately under 
 the floor of the primitive groove) into two lamella?. One 
 of these, the visceral lamella, remains closely adherent to 
 the hypoblast, forming with it the splanchnopleure, and 
 eventually becomes the proper wall of the enteric canal ; 
 while the other, the parietal lamella, follows the epiblast, 
 forming with it the somatopleure, which is converted into 
 the parietes of the thorax and abdomen. The point of 
 the middle line of the abdomen at which the somato- 
 pleures eventually unite, is the umbilicus. 
 
 The walls of the cavity formed by the splitting of the 
 ventral laminae acquire an epithelial lining, and become 
 the great pleuro peritoneal serous membranes (Huxley's 
 Anatomy of Vertebrated Animals). 
 
 In addition to the umbilical vesicle, above described as 
 
204 THE MICROSCOPIST. 
 
 a temporary appendage, the foetus has other special struc- 
 tures, derived from the blastoderm. Thus the somato- 
 pleure grows up over the embryo and forms a sac filled 
 with clear fluid, the amnion. The outer layer of the sac 
 coalesces with the vitelline membrane to form the chorion. 
 The atlantois begins as an outgrowth from the mesoblast. 
 It becomes a vesicle, and receives the ducts of the primor- 
 dial kidneys or Wolffian bodies, and is supplied with blood 
 from the two hypogastric arteries which spring from the 
 aorta. The allantois is afterwards cast off by the contrac- 
 tion of its pedicle, but a part of its root is usually re- 
 tained, and becomes the permanent urinary bladder. In 
 the Mammalia the allantois conveys the embryonic ves- 
 sels to the internal surface of the chorion, whence they 
 draw supplies from the vascular lining of the uterus. 
 
 Foster and Balfour recommend that the study of em- 
 bryonic development should commence with the egg of a 
 fowl taken at different times from a brooding hen, or an 
 artificial incubator. The egg should be placed on a hol- 
 low mould of lead in a basin, and covered with a warm 
 solution of salt (7.5 per cent.). It should be opened with 
 a blow, or by filing the shell. With the naked eye or 
 simple lens, lying across the long axis of the egg, may be 
 seen the pellucid area, in which the embryo appears as a 
 white streak. The mottled vascular area, with the blood- 
 vessels, and the opaque area spreading over the yelk, may 
 be observed. The blastoderm may be cut out with a sharp 
 pair of fine scissors, floated into a watch-glass, freed from 
 vitelline membrane and yelk, and removed (under the salt 
 solution) to a glass slide. A thin ring of putty may then 
 be placed round the blastoderm, which is covered with 
 salt solution, and the thin glass cover put on. With a 
 low-power objective many of the details of structure may 
 be seen in an embryo of thirty-six to forty-eight hours 
 incubation, as the heart, the neural tube, the first cere- 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 205 
 
 bral vesicles, the folds of the somatopleure and splanch- 
 nopieure, the provertebrre, etc. 
 
 To prepare sections of the embryo, it must be first hard- 
 ened by placing the slide containing it in a solution of 1 
 per cent, chromic acid for twenty-four hours. From this 
 it should be removed to one of 3 per cent, for twenty-four 
 hours more ; then for a similar time in alcohol of 70 per 
 cent., then in alcohol of 90 per cent., and lastly in abso- 
 lute alcohol, where it may remain till required for section. 
 Sometimes picric or osmic acid is used for hardening. 
 The embryo may be stained by placing it in Beale's car- 
 mine fluid for twenty-four hours, and then replacing it in 
 absolute alcohol for a day before it is cut. It may also 
 be stained with hsematoxylin if preferred. The specimen 
 may be imbedded in paraffin, wax, and oil, or a mixture 
 of four parts of spermaceti to one part of cocoa butter or 
 castor oil. If there are cavities in the object, it is best 
 to saturate it first with oil of bergamot. A little melted 
 spermaceti mixture is poured on the bottom of a small 
 paper box, and when solid the embryo is placed flat on 
 it, the superfluous oil removed as far as possible, and the 
 warm mixture poured on. Bubbles can be removed with 
 a hot needle. A mark should be made of the exact posi- 
 tion of the embryo. (Sections may be cat with the sec- 
 tion-cutter or a sharp razor, and if the spermaceti mix- 
 ture is used, the razor should be moistened w r ith olive oil. 
 The sections should be floated from the razor to the slide, 
 and treated with a mixture of four parts turpentine and 
 one of creasote. They may then be mounted in balsam 
 or dammar varnish. 
 
 The most instructive transverse sections of an early 
 embryo will be through the optic vesicles, the hind brain, 
 the middle of the heart, the point of divergence of the 
 splanchnopleure folds, the dorsal region, and a point where 
 the medullary canal is still open. For the unincubated 
 blastoderm only one section, through the centre, is re- 
 
206 THE MICROSCOPIST. 
 
 quired to show the formative layers. In the later stages 
 dissection is required, and is best performed with embryo 
 preserved in spirit. If living embryos are placed in spirit, 
 a natural injection of the vessels may be obtained. 
 
 III. OEGA^S OF THE BODY. 
 
 Anatomists usually group the organs into systems, as 
 the osseous, muscular, nervous, vascular systems, etc., but 
 for histological study a classification based on physiologi- 
 cal considerations may be more convenient for the student. 
 
 I. VEGETATIVE ORGANS. 
 
 1. Nutritive, or organs pertaining to the absorption and 
 distribution of pabulum, including the digestive and cir- 
 culatory organs. 
 
 The mucous membrane of the intestinal canal contains 
 many follicles and glands, whose secretions serve impor- 
 tant offices in the preparation of the food. These will be 
 referred to in the next section. The epithelium of the 
 intestinal canal is columnar, except in the oesophagus, 
 where it is laminated. Beneath the glandular lajw of 
 the stomach is a stratum of fibrous connective tissue and 
 muscle fibres in two layers, an internal with transverse, 
 and an external with longitudinal fibres. The tissue of 
 the small intestine beneath the epithelium is reticular 
 connective, entangling lymphoid cells. The structure of 
 the large intestine is similar to that of the stomach. The 
 villi of the small intestine begins at the pylorus, flat and 
 low at first, but becoming conical, and finally finger-like 
 in shape. The epithelium of the villi are columnar, with 
 a thickened and perforated edge (Plate XXII, Fig. 161). 
 Between the epithelial cells of the villi, peculiar " goblet- 
 cells" are often found, which Frey supposes to be decay- 
 ing cells. The reticular connective tissue of each villus 
 is traversed by a vascular network, a lymphatic canal or 
 lacteal, and delicate longitudinal muscular fibres. If the 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 207 
 
 villas is unusually broad, there may be more tbau one 
 lacteal. The lacteals absorb the fluid known as chyle. 
 They are blind ducts, and nitrate of silver injections show 
 them to have the same structure as other lymphatics. 
 
 The lymphatic radicles are widely disseminated through 
 all the tissues and organs of the body. They take up nu- 
 tritive fluids, either from the alimentary canal,, or such as 
 have transuded from the capillaries into the interstices of 
 the body, mingled with the products of decomposition, 
 and. convey them into the general circulation. Hyrtl's 
 method of demonstrating these radicles is by passing a 
 fine canula into the tissue containing lymphatics and forc- 
 ing the injection by gentle pressure. They are either net- 
 works, analogous to capillaries, or blind passages which 
 unite in reticulations. The structure of the vessels has 
 already been described, page 201. Lymphatics and capil- 
 laries do not communicate directly. A lymph-canal may 
 be surrounded by capillaries, or run alongside of a capil- 
 lary, or a lymphatic sheath may envelop a bloodvessel. 
 This latter plan is seen in the nervous centres, and has 
 been called by His the perivascidar canal system. 
 
 The larger lymphatic trunks are interrupted by nodular 
 and very vascular organs, the lymphatic glands. These 
 consist of the reticular connective tissue already described, 
 surrounded by an envelope of ordinary fibrous tissue. One 
 or more afferent lymphatic vessels penetrate the capsule, 
 or envelope, and similar efferent vessels make their exit 
 from the other side. Frey describes these glands as con- 
 sisting of a cortical portion, follicles, and a medullary 
 portion composed of the tubes and reticular prolongations 
 of the follicles (Plate XXII, Fig. 162). There is a com- 
 plicate system of communication between the follicles. 
 The afferent vessel opens into the investing spaces of the 
 follicle. These lead into the lymph-passages of the med- 
 ullary portion, from the confluence of which the radicles 
 of the efferent vessels are formed. The lingual follicular 
 
208 THE MICROSCOPIST. 
 
 glands and tonsils, the solitary and agmiuated glands of 
 the intestine (Peyer's patches), the thymus, and the spleen 
 have a similar structure, and are called lymphoid organs. 
 
 In the thoracic duct the epithelium is inclosed in several 
 layers of fibrous membrane. The latter contains trans- 
 verse muscular fibres. The heart, although an involuntary 
 muscular organ, has striated muscular fibres. These fibres 
 are not, like other striped muscles, collected into bundles, 
 but are reticular. The heart, like other organs, is supplied 
 with lymphatics and bloodvessels. The cardiac plexus- of 
 nerves consists of branches from the vagus and sympa- 
 thetic. Numerous microscopic nervous ganglia also occur, 
 especially near the transverse groove and septum of the 
 ventricles. It is thought that these are the chief centres 
 of energy, so that the heart pulsates after its removal from 
 the body. It has also been shown recently that the sym 
 pathetic and vagus filaments are in antagonism, so that 
 stimulation of the vagus interrupts the motor influence of 
 the sympathetic, and may bring the heart to a standstill 
 in a condition of diastole. 
 
 The structure of bloodvessels has been described under 
 the head of vascular tissue. No special boundary exists 
 between capillaries and the arteries and veins. The ar- 
 rangement of the capillaries, however, is various, and 
 often so characteristic that a practiced eye can generally 
 recognize an organ or tissue from its injected capillaries. 
 (Plate XXII, Figs. 163 to 168.) For methods of inject- 
 ing, see page 64. Capillaries form either longitudinal or 
 rounded meshes. The muscular network, etc. , is extended, 
 while fat-cells, the alveoli of the lungs, lobules of liver, 
 capillary loops of papillae in skin and mucous membranes, 
 outlets of follicles, etc., present a more or less circular in- 
 terlacement. The capillary tube lies external to the ele- 
 mentary structure, and never penetrates its interior. 
 
 2. Secretive Organs. True secretions serve important 
 offices in the organism : as the materials of reproduction ; 
 
PLATE XXII, 
 
 FIG. 162. 
 
 FIG. 161. 
 
 Intestinal Villas. 
 
 FIG. 163. 
 
 Lymphatic Gland. 
 FIG. 164. 
 
 Capillary net-work around Fat-cells. 
 FIG. 165. 
 
 Capillary uet-work of Alusdt. 
 FIG. 166. 
 
 Distribution of Capillaries 
 in Mucous Membrane. 
 
 FIG. 167. 
 
 Distribution of Capillary bloodvessels, 
 in Sfci no/ Finger. 
 
 FIG. 168. 
 
 Villi of Small Intestine of Monkey. 
 
 Arrangement of the Capillaries of the air-cells of 
 the Human Lung. 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 209 
 
 milk from the mammary gland; saliva, gastric juice and 
 pancreatic fluid for digestion ; mucus, sebaceous matter, 
 tears, etc. Excretions result from waste or decomposi- 
 tion, and are incapable of further use; as carbonic acid, 
 separated by the lungs ; urea, uric acid, etc., by the kid- 
 neys ; saline matters, from kidneys and skin ; lactic acid, 
 portions of bile, and some of the components of faeces. 
 
 The sweat glands in the skin are simply convoluted tubes 
 lined with glandular epithelium and surrounded by a 
 basket-like plexus of capillaries. The sebaceous glands are 
 racemose, and often open into the hair-follicles. 
 
 The salivary glands are complex mucous glands, and 
 the saliva secreted by them is a complex mixture. The 
 terminal nerves of the submaxillary gland have been traced 
 to the nuclei of the gland-cells. 
 
 The lingual glands, and parotid, partake of the nature 
 of lymphoid organs. The glands of the oesophagus are 
 racemose. In the stomach there are two kinds, the peptic, 
 and gastric mucous glands. The peptic glands are blind 
 tubes closely crowded together over the mucous mem- 
 brane, lined with columnar epithelium near their open- 
 ings, and gland-cells below. The mucous glands are nu- 
 merous near the pylorus, and are usually branching tubes. 
 The capillaries are arranged in long meshes about the 
 peptic glands, and form a delicate network in the submu- 
 cous tissue. Xumerous lymphatic radicles communicate 
 with lymph-vessels below the peptic glands. 
 
 The small intestine contains the racemose glands of 
 Brunner and the tubular follicles of Lieberkuhn, together 
 with the lymphoid follicles known as the solitary and 
 agminated glands of Peyer. The glands of Brunner are 
 confined to the duodenum, and their excretory duct and 
 gland vesicle are lined by columnar epithelium. Lieber- 
 kuhn's follicles are found in great numbers all over the 
 small intestine. Peyer's patches are most numerous in 
 the ileum. They are accumulations of solitary glands, 
 
 14 
 
210 THE MICROSCOPIST. 
 
 and their structure is similar to the follicles of a lymphatic 
 gland. The gland vesicles of the pancreas are roundish, 
 and like other salivary glands it is invested with a vascu- 
 lar network with rounded meshes. 
 
 The liver is the largest gland connected with nutrition. 
 Few animals are without a liver or its structural equiva- 
 lent. In polyps the liver is represented by colored cells 
 in the walls of the stomach cavity. In annelids the biliary 
 cells cluster round csecal prolongations of the digestive 
 cavity. In Crustacea the liver consists of follicles, and in 
 insects of tubes, opening into the intestine. In all cases 
 the essential elements are glandular cells containing col- 
 oring matter, oil, etc. In vertebrates some parts of the 
 structure have not been decided upon without controversy. 
 
 In man the liver is a large, solid, reddish-brown gland, 
 about twelve inches across, and six or seven inches from 
 anterior to posterior edge, and weighing three or four 
 pounds, situated in the right hypochondrium, and reach- 
 ing over to the left. It is divisible into right and left 
 lobes by the broad peritoneal ligament above, and the 
 longitudinal fissure beneath. From the latter a groove 
 passes transversely on the right side, lodging the biliary 
 ducts, sinus of the portal vein, hepatic artery, lymphatics, 
 and nerves, which are enveloped in areolar tissue, called 
 the capsule of Glisson. From this groove ramifications 
 of the portal canal extend through the liver, so numerous 
 that no part of the hepatic substance is further than one- 
 thirtieth of an inch from them. These ramifications 
 carry the branches of the portal vein from which the 
 capillary plexus surrounding the lobules begin, together 
 with the bile-ducts, hepatic artery, etc. 
 
 The hepatic lobules are readily distinguished by the 
 naked eye in many mammals, as the hog, but less easily 
 in human liver. They consist essentially of innumerable 
 gland-cells, and a complex network of vessels which tend 
 towards the centre of the lobule, where their confluence 
 
PLATE XXIII. 
 
 FIG. 169. 
 
 FIG. 170. 
 
 Lobule of Liver. 
 
 Uriniferous Tubes of Kidney. 
 
 FIG. 173. 
 
 Tactile Papillae. 
 
 Blood-vessels of Kidney. 
 
 FIG. 174. 
 
 FIG. 172. 
 
 Alveoli of Lung. 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 211 
 
 forms the radicle of the hepatic vein ; while externally 
 the lobules are bounded by branches of the portal vein 
 and biliary canals (Plate XXIII, Fig. 169). The hepatic 
 artery nourishes the proper connective tissue of the organ, 
 and its venous radicles return the blood to the portal 
 vein. The liver or bile-cells lie between the meshes of 
 the capillaries, and are irregularly polyhedral from pres- 
 sure, soft, granular, and nucleated. Brown pigment-gran- 
 ules and fatty globules are also found in the cells, and in 
 disease in increased quantity. These bile-cells are inclosed 
 in a delicate reticulated membrane, and Hering considers 
 them to have a plexus of fine bile-ducts around them. 
 
 Tl>e kidneys are two large bean-shaped organs, each 
 covered with a thin but strong fibrous envelope or tunic, 
 which is continuous round the organ to the hilus, where 
 the ureter leaves the gland and the bloodvessels enter. 
 Even with the naked eye we may distinguish in a section 
 of kidney the external granular cortex and the fibrous or 
 striped medullary portion. The lines of the latter con- 
 verge towards the hilus, and generally in a single conoid 
 mass ; but in man and some other animals this is divided 
 into sections, called the pyramids, and between them the 
 cortical substance is prolonged in the form of septae, while 
 both portions contain interstitial connective tissue. Both 
 the cortical and medullary portions contain long branch- 
 ing glandular tubes, called the uriniferous tubes. In the 
 medullary part these tubes are straight and divide at 
 acute angles, while in the cortex they are greatly convo- 
 luted and terminate in blind dilatations, the capsules of 
 Bowman. Staining with nitrate of silver shows the cap- 
 sules to be lined with delicate pavement-epithelium. The 
 convoluted tubes proceeding from the capsules, containing 
 thick granular gland-cells, after numerous windings in the 
 cortex, arrive at the medullary portion, where each pur- 
 sues a straight course, and is lined with flat pavement- 
 epithelium similar to the endothelium of vascular tissue. 
 
212 THE MICROSCOPIST. 
 
 Tear the base of the pyramids these tubes curve upwards, 
 forming the looped tubes of Henle. The recurrent tubes 
 enlarge, and exhibit the ordinary cubical gland-cell. 
 These tubes also become more tortuous, and empty into 
 others of larger calibre, called collecting tubes. These 
 are lined with low columnar epithelium, and uniting with 
 similar tubes at acute angles, give exit to the urine at the 
 apex of the papillae in the pyramids (Plate XXIII, Fig. 
 170). 
 
 The bloodvessels of the kidney are as complex as the 
 glandular tissue. Both vein and artery enter at the hilus 
 of the kidney, and after giving twigs to the external 
 tunic, proceed between the pyramids as far as their bases. 
 Here they give off curving branches, forming imperfect 
 arches among the arteries, and complete anastomosing 
 rings on the veins. From the arterial arches spring the 
 branches which bear the glomeruli of the cortical sub- 
 stance or Malpighian tufts (Plate XXIII, a, Fig. 171). 
 The afferent vessel of the glomerulus subdivides, and after 
 coiling and twisting within the capsule of Bowman, gives 
 origin to the efferent vessel, by the union of the small 
 branches thus formed. This efferent vessel breaks up into 
 a network of fine capillaries, with elongated meshes sur- 
 rounding the straight uriniferous canals. From the periph- 
 ery of this network somewhat wider tubes are given off, 
 which surround with rounded meshes the convoluted tubes 
 of the cortex. 
 
 The long bundles of vessels between the uriniferous tubes 
 of the medulla, communicating in loops or forming a deli- 
 cate network round the mouths of the canals at the apex 
 of the papillae are called the vasa recta. 
 
 The ureters, like the pelvis of the kidney, consist of an 
 external fibrous tunic, a middle layer of smooth muscular 
 fibres, and an internal mucous membrane with a layer of 
 epithelium. The bladder is covered externally with a 
 serous membrane, the peritoneum. The female urethra is 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 213 
 
 lined by mucous membrane, with vascular walls full of 
 folds, and containing, near the bladder, a number of mu- 
 cous glands. 
 
 3. Respiratory Organs. The lungs receive air by the 
 trachea and venous blood from the right side of the heart 
 to transmit to the left side. They may be compared, as 
 to form and development, to racemose glands. The ex- 
 cretory ducts are represented by the bronchial ramifica- 
 tions, and the acini by the air-vesicles. 
 
 The ciliated mucous membrane of the bronchial twigs 
 gradually loses its laminated structure until only a single 
 layer remains. Tbeir muscular layer also ceases before 
 arriving at the air-cells. At the end of the last bronchial 
 tubules we find thin-walled canals called alveolar passages. 
 These are again subdivided and end in peculiar dilatations 
 called primary pulmonary lobules, or infandibula (Plate 
 XXIII, Fig. 172). The air-cells, vesicles, or alveoli, are 
 saccular dilatations in the walls of the primary lobules, 
 opening directly into a common cavity. Their walls con- 
 sist of delicate membrane of connective tissue, often con- 
 taining black pigment, probably from inhalation of car- 
 bonaceous matter, or a deposit of melanin. 
 
 The pulmonary artery subdivides, and follows the rami- 
 fications of the bronchi to the pulmonary vesicles. Here 
 a multitude of capillary tubes form a network over the 
 alveoli, only separated from the air by the most delicate 
 membrane (Plate XXII, Fig. 168). In the frog we find 
 the whole respiratory portion lined with a continuous 
 layer of flattened epithelia. A similar lining is found in 
 the mammalian foetus, but in the adult the number and 
 character of the epithelial scales is greatly changed. Large 
 non-nucleated plates are seen with occasional traces of the 
 original bioplasm. In inflammatory affections, however, 
 these may multiply, giving rise to catarrhal desquarnation. 
 
 4. Generative Organs. The histology of the organs of 
 reproduction is quite elaborate, and the plan of this work 
 
214 THE MICROSCOPIST. 
 
 only permits us to glance at the essential structures, 
 which are the seminiferous tubules for the secretion of 
 spermatozoa, in the male, and the ovary for the production 
 of the germ, or ovum, in the female. 
 
 The tubuli seminiferi are a multitude of fine and tortuous 
 tubules contained in the testis, with its accessory epididy- 
 mis. They lie in the interstices of sustentacular connec- 
 tive tissue, and consist of membranous tubes filled with 
 cells, which are said to possess amoeboid motion. During 
 the virile period these glandular tubes generate the sper- 
 matozoa, or microscopic seminal filaments. The shape of 
 these spermatozoa is filiform in all animals, but vary in 
 different species. In man they consist of an anterior oval 
 portion, or head, and a posterior flexible filament, or tail. 
 Different observers have taken different views as to the 
 origin of these structures. Some suppose them the product 
 of special cells, others trace them to the nuclei of the 
 glandular epithelium, while others regard them as ciliated 
 elements formed by the metamorphosis of entire cells. 
 Their motions baffle all attempts at explanation, although 
 quite similar to those of ciliated epithelium. The sperma- 
 tozoa penetrate by their movements into the interior of 
 the ovum, in order to impregnate it, and in the mammalia 
 in considerable numbers. 
 
 The ovary may be divided into two portions : a medul- 
 lary substance, which is a non-glandular and very vascular 
 connective tissue, and a glandular parenchyma enveloping 
 the latter. The surface of the ovary uncovered by peri- 
 toneum is coated with a layer of low columnar cells, called 
 the germinal epithelium. Immediately under this is a 
 stratum called the zone of the primordial follicles, or cor- 
 tical zone. Here the young ova lie crowded in layers. 
 They consist of granular bioplasm, containing fatty mol- 
 ecules and a spherical nucleus. They are probably de- 
 veloped by a folding in of the germinal epithelium. To- 
 ward the internal portion of the ovary the follicles become 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 215 
 
 more highly developed, and the ovum contained in them is 
 also increased in size and enveloped in a distinct mem- 
 brane. There are from twelve to twenty mature follicles 
 in the ovariura, named, from their discoverer, Graafian 
 follicles. Each has an epithelial lining, in which the ovum 
 is imbedded. The capsule of the ovum is known as the 
 zona pellucida, or chorion, and the albuminous cell-body is 
 the vitdlus. The nucleus is situated^excentrically, and is 
 called the vesicula germinativa, or germinal vesicle of Pur- 
 kinje. Within it is a round and highly refractive nucle- 
 olus, the macula germinativa, or germinal spot of Wagner. 
 A Graafian vesicle bursts and an ovum is liberated at 
 every menstrual period. During the progress of the latter 
 down the Fallopian tube to the uterus, impregnation may 
 take place by the penetration of spermatozoa into its yelk. 
 Then the inherent vital energies of the cell are aroused, 
 and the process of segmentation begins. TJiiiinpregnated 
 ova are destroyed by solution. The ruptured and emptied 
 Graafian vesicle becomes filled up with cicatricial connec- 
 tive tissue, which constitutes what is called the corpus 
 luteum, after which it gradually disappears. 
 
 II. ORGANS OF ANIMAL LIFE. 
 
 1 . Locomotive. The microscopic structure of bone and 
 muscle has been described in connection with elementary 
 tissues. Tendons and fascias belong to the connective 
 tissues. 
 
 2. Sensory. The nervous apparatus of the body, whose 
 histological elements were treated of on a previous page, 
 has been classified physiologically into: 
 
 1. The sympathetic system, consisting of a chain of gan- 
 glia on each side of the vertebral column, with commu- 
 nicating cords or extensions of ganglia, visceral nerves, 
 arterial nerves, and nerves of communication with the 
 cerebral and spinal nerves. The chief structural differ- 
 
21(3 THE MIGROSCOPIST. 
 
 ence between this and the cerebro-spinal system is that in 
 the latter the nerve-cells form large masses, and the union 
 of its parts is effected by means of central fibres, while in 
 the sympathetic the cells are more widely separated, and 
 union between them and with the cerebro-spinal axis is 
 by means of peripheral fibres. The sympathetic is con- 
 sidered a motor and sensitive nerve to internal viscera, 
 and to govern the actions of bloodvessels and glands. 
 
 2. The cerebro-spinal system, divided into : 
 
 (1.) A system of ganglia subservient -to reflex actions, 
 the most important of which is the spinal cord, where the 
 gray or vesicular nervous matter forms a continuous tract 
 internally. 
 
 (2.) A ganglionic centre for respiration, mastication, 
 deglutition, etc., with a series of ganglia in connection 
 with the organs of special sense: the medulla oblongata, 
 with its neighboring structures; the mesocephalon, cor- 
 pora striata, and optic thalami. 
 
 (3.) The cerebellum, a sort of offshoot from the upper 
 extremity of the medulla, for adjusting and combining 
 voluntary motions. 
 
 (4.) The cerebrum, cerebral hemispheres, or ganglia, 
 which are regarded as the principal organs of voluntary 
 movements. In the lower vertebrates the hemispheres 
 are comparatively small, so as not to overlap the other 
 divisions of the brain ; but in the higher Mammalia they 
 extend over the olfactory lobes and backward over the 
 optic lobes and cerebellum, so as to cover these parts, 
 while they also extend downward toward the base of the 
 brain. In the lower vertebrates, also, the surface of the 
 hemispheres is smooth, while in the higher it is compli- 
 cated by ridges and furrows. 
 
 (5.) The cerebral and spinal nerves. The spinal nerves 
 arise in pairs, generally corresponding with the vertebrae. 
 Each has two roots, one from the dorsal, and one from 
 the ventral region of its half of the cord. The former 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 217 
 
 root has a ganglionic enlargement, and contains only sen- 
 sory fibres ; the latter has no ganglion, and contains only 
 motor fibres. 
 
 The cerebral nerves are those given off from the base 
 of the brain. Some of these minister to special sensation, 
 as the olfactory, optic, auditory, part of the glosso-pha- 
 ryngeal, and the lingual branch of the trifacial nerves. 
 Some are nerves of motion, as the motor oculi, patheti- 
 cus, part of the third branch of the fifth pair, the abdu- 
 cens, the facial and the hypoglossal nerves. Others are 
 nerves of common sensation, as the fifth, and part of the 
 glosso-pharyngeal nerves. Others, again, are mixed, as 
 the pneumogastric and spinal accessory nerves. 
 
 The minute structure of the central organs of the ner- 
 vous system is excessively complicate and full of details. 
 Hardening with chromic acid and bichromate of potash 
 is generally advisable before examination. This should 
 be done with small pieces in a large quantity of the fluid. 
 One-eighth to one-half grain of bichromate, or 0.033 to 
 0.1 grain of chromic acid, to the ounce of water should 
 be used; the strength gradually increased from day to 
 day. After such maceration for several days, a drop of a 
 28 per cent, solution of caustic potash may be added to 
 one ounce of water, and the specimen soaked in it for an 
 hour, to macerate the connective tissue. After again soak- 
 ing in graduated solutions of the bichromate, up to two 
 grains to the ounce, the tissue may be carefully picked 
 apart under the dissecting microscope. In such manner 
 Deiters discovered the two kinds of processes in the multi- 
 polar ganglion-cells. Gerlach placed thin sections for two 
 or three days in 0.01 to 0.02 per cent, solutions of bichro- 
 mate of ammonia, and picked them apart after staining 
 with carmine. 
 
 Lockhart Clarke placed parts of the spinal cord in equal 
 parts of alcohol and water for a day, then for several days 
 in pure alcohol, till thin sections could be made. These 
 
218 THE MICROSCOPIST. 
 
 were immersed for an hour or two in a mixture of one part 
 acetic acid and three parts alcohol, to render the gray 
 matter transparent and the fibrous elements prominent. 
 
 Sections may be stained with carmine and mounted in 
 glycerin or balsam (see Chapter Y). 
 
 (6.) Organs of special sense: 
 
 a. Organs of Touch. The tactile papillae of the skin 
 and Pacinian corpuscles may be studied in thin sections 
 of fresh or dried skin. Treatment with dilute acetic 
 acid, or acetic acid and alcohol, and staining with car- 
 mine, or chloride of gold, is recommended. The papillae 
 are made up of connective tissue, into which nervous fila- 
 ments enter, and end in peculiar tactile corpuscles (Plate 
 XXIII, Fig. 173). The structure of the skin itself, with 
 its various layers and sudoriparous glands, may be seen 
 in such sections. 
 
 b. Organs of Taste. The terminations of the gustatory 
 nerves of the tongue are yet imperfectly known. In the 
 circumvallate papillae, on the side walls, certain structures 
 are found, called gustatory buds or taste-cups (Plate XXIII, 
 Fig. 174). They consist of flattened lanceolate-cells, ar- 
 ranged like the leaves of a flower-bud, and containing 
 within them fusiform gustatory cells, which end in rods, 
 and filaments projecting from the rods above the buds 
 are seen in some animals. Underneath is a plexus of pale 
 and medullated nerve-fibres. The mode of nervous ter- 
 mination in the fungiform papillae is not known. For pri- 
 mary examination, sections of the dried tongue may . be 
 softened in dilute acetic acid and glycerin, or hardened in 
 osmic acid. For the finer structure, maceration in iodine 
 serum, and immersion in one-half per cent, chromic acid, 
 with an equal quantity of glycerin, is recommended. 
 Careful picking under the simple microscope is necessary. 
 Sections may also be stained with chloride of gold. 
 
 c. Organs of Smell. In the olfactory regions, which are 
 patches of yellowish or brownish color on the upper and 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 219 
 
 deeper part of the nasal cavity, we find nucleated cylin- 
 drical cells taking the place of ordinary ciliated epithe- 
 lium, and sending processes downward, which communi- 
 cate with each other, forming a delicate network (Plate 
 XXI V, Fig. 175). Between these cells we find the olfac- 
 tory cells, spindle-shaped nucleated bodies, extending up- 
 ward into a fine rod and downward into a varicose fila- 
 ment. In birds and amphibia these rods are terminated 
 by delicate hairs, some of which have ciliary motion. 
 Beneath these structures are peculiar glands, consisting 
 of pigmeuted gland-cells. They are called Bowman's 
 glands. The branches of the olfactory nerve proceed be- 
 tween these glands and branch out into fine varicose fila- 
 ments, which are supposed to communicate with the 
 olfactory cells. Hardening in chromic acid, or Muller's 
 fluid, or a concentrated solution of oxalic acid, or one- 
 half to one per cent, solution of sulphuric acid, is neces- 
 sary for the preservation of these delicate structures. 
 
 d. Organs of Sight. As in the sense of touch certain 
 tactile papillae detect deviations from the general surface ; 
 and in that of taste special rod-like end organs and their 
 covering bulbs distinguish the solutions of different sapid 
 substances ; and as in smelling, not the whole organ but 
 olfactory regions, with peculiar cells and nervous rods, 
 discriminate mechanical or chemical odors, so in vision a 
 special apparatus is provided to perceive the wonderful 
 variety of colors and forms. The minute structure of 
 organs becomes more complex in proportion as they serve 
 the higher functions of mind. 
 
 The various tunics and accessory structures of the eye 
 are described in most text-books ; we here limit ourselves 
 to a brief reference to those refracting and receptive struc- 
 tures w^hose office it is to translate the phenomena of light 
 into those of nervous conduction. 
 
 Externally, we have in front of the eye the transparent 
 cornea. This is made of connective tissue with cells, bun- 
 
220 THE MICROSCOPIST. 
 
 dies of fibres, and cavities containing cells. Its tissues are 
 in layers, as follows : 1. External epithelium, flat and 
 laminated. 2. Anterior basement-membrane or lamina. 
 3. True corneal tissue. 4. Membrane of Descemet or 
 Demours. 5. Endotbeliurn with flat cells (Plate XXIY, 
 Fig. 176). The cells of corneal tissue are of two forms. 
 The first are wandering or amoeboid cells, and may be 
 seen in a freshly extirpated frog's cornea placed underside 
 up, with aqueous humor in a moist chamber, on the stage 
 of the microscope. If a small incision be made at the 
 margin of the cornea of a living frog a few hours before 
 its extraction, and vermilion, carmine, or anilin blue is 
 rubbed in, the cells which have absorbed the coloring 
 matter will be found at some distance afterwards, having 
 wandered like leucocytes or pus-cells elsewhere. Their 
 origin may be from blood or true corneal corpuscles, or 
 both. The second form, or corneal corpuscles, are im- 
 movable, flat, with branching or stellate processes. They 
 may be demonstrated by staining with chloride of gold 
 or nitrate of silver. The bundles of fibrillar substance in 
 the cornea pass in various directions, and the natural 
 cavities in it contain the corneal cells. As stated, the 
 nerves of the cornea have been traced to the external 
 epithelium, which sometimes contains serrated (rift' or 
 stachell) cells. 
 
 The aqueous humor is structureless, but the vitreous 
 humor is supposed to have delicate membranous septa. 
 The crystalline lens consists of a capsule inclosing a tissue 
 of fine transparent fibres or tubules, which are of epithe- 
 lial origin. These fibres are flat, and often have serrated 
 borders, especially in fishes. 
 
 The retina, or nervous portion of the eye, is the most 
 important, as its delicacy and liability to decomposition 
 render it the most difficult object of microscopic exami- 
 nation. 
 
 We must dismiss the popular notion of minute images 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 221 
 
 produced on the retina by the lens to be viewed by the 
 mind. The lens does, indeed, form an image on the mem- 
 brane, so it would on glass or paper, but the real action 
 of the vibrations of light upon the nervous conductors is 
 not thus to be explained. 
 
 The complex structure of the retina is only recently 
 known, and it may be that many laws of light yet un- 
 known are to be exhibited by its means, as well as much 
 that relates to the connection of the perceiving thinking 
 mind and the external world. 
 
 Muller's fluid, concentrated solution of oxalic acid, 0.6 
 per cent, solution of sulphuric acid, and 0.1 to 2 per cent, 
 solutions of osmic acid, may be used for hardening, but 
 very delicate dissection is required for demonstration. 
 Rutherford recommends chromic acid and spirit solution, 
 1 gramme of chromic acid in 20 c.c. of water, and 180 c.c. 
 of methylated spirit added slowly. 
 
 The retina consists of the following layers : 1. The 
 columnar layer, or layer of rods and cones. 2. Membraua 
 limitans externa. 3. External granular layer. 4. Inter- 
 granular layer. 5. Internal granular layer. 6. Molecular 
 layer. 7. Ganglionic cell layer. 8. Expansion of optic 
 nerve. 9. Membrana limitans interim. To these may be 
 added : 10. The pigment layer, often described as the 
 pigmented epithelium of the choroid, into which the rods 
 and cones project. These layers are composed of two 
 different elements, mutually blended, a connective-tissue 
 framework of varying structure in the different layers, 
 and a complex nervous tissue of fibres, ganglia, rods, and 
 cones. Plate XXIY, Fig. 177, is a diagram of these 
 separate structures, after M. Shultze, in Strieker's Man- 
 ual of Histology. 
 
 The structure of the rods and cones is complex, and 
 varies in different animals. The rods readily decompose, 
 becoming bent and separated into disks, but examination 
 of well-preserved specimens shows them to have a fibril- 
 
222 THE MICROSCOPIST. 
 
 lated outer covering. In addition, certain globular or 
 lenticular refractive bodies, of different shape and color 
 in different animals, are found in these structures (Plate 
 XXIV, Fig. 178), which doubtless are designed to give 
 the rays of light such a direction for final elaboration in 
 the outer segment as they could not receive from the 
 coarser refractive apparatus in the front of the eye. 
 
 e. Organs of Hearing. These are most intimately con- 
 nected with mental functions, because of language, which 
 is the highest sensual expression of mind. Hence the 
 structure of these organs is most delicate and complex. 
 
 The labyrinth is the essential part of the organ, con- 
 sisting in man of the vestibule, the semicircular canals, 
 and the cochlea. Sonorous undulations are propagated 
 to the fluid in the labyrinth through the tympanum and 
 chain of otic bones. 
 
 The auditory nerves are distributed to the ampullae and 
 sacculi of the vestibule, and to the spiral plate of the 
 cochlea. At the terminal filaments in the sac of the 
 vestibule, crystals, called otoliths, of shapes -differing in 
 various animals, are inclosed in membrane. Hasse con- 
 siders them to be vibrating organs, but Waldeyer regards 
 their function to be that of dampening sound. 
 
 As we distinguish in sounds the various qualities of 
 pitch, intensity, quality, and direction, it is probable that 
 there is a special apparatus for each, but histology has 
 not yet established this fully. Kolliker thinks the gan- 
 glionic termination of the cochlear nerve renders it proba- 
 ble that it only receives sonorous undulations. The ex- 
 periments of Floureris seem to show that the semicircular 
 canals influence the impression of direction of sound. 
 
 In the sacs of the vestibule and ampullne, the ner^e- 
 fibres are confined to a projection of the walls called the 
 septum nerveum. Here are found cylinder- and fibre-cells, 
 with rods, basal-cells, and nerves. But it is in the lamina 
 spiralis of the cochlea that the most elaborate organ, 
 
PLATE XXIV. 
 
 FIG. 175. 
 
 FIG. 176. 
 
 Olfactory cells. 
 
 Section of Cornea. 
 
 FIG. 177. 
 
 FIG. 179. 
 
 
 Connective-tissue and nerve-elements of Retina. 
 Showing rods and cones. 
 
 Refractive bodies in the rods and cones. 
 
 Section of Cochlea: v, scala vestibuli; T, scala 
 tympani; c, canal of Cochlea; R, Reissner's mem- 
 brane, attached at a to the habenula sulcata; b, 
 connective-tissue layer ; c, organ of Corti. 
 
 FJG. 180. 
 
 Corti's organ, from above. 
 
 FIG. 181. 
 
 Section of Corti's organ. 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 223 
 
 called from its discoverer the organ of Corti, is found. 
 Kolliker considers the free position of the expanded por- 
 tion of the nerve, and the extent of surface over which 
 its terminal fibres are spread, to constitute it an organ of 
 great delicacy, enabling us to distinguish several sounds 
 at once and to determine their pitch. There is a striking 
 analogy between the visual and auditor} 7 apparatus in the 
 gauglionic structure of the nerve-structure. Plate XXIY, 
 Fig. 179, represents a vertical section through the tube 
 of the cochlea; and Plate XXIY, Figs. 180 and 181, the 
 vestibular aspect and a vertical section of Corti's organ. 
 
 Waldeyer recommends examination of the cochlea in a 
 fresh state and in aqueous humor. Preparations in osmic 
 acid and chloride of gold are also useful. For sections he 
 removes much of the bony substance of large cochleae with 
 cutting pliers, opens the membrane in several places, and 
 places the specimen in 0.001 per cent, of chloride of palla- 
 dium, or 0.2 to 1 per cent, osmic acid solution for twenty- 
 four hours, then for the same time in absolute alcohol. 
 It is then treated with a fluid composed of 0.001 per cent, 
 chloride of palladium with one-tenth part of J to 1 per 
 cent, muriatic or chromic acid, to deprive it of earthy 
 salts. It is then washed in absolute alcohol, and inclosed 
 in a piece of marrow or liver, and placed to harden in 
 alcohol again. The hollows of the cochlea may be filled 
 with equal parts of gelatin and glycerin before they are 
 inclosed. Sections must be cut with a sharp knife. 
 
 Rutherford advises the softening of the bone and hard- 
 ening of other tissues by maceration in chromic acid and 
 spirit (1 gramme of chromic acid in 20 c.c. of water, and 
 180 c.c. of methylated spirit slowly added). For sections 
 he commends Strieker's mode of imbedding in gum. Place 
 the cochlea in a small cone of bibulous paper, containing 
 a strong solution of gum arabic, for four or five hours ; 
 then immerse the cone in methylated spirit for forty-eight 
 
224 THE MICROSCOPIST. 
 
 hours, or until the gum is hard enough. The sections 
 may be stained with carmine, logwood, silver, or gold. 
 
 The following suggestions from Rutherford's Outlines 
 of Practical Histology, will be of service to the student in 
 this department : 
 
 Most of the tissues required may be obtained from the 
 cat or guinea-pig. Feed the cat, and an hour or so after 
 place it in a bag; drop chloroform over its nose until it is 
 insensible. Open the chest by a linear incision through 
 the sternum, and allow the animal to bleed to death from 
 a cut in the right ventricle. 
 
 Divide the trachea below the cricoid cartilage and in- 
 ject it with J per cent, chromic acid fluid ; tie it to prevent 
 the escape of fluid, and place the distended lungs in the 
 same fluid, and cover them with cotton-wool. Change 
 the fluid at the end of eighteen hours. Allow them to 
 remain in this fluid for a month, then transfer to methy- 
 lated spirit till needed for mounting. 
 
 Open by a linear incision the oesophagus, stomach, large 
 and small intestines, and wash them with salt solution (} 
 per cent.). Place a portion of small intestine in chromic 
 and bichromate fluid (1 gramme chromic acid and 2 
 grammes potassium bichromate in 1200 c.c. water) for two 
 weeks (change the fluid at the end of eighteen hours), and 
 then in methylated spirit till required. Act similarly 
 with parts of oesophagus, stomach and large intestine, in 
 J per cent, chromic acid for three or four weeks. A por- 
 tion of stomach may be placed in Muller's fluid till re- 
 quired for preparation of non-striped muscle, and of the 
 gastric follicles. 
 
 The bladder may be treated as the small intestine. 
 
 Divide one kidney longitudinally, and the other trans- 
 versely, and place in Muller's fluid. Change the fluid in 
 eighteen hours, and after four weeks transfer to methy- 
 lated spirits. They will be ready for use in two weeks 
 after. 
 
THE MICROSCOPE IN ANIMAL HISTOLOGY. 225 
 
 Cut one-half of the liver into small pieces and prepare 
 as the kidneys. The tongue, divided transversely into five 
 or six pieces, the spleen, uterus, and thin muscles from 
 limbs or abdomen, in J per cent, chromic acid. Change as 
 before, and in a month to methylated spirit. 
 
 Testis of dog, freely incised, and ovaries of cat or dog, 
 in Muller'ja fluid, and after three weeks to methylated 
 spirits. 
 
 Divide the eyes transversely behind the lens. Remove 
 the vitreous. Place posterior halves in chromic and spirit 
 solution. Change in eighteen hours. Transfer to methy- 
 lated spirit in ten days. Place the lens in Miiller's fluid 
 for five weeks, and then in methylated spirits. The cor- 
 nea may remain in J per cent, chromic acid for a month, 
 and then in methylated spirit. 
 
 Cautiously open the cranial and spinal cavities. Re- 
 move brain and cord, and strip oft' arachnoid. Partially 
 divide the cord into pieces a half inch long. Partially 
 divide the brain transversely into a. number of pieces. 
 Place in a cool place in methylated spirits for eighteen 
 hours. Transfer cord to J per cent, chromic acid for six 
 or seven weeks. Change in eighteen hours. Prepare the 
 sciatic nerve in the same manner. Place the brain in 
 chromic and bichromate fluid. Change in eighteen hours, 
 and then once a week, until the brain is hard. If not 
 leathery in six weeks place in J per cent, chromic acid for 
 two weeks, and then in methylated spirits. Support the 
 brain and cord on cotton-wool in the hardening fluid. 
 
 Remove muscles, but not periosteum from bones of 
 limbs, and both from the lower jaw. Divide the bones 
 transversely in two or three places, and put them in chro- 
 mic and nitric fluid (chromic acid, 1 gram ; water, 200 
 cc. ; then add 2 cc. nitric acic]). Change the fluid often 
 until the bone is soft enough, and transfer to methylated 
 spirits. If not complete in a month, double the quantity 
 of nitric acid in the fluid. 
 
 15 
 
226 THE MICROSCOPIST. 
 
 Place a piece of human scalp, skin from palmar surface 
 of finger, and skin of dog (for muscles of hair-follicles) in 
 chromic and spirit fluid. In a month transfer to methy- 
 lated spirit. 
 
 Remove the petrous portion of temporal bone, open the 
 tympanum, pull the stapes from the oval fenestra, and 
 place the cochlea in chromic and spirit fluid. Change in 
 eighteen hours, and at the end of seven days, if a brown 
 precipitate falls, change fluid every third day. On the 
 tenth or twelfth day transfer to chromic and nitric fluid. 
 Change frequently till the bone is soft. Then place it in 
 methylated spirit. The cochlea of the guinea pig pro- 
 jects into the tympanum, and is, therefore, convenient for 
 enabling the student to see how the cone is to be sliced 
 when sections are made. 
 
 Too long exposure to chromic acid renders tissues fria- 
 ble, and prevents staining with carmine. 
 
 Methylated spirit is ordinary alcohol containing 10 per 
 cent, of wood-naphtha, and is used in England as a sub- 
 stitute for alcohol, since it is free of duty for manufactur- 
 ing purposes. 
 
 CHAPTER XIII. 
 
 THE MICROSCOPE IN PATHOLOGY. 
 
 PATHOLOGICAL histology treats of the minute anatomy 
 of the tissues and organs in disease, and is essential to a 
 knowledge of structural changes in the body. Since the 
 old method of judging solely by symptoms has given place 
 to the more rational observation of the actual changes 
 produced, the microscope has become an indispensable aid 
 to practical medicine. As anatomy would be coarse and 
 imperfect without histology, so pathological histology 
 
THE MICROSCOPE IN PATHOLOGY. 227 
 
 perfects pathology, and guides to right conclusions the 
 seeker after positive truth in medicine. 
 
 Our plan forbids an extensive outline of the facts of 
 morbid anatomy. We propose merely such a classifica- 
 tion of the microscopic appearances of diseased structures 
 as may serve to guide the student and busy practitioner 
 in actual observation. 
 
 PREPARATION OF SPECIMENS. 
 
 Much may be learned by the examination of a patho- 
 logical specimen without any preparation whatever, or 
 with the use of indifferent fluids (see Chapter Y). A thin 
 section may be made under water with a Valentin's knife, 
 or a small portion may be snipped off with curved scis- 
 sors and teased with fine needles. The freshly-cut sur- 
 face of tumors may be gently scraped with a knife and 
 the separated elements examined in glycerin and water. 
 
 For a thorough examination it will be necesSary to 
 harden, stain, and make thin sections, as described in 
 Chapter V and at page 224. Miiller's fluid, page 68, will 
 be found most generally useful for morbid specimens. 
 After small pieces have lain some time in this they can be 
 still further hardened by absolute alcohol. Before cut- 
 ting thin sections, either by hand or with a section-cutter, 
 the specimen will require to be imbedded so as to be 
 readily held and cut without tearing. A mixture of wax 
 or paraffin and olive oil is generally used of such consist- 
 ence as will indent readily with the thumb-nail when 
 cold. For very delicate tissues, saturation in a mixture 
 of glycerin and gum arabic, made perfectly clear and vis- 
 cid, so as to be easily drawn out into threads, is useful. 
 After saturation the specimen is thrown into alcohol, 
 which hardens the gum and fixes the tissues so as to be 
 readily cut. The thin section can be thrown into water, 
 or carmine solution, to dissolve the gum, and the stained 
 
228 THE MICROSCOPIST. 
 
 preparation can be mounted in glycerin, balsam, or dam- 
 mar (Chapter YI). In fixing the cover to specimens 
 mounted in glycerin it may be useful to apply liquid glue 
 or strong gelatin solution to the edges, using the turn- 
 table or otherwise, and after it is dry to cover it with 
 some other cement. Any glycerin which may accident- 
 ally be on the cover had better be left until the glue has 
 dried, when it can be removed by a camel's hair brush and 
 water. 
 
 Dr. Beale recommends that nitrate of silver, chloride 
 of gold, osmic acid, etc., when used for staining fine tis- 
 sues, should be dissolved in glycerin. Less than J per 
 cent, solution of gold, etc , will thus bring out details 
 which are scarcely attained otherwise. The time of soak- 
 ing and strength of the solution varies according to the 
 tissue and effect desired. 
 
 The most delicate sections are made by freezing speci- 
 mens after they have been well saturated with a strong 
 solution of gum arabic. For this purpose Professor 
 Rutherford's freezing microtome has been invented, in 
 which the cylinder of the ordinary section-cutter, page 
 63, is surrounded by a reservoir for powdered ice and salt, 
 so as to freeze the tissue. Dr. Beale recommends freez- 
 ing by the use of nitrous oxide gas, and Dr. Pritchard 
 has suggested a metallic cylinder with a wooden handle, 
 which can be cooled below the freezing-point by salt and 
 ice. A small piece of tissue will immediately freeze on 
 the metal so as to be cut into thin sections by hand. If 
 thawing sets in it may be covered with thin gutta-percha 
 and plunged into the ice and salt. 
 
 Dr. S. Marsh, in an excellent little treatise on section- 
 cutting, recommends that the knife should not be ground 
 flat on one side, but be slightly concave on each side. In 
 cutting it is necessary to keep the blade well flooded with 
 spirit, except in using the freezing microtome. The sec- 
 tions are best transferred to a basin of water, and lifted 
 
THE MICROSCOPE IN PATHOLOGY. 229 
 
 to the staining fluid, etc., not with a camel's hair brush, 
 but with a little slip of tin, copper, etc., with a bent and 
 perforated end, making a sort of lifter or flat spoon. In 
 making sections, either by hand pr with the section-cut- 
 ter, the razor or knife must be kept always sharp, and 
 drawn from heel to point so as to cut with a single stroke 
 the thinnest possible slice. 
 
 THE APPEARANCE OF TISSUES AFTER DEATH. 
 
 Formation and decomposition, or progression and retro- 
 gression, coexist in most morbid structures, so that it is 
 necessary for the student not only to be familiar with 
 normal histology, but also with the products of decay and 
 death and the varied appearances in disease. 
 
 The death of the individual parts of the organism is 
 called necrosi*, mortification, or gangrene. Various changes 
 follow it, depending chiefly on moisture, producing dry or 
 moist gangrene. 
 
 Xecrosis depends on the cessation of the nutritive pro 
 cess from abolition of the normal supply of blood, or from 
 mechanical or chemical violence. 
 
 Living tissues bathed in suitable fluids dissolve albumi- 
 nates and their derivatives, but when life departs they no 
 longer withstand solution themselves. 
 
 1. Protoplasm. It has been shown, page 118, that the 
 term bioplasm has been appropriated to elementary or 
 germinal structure during life, and at page 188 we re- 
 garded the leucocytes, or white corpuscles of the blood, 
 chyle, etc., as simply bioplasts. After death, or in order 
 to designate their physical constitution, the most suitable 
 term for them is protoplasm. In necrosis this colorless 
 protoplasm dissolves after slightly swelling, and entirely 
 disappears. 
 
 2. Blood. Decomposes very rapidly. The coloring 
 matter leaves the red corpuscles and is diffused through 
 
230 
 
 THE MICROSCOPIST. 
 
 FIG. 182. 
 
 the tissues (hence the dark color of a scab), then the cor- 
 puscle disintegrates and breaks up into granules. Some- 
 times there is found an aggregation of brownish-colored 
 blood-corpuscles undergoing disintegration at the edges as 
 in Fig. 1 82. 
 
 3. Nucleated Cells. In these the 
 protoplasm coagulates, forming a 
 solid albuminate, which becomes 
 cloudy and breaks up into gran- 
 ules. 
 
 4. Cell membrane resists de- 
 composition in proportion as it 
 has become horny. Hence the 
 outer layers of epithelium last 
 longer than the inner ones. 
 
 The gangrenous disintegration of 5 ' Smooth MliSCldar ^ Fibre. 
 tissues, a. Aggregation of blood-cor- Minute dusty granulations first 
 puscles. 6. Smooth muscular fibres. . , . , 
 
 c. striated muscular fibres. <z. Break- make their appearance, which 
 
 ing up of same into Bowman's disks. un ite SO that the fibre SeeHlS 
 1-300. After RINDFLEISCH. . 
 
 transversely striated. As decay 
 
 goes on the muscle changes into a slimy granular substance 
 which may be drawn into threads. 
 
 6. Striated Muscular Fibre. The muscle-juice coagu- 
 lates to a solid albuminate, giving rise to rigor mortis in 
 from twelve to fourteen hours after death, except in death 
 from charcoal or sulphuretted hydrogen vapor, lightning, 
 or from putrid fevers, or long debility. This stiffness of 
 muscle lasts about twenty-four hours. In the necrosed 
 fibres under the microscope the transverse striae and nu- 
 clei disappear amid a cloud of minute granulations, then 
 fat-globules and reddish pigment-granules show them- 
 selves, the fibres melt away from the edges and become 
 gelatinous. If gelatinous softening is marked the fibres 
 may disintegrate into Bowman's disks, or disks produced 
 by transverse cleavage (Fig. 182). 
 
 7. Nerve-tissue. Little is known of the process of de- 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 231 
 
 FIG. 183. 
 
 cay in nerves save that the thicker nerve-trunks maintain 
 themselves for a comparatively long time, while the finer 
 ramifications soon dissolve. The white substance of 
 Schwanu (page 199) first coagulates, then there is a col- 
 lection of drops of myelin within the neurilemma, produc- 
 ing varicosity before complete dissolution. 
 
 8. Adipose Tissue. The fluid fat leaves the cells and 
 gives an appearance of emulsion to the mass. Crystals of 
 margarin, etc., sometimes appear on the cell-walls. 
 
 9. Loose connective tissue fibres swell, become stained 
 with the coloring matter of blood, granulate, and liquefy ; 
 or they may desiccate by evaporation. 
 
 10. Elastic fibres and fi- 
 brous networks resist longer 
 than the last. Hence, elastic 
 fibres may be found in expec- 
 torated matter from gangre- 
 nous lungs, etc. Later they 
 break into granular stride, then 
 into molecules and vanish. 
 
 11. Cartilage lasts long, but 
 melts away at the edges, first 
 becoming transparent and red- 
 dish. The cells fill with fat- 
 globules from fatty degenera- 
 tion of the bioplasm. 
 
 12. Bone retains its struc- 
 ture long, so as to be recog- 
 nized by the surgeon in seques- 
 tra, yet it decays in patches. 
 The bioplasm changes to fat 
 in the cells, acid tiuids dissolve 
 
 the lime salts, and the remaining structure disintegrates 
 like cartilage. 
 
 The chemical products of decomposition are but par- 
 tially known. Some are volatile, some soluble in water, 
 
 Products of gangrenous disintegra- 
 tion, a. Leucin ; b. Tyrosin ; c. Fat- 
 crystals ; d. Ammoniaco-magnesian 
 phosphate ; e. Gangrene particles (blacs 
 pigment);/. Vibriones. 1-300, After 
 
 KlXDFLEISCH. 
 
232 THE MICROSCOPIST. 
 
 and others more solid, producing a new series of micro- 
 scopic objects after the disappearance of the histological 
 forms (Fig. 183). 
 
 Leucin (Fig. 183, a] forms partly homogeneous drops 
 or globules, partly bodies of concentric layers, and partly 
 stellate spheres of minute crystalline needles. 
 
 Tyrosin (b) generally found along with leucin, forms 
 satiny white needles, isolated, or in sheafs or rosettes. 
 
 iMargarin (c) a mixture and crystalline separation of 
 the solid fats, stearin, and palmitin, occurs quite fre- 
 quently. 
 
 Ammoniaco-magnesian phosphate (d) is only found in 
 alkaline or neutral ichor. 
 
 Pigment-bodies (e) are very small, and have a variety of 
 forms. As characteristic of necrosis the small, black, 
 irregular particles, resisting most reagents, must be dis- 
 tinguished from hsematin pigments, though they are 
 probably identical with melalin. 
 
 Living Organisms (/). In addition to minute fungi, or 
 moulds (aspergillus, oidium, etc.), vibriones are quite com- 
 mon. Pasteur regards them as the visible elements of 
 decay (see page 135). 
 
 DEGENERATION OF TISSUES. 
 
 Degenerations are usually divided into two classes, true 
 degenerations, or metamorphoses, and the infiltrations. 
 
 1. The true degenerations or metamorphoses are char- 
 acterized by the direct change of the albuminoid constitu- 
 ents of the tissues into new material. The metamor- 
 phoses include fatty, mucoid, and colloid degenerations. 
 
 2. The infiltrations differ from the true degenerations, 
 since the new material which exists in the tissues is not 
 derived from their albuminoid constituents, but is de- 
 posited in them from the blood. The anatomical char- 
 acters are much less altered than in the metamorphoses, 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 233 
 
 FIG. 184. 
 
 . 
 
 and function is usually less interfered with. They include 
 fatty, amyloid, calcareous, and pigmentary infiltration, etc. 
 
 THE METAMORPHOSES. 
 
 1. Fatty Degeneration. 
 
 The metamorphosis of the protoplasm of the cell is 
 marked by the occurrence of fat- 
 globules in its interior. Its pro- 
 gress may be illustrated by de- 
 generating epitheliun in dropsy 
 of the pericardium (Fig. 184). 
 
 The granular corpuscles were 
 formerly known as the " inflam- 
 matory " or u exudation corpus- 
 cles," or " corpuscles of Gluge." 
 They are identical in structure 
 with colostrum-corpuscles thrown 
 off by the mammary gland after 
 parturition, and the last act of 
 fatty degeneration is considered 
 
 as a fortification. The fatty detritus may be absorbed as 
 milk, or if not absorbed it is partly saponified and partly 
 separated in solid form, as margarin, etc. Finally there is 
 an abundant deposition of crystals of cholesterin (Fig. 185). 
 
 This substance is found nor- 
 mally in the brain and spinal 
 marrow in quite large propor- 
 tions, and in solution in the 
 bile. It forms rhombic tablets, 
 lying in heaps, with their long 
 sides parallel. 
 
 In some cases when the fatty 
 detritus is not absorbed it 
 undergoes a change into a 
 crumbling material somewhat 
 resembling cheese, and hence called caseation. This ap- 
 
 The fatty metamorphosis. Epi- 
 thelium of the pericardium in 
 dropsy of pericardium, a. Cells 
 which still show the normal form 
 and arrangement. First appear- 
 ance of fat-globules, b. Granular 
 globules, the one with a nucleus 
 still visible, c. Granular globules 
 disintegrating to fatty detritus. 
 After RIMJFLEISCH. 
 
 FIG. 18o. 
 
 Crystals of cholesterin. After VIB- 
 CHOW. 
 
234 
 
 THE MICROSCOPIST. 
 
 pears to be owing to desiccation of the substance from de- 
 ficient vascular supply. It is most frequent in parts which 
 contain but few vessels, or in those in which the vessels 
 are obliterated by new growths. It was formerly believed 
 to be the product of tuberculosis, and regarded as the 
 separation of morbid matter (crude tubercle) from dis- 
 eased blood. Tubercle may undergo fatty degeneration 
 and caseation, but it is by no means true that all cheesy 
 masses are tubercular. 
 
 Fatty degeneration in the arteries may be illustrated 
 by atheroma, beginning as a fatty metamorphosis of con- 
 nective tissue, and ending in calcification or impregnation 
 with lime salts. In the fibres of voluntary muscle the al- 
 buminous matter of the fibre is converted into fat, which 
 is seen in rows of minute globules, like strings of pearls 
 in the long axis of the primitive bundles, while the trans- 
 verse striae become indistinct (Fig. 186). 
 
 In advanced stages of infantile spinal 
 paralysis, perhaps from inaction as well 
 as innutrition, the atrophied muscles are 
 subject to fatty degeneration, which may 
 be observed by removing small portions 
 of muscular tissue by Duchenne's trocar, 
 a sort of double needle, one part of which 
 slides upon the other, jutting against a 
 steel shoulder, so as to catch and detach 
 a small piece from a muscle into which it 
 is inserted. A microscopic examination 
 of the detached fibre will show the 
 amount of degeneration, and thus from 
 time to time the progress of disease or 
 the effects of treatment may be noted. 
 
 In pulmonary emphysema the epithe- 
 lium is so changed by fatty degeneration 
 that the degenerated elements are better 
 
 FIG. 186. 
 
 Fatty degeneration 
 of striated muscular 
 fibres. 1-300. After 
 
 ElNDFLEISCH. 
 
 seen than the normal (Fig. 187). 
 
TOE MICROSCOPE IN PATHOLOGY. 
 
 235 
 
 Softening of the brain, as it is termed, is largely clue to 
 fatty degeneration. Whatever interferes with nutrition, 
 by preventing a proper supply of blood, will produce fatty 
 degeneration and softening. Acute cases may be pro- 
 duced by embolism or thrombosis. White softening is 
 generally a chronic condition of old age, and owes its 
 
 FIG. 187. 
 
 From the inner surface of a larger emphysema vesicle. Fatty remains of the lung- 
 tissue, containing elastic fibres, smooth muscular fibres, and covered with fatty degen- 
 erated epithelia. 1-500. After RIXDFLEISCH. 
 
 color to the gradual diminution of blood-supply. Yellow 
 and red softening depend on larger proportions of blood- 
 pigments. A vertical section of a specimen of yellow 
 softening shows accumulations of fatty granules between 
 the nerve-fibres, and their formation into larger granular 
 corpuscles (Fig. 188). 
 
 2. Hucoid Degeneration. 
 
 This is a transformation of albuminoid tissues into 
 mucin, a material of a soft jelly like consistence. This is 
 
236 
 
 THE MICROSCOPIST. 
 
 the embryonic condition of most tissues, and in the um- 
 bilicus and the vitreous humor of the eye this character 
 persists after birth. 
 
 The mucus which normally covers the mucous mem- 
 branes is largely, if not wholly, derived from the swell- 
 ing and softening of epithelial cells, but in mucoid degen- 
 
 A 
 
 Yellow softening of the white substance of the brain. A. Border of the depot of soft- 
 ening, B, and of the brain-substance, C, not yet softened. D. A fatty degenerated ves- 
 sel. 1-300. After RINDFLEISCH. 
 
 eration the change chiefly pertains to the intercellular 
 elements. Thus cartilage softens (Fig. 189). 
 
 The matrix first exhibits striae which afterwards split 
 into fibres. The ends of the fibrils taper to a point and 
 are dissolved by mucoid metamorphosis. In bone the 
 solution of the lime salts and the liquefaction of the basis- 
 substance are generally simultaneous, but in some cases, 
 as in Fig. 190, the difference between the two is quite 
 apparent. 
 
 3. Colloid Degeneration. 
 
 In this the cells, rather than the intercellular structure, 
 are especially involved. Colloid resembles mucin in ap- 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 237 
 
 pearance, but unlike it contains sulphur and is precipi- 
 
 FlG. 189. 
 
 Softening of cartilage. Vertical section of an articular cartilage in raalum senile ar- 
 ticulorum. 1-300. After RESDFLEISCH. 
 
 FIG. 190. 
 
 Softening of bone. Fragment of bone from the spongy substance of an osteomala- 
 cious rib. a. Normal osseous tissue ; 6. Decalcified osseous tissue ; c. Haversian canals ; 
 d. Medullary spaces; d*. A medullary space filled with red medulla. 1-300. After 
 RIXDFLEISCH. 
 
238 
 
 THE MICROSCOPIST. 
 
 FIG. 191. 
 
 tated by acetic acid. It resembles jelly or half-set glue. 
 It first appears as a small globule in the 
 cell, which grows, pushing aside the nu- 
 cleus, until it not only fills the cell but 
 swells largely, communicating with neigh- 
 boring cells so as to form cystlike cavi- 
 ties containing the gelatinous substance. 
 Here it rnay afterwards undergo lique- 
 faction (Fig. 191). 
 
 The colloid change is most common in 
 enlargements of the thyroid gland, in the 
 lymphatic glands, and in many of the 
 new formations. Colloid or nmcoid tu- 
 mors, or tumors which have undergone 
 these forms of transformation, are some- 
 
 Colloid degenerat- 
 ingcells from a colloid 
 cancer After RLND- 
 
 FLEISCH. 
 
 FIG. 192. 
 
 Colloid degeneration in the strotna of an ovarian cystoid. a, a. Larger cysts, whose 
 walls bear an incomplete epithelium of low cylindrical cells whose contents after hard- 
 ening is split up radiating, b. Younger cysts without epithelium permeated by remains 
 of connective tissue fibres, c. The game with a wreath of loose epithelia d. Colloid 
 infiltration of the connective tissue which has not yet attained any cystoid appearance 
 and inclosure. e. Small-celled infiltration of the stroma. 1-200. After RINDFLEISCH. 
 
THE MICROSCOPE IX PATHOLOGY. 239 
 
 times called colloid cancers, when their structure may be 
 altogether different from cancer. 
 
 Some forms of multilocular ovarian cysts depend, ac- 
 cording to Rindfleisch, upon a colloid degeneration of the 
 stroma of the ovary, wherein an epithelial proliferation 
 furnishes the foundations of the cysts. Such a case may 
 be termed a cystic colloid cancer of the ovary (Fig. 192). 
 
 THE INFILTRATIONS. 
 
 1. Amyloid Infiltration. 
 
 This is known also as lardaceous or waxy degeneration 
 and vitreous swelling. It consists of the infiltration of 
 some sort of albuminate from the blood, which is charac- 
 terized by its becoming brownish-red or violet color by 
 treatment with iodine. It sometimes exhibits concentric 
 layers, like starch, which with the color phenomena led 
 Virchow to call it amyloid. 
 
 The amyloid infiltrated cell (Fig. 193) is distinguished 
 from the normal by its greater circumference, together 
 
 FIG 193 
 
 Amyloid infiltrated liver-cells, a. Isolated cells. 6. A fragment of the liver-cell net- 
 work, in which the dividing lines of the individual cells are no longer visible. 1-300. 
 After RIXDFLEISCH. 
 
 with a certain rounded irregularity. If several are in 
 contact they often coalesce into elongated lumps, in which 
 the individual elements counot be recognized. 
 
 The walls of small arteries and capillaries are the first 
 to be attacked in all infiltrations, and this is especially 
 observable in amyloid infiltration. Fig. 194 represents 
 partial amyloid infiltration of a Malpighian tuft of the 
 kidney. The blue injection, and of course the blood dur- 
 
240 
 
 THE MICROSCOPIST. 
 
 ing life, penetrates only the capillary loops which are free 
 from deposit. The addition of iodine, staining the amy- 
 loid matter red, gives an alternation of blue and red loops. 
 
 FIG. 194. 
 
 Amyloid infiltrated Malpighian vascular coil of the kidney. 1-300. After RINDFLEISCH. 
 
 Amyloid infiltration impairs the nutrition of a part 
 both by the obstruction of the circulation and by its 
 direct influence. Hence atrophy and fatty metamorphosis 
 are often found associated with it. 
 
 In lardaceous liver, or amyloid infiltration of the liver, 
 the minute branches of the hepatic artery are first affected, 
 then the region of the hepatic vein, and afterwards the 
 
 FIG. 195. 
 
 Amyloid liver. A. Interlobular artery with amyloid walls. G, G. Biliary ducts. 
 p,p. Portal vessels. V, V. Interlobular veins. The liver-cells in the central zones of 
 the acini are infiltrated with amyloid substance. 1-300. After EINDFLEISCH. 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 241 
 
 hepatic cells in the region of the portal vein, until the 
 whole organ may ultimately have twice as much solid 
 albuminous substance as normal, and becomes pale gray 
 in color, translucent, and of waxlike consistence (Fig. 195). 
 
 2. Calcification. 
 
 Calcification is the infiltration of tissue with solid phos- 
 phate or carbonate of lime. Free carbonic acid is solvent 
 of these salts, and by its capacity for diffusion it escapes, 
 leaving the insoluble salts in the nutritive fluid. 
 
 Thus cartilage normally becomes bone, and under pecu- 
 liar circumstances other tissues ossify. True osseous tis- 
 sue, however, differs greatly from mere calcification by 
 
 Arthritis uratica. Vertical section through a superficial articular body infiltrated with 
 urateoflime. a. The surface, ft. Cartilage cavities with tufts of crystals, c. Cartilage 
 cells not yet infiltrated, in division, d. Isolated needles of crystals in the basis-substance. 
 After CORXEIL ET RAXVIER. 
 
 the arrangement of its solid particles (see page 195). 
 Calcification of arteries is a secondary affection, succeed- 
 ing to fatty degeneration of the connective tissue. 
 
 Analogous to calcification is the arthritic deposit of 
 
 16 
 
242 
 
 THE MICROSCOPIST. 
 
 urates into articular cavities, and the parenchyma of the 
 cartilage, bones, and membranes of the joints of gouty 
 persons. It is most common in the cartilage cells (Fig. 
 196). 
 
 The uric acid infiltration acts as a mechanico-chemical 
 agent to the affected parts, producing oedema, suppura- 
 tion, caries, etc. 
 
 3. Pigmentation. 
 
 All true pigments are derived from the coloring matter 
 of the blood. Many of them are elimi- 
 nated by the kidneys and liver, but some 
 are deposited in the tissues, as the choroid 
 coat of the eye and the rete Malpighii of 
 the skin. Some pathological cases may 
 be ascribed to extravasation or some local 
 stasis in the circulation ; others may be 
 caused by wandering leucocytes (page 
 188). The brown atrophy of the muscu- 
 lar tissue of the heart, which is often as- 
 sociated with marasmus, is caused by the 
 
 FIG. 197. 
 
 muscular fibre (Fig. 197). 
 
 The dark pigment of the lungs owes 
 
 Brown atrophy of 
 heart-muscle. Frag- 
 ment of a membrane 
 
 of muscular fibres, deposit of yellow granular pigment in the 
 
 with pigment-gran- 
 ules in the interior 
 of the primitive bun- 
 dles. 1-300. After . 
 
 RINDFLEISCH. its origin chiefly to the respiration ot 
 
 carbon in the shape of particles of soot, 
 coal-dust, etc., floating in the atmosphere. These parti- 
 cles are first taken up by the mucous corpuscles (leuco- 
 cytes) of the trachea and bronchi, and many of them are 
 expectorated. Some, however, make their way to the 
 air-vesicles, arid penetrate the alveolar walls and inter- 
 lobular tissue (Fig. 198). 
 
 In the case of coal-miners the lungs often become uni- 
 formly black. "Workers in iron-dust are liable to have 
 the lungs stained red from oxide of iron, and stonecutters, 
 etc., to inhale and deposit silicic acid or fine sand. Such 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 243 
 
 particles produce irritation and inflammatory phenomena, 
 accompanying which is a formation of true pigment from 
 the blood, whose deposit increases the darkness of tint in 
 
 FIG. 198. 
 
 FIG. 199. 
 
 Anthracosis. Coal-dust inhaled into the alveolar septa of the lung. 1-3 JO. After 
 
 KlXDFLEISCH. 
 
 the lungs. Many morbid conditions, also, are attended 
 with formation of pigment. 
 
 4. Fatty Infiltration. 
 
 In this form of degeneration the fat is derived from the 
 food, and must be distinguished from 
 that metamorphosis called fatty degen- 
 eration. In fatty infiltration the fat 
 occurs in the cells as distinct drops of 
 oil (Fig. 199). 
 
 The vitality and functions of the cells 
 are but little impaired by the accumu- 
 lation, which may be again reabsorbed, 
 while in fatty metamorphosis the ele- 
 ments are destroyed. Fatty infiltra- 
 tion of muscle is seen in the connective 
 tissue between the fasciculi, and not in 
 the muscular fibres themselves as in fatty degeneration. 
 
 Fatty infiltrated liver- 
 cells. 1-300. After 
 RIXDFLEISCH. 
 
244 
 
 THE MICROSCOPIST. 
 
 The " fatty liver," as it is called, is due to infiltration. 
 The ingestion of fatty aliments is followed by temporary 
 accumulation of fat in the portal blood, which is apt to be 
 deposited in the portal capillaries of the liver, which is 
 gradually conveyed to the central or hepatic capillaries of 
 the lobules, and thus to the general circulation. In mor- 
 bid conditions, as in tuberculosis and heart disease, we 
 find the morbidly fatty liver first infiltrated in the portal 
 zone as in Fig. 200. 
 
 FIG. 200. 
 
 Fatty liver of moderate degree, serai-diagrammatic. V. Luraina of the central veins. 
 p. Interlobular branches of the vena portse. A. Arterial branches. G. Biliary ducts. 
 After RINDFLEISCH. 
 
 In more advanced cases all the liver-cells become filled 
 and the bounds of the acini are effaced. Fat may occur 
 in the liver in connection with general obesity, or from a 
 failure of the oxygenating power of the blood, in which 
 case there may be general emaciation. 
 
 5. Albuminous Infiltration. 
 
 Albuminous infiltration, or cloudy swelling, consists in 
 filling the tissues with molecular albumen. It is regarded 
 by Yirchow as a nutritive irritation, or an incitation of 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 245 
 
 cells to take up an abnormal amount of nutritive mate- 
 rial. It occurs after local and general irritations, which 
 bring to the part an increased supply of blood, and is es- 
 pecially important in the muscles and the large glands, as 
 the liver and kidneys. In the latter it is often associated 
 with fatty degeneration and fibrinous exudation, as in 
 Fig. 201. 
 
 FIG. 201. 
 
 1. Cloudy swelling and commencing fatty degeneration of the epithelia of the convo- 
 luted urinary tubuli. 2. Advanced laity degeneration. 3. Formation of fibrinous cyl- 
 inders, a. Cross-cut of a urinary tubul us, with a gelatinous cylinder filling the lumen. 
 b. Epithelium, c. Tunica propria. d. Renewed production of colloid at the surface of 
 the epithelial cells, which elevates the older. 1-500. After RINDFLEISCH. 
 
 6. Serous Infiltration. 
 
 This is an infiltration of the tissues with a serous or 
 sero-mucous substance producing oedema, and seems 
 analogous to mucoid degeneration. Under the micro- 
 scope bright spots appear in various cells, of which Wag- 
 ner declares it to be uncertain whether they are artificial 
 or diseased products, and if the latter, whether they are 
 serous, mucous, or colloid. 
 
246 THE MICROSCOPIST. 
 
 INFLAMMATION. 
 
 Inflammation is a complex process, beginning with an 
 increased flow of blood into or towards the part affected, 
 and generally leading to exudation or suppuration, some- 
 times healing by resolution or leading to new formations, 
 to various metamorphoses, or to destruction of tissues, 
 with a disturbance of the function of the part affected. 
 
 Inflammation of the various tissues or organs are dis- 
 tinguished by adding the termination itis to the Latin or 
 Greek term, as encephalitis, pleuritis, nephritis, etc. ; or a 
 special name is given, as pneumonia, for inflammation of 
 the lungs, erysipelas, for inflammation of the skin, etc. 
 
 Inflammations of serous coverings of organs receive the 
 prefix peri, as perihepatitis, perimetritis, etc. (except peri- 
 bronchitis, and peri phlebitis, which refer to inflammation 
 of the exterior of the bronchial or venous wall). Inflam- 
 mations of the surrounding connective tissue or appen- 
 dages of an organ are known by the prefix para, as para- 
 nephritis, paracystitis, parametritis, etc. 
 
 Inflammation is the result of some kind of injury to 
 the tissue affected, either direct, as from mechanical or 
 chemical agents, or indirect, as from specific contagions, 
 exposure to cold, etc. 
 
 The first phenomenon of inflammation is congestive 
 hypersemia, or an increased flow of blood. There is first 
 a dilatation of the vessels, with an acceleration of the 
 current, which is soon followed by a retardation of the 
 current, producing stagnation or cessation of circulation. 
 Several theories have been advanced to, explain this phe- 
 nomenon. According to the paralytic theory the irrita- 
 tion affects only the sensitive nerves, e. g., of the skin, 
 and produces an antagonistic paralysis in the vaso motor 
 nerves. The vessels then relax, dilate, and receive more 
 blood. According to Virchovv and Beale, it is the cell in 
 
THE MICROSCOPE IN PATHOLOGY. 247 
 
 itself without the intervention of the nerves or the blood, 
 which is excited to increased nutritive activity, to greater 
 metamorphosis, and to new formation ; and the more 
 quickly this takes place, the more it runs the danger of de- 
 struction, the more is the process to be looked on as in- 
 flammatory. There may be truth in both these views, 
 since the nutrition of the cell is so greatly influenced by 
 nerve action. 
 
 The second phenomenon of inflammation is exudation 
 and suppuration. The most disputed point respecting in- 
 flammation has been the genesis of pus-corpuscles. We 
 have seen, page 189, that they are identical in the living 
 state with leucocytes, or white blood-cells. In other words, 
 they are merely particles of bioplasm. Their migration 
 
 FIG. 202. 
 
 
 6 CL ft 
 
 Cohnheim's experiment, a. Vein. 6 6. Contiguous connective tissue, permeated by 
 migrating colorless blood-corpuscles, c. Column of red blood-corpuscles. 1-500. After 
 
 RlXDFLEISCII. 
 
 through the walls of bloodvessels was first described by 
 Dr. Addison in 1842, and afterwards, in 1846, by Dr. 
 Waller. These observations were forgotten, however, un- 
 til 1867, when Professor Cohnheim, of Berlin, showed the 
 
248 THE MICROSCOPIST. 
 
 importance of this migration to the pathology of inflam- 
 mation. His experiment consisted in stretching the mes- 
 entery of a living frog, paralyzed by the subcutaneous in- 
 jection of J per cent, solution of curare, over a ring of cork, 
 and placing it under the microscope. The veins are seen to 
 dilate, and the colorless blood-corpuscles first cling to the 
 inner surface of the wall of the vessel, then a process from 
 the bioplast passes through the wall, which swells up out- 
 side, and in this way a bridge is formed upon which the 
 whole substance of the cell creeps over. By their amoeboid 
 motions the cells wander further, and accumulate at the 
 irritated part of the tissue which becomes the point of de- 
 parture for future changes (Fig. 202). 
 
 Strieker has shown, by experiments on the tongue and 
 cornea of the frog, that the migratory cells, or pus-cor- 
 puscles, in inflammation increase by division. 
 
 Dr. Beale holds the opinion that although some of the 
 pus-corpuscles may be derived from the division of colorless 
 blood-cells, yet the great mass of them results from the 
 bioplasts of the tissues in which the pus-formation takes 
 place. In this he follows the earlier teaching of Virchow, 
 which supplanted the older view that pus-corpuscles origi- 
 nated in a structureless exudation. Dr. Beale recommends 
 the examination of a portion of cuticle raised by a small 
 blister, \vhich may be stained with carmine, or examined 
 fresh in the serum of the blister. The bioplasm of the 
 inflamed epithelial cells will be found larger than in the 
 normal state, and in some instances will be seen to project 
 beyond the formed material of the cells, and the free 
 portions divide and subdivide in the exudation poured 
 out from the bloodvessels. 
 
 In Chapter IX we have referred to Dr. Beale's views 
 respecting the elementary histological unit or cell, which 
 seem to agree with the phenomena recorded by Max 
 Schultze, Cohnheim, Strieker,* etc. So influential have 
 
 * Strieker's Manual of Histology, chap. i. 
 
THE MICROSCOPE IX PATHOLOGY. 249 
 
 been these views in pathology, that we quote from him 
 the following abstract concerning the changes in the cell 
 in disease: 
 
 " Of the different constituents of the fully formed cell, 
 the germinal matter is alone concerned in all active 
 change. This is, in fact, the only portion of the cell 
 which lives, while at an early period of development the 
 parts of the cell usually regarded as necessary to cell ex- 
 istence are altogether absent. The 4 cell ' at this period 
 is but a mass of living germinal matter, and in certain 
 parts of the body, at all periods of life, are masses of 
 germinal matter, destitute of any cell-wall, and exactly 
 resembling those of which at an early period the embryo 
 is entirely composed. White, blood, and lymph corpus- 
 cles, chyle corpuscles, many of the corpuscles in the spleen, 
 thymus, and thyroid, corpuscles in the solitary glands, in 
 the villi, some of those upon the surface of mucous mem- 
 branes, and minute corpuscles in many other localities, 
 consist of living germinal matter. There is no structure 
 through which these soft living particles may not make 
 their way. The destruction of tissue may be very quickly 
 effected by them, and there is no operation peculiar to 
 living beings in which germinal or living matter does no*t 
 take part. Any sketch of the structure of the cell would 
 be incomplete without an account of some of the essential 
 alterations which take place in disease, and it is therefore 
 proposed to refer very briefly to the general nature of 
 some of the most important morbid changes. 
 
 "If the conditions under which cells ordinarily live be 
 modified beyond a certain limit, a morbid change may re- 
 sult. For instance, if cells, which in their normal state 
 grow slowly, be supplied with an excess of nutrient pabu- 
 lum, and increase in number very quickly, a morbid state 
 is produced. Or if, on the other hand, the rate at which 
 multiplication takes place be reduced in consequence of 
 an insufficient supply of nourishment, or from other causes, 
 
250 THE MICROSCOPIST. 
 
 a diseased state may result. So that, in the great majority 
 of cases, disease, or the morbid state, essentially differs 
 from health, or the healthy state, in an increased or re- 
 duced rate of growth and multiplication of the germinal 
 matter of a particular tissue or organ. In the process of 
 inflammation, in the formation of inflammatory products, 
 as lymph and pus, in the production of tubercle and can- 
 cer, we see the results of increased multiplication of the 
 germinal matter of the tissues or of that derived from the 
 blood. In the shrinking, and hardening, and wasting 
 which occur in many tissues and organs in disease, we see 
 the effects of the germinal matter of a texture being sup- 
 plied with too little nutrient pabulum, in consequence 
 sometimes of an alteration of the pabulum itself, some- 
 times of an undue thickening and condensation of the 
 tissue which forms the permeable septum intervening be- 
 tween the pabulum and the germinal matter. 
 
 " The above observations may be illustrated by reference 
 to what takes place when pus is formed from an epithelial 
 cell, in which the nutrition of the germinal matter, and 
 consequently its rate of growth, is much increased. And 
 the changes which occur in the liver-cell in cases of cir- 
 rhosis may be advanced in illustration of a disease which 
 consists essentially in the occurrence of changes more 
 slowly than in the normal condition, consequent upon less 
 than the normal freedom of access of pabulum to the 
 germinal matter. 
 
 "The outer hardened formed material of an epithelial 
 cell may be torn or ruptured mechanically, as in a scratch 
 or prick by insects, or it may be rendered soft and more 
 permeable to nutrient pabulum by the action of certain 
 fluids which bathe it. Jri either case it is clear that the 
 access of pabulum, to the germinal matter is facilitated, and 
 the latter necessarily 'grows' that is, converts certain 
 of the constituents of the pabulum that come in contact 
 with it into matter like itself at an increased rate. The 
 
THE MICROSCOPE IN PATHOLOGY. 251 
 
 mass of germinal matter increases in size and soon begins 
 to divide into smaller portions. Parts seem to move away 
 from the general mass. These at length become detached, 
 and thus several separate masses of germinal matter, 
 which are imbedded in the softened and altered formed 
 material, result. In this way the so-called inflammatory 
 product pus results. 
 
 "It will be seen how easily the nature of the changes 
 occurring in cells in inflammation can be explained if the 
 artificial nomenclature of cell-wall, cell-contents, nucleus 
 be given up. In all acute internal inflammations a much 
 larger quantity of inanimate pabulum is taken up by cer- 
 tain cells and converted into living matter than in the 
 normal state. Hence there is increase in bulk; cells of 
 particular organs, which live slowly in health, live very 
 fast in certain forms of disease. More pabulum reaches 
 them, and they grow more rapidly in consequence. 
 
 "In cells which have been growing very rapidly and 
 are returning to their normal condition, in which the access 
 of nutrient pabulum is more restricted than in the abnormal 
 state, as is the case in normal cells passing from the em- 
 bryonic to the fully formed state, the outer part of the 
 germinal matter undergoes conversion into formed mate- 
 rial, and this last increases as the supply of pabulum be- 
 comes reduced. 
 
 " We will now inquire what alterations can be observed 
 in cells, the '-formed material' of which, under normal con- 
 ditions, becomes quickly resolved into other soluble con- 
 stituents if these cells be placed under circumstances 
 which caused the formed material to become harder and 
 less permeable to nutrient matter than in health. The 
 formed material which enters into the formation of the 
 liver-' cell' is soft, moist, and readily permeable to certain 
 nutrient matters. There is no cell-wall, but the outer 
 part of the formed material is gradually resolved into 
 soluble biliary matters, which pass down the ducts, and 
 
252 THE MICROSCOPIST. 
 
 into amyloid and saccharine matters, which permeate the 
 walls of the vessels and enter the blood. To make up for 
 the disintegration of the outer part of the formed mate- 
 rial, new formed material is produced in the interior of 
 the cell from the germinal matter, and the germinal mat- 
 ter which undergoes this change is replaced by new germi- 
 nal matter produced from the pabulum that is absorbed. 
 If such cells and their descendants are bathed with im- 
 proper pabulum, and especially with substances which 
 render albuminous matters insoluble, or possess the prop- 
 erty of hardening them (as alcohol), they necessarily di- 
 minish in size, in consequence of the formed material be- 
 coming less permeable, less nutrient matter is taken up; 
 and, of course, as the formed material becomes hardened, 
 less disintegration takes place, the quantity of secretion, 
 which really consists of the products resulting from dis- 
 integration, is much diminished, and the amount of work 
 performed by the cell is reduced. Under the supposed 
 conditions the cells shrink in size and become more firm 
 in texture. Many gradually waste, and not a few die, 
 and at length disappear. These seem to be the essential 
 changes which slowly take place in the liver-cells in cir- 
 rhosis^ and to these changes in the cells the striking 
 shrinking and condensation of the whole liver, so charac- 
 teristic of this disease, are due. 
 
 "From these observations it follows that disease may 
 result in two ways either from the cells of an organ 
 growing and multiplying faster than in the normal state, 
 or more slowly. In the one case the normal restrictions 
 under which growth takes place are diminished; in the 
 other the restrictions are greatly increased. Pneumonia, 
 or inflammation of the lung, may be adduced as a strik- 
 ing example of the first condition, for in this disease mil- 
 lions of cells are very rapidly produced in the air-cells of 
 the lung, and nutrient constituents are diverted from 
 other parts of the body to this focus of morbid activity. 
 
THE MICROSCOPE IN PATHOLOGY. 253 
 
 Contraction and condensation of the liver, kidney, and 
 other glands, hardening, shrinking, and wasting the mus- 
 cular, nervous, and other tissues, are good examples of 
 the second. The amount of change becomes less and less 
 as the morbid state advances, the whole organ wastes, 
 and the secreting structure shrinks, and at last inactive 
 connective tissue alone marks the seat where most active 
 and energetic changes once occurred. It is easy to see 
 how such a substance as alcohol must tend to restrict the 
 rapid multiplication of the cells if the process is too ac- 
 tive, and how it would tend to promote the advance of 
 disease in organs in which rapid change in the cells char- 
 acterizes the normal state. "* 
 
 Xon-living pus-corpuscles are round and granular, about 
 ^Q-gth of an inch in diameter. Dilute acetic acid renders 
 them transparent, and brings into view one or more nu- 
 clei, bright and sharply denned. Neutral alkaline salts 
 shrivel the pus-globules ancl caustic alkalies destroy them- 
 Besides the globules, pus often contains free nuclei, red 
 blood-corpuscles, epithelium, remains of connective tissue, 
 crystals of the triple phosphates, infusoria, etc. The in- 
 spissation of pus sometimes results in a cheesy metamor- 
 phosis or caseation, which has been called tuberculization of 
 pus (see the section on Fatty Degeneration, page 233). 
 
 In addition to pus-cells, there is in inflammation always 
 more or less fluid exudation, or inflammatory effusion. 
 This differs from the ordinary liquor sanguinis of the ves- 
 sels in health by containing a larger proportion of albu- 
 men and flbrinogenous substance, as well as an excess of 
 phosphates and carbonates. This exudation may be in- 
 terstitial when between the tissues and parts, parenchym- 
 atous if seated within the tissues so as to enlarge them, 
 or free if on free surfaces or natural cavities. 
 
 Serous exudations on free surfaces are called flux or 
 
 * The Physiological Anatomy and Physiology of Man, by Todd, 
 Bowman, ancl Beale. Part I. 
 
254 THE MICROSCOPIST. 
 
 serous catarrh ; into serous cavities inflammatory dropsy ; 
 into tissues, inflammatory oedema ; under the epidermis, 
 serous vesicles, etc. A serous exudation containing albu- 
 men is found in many inflammations of the kidneys (al- 
 buminuria), and of the intestine (dysentery), etc. 
 
 Mucous exudation, or mucous catarrh, occurs oftenest 
 on mucous membranes, from the mingling of the epithe- 
 lial cells with the increased flow from the vessels. The 
 term " catarrh " came from the ancient idea that in a cold 
 liquid flows from the ventricles of the brain through the 
 ethmoid bone and nose. 
 
 In catarrhal inflammation of the mucous membrane 
 there is first hypereemia, then swelling of the membrane 
 and lymph-follicles with an increased production of epi- 
 thelial and mucous elements. The excessive growth of 
 bioplasm in these elements, according to Beale, changes a 
 simple mucous catarrh into a purulent one (Fig. 203). 
 
 FIG. 203. 
 
 Catarrh (purulent) of conjunctiva, a. Epithelium, b. Connective tissue stratum of 
 the mucosa. After RINDFLEISCH. 
 
 In catarrhal (lobular or broncho) pneumonia there is a 
 proliferation of the alveolar epithelium of lobules or 
 groups of lobules connected with those bronchial tubes in 
 which the catarrhal changes first began (Fig. 204). 
 
 If the patient recover, but the retained substances are 
 incompletely removed, a thickening of the walls may re- 
 sult, with' the formation of a caseous nodule. 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 255 
 
 Desquamative catarrh of the kidneys, Fig. 205, begins 
 with a granular cloudiness and falling off of the epithe- 
 
 FlG. 204. 
 
 Catarrhal pneumonia. One and a half of an alveolus. The tortuous capillaries of 
 the septa injected. Filling of the lumina with epithelial cells of the walls which 
 multiply by division. 1-300. After RINDFLEISCH. 
 
 Hal lining of the uriniferous tubules, and an active prolif- 
 eration of the cells. 
 
 FIG. 205. 
 
 Transverse and oblique sections of catarrhal urinary tubuli. 1-500. After RIND- 
 FLEISCH. 
 
 Rindfleisch calls vesicles and pustules produced by in- 
 flammation of the skin, an acute purulent catarrh of the 
 skin, in which a primary serous catarrh (vesicle) became 
 a purulent one (pustule). Eczema he terms a chronic 
 
256 
 
 THE MICROSCOPIST. 
 
 catarrh of the skin, having its origin in hypersemia of the 
 papillary layer (Fig. 206). 
 
 FIG. 206. 
 
 Vertical section through the skin after chronic eczema, a. Horny layer, b. Mucous 
 layer of epidermis, c. Pigmented stratum of cylindrical cells, d. Papillary layer, e. 
 Cutis pervaded by stripes of pigmeat. After RINDFLEISCH. 
 
 The stratum of Malpighi in the skin is analogous to 
 the softer epithelium of mucous surfaces, hut catarrhal 
 processes in the skin are modified by the horny layer, 
 which is first destroyed in the instances referred to, and 
 then the multiplying epithelium cast off. 
 
 Fibrinous exudation consists of fluid from the hyperae- 
 iriic vessels, which coagulates into fibres between whose 
 meshes serum is confined. Pus-corpuscles are generally 
 mixed with the exudation, constituting a fibrino-purulent 
 exudation. These occur principally on the surface of serous 
 membranes. The coagulated fibrin either glues the two 
 surfaces of the membrane together, or forms a slightly 
 adherent layer of membrane, in which the exuded cells 
 develop a true connective tissue (Fig. 207). 
 
 The false membranes which occur in pleuritis or peri- 
 carditis, generally of rheumatic origin, are examples of 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 257 
 
 this result. The formation of pus in serous cavities (em 
 physema, etc.) is well illustrated in Fig. 208. 
 
 FIG. 207. 
 
 Adhesive inflammation. Diaphragmatic pleura, a. Contiguous muscular structure of 
 diaphragm. 6. Subserosa. c. Serosa. d. Boundary of the aerosa and the exudation, e. 
 Exudation. 1-400. After RINDFLEISCH. 
 
 Qwupous exudation differs from fibrinous by having its 
 origin in a peculiar metamorphosis of epithelium (Fig. 
 
 FIG. 208. 
 
 Purulent inflammation upon the serosa of the uterus, a. Serosa infiltrated with color- 
 less blood-corpuscles. 6. Surface secreting pus-corpuscles, c. Muscular structure. 1-500. 
 After RIXDFLEISCH. 
 
 209). Wagner has shown that this change in the cells re- 
 
 17 
 
THE MICROSCOPIST. 
 
 suits in a delicate network, forming by its accumulation 
 a flat grayish-white croupous membrane, or isolated de- 
 posits. According to this view, the network of croup- 
 
 FIG. 209. 
 
 Fibrinous degeneration of pavement cells. After E. WAGNER. 
 
 membrane occupies the place of epithelium. Other pathol- 
 ogists regard the network as analogous to the fibrinous 
 network of inflamed serous membranes. Croup of the 
 
 FIG. 210. 
 
 Croup of the trachea, a. The undermost layer of pseudo-membrane, b. The base- 
 ment membrane, c. The subepithelial germinal tissue, d. Excretory duct of a mucous 
 gland, from which a clear mucus is evacuated and lifts off the pseudo-membrane. 1-1000. 
 After RINDFLEISCH. 
 
 larynx and trachea shows a combination of catarrh and 
 pseudo-membranous exudation (Fig. 210). 
 
THE MICROSCOPE IN PATHOLOGY. 259 
 
 Croupous pneumonia is generally an independent affec- 
 tion, while the catarrhal and interstitial forms of inflam- 
 mation of the lungs usually result from preceding bron- 
 chial or pulmonary lesion. The first stage is that of 
 engorgement, in which the capillaries dilate and coil so 
 as greatly to diminish the air capacity of the alveoli. In 
 the second stage, that of red hepatization (Fig. 211), the 
 
 FIG. 211. 
 
 Kecent croupous pneumonia, a. Alveolar septa with injected capillary vessels. 6. The 
 exudation. 1-300. After RIXDFLEISCH. 
 
 exuded contents of the capillaries of the air-cells, red and 
 white corpuscles, and serum, are coagulated by the fibrin 
 into a solid body. The third stage is that of yellow or 
 gray hepatization, characterized by a greater proportion 
 of white blood-cells and their progeny, mingled with the 
 results of commencing fatty metamorphosis. Purulent 
 infiltration, or resolution, is sometimes called the fourth 
 stage of this disease. Here the fibrin melts down to a 
 soft amorphous gelatin, and the young cells undergo fatty 
 degeneration. Granular pigment also is mixed w T ith the 
 
260 THE MICROSCOPIST. 
 
 softened matters, and appears in the expectoration (Fig. 
 212). Instead of resolution, in which the exudation is 
 absorbed or cast out by the sputum, abscess, or gangrene, 
 or chronic pneumonia may result, though rarely. 
 
 Diphtheritic exudation accompanies a greater hypersemia 
 of the mucous surface than croupous inflammation, and 
 even of the submucous tissue, with a gangrenous separa- 
 tion of the infiltrated parts. Between the croupous and 
 diphtheritic forms of exudation there is every possible 
 transition. 
 
 FIG. 212. 
 
 Croupous pneumonia in a later stage of development. Melting down of the exudation. 
 Catarrhal desquamation of the alveolar walls. 1-300. After RIXDFLEISCH. 
 
 Buhl regards diphtheritis as a general disease, which 
 may be termed acute tissue necrosis, and is different from 
 inflammatory, typhous, scarlatinous, or other forms of 
 tissue necrosis. 
 
 The occurrence of fungi in diphtheritic exudation is 
 almost constant. The leptothrix buccalis is the most com- 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 261 
 
 mon form. Similar forms occur in croup-membrane. 
 Some suppose the fungus to be the primary cause of the 
 disease, but the decaying morbid matter may merely form 
 the habitat (see page 136). 
 
 RESOLUTION AND ORGANIZATION. 
 
 If the injury sustained by the tissue is not severe, or 
 by medical skill the vascular activity is lessened, the in- 
 
 o o 
 
 Section through the border of a healing surface of granulation, a. Section of pus. 
 b. Tissue of granulation (germinal tissue) with capillary loops, whose walls consist of a 
 longitudinal layer of cells, decreasing in thickness from within outwards, c. Beginning 
 of the cicatricial formation in the deep layers (spindle-cell tissue), d. Cicatricial tissue. 
 e. Complete epithelial covering. The central layer of cells consists of serrated cells. 
 /. Young epithelial cells, g. Zone of differentiation. 1-300. After RPXDFLEISCH:. 
 
 flammation may gradually subside or terminate in reso- 
 lution. The congestion diminishes, the emigration ceases. 
 
262 THE MICROSCOPIST. 
 
 some of the cells undergo fatty degeneration and are ab- 
 sorbed, others are removed loy the lymphatics, and the 
 tissue returns to its normal condition. 
 
 If the inflammation does not end in resolution, after a 
 diminution of intensity, there may be an organization of 
 many of the new cells into a form of fibrillated tissue, as 
 in the healing of wounds by u the first intention," and in 
 many chronic inflammations of the liver, kidney, etc. In 
 this cicatricial tissue the cells become spindle-shaped or 
 elongated, with tapering ends. Sometimes, according to 
 Green, a sort of adenoid tissue results, consisting of 
 meshes of fibrillated material inclosing lymphoid cells. 
 
 After suppuration, organization takes place by granu- 
 lation or the "second intention" It take's place wherever 
 the injured tissue presents a free surface to the air, as in 
 an ulcer, or in a wound left open, etc. (Fig. 213). The 
 young cells of the superficial layer develop into granula- 
 tion tissue, which forms little papilliform nodules or granu- 
 lations. The form of these granulations seems determined 
 by the new capillary bloodvessels which grow rapidly in 
 the new tissue. The deeper layers of the tissue gradually 
 develop into fibrillated tissue, while the cells on the sur- 
 face of the granulations and transuded liquid from the 
 vessels are discharged as pus. The first formation of epi- 
 thelium seems to consist of pus-corpuscles not thrown off, 
 yet the influence of the neighboring normal epithelium is 
 seen in the proliferating margins, as well as in the effect 
 of skin-grafting, as it is called, on the surface of an ulcer. 
 The new epithelium alwa} T s remains thin and dry. 
 
 PATHOLOGICAL NEW FORMATIONS. 
 
 Increased nutrition leads not only to the enlargement 
 of the component elements of a tissue, but also to the 
 production of new elements by proliferation of bioplasm 
 constituting new formations. These may be either in- 
 flammatory or non-inflammatory growths, occurring as 
 
THE MICROSCOPE IN PATHOLOGY. 263 
 
 tumors, infiltrations, or numerical hypertrophies, the lat- 
 ter differing from simple hypertrophies, or increased size 
 of the elements of tissues, by increase in the number of 
 the elements, as of the muscular fibres in hypertrophied 
 muscle, etc. 
 
 New formations are in all cases the direct product of 
 pre-existing cellular elements, and their development re- 
 sembles more or less the normal tissues. In other words, 
 every pathological growth has its physiological prototype. 
 If it is similar in structure and development to the tissue 
 from which it originates, or in which it is situated, it is 
 called homologous ; when it differs, heterdogous. 
 
 The elements from which new growths most frequently 
 originate are those of the common connective tissue, with its 
 bloodvessels and lymphatics. This tissue must be distin- 
 guished from formed connective substances, as bone, ten- 
 don, cartilage, etc. Two kinds of cells are found in this 
 tissue, the connective tissue cells, which are stable, and 
 the mobile cells, which are probably wandering leucocytes. 
 
 The first result of the abnormal activity of these cells is 
 to produce a new tissue, embryonic or indifferent tissue, 
 composed of small roundish cells, about 5 oWth of an inch 
 in diameter. This tissue afterwards develops into tissue 
 of permanent growth, resembling the immature connective 
 tissue of the embryo, and like that capable of becoming 
 fibrous tissue, cartilage, bone, etc. 
 
 Next to common connective tissue, the epithelia, surface 
 and glandular, are the elements from which new forma- 
 tions most frequently originate, and such growths gener- 
 ally resemble epithelium. 
 
 From the higher animal tissues, muscle and nerve, new 
 growths are rare, if, indeed, they really occur at all. 
 Beale says "the fully formed anatomical elements of a 
 normal tissue could not give origin to a morbid growth." 
 
 The term malignancy is applied to a property possessed 
 by many tumors of recurring after removal, of infecting 
 
264 THE MICROSCOPIST. 
 
 neighboring lymphatic glands, and of reproducing them- 
 selves in distant organs. It is not confined to carcinomas 
 or cancers, since many sarcomas are just as malignant. 
 
 Pathological new formations are subject to retrogressive 
 changes similar to those of physiological tissues. Deficient 
 supply of blood is followed by fatty degeneration, with its 
 varied terminations, softening, caseation, and calcifica- 
 tion. Pigmentary, colloid, and mucoid degeneration may 
 also occur, or inflammation. In addition, one form of 
 tissue may be transformed into another, especially of the 
 same group, as of connective tissue elements. Thus can- 
 cers may form in cicatrices and tumors of various kinds, 
 sarcomas in fibromas, etc. 
 
 Pathological new formations have been variously classi- 
 fied. For convenience of the student we divide them as 
 follows : 
 
 1. Pathological formation of cells 
 
 2. Pathological growth of higher animal tissues. 
 
 3. Pathological -growths of connective tissue origin. 
 
 4. Pathological growths of epithelial origin. 
 
 I. NEW FORMATION OF PATHOLOOICAL CELLS. 
 
 We have already stated that proliferating cells, either 
 tissue-cells or wandering leucocytes, produce abnormally, 
 first, an embryonic or indifferent tissue. This seems iden- 
 tical with granulation tissue (page 262). From it various 
 new growths proceed. The cells multiply as in normal 
 tissues, by division, budding, or endogenous formation 
 (page 125). Cell division affects the entire cell nucleus, 
 nucleolus, and bioplasm. It is generally accomplished 
 quickly, judging from experiments on the warm stage of 
 the microscope (page 42). Budding is a variety of self- 
 division, in which a small portion of bioplasm is protruded 
 and separated so as to become an independent cell. In 
 exogenous cell formation the nucleus, after previous di- 
 vision of the nucleolus, divides into two or more nuclei. 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 265 
 
 In the giant cells, so called, the nuclei number ten to fifty 
 or more. Physiologically these occur in bone marrow, 
 where they are regarded as transformed osteoblasts, and 
 pathologically in granulation tissue and many tumors. 
 In soft, yielding tissues their form is roundish, but in 
 fibrous tissues the giant cells have peripheral processes 
 (Fig. 214). 
 
 FIG. 214. 
 
 FIG. 215. 
 
 Giant cells, a. Roundish (Virchow). 6. With processes. From a muscular tumor 
 (Billruth). After RINDFLEISCH. 
 
 RindfleLsch has pointed out a cell-formation in nucleus- 
 bearing protoplasm, where apparently free nuclei are im- 
 bedded in homogeneous substance, but 
 reagents show a differentiation of the 
 protoplasm, so that to each nucleus 
 belongs a small round cell. This is 
 different from giant cells, and occurs 
 in many sarcomata and cancers (Fig. 
 215). 
 
 Most cells are capable of increase. 
 The movable and fixed cells of con- 
 nective tissue, young bone, and carti- 
 lage cells ; the youngest layers of epi- 
 thelial cells, either of the surface or 
 glandular; the nuclei of capillaries, of the sarcolemma, 
 
 Nucleated protoplasm. 
 Fragment from a granula- 
 tion. 
 
266 THE MICROSCOPIST. 
 
 etc., may any of them become points of departure for 
 pathological new formations. The youngest formed, or 
 embryonic cells, may be developed like the tissues of the 
 embryo, may become connective tissue cells, bone-corpus- 
 cles, muscle-fibres, and, according to some, true epithe- 
 lium, etc., or cancer-cells, sarcoma-cells, etc. The cells, 
 however, which rise from various tissues usually give 
 origin to definite new formations. Thus epithelial forma- 
 tions arise from epithelial tissue ; connective tissue forms 
 from connective tissue, etc. 
 
 II. PATHOLOGICAL GROWTHS OF HIGHER ANIMAL TISSUES. 
 
 1. Muscular Tissue. a. Striated. Virehow, and after 
 him Billroth and others, have shown that the elements 
 of the more highly organized tissues, as the nervous and 
 muscular, are rarely imitated pathologically. 
 
 Systematic writers term striated muscular tumors rhab- 
 domyoma, or true myoma. The few instances referred to 
 consist of a few fibres mixed with other tissues in cystic 
 tumors of the ovary, testicle, etc. 
 
 b. Smooth muscular-fibre tumors, or leiomyoma, fibroid, 
 in the narrower sense, occurring most frequently in the 
 body of the uterus, either as submucous, intramural, or 
 subperitoneal tumors, are so similar in their elements to 
 the ordinary fibroma as not to be distinguished from it. 
 
 2. Nervous Tissue. The term neuroma is applied to a 
 fibrous tumor on a nerve. It is quite doubtful if the term 
 is applicable. The cases recorded are small, roundish, 
 hard tumors, occurring in the course of nerves, and nod- 
 ules on nerves at the end of amputation stumps. They 
 consist, however, of increased vascular connective tissue 
 separating the nerve-fibres. Rindfleisch refers to a case 
 which he deems a true neuroma. He says it is the first 
 example of a genuine one, yet states that it may be a 
 hypertrophied ganglion of the sympathetic. 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 267 
 
 III. PATHOLOGICAL GROWTHS OF CONNECTIVE TISSUE 
 ORIGIN. 
 
 a. Common Connective Tissue Type. 
 
 1. Fibroma is a generally innocent growth, consisting 
 essentially of fibrous tissue (Fig. 216). Fibromata are 
 
 FIG. 216. 
 
 Transverse section of a fibroma of uterus. 1-300. a. Isolated cellular elements. 6. An 
 unravelled fasciculus of the fibroma. 1-500. After RINDFLEISCH. 
 
 usually circumscribed, rarely diffused, and are composed 
 of interlaced fibres and cells, like cicatricial tissue. The 
 common fibroid is so dense that in cutting it creaks under 
 the knife. 
 
 Fibromata occur on the trunk and extremities, proceed- 
 ing from the skin (as elephantiasis tuberosa, etc.), from the 
 subcutaneous and intermuscular connective tissue, from 
 fascia, periosteum, bones, and bone-marrow; in the uterus 
 and its vicinity, in subserous tissue, in submucous tissue, 
 especially of the nose and throat ; in nerves (as common 
 neuroma and the subcutaneous painful tumor, or irritable 
 tumor, as it is called) ; in glandular organs, as the mammae 
 and kidneys, etc. For the most part fibromata grow very 
 slowly, but they are often combined with other forms. 
 
268 
 
 THE MICROSCOPIST. 
 
 2. Areola fibroma, or fibre-cellular tumor, consists of 
 bundles of connective fibres with spaces containing serous 
 or mucous fluid. It occurs in circumscribed or diffuse 
 form. The circumscribed is found in the skin and sub- 
 cutaneous tissue, especially of the scrotum, labia majora, 
 around the vagina, in intermuscular connective tissue, 
 periosteum, uterus, mammae, etc. The diffuse occur often- 
 est in the skin as soft warts (fibroma molluscum, Fig. 217); 
 
 FIG. 217. 
 
 Fibroma molluscum. 1. Completed tissue, after Virchow. 2. Immature condition. 
 Formation of clefts in the pareiichymatous islands. 1-200. At a, the lumen of a vessel. 
 After KINDFLEISCH. 
 
 as elephantiasis of the scrotum, prepuce, labia, clitoris, of 
 the extremities, nose, etc. ; and as polypi in the submu- 
 cous tissue of the pharynx, nose, uterus, etc. 
 
 b. Mucous Tissue Type. 
 
 1. Myxoma, or mucous tumor, occurs either pure or 
 mixed with other tissues. It consists of a mucous basis- 
 substance, with stellate or spindle-shaped anastomosing 
 cells (Fig. 218), or in young myxomas, of small round 
 cells, like mucous corpuscles. Myxoma form rapidly- 
 growing, soft, knotty swellings, which may be mistaken 
 for soft cancers. They may be classed with benign tu- 
 mors, and do not return after thorough extirpation. 
 
THE MICROSCOPE IN PATHOLOGY. 269 
 
 Myxomata occur in subcutaneous and intermuscular 
 connective tissue, in fasciae, medulla of bones, and in the 
 interior and vicinity of glands. A myxoma of the pla- 
 centa has been described as a vesicular mole, consisting 
 in a hypertrophy of the mucous tissue of the tufts of the 
 chorion, producing tumors, varying to the size of a cherry 
 
 FIG. 218. 
 
 
 Hyaline myxoma of the subcutaneous connective tissue in the neighborhood of the 
 angle of the jaw. 1-3CO. After RIXDFLEISCH. 
 
 or larger ; the whole mass may attain the size of a man's 
 head. The fetal development in such a case varies ac- 
 cording to the mass of the tumors. 
 
 c. Vascular Connective Tissue Forms. 
 
 1. Angioma, or vascular tumor, is composed of blood- 
 vessels held together by a small amount of connective 
 tissue. The angiomata include the various forms of nsevi, 
 the erectile tumors, and aneurism by anastomosis. 
 
 (1.) Capillary angioma, naevus vasculosus, or teleangiec- 
 tasia, is generally congenital. It occurs oftenest on the 
 skin, in the papillary layer (mole, mother's mark, etc.), 
 although it may occur in other structures. It may vary 
 in size from that of a millet-seed to the occupancy of the 
 entire face or extremity. It is flat, lobed, generally bluish 
 or dark red, and consists of tortuous, varicose, or aneuris- 
 mal capillary vessels and wavy connective tissue. 
 
270 
 
 THE MICROSCOPIST. 
 
 (2.) Cavernous or venous angioma, erectile tumor, or 
 aneurism by anastomosis, is generally round, from the 
 size of a bean to that of a walnut. It is similar in struc- 
 ture to the erectile cavernous tissue of the penis and clit- 
 
 FIG. 219. 
 
 The substance of the cavernous tumor in full development. 1-300. From a cavernous 
 tumor of orbit. After RIXDFLEISCH. 
 
 oris, consisting of a network of fibres containing blood 
 (Fig. 219). They are generally of a bluish color. Venous 
 angiomata, consisting mainly of enlarged and tortuous 
 veins, are often seen as internal or external hsemorrhoidal 
 tumors. 
 
 (3.) Arterial angioma is sometimes met with, especially 
 in the branches of the temporal and occipital arteries. 
 
 (4.) Lymphatic angioma is a similar dilatation of the 
 lymphatic vessels, and has been principally noticed in 
 connection with elephantiasis. Lymphangiomata of the 
 kidneys and of the skin have also been described. 
 
 2. Thrombosis is a coagulation of the blood in the ves- 
 sels during life, from impeded blood-flow or changes (as 
 inequalities) in the walls of the vessels. It depends on 
 separation of the fibrin from the blood. Dr. Schmidt has 
 shown that the blood-corpuscles contain an albuminoid 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 271 
 
 substance (globulin, fibrino-plastic substance), which en- 
 ters into union with a similar (fibrinogenous) substance, 
 so as to form fibrin, the molecules of which have a great 
 attraction for each other, producing a characteristic mi- 
 croscopic network of round filaments. 
 
 Thrombi must not be confounded with the coagula 
 found in the dead. If the death-struggle has been long 
 coagula are generally found in the right side of the heart, 
 often extending into the pulmonary artery. A thrombus 
 is lighter, firmer, and drier than a coagulum, and is often 
 made up of concentric layers. 
 
 Cross-section through a thrombus by ligation of the crural artery, thirty-seven days 
 old ; hardened in alcohol, treated with dilute acetic acid, and then with a little ammonia- 
 or. Capillaries, b. The cell-net of the colorless blood-corpuscles. In the basis-substance 
 the contours of the red blood-corpuscles. After RIXDFLEISCH. 
 
 A thrombus once formed either organizes or softens. 
 
 If it organizes, the thrombus is gradually changed into 
 connective tissue. This is by virtue of the vital power 
 of the bioplasts, or white corpuscles. Thrombi have been 
 produced in animals by ligation, and cinnabar injections 
 into the blood have shown the wandering leucocytes, 
 carrying cinnabar, at work in the blood-clot. They send 
 out processes in various directions, which touch each 
 other and form a more delicate net with nuclei at the 
 points of intersection (Fig. 220). 
 
272 
 
 THE MICROSCOPIST. 
 
 Soon after vessels are formed in the thrombus, which 
 give it an organlike connection with the body, as other 
 pathological new formations. These vessels may widen 
 and become cavernous, as in Fig. 221, and as the walls 
 become thinner and finally disappear the thrombus ceases 
 to exist. 
 
 FIG. 221. 
 
 a 
 
 From the cross-section of an arterial thrombus of three months, a. Media, only the 
 innermost layers, b. Boundary lamella of the media and intiiua. c. Intima. d. Bound- 
 ary of intiiua towards the thrombus, e. Thrombus. /. Lumina of vessels. Distinct 
 epithelium. 1-300. After RINDFLFISCH. 
 
 The softening of the thrombi is a 'dangerous process. 
 Fragments may be carried from the radicles of the vena 
 cava through the right heart to the lungs ; from the radi- 
 cles of the pulmonary veins through the left heart to the 
 various organs of the body ; or from the radicles of the 
 portal vein to the liver. Such particles may occlude the 
 vessel in which they are found, producing embolism, the 
 results of which may depend on the mechanical obstruc- 
 tion to the circulation (anaemia and softening), or on 
 the irritating or infective properties of the emboli (pyae- 
 mia). 
 
 a. Adenoid or Eeticular Connective Type. 
 
 1. Lymphoma. This is a new formation of lymphatic 
 or adenoid tissue, and is generally found as small tumors 
 or infiltrations, consisting of rounded bright nuclei, and 
 
THE MICEOSCOPE IN PATHOLOGY. 
 
 273 
 
 small cells, like leucocytes, lying in semifluid or fibrous 
 intermediate substance. Lymphomata occur in typhoid 
 fever in tbe small intestine, in tbe mesenteric glands, and 
 liver. Lymphatic tissue always consists of a reticulum of 
 branched cells, within the meshes of which the lymphatic 
 corpuscles are contained. It is closely allied to embry- 
 onic tissue, and is easily influenced by any irritation 
 whatever to excessive development. Inflammatory states 
 
 FIG. 222. 
 
 From the section of tbe cervical gland of a dog, swollen to the size of a hazelnut after 
 artificially produced inflammation of tbe lips. 1-500. After Billroth. Connective tissue 
 septum. Sinus terminalis. Border of lymph alveoli. After RIN'DFLEISCH. 
 
 of tbe organs from which the glands receive their lymph 
 produce suppurative, cheesy, and indurated lymphade- 
 nitis (Fig. 222). 
 
 18 
 
274 THE MICROSCOPIST. 
 
 The adenomata are generally innocent. The glands 
 which are most prone to increased growth are the cervical, 
 submaxillary, axillary, inguinal, and abdominal glands. 
 Sometimes several glands unite so as to form large lobu- 
 lated tumors. The enlargement of the spleen in ague is 
 probably of this nature. Leucocythsemic new formations 
 occur generally in the spleen, the lymph glands, and per- 
 haps the medulla of bones. 
 
 2. Tubercle is an infiltrated or nodular new formation, 
 generally multiple, or miliary, non-vascular, round or ir- 
 regular, made up of large and small nuclei, indifferent 
 cells, and giant cells, imbedded in reticular tissue. After 
 long induration it passes into cheesy atrophy, or into soft- 
 ening, and produces not only local affections but also con- 
 stitutional disease (tuberculosis and scrofulosis). It was 
 formerly considered to be a specific non-inflammatory 
 growth originating spontaneously, and characterized by a 
 regular succession of changes, first gray and translucent, 
 then opaque, and finally caseous. Modern histologists re- 
 gard it as due to infection from the absorption of the 
 products of inflammatory processes. Caseation after fatty 
 degeneration page 233) may become a focus of self-infec- 
 tion, so that caseation and tubercle may occur side by 
 side. The nodules of tubercle are sometimes microscopic 
 in size, as in the liver or meninges of the brain. When 
 they reach the size of a millet-seed they are termed mili- 
 ary tubercles (gray tubercle, semi-translucent granulation). 
 If as large as a pea, cherry, egg, etc., they are large tuber- 
 cles or conglomerate nodules. Still later they are known 
 as yellow tubercles, from their being yellow and cheesy in 
 the centre. 
 
 In Fig. 223 is a vieV of two broncho-pneumonic depots, 
 the size of a millet-seed, illustrating a pseudo-tuberculous 
 condition. 
 
 See also page 254, where catarrhal pneumonia is stated 
 to precede a caseous nodule. 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 275 
 
 In contrast with this Fig. 224 shows the deposit of 
 miliary tubercle as it occurs iu tubercular meningitis. 
 
 FIG. 223. 
 
 Two smallest broncho-pneumonic depots. Tubercle granulation of Laennec. a, a. 
 The lumina of two adjacent small bronchi, the caseous secretion partially fallen out; 
 the walls infiltrated with cells and directly going over into catarrhal infiltration of the 
 surrounding parenchyma. By the coarse of the elastic fibres we may recognize every- 
 where how large the number of infiltrated alveoli is. &, b, b. Bloodvessels. 1-100 mm. 
 After RIXDFLEISCH. 
 
 The inflammatory growth originates in the perivascular 
 lymphatic sheaths which inclose the small arteries of the 
 
276 
 
 THE MICROSCOPIST. 
 
 pia mater. The cells of the sheath multiply, and numer- 
 ous gray nodules are produced around the vessel. 
 
 Microscopically, Wagner describes fresh miliary tuber- 
 cle as consisting of one or more (from four to six gener- 
 ally) rounded follicles or nodules, each composed of a 
 
 Vertical section through the pia mater and the contiguous portion of the cortex of 
 brain in tubercular meningitis, a, a. A larger vessel of the pia mater whose entire 
 sheath is innammatorily infiltrated. b,b. Lymph-spaces of the pia mater with com- 
 mencing tubercular proliferation of the endothelia. c. Miliary tubercle of the pia mater. 
 d. Outermost layer of cortex of brain infiltrated with round cells, e. Normal brain-sub- 
 stance. /,/. Proper cerebral vessels in a state of tuberculous degeneration. After RIND- 
 
 FLEISCH. 
 
 reticulum and cellular elements. The latter are free nu- 
 clei, cells like leucocytes with one or two nuclei, and in 
 the centre of the follicle one or more polynuclear giant 
 cells. The latter are granular and branching, with 20 to 
 100 rounded and comparatively large nuclei. In addition 
 there are cells of intermediate size, epithelial-like, rounded, 
 and finely granular. Tubercle always occupies the place 
 of normal tissue, which is either wasted or pushed aside 
 by it. 
 
 There may be atrophy or necrosis of the elements of 
 tubercle, after which cornification may transform it into 
 a hard horny mass. Resorption rarely occurs, but calci- 
 
THE MICROSCOPE IN PATHOLOGY. 277 
 
 fication will sometimes produce stony masses, which are 
 occasionally laminated. Most often softening or liquefac- 
 tion occurs simultaneously with cheesy metamorphosis, 
 leading on mucous surfaces to tuberculous ulcers, and in 
 the parenchyma of organs to tuberculous cavities or ab- 
 scesses. 
 
 e. Neuroglia or Nerve-cement Type. 
 
 1. Glioma is an increase of the elements of the finely 
 granular and reticular tissue or connective substance of 
 nerve. The nervous elements do not participate in it. 
 Glioma formerly went under the name of sarcoma, being 
 considered a variety of round-celled sarcoma, but the lo- 
 cality and origin of these tumors entitle them to separate 
 consideration. They are generally cerebral, and produce 
 symptoms of pressure or irritation. In the retina they 
 may begin as a white nodule, which grows until it may 
 project from the orbit as a large fungous tumor. Accord- 
 ing to the relative proportion of cells, intermediate sub- 
 stance, and vessels, they are divided into soft, hard, and 
 teleaugiectatic gliomas. Gliomas are of very slow growth, 
 and may become metamorphosed by haemorrhages, fatty 
 degeneration, and cystoid softening. Healing may be 
 possible through fatty metamorphosis. 
 
 /. Type of Fatty Tissue. 
 
 1. Lipoma. A general formation of new adipose tissue, 
 hereditary or acquired, is termed obesity. A local and cir- 
 cumscribed formation is a lipoma or fatty tumor. The 
 connective tissue unites the fat-cells in masses and lobules, 
 and forms a distinct capsule. Lipomata are sometimes 
 pedunculated. Their growth is slow, and although they 
 may attain considerable size they are perfectly benign 
 tumors. 
 
 Xanthoma, or xanthelasma, are small yellowish fatty 
 tumors of the skin, generally of the face or eyelids. They 
 
278 THE MICROSCOPIST. 
 
 are sometimes nodular, like millet-seeds or grains of wheat, 
 isolated or in groups. 
 
 g. Cartilage Type. 
 
 1. Enchondroma or Cartilaginous Tumor. Like carti- 
 lage, this consists of cells and intercellular substance, the 
 latter being hyaline, fibrous, or mucoid. The cells are 
 often spindle-shaped or stellate. Enchondromata rarely 
 develop from cartilage, but from bone and connective tis- 
 sue. A large majority have their seat upon bones, espe- 
 cially at the diaphyses of the long bones. They are usu- 
 ally single, except on the fingers and toes, where they are 
 often multiple. An ossifying enchondronia is called osteo- 
 chondroma. The enchondromata, especially those which 
 originate from cartilage, may be regarded as benign, yet 
 encapsulated forms originating from bone or connective 
 tissue are often injurious from the rapidity of their growth. 
 The softer forms, such as occur in the medulla of bone, 
 are sometimes malignant. 
 
 h. Type of Bone Formation. 
 
 1. Osteoma. An osseous or bony tumor. An outgrowth 
 from pre-existing bone is an exostosis or osteophyte. Such 
 outgrowths proceed from the periosteum, the articular 
 cartilage, or the medulla. In the latter case they might 
 be properly termed enostoses. These are homologous tu- 
 mors, since they are similar in structure to the tissue in 
 which they are found. The osteomata, however, may be 
 heterologous, as growing from connective tissue or carti- 
 lage apart from bone. They are of two kinds : 1. The 
 ivory or hard tumors, in which there is a marked absence 
 of cancellated bony tissue. 2. The soft or cancellous, 
 which are spongy. The medullary cavities are sometimes 
 quite large. 
 
 Osteomata are innocent tumors. Those osseous growths 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 279 
 
 which exhibit malignancy are ossified sarcomata or ossi- 
 fied cancers. 
 
 i. Other Forms Analogous to Connective Tissue Type. 
 
 1. Sarcoma. Fibro-plastic or fibro-cellular tumor. It 
 belongs to the group of connective substance tumors by 
 some of its affinities, but is to be distinguished by the 
 greater development of its cellular elements. All the 
 sarcomata consist of embryonic connective tissue, and the 
 
 FIG. 225. 
 
 Round-celled sarcoma, a. Vascular lumina. b. Parenchyma partly brushed out, so 
 that-the hardened baais-substauce appears as an elegant network. 1-300. After KIND- 
 FLEISCH. 
 
 several varieties are dependent on the size and shape of 
 the cells and the nature of the intermediate substance. 
 They include what are termed recurrent, fibroid, and mye- 
 loid tumors. 
 
 (1.) Round-celled sarcoma is allied to granulation and 
 embryonic tissues (page 262). 
 
 a. The granulation-like round-celled sarcoma, of soft con- 
 sistence, containing embryonic cells in a homogeneous or' 
 finely granular intercellular substance. 
 
280 
 
 THE MICROSCOPIST. 
 
 b. The lymphatic glandlike round-celled sarcoma exhibits 
 round cells in a delicate network of fibres among wide 
 thin-walled capillaries (Fig. 225). 
 
 There are several varieties of these lymphadenoid sar- 
 comas, as the lipomatous sarcoma, in which the cells by 
 infiltration are transformed into fat; the mucoid sarcoma, 
 from mucoid metamorphosis ; and the large-celled round- 
 celled sarcoma, which seems almost epithelial in its char- 
 acter of cells, with a large-meshed network. This tumor 
 is soft and brainlike, and may be easily confounded with 
 the following: 
 
 c. The Alveolar Round-celled Sarcoma. This has a great 
 resemblance to cancer, and has been called sarcoma carci- 
 nomatodes. It consists of groups of cells not connected 
 
 FIG 226. 
 
 Alveolar round-celled sarcoma, pigmented. 6. Alveolus from which the ball of round 
 cells has fallen out. c. Vessel with pigmented eridothelia. d. Piginented round cells. 
 e. Spindle cells forming a stroina. After RINDFLEISCH. 
 
 by basis-substance, but held in alveoli or clefts of connec- 
 tive tissue. The cells resemble epithelium. An exceed- 
 ingly malignant variety has been called pigmentary cancer 
 (Fig. 226). 
 
 (2.) Spindle-celled sarcomata are divided into a, small- 
 celled spindle-celled sarcomata (Fig. 227), which resembles 
 
THE MICROSCOPE IN PATHOLOGY. 281 
 
 the spindle-celled tissue of recent cicatrices ; 6, large-celled 
 spindle-celled sarcomata, in which the cells attain an ex- 
 cessive development (Fig. 2-8;; and c, the pigmentary sar- 
 comata. 
 
 FIG. 227. 
 
 Spindle-celled scarcoma. Gaping vascular luruina. The cell lines are divided partly 
 longitudinally, partly transversely. 1-300. After KLSDFLEISCH. 
 
 (3.) The giant-celled sarcomata, called also myelo-plastic 
 and myeloid sarcomas, contain large cells, with numerous 
 nuclei and nucleoli in a finely granular substance (Fig. 
 229). These occur usually on bones. 
 
 Sarcomata are rarely found in internal organs. They 
 usually arise from common connective tissue, and the 
 influence of locality on them is obvious. Thus on the 
 surface of bone we have osteoid sarcomata, pigmented 
 sarcomas in the skin and choroid, soft and gelatinous 
 sarcomata in the glands, etc. Complete cure sometimes 
 follows extirpation, but at other times there is a recur- 
 rence in the cicatrix, giving rise to the term recurring 
 fibroid. Like other tumors they may inflame or become 
 atrophied, or fatty metamorphosis, calcification, etc., may 
 occur in them. 
 
 2. Syj)hiloma. G-umma-syphiliticum. Gummy tumor. 
 
282 
 
 THE MICROSCOPIST. 
 
 This is a new formation, depending on constitutional 
 syphilis. Its essential elements resemble leucocytes im- 
 bedded in connective tissue wbicb is poor in vessels. 
 It exhibits many transitional forms to granulation tissue 
 
 FlG. 228. 
 
 Large-celled spindle-celled sarcoma. After VIKCHOW. 
 
 and sarcomata. Atrophy or fatty metamorphosis of the 
 cells may produce cavities or caverns and cicatricial marks 
 on the surface, leading to deformities (Fig. 230). 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 283 
 
 3. Lupus consists of nuclei and cells, forming a diffuse 
 or nodular infiltration of the corium of the skin, generally 
 
 FIG. 229. 
 
 Giant cells, a. Roundish (Virchow). 6. With processes. From a muscular tumor 
 (Billroth). After RIXDFLEISCH. 
 
 of the face, and sometimes of the bordering mucous mem- 
 
 FIG. 230. 
 
 Syphilis of liver, a. Left. b. Right lobe of liver, cc. Connective tissue sheath, which 
 penetrates the organ in the direction from the porta to the lig. suspensorium, and con- 
 tains gumiuata. 2-1. After RIXDFLEISCH. 
 
 braue. Rindfleisch considers it to begin with a luxuriant 
 
284 
 
 THE MICROSCOPIST. 
 
 cell proliferation in the interstitial and encapsuling con 
 nective tissue of the sebaceous and sweat glands (Fig. 
 231). If the skin appears normal, or there is a moderate 
 scaling till the lupus elements are resorbed, and there 
 is left behind a smooth or radiating cicatrix, it is called 
 lupus non exedens. Lupus exedens, or rodens, is ulcerative. 
 4. Lepra Elephantiasis Grcecorum. Leprosy formerly 
 prevailed all over Europe, but is now confined in that di- 
 vision of the globe to Iceland. Norway, the northern 
 
 FIG. 231, 
 
 Lupus. Section showing the transition of the healthy skin into the highest degree of 
 infiltration, a. Acinous alveoli, b. Germinal tissue of the lupus nodule, c. Metaplastic 
 hair-follicle and sebaceous gland. 1-10. After RINDFLEISCH. 
 
 provinces of Russia, and the borders of the Caspian and 
 Mediterranean seas. It still remains in Asia Minor, 
 Arabia, Egypt, India, China, and the Hawaiian Islands. 
 It is rarely cured, and generally destroys life by some sec- 
 ondary affection, as ansemia, diarrhoea, pneumonia, menin- 
 gitis, etc. 
 
 Li. tuberculosa, the common form, is characterized by a 
 nodular formation in the skin and other organs. The 
 microscope shows these to consist usually of round granu- 
 lar cells with granular albuminous intercellular substance 
 (Fig. 232). 
 
 These nodules soften and form ulcers, yielding a thin 
 sanious pus, which dries to a brownish crust. 
 
 In L. ancesthetica the nodules are absent, but there is 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 285 
 
 found on the spinal cord a thick yellow dense mass of a 
 diffuse leprous new formation, producing first paralysis of 
 sensation, and later of motion, with mummification and 
 necrosis of the skin, gangrene of fingers and toes, etc. 
 Sometimes both forms are combined in the same patient. 
 
 FIG. 232. 
 
 a. Lepra tissue, after Virchow. Cells in division. After ErxDFLEiscn. 
 IY. PATHOLOGICAL GROWTHS OF EPITHELIAL ORIGIN. 
 
 1. Papilloma Papillary or Villous Tumor. Papillom- 
 ata are analogous to the vascular papillae of the skin, 
 villi of the intestine, etc., and are composed of a vascular 
 connective tissue body or basis, covered with epithelium 
 (Fig. 233). 
 
 They form therefore a connecting link between the epi- 
 thelial and connective tissue types. The quantity of epi- 
 thelial growth varies in different papillomata In the 
 skin it is abundant, and the superficial layers are hard 
 and stratified, but in mucous membranes it is thinner and 
 softer, while in serous membranes it is only a single layer. 
 Papillomata of the skin include warts and horny growths ; 
 
286 
 
 THE MICROSCOPIST. 
 
 those of mucous membranes are often classed as mucous 
 polypi. The latter occur on the tongue, in the larynx 
 and nose, on the cervix uteri, etc. In the bladder and 
 intestine they are very vascular and produce profuse 
 
 FIG. 233. 
 
 A hyperplastic papilla of the cutis, together with epithelium, from the environs of a 
 cancroid of the lip. After RINDFLEISCH. 
 
 haemorrhage. Here they are often mistaken for villons 
 epithelioma, since the symptoms are similar and scarcely 
 distinguishable till after death. In the papillomata the 
 epithelium is homologous, being situated only on the sur- 
 face, and in no case growing within the connective tissue 
 basis. In the epitheliomata it is heterologous and is met 
 
THE MICROSCOPE IN PATHOLOGY. 287 
 
 with in the subjacent connective tissue. Yet a simple 
 papiiloma may develop into an epithelioma. 
 
 2. AJeriouia, or Glandular Tumor. This forms sharply 
 defined, and generally encapsuled, knots of new-formed 
 glandular tissue. Its structure resembles that of race- 
 mose or tubular glands, and consists of numerous saccules 
 or tubes lined with squamous or cylindrical epithelial 
 cells. These are grouped together, being separated by a 
 small amount of vascular connective tissue. 
 
 As sarcomata, myxomata, etc., occurring in glandular 
 organs, have more or less glandular tissue, it is often dif- 
 ficult to see which predominates, hence the terms adeno- 
 sarcoma, adeno-myxoma, etc. 
 
 Adenomata of the skin vary in size to that of an egg, 
 and originate from sweat or sebaceous glands. Rind- 
 fleisch considers lupus to be of this nature (see Lupus). 
 
 Adenomata of mucous membranes form mucous polypi, 
 which are usually broad, rarely pedunculated, and grow 
 from the size of a bean to that of a hen's egg. The sur- 
 face of such tumors is like that of the mucous membrane, 
 but internally it may be fibrous and vascular, or even 
 cystic. They occur on all mucous membranes, but often- 
 est in the nasal cavity, rectum, and uterus. The conse- 
 quences of these adenomata depend on their size and 
 anatomical relations. Thus they may form obstructions 
 and give rise to catarrh and haemorrhage. 
 
 Adenomata of glands occur more especially in the 
 mamma, parotid, prostate, liver, and thyroid. Adenoma 
 of the thyroid is known as goitre. Adenoma of the 
 mamma (Fig. 234) is called by Bill roth a " true epithelial 
 glandular carcinoma.' 7 The only difference between it 
 and a genuine epithelioma or carcinoma appears to be 
 that the proliferatien of the epithelium is confined to the 
 dilated glandular cavities, instead of infiltrating the sepa- 
 rating walls, as in cancer. 
 
 Some ovarian cysts myxoid or colloid cystomata 
 
288 THE MICROSCOPIST. 
 
 (page 239) belong to the adenomata. They proceed from 
 the rounded or elongated saccular epithelial masses which 
 form the processes of the Graafian follicles. 
 
 Adenomata are usually benign formations, but have a 
 tendency to pass into cancer. 
 
 3. Carcinoma, or Cancer. The term cancer is applied 
 to an epithelial new formation which may occur as a 
 tumor or infiltration in any tissue or organ, which is quite 
 
 Adenoma mammae. Genuine epithelial carcinoma (Billroth). 1-300. After EINDFLEISCH. 
 
 malignant, but which is generally (not always) chronic in 
 its course. Its cells are not peculiar, being similar to 
 other physiological cells, but by their rapid multiplication 
 and metamorphoses are followed by destruction of the 
 affected parts of the organ, and finally of the organ itself. 
 It usually returns after extirpation, or it may secondarily 
 affect internal organs. We have seen, page 264, that ma- 
 lignancy is by no means an exclusive property of cancers, 
 since other new formations may be equally malignant. 
 
 Cancer occurs in various forms, as scirrhus, encephaloid, 
 and colloid. Some consider epithelioma also to be a form 
 of cancer, but as it is not as malignant as other forms, 
 and is characterized by its local growth, it may be best 
 considered separately as cancroid rather than true cancer. 
 
THE MICROSCOPE IN PATHOLOGY. 289 
 
 Histologically, the forms of cancer resemble each other 
 in consisting of cells of an epithelial type, without inter- 
 cellular substance, grouped in irregular nests within the 
 alveoli of a fibroid stroma (Fig. 235). 
 
 The differences between various forms of carcinoma 
 are chiefly dependent on the greater or less proportion of 
 cells and fibrous stroma. The deposit of pigment, form- 
 ing melanotic cancer, as it is termed, may also be a cause 
 
 FIG. 235. 
 
 a 
 
 Brushed-out stroma of soft glandular cancer, a. Section of cylinder of cancer-cells. 
 b. Trabeculse of the stroma. c. A single spindle-cell, which extends from one trabecula 
 to another, and by the separation of basis-substance along its protoplasm gives the im- 
 pulse to the formation of a new trabecula of the stroma. d. Round-celled infiltrate in 
 the interior of the trabeculse of the stroma. 1-300. After RIXDFLEISCH. 
 
 of variety ; so also ossification of the stroma (osteoid cancer) 
 and the multiplication and enlargement of the vessels, as 
 in fungus hcematodes ; but for the purposes of study the 
 three forms referred to are sufficiently characteristic. 
 
 A difference of opinion exists as to the origin of the 
 epithelial-like cells in cancers. Billroth and others regard 
 them as starting only from pre-existing epithelium, while 
 Yirchow, Bindfleisch, etc., consider that they may be also 
 
 19 
 
290 
 
 THE MICROSCOPIST. 
 
 derived from connective tissue. It is not at all improba- 
 ble that any kind of bioplasts, as Beale maintains, may 
 form such growths by rapid proliferation, although the 
 weight of evidence justifies us in regarding epithelial 
 structure as the most frequent origin. The two follow- 
 in^ figures from Rindfleisch shows two different forms of 
 
 O O 
 
 origin in carcinoma of the liver. Fig. 236 shows the nor- 
 
 FIG. 236. 
 
 Carcinoma hepatis. The production and structure of pigrnented radiary caucer. The 
 liver-cell net forms the first foundation of the slroma, while the cancer-cells are de- 
 posited in the lumen of the vessels. 1-400. After RINDFLEISCH. 
 
 mal liver-cell as furnishing the first foundation of the 
 Btroma, while the cancer-cells are found in the vessels. 
 The liver-cells are generally pigmented. The spindle- 
 formed and stellate cells which are also seen in the more 
 delicate trabeculse of the stroma have nothing to do with 
 the liver-cells. In common cancer of the liver the vessels 
 form the origin of the stroma, while the cancer-cells come 
 from the liver-cells (Fig. 237). 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 291 
 
 (1.) Scirrhus. Hard, fibrous, or chronic cancer. This is 
 characterized by the large amount of its stroma and its 
 chronic growth. At the external surface of a scirrhus 
 tumor the microscope shows cells of indifferent, or granu- 
 lation, tissue infiltrated among the muscular or adipose 
 tissue of the part affected. At a little greater distance 
 within these cells have developed into nests of cancer- 
 
 FlG. 237. 
 
 a 
 
 Carcinoma hepatis. The production and structure of diffuse medullary cancer. The 
 vascular network forms the first foundation of the strorua, while the liver-cells are con- 
 verted into cancer-cells, a. Normal liver-cells, c. Parenchymatous inflammation. 6. 
 Nests of cancer-cells, v. Vena ceutralis. 1-400. After RIXDFLEISCH. 
 
 cells, while the interstitial inflammation has produced am 
 abundant stroma from the growth of pre-existent connec- 
 tive tissue, the trabeculte of which are pressed asunder 
 by the advancing cell-formation. Nearer the centre we 
 find the cancer-cells in a state of retrogressive metamor- 
 phosis, producing a diminution in the size of the alveoli, 
 and leading to a puckering of the external surface of the 
 tumor. Fig. 238 exhibits each of these stages. 
 
292 
 
 THE MICROSCOPIST. 
 
 Scirrhus is generally met with in the mammse and in 
 the alimentary canal. It is quite hard previous to pass- 
 ing into the ulcerative stage, and on section the tumor 
 exhibits a grayish-white glistening surface with occasion- 
 ally fibrous interlacing bands. Scraping the juice from 
 such a tumor may suffice for a cursory microscopic exami- 
 nation of its cells. 
 
 FIG. 233. 
 
 Carcinoma simplex mammae, a. Development of nests of cancer-cells, b. Fully formed 
 carcinoma tissue, e. Commencing cicatrization ; at the same time a representation of 
 the relations of stronia and cells in scirrhus. d. Cancer cicatrix. 1-300. After RIND- 
 FLEISCH. 
 
 (2.) Encephaloid. Medullary or acute cancer differs from 
 scirrhus in the rapidity of its growth, and consequent 
 softness of its structure. It is generally so soft as to be 
 brainlike, hence the term encephaloid. There are, how- 
 ever, all intermediate stages of hardness in cancers be- 
 tween the extremes of scirrhus and encephaloid. In the 
 latter epithelial growth is very rapid, and the proportion 
 of stroma small, while the abundance and softness of the 
 bloodvessels produces frequent haemorrhages. 
 
 Encephaloid occurs generally in the internal organs as 
 a secondary growth after extirpation of a cancerous 
 
THE MICROSCOPE IN PATHOLOGY. 
 
 293 
 
 tumor, although it may occur primarily also, as in the 
 articular ends of bones, in the eye, in the testicles, etc. 
 
 (3.) Colloid. Alveolar or gelatinous cancer. This form 
 depends on the metamorphosis of one of the preceding 
 forms, the cells of which undergo a mucoid or colloid 
 change. It is exceedingly malignant, and may occur in 
 the stomach, large intestine, liver, ovary, or mammary 
 gland (Fig. 239). 
 
 Fie . 239. 
 
 Carcinoma gelatinosum. 1-300. After RINDFLEISCH. 
 
 4. Epithelioma. Cancroid, or epithelial cancer, always 
 grows in connection with a cutaneous or mucous surface, 
 and its epithelial elements resemble the squamous variety 
 of epithelium so as scarcely to be distinguished from the 
 normal cell. They sometimes have more than one nu- 
 cleus, and are often flattened and distorted by mutual 
 pressure. They are not so ready to undergo fatty degen- 
 eration as the cells of other varieties of carcinoma. As 
 the cells multiply they have a marked tendency to be ar- 
 ranged concentrically in groups, forming globular masses 
 u epithelial pearls," "bird's-nest bodies," etc. (Fig. 240). 
 
 There is little doubt as to the epithelial origin of the 
 
294 
 
 THE MICROSCOPIST. 
 
 cells in epithelioma. It may be said of this structure, as 
 well perhaps of all varieties of carcinoma, that it is com- 
 posed of epithelium run mad, epithelium become heterol- 
 ogous, extending beyond its normal limits into subjacent 
 tissues. Epithelioma is first seen as a small foul ulcer 
 with indurated edges, or as an induration or nodule which 
 
 Section of a cylinder of epithelial cells, under a magnifying power of 500. a. The 
 cylinder itself, with the characteristic stratification of its cells, a younger and an older 
 pearly globule, ft. The stronia, very rich in cells at c, and contriimtiug directly to the 
 enlargement by apposition of the cylinder. After RINDFLEISCII. 
 
 subsequently ulcerates. The surface of the ulcer is often 
 villous, and the cut surface yields on pressure a small 
 quantity of turbid fluid, or a thick curdy material like 
 the sebaceous matter of the glands of the skin. This is 
 
 O 
 
 composed of epithelium. Epithelioma often occurs on 
 the lower lip at the junction of skin and mucous mem- 
 brane. It may also grow on the tongue, scrotum, etc., 
 and by its development may involve any tissue whatever. 
 Wagner describes three varieties of epithelioma : the 
 papillary, or warty pavement-cell cancer, whose surface 
 
THE MICROSCOPE IN DIAGNOSIS. 295 
 
 is similar to warts or pointed condylomata ; dcatricfal, 
 occurring usually in the skin of the face of old people as 
 a superficial slowly growing cancer presenting a cicatri- 
 cial contraction of the stroma from gradual retrogression 
 and reabsorption of the cells ; and the mucous cancroid, 
 or cylindroma, characterized by cylindrical or arborescent 
 masses of mucous substance. 
 
 The term cylindrical epithelioma has been given to those 
 forms which appear on mucous membranes with columnar 
 or cylindric epithelium. The tumors present the same 
 epithelial elements as the tissues whence they grow. The 
 walls of the alveoli show columnar epithelium, so that 
 the distinction between such tumors and simple adenom- 
 ata is very difficult. A variety of this form occurs as a 
 villous growth on mucous membranes, as the bladder, 
 uterus (cauliflower excrescence), and stomach. 
 
 CHAPTER XIV. 
 
 THE MICROSCOPE IN DIAGNOSIS. 
 
 IN diagnosis the microscopical observer is necessarily 
 confined to an examination of the various fluids and dis- 
 charges of the body. Dr. Pritcbard's microscope for ex- 
 amining the circulation of blood in the frsenum of the 
 human tongue, described by Dr. Beale, is an ingenious 
 attempt to investigate the actual condition of the living 
 subject, and indicates a direction which may hereafter be 
 profitably pursued, but as yet is too refined for the pur- 
 poses of the practical student. 
 
 I. THE BLOOD IN DISEASE. 
 
 The normal structure of blood has been sufficiently de- 
 scribed at page 186. It remains now to point out briefly 
 
296 THE MICROSCOPIST. 
 
 the methods of examination and considerations useful in 
 diagnosis. 
 
 The presence of too large a proportion of white corpus- 
 cles (leucocytes) in the blood constitutes what is known 
 as leucaemia, and is usually associated with morbid changes 
 in the spleen and lymphatic glands. But the relative 
 numbers of white and red corpuscles vary in different 
 persons, at different times, and in different morbid states, 
 so that great care is needed in forming an opinion. Thus 
 in anaemic and cancerous patients the proportion of white 
 corpuscles is increased. 
 
 Prick the skin of the finger with a needle after moderate 
 compression, and place the drop of blood thus obtained on 
 a perfectly clear slide, and cover with thin glass in the 
 usual way. ]S r o more blood should be taken than is suffi- 
 cient to fill the capillary space between the slide and cover. 
 The white corpuscles in the field of the microscope should 
 then be counted, or an estimate made of the proportion 
 of white to red corpuscles. 
 
 Several "fields" should be averaged before arriving at 
 an opinion. This is but a rough method, and for more 
 accurate determination a variety of tubes and slices have 
 been devised. The capillary apparatus of Dr. Malassez 
 is so constructed that one volume of blood diluted with 
 one hundred volumes of a ten per cent, solution of sul- 
 phate of soda, to facilitate enumeration and prevent co- 
 agulation, is placed in a capillary tube adjusted on a glass 
 slide so as to indicate a definite cubic capacity for a given 
 length, which relation is marked on the slide by the in- 
 strument-marker. Then, by means of an eye-piece mi- 
 crometer, divided into squares, the actual number of cor- 
 puscles, white and red, can be counted, and on multiplying 
 by one hundred for the dilution used, we have the figure 
 desired. Hayem and Cachet employ a slide having a 
 glass ring one-fifth of a millimeter in depth cemented on 
 it. A drop of blood diluted as above is placed in the cell 
 
THE MICROSCOPE IN DIAGNOSIS. 297 
 
 and covered with a flat glass cover. As soon as the cor- 
 puscles have settled to the bottom, the number in a defi- 
 nite area is counted. If the area chosen is one-fifth of a 
 square millimeter, we have, of course, one-fifth of a cubic 
 millimeter of diluted blood ready for enumeration by aid 
 of the ocular micrometer divided into squares as before. 
 
 Changes in the appearance of the globules, white or 
 red, should be noted, even though such changes are due 
 to physical causes, as crenated margins, not running to- 
 gether in rouleaux, etc. Minute particles of bioplasm (mi- 
 crocy tesl are sometimes seen, appearing as granular debris, 
 whose significance is unknown. In pernicious anaemia 
 globular cells, deeper in color and smaller than ordinary 
 red globules, have been observed. In a case reported by 
 Dr. Mackenzie the number of red disks was but 18.6 per 
 cent, or 930,000 to the cubic millimeter, instead of 5,000- 
 000 (page 187). 
 
 In the disease known as malignant pustule, splenic 
 fever, anthrax, etc., a short, straight, motionless rod, 
 about as long as the width of a blood-corpuscle, has been 
 found in the blood, and is definitely related to the activity 
 of the virus. It is called Bacillus anthracis, and resembles 
 a common and harmless one found in infusions of hay, 
 etc., the Bacillus subtilis, although the latter is endowed 
 with motion. 
 
 In relapsing fever, during the paroxysm and relapse, 
 but not in the interval, Spirilla are found in the blood. 
 They are minute spirals of great tenuity, and are from 
 two to six times the breadth of a blood-corpuscle. 
 
 The Filaria sanguinis hominis is found in the blood and 
 urine of persons affected with a certain form of chyluria. 
 It is about the breadth of a blood-cell, and ^ 5 th of an 
 inch in length. It exhibits active wriggling movements.* 
 
 * Finlayson's Clinical Diagnosis. 
 
298 THE MICROSCOPIST. 
 
 Dr. Cobbold states that its larval state is passed in the 
 stomach of the mosquito. 
 
 Dr. Beale has found cells similar to white corpuscles, 
 but larger, in cases of cholera and of pyaemia. Many of 
 these were too large to pass the capillaries. 
 
 The tendency of cells to adhere is thought by Beale to 
 depend on a reduction of the amount of water. He ob- 
 served such tendency to be increased after watery evacua- 
 tions by Epsom salts. 
 
 Dr. Coupland described corpuscles, of a red color, ^'o^th 
 of an inch in diameter in blood from a case of Addi son's 
 disease. They disappeared as the patient improved. 
 
 Dr. Lostorfer, of Vienna, professed to be able to distin- 
 guish syphilitic blood by the presence of peculiar bright 
 bodies in from one to five days after it had been taken 
 from the patient. The drop of blood on a slide, covered 
 with thin glass, is placed under a bell-glass arranged as a 
 moist chamber. In from one to five days, in addition to 
 vibriones, bacteria, and sometimes sarcina, there appeared 
 these bright bodies, some at rest and some vibratile. 
 Many of the larger ones were seen to increase by budding. 
 He calls them syphilitic corpuscles. 
 
 Epithelial elements from the lining of the bloodvessels 
 have been seen in the blood. Cancer-cells may in this 
 way be transferred to distant parts. Epithelial cells be- 
 coming impacted in the smaller vessels may give rise to 
 thrombosis and abscesses, as in puerperal and pysemic 
 fever. 
 
 Dr. Beale's researches upon the cattle-plague led him 
 to believe that particles of germinal matter (contagium) 
 introduced from without into diseased blood, and the 
 products of their decay, may give rise to local congestions 
 and various eruptions, as boil, carbuncle, and pustule. 
 
 Dr. Salisbury thinks that rheumatism may be detected 
 long before the appearance of active symptoms by the 
 excess of fibrin deposited in a drop of blood. He states 
 
THE MICROSCOPE IN DIAGNOSIS. 299 
 
 that cholesterin or nerve-fat may be seen in blood which 
 has been kept from one to three days, and that variations 
 in this, seen under the microscope, may throw light upon 
 disordered mental and nervous functions. He claims that 
 carbuncle, intermittent fever, enteric fever, and small-pox 
 are produced by fungi in the blood, which he names re- 
 spectively Crypta carbunculata, Gemiasma viridis, Byoly- 
 sis typhoides, and Ivy variolosa. 
 
 The examination of blood in disease requires patient 
 care and the employment of high powers, not less than 
 1000 diameters. As a field for original investigation, this 
 subject affords a most tempting opportunity to those who 
 have the leisure and skill to pursue it. The time may 
 come when more may be known of a patient's disease by 
 an examination of a drop of blood under the microscope 
 than is possible in any other way. 
 
 In medico-legal inquiries the decision whether a blood- 
 stain is of human blood or of one of the lower animals is 
 one requiring exceptional skill, if, indeed, it is at all 
 practicable. The differences given on page 187 are easily 
 enough seen, but the red disks in a dog, a rabbit, etc., so 
 nearly approach those of human blood in size, and the 
 appearance of corpuscles in the same drop varies so much 
 under high powers, as to lead to doubtful testimony before 
 a jury. Dr. J. G. Richardson believes it quite possible to 
 distinguish human blood, but at present few microscopists 
 agree with him. In a doubtful case it would be well to 
 scrape off from the slide half of the drop of suspected 
 blood, replace it with undoubted human blood, and pho- 
 tograph the disks, so that one-half in the field of view 
 would be known and ready for comparison with the other 
 half. 
 
 To detect the red corpuscles in a blood-stain, it is well 
 to soften the clot with glycerin diluted with water to the 
 specific gravity of serum, or a one per cent, solution of 
 salt may be used. If this fails, an attempt may be made 
 
300 THE MICROSCOPIST. 
 
 to obtain haemin crystals. A portion of the supposed 
 blood-clot is placed on the slide, and a drop of water con- 
 taining a trace of salt is added. A thin glass cover is 
 applied, and a little glacial acetic acid is allowed to flow 
 in and mix with the blood. Heat is applied until the 
 mixture almost boils. The slide is then placed under the 
 microscope, and the rhomboidal crystals may be observed 
 with a J-inch objective. 
 
 For microspectroscope appearances, etc., see page 102. 
 The guaiacum test, as it is called, depends upon the ozone 
 of the hsemaglobulin of the blood causing a bluish tint 
 in the solution of guaiacum. The tincture is made by 
 dissolving one part of the resin in six parts of alcohol of 
 eighty per cent. The bottles are to be only half filled, so 
 that the tincture may be in contact with the air. Strips 
 of white blotting-paper are soaked in this and the alcohol 
 allowed to evaporate. A weak solution of blood dropped 
 on the paper produces a blue color. This is only valuable 
 as a negative test, since other substances give the same 
 reaction. If no color is obtained, blood is not present. 
 
 ^ II. EXAMINATION OF URINE. 
 
 Healthy urine contains a variety of organic and inor- 
 ganic substances, as urea, uric acid, alkaline and earthy 
 salts, animal extractive, vesical mucus, and epithelial 
 debris. A drop or two evaporated on a glass slide will 
 show the crystalline matters, consisting of urea, urate of 
 soda, chloride of sodium, phosphates, and sulphates. 
 
 Before examining urine for the purpose of diagnosis, it 
 is necessary to be familiar with the appearance of the 
 contents of healthy urine, as \vell as of accidental sub- 
 stances which are likely to be met with, as fragments of 
 hair, wool, feathers, cotton, silk, and flax, particles of 
 starch, breadcrumbs, sand, vegetable fibres, etc. Igno- 
 
THE MICROSCOPE IN DIAGNOSIS. 301 
 
 ranee of the microscopic appearance of these common 
 things has led to ludicrous mistakes. 
 
 The amount of urine passed in each twenty-four hours 
 varies from 20 to 50 ounces, holding in solution from 600 
 to 700 grains of solid matter. The amount, both of solids 
 and fluids, varies according to the amount of fluids im- 
 bibed, the action of the skin, etc. The quantity of urine 
 should be considered in relation with its specific gravity, 
 since diminished urine with greater specific gravity may 
 occur in diarrhoea, etc., and imbibed fluids may cause 
 greater quantities with lessened specific gravity. 
 
 The average specific gravity of healthy urine is 1.020. 
 It may be measured by means of the specific gravity bot- 
 tle, or with the urinometer, a loaded glass bulb with 
 graduated stem. According to Dr. G. Bird, each degree 
 of the urinometer represents 2.33 grains of solids in 1000. 
 Thus specific gravity 1.020 represents 46.60 grains solid 
 matter, and 958. 40, water in 1000 of urine. 
 
 Another table of Dr. Bird's shows that the specific 
 gravity figures indicate nearly the amount of solids in 
 each fluid ounce. Thus 1010 shows 10 grains of solids, 
 1020 about 20 grains, etc. Yet this is only approximate. 
 
 High specific gravities (above 1025) are found in dia- 
 betes (from sugar), in concentrated urine from fevers or 
 other causes, in acute renal dropsy, and sometimes from 
 large quantities of albumen in solution. Low specific 
 gravities (below 1015) occur when the quantity is exces- 
 sive, especially in diabetes insipidus, in lardaceous disease 
 of the kidney, and chronic cases of Bright's disease. 
 
 UREA. 
 
 Urea is the vehicle by which nearly all the nitrogen of 
 the exhausted tissues is removed from the system, and 
 its retention is often attended with fatal ur?eniic poison- 
 ing of the blood. The quantity naturally eliminated de- 
 
302 THE MICROSCOPIST. 
 
 pends largely upon the amount taken in as food, but may 
 be stated generally as from 400 to 500 grains a day, or 
 8J grains per pound weight of the body. The specific 
 gravity of the urine usually gives an indication of the 
 quantity of urea excreted, since it is about one-third of 
 the amount of solid matter. 
 
 t If urea be suspected in excess, a drop of urine (concen- 
 trated and cold) may be put on a slide and a drop of nitric 
 acid added. On covering with thin glass and placing 
 under J-inch objective, the characteristic rhomboidal crys- 
 tals of nitrate of urea will be seen (Plate XXVI, Fig. 
 240). 
 
 Volumetric analysis is the best means of ascertaining 
 the quantity of urea as of other chemical ingredients, but 
 this falls rather within the province of the professional 
 chemist than of the microscopist. The practitioner may 
 estimate approximately by weighing the crystals of nitrate 
 of urea formed by adding nitric acid to double the quan- 
 tity of urine which has been concentrated to half its bulk. 
 
 CHLORIDES. 
 
 The chlorides are always present in normal urine. They 
 are diminished, and sometimes nearly suppressed, in sev- 
 eral febrile diseases, especially in pneumonia. The quan- 
 tity may be roughly estimated by acidulating the urine 
 with a few drops of nitric acid, and then adding a strong 
 solution of nitrate of silver. The density or abundance 
 of the precipitate, as compared with a sample of normal 
 urine, indicates the quantity ; or the precipitate maybe 
 weighed after being dried and fused in a porcelain capsule. 
 Albumen, if present, must be separated before testing for 
 chlorides, as it is also thrown down by nitrate of silver. 
 
PLATE XXYI. 
 
 FIG. 192. 
 
 FIG. 193. 
 
 
 
 
 Tube-casts. 
 
 Nitrate of Urea. 
 
 FIG. 194. 
 
 Urate of Ammonia. 
 
 FIG. 196. 
 
 Uric Acid. 
 
 Uric Acid. 
 
 FIG. 197. 
 
 
 Uric Acid re-precipitated. 
 
THE MICROSCOPE IN DIAGNOSIS. 303 
 
 BILE. 
 
 Bile in urine, if present in large quantity, can be recog- 
 nized by the eye. In testing for albumen by nitric acid, 
 the greenish color produced by bile will also attract notice. 
 A more delicate test consists in placing a drop or two of 
 urine and a drop or two of strong nitric acid near together 
 on a white plate and allowing one to run into the other. 
 As the acid mixes with the fluid, a play of colors, com- 
 mencing in green and terminating in red, passing through 
 various shades, will be observed. 
 
 Bile in urine indicates jaundice, and may aid in the 
 differential diagnosis of discolorations of the skin and 
 conjunctiva due to other causes. It may show an incipi- 
 ent jaundice before the tissues are generally affected, and 
 its disappearance may afford evidence that the attack is 
 passing off* when the effects of jaundice may be visible 
 elsewhere. 
 
 ALBUMEN. 
 
 In suspected albuminuria, samples should be examined 
 which were passed at different times of the day, as before 
 eating in the morning, and after eating in the evening. 
 Care should be taken to have clean bottles, test-tubes, etc. 
 The urine should be subjected to a double test, by boiling 
 in a test-tube and the subsequent addition of a drop or 
 two of nitric acid, and by the addition of strong nitric 
 acid to a separate portion of the cold urine. In the latter 
 test a cloudy ring of albumen appears at the junction of 
 the two fluids. 
 
 The quantity of albumen may be estimated sufficiently 
 for clinical practice by allowing the precipitate formed on 
 boiling to subside for a definite time, twelve to twenty- 
 four hours, and observing how much of the tube is occu- 
 pied, as a half, a fourth, an eighth, etc. 
 
304 THE MICROSCOPIST. 
 
 Sometimes albumen is due to the presence of blood, pus, 
 etc., as revealed by the microscope, and its significance 
 must be considered under these terms. Many acute febrile 
 diseases give rise to albuminuria, which may be regarded 
 as one feature of the general disturbance rather than of 
 local importance. 
 
 After the primary fever of scarlatina, and occasionally 
 after small-pox, enteric fever, and erysipelas, albuminuria 
 is present. It is not infrequent in pregnancy and the 
 puerperal state, and though not necessarily, yet often in- 
 dicates possible danger of convulsions during labor, chronic 
 renal disease, etc. 
 
 Chronic chest complaints are often complicated with 
 albuminuria, which has an important bearing on progno- 
 sis In such cases it may be only one of the indications 
 of a temporary general venous congestion, or it may indi- 
 cate a nephritis established through long-continued con- 
 gestion, or the renal disease shown by the albuminuria 
 may be primary and the thoracic affection a complication. 
 In all dropsies the presence of albumen is important. 
 Genuine renal dropsy rarely occurs without it, yet it may 
 be secondary and due to pressure on the renal veins 
 
 Albuminuria in acute or chronic renal disease must be 
 considered in connection with other urinary contents, as 
 tube-casts, epithelium, etc., and with alterations in quan- 
 tity, specific gravity, etc. 
 
 The significance of albuminuria in nervous diseases is 
 variable. It may be an effect of nervous disturbance, as 
 after a convulsion or from some lesion of the brain, or the 
 renal disease may be the cause of the nervous affection, 
 as in unemic coma or convulsions, etc. 
 
 We must look for albumen in the urine in many chronic 
 and constitutional affections, and transiently after the use 
 of blisters, etc. Where there are so many sources of 
 albuminous urine we must be guided by the general 
 symptoms, and particularly the presence of microscopic 
 
THE MICROSCOPE IN DIAGNOSIS. 305 
 
 deposits, derangements of quantity, and density in the 
 urine. 
 
 SUGAR. 
 
 Urine should be tested for sugar when diabetes is sus- 
 pected, or when the quantity is excessive, or the specific 
 gravity is high (above 1030). In some cases of cerebral 
 disease, also, sugar appears in the urine. The urine should 
 first be examined for albumen, since its presence is a serious 
 complication of diabetes, and it may interfere with the 
 reactions by the copper test. If present it should be re- 
 moved by boiling and filtration. Boiling albuminous urine 
 with crystals of sulphate of soda is said to render it suit- 
 able for the copper test, but the other way is best. 
 
 Copper Test Trommels Test. The urine is mixed with 
 a few drops of a solution of sulphate of copper in a test- 
 tube; excess of liquor potassse is then carefully added, 
 enough to just dissolve the precipitate it first throws 
 down ; the mixture is then boiled, and if sugar is present 
 a red precipitate of suboxide falls down. As errors occur 
 from not using the proper proportions, the following test 
 is preferred: 
 
 Fehling's Test Solution. Sulphate of copper, 90J grains ; 
 neutral tartrate of potash, 3t>4 grains; solution of caustic 
 soda (of specific gravity 1.12), 4 fluid ounces; add water 
 to make up 6 fluid ounces. (Or 40 grams of sulphate of 
 copper in crystals, 160 grams neutral tartrate of potash, 
 750 grams caustic soda, specific gravity 1.12; add water 
 up to 1154.5 cubic centimeters. Each 10 cubic centimeters 
 correspond to 0.05 gram of grape-sugar.) 
 
 A little of the test fluid is first boiled in a test-tube to 
 see if it remains unchanged in color, since it is apt to alter 
 by age. If unaffected, add a drop or two of the suspected 
 urine. If sugar be present in quantity the color changes, 
 and a yellowish or reddish precipitate falls. If no reac- 
 tion occurs, add a little more urine, but less than the 
 
 20 
 
306 THE MICROSCOPIST. 
 
 volume of test fluid, bojl it and cool; if no yellow or red 
 suboxide falls, it is free from sugar. Prolonged boiling 
 must be avoided, as well as boiling the urine before add- 
 ing the test. 
 
 To determine the quantity of sugar by the copper test 
 Fehling's solution is made of such strength that 200 grains 
 (by measure) are completely reduced by one grain of dia- 
 betic sugar. The test fluid is boiled in a flask, etc., and 
 a quantity of pure water equal to one or two volumes of 
 test fluid poured in also. The saccharine urine, diluted 
 with one volume urine to nine of water if suo;ar is abun- 
 
 O 
 
 dant, is placed in a burette, graduated to grains, and is 
 gradually added to the boiling copper solution till the 
 blue color is quite discharged. The number of grains of 
 urine consumed representing one grain of sugar is 
 read off, and it is then a matter of calculation how many 
 grains are contained in the ounce of urine, making allow- 
 ance for the degree of dilution. 
 
 O 
 
 .Fermentation Test. This is sometimes more convenient 
 or preferred from uncertain results of the copper -test. A 
 small tube is filled with suspected urine, a little fluid or 
 solid (German) yeast is added, and the tube is inverted 
 over a saucer containing urine and placed in a warm situ- 
 ation for twenty-four hours. If sugar is present it under- 
 goes fermentation, yielding alcohol and carbonic acid. 
 The latter rises in the tube and displaces the liquid. The 
 quantitative test by fermentation consists in determining 
 the specific gravity of the urine before and after complete 
 fermentation. It has been found, empirically, that one 
 degree of specific gravity lost by fermentation corre- 
 sponds with one grain of sugar per fluid ounce of urine. 
 
 Bismuth Test. Mix an equal volume of suspected urine 
 with a solution of carbonate of soda one part of the 
 crystals to three parts water (or with half as much liquor 
 potasspe). Put in a little basic nitrate, or subnitrate of 
 bismuth, and boil. If sugar be present the bismuth be- 
 
THE MICROSCOPE IN DIAGNOSIS. 307 
 
 comes grayish or blackish from the formation of the sub- 
 oxide or of metallic bismuth. 
 
 URINARY DEPOSITS. 
 
 Deposits from urine are either organic or precipitates 
 from solution. The urine should be put in a conical glass 
 of four or five ounces capacity, and kept free from dust 
 for about twelve hours. A small portion of the sediment 
 should then be taken up with a clean pipette and ex- 
 amined under the microscope on a glass slide covered in 
 the usual way (page 77). A quarter of an inch objective 
 will be found most generally useful. 
 
 To facilitate microscopical examination and diagnosis 
 we add the following table from Richardson's Medical 
 Jli'-roscopy : 
 
 I. A distinct deposit is seen in the urine. 
 
 A. This deposit is light and flocculent. 
 
 a. It occurs in albuminous urine, one yielding a coagu- 
 lum with heat and nitric acid. 
 
 a. The microscope shows casts of the uriniferous tubules 
 (transparent or granular cylinders s'^th to y^-^th of an 
 inch in diameter), either granular, epithelial, or hyaline, 
 Bright's disease of the kidney. 
 
 ,?. The microscope shows red blood-corpuscles (non-nu- 
 cleated disks gsVoth of an inch in diameter), mixed with 
 mucus, hcematuria. 
 
 Y. Leucocytes only are seen (nucleated corpuscles, pus- 
 corpuscles, o^o^th of an inch in diameter), nephritis, 
 cystitis, etc. 
 
 b. The urine is not albuminous. 
 
 a. Leucocytes, epithelial cells from the bladder, and per- 
 haps mucous casts of the tubules appear, irritation of 
 urinary tract. 
 
 ,''. Spermatozoa, if numerous, spermatorrhoea. 
 
 r- Fungous growths (cellular bodies j^th to 
 
308 THE MICROSCOriST. 
 
 of an inch in diameter, often arranged in chains, still, or 
 vibratile), pathological significance uncertain. 
 
 d. Hyaline and pale tube-casts (rare in non-albuminous 
 urine), Bright' 's disease. 
 
 B. Deposit dense, opaque, bulky. 
 a. Urine non-albuminous. 
 
 a. Microscopic deposit, granular simply, urates or phos- 
 phate of lime. The former dissolve on heating. 
 
 /?. Microscopic crystals, triangular prisms and their de- 
 rivatives, triple phosphates. 
 
 b. Urine albuminous. 
 
 . Leucocytes only, nephritis, cystitis, etc. 
 ft. Crystals of triple phosphates, with leucocytes, 
 chronic cystitis, perhaps calculus. 
 
 C. Deposit granular or crystalline; small. 
 a. Urine albuminous. 
 
 a. Red blood-disks, hcematuria. 
 
 /?. Cancer-cells (irregular, caudate, and oval, with large 
 nuclei), carcinoma. Mistake not epithelial for cancer 
 cells. 
 
 Y. Tubercle corpuscles (non-nucleated, granular, oval 
 bodies, about ^^th of an inch in diameter), tuberculosis . 
 
 b. Urine not albuminous. 
 
 a. Oxalate of lime crystals (brilliant octohedra. show- 
 ing as squares marked with diagonal crosses, or more 
 rarely as dumb-bells), oxaluria. 
 
 p. Uric acid crystals (yellowish, lozenge-shaped, oval, 
 barrel-shaped, etc.),lithuria. 
 
 r Microscopic spherules and dumb-bells, soluble in 
 acetic acid with effervescence, carbonate of lime. 
 
 d Hexagonal crystals of cystin, cystinuria. 
 
 e. Sediment resembling uric acid, but soluble in hot 
 water and mineral acids, xanthin. 
 
 C. Sheaflike bundles or globular masses of acicular crys- 
 tals, tyrosin and leucin, acute atrophy of liver? 
 7). Hydatids, etc., entozoa. 
 
THE MICROSCOPE IN DIAGNOSIS. 309 
 
 II. Urine turbid, without distinct deposit. 
 
 A. Turbidity disappears on warming, amorphous 
 urates. 
 
 B. Cloudiness remains while heating. 
 
 . Vibriones and bacteria present, putrefactive fermen- 
 tation. 
 
 ft Numerous minute molecules, chylous urine. 
 
 III. A film on surface of urine. 
 
 A. Prisms of triple phosphates, usually with granular 
 phosphates and spherules of urate of soda, phosphuria. 
 
 B. Numerous small oil-globules, with triple phosphates, 
 kiestin. 
 
 EPITHELIUM. 
 
 The character of the epithelial scales will often show 
 the locality of disease in the urinary tract (Fig. 142). 
 Penal epithelium, lying loose in the deposit is somewhat 
 globular, and may sometimes be compared with that in 
 the tube-casts in the same specimen Jt bears quite a re- 
 semblance to pus-cells. It occurs in desquamative nephri- 
 tis, and undergoes various changes, appearing atrophied, 
 granular, or fatty. Sometimes large granular corpuscles 
 occur with fatty epithelium, being altered cells them- 
 selves. 
 
 Cells from the bladder occur often as groups of tessellated 
 cells of circular form sometimes pyramidal. Caudate 
 epithelium is found in the ureter and pelvis of the kidney, 
 and may be caused by calculous pyelitis. Large scaly 
 epithelium comes from the vagina. 
 
 MUCUS AND PUS. 
 
 Mucus is deposited as a flocculent cloud, entangling a 
 few round or oval delicately granular cells, a little larger 
 than a red blood-globule. In disease this increases and 
 contains numerous ill-defined cells. A very thick glairy 
 
310 THE MICROSCOPIST. 
 
 deposit in disease of the bladder may be mistaken for 
 mucus when it is pus altered by the action of carbonate of 
 ammonia. 
 
 Pus is formed often from the germinal matter of epi- 
 thelium, so that a small quantity in urine is not neces- 
 sarily a sign of serious disease. In large quantities pus 
 forms an opaque cream-colored deposit, which becomes 
 glairy and tenacious by the addition of liquor potassse. 
 The addition of the latter will dissolve white urates, and 
 serves to distinguish pus from them as well as from phos- 
 phates, which are little affected by it. The microscope, 
 however, is the best test. 
 
 Purulent urine is usually acid if of renal origin (if tested 
 immediately), and is alkaline and ammoniacal in suppura- 
 tion from the bladder. Coexisting epithelium, etc., is 
 often of value in determining the origin of pus. Pus- 
 globules under the microscope, if long removed from the 
 body, are granular and show from one to four nuclei when 
 treated with acetic acid. In fresh pus-corpuscles, espe- 
 cially in warm weather, amoeboid motion is often seen. 
 In a late period of catarrh of the bladder but little epi- 
 thelium may accompany the discharge, but crystals of 
 triple phosphates occur generally in pus derived from the 
 bladder. 
 
 The clinical significance of pus in the urine is quite 
 varied. It may follow renal inflammation, and often ap- 
 pears in albuminuria following fevers and in renal em- 
 bolism. Abscesses opening into the urinary tract, cysti- 
 tis, cancer of the bladder, suppuration of the prostate, 
 gonorrhoea, and gleet may all give rise to purulent urine. 
 Accidental mixture from lochial or leucorrhoeal discharges 
 is also possible. 
 
 BLOOD. 
 
 Blood may sometimes be recognized by the eye in urine 
 from its smoky or dingy tint, especially in blood from the 
 
THE MICROSCOPE IN DIAGNOSIS. 311 
 
 kidney. Blood-disks usually form a reddish-brown de- 
 posit. The microscope will generally exhibit the disks, 
 unless they are greatly disintegrated, when we must be 
 guided by the quantity of albumen and other tests. 
 Blood in urine may proceed from some general disease af- 
 fecting the bloodvessels generally, or from some poisonous 
 agent acting on the kidneys, as cantharides, turpentine, 
 creasote, and alcohol, or from some local affection of the 
 urinary organs and passages. Of course the general symp- 
 toms of the patient must be considered, but sometimes 
 the kind of epithelium present may be a guide to the 
 source of the haemorrhage. 
 
 SPEKMATOZOA. 
 
 Spermatozoa, resembling tadpoles with elongated tails, 
 are not uncommon in perfect health, but nervous patients 
 are often deluded by quacks on account of them. Of 
 course, when present habitually and in large numbers 
 they may afford evidence of spermatorrhoea. 
 
 BACTERIA, FUNGI, ETC. 
 
 Bacteria and vibriones often appear in alkaline and 
 decaying urine. The sugar fungus (Torula), or yeast plant, 
 is developed when there are even minute traces of sugar. 
 Other fungi with branching growths are also frequent. 
 Some of these' may resemble tube-casts. Spores of globular 
 shape may be mistaken for blood-corpuscles. Sarcinse, or 
 minute cubic organisms, dividing into groups of four and 
 its multiples, are sometimes found in the urine of dyspep- 
 sia. 
 
 TUBE-CASTS. 
 
 In many cases of congestion and inflammation a coagu- 
 lable material is effused into the tubes of the kidney, 
 forming a cast or mould of the tube. This may be ejected, 
 bringing with it pus, blood, epithelium, or other material 
 
312 THE MICROSCOPIST. 
 
 with which it is associated. In Bright 's disease these 
 casts, in addition to albuminous urine, assume consider- 
 able clinical importance. In the acute form of the disease 
 the cylinders or casts are fibrinous, with blood, mucus, 
 or pus cells, and epithelium. Towards the close the casts 
 become homogeneous or hyaline. In chronic desquama- 
 tive nephritis the cylinders are without blood, arid to- 
 wards the end waxy or fatty, often containing many oil- 
 globules (Plate XXVI, Fig. 241). The specimen of urine 
 examined for casts should have settled for several hours, and 
 the drop of sediment examined should be carefully focussed 
 and illuminated. The casts are of various sizes, those of 
 very large diameter indicating dilation of the renal tubules. 
 In bloody or purulent urine tube-casts point out a renal 
 element in the case. They do not always indicate Bright's 
 disease, as they may be associated with the irritation of 
 a calculus, and are sometimes found in jaundice without 
 serious renal trouble or albuminuria. 
 
 CRYSTALLINE AND AMORPHOUS DEPOSITS. 
 
 Uric Add. Crystals of uric acid may often be recog- 
 nized as a red sand, lying at the bottom or on the sides 
 of the vessel, or entangled in mucus. They may be yel- 
 low, red, or brown, from coloration by urinary pigment. 
 Their microscopic forms are various, but are usually some 
 modification of the rhomb. Thus they may be rhomboid 
 tablets with obtuse angles, or the shape of a whetstone 
 (Plate XXVI, Fig. 242). When slowly precipitated, uric 
 acid may form druses of four-sided prisms (Plate XXVI, 
 Fig. 243). When precipitated from fresh urine by the 
 addition of muriatic acid, the crystals are large and often 
 of various shapes. They may be tested by dissolving in 
 potassa and reprecipitating by muriatic acid, when they 
 assume the shape of Fig. 244, Plate XXVI. Crystals of 
 uric acid may occur as a film as well as a deposit. They 
 originate from tissue-waste, excess of nitrogenous food, 
 
THE MICROSCOPE IN DIAGNOSIS. 313 
 
 defective assimilation, congestion of the kidney, or chronic 
 disease of the respiratory organs. 
 
 Urates or lithates are salts of uric acid combined with 
 soda, potash, or ammonia, the exact composition being 
 difficult to determine. Such sediments are very common. 
 They are generally amorphous, but sometimes crystalline 
 (Kate XXVI, Fig. 245). The urate of soda presents the 
 form of globules with projecting spiculae. The color is 
 various, from a light pink to brickdust color. It is de- 
 posited in all concentrated urine, and is often a "critical 
 discharge " in fevers, etc. It is found in gouty concretions, 
 and dissolves with heat and acids. 
 
 Phosphates appear in two forms, crystalline and amor- 
 phous. The crystalline are the crystallized phosphate of 
 lime, and the ammonio-magnesian (or " triple") phosphate. 
 The latter is most common, and may appear in any de- 
 composing urine. It may be precipitated from fresh urine 
 in stellate crystals (Plate XXVII, Fig. 246) by adding 
 ammonia. More slowly deposited from alkaline urine, or 
 in disease, the crystals are prismatic, generally triangular, 
 with truncated ends. Sometimes the truncated ends are 
 bevelled, and the various lengths of the prisms give rise 
 to a variety of forms (Plate XXVII, Fig. 247). 
 
 Triple phosphates are generally thought to proceed 
 from disintegrated albuminous, and chiefly nervous mat- 
 ter, but their clinica limportance is not fully settled. 
 They are found in cases of nervous depression, various 
 forms of dyspepsia, shock of the spinal cord, irritation of 
 the bladder, etc. 
 
 In highly alkaline urine the triple phosphates are often 
 accompanied with pus and phosphate of lime. The latter 
 occurs as minute granules or dumb-bells, or in groups of 
 crystals (Plate XXVII, Fig. 248). They are dissolved by 
 acetic acid, which distinguishes them from uric acid. 
 
 Oxalate of lime is deposited in small octohedra, gener- 
 ally appearing under the microscope as minute squares 
 with crossed lines proceeding from the angles, the upper 
 
314 THE MICROSCOPIST. 
 
 angle being next the eye (Plate XXVII, Fig. 249). 
 Dumb-bell forms and circular or oval crystalline masses 
 are sometimes seen. 
 
 Oxalate of lime is found as a urinary deposit in various 
 conditions, as in pulmonary and dyspeptic affections. It 
 is usual ly associated with hypochondriasis, and in cases 
 of overfatigue, particularly from mental work, it is com- 
 mon. The train of nervous and dyspeptic symptoms with 
 which it is associated have been supposed to indicate an 
 "oxalic acid diathesis," and have been named "oxaluria." 
 Its association with calculi renders it interesting to the 
 surgeon. 
 
 Chloride of sodium never crystallizes from fluid urine. 
 On evaporation it occurs in stellar form or in cubes (Plate 
 XXVII, Fig. 250). The presence of urea sometimes dis- 
 poses it to assume the form of a regular octahedron. The 
 amount of this excretion in typhoid fever and in inflam- 
 mations of the respiratory organs is greatly diminished. 
 It is absent in commencing hepatization of the lung, but 
 returns on resolution of the inflammation (see Chlorides, 
 page 302). 
 
 Cystin crystallizes in characteristic six-sided plates 
 (Plate XXVII, Fig. 251). It contains twenty six per 
 cent, of sulphur, and is considered a product of decompo- 
 sition. It is often associated with calculus. Some regard 
 it as indicating a strumous and ill-nourished system. 
 
 Carbonate of lime occurs rarely in human urine, but is 
 common in that of the horse. Its form is that of a 
 spherule made up of acicular crystals. It effervesces in 
 acetic acid. 
 
 Tyrosin, in sheaflike or globular masses, sometimes 
 occurs in typhus and in atrophy of the liver. 
 
 III. PUS AND MUCUS IN .DIAGNOSIS. 
 
 We have already considered the bioplasts of pus and 
 mucus as identical in character w r ith other leucocytes, as 
 
PLATE XXVH. 
 
 FIG. 198. 
 
 FIG. 199. 
 
 - 
 
 
 ses9l 
 
 
 -- 
 
 
 Ammonio-phosphate of Magnesia. 
 
 FIG. 200. 
 
 
 Phosphate of Lime. 
 
 FIG. 202. 
 
 P 
 
 D 
 
 Ammonio-phosphate of Magnesia. 
 
 FIG. 201. 
 
 Chloride of Sodium. 
 
 Oxalate of Lime. 
 
 FIG. 203. 
 
 )lDo 
 00 
 
 
 
 Cystine. 
 
 FIG. 204. 
 
 * 
 
 
 Salivary corpuscles, epithelial scales and granules. 
 
THE MICROSCOPE IN DIAGNOSIS. 315 
 
 the white blood-cells (see pages 189 and 309). They 
 are easily seen by the microscope in a drop of purulent 
 matter placed on a slide and covered by thin glass. Pus- 
 corpuscles shrink in size on being placed in liquid of 
 greater specific gravity than serum, and are destroyed by 
 the action of caustic alkalies so as to be changed into a 
 tenacious glairy mass. Dilute acetic acid causes them to 
 swell and become transparent, exhibiting from one to four 
 nuclei. Bacteria and their germs (microzymes) are often 
 seen with pus, and indicate commencing decomposition. 
 
 According to Dr. Beale, the figures and descriptions 
 generally given of pus represent dead, not living pus. He 
 recommends a little pus to be taken from suppurating 
 skin or mucous membrane and examined at once, in order 
 to see the projections from the bioplasts, by the detach- 
 ment of which they multiply. He considers the " mucous 
 corpuscle" to be nothing more than an imperfect epithe- 
 lial cell surrounded by the viscid mucus formed by, it. 
 This may grow rapidly, and the resulting particles become 
 true pus- corpuscles. 
 
 Richardson regards the difference between pus and 
 mucus to be that "the liquor muci is a secretion, which, 
 having been acted upon by the germinal matter of the 
 epithelial cells covering the basement mucous membrane, 
 is not albuminous, while the liquor puris is an exudation, 
 which contains albumen, that may be recognized by ap- 
 propriate tests." 
 
 IV. EXAMINATION OF MILK. 
 
 Examination of human milk may sometimes aid in 
 diagnosis, as in contusions of the breast, incipient mastitis, 
 and in the diarrhoea and innutrition of infants. The origin 
 of milk may be elucidated by the remarks on lactification 
 on page 233. 
 
 A thin stratum of milk should be examined with a 
 power of from 200 to 400 diameters, and an estimate 
 
316 THE MICROSCOPIST. 
 
 made of the milk-globules, as in the case of the blood- 
 eorpuscles ipage LtH> ; or the sample may be compared 
 with a specimen known to be healthy. 
 
 Impoverished milk is known by the small number and 
 Johules. Colostrum or "exudation " corpus- 
 cles are numerous shortly after childbirth. In engorge- 
 ment of the breast the globules aggregate in masses, and 
 sometimes from inflammation, blows, etc., blood and pus 
 may be found. Starchy adulteration may be detected by 
 the addition of iodine. Richardson speaks of tibrinous 
 casts of the lacteal ducts occurring after puerperal masti- 
 tis, and Peale of minute particles of contagious bioplasm 
 in the milk of a cow su tiering from cattle-plague, and 
 considers it possible that typhoid fever, etc., may be thus 
 propagated. 
 
 V, SA1 IV A ANP SIT TV M. 
 
 Besides the epithelium of the mouth, saliva holds in 
 suspension certain oval or spherical bodies, probably de- 
 rived from the glandular follicles, called salivary cor- 
 pus^ j.-e 1SOX 
 
 IV. Richardson considers them identical with leuco- 
 S, 1'eale supposes them to be concerned with the con- 
 version of starch into sugar, which occurs from the action 
 of the saliva. The peculiar dancing movement of the 
 granules of these corpuscles needs a ,',th if an inch object- 
 ii'lass. or one even higher, to see them well. 
 
 In examining sputum a small piece should be placed on 
 a slide and teased out with needles, if necessary, in glyc- 
 erin and water, or some indifferent fluid. AVe may ex- 
 pect to find mucus entangling air-bubbles and pavement 
 epithelium from the mouth (Plate X X V 11. Fig. 252), The 
 observer should, however, be familiar with the appear- 
 ance of fragments of food, starch, epithelium from the 
 various parts of the air-passages, fungi, etc. 
 
 In catarrhal affections ciliated epithelium from the 
 
THE MICROSCOPE IN DIAGNOSIS. 317 
 
 nasal or respiratory passages may be seen, and perhaps 
 
 molecules of fat, pus-globules, blood, arid u inflammatory 
 
 ::scles." In phthisis the decaying lung may be early 
 
 >y the fibres of elastic tissue from the walls of the 
 
 pulmonary vesicles. The sputa should be first liquefied 
 
 oiling a little while in an equal bulk of caustic soda, 
 
 then allowed to settle in a conical glass, when a small 
 
 quantity may be removed to a glass slide, covered with 
 
 thin glass, and placed under the microscope. 
 
 The occurrence of fungi in sputum is to be expected 
 whenever there is decay. The Leptothrix bwai;.*, one 
 form of , //i, is common on old epithelial seal 
 
 the mouth, and in the latter stages of phthisis the sputa 
 will often show fungi in various forms of development. 
 
 In catarrhal pneumonia we may find fibrinous casts of 
 the alveoli of the lungs and epithelial elements, chloride 
 of sodium, etc. Hydatids are sometimes expectorated in 
 sputum, the appearance of the booklets of the echinococci 
 being quite characteristic. Scales of cholesterin and 
 blood-crystals may also occur, as well as calcareous con- 
 cretions and dark melanotic masses. 
 
 Richardson states that associated matters may indicate 
 the source of blood in sputum. Thus associated salivary 
 corpuscles might show haemorrhage within the mouth, 
 ameboid leucocytes, haemorrhage in the fauces or trachea, 
 starch-granules and particles of food, haematemesis, and 
 coagulated casts, pulmonary haemorrhage. 
 
 VI. VOMITED MATTERS. 
 
 Microscopic examination of vomited matters reveals 
 muscular fibres, starch -granules, oil-globules, and shreds 
 of vegetable tissue, according to the diet of the patient. 
 'air- of margarin, etc., are often seen. Blood, pus, 
 etc., may be recognized if their structure be not destroyed 
 by the digestive fluids. 
 
 ated specimens should be picked out with forceps 
 
318 THE MICROSCOPIST. 
 
 and scissors, or the vomit should stand some time in a 
 conical glass and a little of the deposit removed with a 
 pipette. 
 
 Torula and other forms of fungi are often seen in vom- 
 ited matters. The vomit containing the sarcina ventriculi 
 generally ferments like yeast. 
 
 The color of the " coffee-grounds vomit" is due to dark- 
 brown pigment, probably the altered coloring matter of 
 blood. 
 
 Some specimens of cholera vomit showed numerous 
 flocculi, consisting of epithelium. The clear fluid of py- 
 rosis contains only a little epithelium and a few small oil- 
 globules. The green voniit depending on bile contains 
 cylindrical epithelium from the gall-ducts, scaly epithe- 
 lium, flakes and masses of biliary coloring matter, and fat- 
 globules. 
 
 Dr. Beale records a case of the detachment of flakes of 
 stomach epithelium in a case of scarlet fever. 
 
 Biliary matters, as cholesterin, etc., and even small gall- 
 stones, have been rejected by vomiting. 
 
 VII. INTESTINAL DISCHARGES. 
 
 i 
 
 Microscopists are not unfrequently called upon to ex- 
 amine dubious matters passed from the bowels. Dr. Ben- 
 net describes one case of yellowish pulpy masses passed 
 with the stools as consisting of undigested potato skins, 
 and another made up of a network of confervoid growths 
 developed in the intestinal canal. In one case, seen by 
 the author, tormina, etc., were produced by skins of grapes ; 
 another case exhibited the skin or testa of a large seed, 
 as the tamarind. These instances show the necessity of 
 the observer being familiar with various botanical and 
 histological appearances. 
 
 Blood-globules in feces retain their natural appearance 
 in inverse proportion to the distance of the hsemorrhagic 
 point from the anus, so that quite fresh blood will indicate 
 
THE MICROSCOPE IN DIAGNOSIS. 319 
 
 hemorrhoids, fistula, etc., while more disintegrated disks 
 indicate effusion further up the intestinal tube. 
 
 Mucous casts or coagula of albuminous matters are not 
 very uncommon, either in flakes or tubular casts. The 
 mucus entangles epithelial cells, usually from the large 
 intestine. In typhoid fever crystals of triple phosphates, 
 altered blood, bacteria, and various fungi may be found 
 in tbe fcces, and the stools of cholera patients contain 
 large quantities of cylindrical epithelium, so that the 
 white flocculi are almost entirely composed of it. 
 
 Elastic fibres, exhibiting transverse stride like those of 
 the ligamentum nuchse of the giraffe, are sometimes found 
 arising, in all probability, from incipient decomposition 
 of ingesta. 
 
 Larvae of insects may sometimes be passed alive from 
 the bowels, as well as be ejected from the stomach. The 
 various forms of intestinal worms in their various stages 
 of development may also be met with. In some instances 
 the microscope is needed to distinguish between suspected 
 worms, or portions of worms, and accidental products. 
 Fatty matter in the stools, sometimes semisolid, is usually 
 attributed to derangement of the pancreas. 
 
 VIII. VAGINAL DISCHARGES. 
 
 The diagnostic value of discharges from the vagina, 
 either uterine or vaginal in their origin, has been yet but 
 little studied, and presents a field of special interest in 
 gynaecology. The discharge should be examined while 
 fresh and without the addition of water or other fluids if 
 possible. Should fluid menstrua be really necessary, in- 
 different fluids only should be used. 
 
 The menstrual discharge will be likely to contain young 
 and old epithelial scales and blood-globules. In dysrnenor- 
 rhoea considerable patches of the epithelial membrane 
 desquamate, and even entire casts of the uterus or vagina 
 
320 THE MICROSCOPIST. 
 
 have been separated. The diagnosis between dysmenor- 
 rhoea and abortion may be determined by a microscopic 
 examination of such fragments, since the villi of the 
 chorion can be thus recognized if present. 
 
 In leucorrhcea old epithelial cells, loaded with fat, will 
 be seen, with imperfectly formed epithelium and pus 
 globules. Beale states that the development of pus-cor- 
 puscles from the bioplasts of epithelium may be success- 
 fully studied in leucorrhoeal discharges. Sometimes blood- 
 globules will be seen altered by exosmosis, etc. 
 
 The white gelatinous discharge from the os uteri, often 
 seen in uterine catarrh, consists of mucus with epithelial 
 elements. 
 
 Fibrous, epithelial, and cancerous tumors or ulcers may 
 sometimes be recognized by their microscopic elements, 
 yet it must be remembered that altered epithelium may 
 be readily mistaken for the elements of cancer, etc. 
 
 The Trichomonas vaginalis (Donne) is common in the 
 yellow acrid mucus of vaginal blennorrhoea. It is a round- 
 ish ciliated animalcule, and may be distinguished from 
 ciliated epithelium by the elongation of the anterior end, 
 which is sometimes drawn out into a long filament or 
 flagellum. 
 
 The epithelium from the Fallopian tubes and uterus is 
 columnar and ciliated, while that of the vagina is squa- 
 mous, with large cells. 
 
 Accidental products may also be discharged from the 
 vagina, as well as from other cavities. In one case I found 
 a number of living Crustacea (Gammara-pulex], which oc- 
 casioned great pruritus, but were dislodged by injections 
 of sweet oil. 
 
 Dr. Sims has shown how the microscope may aid in the 
 cure of sterility, since the uterine cervical mucus needs to 
 be slightly alkaline. If habitually acid it destroys the 
 spermatozoa. 
 
THE MICROSCOPE IN .ETIOLOGY. 321 
 
 CHAPTER XV. 
 
 THE MICROSCOPE IN ETIOLOGY. 
 
 THE study of aetiology, or the knowledge of the causes 
 of disease, although so important a branch of practical 
 medicine, needs the careful and united efforts of many 
 observers to be classified and recorded before approaching 
 perfection. Here, also, the microscope will be found an 
 important aid. The numerous external causes of disease, 
 such as physical or organic impurities in the atmosphere, 
 soil, water, and food, vegetable or animal parasites, and 
 "disease germs," with their relation to epidemic or en- 
 demic disorders, all require skilful use of the microscope. 
 
 I. EXAMINATION OF THE AIR. 
 
 The pressure, temperature, moisture, and electricity of 
 the air, all of which are important in considering causes 
 of disease, require other modes of investigation, but the 
 microscope may be reasonably expected to aid in inquiries 
 concerning mechanical, chemical, or organic impurities. 
 
 Many methods have been proposed for collecting mat- 
 ters suspended in the atmosphere. A shallow dish con- 
 taining distilled water, or a clean glass vessel containing 
 ice, so as to condense the atmospheric moisture with its 
 impurities on the outside, and allow it to trickle into a 
 conical receiver, have been used. Glass plates moistened 
 with glycerin and exposed to the air are still better. The 
 aeroscope of Dr. Maddox is a funnel-shaped tube turned 
 to the wind by a vane. The narrow end of the tube is 
 opposite a slide moistened with glycerin. 
 
 Many absurd " discoveries " have been paraded respect- 
 ing matters in air and water, yet careful observation will 
 
 21 
 
322 THE MICROSCOPIST. 
 
 reveal valuable facts. Solid fragments of carbon or silex, 
 etc.. starch grains, filaments of cotton, flax, wool, silk, 
 etc., spores of fungi, animal and vegetable debris, etc., all 
 require considerable familiarity with microscopic objects 
 in general, without which no one should undertake such 
 investigations. 
 
 Minute living particles of bioplasm, either ordinary pus 
 or what Dr. Beale calls "disease germs," should be dili- 
 gently sought for under high objectives. 
 
 Pollen-grains are often found in the air. In Schuylkill 
 County, Pa., in the summer of 1858, after a rain-shower, 
 a yellow scum of pollen covered all the pools, and was 
 traced over a tract of fifty by twelve miles. Showers of 
 "flesh" or "blood" have been described in newspapers, 
 which were probably varieties of Nostoc (page 151), or pig- 
 ment bacteria (page 326). 
 
 The subject of bacteria germs in the air has lately ac- 
 quired great interest from the success of the antiseptic 
 method now generally pursued in large surgical opera- 
 tions, and first introduced by Mr. Lister. This will be 
 considered under the head of disease germs. 
 
 The examination of the breath of men or animals may 
 be made by means of glycerin on glass slides, or by breath- 
 ing through a glass tube containing cotton-wool, which 
 may afterwards be washed with dilute glycerin. Epithe- 
 lial cells, oil-globules, fragments of food, soot, fungi, etc., 
 may thus be detected, or the expired air may be tested 
 for ammonia with hydrochloric acid. 
 
 II. EXAMINATION OF SOIL AND WATER. 
 
 The soil may be examined both chemically and micro- 
 scopically according to the methods given on former pages 
 of this work. The importance of such examination will 
 be plain in many cases of local diseases. It is stated that 
 the mortality caused by murderous epidemics in England 
 
THE MICROSCOPE IN AETIOLOGY. 323 
 
 has been greatly diminished since the systematic building 
 of sewers and the prohibition of pitlike privies in towns. 
 
 Dr. Salisbury's observations on the growth of certain 
 fungi as the cause of malarious fevers, although requiring 
 further confirmation, suggest a very pertinent line of in- 
 quiry. 
 
 Drinking-water may be vitiated by organic matter and 
 its chemical products, as ammonia, chlorine, and the ni- 
 tra'tes. Wagner states that to be drinkable it must not 
 contain in 100,000 parts more than 0.4 parts of nitric acid, 
 0.8 parts of chlorine, and 5 parts of organic matter. Boil- 
 ing does not improve such water. It is generally made 
 impure by sewage, and produces gastric and intestinal 
 diseases, and perhaps typhoid fever. 
 
 III. EXAMINATION OF FOOD, ETC. 
 
 The adulteration of food has long been a question of 
 interest, and has been investigated by a host of observers. 
 Dr. Hassall's voluminous researches, however, leave little 
 to be desired. He states that u in nearly all articles, 
 whether food, drink, or drugs, my opinion is that adul- 
 teration prevails. And many of the substances employed 
 in the adulterating process were not only injurious to 
 health, but even poisonous." Dr. Hassall's work, Food 
 and its Adulterations, should be used by all who inquire 
 into this subject, which is too voluminous to be considered 
 here in detail. Familiarity, however, with the subjects 
 already discussed in this work will qualify the observer 
 for such examinations. Wheat-flour may be examined 
 by adding a little water, and then a few drops of a solu- 
 tion of potash (one part liquor potassse to three of water). 
 Granules of potato-starch swell by this means to three or 
 four times their natural size, while those of wheat-starch 
 are scarcely affected by it. Comparisons of different kinds 
 of starch under the microscope will guide in many other 
 
324 THE MICROSCOPIST. 
 
 investigations. Adulteration of flour with alum, etc., 
 may be detected by dissolving the. alum and recrystalliz- 
 ing under the microscope. 
 
 Coffee 'is adulterated with chiccory, wheat, corn, etc.; 
 tea with foreign leaves, Prussian blue, clay, etc.; choco- 
 late with brickdust, peroxide of iron, animal fat, etc. 
 
 IY. PARASITES. 
 
 Parasites are animal or vegetable organisms which live 
 temporarily or permanently upon or within another or- 
 ganism for their nourishment and development. Casual 
 visitors for the sake of moisture, warmth, or products of 
 decomposition (as many fungi and infusoria) are called 
 pseudo-parasites. Van Beneden distinguishes between 
 messmates which are nourished in common, mutualists 
 which live on and serve each other, and parasites which 
 live at others' expense. 
 
 In this department of science the student will do well 
 to consult Cobbold's magnificent work on Entozoa, and 
 two of the recently published international scientific series 
 of books, viz., Fungi, by Cooke and Berkely, and Animal 
 Messmates and Parasites, by Van Beneden. 
 
 The plan of Wagner, in his Manual of General Pathol- 
 ogy, is followed in the present outline, so far as classifica- 
 tion is concerned. 
 
 I. VEGETABLE PARASITES OR EPIPHYTES. 
 I. FUNGI. 
 
 The general character and development of fungi have 
 been described at page 136. The subject of polymor- 
 phism also has been referred to as indicating the uncer- 
 tainty of distinguishing genera and species. Cooke re- 
 minds us, however, that polymorphism can only be based 
 upon actual organic continuity, the observance of which 
 in such minute organisms is necessarily difficult. 
 
THE MICROSCOPE IN AETIOLOGY. 325 
 
 A. DUST OR GERM FUNGI, CONIO OR GYMNOMYCETES. 
 
 1. Mycoderma (Cryptococcus). The beer-yeast (Micro- 
 coccus, or Torula cerevisice) consists of round or oval color- 
 less cells containing one, and sometimes two bright nuclei 
 resembling oil-globules. New cells arise from these by 
 budding. No proper filament or mycelium is formed. 
 
 The milk-yeast (Oidium ladis) can grow fungus-like if 
 submerged, while on the surface is a mycelium of articu- 
 lated filaments from which shoots grow up, whose cells 
 separate easily. 
 
 Schwann, Pasteur, etc., consider the, yeast-fungi as or- 
 ganisms produced by specific germs, w^hile others regard 
 them as spores, which in the atmosphere fructify in other 
 forms. 
 
 B. FILAMENTOUS FUNGI, HYPHOMYCETES. 
 
 The mycelia of these are lengthened tubular cells, often 
 branching. The spores originate within or at the end of 
 filaments. Here belong the fungus of the musoardine of 
 the silkworm (Botrytis bassiana), the potato disease (Fusi- 
 porium solani), the grape disease (Oidium tuckerii), mould, 
 and the fungi occurring in diseases of skin and mucous 
 membranes. 
 
 1. Penicillium glaucum, common mould or pencil mould, 
 forms most of the mould occurring upon vegetable de- 
 composing substances. The fruit-bearers rise from a 
 branched colorless mycelium. The points are tufted and 
 bear spherical conidia. 
 
 2. Aspergillus glaucus, or green mould, is often found 
 with the foregoing. The fruit-filaments expand into club- 
 shaped basidia. The spores are greenish. 
 
 3. Mucor mucedo and Mucor racemosus are found on 
 excrement and old articles of food. The bladder-like 
 swollen fruit-hyphen (columella) rises from a branched 
 
326 THE MICROSCOPIST. 
 
 filamentous mycelium, which becomes septate with age. 
 The spores are set free by breaking of the wall of the 
 sporangium. 
 
 C. CLEFT FUNGI, SCHIZOMYCETES (bacterium, micrococcus). 
 
 The term schizomycetes is given from the great fra- 
 gility of the formation. They are cells without chloro- 
 phyll, of various forms, which increase exclusively by 
 transverse division. The cell-membrane is not destroyed 
 by potassa, nor by acids, and resists decomposition for a 
 lono; time. 
 
 O 
 
 1st Group. Spherobacteria. Globular bacteria (Pas- 
 teur's Monas or Mycoderma. Ehrenberg's Monas corpus- 
 culum and prodigiosa. Hallier's Micrococcus}. 
 
 Spherical or oval cells, without granular contents, pos- 
 sessing a double contour, and becoming moniliform by 
 division. Often difficult to distinguish from granular 
 detritus. 
 
 1st Genus. Micrococcus (Cohn). Bells colorless or nearly 
 so, very small, united into short moniliform filaments of 
 two or more members (mycrothrix, torida-forms], or into 
 many-celled families, balls, or colonies, or into mucous 
 masses (zoogloa-forms, m.ycoderma-forms). No movement. 
 
 (1.) Pigment bacteria. Appearing in colored jellylike 
 masses. 
 
 a. Coloring matter, insoluble, red and yellow. 
 
 1. Micrococcus Prodigiosus (Palmdla prod.). Cause of 
 the seeming blood-spots which sometimes appear during 
 moisture on wafers, bread, potatoes, etc. 
 
 2. M. luteus. 
 
 b. Coloring matter, soluble. M. aurantiaceus, chlorinus, 
 etc. 
 
 (2.) Zymogenic globular bacteria. 
 
 3. Microccocus Urea. Ferment of urine. 
 
THE MICROSCOPE IN ETIOLOGY. 327 
 
 (3.) Pathogenic globular bacteria. " Ferments of con- 
 tagion." 
 
 4. M. vaccince. 
 
 5. M. diphthericus 
 
 6. M. Septicus. Some deem it the cause of pyaemia. 
 
 7. M. Bombycis. A destructive epidemic among silk- 
 worms of Southern France, but different from muscardine 
 and gattine. 
 
 2d Group. Microbacteria. Rodlike bacteria, resemble 
 globular bacteria in the small size of cells and their tem- 
 porary union into mucous masses, but are distinguished 
 by their short cylindrical forms and spontaneous move- 
 ments. 
 
 2d Genus. Bacterium. 
 
 1. Bacterium Termo. Cells short, cylindrical, oblong. 
 They turn on their axis and swim forward, then return a 
 little or travel in curved lines as if trembling, or spring- 
 ing forward and then becoming quiet. 
 
 2. B. Lineola. Cells cylindrical, broad, straight, with 
 refractive soft contents, and fatlike granules. Single or 
 in pairs. 
 
 3d Group. Desmobacteria Filamentous B. Filaments 
 not constricted at the joints, but throughout cylindrical 
 (leptothrix filaments). May form swarms but not zoogloa- 
 form masses. 
 
 1st Genus. Bacillus. Filaments straight. 
 
 1. B. Subtilis. Butyric acid ferment. 
 
 2. B. Anthracis. Bacteridia of gangrene of the spleen. 
 
 3. B. Ulna. 
 
 2d Genus. Vibrio. Filaments wavy, thick, with single 
 curve ( V. rugla\ or thin, with many curves ( V. serpens). 
 
 4th Group. Spirohacteria. Screw bacteria. Distin- 
 guished from vibrio by the closer regular permanent spiral 
 of the lilarnent. 
 
 1st Genus. Spirochazta. 
 
 1. S. Plicatilis. In tartar from the teeth. 
 
328 THE MICROSCOPTST. 
 
 2d Genus. Spirillum. Shorter and more distant spiral. 
 
 5th Group. 
 
 1st Genus. Leptothrix. 
 
 1 L. BuccaHs. Long, brittle, slender filaments, divided 
 by partition-walls. Occurs on products of decomposition 
 within the mouth ; papillae of tongue, tartar, etc. Also 
 in the intestine, vagina, etc. It is thought by some to 
 produce caries of the teeth. 
 
 2d Genus. Sarcina. 
 
 1. S. Ventriculi. Four-fold flat cubical cells, generally 
 with nuclei. Occurs in vomited fluid, urine, etc. 
 
 In addition to the above (provisional) arrangement, 
 "Wagner classifies vegetable parasites with respect to their 
 pathological relations as follows : 
 
 I. MOULD DISEASES. 
 
 These are conditional upon the above-mentioned mould 
 fungi. They occur chiefly upon parts affected with ne- 
 crosis or other lesions, particularly ulcers of the skin and 
 mucous membranes. On free surfaces they present an 
 appearance resembling mould. Perhaps in this connec- 
 tion belongs the foot-fungus, or Mycetoma Carterii, which 
 is endemic in India. 
 
 II. FUNGI OF TRUE PARASITIC DISEASES OF THE SKIN 
 AND MUCOUS MEMBRANES. 
 
 1. Tricophyton Tonsurans. This consists of round trans- 
 parent spores, or spore-rows. They develop in the roots 
 of the hair and pass into the shaft, so that the latter is 
 destroyed and breaks off. It occurs also in the sheaths 
 of the hair-roots and surrounding epidermis, seldom in 
 the nails. It causes several diseases, especially of the 
 scalp and beard, as herpes tonsurans, porrigo scutellate, men- 
 
THE MICROSCOPE IN AETIOLOGY. 329 
 
 tagra (sycosis), eczema marginatum, etc. It is thought by 
 some to proceed from aspergillus. 
 
 In examining hair, skin, etc., for fungi, the specimens 
 should be soaked in liquor potassse long enough to become 
 transparent. 
 
 2. Achorion Schonleinii Favus Fungus. Mycelia com- 
 posed of small, simple, or branching tubes divided by par- 
 titions. Spores round or oval, sometimes grouped in 
 masses. The cause of tinea favosa of the scalp. 
 
 3. Microsporon Audouinii. Undulating forked filaments 
 on which spores are directly placed. Found round the 
 shaft of the hair after its exit from the follicle, so thick 
 that the hair breaks off and causes baldness. Porrigo de- 
 ealvans. 
 
 4. Microsporon Furfur. Masses of large, round, mostly 
 nucleated spores, and long or branched cells. Sometimes 
 with numerous broad filaments. Developed in the horny 
 layer of the epidermis, commonly round the opening of 
 hair follicles of the breast and back, producing yellowish 
 discoloration and branlike scales, with itching, Pityria- 
 
 ' sis versicolor. 
 
 5. Oidium Albicans Thrush Fungus Tubular fila- 
 ments, branching stems, and minute spores. Ends of fila- 
 ments lost in masses of spores, with a large, often divided 
 spore-cell. Found in aphthae of the mouth, tongue, throat, 
 vagina, etc. 
 
 III. FUNGI AS EXCITORS OF FERMENTATION AND PUTRE- 
 FACTION AND CAUSES OF DISEASE. 
 
 At page 137 the distinction between diseased conditions 
 which invite fungi and the effects produced by fungi 
 themselves was stated. That fungi are the cause of spe- 
 cific fermentations (acetic, alcoholic, lactic, butyric, etc.), 
 is rendered very probable by modern researches, especially 
 those of Pasteur. In decay, or oxidation, and in putre- 
 
330 THE MICROSCOPIST. 
 
 faction of organic bodies, fungi are important agents. 
 In the former vibrios are found, and in the latter monads 
 and bacteria. Decay is arrested if access of fungus germs 
 is prevented. Putrefaction is as dependent on bacteria as 
 the fermentation of non-nitrogenous bodies upon yeast- 
 fungi. 
 
 Many acute infectious diseases are considered to pro- 
 ceed from fungi, although the reasons for such an opinion 
 are chiefly theoretical, arising from the presence of fungi 
 in those diseases. Such are diphtheria, pyaemia, puer- 
 peral fever, small-pox, etc. Many experiments have been 
 made, by inoculation, etc., but thus far with little results. 
 Observers differ greatly concerning the same disease, the 
 specific fungus of one being disavowed by another. Still, 
 much light may be expected respecting aetiology from ob- 
 servations of this kind. 
 
 II. ANIMAL PARASITES. 
 
 These inhabit either the external surface (epizoa) or 
 internal organs (entozoa). 
 
 I. PROTOZOA. 
 
 GREGARINIM. See page 180. Gregarinidce are para- 
 sitic animals, generally regarded as the lowest of the pro- 
 tozoa, although this opinion is doubtful. They usually 
 consist of a single cell, with an illy-defined membrane 
 filled with granular and fatty sarcode, with nucleus and 
 nucleolus. They are developed much like protophytes, 
 page 140. The gregarina becomes motionless, globular, 
 and enc3'Sted. The nucleus then disappears and the sar- 
 code breaks up into little masses which become pointed 
 at each end (pseudo-navicellse). These masses escape as 
 amoeba, page 121, and develop new gregarince. 
 
 Globular psorospermice, as they are called, have been 
 
THE MICROSCOPE IN ETIOLOGY. 331 
 
 found in the liver and intestines of rabbits and of man, 
 and are regarded as the resting stage of gregarince. 
 
 INFUSORIA. Family, Heterotricha. Body covered with 
 cilia, often in longitudinal rows. Stronger cilia about 
 the mouth. 
 
 Balantidium Boli. A common parasite in the rectum 
 of hogs. Found sometimes in human intestine. 
 
 FLAGELLATE. Infusorial organisms with lashlike cilia. 
 Family, Monadina. Round or oval. Transparent. A 
 single or few whiplike hairs on anterior extremity. 
 
 Cercomonas. With caudal filament and generally a 
 single thin and long lash. 
 
 C. Intestinal is. Found in the stools of cholera and 
 typhoid fever, and on catarrhal mucous membrane of 
 children. 
 
 C. Urinarius. Urine of cholera and in alkaline albu- 
 minous urine. 
 
 C. Saltans. On the dirty surface of ulcers. 
 
 Trichomonas. With two or three short cilia near the 
 anterior lash. 
 
 T. Vaginalis. In the yellow acrid mucus of vaginal 
 blennorrhoaa. 
 
 II. YERMES (Worms). 
 
 1st Class. Platodes Platyelmia. Flat worms. Bodies 
 flat, appendages, when present, of suckers and hooks. 
 Generally hermaphrodite. Many without mouth or in- 
 testine, nourished by absorption. 
 
 1st Order. Cestodes. Tapeworms. Long, articulated, 
 flat, without mouth or alimentary canal. Prehensile or- 
 gans anterior. The anterior part or head is small and 
 somewhat globular. The neck is thinner. The joints 
 lengthen and broaden in continuous succession until they 
 reach their greatest circumference at the posterior ex- 
 tremity, where they may separate and live independently 
 
332 THE MICROSCOPIST. 
 
 as proglottides. The cellular connective parenchyma in- 
 closes in its peripher} T . especially on the head, small chalky 
 concretions, in all parts the ramifications of a water-vas- 
 cular system, and in the central parts the sexual organs. 
 Each segment has its special male and female organs of 
 generation. 
 
 Human tapeworms exhibit a complicated metamorpho- 
 sis connected with alternate generation. Generally the 
 ova with the proglottides pass from the intestines and 
 are conveyed with food into the stomach of an animal. 
 The embryos become free in the stomach, and by their 
 movable booklets bore their way into the bloodvessels 
 and are deposited in various organs, as the liver, muscles, 
 brain, etc. Here they become encapsulated and grow into 
 larger vesicles, each of which is a cystworm. From its 
 covering one (cysticercus) or several (echinococcus) nodu- 
 lar depressions grow into the interior, on the bottom of 
 which is the armament of the tapeworm's head, in form 
 of suckers and hooks. The transportation into the human 
 stomach is effected by means of food, especially measled 
 meat. The cyst is digested and the head of the tapeworm 
 set free as a Scolex. This enters the small intestine, be- 
 comes fixed, and develops by gradual formation of seg- 
 ments the tapeworm body. 
 
 Family. Tceniadce. Head pear-shaped or conoidal, with 
 four round suckers. A rostellum or wreath of hooks be- 
 tween the suckers or anterior part of head. Proglottides 
 distinctly separate and generally longer than broad. 
 
 A. Vesicular tapeworms, Cysticcz. Head rarely un- 
 armed (T. mediocanellata\ generally w r ith rostellum and 
 hooks. Middle stern of uterus gives off ramifying side- 
 branches. Openings of sexual apparatus on the border, 
 alternate on each side. 
 
 a. Vesicular tapeworms, whose heads are formed in 
 the embryonal state. 
 
 1. Tcenia Solium. Single, or several together in small 
 
THE MICROSCOPE IN .ETIOLOGY. 333 
 
 intestine. Develops to from two to three meters long, and 
 its proglottides ten mm. long and six mm. broad. Head 
 the size of a pin, globular, with tolerably prominent suck- 
 ers. Filamentous neck, almost an inch long The cyst worm 
 (Cysticercus cellulosce) of this species has a preference for 
 the muscles of the hog, but is found in other animals and 
 in man. 
 
 2. Tcenia Mediocanellata. Larger than the T. solium. 
 Head without a circle of hooks and rostellum, but with 
 powerful suckers. The cystworm inhabits the muscles of 
 cattle, but has not been found in man. 
 
 3. T. Acanthotrias. The vesicle only is known. Found 
 in muscles, subcutaneous tissue, and brain of man. Hook 
 apparatus a triple circle of slender claws. 
 
 4. T. Marginata. Mature tsenise are like T. solium, but 
 found in the dog and wolf. The larva abides in the 
 omentum or liver of ruminants and swine, and sometimes 
 of man. One extremity of the vesicle is drawn out in a 
 necklike process, which contains the tapeworm. 
 
 b. Cyst tapeworms, whose heads bud from the embry- 
 onic capsules of the inner surface of the vesicle. 
 
 5. Tcenia echinococcus consists of only three or four seg- 
 ments, the last of which exceeds in bulk all the others. 
 It is three to four mm. long, and its thirty or forty hook- 
 lets are on a prominent rostellum. It lives in the intes- 
 tine of the dog. The young state of this Tsenia (echino- 
 coccus) is an almost motionless vesicle on the inner sur- 
 face, of which numerous little heads bud in vesicles the 
 size of a millet-seed. These are sometimes compound 
 (daughter, granddaughter vesicles\ inclosed one within the 
 other. In this form they are found in man and cattle 
 (especially in the liver). Other animals harbor generally 
 single vesicles. 
 
 B. Common tapeworms, Cystoidece. They represent no 
 peculiar larv?e. Their larvae occur only in cold-blooded 
 animals or invertebrates. Thus the cysticercoid of T. 
 
334 THE MICROSCOPIST. 
 
 elliptica or cucumerina of the dog live in the lice which 
 infest dogs, and the dogs are infected by eating these lice. 
 Clinically, they are less important than cyst tapeworms. 
 Head small and hook apparatus imperfect. 
 
 a. Head prominence with a single circle of small hooks. 
 
 6. Tcenia Nana. Small. Anteriorly filamentous, but 
 larger near the middle. Once found in the duodenum of 
 a boy. 
 
 7. T. Flaw Punctata. 33 cent. long. The anterior half 
 of immature joints 0.2 to 0.5 mm. long and 1 mm. broad, 
 which show behind the middle a large yellow spot. The 
 receptaculum filled with sperm. Head unknown. 
 
 b. Papilla with multiple circle of hooks. 
 
 8. T. Elliptica. Usually in dogs and cats. 
 
 Family Bothriocephalidce. Head flattened. Two deep 
 fissure-like suckers. Articulations imperfectly marked. 
 
 9. Bothriocephalus Latus. The largest human tape- 
 worm. Sometimes 5 to 8 meters long and from 3000 to 
 4000 short and broad joints, seldom more than 3.5 mm. 
 long, but 10 or 12 mm. broad. The last joints are nearly 
 square. Anterior end threadlike. Proglottides pass away 
 in lengths (from 2 to 4 feet). Ova oval, with transparent 
 shells, and a lid at one end through which the embryo 
 slips into the water. The six-hooked embryo is developed 
 several months after the ova are passed. 
 
 10. B. Cordatus. Smaller than B. latus. Head short 
 and broad, heart-shaped. 
 
 2d Order. Trematodes. Suckerworms. Parasitic solitary 
 flat worms, with inarticulate leaf-shaped bodies ; with 
 mouth and bifurcated intestinal canal, without anus, 
 with abdominal prehensile apparatus. Male and female 
 organs mostly in the same individual. The distomata 
 go through a complicated alternate generation and 
 metamorphosis. The embryos escape from the ova 
 into water and seek a new animal habitat, mostly 
 snails. Here they develop into cyst-germs, which are the 
 parents of the Cercarice, which have a rudder-like tail and 
 
THE MICROSCOPE IN AETIOLOGY. 335 
 
 move freely in the water. These enter a new aquatic 
 animal, snail, worm, crab, or fish, pierce into the tissues 
 and form a cyst. Thus the young, encysted, sexless disto- 
 mata arise from the Cercarise, the former received with 
 the flesh of their supporters into the stomach, and thence 
 freed from their cyst they enter other organs of another 
 animal, where they become sexually mature. 
 
 Gen. Distomum. Two suckers on the anterior part. 
 Genital pores near the abdominal sucker. 
 
 a. Body broad and leaf-shaped. 
 
 11. Distomum Hepaticum. Liver-fluke. The Cercarise 
 are probably encapsuled in fresh-water snails, and eaten 
 by sheep infect them. The perfect D. hepaticum inhabits 
 numerous herbivorous mammals and occurs in man. 
 
 b. Body more regular in form, without branched in- 
 testinal canal. 
 
 12. D. crassum. 
 
 13. D. Lanceolatum. Both extremities pointed. Asso- 
 ciated with D. hepaticum in the bile-ducts. 
 
 14. D. Ophthalmobium. Once found in the crystalline 
 lens. 
 
 15. D. heterophyes. 
 
 c. "\Vith separate sexual apparatus. Body long and 
 slender. Female almost cylindrical. 
 
 16. D. Hcematobium. Oral and abdominal suckers equal 
 in size. Color white. Is frequent in Egypt, in the veins 
 as well as intestinal canal and bladder. Feeds on the 
 blood. 
 
 Gen. Monostomum. Has no abdominal sucker. 
 
 17. Monostomum Cutis. Found once in the lens. 
 
 2d Class. Rematelmia. Round\vorms. Bodies rounded, 
 pouched, or filamentous, without rings or segments. 
 Sometimes with papillae or hooks on anterior pole Sexes 
 distinct. 
 
 1st Order. Acanthocephali Vertex bearing hooks. No 
 mouth or intestine. 
 
336 THE MICROSCOPIST. 
 
 18. Echinorrhynchus. Inhabits the intestine of several 
 vertebrates. One found in a leucaemic child. 
 
 2d Order. Nematode*. Threadworms. Bodies round, 
 threadlike, with mouth and intestine. Armament, when 
 present, of papillae or spikelets and hooks within the 
 mouth. Development by single metamorphosis, yet many 
 young forms have an abode altogether different from that 
 of their parents, and often the young and sexually mature 
 inhabit different organs or different animals. Some live 
 parasitically in plants. 
 
 1st Sub- order. Strong yloidce. Nernatodes with anus. 
 
 1st Family. Ascarides. Mouth with three lips or pa- 
 pillae. Sometimes teeth in the throat. Most lay hard- 
 shelled eggs. 
 
 19. Ascaris Lumbricoides. Roundworm. Cylindrical 
 body. Male 250 mrn. by 3 mm. Female 400 mm. by 5.5 
 mm. Tail of male conical and hooked. 
 
 20. A. Mysto.x. Smaller than the preceding. Identical 
 with the common round worm of cats. 
 
 21. Oxyuris Vermicidaris. Threadworm. Body fila- 
 mentous, white. Three lips on the head. Inhabit chiefly 
 the rectum and large intestine, but may wander to vagina. 
 
 2d Family. Strong yloidce. Mouth generally armed with 
 a horny surface or hooks. 
 
 22. Strongylus Gigas. Long red worm. Viviparous. 
 In the pelvis of the human kidney. 
 
 23. S. Longevaginatus. Filamentous, white. 
 
 24. 8. Armatus. Cause of the so-called colic of the 
 horse, which is really aneurism of the intestinal arteries. 
 
 25. S. Duodenalis. Body cylindrical. Mouth wide, 
 with two claw-shaped hooks. In Italy and Egypt found 
 in the intestines by thousands. Gives rise to anaemia, etc. 
 
 3d Family. Trichotrachelidce. Moderately large, longi- 
 tudinally striated worms. 
 
 26. Trichocephalas Dispar. Long threadworm. Body 
 short, 2 cent, long by 1 mm. thick, with filiform neck, 
 
THE MICROSCOPE IN .ETIOLOGY. 337 
 
 20 to 25 mm. long, and head; in the male spiral, in the 
 female straight. Generally found in the colon of children 
 or adults. 
 
 27. Trichina Spiralis.^On the second day after eating 
 raw flesh containing trichinae, and after digestion of the 
 inclosing capsule, the worm is sexually mature Copula- 
 tion occurs, and on the sixth day after the females bring 
 forth each about 1000 filamentous embryos. These pierce 
 the intestinal wall and wander through the tissues to the 
 voluntary muscles, where they coil up spirally and be- 
 come encysted. The cysts may become hard and even 
 calcify. In this state they may remain for years capable 
 of development. The hog is considered the original 
 bearer of trichinae, whence they have infected other ani- 
 mals. 
 
 4. Family. Filaridce. Long filamentous body. 
 
 28. Filaria Medicensis. Threadworm. Guinea worm. 
 Inhabits the subcutaneous tissue of the foot. Found only 
 in tropical countries. 
 
 3d Class. Annelida. Ringed worms. Cylindrical or 
 flattened. Segmented body with brain, cesophageal ring, 
 chain of abdominal ganglia and bloodvessels. 
 
 Order Hirudinis. Leech. Body with narrow rings 
 and terminal disk. Xo feet. Hermaphrodite. 
 
 Sub-order G?iathobdellce. Gill-leach. Throat with three 
 often clentated gills. A sort of oval sucker disk in front 
 of the mouth. Blood mostly red. 
 
 29. Hirudo Medicmalis.zQ to 90 fine teeth on the 
 free border of the gills. Is three years in arriving to 
 sexual maturity. 
 
 III. ARTHROPODA. 
 
 Animals laterally symmetrical. Bodies segmented. 
 Limbs articulate. Brain and abdominal ganglia present. 
 Propagation generally sexual. 
 
 22 
 
338 THE MICROSCOPIST. 
 
 Class Arachnids. Air-breathing. Head and thorax 
 blended. No feelers. Two pairs of jaws and legs. Ab- 
 domen without members. Sexes distinct. 
 
 Order Linguatulidce (Pentastomidse). Worm-shaped, 
 ringed. Mouth rounded, with horny border. Four legs, 
 hooklike and sheathed. Surface hard and pierced by 
 stigmata. Metamorphosis complete. 
 
 30. Pentastomum Tcenioides. Inhabits the nasal cavities 
 of the dog and wolf. The larva have been found in man. 
 
 31. Pentastomum Denticulatum. Encapsuled, curved, 
 calcified. On the surface of the liver, etc. 
 
 Order Acarince. Mites. Body compact, inarticulate. 
 Mouth for biting, sucking, or stinging. Respiration by 
 tracheae. 
 
 Family Dermatophili. Hair-follicle mite. Elongated. 
 Worm-shaped, fringed abdomen. Suckers and stiletto- 
 shaped jaws. Four pairs of short bipartite feet. 
 
 32. Acarus Folliculorum (Dermodex Folliculorum). 
 Found often in ear-wax and sebaceous glands of face. 
 
 Family Acaridce. Mites. Microscopic, soft-skinned. 
 Legs short, with disks for prehension. 
 
 33. Acarus, or Sarcoptes Scabiei.- Itch-mite. Body 
 round, arched, with transverse strise covered w T ith spines 
 and bristles. Young have but one pair of feet. 
 
 Family Ixodce. Ticks. Larger, blood-sucking mites, 
 with firm back- shield and dentated mandibles. Live on 
 plants, and occasionally on man. The female inserts its 
 proboscis, and fills itself w T ith blood, causing pain and 
 suppuration. There are several species. 
 
 Family Trombididce. Running mites. Body brightly 
 colored, covered with hair. They live on plants, etc., but 
 sometimes on man. The Leptus autumnalis, gooseberry 
 or harvest mite, is often troublesome in summer. 
 
 Class Hexapoda. Insects. 
 
 Order Rhynchota. 
 
 Sub-order Aptera. Wingless insects, with short, turned- 
 
THE MICROSCOPE IN .ETIOLOGY. 339 
 
 in, fleshy beak, and piercing bristles, or with rudimentary 
 biting mouth. Body has usually nine articulations. 
 
 Pediculus Capitis. Head-louse. 
 
 P. Pubis or Phthirius Inguinalis. Crabs. 
 
 P. Vestimenti. Clothes-louse. 
 
 Sub-order Hemiptera. 
 
 Cimex Lectularius. Bed-bugs. 
 
 Order Diptera. Insects witli mouths for piercing or 
 sucking. Inarticulate thorax, with cuticular anterior 
 wings. Swing-bats for posterior wings. Complete meta- 
 morphosis. 
 
 Palex Irritans. Flea. 
 
 Pulex or Dermatopkilus Penetrans. Sand-flea. Native 
 of South America. Breeds under the cutis, and the ova 
 develop in the sand. 
 
 (Estrus Homini. Gad-fly. May deposit ova in skin of 
 man, producing boils. 
 
 Musca Vomitoria. Large, blue-bottle fly. 
 
 31. Sarcophaga. Common flesh-fly. 
 
 M. Domestica. House-fly. 
 
 All may deposit ova or fully formed larva in cavities 
 and wounds. 
 
 Y. DISEASE GERMS. 
 
 The germ-theory of disease ascribes disease, particularly 
 infectious disease, to the introduction of minute parasitic 
 organisms into the tissues of the body, and their subse- 
 quent multiplication there. Many of the early natural- 
 ists entertained substantially this view, as Yallisneri, 
 Reaumur, and Linnaeus. It was considered, however, but 
 a mere hypothesis, until recent microscopic observations 
 have revived an interest in this direction. Liebermeister, 
 in his recent monograph on typhoid fever, says, " Within 
 the last ten years a great revolution has taken place with 
 regard to the popular signification of a contagiinn vivum. 
 Xew investigations on the appearance, mode of propaga- 
 
340 THE MICROSCOPIST. 
 
 tion, and the significance of the low organisms, new facts 
 in regard to the extension of national diseases, and also a 
 number of quite positive discoveries by numerous investi- 
 gators, have removed the old opposition to the theory, or 
 even been the means of furnishing definite proof of its 
 correctness." This quotation expresses the most san- 
 guine views of the adherents of this theory. 
 
 We have already referred to the connection of mould 
 and yeast fungi with the process of fermentation, and it 
 is quite possible that the introduction of such germs into 
 the body may produce slight irritations and even inflam- 
 mations from the increase and multiplication of the fungi, 
 and the chemical changes induced by them. We have 
 also seen that fungi are causes of putrefaction as well as 
 of fermentation in organic bodies. Yet the diseases of 
 the human body, in which fungi have been proved to be 
 real causes, are but few. Among vegetable diseases 
 caused by fungi are the rust, smut, etc., of our grains, the 
 " vine disease," " potato disease," etc. Among animal 
 diseases of this kind are some affections of caterpillars, 
 flies, etc., and gangrene of the spleen in mammals. In 
 splenic gangrene, however, as well as in mycosis intesti- 
 nalis, pyaemia, diphtheria, etc., in which fungi occur, the 
 bacteria may be merely the carriers of the disease, or may 
 develop because of special pabulum furnished by the dis- 
 eased structure which is not present in the normal state. 
 
 Another theory of disease-germs has been published by 
 Dr. Beale, which regards them as minute masses of de- 
 praved bioplasm, originated probably in man's own body, 
 or in the bodies of some of the animals domesticated by 
 man. 
 
 Both theories may be true in reference to the cases to 
 which they are applicable. They do not even necessarily 
 exclude each other. Each kind of disease-germ, bioplastic 
 or fungoid, may have a range of action peculiarly its own. 
 
 Dr. Beale's views seem to apply to a much wider field 
 
THE MICROSCOPE IN ETIOLOGY. 341 
 
 of research than the other, and are therefore given here 
 in abridged form. 
 
 Dr. Beale objects to calling disease-germs parasites, 
 since parasites are organisms themselves, and not mere 
 particles of living matter. He freely admits the great 
 variety and rapid growth of microscopic fungi and algse, 
 and the readiness with which they may enter and traverse 
 the textures of the body, but considers them to be but 
 seldom the cause of disease. He says, " In every part of 
 the body of man and the higher animals, and probably 
 from the earliest age, and in all states of health, vegetable 
 germs do exist. These germs are in a dormant or quies- 
 cent state, but may become active and undergo develop- 
 ment during life should the conditions favorable to their , 
 increase be manifested. There is not a tissue in which 
 these germs do not exist, nor is the blood of man free 
 from them. They are found not only in the interstices of 
 tissues but they invade the elementary parts themselves. 
 Multitudes infest the old epithelial cells of many of the 
 internal surfaces, and grow and flourish in the very sub- 
 stance of the formed material of the cell itself. In many 
 very different forms of disease these germs of bacteria, 
 and probably of many fungi, are to be discovered in the 
 fluids of the body, but the evidence yet adduced does not 
 establish any connection between the germs and the mor- 
 bid process. The diseases known to depend upon the 
 growth and development of vegetable organisms are local 
 affections, and the structure of the organism can be made 
 out without difficulty, but contagions are general affec- 
 tions, and no such success attends our efforts to prove 
 that vegetable organisms are the active agents. In fact, 
 the fungi which commonly grow on the surface and in 
 other parts of the body do not produce disease. The germs 
 of fungi may remain perfectly passive in healthy textures, 
 growing and multiplying only in those which have already 
 deteriorated in consequence of disease or old age." 
 
342 THE MICROSCOPIST. 
 
 We have already considered Dr. Beale's views respect- 
 ing bioplasm page 118 as the forming material of the 
 tissues. At page 246 we have also referred to his doctrine 
 of inflammation, etc. These views will prepare us to 
 understand the theory of " disease-germs," considered as 
 degraded particles of bioplasm. " Degradation in power 
 is commonly associated with increased rate of growth, and 
 with remarkable vitality. The actively living degraded 
 bioplasm may retain its vitality although removed from 
 the living body, and it may grow and at length destroy 
 other living organisms to which it gains access." Animal 
 fluids and secretions, normal as well as those known to 
 have contagious properties, contain minute particles of 
 bioplasm, which are sometimes so small as to require the 
 highest microscopic powers to render them visible, yet 
 they are capable of growth and multiplication to a vast 
 extent, so that a minute particle of vaccine or other lymph 
 may originate important changes in a large number of 
 persons. 
 
 The virulent poison of dissection-wounds cannot be as- 
 cribed to vegetable germs, since it is most virulent shortly 
 after death of the subject of dissection, and when putre- 
 factive decomposition has taken place, and bacteria swarm, 
 the real contagious virus is dead. Such is the vitality, 
 however, of some forms of degraded bioplasm, that they 
 will not only multiply on mucous surfaces, but live long 
 after their removal, as in purulent ophthalmia, gonor- 
 rhceal pus, etc., so that they may be transported in vari- 
 ous ways from one place to another and still retain their 
 multiplying power. A very small portion of blood, serum, 
 or of the tissues of an affected animal is sufficient to 
 propagate cattle-plague. Even the breath of the diseased 
 organism contains numerous virulent particles. There is 
 reason, also, for thinking that a single epithelial cell may 
 contain multitudes of active particles in the case of syphi- 
 litic poison which may remain dormant, perhaps for years, 
 
THE MICROSCOPE IN J5TIOLOGY. 343 
 
 or may from time to time give rise to changes peculiar to 
 it. Particles of living tubercle may be so minute as to be 
 carried in the atmosphere, although tubercle is not emi- 
 nently contagious. As to cancer germs, many circum- 
 stances render it improbable that they can be transmitted, 
 so that living disease germs differ remarkably in vital 
 power as well as forms of activity. Yet they resemble 
 each other in general appearance. Neither by its form, 
 chemical composition, or other demonstrable properties, 
 can the vaccine germ be distinguished from the small-pox 
 germ, or the pus germ from either. All are like the 
 minute particles of bioplasm of the blood, from which 
 they differ so remarkably in power. Of the conditions 
 under which these germs are produced, and of the manner 
 in which the rapidly multiplying matter acquires its new 
 and marvellous specific powers, we have very much yet 
 to learn. For the manner of detecting these germs in the 
 air, etc., see the former part of the present chapter. Mr. 
 Lister's excellent plan for the antiseptic treatment of 
 wounds, and especially the results of carbolic acid spray 
 in surgical operations, together with many posititive ex- 
 periments, show that carbolic acid has a powerful action 
 in arresting vital phenomena or destroying bioplasm. In 
 its presence embryonic life is impossible ; under its power- 
 ful influence all minute forms of life perish. Dr. Beale, 
 also, refers to the effects of carbolic acid, and sulpho-car- 
 bolates administered internally, in checking the too rapid 
 growth of bioplasm in the blood and tissues, as well as to 
 the importance of disinfectants, or the destruction of dis- 
 ease germs in the air, sewage, etc. 
 
 Among the strongest objections to the theory of fungoid 
 disease germs are those given by Dr. Bastian (a strong 
 supporter of spontaneous generation), that the theory de- 
 mands a belief in the existence of organisms never known 
 in their mature state, and whose existence is not demon- 
 strated but merely presumed ; that such germs have been 
 
344 THE MICROSCOPIST. 
 
 experimentally shown to be incapable of producing the 
 diseases they are assumed to cause; and that feeding on 
 putrid flesh, swarming with bacteria, as the Kalmucks do 
 habitually, produces no injurious consequences. These 
 objections do not apply to the theory of disease germs 
 advanced by Dr. Beale, while it will be found to accord 
 with the most careful and thorough investigations in 
 biology and pathology. Yet Beale's views have received 
 less attention than they deserve, perhaps because of his 
 pronounced antagonism to the evolutional philosophy, 
 which is so commonly taught under the guise of natural 
 science. 
 
APPENDIX. 845 
 
 APPENDIX. 
 
 RECENT ADDITIONS TO THE MICROSCOPE AND MICROSCOPIC 
 TECHNOLOGY. 
 
 OPTICIANS and microscopists strive continually after 
 absolute perfection in their instrumental means of re- 
 search, so that every little while some new piece of ap- 
 paratus or new method is announced. The most impor- 
 tant recent additions are named here. 
 
 IMPROVEMENTS IN MECHANISM. 
 
 Some notable improvements have been added to first- 
 class instruments. Zentmayer's "Centennial" model has 
 a peculiarly swinging mirror and sub-stage. The mirror- 
 bar is pivoted in the plane of the object on the stage, so 
 that illuminating appliances in the sub-stage may be 
 effected at every angle of inclination, and may even be 
 brought above the stage as a condenser for opaque objects. 
 Mr. Bullock, of Chicago, has also adopted a similar plan 
 in his first-class instruments, and the Bausch & Lomb 
 Optical Company, of Rochester, New York, place a swing- 
 ing-bar below the glass stage of their "Professional" 
 stand, which instrument has many excellent qualities, 
 although it does not reach the idea proposed by Zent- 
 mayer. 
 
 The latter optician has also adopted this mechanism in 
 a cheaper form for students in his "Histological Micro- 
 scope." The "Physician's Microscopes," of the Bausch 
 & Lomb Company, are also models of cheapness and ex- 
 cellence. Beck's "National" microscopes are among the 
 best educational stands. 
 
346 THE MICROSCOPIST. 
 
 IMPROVEMENTS IN OBJECTIVES. 
 
 A laudable desire to place really good objectives in the 
 hands of students at a reasonable price has led to great 
 emulation among opticians. Spencer, Tolles, Wales. Gund- 
 lach, and the Bausch & Lomb Company, in addition to 
 their most perfect objectives, both dry and immersion, 
 which must necessarily demand a high price, have pre- 
 pared others at less cost for professional and students' 
 use, which are worthy of all praise. Some of them fall 
 but little below the performance of the very best glasses. 
 
 Test-objects, such as those referred to at page 56, and 
 which formerly required objectives of best workmanship 
 and highest power, are now resolved by a large number 
 of objectives. The J-inch of Spencer or Tolles, the ith of 
 Gundlach, and even a T 4 D th of Bausch & Lomb, with proper 
 eye-pieces and illumination, will exhibit nearly all which 
 can be desired, yet powers of from Jth to j'gth are still 
 better. For refined histological work ^gth or -^th, or 
 even ^ g th inch (Tolles), will be found most useful. 
 
 The desire to obtain the largest angle of aperture possi- 
 ble has, however, led to a reduction of the working dis- 
 tance, or the distance between the object and front of the 
 objective, so that only the thinnest covers can be used. 
 
 For immersion objectives, also, a variety of fluid media 
 have been proposed, as glycerin, castor oil, oil of cedar, 
 and kerosene. 
 
 IMPROVEMENTS IN EYE-PIECES AND AMPLIFIERS. 
 
 Periscopic eye-pieces, consisting of a piano or double 
 convex field lens and an achromatic meniscus, have been 
 brought to great perfection by E. Gundlach and the Bausch 
 & Lomb Company. Solid eye-pieces by Tolles have also 
 found favor. I have made some improvement in field of 
 view and definition by substituting a meniscus for the 
 
APPENDIX. 347 
 
 field-glass of the periscopic eye-piece. The amplifier re- 
 ferred to at page 26, or an achromatic concave meniscus, 
 is added to this form of eye-piece about three inches from 
 the field-glass. I find this to give better definition than 
 the amplifiers of Zentmayer and Tolles, which are placed 
 at the end of the draw-tube. 
 
 IMPROVEMENTS IN ILLUMINATORS. 
 
 Most of the improvements suggested in illuminators 
 have been connected with oblique light. In Amici's prism, 
 Xachet's prism, Reade's condenser, etc., the purpose is to 
 utilize oblique light and exclude central. In the illumi- 
 nator proposed at page 35 I have combined a condenser 
 with an illuminating prism. Mr. Edmunds (after Mr. 
 "\Venham) has contrived a paraboloid lens with the front 
 cut off flat and polished. This is in fluid contact with 
 the under side of the slide. Mr. Wenbam's reflex con- 
 denser, although difficult to use, is capable of excellent 
 effects. A small lens (plano-convex) placed in immersion 
 contact with the under side of the slide is also used. Dr. 
 Woodward's prism, however, for effectiveness and cheap- 
 ness, bids fair to surpass them all. This is a small right- 
 angled prism, with its base in immersion contact with the 
 slide, receiving the light from the mirror or condenser at 
 right angles to the facet. 
 
 The hemispherical condenser and oblique illuminator of 
 Mr. Gundlach, attached to the "Professional' 7 microscope 
 of the Bausch & Lomb Company, are also well adapted 
 for the purpose. 
 
 DOUBLE-STAINED PREPARATIONS. 
 
 Sections of vegetable tissues present a beautiful appear- 
 ance under the microscope when doubly stained. They 
 should first be soaked in alcohol, if green, to deprive them 
 of chlorophyll, then subjected to a solution of chloride of 
 
348 THE MICROSCOPIST. 
 
 lime ( J- ounce to 1 pint of water) until thoroughly bleached. 
 Soak then in a solution of hyposulphite of soda (1 drachm 
 to 4 ounces water) for an hour, and after thoroughly wash- 
 ing in several changes of water transfer them to alcohol. 
 Prepare some red staining fluid by dissolving J a grain of 
 magenta crystals in 1 ounce of alcohol. Soak the speci- 
 men in this for thirty minutes, then rapidly rinse it in 
 alcohol and place in a blue fluid made by dissolving J 
 grain of anilin blue in 1 drachm of distilled water, adding 
 10 minims of dilute nitric acid and alcohol enough to 
 make 2 ounces. Let the specimen remain only two or 
 three minutes in this, rapidly rinse in alcohol, put in oil 
 of cajeput, thence into turpentine, and mount in balsam. 
 The principle of double staining depends on the affinity 
 which certain dyes have for certain cells. Thus, if sec- 
 tions stained in red or green anilin be soaked in alcohol, 
 and those stained by logw r ood in alum-water, the color 
 will leave the loose parenchyma and be retained by the 
 denser cells, while specimens stained in blue anilin if left 
 in alcohol, and those stained in carmine if left in water, 
 lose color more slowly in the parenchyma than in other 
 parts. 
 
 Eosin-staining . Dilute solutions of eosin, an anilin 
 preparation, 1 part to 1000 of water, has been proposed 
 for animal tissues, since the different parts are differenti- 
 ated by different tints. Sections are stained in a minute 
 to a minute and a half, then washed in water acidulated 
 slightly with acetic acid, and examined in glycerin; or 
 they can be mounted in balsam after the water is removed 
 (see page 80). 
 
 CLASSIFICATION OF CBYPTOGAMIA. 
 
 In addition to the classification given in previous chap- 
 ters, the following, chiefly compiled from the Micrographic 
 Dictionary, may be useful: 
 
APPENDIX. 349 
 
 FERNS. 
 
 Order 1. POLYPODIACEJE. Sporangea on lower sur- 
 face in groups, but never blended. Annulus present, but 
 variable. 
 
 Family I. POLYPODIODIDE.E. Numerous sporanges in 
 sessile sori, divided equally by a vertical annulus. 
 A. No indusium. 
 
 Tribe 1. Polypodies. Sori at apices of veins. 
 
 * Veins pinnate. 
 
 f Margins of fertile fronds not re volute. 
 
 Gen. 1. Pdypodium. Sori globose on apex or back of 
 veins or venules. 
 
 Gen. 2. Marginaria. Sori globose immersed deeply in 
 backs of veins or venules. 
 
 Gen. 3. Pleopeltis. Sori globose on backs of veins or 
 venules, with peltate paraphyses concealing the sporanges. 
 
 f f Margin of fertile fronds revolute. 
 
 Gen. 4. Struthiopteris. Sori globose on backs of veins 
 or venules. 
 
 * * Veins anastomosing. ~No free veins in the areolse. 
 Gen. 5. Dictyopteris. Sori globose on anastomosing 
 
 venules. Venules anastomosing in irregular hexagonal 
 spots. 
 
 * * Veins anastomosing. Free veins in areolae. 
 Gen. 6. Niphobdus. Sori globose on apex of venules. 
 Venules branched, forming transverse rhomboid spots. 
 
 Tribe 2. Acrostichece. Sporangia scattered over the 
 whole surface. 
 
 Gen. 1. Acrostichum. Sori on all the veins and paren- 
 chyma. Veins branched and anastomosing. 
 
 Gen. 2. Campium. Veins branched, with free venules. 
 
350 THE MICROSCOPIST. 
 
 Gen. 3. Polybotrya. Veins pinnate, scarcely anastomos- 
 
 Tribe 3. Tcenitidece. Sori linear, extending to the areolse 
 of the leaves. 
 
 Gen. 1. Pleurogramma. Sori contiguous on each side of 
 the rib, parallel, linear, and continuous. Veins simple. 
 
 Gen. 2. Tcenitis. Sori submarginal in middle of disk 
 of leaf, linear, elongated, and continuous. Veins anasto- 
 mosing into meshes. 
 
 Gen. 3. Notholcena. Sori marginal, linear, continuous. 
 Veins pinnate. 
 
 Tribe 4. Grammitidece. Sori linear, confined to the veins 
 or veinlets. 
 
 Gen. 1. Grammitis. Sori linear or roundish, seated on 
 certain arms of the veins. Veins simple or forked, scarcely 
 anastomosing. 
 
 Gen. 2. Sellignaza. Sori linear or roundish, on certain 
 arms of veins. Veins much branched and anastomosing 
 without free veins. 
 
 Gen. 3. Synamnia. Sori oblong, on back of lowest 
 venule. Veins branched, anastomosing, with free venules. 
 
 Gen. 4. Menisdum. Sori reniform, on back of trans- 
 verse venules. Veins pinnate, anastomosing. 
 
 Gen. 5. Antrophyum. Sori imbedded on the back of 
 all the veins and venules. Veins branched, anastomos- 
 ing. 
 
 Gen. 6. Hemionitis. Sori on back of veins. Veins 
 branched, anastomosing in regular meshes. 
 
 Gen. 7. Gymnogramma. Sori on back of veins. Veins 
 pinnate or forked, scarcely anastomosing. 
 
 Tribe 5. Vittariece. Sori in the grooved margin, which 
 simulates an indusium. 
 
APPENDIX. 351 
 
 Gen. 1. Vittaria. Sori solitary. Fronds ribbonlike or 
 grassy. 
 
 B. With an indusiura. 
 
 Tribe 6. Adiantece. Sori linear, marginal, at apices of 
 veins. Indusium spurious, formed by revolute margin. 
 
 * Sori on the notches of the fronds. 
 
 Gen. 1. Lonchitis. Veins anastomosing. Sori linear, 
 semilunate. Indusium marginal, semilunar. 
 
 Gen. 2. Hypokpis. Veins primate. Sori sub-globose, 
 on inferior border of teeth of frond. Indusium margi- 
 nal, semilunar. 
 
 * * Sori on margin of the frond. 
 
 Gen. 3. Lomaria. Veins primate, forked ; fertile fronds 
 narrower. Sorus linear, continuous. 
 
 Gen. 4. Pte.ris. Veins primate. Sorus continuous. 
 
 Gen. 5. Amphiblestra. Primary veins strong. Venules 
 anastomosing in hexagonal spots. Sorus linear. 
 
 Gen. 6. Litobrochia. Veins anastomosing hexagonally. 
 Sorus linear. 
 
 Gen. 7. Allosorus. Veins primate. Sori at first roundish, 
 then confluent and linear, covered by the reflected margin. 
 
 Gen. 8. Cassebeera. Veins primate. Sori two under 
 each notched tooth of the leaf. 
 
 Gen. 9. Adiantum. Veins fan-primate. Sori linear or 
 semilunar, free within. 
 
 Gen. 10. Hewardia. Veins reticulated. Sori linear. 
 Indusium linear or semilunar. 
 
 Gen. 11. Cheilanthes. Veins primate. Sori sub-globose, 
 minute, covered by reflexed apex of tooth and the indu- 
 sium. 
 
 Tribe 7. Dicksoniece. Sori globose, apical. Indusium 
 lateral, two-valved. 
 
 Gen. 1. Dicksonia. Valves of indusium unequal. 
 Gen. 2. Cibotium. Valves nearly equal. 
 
352 THE MICROSCOPIST. 
 
 Gen. 3. Cystodium. True indusium plane, false one 
 hoodlike. 
 
 Gen. 4. Thrysopteris. Sori semiglobose. Indusium cup- 
 like. Sori on a thryse (leaf without parenchyma). 
 
 Gen. 5. Deparia. Sori as in 4. Parenchyma of leaf 
 developed. 
 
 Tribe 8. Davalliece. Sori apical, inframargiual. Indu- 
 sium one-valved. 
 
 Gen. 1. Davallia. Sori globose. Indusium cup-shaped, 
 the mouth truncated. Veins primate. 
 
 Gen. 2. Lindscea. Sorus linear, continuous. Indusium 
 parallel with leaf margin, free outside. Veins dichoto- 
 mous. 
 
 Gen. 3. Dictyoxyphium. Sorus and indusium as in 2. 
 Veins anastomosing with free venules. 
 
 Gen. 4. Schizoloma. Sorus and indusium as in 2. Veins 
 anastomosing in hexagonoid meshes. 
 
 Tribe 9. Aspleniece. Sori on veins. Indusium persist- 
 ent, lateral, the margin free. 
 
 Gen. 1. Scolopendrium. Veins primate. Sori linear, in 
 pairs on adjacent sides of two parallel veinlets. 
 
 Gen. 2. Antigramma. Veins primate, veinlets anasto- 
 mosing. Sori linear, in pairs facing together. 
 
 Gen. 3. Campto&orKS. Veins as 2. Sori elongated, di- 
 verging. 
 
 Gen. 4. Diplazium. Veins primate, veinlets free. Sori 
 linear, in pairs back to back. 
 
 Gen. 5. Oxygonium. Veins primate, veinlets anasto- 
 mosing at the ends. Sori as 4. 
 
 Gen. 6. Asplenium. Veinlets free. Sori linear, single 
 on back of vein or veinlet. 
 
 Gen. 7. Ceterach. Indusium replaced by scales. Sori 
 linear on back of veins. 
 
 Gen. 8. Neottopteris. Veinlets anastomosing at ends. 
 Sori linear, single. 
 
APPENDIX. 353 
 
 Gen. S.Athyrium. Veins primate. Sori straight, curved, 
 or reniform, but attached by a linear edge. 
 
 Gen. 10. Blechuum. Sori marginal, somewhat conflu- 
 ent. Indusium opening inwards. 
 
 Gen. 11. Doodia. Veins parallel, anastomosing slightly. 
 Sori lunate or linear, in one or two rows parallel with 
 midrib. Indusium flat. 
 
 Gen. 12. \Yoodwardia. Veinlets form hexagonal meshes. 
 
 O 
 
 Sori lunate or linear, parallel with midrib in one row. 
 Indusium convex, immersed. 
 
 Gen. 13. Cystopteus. Indusium suborbicular, fixed by 
 a lateral inferior point. 
 
 Gen. 14. Onoclea. Fertile pinnae contracted into glob- 
 ules. Indusium lunate, attached on a short horizontal 
 veinlet. 
 
 Tribe 10. Aspidiece. Sori subglobose. Indusium with 
 central or eccentric point of attachment, free all round. 
 
 Gen. 1. Lastrcea. Indusium reniform. Veinlets free 
 at ends. 
 
 Gen. 2. Nephrolepis. Indusium reniform. Sori on tips 
 of upper veinlets. Petioles articulated with the rachis. 
 
 Gen. 3. Nephr odium. Indusium reniform, veinlets in- 
 osculating. 
 
 Gen. 4. Aspidium. Indusium orbicular, peltate. Veins 
 branched, anastomosing hexagonally, with free veinlets. 
 
 Gen. 5. Polystichum. Indusium orbicular, peltate. Sori 
 on middle of veins below the bifurcations. 
 
 Gen. 6. Sagenia. Indusium orbicular, peltate. Vein- 
 lets anastomosing hexagonally without free ringlets. 
 
 Gen. 7. Fadyenia. Indusium cordate. Sori apical, bi- 
 seriate. Vein4ets reticulate. 
 
 Gen. 8. Didymochlcena. Indusium oblong-elliptic, fixed 
 in the middle by a longitudinal crest. 
 
 Gen. 9. Matonia Indusium orbiculate, peltate, umbo- 
 nate, the margins deflexed, covering about six sporanges. 
 
 23 
 
354 THE MICROSCOPIST. 
 
 Tribe 11. Peranemece. Indusium inferior, ultimately 
 lobed or ciliated. 
 
 Gen. 1. Peranema. Sori pedunculate. Indusium cup- 
 shaped, splitting into 2-4 lobes. Sporanges on punctiform 
 receptacle. Veins pinnate. 
 
 Gen. 2. Diacalpe. Sori regular. Indusium sessile, 
 spherical, at first closed. Sori on a punctiform receptacle, 
 then bursting irregularty at the summit. 
 
 Gen. 3. Woodsia. Sporanges pedicellate, inserted at 
 bottom of indusium which is cup-shaped and hairy at 
 margin. Veins pinnate. 
 
 Gen. 4. Hypoderris. Sporanges on almost obsolete axis- 
 Indusium cup-shaped, fringed at margin. Veins anasto- 
 mosing. 
 
 Family II. CYATH^EEJS. Numerous sporanges, united 
 in sori on a salient axis, with a somewhat oblique annulus. 
 
 A. Sori without indusia. 
 
 Gen. 1. Alsophila. Sori globose, regularly arranged. 
 Sporanges on globose axis and imbricated. 
 
 Gen. "2. Tricfiopteris. Sori globose, regularly arranged, 
 laterally confluent. Sporanges on globose axis, areolate 
 and crinite with long hairs. 
 
 Gen. 3. Metaxya. Sori globose, each fertile vein bear- 
 ing several, irregularly scattered. Sporangia on globose 
 axis, beset with long articulated hairs. 
 
 B. Sori indusiate. 
 
 Gen. 4. Hemitelia. Sori globose, each solitary on a 
 pinnule. Indusium an ovate, concave, torn scale, at lower 
 side of the base. 
 
 Gen. 5. Cnemidaria. Sori globose, regularly arranged. 
 Indusium forming an involucre, at length irregularly torn 
 or partite. 
 
 Gen. 6. Cyathea. Sori hemispherical, regular. Indu- 
 sium first closed, then bursting and cup-shaped. 
 
APPENDIX. 355 
 
 Gen. 7. Schizoccena. Sori regular. Indusium of six 
 lobes surrounding the globose receptacle. 
 
 Family III. GLEICHEXIE^I. Sporanges united in fours 
 into sori, and surrounded by an oblique annulus, like a 
 turban. 
 
 Gen. 1. Gleichemia. Sporangia in roundish sori. Indu- 
 sium absent. Leaves forking. 
 
 Gen. 2. Platyzoma. Sporanges in pointlike sori. In- 
 dusium spurious, formed by re volute margin of leaf, 
 leaves undivided. 
 
 Family IV. PARKERiE^:.--Sporanges ununited into sori, 
 and divided equally by a vertical annulus. 
 
 Gen. 1. Ceratopteris. Sporanges surrounded by a broad, 
 complete, articulated annulus, placed on longitudinal 
 veins. Spores globose, trifariously streaked. 
 
 Gen. 2. Parkeria. Sporanges with almost obsolete 
 basilar annulus, or longitudinal veins. Spores three-sided, 
 concentrically streaked. 
 
 Family V. OSMUNDE^I. Sporanges united in sori, and 
 covered on the back by a broad and imperfect annulus. 
 
 Gen. 1. Osmunda. Sporangia on metamorphosed pin- 
 nules. 
 
 Gen. 2. Todea. Sporangia on unchanged pinnules. 
 
 Family VI. SCHIZ.EEJE. Sporanges united in sori, and 
 annulus like a skull-cap with radiating streaks. 
 
 Gen. 1. Aneimia. Sporangia twin, sessile in two rows, 
 on lateral lobes of leaf, contracted into a panniculate irn- 
 marginate rachis, naked, splitting longitudinally outside. 
 Xo indusium. 
 
 Gen. 2. Schizcea. Sporanges sessile in two or four rows 
 in linear membranous-margined lobes, pectinately oppo- 
 
356 THE MICROSCOPIST. 
 
 site or digitate at apex of leaf, set among hairs, splitting 
 longitudinally on the outside. No indusium. 
 
 Gen. 3. Lygodium. Sporangia sessile, alternately bi- 
 seriate on marginal lobes of leaf, splitting longitudinally, 
 each veiled by a scalelike, hood-shaped indusium adhering 
 transversely to the nerves. 
 
 Gen. 4. Mohria. Sporangia sessile in one row, close to 
 margin of leaf, splitting longitudinally on the outside. A 
 spurious indusium formed by revolute margin of leaf. 
 
 Order 2. MARATTIACE^E. Sporanges on lower sur- 
 face, usually blended together, or very closely approxi- 
 mated. No annulus. 
 
 Gen. 1. Angiopetris. Sporangia in two rows near apex 
 of transverse veins, distinct, forming linear sori, opening 
 by a slit on outer side. No indusium. , 
 
 Gen. 2. Kaulfiissia. Sporangia on anastompses of 
 veins, radiately connate, forming roundish sori, opening 
 by a slit at apex. 
 
 Gen. 3. Marattia. Sporangia in two rows near apex of 
 transverse veins, connate, forming oblong sori, gaping 
 transversely by a vertical slit. Indusia connate with 
 sori. 
 
 Gen. 4. Eupvtium. Sporangia as 3, but pedicellate. 
 
 Gen. 5. Dancea. Sporangia in two rows, near trans- 
 verse veins, connate into linear sori, opening by a pore. 
 Indusia superficial, encircling the sori. 
 
 Order 3. OPHIOGLOSSE^E. Sporanges on lower sur- 
 face of leaf (reduced to mere ribs), never blended. No 
 annulus. 
 
 Gen. 1. Ophioglossum. Sporanges dehiscing transversely, 
 connate on an undivided distichous spike. 
 
 Gen. 2. Botrychium. Sporanges as last, on a distichous, 
 secund, bi-tri-pinnate spike. 
 
 Gen. 3. Helminthostachys. Sporanges dehiscing exter- 
 
APPENDIX. 357 
 
 nally, vertically, from base to middle, collected in whorls, 
 with crestlike appendages, and stalked, arranged distich- 
 ously on an elongated spike. 
 
 Order 4. HYMEXOPHYLLE^E. Sporanges attached 
 to a common stalk, prolonged from end of vein of leaf, 
 and contained in a kind of cup formed by a lobe of leaf 
 above and indusial lobe from lower surface of leaf. 
 Obliquely transverse annulus. 
 
 Gen. 1. Trichomanes. Sporanges sessile around base of 
 an exserted filiform column projecting from margin of 
 leaf, surrounded by a cup shaped indusium continuous 
 with leaf. 
 
 Gen. 2. Hymen&phyUum. Sporanges sessile up to sum- 
 mit of a column projecting from the margin of the leaf, 
 sub-elevated, but not exserted beyond the iudusium, which 
 is two-valved. 
 
 Gen. 3. Loxsoma. Sporanges stalked, inserted up to 
 summit of a sub-elevated exserted column in margin of 
 leaf, surrounded by an indusium, with truncated mouth, 
 entire. 
 
 MICROSCOPIC FUNGI. 
 
 Order COXIOMYCETES. The mycelium may be short 
 filaments converted into spores, or a flocculeut patch in 
 decaying matter or under the epiderm of plants, or more 
 completely organized into hollow conceptacles containing 
 spore-bearing filaments. 
 
 Family I. SPH^EROXEMEI. Couceptacles rising from mi- 
 croscopic mycelia growing beneath the epidermis of leaves, 
 stems, etc., containing a chamber lined by a perithecium 
 bearing single, often septate spores, and bursting by a pore 
 at the summit. 
 
 Gen. 1. Coniothyrium. Conceptacle free, membranous, 
 opening by an irregular pore at the summit. Spores 
 globular. 
 
358 THE MICROSCOPIST. 
 
 2. Leptostroma. Conceptacle innate, subumbonate in 
 tbe centre, dimidiate, at length falling off, leaving a thin 
 disk. 
 
 3. Phoma. Conceptacle ostiolate, very thin, innate, 
 immersed, rounded, with a simple pore. Spores oblong, 
 simple. 
 
 4. Leptothyrium. Conceptacle operculate, innate, shield- 
 shaped, not radiate-fibrous. Spores spindle-shaped, simple. 
 
 5. Actinothyrium. Conceptacle operculate, innate, etc., 
 as 4. 
 
 6. Microthedum. Conceptacle indehiscent, membranous, 
 immersed, endophytic. Spores simple. 
 
 7. Cryptosporium. Conceptacle membranous, opening 
 irregularly at summit. Spores spindle-shaped, simple. 
 
 8. Sphceronema. Conceptacle horny, innate-superficial, 
 produced into a neck, ostiole simple. Spores oblong, 
 simple. 
 
 9. Acrospermum. Conceptacle leathery externally, 
 fleshy within, elongate-clavate, ostiole simple. Spores 
 stick-shaped, simple. 
 
 10. Diplodia. Conceptacle horny, innate-superficial or 
 immersed, perforated by a pore or irregularly opened or 
 ostiolate, ostiole more or less produced. Spores ovoid or. 
 ellipsoid, double, then halved into compressed-ternate 
 semi-ellipsoid sporules. 
 
 11. Hendersonia. Conceptacle fleshy, innate superfi- 
 cially or immersed, perforated by a pore, opening irregu- 
 larly or ostiolate, ostiole produced. Spores globose, cylin- 
 drical or discoid. 
 
 12. Septoria. Conceptacle horny, innate-immersed, 
 rounded, ostiole simple. Spores cylindrical, septate. 
 
 13. Vermicularia. Conceptacle bristly, depressed, 
 bursting irregularly. Spores minute, linear. 
 
 14. Neottiospora. Conceptacle immersed. Spores ap- 
 pendaged at one end with sbort hyaline threads. 
 
 15. Asteroma. Conceptacle very small, slightly promi- 
 
APPENDIX. 359 
 
 neut, close, subconfluent, seated on more or less radiating 
 fibrils. 
 
 16. Discosia. Conceptacles innate, somewhat carbona- 
 ceous, at length collapsed and plicate, ostiole perforated. 
 Spores fusiform, produced at both ends into a threadlike 
 point. 
 
 17. Prosthemium. Conceptacles horny, immersed, os- 
 tiole simple. Spores transversely septate, verticulate at 
 the apex of thin filaments. 
 
 18. Angiopoma. Conceptacles free, membranous, some- 
 what horny, cup-shaped, dehiscing by a circular mouth, 
 provided with a fugarious epiphragtn. Spores affixed at 
 base, stalked, septate. 
 
 19. Piggotia. Conceptacles irregular, thin, obsolete be- 
 neath, confluent, bursting by irregular crack; spores on 
 short stalks, largish, obovate, somewhat constricted at 
 base. 
 
 20. Phlyctcena. Conceptacle spurious, formed by the 
 blackened epidermis ; spores fusiform, cuspidate, septate, 
 accompanied by a gelatinous mass. 
 
 21. Glceosporium. Conceptacle absent ; spores covered 
 by cuticle which separates ; spores stalked, elliptical, sim- 
 ple, exuding a gelatinous tendril. 
 
 22. Dilophosphora. Conceptacle immersed in a spurious 
 stroma, covered, perforated by a pore ; spores cylindrical, 
 continuous, crowned at both ends with radiating filiform 
 appendages. 
 
 23. Sphceropsis. Conceptacle spherical, immersed, sub- 
 innate, astomous, bursting by separation of epidermis or 
 irregularly. Spores simple. 
 
 Family II. MELANCONIEI. Conceptacles as in the pre- 
 ceding, but without a proper perithecium ; spores elon- 
 gated. 
 
 Gen. 1. Sporidia globose, simple, adhering to form a 
 nucleus, at length breaking out free. Color black. 
 
360 THE MICROSCOPIST. 
 
 2. Papularia. Sporidia quite simple, collected in groups 
 under epiderm of dead plants, set free in a pulverulent 
 patch by the decay of the epidermis. 
 
 3. Stilbospora. Sporidia septate (septa evanescent), full 
 of sporidiola, adhering in a 'nucleus, at length breaking 
 out. 
 
 4. Didymosporium.-^-As the last, but the sporidia didy- 
 rnous (septate in middle). Color black or fuscous. 
 
 5. Cytispora. Sporidia simple, stick-shaped, minute, in 
 a multilocular nucleus, at length opening by a common 
 apical pore and emerging as a gelatinous tendril. 
 
 6. Mdasmia. Sporidia minute, stick-shaped, in a flat, 
 thin nucleus, which bursts at apex and extrudes the spores 
 in a gelatinous globule. 
 
 7. Micropera. Sporidia linear, curved, formed in nu- 
 clei, bursting by distinct pores, and discharged mixed with 
 jelly. 
 
 8. Ceuthospora. Sporidia simple, ovate, contained in 
 several globose nuclei in a common stroma, escaping by a 
 simple lancinate pore. 
 
 9. Nemaspora. Sporidia simple, spindle-shaped, in nu- 
 clei in a common grumous stroma and opening by a com- 
 mon pore. 
 
 10. Discella. Sporidia elongated, simple or uniseptate, 
 stalked, in a nucleus with perithecium. 
 
 11. Cylindrosporium (Glceosporium). Sporidia simple, 
 elliptical, stalked, in nucleus covered only by cuticle of 
 leaf, finally extruded in a gelatinous tendril. 
 
 12. Coryneum. Sporidia spindle-shaped, multiseptate, 
 stalked, crowded, breaking out on surface as a pulvinate 
 disk. 
 
 13. JBactridium. Sporidia spindle-shaped, multiseptate, 
 transparent at ends, tufted on a superficial creeping my- 
 celium. 
 
 14. Eriospora. Sporidia filiform, originally attached in 
 
APPENDIX. 361 
 
 fours upon sporophores, in groups of globose nuclei open- 
 ing by a common pore. 
 
 15. Ckeirospora. Sporidia simple, crowded in tufts at 
 apex of a filiform sporophore, in moniliform rows. 
 
 Family III. PHRAGMOTRICHACE^;. Conceptacles horny, 
 breaking through epidermis of leaves, etc., at first closed, 
 then bursting longitudinally ; spores septate, and in chain- 
 like series, with paraphyses on internal walls of concep- 
 tacles. 
 
 Gen. 1. Endotrichinn. Conceptacle innate or immersed, 
 bursting by a longitudinal slit ; spores globular, simple. 
 
 2. Schizothccium. Conceptacle superficial, bursting 
 laterally ; spores globular, simple. 
 
 3. Pilidium. Conceptacles simple, sessile, rounded, 
 bursting by stellate fission ; spores spindle-shaped, simple. 
 
 4. Exdpula. Conceptacle cup-shaped, membranous, 
 sessile, naked ; spores spindle-shaped. 
 
 5. Dinemasporium, Conceptacle cup-shaped, membra- 
 nous, sessile, closed by villi, and at length open ; sporige- 
 nous layer discoid, dissolving, with cylindric, elongate, 
 filiform spores. 
 
 6. Myxormia. Conceptacle thin, cup-shaped, open, 
 formed of elongated cells. Pedicels of spores delicate. 
 Spores oblong, chained together, at length free, involved 
 in mucus. 
 
 7. Cystatricha. Conceptacle bursting by a longitudinal 
 slit ; pedicels of spores branched, articulate, somewhat 
 beaded. 
 
 8. Bloxamia. Conceptacle delicate, hyaline, upper part 
 evanescent and forming a rim. Spores quadrate in crowded 
 tubules. 
 
 9. Phragmotrichum. Conceptacle horny, carbonaceous, 
 at first closed, then splitting by longitudinal fissure ; 
 fertile filaments mixed with inarticulate paraphyses; 
 spores compound and chained in series. 
 
362 THE MICROSCOPIST. 
 
 Family IV. TORULACEI. Mycelium filamentous, grow- 
 ing on the surface of decayed vegetables, bearing erect 
 filaments, terminating in rows of simple or compound 
 spores. 
 
 Gen. 1. Torula. Spores in beaded chains, simple, readily 
 separating, placed on short continuous or septate pedicel. 
 
 2. Bispora. Spores uniseptate. 
 
 3. Septonema. Several transverse septa in the spores. 
 
 4. Alternaria. Cellular spores connected by filiform 
 isthmus. 
 
 5. Sporidesmium. Spores in tufts, straight, subclavate 
 or fusiform, shortly stalked or sessile, transversely sep- 
 tate or cellular. 
 
 6. Sporochisma. Filaments erect, simple, external mem- 
 brane inarticulate. Spores articulate in fours. 
 
 7. Tetraploa. Spores sessile, quadriseptate, in bundles 
 of four, each crowned with a bristle. 
 
 8. Coniothedum. Spores without septa, in heaps, finally 
 separating into a powder. 
 
 9. Echinobotryum. Spores rounded apiculate, in fasci- 
 cles, or erect annulated filaments. 
 
 10. Sporendonema. Erect filaments with single rows 
 of spores in the interior. 
 
 11. Spiloccea. Spores globose, adhering together and to 
 the matrix, forming spots laid bare by separation of epi- 
 dermis. 
 
 12. Achorion. Mycelium ramose, articulated, joints 
 terminating in round, oval, or irregular spores (conidia?). 
 
 13. Speira. Spores connate in concentric filaments, 
 forming horseshoe-like lamina, finally separating. 
 
 14. Trimmatostroma. Spores curved, multiseptate, in 
 beaded rows, separating. 
 
 15. Gyrocerus. Spores connate in spirally coiled fila- 
 ments, separating. 
 
 16. Dictyosporium. Spores tongue-shaped, reticularly 
 cellular. 
 
APPENDIX. 363 
 
 Family V. UREDINEI. Mycelium a filamentous mass 
 growing in the interior of living vegetable structures, 
 finally breaking out on the surface in patches, margined or 
 naked, and bearing simple or compound spores, single or in 
 beaded series. 
 
 The following is Tulasne's synopsis of the family : 
 
 I. Albuginei (white or pale-yellow, heterosporous). 
 
 Gen. I. Cystopus. 
 
 II. JEcidinei (with a peridium, homcesporous). 
 
 2. Cseoma. 
 
 3. ^Ecidium. 
 
 4. Raestelia. 
 
 5. Peridermium. 
 
 III. Melampsorei (solid, pulvinate, biform). 
 
 6. Melampsora. 
 
 7. Coleosporium. 
 
 IY. Phragmidiacei (pulverulent, biform, infuscate). 
 
 8. Phragmidium. 
 
 9. Triphragmidium. 
 
 10. Pucciuia. 
 
 11. Uromyces. 
 
 12. Pileolaria. 
 
 V. Pucdniei (fleshy, ligulate or tremelliform, naked, 
 and uniform in the fruits). 
 
 13. Podisoma. 
 
 14. Gymnosporangium. 
 
 VI. Cronartiei (peridiate, biform, ligulate). 
 
 15. Cronartium. 
 
 Family VI. USTILAGINEI. Similar to the last, but grow 
 in the interior of organs, especially ovaries and anthers, 
 of plants. Spores break up without bursting through to 
 surface, so as to leave a cavity full of dust-like spores. 
 
 I. Ustilaginei Veri. Stroma at first mucilaginous, en- 
 tire, or soon broken up into variously conglomerated 
 
364 THE MICROSCOPIST. 
 
 masses, then into unappendaged spores ; few or no fila- 
 ments persistent. 
 
 1. Ustilago. Spores simple. 
 
 2. Thecaphora. Spores compound. 
 
 II. Tilletiei. Stroma of interwoven fragile filaments ; 
 spores acrogenous on their ramules, often appendaged 
 when free. 
 
 3. Tilletia. 
 
 Order HYPHOMYCETES. Mycelium filamentous, 
 growing as moulds over dead or living organic substances. 
 The erect filaments bear terminal, free, single, simple, or 
 septate spores. 
 
 Family I. ISARIACEI. Receptacle clavately branched, 
 of filaments attached in their whole length. Spores sim- 
 ple, attached to simple pedicels. 
 
 Gen. 1. Isaria. Receptacle of interwoven filaments, 
 or cellularly fleshy. Spores on simple sporophores arising 
 on all sides. 
 
 2. Anthina. Receptacle of parallel filaments, feathery 
 or villous at the summit where they form the sporo- 
 phores. 
 
 8. Ceratium. Receptacle horn-shaped, mucilaginous, 
 with filaments which collapse into granules (conidia), and 
 free sporidia. 
 
 Family II. STILBACEI. Receptacle wartlike or clavate 
 above, stalked below, of filaments packed, coherent, ter- 
 minating singly in free spores. 
 
 Gen. 1. Stilbum. Receptacle clavate or capitate at sum- 
 mit. Spores simple. 
 
 2. Pachnocybe. Receptacle stipitate, clavate, floccose, 
 filaments twisted, head finally pruinose, with simple 
 spores. 
 
 3. Periconia. Receptacle of coalescent crowded, paral- 
 
APPENDIX. 365 
 
 lei filaments, or cell ularly fleshy ; spores simple, crowded, 
 on simple sporophores arising at summit and on the 
 stalk. 
 
 4. Tuhercularia. Receptacle fleshy, of continuous sterile 
 and threadlike beaded fertile filaments. Finally indurated, 
 floccose, with spores scattered over it, or falling into 
 powder. 
 
 5. Periola. Receptacle cellular, sessile, fertile filaments 
 abbreviated, torulose, mixed with septate lax sterile fila- 
 ments. 
 
 6. Volutella. Receptacle cellular, compact, with long 
 rigid bristles ; spores spindle-shaped, septate, on continu- 
 ous short filaments, all over the receptacle. 
 
 7. Fusarium. Receptacle cellular, gelatinous ; spores 
 spindle-shaped, simple, somewhat curved, on simple fila- 
 ments forming a discoid stratum. 
 
 8. Illosporium. Receptacle sub-gelatinous, diffluent ; 
 spores simple, pellucid, generally with hyaline envelope 
 on short filaments. 
 
 9. Epicoccum. Receptacle cellular, on effused patch ; 
 spores four-sided, cellular, singly to short filaments. 
 
 Family III. DEMATIEI. Mycelium filamentous, spores 
 compound or simple, rising from apices of erect, solid, cor- 
 ticate, subopaque filaments, or produced from solution of 
 the plants. 
 
 Gen. 1. Cephalotrichum. Fertile filaments stalklike, 
 erect, septate, terminating in a globose capitule formed 
 by radiating forked or ternate branches bearing globular 
 spores at the tips. 
 
 2. Sporocybe. Filaments fibrous, subulate, capitate, 
 with simple spores conglobated into a terminal head. 
 
 3. (Edemium. Filaments rigid, erect, almost continu- 
 ous, or annulated, bearing at the sides globular masses of 
 spores. 
 
 4. Myxotrichum. Filaments erect, scarcely septate ; 
 
366 THE MICROSCOPIST. 
 
 fertile branches crowned by globules of heterogeneous con- 
 glutinated spores. 
 
 5. Bolacotricha. Filaments simple, uniformly articulate 
 at apex ; spores conglomerate, large, globular, shortly 
 stalked, contents granular. 
 
 6. Hdminthosporium. Filaments erect, simple, septate ; 
 spores transversely septate. 
 
 7. Triposporium. Filaments erect, septate, sterile 
 branches solitary, more or less spreading ; fertile branches 
 shorter, at tips solitary, stellate, shortly stalked spores. 
 
 8. Helicosporium. Filaments subulate, closely septate, 
 diaphanous at summit ; spores threadlike, septate, spirally 
 coiled, then expanding elastically. 
 
 9. Cladotrichum. Filaments septate, branched, branches 
 and branchlets with septate spores at tips. 
 
 10. Dematium. Filaments septate, with verticillate 
 branchlets below, simple and whiplike above ; spores 
 crowded on apices of ramules. 
 
 11. Cladosporium. Filaments septate above, bearing 
 spores in rows forming short moniliform branchlets. 
 
 12. Macrosporium. Filaments suberect, septate, deli- 
 cate, evanescent, with erect stipitate spores, with many 
 transverse and usually some longitudinal septa. 
 
 13. Arthrineum. Filaments tufted, suberect, annulate 
 with opaque septa ; spores fusiform, septate, large. 
 
 14. Camptoum. Filaments as preceding ; spores ovate, 
 curved, small. 
 
 Family IV. MUCIDINES. Mycelium filamentous, spores 
 solitary, or crowded on articulated or branched tubular 
 and pellucid filaments, soon separating and mingling with 
 the mycelium or adherent in chained rows (moulds, mil- 
 dews, etc.). 
 
 A. Fertile filaments (pedicels) simple or branched, ter- 
 minating in single spores, or a short row. 
 
 * Spores simple. 
 
APPENDIX. 367 
 
 1. Botrytis. Pedicels erect, septate, branched ; branches 
 and branchlets septate ; spores solitary, on tips of branch- 
 lets, which are racemose, umbellate, cymose, etc. 
 
 2. Peronosj)ora. Like 1, but pedicels without septa. 
 
 3. Verticillium. Pedicels erect, septate, with whorled 
 branches terminating in a solitary spore or a short row of 
 spores. 
 
 4. Acremomum. Pedicels short, subulate, branches from 
 a horizontal filament, bearing single smooth spores. 
 
 5. Zygodesmus. Like 4, but with echinulate spores. 
 
 6. Oidium. Pedicels simple, short, erect, clavate, sep- 
 tate, with one, sometimes two, oval spores. 
 
 7. Fasidium. Spores elongate, fusiform. 
 
 8. Menispora. Pedicels erect, septate, with fusiform 
 or cylindric spores, at first joined in bundles. 
 
 9. Sceptromyces. Pedicels erect, geniculate, verticil- 
 lately branched ; branches short, racemose ; spores in 
 grapelike bunches. 
 
 * * Spores septate. 
 
 10. Brachydadium. Pedicels branched above, septate, 
 moniliform ; branches and branchlets forming a sporifer- 
 ous capitulum ; spores transversely septate. 
 
 11. Trichothecium. Pedicels in tufts, the central erect, 
 fertile ; spores acrogeuous, didymous, free, commonly 
 loosely heaped. 
 
 12. Cephalothecium. Pedicels simple, continuous, with 
 terminal head of didymous spores. 
 
 B. Erect filaments (pedicels) terminating in strings of 
 spores. 
 
 * Spores simple. 
 
 13. Penicillium. Pedicels erect, septate, penicillately 
 branched above ; branches and branchlets septate ; strings 
 of spores at tips of branches. 
 
 14. Sporotrichum. Pedicels simple or slightly branched, 
 septate and articulate, articulations remote, inflated ; 
 spores simple, usually in heaps among the filaments. 
 
\ 
 368 THE MICROSCOPIST. 
 
 15. Briarea. Pedicels septate, with terminal monili- 
 form chains of spores, crowded into a head, 
 
 16. Gonatorrhodum. Pedicels septate, with chains of 
 spores in a terminal head, and in whorls at the joints. 
 
 * * Spores septate. 
 
 17. Dendryphium. Pedicels septate, nnbranched; 
 strings of spores in a bunch at apex ; spores septate. 
 
 18. Dadylium. Pedicels septate, branched above; 
 strings of septate spores singly or in pairs, at apices of 
 branches. 
 
 C. Fertile filaments (pedicels) inflated at the tips or at 
 various points in their length, with projecting points or 
 warts, on the inflations bearing 
 
 ' O 
 
 * Simple spores. 
 
 19. Aspergillus. Pedicels continuous, erect, simple fila- 
 ments, inflated into a little head at the summit, bearing 
 moniliform chains of spores, crowded into a capitulum. 
 
 20. Rhinotrichum. Pedicels erect, septate, sometimes 
 sparingly branched, the apices clavate, cellular, bearing 
 scattered points supporting simple spores. 
 
 21. Papuloespora. Pedicels short lateral branches from 
 a creeping filament, terminating in cellular heads beset 
 with spores on the areolse. 
 
 22. Rhopalomyces. Pedicels erect, not septate, termi- 
 nating in cellular heads, with simple spores on the areolee. 
 
 23. Stachylidium. Pedicels articulate, whorled-branched 
 above ; branches geniculate and articulate ; spores sub- 
 pedicilate, in little heads inserted at tips of branches. 
 
 24. Gonatobotrys. Pedicels septate, with joints swollen 
 at intervals, the swollen joints bearing globular heaps of 
 spores on short spines spirally arranged. 
 
 25. Acmosporium. Pedicels septate, branched above ; 
 branches and branchlets forming a cyme, thickened at the 
 apex, and furnished with globular capitules covered with 
 points ; spores attached on the points of capitules. 
 
APPENDIX. 369 
 
 26. Haplotrichum. Pedicles septate, terminating in con- 
 tinuous, solitary, sporiferous head. 
 
 27. Actinodadium. Pedicles septate, umbellately 
 branched at summit; spores accumulated at tips of 
 branches. 
 
 28. Botryiosporium. Pedicles septate, with short spine- 
 like branchlets above, spirally arranged, and terminating 
 in four or five short points which support globular heads 
 of spores. 
 
 * * Spores septate. 
 
 29. Arthrobotrys. Pedicles simple, septate, with joints 
 swollen at intervals and clothed with spines bearing didy- 
 mous spores in globular heaps. 
 
 5. Family Sepedoniei. Mycelium filamentous, spores 
 usually heaped together on the mycelium, and apparently 
 springing out of it, without erect pedicles. 
 
 1. Artotrogus. Filaments creeping, persistent; spores 
 from middle of filaments, simple, at length free, spinous. 
 
 2. Sepedonium. Filaments woolly, septate, evanescent; 
 spores globose, connate, scabrous, stipitate, solitary, at 
 length heaped together. 
 
 3. Fussisporium. Spores fusiform or cylindrical, glued 
 in heaps on the gelatinous matrix. 
 
 4. Epochnium,. Spores heaped, oblong, apiculate, sep- 
 tate, adnate to the matrix, interwoven with effused, 
 tangled, slender filaments of mycelium. 
 
 5. Psilonia. Spores simple, pellucid, not glued together, 
 at first covered with conveying filaments of mycelium. 
 
 6. Monotospora Eutophyte. Filaments creeping, evan- 
 escent ; spores globose, solitary, terminal, at length free. 
 
 7. Asterophora. Filaments creeping (over larger fungi) ; 
 spores on short ramules, vesicular, stellate. 
 
 8. Acrospeira. Filaments creeping, ramuli branched, 
 the fertile terminating in a spiral coil of about three 
 joints, one of which swells into a rough-coated spore. 
 
 24 
 
370 THE MICROSCOPIST. 
 
 9. Zygodesmus. Filaments creeping, branched, with 
 short rarnuli bearing echinate spores, the pedicles with a 
 lateral indentation looking like a joint. 
 
 Order PHYSOMYCETES, or Mucoroidece (Moulds). 
 Mycelium (microscopic) filamentous, bearing stalked sacs 
 (peridiola) containing numerous minute sporules. 
 
 family I. ANTENNARIEI (doubtful). Mycelium radiate 
 or erect, bearing sessile globular peridioles, filled with 
 ovate spores, discharged by rupture of sac at apex. Form 
 flocculent or byssoid patches on leaves or bark, and appear 
 to be merely states of other genera. 
 
 Family II. MUCORINI. Mycelium filamentous, vague, 
 giving off erect simple or branched filaments terminating 
 in vesicular cells (peridioles) full of minute spores ; often 
 with central column in the interior. Form flocks and 
 clouds on decaying matters- 
 
 1. Phycomyces. Peridiole pear-shaped, separated from 
 apex of pedicle by an even joint; opening by an umbili- 
 cus. Spores oblong, large. Filaments tubular, continu- 
 ous, shining. 
 
 2. Hydrophora. Peridiole subglobose, membranous, de- 
 hiscent, at first crystalline, aqueous, then turbid, and at 
 length indurated; bolumella absent; spores simple, con- 
 globated. 
 
 3. Mucor. Peridiole subglobose, separating like a cap 
 (an annular fragment attached), from the erect, simple 
 pedicle, or bursting irregularly; columella cylindric or 
 ovate, spores simple. 
 
 4. Acrostalagmus (?). Peridioles globose, with a colu- 
 mella ; at the points of doubly- verticillate branches from 
 an erect pedicle. 
 
 5. JEgerita. Peridiole spherical, very fugacious ; spori- 
 dia scattered like meal over the grumous receptacle. 
 
APPENDIX. 371 
 
 6. Pilobolus. Peridiole globular, separating like a cap 
 from the short stalk of a single cell, attached on a uni- 
 cellular ramified mycelium ; columella conical ; spores 
 numerous, free in the peridiole. 
 
 7. Syzygit.es. Filaments erect, simple, branched above, 
 branches and branchlets di- or tri-chotomous, fertile 
 branches forcipate, bearing pairs of opposite internal cla- 
 vate branches which subsequently coalesce. 
 
 8. Eurotium. Peridiole cellular, membranous, sessile, 
 at length bursting irregularly ; spores produced by a cen- 
 tral cellular nucleus, which breaks up into numerous pa- 
 rent cells (asci), in which four to eight minute spores are 
 formed, and finally set free ; filaments of mycelium ra- 
 diating from the base of the peridiole. 
 
 ALG2E SEAWEEDS, ETC. 
 
 Order I. RHODOSPERME^E or FLORIDF^E Thal- 
 lus leaflike or filamentous, rose-red or purple. Fructifi- 
 cation consisting of: 1. Spores, mostly inclosed in concep- 
 tacles (ceramidia, coccidia, favellidia, etc.). 2. Tetraspores, 
 red or purple (a membranous sac containing, when ripe, 
 four spores). 3. Antheridia (pellucid sacs filled with 
 yellow corpuscles or spermatozoids). 
 
 Families I. RHODOMELACE^;. Frond cellular, areolated 
 or articulated. Ceramidia external. Tetrapores in rows, 
 immersed in ramuli or contained in proper receptacles 
 (stichidia). 
 
 1. Odonthalia. Frond flattened, linear, with obsolete 
 midrib, pinnatifid, alternately inciso-dentate. 
 
 0. dentata. Color, wine-red. 
 
 2. Rhodomela. Frond cylindric, inarticulate, opaque. 
 Tetraspores in podlike receptacles (stichidia). 
 
 R. lycopodioides. Purplish-brown. 
 R. subfusca. Brownish or reddish. 
 
 3. Bostrychia. Frond cylindric, inarticulate, dotted. 
 The surface-cells quadrate. Tetraspores in terminal pods. 
 
372 THE MICROSCOPIST. 
 
 4. JRytiphlcea. Frond cylindric, inarticulate, trans- 
 versely striate. Tetraspores in podlike receptacles. 
 
 5. Polysiphonia. Frond cylindric, articulate in whole 
 or in part, the branches longitudinally striate. Tetraspores 
 in distorted ramuli. 
 
 6. Dasya. Frond cylindric, the stem inarticulate, ra- 
 muli articulate, composed of a single string of cells. Te- 
 traspores in podlike receptacles (stichidia) borne by the 
 ramuli. 
 
 2. LAURENCIACEJE. Frond cellular, continuous. Cera- 
 midia external. Tetraspores scattered, immersed in the 
 branches and ramuli. 
 
 1. Bonnemaisonia. Frond solid, filiform, rose-red. 
 Much branched ; branches margined with subulate dis- 
 tichous cilia. 
 
 2. Laurenda. Frond solid, cylindric, or compressed 
 (purple or yellowish), pinnatifid. The ramuli blunt. 
 
 3. Chrysim,enia. Frond hollow, filled with mucus, 
 neither constricted nor chambered. 
 
 4. Chylodadia. Branches hollow, filled with mucus, 
 constricted at intervals and chambered. 
 
 3. CORALLINACE^E. Frond calcareous or crustaceous, 
 rigid. Ceramidia external, containing the tetraspores. 
 
 * Frond filiform, articulate. 
 
 1. Corallina. Frond pinnated. Ceramidia terminal, 
 simple. 
 
 2. Jania. Frond dichotomous. Ceramidia tipped with 
 two hornlike ramuli. 
 
 * * Frond crustaceous or foliaceous, opaque, not articu- 
 late. 
 
 3. Melobesia. Frond stony, forming a crustaceous ex- 
 pansion, or a foliaceous or shrublike body. 
 
 4. Hildebrandtia. Frond cartilaginous, not stony. 
 
APPENDIX. 373 
 
 * * * Frond plain, hyaline, composed of cells radiat- 
 ing from a centre. Fructification unknown. 
 
 5. Lithocystis (a minute parasite). L. allmanni forms 
 minute white dots on Chrysimenia clavelosa, consisting of 
 fanshaped fronds composed of square cells. 
 
 4. DELESSERICE^E. Frond cellular, continuous, areolated. 
 Coccidia external. Tctraspores collected into definite 
 clusters (sori). 
 
 1. Delesseria. Frond leafy, of definite form, with per- 
 current midrib. 
 
 2. Nitophyllum. Frond leafy, of indefinite form. No 
 midrib (sometimes vague nerves). 
 
 3. Plocamium. Frond linear or filiform, compressed. 
 Much branched, distichous, ramuli pectinate, secund. 
 
 5. EHODYMENIACEJE. Frond cellular, continuous ; the 
 superficial cells minute. Coccidia external. Tetraspores 
 scattered through the frond or forming undefined, cloud- 
 like patches. 
 
 * Frond flat, expanded, leaflike, dichotomous or pal- 
 mate. 
 
 1. Stenogramme. Conceptades linear, riblike. 
 
 2. Rhodymenia. Conceptades hemispherical, scattered. 
 
 * * Frond compressed or terete, linear or filiform, much 
 branched. 
 
 3. Sphcerococcus. Frond linear, compressed, two-edged, 
 distichously branched, with obscure midrib. 
 
 4. Gradlaria. Frond filiform, compressed or flat, ir- 
 regularly branched ; the central cells very large. 
 
 5. Hypnea. Frond filiform, irregularly branched, 
 traversed by a fibro-cellular axis. 
 
 6. CRYPTONEMIACEJE. Frond fibro-cellular, composed of 
 articulated fibres connected by gelatin. Favellidia im- 
 mersed in the frond or sub-external. letraspores immersed 
 in the frond. 
 
374 THE MICROSCOPIST. 
 
 1. Sub-tribe COCCOARPEJE. Frond solid, dense, cartilagi- 
 nous, or horny. Favellidia in semi-external tubercles or 
 swellings of frond. 
 
 1. Grateloupia. Frond pinnate, flat, narrow, dense, 
 membrano-cartilaginous. Favellidia immersed in the 
 branches, communicating with the surface by a pore. 
 Tetraspores scattered. 
 
 2. Gelidium. Frond pinnate, compressed, narrow, 
 horny. Favellidia immersed in swollen ramuli. Tetra- 
 spores forming subdefined sori in the ramuli. 
 
 3. Gigartina. Frond cartilaginous, cylindric, or com- 
 pressed, its flesh composed of anastomosing filaments 
 lying apart in firm gelatin. Favellidia in external tuber- 
 cles. Tetraspores in dense sori sunk in the frond. 
 
 2. Sub-tribe SPONGIOCARPE^I. 
 
 4. Chondrus. Frond fan-shaped, dichotomously cleft, 
 cartilaginous, dense- Tetraspores in sori immersed in sub- 
 stance of frond. 
 
 5. Phyllophora. Frond stalked, rigid, membranaceous, 
 proliferous from the disk, dense. Tetraspores in distinct 
 superficial sori or in special leafletlike lobes. 
 
 6. Peyssonelia. Frond depressed, expanded, rooting by 
 the under surface, concentrically zoned, membranous or 
 leathery. Tetraspores in superficial warts. 
 
 7. Gymnogongrus. Frond filiform, dichotomous, horny, 
 of dense structure. Tetraspores strung together, contained 
 in superficial wartlike sori. 
 
 8. Polyides. Root scutate. Frond cylindric, dichoto- 
 mous, cartilaginous. Favellaz in spongy external warts. 
 Tetraspores scattered in peripheric stratum of frond, cru- 
 ciate. 
 
 9. Furcellaria. Root branching. Frond cylindric, di- 
 chotomous, cartilaginous. Favellce. unknown. Tetraspores 
 imbedded among filaments of periphery, in swollen pod- 
 like upper branches of frond, transversely zoned. 
 
 3. Sub-tribe GASTROCARPE^E. Frond gelatinously mem- 
 
APPENDIX. 375 
 
 branous or fleshy, often of lax structure internally. Favel- 
 *lidia immersed in central substance of frond, very numerous. 
 
 10. Dumontia. Frond cylindric, tubular, membranous. 
 Tufts of spores attached to wall of tube inside. 
 
 11. Halyme.nia. Frond compressed or flat, gelatino- 
 membranaceous, surfaces separated by a few slender anas- 
 tomosing filaments. Masses of spores attached to inner 
 face of membranous wall. 
 
 12. Ginannia. Frond cylindric, dichotomous, traversed 
 by a fibrous axis, walls membranous. Masses of spores 
 on inner face of wall. 
 
 13. Kallymenia. Frond expanded, leaflike, fleshy-mem- 
 branous, solid, dense. Favellidia like pimples, half im- 
 mersed and scattered. 
 
 14. Iridea. Frond expanded, leaflike, thick, fleshy- 
 leathery, solid, dense. Favellidia wholly immersed, densely 
 crowded. 
 
 15. Catanella. Frond filiform, branched, constricted at 
 intervals into oblong articulations ; the tube filled with 
 lax filaments. 
 
 4. Sub-tribe GLOIOCLADIE^:. Frond loosely gelatinous, 
 the filaments lying apart, surrounded by a copious gela- 
 tin. Favellidia immersed among filaments of periphery. 
 
 16. Cruoria. Frond crustaceous, skinlike. 
 
 17. Naccaria. Frond filiform, solid, cellular; ramuli 
 only composed of radiating free filaments. 
 
 18. Gloiosiphonia. Frond tubular, hollow, walls com- 
 posed of radiating filaments. 
 
 19. Nemaleon. Frond filiform, solid, elastic, filament- 
 ous, axis of a network of anastomosing filaments ; periph- 
 ery of moniliform free filaments. 
 
 20. Dudresnaia. Frond filiform, solid, gelatinous, fila- 
 mentous, axis and periphery like the last. 
 
 21. Cronania. Frond filiform, of a jointed filament, 
 whorled at the joints, with minute multifid, gelatinous 
 ramuli. 
 
376 THE MICROSCOPIST. 
 
 7. CERAMIACE^E. Frond filiform, of an articulated fila- 
 ment, simple, or coated with stratum of small cells. Fa- 
 vellce naked, berrjlike masses. Tetraspores external or 
 partially immersed. 
 
 1. Ptilota. Frond compressed, inarticulate, distichous, 
 pectinato-pinnate. Favellce pedunculate, involucrate. 
 
 2. Microdadia. Frond filiform, inarticulate, dichoto- 
 mous. Favellce sessile, involucrate. 
 
 3. Ceramium. Frond filiform, articulate, dichotomous ; 
 the joints opaque. Favellce sessile, mostly involucrate. 
 Tetraspores mostly immersed. 
 
 4. Spyridia. Frond filiform, inarticulate ; the branches 
 clothed with minute, setiform, articulate ramelli. Favellce 
 pedunculate, involucrate. Tetraspores sessile on the ra- 
 melli. 
 
 5. Griffithsia. Frond articulated, dichotomous, or 
 clothed with whorled, dichotomous ramelli, rose-red. 
 Favellce involucrate, sessile, or pedunculate. Tetraspores 
 sessile, or whorled ramelli. 
 
 6. Wrangelia. Frond articulated, pinnate. Favellce, 
 terminal, involucrate with tufts of pear-shaped spores. 
 Tetraspores sessile, scattered on the ramelli. 
 
 7. Seirospora. Frond articulated. Tetraspores arranged 
 in terminal moniliform strings. 
 
 o 
 
 8. Callithamnion. Frond, at least the branches and ra- 
 muli, articulate, mostly pinnated. Favellce terminal or 
 lateral, sessile without involucre (except in C. turneri). 
 Tetraspores sessile or pedicellate, scattered. 
 
 9. Trentepohlia. Frond articulate, branched, cells in 
 single series. Favellce f in terminal corymbs. 
 
 8. PORPHYRACE^E. Frond plain- and very thin, or tubu- 
 lar and filiform, purplish, with oval spores in sori and 
 tetraspores scattered over the frond. 
 
 1. Porphyra. Frond plain, membranous, very thin, 
 
APPENDIX. 377 
 
 purple ; oval spores in sori, and tetraspores (square) scat- 
 tered over frond. 
 
 2. Bangia. Frond filiform, tubular, composed of radiat- 
 ing cells in transverse rows, in continuous hyaline sheath. 
 
 Order II. MELANOSPORE^E or FUCOIDE^E. Ma- 
 rine. Thallus leaflike, or cordlike, or filamentous. Olive- 
 green or brown. Fructification varied. 1. In Fucacese, mo- 
 ncecious or dioecious conceptacles containing sporanges and 
 antheridia ; the spores being fertilized by spermatozoids 
 after discharge of both from the parent. 2. In Lamina- 
 riacese, etc.. of collections of clavate or filiform sporanges 
 producing zoospores, with antheridia-like Fucacese. 3. In 
 Cutleriacese similar. 4. In Dictyotacese three forms re- 
 sembling Floridese ; tetraspores, sporanges containing sim- 
 ple spores, and antheridia. 
 
 Family L FUCACE.E. Frond leathery or membranous, 
 cellular. Spores and antheridia together or separate in 
 spherical cavities imbedded in the frond. 
 
 * Air-vessels stalked. 
 
 1. Sarpassum. Branches bearing ribbed leaves; air- 
 vessels simple. 
 
 2. Halidrys. Frond linear, pinnate, leafless ; air-ves- 
 sels divided by transverse partitions. 
 
 * * Air-vessels immersed in substance of frond, or 
 absent. 
 
 3. Cytoseira. Root scutate. Frond much branched, 
 bushy. Receptacles cellular. 
 
 4. Pycnophycus. Root branching. Frond cylindric. Re- 
 ceptacles cellular. 
 
 5. Fucus. Root scutate. Frond dichotomous. Recep- 
 tacles filled with mucus, traversed by jointed threads. 
 
 6. Himanthalia. Root scutate. Frond cup-shaped. Re- 
 ceptacles (frondlike) long, strap- shaped, dichomotously 
 branched. 
 
378 THE MICROSCOPIST. 
 
 3. DICTYOTACE^;. -FVowd cellular, flat, compact. Spores, 
 antheridia (and tetraspores ?) in spots or lines (sori) on sur- 
 face. 
 
 1. Haliseris. Frond dichotomous with midrib. 
 
 2. Padina. Frond ribless, fan-shaped, concentrically 
 streaked. Son linear, concentric, bursting through the 
 epiderm. 
 
 3. Zonaria. Frond ribless, lobed, concentrically striate. 
 Sori roundish, with spores and jointed threads. 
 
 4. Taonia. Frond ribless. cleft irregularly, somewhat 
 fan-shaped. Sori linear, concentric, superficial, alternating 
 with scattered spores. 
 
 5. Dietyota. Frond ribless, dichotomous. Sori round- 
 ish, scattered, bursting through epiderm, or (on distinct 
 individuals) scattered spores. 
 
 3. CUTLERIACE^. Frond cellular, compact, ribless. 
 Dotlike collections of sporanges divided into eight com- 
 partments, and antheridia (?) consisting of chambered fila- 
 ments in groups of curved jointed hairs. . 
 
 1. Cutler ia. 
 
 4. LAMINARIACEJE. Frond leathery or gelatinous, cellu- 
 lar. Unilocular sporanges in cloudlike patches, or cover- 
 ing the whole surface of frond ; or multilocular sporanges 
 clothing the whole surface of the frond like an epidermis. 
 
 * Frond stalked, the stalk ending in an expanded leaf- 
 like portion. 
 
 1. Alaria. Leaf membranous, with cartilaginous per- 
 current midrib. 
 
 V. Laminaria. Leaf (simple or cleft) without any 
 midrib. 
 
 * * Frond simple, leafless. 
 
 3. Chorda. Frond cylindric, hollow, the cavity having 
 transverse partitions. 
 
APPENDIX. 379 
 
 5. DICHTYOSIPHONACE^;. Frond cyliiidric, branched, 
 filamentous in structure. Ovoid sporanges imbedded 
 lengthwise in substance of frond, opening by a pore on 
 the surface. 
 
 1. Dictyosiphon. JRoot a minute naked disk. Frond 
 cylindric, branched. Oosporanges irregularly scattered, 
 solitary or in dotlike sori. 
 
 2. Striaria Oosporanges in transverse lines on surface of 
 frond. 
 
 6. PUNCTARIACE.E. Frond cylindric or flat, unbranched, 
 cellular. Ovate sporanges in groups on the surface, inter- 
 mixed with clavate filaments (paraphyses}. 
 
 1. Punctaria. Frond flat and leaflike. Sporanges scat- 
 tered or iii sori. 
 
 2. Asperococcus. Frond membranous, tubular, cylin- 
 dric, or compressed. Sporanges in dotlike sori. 
 
 3. Litosiphon. Frond cartilaginous, filiform, subsolid. 
 Sporanges scattered, almost solitary. 
 
 7. SPOROCHNACE.E. Frond leathery or membranous, 
 cellular, branched. Unilocular or multilocur sporanges at- 
 tached to external jointed filaments, free or collected in 
 knoblike masses. 
 
 * Sporanges on pencilled filaments issuing from the 
 branches (Arthrocladiese). 
 
 1. Demarestia. Frond solid or flat, dichotomously 
 branched. 
 
 2. Arthrodadia. Frond traversed by a jointed tube, 
 filiform, nodose. 
 
 3. Stilophora. Frond filiform, tubular or solid, branched. 
 Sporanges from necklace-shaped filaments in wartlike 
 groups on the frond. 
 
 * * Sporanges in knoblike receptacles composed of 
 whorled filaments (Sporochnese). 
 
 4. Sporochnus. Receptacles lateral on short peduncles. 
 
380 THE MICROSCOPIST. 
 
 5. Carpomitra. Receptacles terminal, at tips of the 
 branches. 
 
 8. CHORDARIACE.E. Frond cartilaginous or gelatinous, 
 of horizontal and vertical filaments (jointed) interlaced. 
 Unilocular sporanges from the base of the vertical fila- 
 ments forming the epiderm of the frond, and multilocular 
 sporanges developed later from filaments surrounding the 
 former. 
 
 1. Chordaria. Axis cartilaginous, dense, filaments of 
 circumference unbranched. 
 
 2. Mesogloia. Axis gelatinous, loose, filaments of cir- 
 cumference branching. 
 
 9. MYRIONEMACE^E. Frond tubelike, crustaceous or 
 spreading as a crust, of filamentous structure. Unilocu- 
 lar and multilocular sporanges attached to the superficial 
 filaments and concealed among them. 
 
 1. Leathesia. Frond tuber- shaped. 
 
 2. Ralfsia. Frond crustaceous. 
 
 3. Elachistea. Frond parasitic, of a tubular base, bear- 
 ing pencilled erect filaments. 
 
 4. Myrionema. Frond parasitic, forming a flat base, 
 bearing cushionlike tufts of decumbent filaments. 
 
 10. ECTOCARPACE^I. Frond filiform, jointed. Unilocu- 
 lar sporanges, ovate sacs at ends or intermediate joints of 
 the filaments and multilocular sporanges of minute jointed 
 filaments in similar situations. Antheridia with spermato- 
 zoids in Sphacelaria. 
 
 * Frond rigid, each articulation of numerous cells 
 (Sphacelariew). 
 
 1. Cladostephus. Ramuli whorled. 
 
 2. Sphacelaria. Ramuli distichous, primated. 
 
 * * Frond flaccid, each articulation of a single cell. 
 
 3. Ectocarpus. Frond branching, ramuli scattered. 
 
APPENDIX. 381 
 
 4. Myriotrichia. Frond unbranched, ramuli whorl ed, 
 tipped with pellucid fibres. 
 
 Order III. CHLOROSPORE^E or CO^FERVOIDE^E. 
 In sea or fresh water, or on damp surfaces, with fila- 
 mentous, or more rarely a leaflike thallus; microscopic 
 forms, sometimes pulverulent or gelatinous, consisting fre- 
 quently of definitely arranged groups of distinct cells, 
 with an ordinary structure, or with their membrane silici- 
 fied (Diatomacese). Fructification varied. 
 
 1. Resting spores produced from cell-contents after fer- 
 tilization either by conjugation or impregnation. 
 
 2. Spermatozoids produced from the contents of other 
 cells. 
 
 3. Zoospores. Two, four or multiciliated active gonidia, 
 discharged from the vegetative cells without impregna- 
 tion and germinating directly. 
 
 The simple vegetative increase of unicellular forms is 
 analogous to cell division of filamentous forms. 
 
 The Volvocinese pass the vegetative stage of existence 
 as ciliated zoospores collected within a gelatinous com- 
 mon envelope. 
 
 Family I. LEMANE^;. Frond cartilaginous, leathery, 
 inarticulate, filamentous, hollow, with whorls of wans 
 at irregular distances, or necklace-shaped. Fructification 
 tufted, simple, or branched ; necklace-shaped filaments, at- 
 tached to inner surface of tubular frond, and breaking up 
 into elliptic spores. G row in fresh water. 
 
 1. Lemania. Two species, L. torulosa and L.flumatttis, 
 in clear running streams. 
 
 2. BATBACHOSPERM&B. Plants filamentous, articulated, 
 invested with gelatin. Frond of aggregated, articulate, 
 longitudinal cells, whorled at intervals, with short, hori- 
 zontal, cylindric, or beaded, jointed ramuli. Fructification 
 
382 THE MICROSCOPIST. 
 
 ovate spores, and tufts of antheridial cells (?) attached to 
 the lateral ramuli, which consist of minute, radiating, 
 dichotomous, beaded filaments. Fresh-water plants. 
 
 1. Batrachospermum. Lateral whorled ramuli, beaded 
 spores in globular knobs in the whorls. 
 
 1. B. moniliform. Color various, vaguely branched. 
 
 2. B. giganteum. Large, purple when dry, long, bifur- 
 cated branches. 
 
 3. B. affine. 
 
 4. B. cosrulescens. ^Eruginous, slender, branched. 
 Upper and lower whorls confluent. 
 
 5. B. vagwn. Dichotomously branched, equally thick 
 throughout ; whorls all confluent. 
 
 2. T/wrea. Stems continuous, whorled, articulated, 
 sometimes branched, ramuli cylindric, the spores at their 
 
 3. CH^ITOPHORACEJE. In the sea or fresh water, coated 
 by gelatinous substance, either filiform or (connected fila- 
 ments) gelatinous, definitely formed or shapeless fronds 
 or masses. Filaments jointed, bearing bristlelike pro- 
 cesses. Fructification, zoospores from cell-contents of fila- 
 ments, resting spores from particular cells after impregna- 
 tion by ciliated spermatozoids produced in antheridial cells. 
 
 1. Draparnaldia. Filaments free, primar}^ nearly color- 
 less, with tufts of colored ramuli at the joints ; zoospores 
 formed singly in the joints of the ramuli. 
 
 2. Chtftophora. Filaments dichotomously branched, 
 aggregated into shapeless, incrusted or branched, gelati- 
 nous fronds, the joints bearing bristlelike branches. 
 Zoospores (four cilia) solitary in the articulations, mem- 
 branes of filaments very fugacious. (Little green protu- 
 berances on sticks, etc., in fresh water.) 
 
 C. endivicefolia. C. tuberculosa. C. elegans. C..pisiformis. 
 C. dilatata. C. long&va. 
 
 3. Coleochcete. Frond disk-shaped or irregularly ex- 
 
APPENDIX. 383 
 
 panded, adherent to leaves, etc., of aquatic plants, formed 
 of jointed dichotornous filaments radiating from a centre, 
 more or less conjoin ted laterally, joints producing from 
 the back a slender truncate open tube from which a long 
 bristle is exserted. Spores and zoospores formed in the 
 joints. 
 
 4. Ochlochcete. Frond discoid, appressed, filaments cyl- 
 indric, radiating, irregularly branched, of a single series 
 of cells, each of which is prolonged above into an inar- 
 ticulate bristle. 0. kystrix. 
 
 4. COXFERVACE^E. In sea or fresh water, filamentous, 
 jointed, without evident gelatin. Filaments variable, sim- 
 ple or branched, cells more or less tilled with green, or 
 rarely brown or purple, granular matter, sometimes ar- 
 ranged in peculiar patterns on the walls, and convertible 
 into spores or zoospores. Not conjugating. 
 
 1. Cladophora. Filaments tufted, much branched. Sea 
 and fresh water. Zoospores minute, many in a cell. 
 
 C. cepagropila. Dense balls in lakes, etc. 
 C. crispata. Yellowish or dull-green strata. 
 
 2. Rhizoclonium. Filaments decumbent, with small 
 rootlike branches. Zoospores minute, numerous. Sea, 
 brackish, and fresh water. 
 
 R. rivulare. Filaments simple. Bright-green bundles, 
 two to three feet long, in streams. 
 R. tortuosum. In salt-water pools. 
 R. arenosum. Dirty-green strata, on sandy seashores. 
 R. obtusangulum. Sandy, seashores. 
 R. riparium. 
 
 R. implexum. On mountain rocks. 
 R. arenicolum (ditto). 
 
 3. Conferva. Filaments unbranched. Zoospores minute, 
 numerous in the cells. Sea, brackish, and fresh water. 
 
 C. bombydna. Yellow-green cloudy stratum in stagnant 
 water. 
 
384 THE MICROSCOPIST. 
 
 C.floccosa. More robust, articulations once or twice 
 longer than broad. 
 
 C. cerea. Yellow-green tufted filaments, thick as hog's 
 bristles. 
 
 C. melagonium. Erect tufted filaments. 
 
 C. linum. Long, tangled filaments. 
 
 4. Ulothrix (?). Filaments simple, often fasciculated, 
 joints short. Zoospores four ciliated ; two, four, or more 
 in a cell. Fresh water. 
 
 5. Stigeodonium (?). Filaments branched, ramules run- 
 ning out into slender points, cell-walls often dissolving to 
 emit zoospores. Zoospores four ciliated, one in a cell. 
 
 5. ZYGNEMACE^:. Fresh-water filaments, no evident 
 gelatin, of a series of cylindric cells, straight or curved. 
 Cell-contents often arranged in elegant patterns on the 
 walls. Reproduction from conjugation followed by a true 
 spore, in some genera dividing into four sporules. 
 
 1. Zygnema. Filaments simple, green contents ar- 
 ranged in two globular or stellate masses in each cell. 
 Conjugate by transverse processes. Spores in a parent 
 cell on cross branch. 
 
 * Spores in one of paren.t cells. 
 Z. crudata. Spores globose. 
 
 Z. stagnalis. 
 Z. insignis. 
 Z. bicornis. 
 
 * * Spores in cross branches. 
 Z. iminersa. 
 
 Z. conspicua. 
 Z. decussata. 
 Z. Ealfsii. 
 Z. pectinata. 
 
 2. Spirogyra. Filaments simple, green contents in one 
 or more spiral bands on cell-wall. Conjugate by trans- 
 
APPENDIX. 385 
 
 verse processes. Spores in one of parent- cells (or occa- 
 sionally in both). 
 
 * Spiral band single. 
 
 S. tenuissima. S. longata. S. inflata. S. communis. S. 
 quinina. 
 
 * * Spirals two. 
 
 S. decemina. S. elongata. 
 
 * * * Spirals numerous. 
 
 S. nitida. S. maxima. S. bellis. S. pellucida. S. rivu- 
 laris. S. curvaia. 
 
 3. Zygogonium. Filaments simple or slightly branched ; 
 contents diffused or in two transverse bands. Conjugate 
 by transverse processes. Spores globose, in cross branches, 
 or in blind lateral pouches without conjugation. Z. 
 ericetorum. 
 
 4. Mesocarpus. Filaments simple, with contents dif- 
 fused. Conjugate by transverse processes, from which the 
 filaments become recurved. Spores in cross branches. 
 
 J/. scalaris. M. depress us. 
 
 5. Staurocarpus. Filaments simple, contents diffused 
 (rarely in moniliform lines). Conjugate by transverse pro- 
 cesses, from which the filaments become recurved. Spores 
 (or sporanges) square or cruciate in dilated cross branches. 
 
 5. glutinosus. S. cczrulescens. S. quadratus. S. virescens. 
 S. gradllimus. S. gracilis. 
 
 6. Mougeotia. Filaments simple, soon bent at intervals ; 
 contents mostly diffused, sometimes in several serpentine 
 lines. Conjugate by the inosculation of filaments at the 
 convexity of the angles. Spores not known. M. genuflexa. 
 
 6. (EDOGONIACEJE. Simple or branched, fresh-water 
 filamentous plants, attached, without gelatin. Cell-con- 
 tents uniform, dense. Cell-division accompanied by cir- 
 cumcissile dehiscence of parent-cell, producing rings on 
 the filaments. Reproduction by zoospores from contents 
 of a cell, with a crown of cilia ; resting spores in sporan- 
 
 25 
 
386 THE MICROSCOPIST. 
 
 gial cells after fecundation by ciliated spermatozoids 
 formed in antheridial cells. 
 
 1. (Edogonium. Filaments unbranched. 
 
 * Spores globular. 
 
 f Sporanges with valvular lid. 
 (E. rostellatum. Monoecious, 
 f f Spo ranges with lateral orifice. 
 Monoecious. 
 
 (E. curvun. (E. tumidulum. 
 ;f Gynandrosporous. 
 
 (E. Rothii. (E. depressum. (E. Braunil (E. echino- 
 spermum. 
 
 * * Spores oval. 
 
 f Spo ranges with valvular lid. 
 
 Gynandrosporous. 
 
 (E. dliatum. 
 
 f f Sporanges with lateral orifice. 
 
 J Gynandrosporous. 
 
 (E. apophysatum. 
 
 $ % Dioecious. 
 
 (E. gemelliparum. 
 
 2. Bidbochceta. Filaments branched and bearing bristle- 
 cells with a bulbous base. 
 
 7. SIPHONACE.E. Sea, fresh water, or on damp ground. 
 Membranous or horny hyaline substance, filled with green 
 (in Saprolegniese colorless) granular matter. Fronds con- 
 tinuous tubular filaments, free, or in spongy masses of 
 various shapes, crustaceous, globular, cylindric, or flat. 
 Zoospores single or numerous. Resting spores in spor- 
 angial cells after impregnation by contents of antheridial 
 cells of different form. 
 
 1. Codium. Filaments green, branched, interwoven into 
 spongiform frond, producing biciliated zoospores in spor- 
 angial cells borne on the sides of the erect clavate branches. 
 Marine. 
 
APPENDIX. 387 
 
 2. B-yopsis. Filamentsgreen, free,primately branched ; 
 two or four ciliated zoospores in extremities of branches. 
 Marine. B. plumosa. B. hypnoides. 
 
 3. Vaucheria. Filaments green, more or less branched, 
 continuous, producing in apices large solitary zoospores 
 covered with cilia, also bearing lateral, globose, sporangial 
 cells and hooklike antheridial cells (" horns "). Marine 
 or aquatic or on damp ground. 
 
 4. Botrydium. Frond a spherical green vesicle on a 
 ramified filamentous base, the cavity of the whole con- 
 tinuous, the ramified base producing new vesicles (spor- 
 anges) by stoloniferous growth. Multiplied by granular 
 contents of vesicle discharged by rupture at the summit. 
 Damp grounds. 
 
 5. Hydrodictyon. Frond a green baglike net, with 
 usually pentagonal open meshes, formed of cylindric cells 
 connected by their ends. Ciliated zoospores formed in 
 the " link "-cells, uniting and forming a miniature net be- 
 fore escaping from parent-cell. 
 
 6. Achyla. Filaments colorless or light brownish (like 
 mycelia of fungi; ; free, slightly branched. Numerous 
 zoospores in apices of filaments, and spores in globose 
 lateral sporangial cells. On dead flies, fishes, or sometimes 
 on decaying vegetable matter in water. A. prolifera. 
 
 8. OSCILLATORIACE.E. Sea, fresh water, or damp ground. 
 Gelatinous and filamentous. Filaments slender, tubular, 
 continuous, filled with colored, granular, transversely 
 striate substance, seldom branched, though often coher- 
 ing so as to appear branched ; usually massed in broad 
 floating or sessile strata ; very gelatinous ; occasionally 
 erect and tufted. More rarely in radiating series bound 
 by firm gelatin, and then forming globose, lobed, or flat 
 crustaceous fronds. Contents separate into roundish or 
 lenticular gonidia. 
 
 * In fresh water or damp earth. 
 
388 THE MICROSCOPIST. 
 
 a. Stratum ceruginous or blue-green. 
 
 0. limosa. 0. tenius. 0. musconim. 0. turfosa. 0. 
 decor ticans. 
 
 b. Stratum dull green inclining to purple, black, or 
 brown. 
 
 0. nigra. 0. autumnalis. 0. cortexta. 0. ochracea. 
 * * Marine or in brackish water. 
 
 0. littoralis. 
 
 The above are species of Oscillatoria. 
 
 A. OSCILLATORIE^:. Filaments transversely striate or 
 moniliform, sometimes spirally curled, sheathed, or in the 
 minute forms without evident sheaths. Spontaneous 
 oscillating, creeping, or serpentine motion. Increase by 
 transverse division. 
 
 1. Bacterium. Filaments colorless, very small, short, 
 wand-shaped, or longish-oval, with two ' to four cross 
 striae, exhibiting vibratory motion. 
 
 2. Vibrio. Filaments colorless, very slender, monili- 
 form. Active serpentine motion. 
 
 3. Spirulina. Filaments green, very slender, continu- 
 ous or moniliform, curled into a long helical or screw 
 form ; oscillating. 
 
 4. Didymohdix. Filaments brown, very slender, con- 
 tinuous, curled spirally and twisted in pairs. 
 
 5. Oscillatoria. Filaments colored, continuous, trans- 
 versely striated, readily breaking across ; a proper cellu- 
 lar sheath ; oscillating ; in strata imbedded in gelatin. 
 
 6. Microcoleus. Filaments as in 5, but in bundles in a 
 common gelatinous sheath, tubular and dichotomously 
 branched. Filaments oscillating. 
 
 7. C&nocoleus. Filaments branched, contained in a 
 tough, more or less permanent sheath, which bursts ir- 
 regularly. Filaments annulated. 
 
 8. Symploca. Filaments as in 5, but erect and tufted, 
 coherent at base, bristling above. 
 
APPENDIX. 389 
 
 B. LYNGBYE.E. Filaments motionless (?), oscillarioid, 
 inclosed in distinct sheath, tufted or forming strata, with 
 or without enveloping jelly. 
 
 9. Dasyglwa. Filaments unbranched. Older sheaths 
 broad, coalescent outside in amorphous gelatinous stratum. 
 
 10. Lyngbya. Filaments elongated, articulated, un- 
 branched ; distinct convoluted cellulose tube ; no gelatin- 
 ous matrix ; articulations close. 
 
 11. Leibleinia. Filaments short, erect, tufted, un- 
 branched ; distinct cellulose coat ; free ; no jelly. 
 
 C. S07TONEME2B. Filaments articulated, simple, or 
 branched, motionless; distinct articulations and large in- 
 terstitial (propagative?) cells; sheaths soften and swell, 
 but no gelatinous matrix. 
 
 12. Scytonema. Filaments caespitose, or, more rarely, 
 fasciculate; a double (lamellar) gelatinous sheath, mostly 
 closed at apex; branches continuous by lateral growing 
 out of primary filaments, with kueelike base. 
 
 13. Desmonema. Filaments branched, more or less co- 
 herent ; primary branches with connecting cell at base ; 
 secondary branches without cell, annulated. 
 
 14. Arthronema. Filaments articulated, simple, in short 
 lengths, overlapping at their ends in gelatinous sheath. 
 
 15. Petalonema. Filaments branched ; outer sheaths of 
 joints expanded upwards and outwards into funnel-shaped 
 bodies, each partly overlapping its successor, forming a 
 common obliquely lamellated and transversely barred 
 gelatinous cylinder. 
 
 16. Calothrix. Filaments closely articulated, tufted, 
 with branches in apposition for some distance, here and 
 there cohering laterally; sheaths firm, often dark-colored. 
 
 17. Tolypothrix. Filaments free, radiantly or fastigi- 
 ately branched, distinctly articulated at bases of branches, 
 which are continuous by ex-current, not in apposition ; 
 sheaths thin, hyaline. 
 
390 THE MICROSCOPIST. 
 
 18. Sirosiphon. Filaments single, double, or triple, in 
 distinct common sheath, articulated, branched by lateral 
 budding ; branches divergent. 
 
 19. Schizothrix. Filaments branched by division ; 
 sheaths lamellated, thick, rigid, curled, thickened below, 
 finally longitudinally divided. 
 
 20. Symphyosiphon. Filaments erect or ascending, in- 
 closed in lamellated hard sheaths, concreted laterally at 
 their bases, involved in jelly. 
 
 21. Rhizonema. Sheath cellular, with branched and 
 anastomosing rootlets (?) ; filaments annulated, inter- 
 rupted here and there by a connecting cell ; branches in 
 pairs from protrusion of filament. 
 
 D. RIVULARIEJS. Filaments articulated ; enlarged basal 
 cell, attenuated above, connected into definite or indefinite 
 fronds ; motionless. 
 
 22. Schizosiphon. Basal cells globose; filaments simple, 
 sheathed; sheaths in groups, dark-colored, hard, open, 
 and expanded above, and overlapping so as to form a 
 succession of ochrere, which have the free borders slit up 
 into filaments or fringes ; also displaying a spiral struc- 
 ture in dissolution. 
 
 23. Physactis. Filaments whip-shaped, torulose at base ; 
 sheaths simple, gelatinous, in a globose and solid, or sub- 
 sequently a bullose, vesicular frond ; in globose fronds 
 filaments radiate from centre, in vesicular from internal 
 (lower) surface of gelatinous matrix. 
 
 24. Ainactis. Filaments branched, articulate ; thin 
 sheaths in solid pulvinate frond, which is concentrically 
 zoned by the dichotomous branching of filaments ; sheaths 
 more or less solidified by carbonate of lime ; sometimes a 
 spiral structure in dissolution. 
 
 25. Rivularia. Filaments witli an oval basal cell, suc- 
 ceeded by a cvlindric manubrium, the remainder short, 
 attenuated upwards (whip-shaped) ; sheaths sometimes 
 
APPENDIX. 391 
 
 saccate below, open (not fringed) above, forming a slippery 
 gelatinous frond. 
 
 26. E metis. Filaments whip- shaped, with repeated 
 ochreate sheaths, forming fronds in which they radiate, 
 and by superposition of successive generations form con- 
 centric layers ; the ochreate sheaths are cartilaginous, 
 lamellated, united laterally, funnel-shaped, fringed at open 
 edge. 
 
 27. Inomeria. Filaments whip-shaped, vertical, paral- 
 lel ; obscure sheaths decomposed into slender filaments, 
 forming crustaceous fronds, becoming stony. 
 
 28. Petronema. Densely csespitose, erect, somewhat 
 regularly branched ; branches free, with obtuse rounded 
 apices, and each with connecting cell at base ; filaments 
 annulated and growing thicker upwards. 
 
 E. LEPTOTHRICE^:. Doubtful Oscillatoriaceae. 
 
 29. Leptothrix. Filaments very slender, neither articu- 
 lated, branched, concreted, nor sheathed. 
 
 30. Hypheothrix. Filaments unbranched, inarticulate, 
 sheathed, interwoven in more or less compact stratum. 
 
 31. Kymploca. Filaments unbranched, sheathed, inar- 
 ticulate, concreted into branches, conjoined at their bases; 
 sheath a simple hyaline membrane. 
 
 9. NOSTOCHACE.E. Gelatinous Fresh water, or in damp 
 mosses, etc. ; soft, or almost leathery, of variously curled 
 or twisted necklace-shaped filaments, colorless or green, 
 composed of simple (or double) rows of cells, contained in 
 a gelatinous matrix of definite form, or heaped without 
 order in a gelatinous mass. Some cells enlarge and form 
 vesicular empty cells or sporangial cells ; reproduce by 
 breaking up the filaments, and, by resting spores formed 
 singly in the sporanges. 
 
 1. Nostoc. Phycoma, or general mass of plant in a film 
 formed by condensation of the surface ; globose, or spread 
 
392 THE MICROSCOPIST. 
 
 out ; form variable, gelatinous or mucous, coriaceous, soft 
 or hard, elastic, slimy, containing simple, curved, and en- 
 tangled moniliform colorless or greenish filaments, com- 
 posed of cells, which seem solid, imbedded in amorphous 
 gelatinous matrix ; heterocysts globose, interstitial, larger 
 than ordinary joints of filaments. 
 
 N. commune. N. cceruleum. N. verruconum. N. minat- 
 issimum. N. lichenoides. N. vesicarium. N. sphcericum. 
 N. pruniforme. N.foUacum. 
 
 2. Monormia. Frond or phycoma definite, gelatinous, 
 elongated, linear ; spirally curled and convoluted sheath, 
 inclosing a single moniliform filament ; heterocysts inter- 
 stitial ; sporanges from joints most distant from vesicular 
 cells. M. intricata. 
 
 3. Anabaina. Filaments moniliform or cylindric, often 
 curled, in formless mucous matrix, often forming a float- 
 ing film, with vesicular cells (heterocysts) and sporangial 
 cells. 
 
 * Without a membranous sheath. 
 
 a. Trichormus. Heterocysts interstitial and terminal ; 
 sporanges first from cells most distant from heterocysts. 
 
 b. Sphwrozyga. Heterocysts interstitial ; sporanges 
 from nearest cells. 
 
 c. Cylindrospermum. Heterocysts terminal ; sporanges 
 as last. 
 
 d. Dolichosperm um. Heterocysts interstitial ; sporanges 
 indefinite and unequal. 
 
 * * Filaments not included in membranous sheath. 
 
 e. Aphanizomenon. Heterocysts none (?) ; sporanges 
 usually simple and unequal. 
 
 f. Sperm.osim. Heterocysts interstitial, single or in 
 pairs ; sporanges as in Trichormus. 
 
 10. ULVACE^;. Marine or fresh-water Algae, membra- 
 nous, flat, and expanded ; tubular or saccate fronds, com- 
 posed of polygonal cells firmly conjoined by their sides ; 
 
APPENDIX. 393 
 
 zoospores formed from cell-contents and breaking out from 
 the surface, or motionless spores from the whole contents 
 of a cell. 
 
 1. Ulva. Frond plane, simple, or lobed, of double layer 
 of cells, closely packed, producing zoospores. U. lactuca. 
 (latissima) U. Linza. 
 
 2. Enter omorphi. Frond hollow, simple, or branched, 
 of a single layer of cells, closely packed, forming a sac or 
 tube, with zoospores. E. intestinalis. 
 
 3. Monostroma. Frond flat or saccate, simple or lacer- 
 ate-lobed, forming a single layer of cells, which are scat- 
 tered in a homogeneous membrane, with zoospores. M. 
 bullosum. 
 
 4. Prasiola. Frond membranous, lacerate-lobed, of sin- 
 gle layer of cells in simple or compound lines, or groups 
 multiple of four ; spores from whole contents of cells, mo- 
 tionless. P. callophylla, crispa,furfuracea^ and stipitata. 
 
 5. Schizogonium. Frond filiform, dilated here and there 
 into flat ribands, with two or four rows of cells ; spores 
 from whole contents, motionless. S. percursum. S. l&te- 
 vireus. S. murale. 
 
 11. PALMELLACE^;. Plants forming gelatinous or pul- 
 verulent crusts on damp surfaces of stone, wood, etc. 
 Masses of gelatinous substance, or pseudo-membranous 
 expansions or fronds, of flat, globular, or tubular form, of 
 one or numerous cells, with green, red, or yellowish con- 
 tents ; spherical or elliptical form, the simplest being iso- 
 lated cells (in groups of two, four, eight, etc.) ; others 
 formed of some multiple of four, the highest of compact, 
 numerous, more or less closely conjoined cells. Reproduce 
 by cell-division, by conversion of cell-contents into zoo- 
 spores, and, by resting spores formed sometimes after 
 conjugation, in other cases probably after fecundation by 
 spermatozoids. 
 
394 THE MICROSCOPIST. 
 
 * Plants with a frond of colorless gelatinous substance, 
 f Frond amorphous. 
 
 1. Palmella. Frond a slimy stratum, crowded with 
 large globular cells, multiplying by division ; green and 
 red. P. cruenta. 
 
 2. Microhaloa. Frond mucoid, floating in water, 
 crowded with minute cells, multiplying by division ; 
 oreen and red. 
 
 O 
 
 f f Frond definite. 
 
 3. Glceocarpus. Frond of cells in wade gelatinous coats, 
 inclosed in similar coats of parent-cells for several genera- 
 tions. 
 
 4. Botrydina. Frond globose, the periphery of cells co- 
 hering into a sort of cellular epiderm, the inner cells free. 
 
 5. Clathrocystis. Frond gelatinous, first globose, then 
 hollow, then broken by irregular expansion into a coarse 
 net, finally breaking up; frond crowded with minute cells, 
 multiplied by division. 
 
 6. Coccochloris. Frond globose, gelatinous, containing 
 numerous distinct cells, all free. 
 
 7. Merismop&dia. Frond very minute, flat, square, ge- 
 latinous ; cells in families of four, sixteen, and sixty-four. 
 
 8. Urococcus. Frond of streaked gelatinous tubes, 
 formed of ensheathing parent-cell membrane in a single 
 row, with cells solitary or binary (from division) in ends 
 of the tubes. 
 
 9. Hormospora. Frond a wide, gelatinous, simple, or 
 branched sheath, with single row of cells in twos or fours. 
 
 10. Tetraspora. Frond gelatinous, more or less foliace- 
 ous ; cells in fours, ultimately becoming free as zoospores. 
 
 11. Hydrurus. Frond toughly gelatinous, filiform, with 
 imbedded longitudinal rows of cells. 
 
 12. Palmodictyon. Frond gelatinous, filiform, branched ; 
 branches dividing and anastomosing into a net, consisting 
 of large vesicular cells with colored contents, which escape 
 as zoospores. 
 
APPENDIX. 395 
 
 * * Plants of single cells, solitary, or united in small 
 numbers into families. (Unicellular Algse.) 
 f Solitary cells. 
 
 13. Schizochlamys. Cells free, globular, aggregated in 
 jelly, each dividing into two or four, set free by parent- 
 cell breaking into two or four segments ; green. 
 
 14. Chlorosphwra. Unicellular, free ; a large globose 
 cell with green contents, dividing into two, in each of 
 which is formed a new cell like the parent, set free by 
 lateral rupture of parent-cell membranes. 
 
 15. Charaeium. Unicellular ; a minute, attached, pyri- 
 form, fusiform, or subglobose sac, shortly stipitate, con- 
 taining green protoplasm, which by oft-repeated binary 
 division forms a swarm of active two-ciliated zoospores, 
 escaping by a lateral or terminal slit. 
 
 16. Apiocystis. Simple attached sac with stout mem- 
 brane ; green contents ; at first groups of four still go- 
 nidia, which subdivide repeatedly, and as the parent-sac 
 grows become active zoospores, which move in parent-sac, 
 and then break out in a swarm. 
 
 17. Codiolum,. Attached, small, long, clavate sac, at- 
 tenuated below into a solid stipe, tilled with granular 
 green contents and starch granules, ultimately converted 
 at once into many gonidia, escaping by rupture of apex ; 
 gonidia globose. 
 
 18. Hydrocytium. Attached minute oblong sac ; short 
 hyaline stalk ; green contents ; parietal starch-corpuscle ; 
 contents divided at once into many two-ciliated zoospores, 
 lying on the wall, then moving actively and breaking out 
 into a swarm. 
 
 19. Ophiocytium. Minute, elongated, cylindric, curved 
 sac ; short stipe ; free or attached ; green contents scat- 
 tered ; finally eight gonidia in a single row, set free by 
 circumcissile rupture of end of sac. 
 
 20. Sciadium. First a minute, solitary, attached, elon- 
 gate, tubular, stipitate sac, with eight gonidia in single 
 
396 THE MICROSCOPIST. 
 
 row ; apex of sac opens by circumcision, and the gonidia 
 grow out into tubes like the parent in an umbel, their 
 stipes remaining inserted ; each new tube repeats this to 
 fourth or more generation, the last generation from the 
 compound umbel emitting its gonidia as two-ciliated zoo- 
 spores. 
 
 21. Ckytridium. Parasitic; minute globular pyriform 
 or urceolate sac, attached by a foot which penetrates into 
 the supporting body (mostly a Confervoid) ; cell-contents 
 colorless, becoming two-ciliated zoospores, escaping by 
 dehiscence of a valvelike lid, or by simple rupture of sac. 
 
 22. Pythium. Parasitic ; a globular sac in the interior 
 of cell of diseased Confervoids, often in groups ; contents 
 colorless ; sac grows to flasklike form, the neck perforat- 
 ing the wall of the nurse-plant and bursting to emit ac- 
 tive gonidia (?). 
 
 12. VOLVOCINE.E. Microscopic, cellular; fresh-water 
 groups of bodies, like zoospores, connected into four by 
 enveloping membranes ; either assemblages of coated zoo- 
 spores by cohering membranes, or of naked zoospores in 
 a common membrane; the zoospore-like two-ciliated bodies 
 perforate the coat, and by conjoined action move the entire 
 group; reproduce by division (Gonium}, or by single cells 
 becoming families (Pandorina^ Volvox), and, by resting 
 spores, formed after impregnation of some cells by sperma- 
 tozoids formed from contents of other cells. 
 
 Solitary : 
 
 No cilia, Gyges. 
 
 A pair of cilia, PROTOCOCCUS. 
 
 Grouped : 
 
 Square layer, gonidia of 2 cilia, GONIUM. 
 
APPENDIX. 397 
 
 Forming a spherical body : 
 Cilium solitary. 
 With a tail, Uroglena. 
 Without a tail. 
 Without eye-spot. 
 With special coats, Syncrypta. 
 With eye-spot. 
 
 Goniclia dividing into clusters, Spharosira. 
 Cilia 2. 
 
 No eye-spot, Synura. 
 With eye-spot. 
 Common envelope spherical. 
 Gonidia numerous, all over periphery, VOL vox. 
 Gonidia 8, in a circle at the equator, STEPHANOSPH.ERA. 
 Envelope ellipsoidal, gonidia 16 or 32, perhaps stages 
 of Yolvox or Pandorina. 
 
 13. DESMIDIACE^E. Microscopic, gelatinous, green; cells 
 without siliceous coat; forms varied, as oval, crescentic, 
 cylindric, etc., with a more or less stellate appearance, 
 having a bilateral symmetry, the junction being marked 
 by a division of the green contents ; individual cells free 
 or grouped. Reproduction by division and by resting 
 spores produced in sporangia formed after conjugation of 
 two cells and union of their contents, and by zoospores 
 formed in the vegetative cells or in the germinating rest- 
 ing spores. 
 
 I. CLOSTERIE^. Cells single, elongated, never spinous, 
 often not constricted in the middle ; sporangia smooth. 
 
 1. Closterium. Cell crescent-shaped, or much attenu- 
 ated at the ends, not constricted in the middle. 
 
 2. Penium Cell straight, not, or very little constricted 
 in the middle, rounded at both ends. 
 
 3. Tetmemorus. Cell straight, constricted, notched at 
 ends. 
 
398 THE MICROSCOPIST. 
 
 \ 
 
 4. Docidium. Cell straight, constricted, truncate at 
 ends. 
 
 5. Spirotcenia. Cell straight, not constricted ; endo- 
 chrome spiral. 
 
 IT. COSMARIE^:. Cells single, distinctly constricted in 
 the middle ; segments seldom longer than broad; sporan- 
 gia spinous or tuberculated. 
 
 6. Micrasterias. Lobes of the segments incised or bi- 
 dentate. 
 
 7. Euastrwn. Segments sinuated, generally notched at 
 ends, and with inflated protuberances. 
 
 8. Cosmarium, Segments neither notched nor sinuated, 
 end view elliptic, circular, or cruciform. 
 
 9. Xanthidiam. Segments compressed, entire, spinous. 
 
 10. Arthrodesmus. Segments compressed, each with 
 only two spines. 
 
 11. Staurastrum. End view angular, radiate, or with 
 elongated processes which are never in pairs. 
 
 12. Didymodadon. End view angular, each angle with 
 two processes, one inferior and parallel with that of other 
 segment, the other superior and divergent. 
 
 III. DESMIDIE.E. Cells united into an elongated jointed 
 filament ; sporangia spherical, smooth. 
 
 13. Hyalotheca. Filament cylindric. 
 
 14. Didymoprium. Filament cylindric or subcylindric ; 
 cells with two opposite bidentate projections. 
 
 15. Desmidium. Filament triangular or quadrangular ; 
 cells with two opposite bidentate projections. 
 
 16. Aptogonum. Filament triangular or plane, with 
 foramina between the joints. 
 
 17. Spk&rozosma. Filament plane; margins incised or 
 sinuate ; joints with junction glands. 
 
APPENDIX. 399 
 
 IV. ANKISTRODESMIJE. ^- Cells elongate, entire, small, 
 grouped in fagot-like bundles. 
 
 18. Ankistrodesmus. 
 
 V. PEDIASTRE.E.- Cells grouped in the form of a disk 
 or star, or placed side by side in one or two short rows. 
 
 19. Pediastrum. Cells forming a disk or star, marginal 
 cells bidentate. 
 
 20. Monactinus. Cells as in 19, but marginal cells uni- 
 dentate. 
 
 21. Scenedesmus. Cells placed side by side in one or 
 two rows. 
 
 14. DIATOMACE^:. For genera, see page 142. 
 
INDEX AND GLOSSARY 
 
 OF TERMS USED IN THE MICROSCOPIC SCIENCES. 
 
 The figures refer to the page. 
 
 Aberration, 22 (Lat. ab, from, and erro, to wander). Errors 
 resulting from imperfection of lenses. 
 
 Aberrant. Differing from customary structure. 
 
 Abnormal (Lat. ab, and norma, a rule). Contrary to usual 
 structure. 
 
 Abiogenesis, 125 (Gr. a, privative ; bios, life; and gennao, to 
 produce). Spontaneous generation, or production without pre- 
 existing life. 
 
 Absorption Bands, 18, 45, 101. Lines, more or less distinct, 
 produced in the spectrum by certain transparent substances. 
 
 Abranchiate (Gr. a, without ; bragchia, gills). 
 
 Acalephs, 166 (Gr. akalephe, a nettle). Sea nettles, or jelly- 
 fish. Their power of stinging is caused by microscopic thread- 
 cells in the integument. 
 
 Acanthocephali, 335 (Gr. akantha, a spine, and kephale, a 
 head). An order of parasitic worms. 
 
 Acanthaceae. A natural order of plants. The seeds of many 
 genera have hygroscopic hairs with spiral fibres, which make 
 them interesting microscopic objects. 
 
 Acarinse, 179, 338 (Gr. akari, a mite). An order of the 
 Arachnidae, of which the cheese-mite is the type. 
 
 Acephalocyst (Gr. a, kephale, kustis, a headless bladder). 
 Simple sacs filled with transparent liquid, usually known as 
 hydatids. They are the cysts of Echinococci, in which the 
 animals have disappeared or have been overlooked. 
 
 26 
 
402 INDEX AND GLOSSARY. 
 
 Acetic acid, 67, 
 
 Acetate of potass, 75. 
 
 Achyla, 136. Microscopic plants, either Algae or fungi, 
 found parasitically on the bodies of dead flies in water, also 
 on fish, etc. 
 
 Achorion Schcenleinii, 329. A microscopic vegetation oc- 
 curring infavus (a skin disease). 
 
 Achromatic (Gr. a, and chroma, color). Without chromatic 
 aberration. 
 
 Achromatic object-glasses, 25. 
 u condenser, 33. 
 
 Acinetse, 162 (Gr. akinete, fixed). Infusorial animals, for- 
 merly supposed to be intermediate stages in the development 
 of Torticellse. 
 
 Accessories, microscopic, 32. 
 
 Actinia, 165 (Gr. aktin, a sun ray). Sea anemones, or Ac- 
 tinoid polyps. Formerly called animal flowers. 
 
 Acids, tests for, 109. 
 
 Adenoma, 272, 287 (Gr. aden, a gland). A glandular tu- 
 mor. 
 
 Adenoid Tissue, 194. Glandular tissue. 
 
 Adulteration of food, 323. 
 
 Adjustment, 51. 
 
 JEcidium, 363 (Gr. wheel-like). Minute parasitic fungi 
 (Order, Coniomycetes or Uredoideae], like little cups with red- 
 dish or brownish spores when mature. Earlier they are mi- 
 nute spots on the plants they infest. Known as " blight," 
 " brand," etc. 
 
 ^Etiology, 321 (Gr. treatise on causes'). The doctrine of 
 the causes of disease. 
 
 JEroscope, 321. 
 
 Agriculture, microscope in, 18. 
 
 Air-pump, 79. 
 
 Albuminous infiltration, 244. 
 " compounds, 184. 
 
 Albuminuria, 303. 
 
 Alcohol, 68, 108, 252. 
 
 " and acetic acid, 68. 
 " and soda, 68. 
 
INDEX AND GLOSSARY. 403 
 
 Alkalies, tests for, 108. 
 
 A Ikaloids, tests for, 18, 111. 
 
 Allanlois, 204 (Gr. sausage-like). An oblong sac developed 
 in the embiyonic life of animals near the end of the intestine, 
 and serving for temporary respiration. 
 
 Alcyonium, 165. A genus of Coralline polyps. 
 
 Algae, 139 (Lat. sea weeds}. The great variety in form and 
 organization shown by this class of plants render it an inter- 
 esting field of microscopic research. The families of Desmids 
 and Diatoms have been particular favorites. 
 
 Alternation of Generations, 126. This term denotes a form 
 of reproduction in which the young do not resemble the parent 
 of the animal but the grandparent. 
 
 Alimentary canal in insects, 177. 
 
 Amides, 184. A term used in chemistry to express a com- 
 pound ammonia, in which one, two, or three of the hydrogen 
 atoms are replaced by an acid radical. 
 
 Ammonia. Volatile alkali. Used in preparing carmine 
 fluids, 69, 72. Test for ammonia, 107. Used as a test, 108, 
 111. 112. The crystals of ammoniacal salts are often beautiful 
 microscopic objects. The hydrochlorate forms cubes, octahe- 
 dra, and trapezohedra, but if crystallized rapidly makes pecu- 
 liar featheiy crystals. It does not polarize. Crystals of oxa- 
 late. oxalurate, and purpurate of ammonia are beautiful objects 
 for the polariscope. 
 
 Ambulacra (Lat. ambulacrum, a place for walking). Holes 
 or avenues in the shell through which the tube feet of Echino- 
 derms are protruded. 
 
 Amnion, 204 (Gr. amnos, a lamb). One of the fetal mem- 
 branes of the higher vertebrates. 
 
 Amo3ba, 121 (Gr. amoibos, changing). Animals of simplest 
 form, composed of a glutinous living substance or bioplasm. 
 
 Amoeboid Cells, 121, 128. Cells with movements similar to 
 Amoeba have been found in vegetables as well as animals. See 
 Bioplasm. 
 
 Amplifier, 26, 346. 
 
 Amphipleura Pellucida, 56. A test diatom for high powers. 
 The valves are linear lanceolate, with a median longitudinal 
 line. No median nodule. The striae are exceedingly fine. 
 
404 INDEX AND GLOSSARY. 
 
 Amyhim, 132 (Gr. amuloa, starch). Starch. 
 
 Amyloid. A vegetable substance analogous to starch, but 
 turning yellow in water after having been colored blue by 
 iodine. 
 
 Amyloid Cell and Infiltration, 239. A waxy or lardaceous 
 albuminate infiltrated among the tissues. 
 
 Analogy. Resemblance in form but not in function, or in 
 function but not in form. 
 
 Analysis of urine, 300. 
 
 Analytic Crystals, 90, 113. Crystals which analyze polarized 
 light, as tourmaline, nitrate of potass, boracic acid, uric acid, 
 iododisulphate of quinia. 
 
 Anatomy of insects, 177. 
 
 Angioma, 269 (Gr. angion, a vessel). Blood tumor. 
 
 Anguillula, 171 (Lat. anguis, a snake). A genus of minute 
 animals, formerly classed among Infusoria, but now regarded 
 as nematoid Eutozoa. The " eels " in sour paste and vinegar 
 belong here. 
 
 Angular Aperture, 25. The angle measured by the arc of 
 a circle, the centre of which is formed by the focal point of the 
 objective, the radii being formed by the most extreme lateral 
 rays which the object-glass admits. 
 
 Anilin Staining- fluids, 69. Anilin Carmine, 69. Anilin 
 colors are of great interest in chemistry and microscopy. 
 Anilin is a base, forming salts with various acids, as hydro- 
 chlorate, nitrate, and oxalate of anilin. The substitution deri- 
 vatives of anilin are very complex and their colors various. 
 Mauvine forms a purple solution ; rosanilin, known also as 
 fuchsin, magenta, etc., a deep red; Hoffman's violet a rich 
 violet; anilin blues are numerous. There are also several ani- 
 lin greens, and chrysanilin dyes a golden yellow. 
 
 Animal parasites, 330. 
 
 Animalcule, 160. (A little animal.) Usually applied to In- 
 fusoria, Rotatoria, etc., but formerly given also to many of the 
 lower Algae. 
 
 Animalcule cage, 41. 
 
 Animal histology, 182. 
 
 Annelidse, 337. A gallicized form of Annulata. 
 
 Annulata, 172. Ringed worms. 
 
INDEX AND GLOSSARY. 405 
 
 Annual Rings, 156. Concentric rings seen in sections of 
 Dicotyledonous stems. They probably indicate periods of foli- 
 age, and more than one may be produced in a year. 
 
 Androspore, 152 (Gr. a male seed). A peculiar body set 
 free from a germ-cell during the development of (Edogonium, 
 and probably some other Confervaceae. 
 
 Annulus of Ferns, 155. The ring surrounding the capsule 
 which contains the spores. 
 
 Anomalous. Irregular, contrary to rule. 
 
 Antennse, 175 (Lat. antenna, a yard-arm). The jointed horns 
 or feelers of most Articulata. 
 
 Anther, 157 (Gr. anthos, a flower). The case which contains 
 the pollen of a plant. 
 
 Antheridia, 154. The so-called male organs of urn mosses 
 and similar plants. 
 
 Anther ozoids, 152. The fertilizing cells of some of the Con- 
 fervaceae. Used also synonymously \yith Spermatozoids. 
 
 Aphides, 126. Plant lice. Order, Herniptera. Their pro- 
 duction is an example of the alternation of generation as well 
 as parthenogenesis, 
 
 Aphtha, 329 (Gr. to fasten upon). Thrush, or muguet, a 
 disease of the mouth, etc., in children, or in adults towards the 
 fatal termination of chronic disease. Supposed to be the pro- 
 duct of Oidium albicans, or thrush fungus. 
 
 Aplanatic, 26 (Gr. without deviation). Refers generally .to 
 spherical aberration in lenses. 
 
 Apothecia, 154. The shields of Lichens ; firm horny disks 
 arising from the thallus, etc., containing spores. 
 
 Aqueous humor, 220. 
 
 Arachnida, 338 (Gr. arachne, the spider). The class of 
 animals containing spiders, scorpions, mites, etc. 
 
 Arachnoid Membrane, 225. A delicate cobweb-like mem- 
 brane between the pia mater and dura mater of the brain. 
 
 Arachnoidiscus, 148. A beautiful circular Diatom. The 
 markings vary. A. Ehrenbergii is common on the Pacific 
 coast. 
 
 Arcella, 159 (Lat. area, a chest). A genus of Rhizopods. 
 The test of the common species, A. vulgaris, has delicate 
 markings like the valves of Diatoms. 
 
406 INDEX AND GLOSSARY. 
 
 Archeus, 116. In the theory of Tan Helmont, the specific 
 agent presiding over vital functions. 
 
 Archegonium, 155 (Gr. arche, beginning; gone, seed). The 
 early condition of the spore-case in mosses, ferns, etc. Also 
 called Pistillidium. 
 
 Arteries, 201. Tubes conveying blood from the heart to the 
 capillaries. They have three coats, an outer, middle, and in- 
 ner coat. The inner is epithelial, the middle of unstriped 
 muscle, and the outer of fibrous connective tissue. They are 
 all supplied with nutrient bloodvessels, the vasa vasorum, and 
 have nerves from the ganglionic and spinal systems. 
 
 Arsenic, Tests for, 110. Arsenious acid. The most com- 
 mon form of crystal is octohedral or tetrahedral, but a right 
 rhombic form may be obtained by sublimation. Protoxide of 
 antimony will also yield by sublimation similar crystals, re- 
 quiring discrimination in cases of poisoning. 
 
 Arthritic deposits, 241 (Gr. arthron, a joint). 
 
 Areolar fibroma, 268. 
 
 Ascaris, 336 (Gr. askeris, a round worm). 
 
 Asci, 154 (Gr. askos, a bottle). A long or roundish spore- 
 case of fungi, containing spores. Called also thecse. 
 
 Ascomycetes, 138. An order of fungi characterized by 
 asci. 
 
 Asellus, 172. A. vulgaris, or water woodlouse, an Isopod 
 crustacean, is interesting to the microscopist since its trans- 
 parency permits a view of the circulation. 
 
 Aspergillus, 136, 325. A genus of Mucedines, forming 
 moulds, as the blue mould on cheese, etc. 
 
 Asterias, 168 (Gr. aster, a star). Star-fish. 
 
 Atheroma, 234 (Gr. porridge of meal). A disease of the ar- 
 teries characterized by a pulpy deposit. 
 
 Atrophy of heart, 242 (Gr. a trophe, not nourishing). 
 
 Avanturine. A mineral sometimes seen in cabinets consist- 
 ing of silex and scales of mica. Artificial avanturine is of 
 glass with crystals of metallic copper scattered through it. 
 
 Avicularia, 169 (Lat. avicula, a little bird). The bird's- 
 head processes of the Polyzoa. 
 
 Bacillaria, 144 (Lat. bacillum, a little staff). A genus of 
 Diatomacese. 
 
INDEX AND GLOSSARY. 407 
 
 Bacillus, 297, 327. A genus of Schizomycetous Fungi. 
 
 Bacterium, 135, 161, 315, 327 (Gr. bacterion, a staff). 
 A genus of Schizon^cetous Fungi. These rodlike, moving 
 filaments have been referred to the Algae as well as to the 
 animal kingdom. Their nature is very obscure. See p. 135. 
 
 Balsam (Canada), Liquid resin of Pinus balsamea, 73. 
 
 Balsam cement, 76. 
 
 Balsam mounting, 79. 
 
 Balanus, 174 (Gr. balanos, an acorn). The acorn-shell, a 
 family of Cirrhipeda. 
 
 Bathybius, 96, 158. Gelatinous matter from the bed of the 
 Atlantic Ocean, supposed by Huxley to be of the family of 
 Rhizopods. Its animal nature is disputed. 
 
 Beale's generalization in biology, 118. 
 
 Beale on Inflammation, 248. 
 
 Beale's carmine fluid, 69. 
 " injecting fluids, 72. 
 " tint-glass camera, 40. 
 
 Beck's microscope, 32. 
 
 " economic microscope, etc., 345. 
 " iris diaphragm, 33. 
 " illuminator, 38. 
 
 Bedbug, 339. Cimex Lectularius. 
 
 BelVs cement, 76. 
 
 Beroe, 167. Formerly classed among the cilograde Acalephs, 
 now generally in the class (Ctenophora) of the sub-kingdom 
 Coelenterata. 
 
 Bergmehl, 94. Mountain flour. A powdery mineral, con- 
 sisting largely of the silicious valves of Diatoms. In times of 
 scarcity in some countries it is mixed with food. 
 
 Bile in urine, 303. 
 
 Binocular Microscope, 30 (Lat. binus, two ; oculus, eye). 
 " Eye-piece, 30. 
 
 Bichromate of Potash, 68. 
 
 Bipinnaria, 168. The larval form of the star-fish, named 
 from the symmetry of its swimming organs. The star-fish is 
 developed around the stomach of the larva. 
 
 Biology, The Microscope in, 18, 116 (Gr. bios, life, and logos, 
 discourse). 
 
408 INDEX AND GLOSSARY. 
 
 Bioplasm living matter, 118, 122, 183. 
 " as germs of disease, 339. 
 
 Bismuth test, 306. 
 
 Blastema, 124 (Gr. blastos, a bud). A term given by the 
 early histologists to the fluid from which it was supposed cells 
 sprouted spontaneously. 
 
 Blastoderm, 201. The membrane of the ovum from which 
 all the tissues sprout or originate. 
 
 Blight, 136. A term loosely applied to a variety of diseases 
 in plants, as well as to the causes of such diseases, as insects 
 (animal blights) and parasitic fungi. 
 
 Bladder, 212. 
 
 Blood, 186. 
 
 Bloodvessels, 208. 
 
 Blood in disease, 295. 
 
 Blood-tests, 102, 105, 299. 
 
 Bone, 97, 195. 
 
 Boracic acid, 68, 
 
 Borax and carmine fluid, 69. 
 
 Botrytis, 18, 136. 
 
 Bowman's glands, 219. 
 
 Brain softening, 235. 
 
 Branchia (Gr. bragchia, the gill of a fish). A respiratory 
 organ adapted to breathe air dissolved in water. 
 
 Brunswick black, 76. 
 
 Bread, 323. Adulteration of flour is readily determined, 
 but the baking of bread affects the form of the starch-grains. 
 Various parasitic fungi and their spores may sometimes be 
 found on bread, 
 
 Brunonian movement, 53, 120. Molecular motion of parti- 
 cles suspended in fluid. 
 
 Bryozoa, 168 (Gr. bruon, moss j zoon, animal). 
 
 Buds, sections of, 157. 
 
 Bullseye condenser, 36. 
 
 Bunt, 136. 
 
 Cabinet, 81. 
 
 Calcium, chloride of, 75. 
 
 Calyptra, 154. The hood of an urn-moss. 
 
INDEX AND GLOSSARY. 409 
 
 Cambium. The viscid fluid between the bark and wood of 
 Exogens, when new wood is forming. 
 
 Camera lucida, 39. Used in microscopy for drawing the 
 optical image produced by it. 
 
 Calcification, 234, 241. Infiltration of animal tissues with 
 salts of lime. 
 
 Camphor, 133. 
 
 Canada balsam, 73. 
 
 Cancer, 288 (Lat. cancer, a crab). A malignant new for- 
 mation. 
 
 Canaliculi of bone, 196. 
 
 Capillaries, 201. Minute vessels between the terminal ar- 
 teries and veins. 
 
 Carbolic acid, 74. 
 
 Carbo-hydrates, 184. 
 
 Carmine fluids, 69. Carmine is a pigment made from cochi- 
 neal. 
 
 Cartilage, 195. 
 
 Catarrh, 254 (Gr. kata, down, and rheo, to flow). 
 
 Caseation, 233, 253. Transformation of a fatty into a cheesy 
 substance. 
 
 Carbuncle, 298. 
 
 Carbonate of lime, 99, 314. 
 
 Co.ustic potash, 67. 
 
 Cauliflower excrescence, 295. 
 
 Cavernous tumor, 270. 
 
 Cavities in crystals, 89. 
 
 Cells, 77 (Lat. cellar, a little chamber). 
 
 Cell, 117, 118. The elementary unit of organic structure. 
 " structure, 119. 
 " genesis, 124. 
 " wall, in plants, 129. 
 
 Cellulose, 67, 129. The proximate principle of cell-mem- 
 brane in plants, and of the mantle of Tunicata. 
 
 Cellular plants, 134. 
 
 Cements, 75. 
 
 Cercomonas, 331 (Gr. kerkos, the tail; monas, unity. A 
 tailed infusorial monad. 
 
410 INDEX AND GLOSSARY. 
 
 Cerebellum, 216. 
 
 Cerebral nerves, 216. 
 
 Cestum veneris, 167. 
 
 Cephalopoda, 171 (Gr. kephale, head ; poda, feet). 
 
 Characese, 154. 
 
 Chalk strata, 95. 
 
 Chemical reagents, 67. 
 
 " teste, 106. 
 
 " products of decay, 231. 
 Chloride of sodium, 68. 
 
 " " gold, 70. 
 
 Chlorophyll, 133 (Gr. chloros, green ; phyllos, leaf). The 
 green coloring-matter of plants. 
 
 Cholesterin, 233 (Gr. c/io/e, bile, and sfear, suet). 
 Chlorides in urine, 302, 314. 
 Chromic acid, 66, 67. 
 Chloride of calcium, 75. 
 Chorion, 204 (Gr. chorion, skin). 
 0%fe, 190 (Gr. chulos, juice). 
 Cicatricial tissue, 262. 
 
 Ot'fa'a, 124, 191 (Lat. cilium, an eyelash). Minute, hairlike 
 bodies, on cells. 
 
 Ciliograda, 167 (Lat. cilium, and gradior, I walk). 
 
 Ciliated epithelium, 191. 
 
 Cirrigrada, 167 (Lat. cirrus, a curl or tendril). 
 
 Cirrhipeds, 174 (Lat. cirrus, and pes, a foot). 
 
 Cirrhosis of Liver (252). Shrinking of the liver. 
 
 Circulation, 187. 
 
 Classes of microscopes, 28. 
 
 Ciliary motion, 161, 170. 
 
 Cleaning covers, 77. 
 
 Cleavage of yelk, 201. 
 
 Cloudy swelling, 244. 
 
 (7oaZ, 92. 
 
 Coccoliths, 96 (Gr. kokkos, a berry ; fa7ftos, a stone). 
 
 Cochlea, 222 (Gr. kochlos, a spiral shell). 
 
 Coddington lens, 23, 82. 
 
 Colors of flowers, 133. 
 
 Coloring matter, 184. 
 
INDEX AND GLOSSARY. 411 
 
 Collomia seeds, 130. 
 
 Colloid degeneration, 236 (Gr. holla, glue). 
 " tumors, 238. 
 " " of ovary, 239. 
 
 " cancer, 293. 
 Compressorium, 41. 
 Collins* s Harley microscope, 32. 
 
 " graduating diaphragm, 32. 
 Compound microscope, 23. 
 
 " crystals, 89. 
 
 " tissues, 197. 
 
 " eyes, 176. 
 
 Condensers, Achromatic, 33. 
 
 " JPe&s/er's, 34. 
 
 " Readers, 34. 
 
 Condensing lens, 37. 
 Conifer se, 131. 
 
 Conidia, 137. Reproductive granules of fungi and lichens. 
 Conjugation of cells, 140. 
 
 " in infusoria, 162. 
 
 Connective tissues, 67, 192. 
 
 Conchifera, 170 (Gr. concha, a shell ; /e-ro, I carry). 
 Contagium vivum, 339. 
 Condensing prism, 35, 347. 
 Correlation of force, 117. 
 Cornea, 220 (Lat. cornu, a horn). 
 Cora/, 164. 
 Corpus luteum, 215. 
 Cossus ligniperda, 179. 
 Core's or</an, 223. 
 Cor/is, 192, 286. 
 
 Crinoids, 167 (Gr. krinos, a lily ; eidos, form). 
 Croupous exudation, 257. 
 
 " pneumonia, 259. 
 Cuttle-fish bone, 170. 
 Crystalline forms, 86, 114. 
 Crystallization, 100. 
 Crystallography, 89. 
 Crystalloid, 66. Capable of crystallization. 
 
412 INDEX AND GLOSSARY. 
 
 Cryptogamia, 152 (Gr. kryptos, hidden, and gamos, marriage). 
 Plants with inconspicuous sexual organs. 
 
 Crustacea, 172. 
 
 Cyclops, 173. 
 
 Cypris, 173. 
 
 Cystin, 314. 
 
 Cryptococcus, 325. 
 
 Cyclosis, 129. Fluid circulation in plant-cells. 
 
 Dammar mounting, 74, 79. 
 
 Darkens selenite stage, 44. 
 
 Dark-ground illumination, 35. 
 
 Daphnia, 173. A genus of microscopic Crustaceans. The 
 water flea. 
 
 Deane's compound, 74. 
 
 Dead cells, 229. 
 
 " cell-membrane, 230. 
 
 Decapoda, 174 (Gr. deka, ten; poda, feet). 
 
 Decaying protoplasm, 229. 
 " nerve, 230. 
 " fat cells, 231. 
 " connective tissue, 231. 
 " - elastic fibre, 231. 
 " cartilage, 231. 
 " 6owe, 231. 
 
 Decomposing blood, 229. 
 
 Degeneration of tissues, 232. 
 
 Demodex folliculorum, 179. 
 
 Definition, 54. Power to give a distinct image. 
 
 Dental tissue, 192. 
 
 Dentine, 196. 
 
 Development of tissues, 201. 
 
 Dentzia scabra, 132. 
 
 Development of fungi, 137. 
 
 Desmidiaceae, 140. A family of Confervoid Algse. Micro- 
 scopic fresh-water organisms, generally green; epidermis not 
 silicious, as is the case with Diatoms. Reproduce by cell- 
 division, b} r zoospores, and by conjugation. The latter form 
 produces a sporangium, which is sometimes spiny, and has 
 been described as a species of Xanthidium. 
 
INDEX AND GLOSSARY. 413 
 
 Family 1. Closteriese. Ceils single, elongated, never spi- 
 nous, frequently not constricted in the middle; sporangia 
 smooth. 
 
 Gen. Closterium. Penium. Tetmemorus. Docidium. 
 Spirotsenia. 
 
 Family 2. Cosmariese. Cells single, constricted in the mid- 
 dle ; sporangia spinous or tuberculated. 
 
 Gen. Micrasterias. Euastrum. Cosmariurn. Xanthidium. 
 Arthrodesmus. Staurastrum. Didymocladon. 
 
 Family 3. Desmidese. Cells united into a filament , sporan- 
 gia spherical, smooth. 
 
 Gen. Hyalotheca. Didymoprium. Desmidium. Aptogo- 
 num. Sphoerozosma. 
 
 Family 4. Ankistrodesmise. Cells elongated, entire, small, 
 in fagot-like groups. 
 
 Gen. Ankistrodesmus. 
 
 Family 5. Pediastrese. Cells grouped in form of a disk or 
 star, or side by side in one or two short rows. 
 
 Gen. Pediastrum. Monactinus. Scenedesmus. 
 
 Diabetic sugar, 305. 
 
 Diagnosis, microscope in, 295. 
 
 Diaphragm, Rotary, 32. An instrument for intercepting 
 excessive ra} r s of light. 
 
 Diaphragm, cylinder, 32. 
 " graduating, 33. 
 
 " iris, 33. 
 
 Diatomacese, 56, 94, 141. A family of Algae. 
 
 Diffraction of Light, 54. Disturbance of the ray by the 
 edge of an opaque body. 
 
 Difflugia, 159. 
 
 Diphtheritic exudation, 260. 
 
 Discrimination of blood, 299. 
 
 Distomum, 335 (Gr. dis, double ; stomata,, mouths). 
 
 Disease germs, 339. 
 
 Dotted cells, 130. 
 44 ducts, 131. 
 
 Double Refraction^ 91. The power some crystals have of 
 exhibiting two images. 
 
 Double staining, 347. 
 
414 INDEX AND GLOSSARY. 
 
 Duchenne's trocar, 234. 
 
 Dytiscus, 177 (Gr. dytiskos, di\ 7 ing). 
 
 Ear, 222. 
 
 Earths, analysis of, 99. 
 
 Echinococcus, 171, 333 (Gr. echinos, a hedgehog; kokkus, 
 a berry). Larval forms (scolices) of tapeworms, known as 
 " hydatids." 
 
 Echinodermata, 167 (Gr. echinos, and derma, skin). Spiny- 
 skinned animals. 
 
 Ectosarc, 158 (Gr. ektos, outside; sarx, flesh). 
 
 Eczema, 256. A vesicular eruption on the skin. 
 
 Eggs of Insects, 175. These are interesting microscopic ob- 
 jects from the variety of their forms, colors, and markings, and 
 the singular lids of many of them. The markings are analo- 
 gous to other unicellular organisms, as spores, pollen grains, 
 Desmids, and Diatoms. 
 
 Elastic fibres, 194. 
 
 Elaters, 154 (Gr. elater, an impeller), In the Equisetaceas, 
 elaters are four elastic filaments attached to the spore, which, 
 by their uncoiling, jerk the spore away from its position. They 
 seem to be formed by spiral fissures in the outer coat of the 
 spore. In liverworts (Hepaticese) they are elastic fibres coiled 
 in membranous tubes, and originate as spiral fibres of vessels. 
 They are supposed to assist in the dispersion of spores. 
 
 Elytra, 175 (Gr. elution, a sheath). 
 
 Electrical cement, 76. 
 
 Elephantiasis, 270. A species of leprosj^ or skin disease. 
 
 Embryology, 204 (Gr. en, in ; bruo, I swell). 
 
 Embolism, 272. Result of occluding clots in bloodvessels. 
 
 Embryonic cells, 263. 
 
 Enchondroma, 278. Cartilaginous tumor. 
 
 Encephalon, development of, 203 (Gr. egcephalos, brain). 
 
 Encephaloid cancer, 292. 
 
 Endochrome, 152. Used for cell-contents of Algre. 
 
 Endogenous stems, 156 (Gr. endon, within ; ge/nnao, I bring 
 forth). 
 
 Endosmose, 129 (Gr. endon; otheo, I push). The current 
 flowing inwards when diffusion of fluids occurs through a 
 membrane. 
 
INDEX AND GLOSSARY. 415 
 
 Endothelium, 202 (Gr. endon; thallo, I bloom). 
 Entomostraca, 173. A family of Crustacea. 
 Entozoa, 171, 330 (Gr. entos, within, and zoon, an animal). 
 Epiderm, development of, 203. 
 
 Epithelium, 190 (Gr. epi, upon; thallo, I bloom). Cells 
 covering surfaces of animal bodies. 
 Epithelium in blood, 298. 
 " in urine, 309. 
 Epithelioma, 293. A species of cancer. 
 Epizoa, 330. Parasitic animals. 
 Eozoon, 84, 97 (Gr. eos, dawn ; zoon, animal). 
 Enamel, 192, 197. Covering of teeth. 
 Equisetaceae, 155. A family of Cryptogams. 
 Equisetum, 132. A genus of Equisetaceae. 
 Epiphytes, 324. Parasitic plants. 
 Epiblast, 202. Upper layer of blastoderm. 
 Errors of interpretation, 52. 
 Ether, 68, 108. 
 Eosin-staining, 348. 
 Eolis, 127. 
 
 Esophagus, 209 (Gr. oisophagus, the throat). 
 Examination of minerals, 85. 
 
 " of higher plants, 155. 
 
 " of sputum, 316. 
 
 " of the air, 321. 
 
 Excretions, 318. Products of waste or decomposition in- 
 capable of further use in the body. 
 Exudation, 247, 253. 
 
 corpuscles, 233. 
 
 Exogenous stems, 156 (Gr. exo, out, and gennao, to grow). 
 Dicotyledonous plants. 
 Eyes, care of, 49. 
 
 " of insects, 176. 
 Eye-pieces, 26. 
 Eye-piece micrometer, 38. 
 Eye-glass, 23. 
 Fatty tissue, 1 95. 
 " ac?8, 184. 
 " degeneration, 233. 
 
416 INDEX AND GLOSSARY. 
 
 Fatty infiltration, 243. 
 
 " " of liver, 244. 
 
 False membranes, 256. 
 
 Fermentation, 135. 
 
 " test for sugar, 306. 
 
 Feet of insects, 171. 
 
 Ferns, 155, 349. 
 
 Fehling's test for sugar, 305. 
 
 Fibres, 185. 
 
 Fibrillar connective, 194. 
 
 Fibrin, 253, 270 (Lat. fibra, a fibre). 
 
 Fibrinous exudation, 256. 
 
 Fibro-cartilage, 195. 
 
 Fibroma, 267. Connective tissue tumor. 
 " molluscum, 268. 
 
 Field-glass, 23. 
 
 Filaria in blood, 297, 337. 
 
 Fission of cells, 125. 
 
 Fixed oil in plants, 133. 
 
 Flannel, Natural. Interwoven filaments of Confervse, re- 
 sembling coarse cloth, sometimes found in summer on the 
 margins of ponds. 
 
 Flatness of field, 55. 
 
 Flea, 339. Pulex Irritans. The last segment of the abdo- 
 men of the female, called the pygidium, has disklike areolae, 
 which is sometimes used as a test-object. 
 
 Floscularia, 164. A genus of Rotator ia. 
 
 Flint, 96. 
 
 Fluid media, 66. 
 " mounting^ 80. 
 " cavities in minerals, 84, 89. 
 
 Flowers, 157. 
 
 Foraminifera, 95, 159. Small calcareous shells full of pores 
 or foramina. 
 
 Formed Material, 118. Structure produced by bioplasm. 
 
 Fossil plants, 93, 156. 
 
 Food, examination of, 323. 
 
 Freezing specimens, 228. 
 " microtome, 228. 
 
INDEX AND GLOSSARY. 417 
 
 Fraunhofer's Lines, 44, 101. Dark lines in the solar spec- 
 trum, seen by the spectroscope. 
 
 Frog-plate, 41. The common frog will afford means of 
 studying several kinds of structures. By scraping the roof of 
 the mouth with a scalpel, ciliated epithelium may be obtained 
 (page 191). The circulation of blood may be seen in the foot, 
 mesentery, lung, tongue, etc., by inclosing the frog in a wet 
 bag and extending the tissue over the aperture in the frog- 
 plate (page 187). The ova of the frog are frequently used in 
 the study of embryology, and the transparent parts of the 
 tadpole for observing the development of the tissues. 
 
 Fungi, 18, 127, 134, 138, 232, 324. 
 " in blood, 298. 
 " in urine, 311. 
 
 Galls. Abnormal growths on vegetables produced by the 
 sting or eggs of ffymenopterous insects. 
 
 Gammarus pulex, 174, 320 (Gr. gammarou, a lobster, and 
 Lat. pulex, a flea). 
 
 Ganglia, 200. Nervous knots. 
 
 Ganglionic Fibres, 199. Remak's fibres. 
 
 Gas-chamber, 42. 
 
 Gasteropoda, 170 (Gr. gaster, belly ; podes, feet). A class of 
 Mollusca. 
 
 Gelatinous injections, 71. 
 
 " connective tissue, 194. 
 
 Generative organs, 213. 
 
 Generations, alternation of, 126. 
 
 Germ-theory, 339. 
 
 " of Dr. Beale, 340. 
 
 Germ-cell, 125. Ovum. 
 
 Germinal Matter, 118, 122. Another name for bioplasm 
 living protoplasm or " cell-stuff." 
 
 Germinal vesicle, 201. 
 " spot, 201. 
 " plates, 202. 
 
 Germ-fungi, 325. Gymnomycetes. 
 
 GerlacWs carmine injection, 72. 
 
 Geology, microscope in, 92. 
 
 Giant- cells. 265. 
 
 27 
 
418 INDEX AND GLOSSARY. 
 
 Glass-covers, 77. 
 " slides, 77. 
 Glands of Brunner, 209. Intestinal glands. 
 
 " " Lieberkuhn, 209. Follicles of intestine. 
 Glandular Fibres, 131. Woody fibres of Coniferse. 
 
 " Tissue, 200. Gland structure. 
 
 " Epithelium, 191. Lining of glands. 
 Globules, 185. 
 
 Glomeruli of kidneys, 212. Arterial tufts of Malpighi, 
 Glioma, 277. Tumor of nerve connective tissue. 
 Globigerina, 96. A genus of Foraminifera. 
 Glycerin, 74, 228. The sweet principle of fats. 
 
 " and gelatin, 74. 
 
 " and gum, 74. 
 
 " mounting, 80, 228. 
 Goitre, 287. Tumor of thyroid gland. 
 Goadby's solution, 75. 
 Gold size, 75. 
 
 Goniometer, 86. An instrument for measuring angles of 
 crystals. 
 
 Gonozooid, 166. Sexual zooid of Hydroids. 
 
 Graduating diaphragm, 33. 
 
 Graafian Follicles, 215. Follicles of the ovary. 
 
 Granules, 185. 
 
 Granulation, 262. Mode of organization after suppuration. 
 
 " tissue, 262. 
 
 Grammataphora test, 57. 
 
 Gregarinse, 330 (Lat. gregarius, in flocks). A family of 
 parasitic Protozoans. 
 
 GundlacWs objectives, 346. 
 
 " condenser, 347. 
 
 Gum, 134. 
 
 Gustatory Cells, 218. Elements of organs of taste. 
 Guaiacum, test for blood, 300. 
 Hair, 191. 
 
 " of insects, 175. 
 (i worms, 172. 
 
 Hardening tissues, 62, 224, 227. 
 Hartnach's microscope, 32. 
 
INDEX AND GLOSSARY. 419 
 
 Haustellum, 177 (Lat. haustellum, a sucker). 
 
 Haematin, 103 (Gr. haima, blood). 
 
 Heart, 208. 
 
 " in insects, 178. 
 
 Haversian Canals, 196. Vascular canals in bone. 
 
 Hepaticde, 154. Liverworts (Gr. hepar, the liver). 
 
 Hepatic Lobules, 210. Elemental structures of the liver. 
 
 Herapathite, 113. lododisulphate of quinia. 
 
 Heterologous Formation, 263. A tumor differing from the 
 tissue it is found in. 
 
 HerscheVs doublet, 22. 
 
 High powers, 55. 
 
 Hipparchia Janira, 56. A species of Lepidoptera. 
 
 Histo-chemistry, 185. 
 
 Histology, 128, 182 (Gr. histos, tissue, and logos, discourse). 
 The science of tissues. 
 
 Histological preparations, 224. 
 
 Holothurise, 168 (Gr. Jiolos, the whole, and thura, a gate). 
 An order of Echinodermata. 
 
 Holland's triplet, 23. 
 
 Homologous Formation, 263. A tumor similar to the tissue 
 in which it is found. 
 
 House-fly, 339. 
 
 Huygenian eye-piece, 26 
 
 Hydroids, 165 (Gr. hydor, water, and ezWos, resemblance). 
 A class of Ccelenterata. 
 
 Hydrocyanic acid, test for, 107. 
 
 Hypersemia, 246 (Gr. hyper, excess ; haima, the blood). 
 
 Hypoblast, 202. The lower layer of the blastoderm. 
 
 Illumination, 22. 
 
 Illuminators, oblique, 34. 
 
 dark-ground, 35. 
 
 Indigo-carmine fluid, 70. 
 
 India-rubber, 133. 
 
 Imbedding tissues, 62, 227. 
 
 Immersion Lenses, 25, 51. Objectives requiring fluid between 
 them and the object. 
 
 Improvements in microscopes, 345. 
 
420 INDEX AND GLOSSARY. 
 
 Indifferent Fluids, 61, 66. Fluids which do not alter the 
 tissues. 
 
 Indifferent tissue, 264. 
 
 Infusoria, 160 (Lat. infusus, infused). 
 " families of, 163. 
 
 Infusorial earth, 94. 
 
 Inflammation, 246. 
 
 Inflammatory Corpuscles, 233. Fatty degeneration of epi- 
 thelium. 
 
 Injecting, 64, 70. 
 
 Insects, 174, 177. 
 
 Intestinal canal, 206. 
 " worms, 331. 
 " discharges, 318. 
 
 Interpretation, errors of, 52. 
 
 Inverted microscope, 106. 
 
 Invertebrata, classes of, 180. 
 
 Involuntary muscle, 197. 
 
 lod-serum, 66. Serum and iodine. 
 
 Iris-diaphragm, 33. 
 
 Ixodse, 338 (Gr. ixo, to adhere). 
 
 Kellner^s eye-piece, 26, 33. 
 
 Kidneys, 211, Urinary glands. 
 
 Labyrinthodon, 97 (Gr. labyrinth, a labyrinth, and odontes^ 
 teeth). 
 
 Labyrinth of Ear, 222. Essential part of organ, consisting 
 of vestibule, semicircular canals, and cochlea. 
 
 Lacunsb of Bone, 196. Cavities containing bioplasts. 
 
 Labium of Insects, 176. Underlip. 
 
 Lactification, 233. The last act of fatty degeneration. 
 
 Lardaceous Liver, 240. Amyloid infiltration. 
 
 Lacticiferous Vessels, 131. Containing milky juice, or latex^ 
 of plants. 
 
 Lamps for microscopists, 50. 
 
 Lawson's dissecting microscope, 60. 
 
 Lasso-cells, 165. Stinging cells of Polyps. 
 
 Leaves of plants, 157. 
 
 Leech, 172, 337. Hirudo medicinalis. 
 
 Leiomyoma, 266. Tumor of unstriped muscle. 
 
\ 
 INDEX AND GLOSSARY. 421 
 
 Lenses, 21. 
 
 Lerncea, 173. Parasitic Crustacea. 
 
 Leptothrix, 136, 260, 328. A fungus found on epithelium, 
 etc. 
 
 Lepidocyrtis, 56. An insect similar to Podura. 
 
 Lepra, 284. A peculiar skin disease. 
 
 Leucocytes, 189 (Gr. leukos, white, and kytos, a cell). White 
 cells. 
 
 Leucin, 232. A chemical product of decay. 
 
 Lepidoptera, scales of, 175. 
 
 Leukaemia, 296. Excessive number of white cells in 
 blood. 
 
 Lieberkuhn, 37. 
 
 Ligaments, 194. Fibrous tissues connecting bones. 
 
 Light for microscope, 50. 
 
 Life, theories of, 116. 
 
 Living Bodies, Element of, 117. Bioplasm or cell. 
 
 Litmus-paper, 107. 
 
 Ligneous Tissue, 130. Sclerogen. Woody fibre. 
 
 Lichens, 154. An order of Cryptogamous plants. 
 
 Liver, 210. Largest gland connected with nutrition. 
 
 Lignites, 93. Fossils of vegetable origin. 
 
 Liverworts, 154. Hepaticese. 
 
 Ligula, 176. Tongue of insects. 
 
 Lice, 339. 
 
 Lime water, 68. 
 " salts, 115. 
 
 Lipoma, 277. Fatty tumor. 
 
 Liver-fluke, 335. Distomum hepaticum. 
 
 Lister's antiseptic plan, 343. 
 
 Locomotive Organs, 215. Bone, muscle, etc. 
 
 Low powers, 55. 
 
 Logwood staining fluid, 70. 
 
 Lungs, 213. Organs of respiration. 
 
 Lutein Spectra, 105. Spectra from juice of corpora lutea in 
 the ovary. 
 
 Lupus, 283. A peculiar skin disease. 
 
 Lymphatics, 207. Vessels of the lymph. 
 
422 INDEX AND GLOSSARY. 
 
 Lymphatic glands, 207. 
 radicles, 207. 
 
 Lymph, 189 (Lat. a stream). 
 
 Lymphoid Organs, 208. Having structure like lymphatic 
 glands. 
 
 Lymphangioma, 270, Tumor of lymphatic vessels. 
 
 Lymphoma, 272. Adenoid tumor. 
 
 Magnesia salts, 115. 
 
 Maltwood's finder, 48. 
 
 Magnifying power, 22, 40. 
 
 Margarine, 232. 
 
 Marine glue, 76. 
 
 Malignancy, 263. 
 
 Malpighian tufts of kidney, 212. 
 " vessels of insects, 178. 
 
 Measuring objects, 38. 
 
 Medium powers, 55. 
 
 Metric System, 38. The French system of weights and 
 measures, based on the metre. The French unit of weight is 
 the gramme. 
 
 Metamorphosis, 126. Change of form. 
 
 Mechanism of microscope, 27. 
 
 Medusse, 167. Jelly-fish. 
 
 Melicertians, 164. A family of Rotifera. 
 
 Membrane, 185. 
 
 Medullary Sheaths of Nerves, 1 99. Sheath of axis. 
 
 " Eays, 156. Cellular plates from the pith to the 
 bark in exogenous stems. 
 
 Mesoblast, 202. The middle layer of the blastoderm. 
 
 Medulla Oblongata, 216. The upper part of spinal cord, 
 within the skull. 
 
 Metallic oxides, tests for, 110. 
 
 Microscope, compound, 23. 
 " testing the, 54. 
 
 Microspectroscope, 18, 44, 101. 
 
 Micromineralogy ', 84. 
 
 Microchemistry, 98. 
 
 Microchemical analysis, 106. 
 " apparatus, 98. 
 
INDEX AND GLOSSARY. 423 
 
 Microscopic accessories, 32. 
 " slides, 77. 
 
 " lamp, 37, 50. 
 
 " table, 50. 
 
 Micrometer, 38. 
 
 Microgonidia, 152. Bodies resulting from segmentation of 
 motile cells in cryptogams. 
 
 Microcytes, 297. Minute cells. 
 
 Microzymes, 135. Minute molecules found in some diseased 
 products. 
 
 Migration of cells, 1 89. 
 
 Milk, 315. 
 
 Mites, 178, 338. A family of Arachnida. 
 
 Micrococcus, 325. Minute vegetables, sometimes classed as 
 Algae. 
 
 Microsporon Audonini, 329. Fungus of Porrigo deeal- 
 vans. 
 
 Microsporon Furfur, 329. Fungus of Pityriasis. 
 
 Miliary tubercles, 274. 
 
 Moist-chamber, 41. 
 
 Holler's test-plate, 57. 
 
 Mounting objects, 76, 79. 
 
 Monera, 158. A term given to the simplest forms of animal 
 life. 
 
 Mouths of insects, 176. 
 
 Molecular movement, 120. 
 
 " Coalescence, 128. Action of chemical substances 
 on colloids in a nascent state. 
 
 Mosses, 154. 
 
 Moschus JavanicaSi 187. Musk deer. 
 
 Motions of objects, 53. 
 " of cells, 120. 
 
 Morbid anatomy, 226. 
 
 4< changes in inflammation, 246. 
 
 Morphological products, 1 83. 
 
 Mould diseases, 328. 
 
 Mucus, 190,309, 314. 
 
 Mucous membrane, 206. 
 " exudation, 254. 
 
424 INDEX AND GLOSSARY. 
 
 Mucoid degeneration, 235. 
 
 Mucous polypi, 287. 
 
 Mucin, 235. 
 
 Mucor, 13*6, 325. Mould-fungus. 
 
 Muriatic acid, 67. 
 
 Muller's eye fluid, 68, 227. 
 
 Muscardine, 18, 136. A fungous disease in silkworms. 
 
 Multipolar nerve-cells, 199. Cells with many fibres. 
 
 Muscle, 197. 
 
 " in insects, 179. 
 Muscular tissue growths, 266. 
 
 Mycelia of Fungi, 135, 137. Filaments of vegetative 
 cells. 
 
 Myelon, 203. Spinal cord. 
 Myxoma, 268. Gelatinous tumor. 
 Nachet's inverted microscope, 32. 
 
 " prism, 35. 
 
 Nais, 172. A genus of Choatopodous worms. 
 Nails, 192. 
 
 Naevus, 269. A vascular tumor. 
 Naphtha and creasote, 74. 
 Navicula rhomboides, 56. 
 Necrosis, 229. The death of tissue. 
 Necrosed muscle, 230. 
 
 Nematoid worms, 171 (Gr. nema, a thread, and eidos, form). 
 Nerve tissue, 198, 217. 
 
 " fibres, 199. 
 
 " cells, 199. 
 
 " preparations, 217. 
 Neurilemma, 199. Sheath of nerve-fibre, 
 Neuroma, 266. Tumor on nerve. 
 NichoPs prism, 43. 
 Nitrogenous substances, 67. 
 Nitric acid, 67. 
 Nitrate of silver fluid, 70, 108. 
 
 " injection, 73. 
 Nobert's lines, 56. 
 
 " illuminator, 35. 
 Nose-piece, 47. 
 
INDEX AND GLOSSARY. 425 
 
 Nostochinee, 151, 322. A family of Confervoid Algae. 
 
 Notochord, 203. The gelatinous column forming the pri- 
 mary state of spine in vertebrates, 
 
 Nucleus of Cells, 119. New centres of living matter. 
 
 Nutritive organs, 206. 
 
 Numbering blood-corpuscles, 296. 
 
 Oberhauser's drawing apparatus, 39. 
 
 'Object glasses, 25. 
 " finders, 48, 
 
 Oblique Illumination, 34. Light thrown obliquely through 
 an object. 
 
 Ocular micrometer, 38, 296. 
 
 Ocelli, 176. Facets of compound eyes of insects. 
 
 (Ecoid, 188. A constituent of the red blood-corpuscle. 
 
 Octospores, 153. Subdivisions of sporangia in certain 
 Algae. 
 
 Oidium Albicans, 329. Thrush-fungus. 
 
 Oil of cloves, 68, 80. 
 
 Oolites, 90. Kocks whose structure resembles eggs of fish. 
 
 Oospores, 152. Reproductive cells of Oscillatoria. 
 
 Operculum, 154. The lid of spore- capsules in mosses, etc. 
 
 Opaque injections, 65, 70. 
 " objects, 77. 
 
 Orbitalites, 159. Foraminiferous shells in limestone. 
 
 Organic principles, 183. Formative materials. 
 
 Organization after inflammation, 261. 
 
 Organ of Corti, 223. A complicate apparatus in the inner 
 ear. 
 
 Organs of special sense, 218. 
 
 Origin of rocks, 92. 
 
 Oscillatoriae, 151. A family of Confervoid Algae. 
 
 Osmic acid, 70. 
 
 Osseous tissue, 195. Bone. 
 
 Osteoblasts, 196. Cells developing bone. 
 
 Osteoma, 278. An osseous tumor. 
 
 Osteocho?idroma, 278. An ossifying enchondroma. 
 
 Ovum, 201. Egg. 
 
 Ovary, 214. Essential organ of reproduction in the female. 
 
 Ovipositors, 177. 
 
426 INDEX AND GLOSSARY. 
 
 Oxalic acid, 67. 
 
 Oxalate of. ammonia, 108. 
 " " lime, 313. 
 
 Pabulum, 118, 183. Nutritive material of cells. 
 
 Pacinian fluid, 75. 
 
 " corpuscles, 218. 
 
 Papilloma, 285. Papillary tumor. 
 
 Palaeontology, 97. Science of fossils. 
 
 Palmellacese, 139. A family of Confervoid Algae. 
 
 Palate of Molluscs, 171. Tube set with siliceous teeth. 
 
 Parasites, 324. (Gr. para, by the side of, and sitos, nour- 
 ishment). 
 
 Parapliyses, 154. Elongated cells in spore-cases of lichens- 
 
 Parasitic Crustacea, 173. 
 
 Parthenogenesis, 126. Reproduction without sexual union. 
 
 Pathological histology, 226. 
 " specimens, 227. 
 
 " new -formations, 262. 
 
 Parabolic illuminator, 36. 
 " speculum, 37. 
 
 Pancreas, 210. A salivary gland of the intestines. 
 
 Penetration, 55 Exhibition of structure below the focal 
 layer. 
 
 Periscopic eye-piece, 26. 
 
 Perforating glass, 78. 
 
 Penicillium, 136, 325. A species of mould-fungus. 
 
 Peristome, 154, Toothed fringe or spore-capsule of mosses. 
 
 Pernicious ansemia, 297. 
 
 Perivascular Canals, 207. Lymphatic sheaths of vessels. 
 
 Peyer's Glands, 209. Aggregations of glands in the walls of 
 intestines. 
 
 Pigmentation, 242. Infiltration of pigment. 
 
 Pigment bodies, 232. 
 " in lungs, 242. 
 " bacteria, 326. 
 
 Pistillidia, 154. Female organs of mosses, etc. 
 
 Phosphates, 313. 
 
 Photography, microscopic, 48. 
 
 Plant-sections, 153, 347. 
 
INDEX AND GLOSSARY. 427 
 
 Phanerogamia, 155 (Gr. phaneros, visible, and gamos, mar- 
 riage). 
 
 Physograda, 167. An order of Acalephs, now referred to 
 Hydroida. 
 
 Physalia, 167. Portuguese man-of-war. A genus of Hy- 
 droida. Sub-class, Siphonaphora. 
 
 Pleurosigma, 56. 
 
 Polariscope, 42, 99. 
 
 Polycysti.na, 95, 160. An order of Rhizopods. 
 
 Polymorphism, 136, 324. Various forms produced by the 
 same germ. 
 
 Polyps, 164 (Gr. polus, many ; pous, foot). 
 
 Polyzoa, 168 (Gr. polus, many ; zoa, animals). 
 
 Polypary, 166. The arborescent structure or Hydroids. 
 
 Polypite, 166. The nutritive zooid or compound. 
 
 Polygastrica, 160 (Gr. polus, many ; gaster, the stomach). 
 
 Pollen in air, 322. 
 
 Porifera, 160. Sponges. 
 
 Porpita, 167. A genus of Hydroida. 
 
 Pond-stick, 81. 
 
 Podura plumbea, 56, 175. A species of insects. 
 
 Family Podur elide. 
 
 Order Thysanura. 
 
 Polishing-slate, 94. Tripoli. 
 
 Potato disease, 136. A species of fungus. 
 
 Powers of objectives, 55. 
 
 Preparation of objects, 58, 61, 65, 84, 99, 156, 204, 277. 
 
 Preservative fluids, 73. 
 
 Preserving objects, 76. 
 
 Primordial Utricle, 129. The bioplasmic layer of the vege- 
 table cell-wall. 
 
 Protoplasm, 118, 128. " Physical basis of life," or the ele- 
 mentary cell material. 
 
 Progressive force, 130 . 
 
 Prothallium of Ferus, 126, 155. An intermediate form be- 
 tween the spore and the plant. 
 
 Protophytes, 129. Primitive plants. 
 
 Protozoa, 158. Simplest forms of animals. 
 
 Professional microscope, 345. 
 
428 INDEX AND GLOSSARY. 
 
 Primitive groove of ovum, 202. 
 Pier o-car mine fluid, 70. 
 Prussian blue fluid, 70. 
 Pneumonia, 259. Inflammation of lung. 
 Pus, 189, 248,314. 
 Pustules, 255. 
 
 Pyaemia, 272. Pus in blood. 
 
 Pulmonigrada, 166. An order of Acalephs, now generally 
 referred to Discophora (Hydroida). 
 
 Radiolaria, 158. An order of Rhizopods. 
 
 Raphides, 132. Crystals in vegetables. 
 
 Readers condenser, 34. 
 
 Red blood-corpuscles, 186. 
 
 Reproduction, 125. Multiplication of higher forms of life. 
 
 Resolution, 55. Exhibition of minute details. 
 
 " after inflammation, 261. 
 
 Resin, 133. 
 
 Reticulated Vessels, 131. Irregular deposit on walls of ducts. 
 Respiratory organs, 213. 
 Retina, 221. 
 
 Retrograde metamorphosis, 127. 
 Resting stage of cells, 140. See still-cells. 
 Receptacles of Algae, 153. The part which bears reproduc- 
 tive filaments. 
 
 Reticularia, 158. An order of Rhizopods. 
 Recurrent fibroid tumor, 279. 
 Refractive media, 53. 
 Rhodospermese, 153. Red sea-weeds. 
 Rhizopods, 158. Root-footed Protozoa. 
 Rotatoria, 163. Wheel animalcules. 
 Ringed worms, 337. Annelidse. 
 Rhabdomyoma, 266. Muscular tumors. 
 Rotifera, 160, 163. Wheel animalcules. 
 Round worms, 171, 336. 
 Rust, 136. A species of fungus. 
 Sarcode, 118. A synonym for protoplasm. 
 Salivary glands, 209. 
 
 " ' " of insects, 178. 
 
 " corpuscles, 189. 
 
INDEX AND GLOSSARY. 429 
 
 Sarcoma, 279. Fibro-plastic tumor. 
 
 Sarcina, 328. A vegetable organism sometimes classed 
 among Algse. 
 
 Sarcoptes Scabiei, 338. Itch-insect. 
 
 Sandhopper, 174. An amphipod Crustacean. 
 
 Sclerogen, 130. Woody tissue. 
 
 Scales of Lepidoptera, 175. 
 
 Section-cutter, 63. 
 
 Sections of hard tissues, 62. 
 
 Secretory Organs, 208. Glands. 
 
 Section of skin, 218. 
 
 " " crystals, 100. 
 
 " " embryo, 205. 
 
 " knife, 228. 
 
 Sebaceous Glands, 209. Glands of skin secreting fatty matter. 
 Sea nettles, 166. Jelly-fish. 
 " slugs, 167. Holothuria, etc. 
 " urchins, 169. Echinus, etc. 
 Serpula, 172. A genus of Annulata. 
 Setae, 177. Lancets of Diptera. 
 Sensory Organs, 218. Organs of special sense. 
 Selenite stage, 44. 
 Seeds, 157. 
 Serous infiltration, 245. 
 
 " exudation, 253. 
 Screw bacteria, 327. 
 
 Scolex of Tapeworm, 332. The head set free from the csyt 
 in development. 
 
 Scirrhus, 288. Hard cancer. 
 Schacht's staining fluid, 68. 
 Scalariform Vessels, 155. Vessels of ferns. 
 Showers of Flesh and Blood, 322. Gelatinous masses, of 
 vegetable origin. 
 
 Shadbolt's turntable, 78. 
 Shell structure, 170. 
 
 Steel Disk, 40. A substitute for the camera lucida. 
 Spectra, 102. Lines or bands seen with the spectroscope. 
 Soil and water, examination of, 322. 
 
 Somatopleure, 203. Layers of the embryo which form the 
 walls of chest and abdomen. 
 
430 INDEX AND GLOSSARY. 
 
 Softening of brain, 235. 
 
 Sort, 155. Fructifying spots of ferns. 
 Soda, 115. 
 
 Side reflector, 37. 
 
 Simple microscope, 21. 
 
 Smut, 136. A species of fungus. 
 
 Sperm-cell ', 125. A synonym for sperraatozoid. 
 
 Spectrum Analysis. 101. Analysis by means of the spectro- 
 scope. 
 
 Spiral Motion, 130. From progression of the centripetal 
 point in space. 
 
 Spiral Vessels, 131. A spiral deposit in ducts of plants. 
 
 Spot lens, 36. 
 
 Sphagnum, 155. Bog-moss. 
 
 Spherical Aberration, 22. Errors in lenses from spherical 
 shape of surface. 
 
 Sphceroplea, 152. A species of Cryptogamous plants. 
 
 Sponges, 160. Poriferous Rhizopods. Some form of them 
 a sub-class, Polystornata. 
 
 Spontaneous Generation, 125. The theory of life without 
 parentage. 
 
 Spring clips, 80. 
 
 Spiders, 179. Class Arachnida. 
 
 Spermatozoids, 201, 214, 311. The male elements of im- 
 pregnation. 
 
 Splanchnopleure, 203. An embryonic layer forming the wall 
 of the intestinal canal. 
 
 Sporangia, 154. Spore-cases of Cryptogams. 
 
 Spinal cord, 216. 
 " nerves, 216. 
 
 Splenic fever, 297. 
 
 Spirilla 297, 328. Screw bacteria. 
 
 Sputum, 316. Discharges from the mouth. 
 
 Specific gravity of urine, 301. 
 
 Stage micrometer, 38. 
 
 Staining cells, 122. 
 " tissues, 63. 
 " fluids, 69. 
 
 Starch, 132. 
 
 Stems of plants, 156. 
 
INDEX AND GLOSSARY. 431 
 
 Still-cells, 140. A condition of cells of the unicellular Algse, 
 distinguished from the motile state. 
 Student's microscopes, 28. 
 Strieker's gas-chamber, 41. 
 
 Star-fish, 167. Order Asteroidea. Class Echinodermata. 
 Stings, 177. 
 
 Stemrnata, 176. Solitary eyes of insects, etc. 
 Striped Muscle, 198. Voluntary fibres. 
 Stomata, 157. Openings in epiderm of leaves. 
 Squamous Epithelium, 191. Edges of cells overlapping. 
 Sublimation, 99. Dry evaporation and condensation. 
 Surirella Gemma, 56, 58. A test Diatom. 
 Suppuration, 262. One of the results of inflammation. 
 Sugar in urine, 305. 
 
 Sucker Worms, 334. Order Trematodes. Class Yermas. 
 Sweat glands, 209. 
 
 Sympathetic Nerve, 215. The nerve of the viscera and blood- 
 vessels. 
 
 Syphilitic blood, 298. 
 
 Syphiloma, 281. A tumor of syphilitic origin. 
 Synovial Fluid, 190. Secretion from the synovial membrane 
 of joints. 
 
 Table, 50. 
 
 Tardigrada, 164. Water-bears. 
 
 Tapeworm, 171, 381. 
 
 Tactile Papillae, 218. Organs of touch in the skin. 
 
 Tallow, 133. 
 
 Tests, microscopic, 54. 
 " micro-chemical, 106. 
 " fjor alkalies, 108. 
 " for acids, 109. 
 " for oxides, 110. 
 " for blood, 102. 
 
 Talitrus Saltator, 174. The sandhopper. 
 
 Teleology, 19. Exhibition of evidences of design in nature. 
 
 Teeth, 97, 196. 
 
 Tetraspores, 153. Quadruple spores of Algse. 
 
 Terebratula, 170. A genus of fossil shell. 
 
 Tessellated Epithelium, 190. The cells lying edge to edge. 
 
 Termination of nerves, 200. 
 
432 INDEX AND GLOSSARY. 
 
 Thin cells, 77. 
 
 Thread-worms, 336. 
 
 " capsules, 165. Netting or lasso-cells of polypi. 
 
 Thecx, 155. Capsules inclosing spores of ferns. 
 
 Theories of life, 116. 
 
 Thoracic Duct, 208. Reservoir of the lymph. 
 
 Thwaite's fluid, 74. 
 
 Thiersch's carmine fluid, 69. 
 " blue injection, 72. 
 " red 72. 
 
 Ticks, 179, 338. Family Ixodae. Order Acarinse. Class 
 Crustacea, 
 
 Tissue elements, 185. 
 
 Torula, 135, 325. The " yeast-plant " fungus. 
 
 Tow-net, 82. 
 
 Taenia, 171. The tapeworm, called also Cestodes. See p. 
 331. 
 
 Transformation, 126, 264. Variations in development. 
 
 Transparent injections, 72. 
 
 Triple phosphates, 232, 240, 313. 
 
 Tradescantia, 129. A genus of Commebynacese, known as 
 spider-worts. 
 
 Trichomonas, 320. A genus of Infusoria. 
 
 Tricophyton Tonsurans, 328. The parasitic fungus of syco- 
 sis, etc, 
 
 Trommer's Test, 305. A test for sugar in urine. 
 
 Trichina Spiralis, 171, 337. A species of Nematoid worm. 
 
 Tripoli, 94. Polishing slate containing Diatoms, etc. 
 
 Thrombosis, 270. Coagula of blood in the vessels. 
 
 Turntable, 78. 
 
 Tunicata, 169. A class of Mollusca. 
 
 Tube casts, 311. 
 
 Tubercle, 234, 274, 276. 
 
 Tubuli Seminiferi, 214. Tubules of the testes. 
 
 Turpentine, 68. 
 
 Tyrosin, 232, 314. A chemical product of decomposition. 
 
 Uric acid, 242, 312. 
 
 Uredo, 136. A genus of fungi, producing rust, etc. 
 
 Urinary deposits, 307. 
 " examination, 300. 
 
INDEX AND GLOSSARY. 433 
 
 Urates, 313. 
 
 Ureters, 212. 
 
 Urea, 301. 
 
 Uriniferous Tubes, 211. Glandular tubes of kidney. 
 
 Unstriped Muscle, 198. Involuntary fibres. 
 
 Unipolar Nerve-cell, 199. Cells with one fibre. 
 
 Umbilical Vesicle, 203. An appendage of the vertebrate 
 foetus. 
 
 Ulvacese, 151. A family of Confervoid Algae. 
 
 Varieties of bioplasm, 123. 
 
 Vascular tissue, 201. 
 
 Valentin's knife, 62. 
 
 Vacuoles, 162. Spaces or watery vesicles in the bodies of 
 Infusoria, etc. 
 
 Vaginal Discharges, 319. 
 
 Vernier, 43. A short graduated scale, sliding on a larger 
 scale, so as to show fractions of divisions. 
 
 Vegetable cells, 128, 134. 
 
 Velella, 167. A genus of animals now referred to the Hy- 
 drozoa. 
 
 Ventral Laminse of Embryo, 203. Parts of the blastoderm of 
 the ovum. 
 
 Vegetative Organs, 206. Pertaining to nutrition, etc. 
 
 Vesicles, 254. Products of inflammation of the skin. 
 
 Vtbriones, 135. See Vibrio. 
 
 Vinegar Eels, 171. A kind of Xematoid worms. 
 
 Vine Disease, 136. A species of fungus. 
 
 Vibrio, 327. A genus of filamentous Bacteria. 
 
 Vibracula, 169. Appendages of Polyzoa, from which vibra- 
 tile filaments project. 
 
 Vitellus, 201. The yolk of the ovum. 
 
 Vitelline Membrane, 201. The membrane surrounding the 
 yolk in the ovum. 
 
 Visual organs, 219. 
 
 Vitreous humor, 220. 
 
 Vorticella, 161. A genus of Infusoria. Bell-shaped animal- 
 cules. 
 
 Volatile oil, 133. 
 
 Volvox, 140. A genus of Confervoid Algoe. 
 
 28 
 
434 INDEX AND GLOSSARY. 
 
 Voluntary muscle, 197. 
 
 Vomited matters, 317. 
 
 Warm stage, 42. 
 
 Wandering-cells, 121, 247. Leucocytes which traverse the 
 tissues. 
 
 Water-bears, 164. The Tardigrada, placed by some in the 
 class Arachnida. 
 
 Water-fleas, 178. Several kinds of microscopic Entomos- 
 tracan Crustaceans. 
 
 Wax, 133. 
 
 Water woodlouse, 172. An Isopod Crustacean. 
 
 Warts, 192. 
 
 Wenham's prism, 30. 
 
 li reflex prism, 347. 
 
 Webster's condenser, 34. 
 
 White blood-cells, 188. 
 " varnish, 76. 
 
 Woolaston doublet, 23. 
 
 Working distance, 51. 
 
 Woodward's prism, 347. 
 
 Xanthidia, 96. Sporanges of Desmidiaceas found in flint. 
 
 Xanthoma, 277. 
 
 Yeast-cells, 136. The Torula or yeast fungus. 
 
 Yellow tubercle, 274. 
 " elastic fibre, 194. 
 
 Yolk, 201. Contents of the vitelline membrane of the 
 ovum. 
 
 Zentmayer's microscope, 30. 
 
 " Centennial microscope, 345. 
 
 " histological " 345. 
 
 Zooid, 188. One of the constituents of the red blood-disk. 
 
 Zoea, 174. The larval form of the crab. 
 
 Zoospores, 140. Ciliated cells of Algae, etc., produced by 
 segmentation, and producing new individuals after being en- 
 cysted. 
 
 Zoology, microscope in, 158. 
 
 Zoophytes, 164. Animal flowers. A name formerly given 
 to Actinea and other Hydroids. 
 
 Zygnema, 151. A genus of Confervoid Algae. 
 
BAUSCH & LOME OPTICAL CO., 
 
 MANUFACTURERS OF 
 
 The Leading American Microscopes, 
 
 OBJECTIVES ACCESSORIES. 
 
 INVESTIGATOR MICROSCOPE. 
 
 ROCHESTER, N. Y.; 179 & 181 North St. Paul Street. 
 NEW YORK; 37 Maiden Lane. 
 
 CATALOGUE C,N APPLICATION. 
 
R. & J. BECK, 
 
 MANUFACTURING OPTICIANS, 
 
 Philadelphia, Penna., 
 
 Beg to call the attention of 
 microscopists to the following 
 NEW apparatus. 
 
 The Scholar's Microscope. 
 Complete, .... $25.00 
 
 The Lithological Micro- 
 scope. 
 
 Complete in case . . Sno.oo 
 
 The "Ideal" Microscope. 
 
 Monocular, complete, $ 85.00 
 Binocular, " 110.00 
 
 The Improved National 
 Microscope. 
 
 Monocular, complete, $120.00 
 Binocular, " 150.00 
 
 Photographic Attachment 
 
 Microscope. 
 Price, $18.00 
 
 BECK'S NATIONAL MICROSCOPE. 
 
 Together with every description of apparatus for the preparation and 
 examination of objects in every department of Natural History. Glass 
 Slips and Covers, Cements, Preservation Media, Dissecting Instruments, 
 Microtomes, Turntables, etc., all of the very best description and at moderate 
 prices. EVERY ARTICLE GUARANTEED. 
 
 Illustrated condensed Price-List of 32 pages mailed FREE, to any address 
 in the world. Full Catalogue of 176 pages, on receipt of 15 cts. in stamps. 
 
 R. & J. BECK, 
 
 No. 1O16 Chestnut St., 
 
 PHILADELPHIA, PENNA. 
 
JANUARY, 1888. 
 
 CATALOGUE 
 
 ~^T~ CATALOGUE 
 
 OF 
 
 MEDICAL, DENTAL, 
 
 Pharmaceutical & Scientific Publications, 
 
 % 
 
 WITH A CLASSIFIED INDEX, 
 
 PUBLISHED BY 
 
 P. BLAKISTON, SON & CO., 
 
 (SUCCESSORS TO LINDSAY & BLAKISTON) 
 
 Booksellers, Publishers and Importers of Medical and Scientific Books, 
 No. 1012 WALNUT STREET, PHILADELPHIA. 
 
 THE FOLLOWING CATALOGUES WILL BE SENT FREE TO ANY ADDRESS, 
 UPON APPLICATION. 
 
 This Catalogue, including all of our own publications. 
 
 A Catalogue of Books for Dental Students and Practitioners. 
 
 A Catalogue of Books on Chemistry, Pharmacy, The Microscope, Hygiene, Human Health, 
 Sanitary Science, Technological Works, etc. 
 
 Students' Catalogue, including the "Quiz-Compends" and somy of the most prominent Text- 
 books and manuals for medical students. 
 
 A Complete Classified Catalogue (68 pages) of all Books on Medicine, Dentistry, Pharmacy 
 and Collateral Branches. English and American. 
 
 A Catalogue of Medical and Scientific Periodicals and Physicians' Visiting Lists, giving club rates. 
 P. Blakiston, Son & Co.'s publications may be had through Booksellers in all the principal 
 
 cities of the United States and Canada, or any book will be sent, postpaid, by the publishers, 
 
 upon receipt of price, or will be forwarded by express, C. O. D., upon receiving a remittance of 
 
 25 per cent, of the amount ordered, to cover express charges. Money should be remitted by 
 
 postal note, money order, registered letter, or bank draft. 
 
 $&&** All new books received as soon as published. Special facilities for importing book? 
 
 from England, Germany and France. 
 
 The Physician's Visiting List. See last fiage. 
 
CLASSIFIED LIST, WITH PRICES, 
 
 OF ALL BOOKS PUBLISHED BY 
 P. BLAKISTON, SON & CO., PHILADELPHIA. 
 
 or further information in reference to these Books, see following descriptive catalogue. When the 
 price is net given below, the book is out of print or about to be published. 
 Cloth binding, unless otherwise specified. 
 
 ANESTHETICS. 
 Buxton. Anaesthetics. - 
 Sansom. Chloroform. - 1.25 
 Turnbull. 2d Ed. - 1.50 
 Cocaine. - - .50 
 
 ANATOMY. 
 Heath. Practical. - - 5.00 
 Holden. Dissector. Oil-cloth, 4.50 
 Osteology. - - 6.00 
 Potter. Compend of. 4th 
 Ed. 117 Illustrations. - i.oo 
 Wilson. loth Ed. - 6.00 
 
 ATLASES AND DIAGRAMS. 
 Bentley and Trimens. 
 Medicinal Plants. - - 75.00 
 Braune. Of Anatomy. - 8.00 
 Flower. Of Nerves. - 3.50 
 Heath. Operative Surgery. 12.00 
 Marshall's Physiol. Plates. 80.00 
 Savage. Pelvic Organs. 12.00 
 Schultze. Obstetrical Plates. 25.00 
 
 BRAIN AND INSANITY. 
 Bucknill and Tuke. Psycho- 
 logical Medicine. - - 8.00 
 Gowers. Diagnosis of Dis- 
 eases of the Brain. New Ed. 2.00 
 Mann's Psychological Med. 5.00 
 Roberts, Surgery of. - 1.25 
 Wood. Brain and Overwork. .50 
 
 CHEMISTRY. 
 Allen. Commercial Organic 
 Analysis. 2d Ed. Volume I. 4.50 
 
 Fox and Gould. The Eye. i.oo 
 Horwitz. Surgery. 3d Ed. i.oo 
 Hughes. Practice. 2 Pts. Ea. i.oo 
 Landis. Obstetrics. 3d Ed. i.oo 
 Leffmann's Chemistry. i.oo 
 Mason. Electricity. - i.oo 
 Morris. Gynaecology. - i.oo 
 Potter's Anatomy, including* 
 Visceral Anatomy. 117 Illus. i.oo 
 Materia Medica. 4th Ed. i.oc 
 Roberts. Mat. Med. and Phar. 2.00 
 Stewart, Pharmacy. 2d Ed. i.oo 
 Ward's Chemistry. 2d Ed. i.oo 
 
 DEFORMITIES. 
 Churchill. Face and Foot. 3.50 
 Coles. Of Mouth. - 4.50 
 Prince. Orthopaedics. - 4.50 
 Reeves. - 2.25 
 Roberts. Club-foot. - .50 
 
 DENTISTRY. 
 Barrett. Dental Surg. - i.oo 
 Flagg. Plastics. - - 4.00 
 Gorgas. Dental Medicine. 3.25 
 Harris. Principles and Prac. 6.50 
 
 Heath. Dis. of Jaws. - 4.50 
 Leber and Rottenstein. 
 Caries. - - - - 1.25 
 Richardson. Mech. Dent. 4.50 
 Stocken. Materia Medica. 2.50 
 Taft. Operative Dentistry. 4.25 
 , Index of Dental Lit. 2.00 
 Talbot. Irregularities of the 
 Teeth, - - - 2.00 
 Tomes. Dental Surgery. 5.00 
 
 
 Bartley. Medical. 2.50 
 Bloxam's Text-Book. 3.75 
 Laboratory. 1.75 
 Bowman's Practical. 2.00 
 Leffmann's Compend. - i.oo 
 Muter. Pract. and Anal. 2.00 
 Richter's Inorganic. - 2.00 
 Organic. - - 3.00 
 Stammer. Problems. - .75 
 Sutton. Volumetric Anal. 5.00 
 Thompson's Physics. - 
 Tidy. Handbook of. - 5.50 
 Trimble. Analytical. - 1.50 
 Vacher's Primer of. - .50 
 Valentin. Qualt. Analy. 3.00 
 Ward's Compend. - - i.oo 
 Watts. (Fowne's) Inorg. 2.25 
 
 White. Mouth ancfTeeth. .50 
 DICTIONARIES. 
 Cleveland's Pocket Medical. .70 
 Cooper's Surgical. - - 12.00 
 Harris* Dental. - - 6.55 
 Longley's Pronouncing - i.oo 
 
 DIRECTORY. 
 Medical, of Philadelphia, 
 Pa., Del. and South N. J. 2.50 
 
 EAR. 
 Burnett. Hearing, etc. .50 
 Jones. Aural Surgery. - 2.75 
 Pritchard. Diseases of. 1.50 
 Randall & Morse. Atlas. 5.00 
 Woakes. Deafness, etc. 1.50 
 
 Wolff. Applied Medical Chem- 
 istry. .... j.jo 
 
 F.T.F.PTP TPTTV 
 
 CHILDREN. 
 
 Chavasse. Mental Culture of. i.oo 
 Day. Diseases ofr - - 3.00 
 Dillnberger. Women and. 1.50 
 Ellis. Mother's book on. .75 
 
 Goodhart and Starr. 3.00; Sh. 3.50 
 Hale. Care of. - . 75 
 
 Hillier. Diseases of. - 1.25 
 Meigs. Infant Feeding and 
 
 Milk Analysis. - - i.oo 
 Meigs and Pepper's Treatise.s.oo 
 Money. Treatment of. - 3.00 
 Smith. Wasting Diseases of. 3.00 
 Clinical Studies. - 2.50 
 Starr, Digestive Organs of. 2.50 
 
 COMPENDS 
 
 And The Quiz-Compends. 
 
 Brubaker's Physiol. 4th Ed. fi .00 
 
 Althaus. Medical Electricity. $6.00 
 Mason's Compend. - i.oo 
 
 Reynolds. Clinical Uses. i.oo 
 
 EYE. 
 
 Arlt. Diseases of. - - 2.50 
 Carter. Eyesight. - - 1.25 
 Daguenet. Ophthalmoscopy. 1.50 
 Fox and Gould. Compend. i.oo 
 Gowers. Ophthalmoscopy. 6.00 
 Harlan. Eyesight. - .50 
 
 Hartridge. Refraction. 2.00 
 
 Higgins. Manual. - 
 
 Handbook, - .50 
 
 Liebreich. Atlas of Ophth. 15.00 
 Macnamara. Diseases of. 4.00 
 Meyer and Fergus. Com- 
 plete Text-Book, with Colored 
 Plates. - - - - 4.50 
 
 Morton. Refraction. 3d Ed. i.oo 
 Ophthalmic Review. 
 
 Monthly. ... 3.00 
 
 FEVERS. 
 
 Collie, On Fevers. - - 2.50 
 
 Welch. Enteric Fever. 2.00 
 
 HEADACHES. 
 
 Day. Their Treatment, etc. 1.25 
 Wright. Causes and Cure. .50 
 
 HEALTH AND DOMESTIC 
 
 MEDICINE. 
 
 Bulkley. The Skin. - .50 
 
 Burnett. Hearing. - .50 
 
 Cohen. Throat and Voice. .50 
 Dulles. Emergencies. - .75 
 
 Harlan. Eyesight. - .50 
 
 Hartshorne. Our Homes. .50 
 
 Hufeland. Long Life. - i.oo 
 Lincoln. Hygiene. - .50 
 
 Osgood. Winter. - - .50 
 
 Packard. Sea Air, etc. .50 
 
 Richardson's Long Life. .50 
 
 Tanner. On Poisons. - .75 
 
 White. Mouth and Teeth. .50 
 Wilson. Summer. - .50 
 
 Wilson's Domestic Hygiene, i.co 
 Wood. Brain Work. - .50 
 
 HEALTH RESORTS. 
 
 Madden. Foreign. 2.50 
 Packard. Sea Air and Bath'g. .50 
 Solly. Colorado Springs. .25 
 
 HEART. 
 
 Balfour. Diseases of. - 5.00 
 
 Fothergill. Diseases of. 3.50 
 
 Sansom. Diseases of. - 1.25 
 
 HISTOLOGY. 
 (See Micoscope and Pathology. 
 
 HOSPITALS. 
 
 Burdett. Pay Hospitals. 2.25 
 Domville. Hospital Nursing. .75 
 
 HYGIENE. 
 
 Bible Hygiene. - - i.oo 
 Frankland. Water Analysis, i.oo 
 Fox. Water, Air, Food. 4.00 
 Lincoln. School Hygiene. .50 
 Parke's Hygiene. 7th Ed. 4.50 
 Wilson's Handbook of. - 2.75 
 Domestic. - - i.oo 
 
 KIDNEY DISEASES. 
 
 Beale. Renal and Urin. 1.75 
 Edwards. How to Live with 
 
 Bright's Disease. - - .50 
 
 Greenhow. Addison's Dis. 3.00 
 
 Ralfe. Dis. of Kidney, etc. 2.75 
 
 Tyson. Bright's Disease. 3.50 
 
 LIVER. 
 
 Habershon. Diseases of. 1.50 
 
 Harley. Diseases of. - 3.00 
 
 LUNGS AND CHEST. 
 
 See Phy. Diagnosis and Throat. 
 
 Williams. Consumption. 5.00 
 
 MARRIAGE. 
 
 Ryan. Philosophy of. - i.oo 
 
 MATERIA MEDICA. 
 
 Biddle. loth Ed. - - 4-00 
 
 Charteris. Manual of. - 
 
 Gorgas. Dental. 2d Ed. 3.00 
 
 Merrell's Digest. - 4-<x> 
 
 Phillips. Vegetable, Organic 
 
 and Animal. New Ed. 7.50 
 
 Potter's Compend of. 4th Ed. i.oo 
 
 Handbook of. - 3.00 
 
 Roberts' Compend of. - 2.00 
 
CLASSIFIED LIST OF P. BLAKISTON, SON 6- CO.'S PUBLICATIONS. 
 
 MEDICAL JURISPRUDENCE. 
 Abercrombie's Handbook, 2.50 
 Reese's Text-book of. 3.00; Sh. 3.50 
 Woodman and Tidy's Treat- 
 ise, including Toxicology. 7.50 
 
 MICROSCOPE. 
 Beale. How to Work with. 7.50 
 
 - In Medicine. - 7.50 
 Carpenter. The Microscope. 5.50 
 Lee. Vade Mecum of. - 3.00 
 MacDonald. Examination of 
 
 Water by. 2.75 
 
 Martin. 'Mounting. - $2.75 
 Wythe. The Microscopist. 3.00 
 
 MISCELLANEOUS. 
 Allen. The Soft Palate. 
 Beale. Life Theories, etc. 
 
 - Slight Ailments. 
 
 - Bioplasm. 
 
 .50 
 2.00 
 1.25 
 2.25 
 Life and Vital Action. 2.00 
 
 Black. Micro-Organisms. 
 Cobbold. Parasites, etc. 
 Edwards. Malaria. - 
 - Vaccination. - 
 Gross. Life of Hunter. 
 Haddon. Embryology. - 
 
 1.50 
 5.00 
 .50 
 .50 
 1.25 
 6.00 
 
 Hare. Tobacco. Paper, .50 
 
 Henry. Anaemia. - - .75 
 
 Hodge. Foeticide. - Paper, .30 
 Holden. The Sphygmograph. 2.00 
 Kane. Opium Habit. - 1.25 
 MacMunn. The Spectroscope 3.00 
 Murrell. Massage. 2d Ed. 1.25 
 Smythe. Med'l Heresies. 1.25 
 Sutton. Ligaments. - 1.25 
 Wickes. Sepulture. - 1.50 
 
 NERVOUS DISEASES, Etc. 
 Buzzard. Ner. Affections. 5.00 
 Flower. Atlas of Nerves. 3.50 
 Gowers. Manual of. In r vol. - 
 
 - Dis. of Spinal Cord. - 
 - Diseases of Brain. 2.00 
 
 - Epilepsy. - - - 
 Page. Injuries of Spine. 3.50 
 Radcliffe. Epilepsy, Pain, etc. 1.25 
 Wilks. Nervous Diseases. 6.00 
 
 NURSING. 
 
 Brush, Nursing of the Insane. - 
 Cullingworth. Manual of. i.oo 
 Monthly Nursing. 
 
 .50 
 .75 
 i.oo 
 i.oo 
 .50 
 
 Domville's Manual 
 Hood. Lectures to Nurses. 
 Liickes. Hospital Sisters. 
 Temperature Charts. - 
 
 OBSTETRICS. 
 Bar. Antiseptic Obstet. 
 Barnes. Obstetric Operations. 3.75 
 Cazeaux and Tarnier. New 
 
 Ed. Colored Plates. - n.oo 
 Galabin's Manual of. - 
 Glisan's Text-book. 2d Ed 
 Landis. Compend. - 
 Meadows. Manual. - 
 Rigby. Obstetric Mem. 
 Schultze. Diagrams. - 
 Tyler Smith's Treatise. 
 Swayne's Aphorisms - 
 
 OSTEOLOGY. 
 Holden's Text-book. - 
 PATHOLOGY & HISTOLOGY. 
 Aitken. The Ptomaines, etc. i.oo 
 Bowlby. Surgical Path. 2.00 
 Gibbes. Practical. - 1.75 
 
 Gilliam. Essentials of. - 2.00 
 Paget's Surgical Path. - 7.00 
 Rindfleisch. General. 2.00 
 
 Sutton. General Path. - 4.50 
 Virchow. Post-mortems. i.oo 
 
 - Cell. Pathology. - 4.00 
 Wilkes and Moxon. - 6.00 
 
 PHARMACY. 
 Beasley's Druggists' Rec'ts. 2.25 
 
 - Formulary. - - 2.25 
 Fliickiger. Cinchona Barks. 1.50 
 Kirby. Pharm. of Remedies. 2.25 
 Mackenzie. Phar. of Throat. 1.25 
 Merrell's Digest. - - 4.00 
 
 1.75 
 
 3.00 
 
 4.00 
 
 i.oo 
 
 2.00 
 
 .50 
 
 25.00 
 
 4.00 
 
 1.25 
 
 6.00 
 
 Piesse. Perfumery. - 5-5<> 
 Proctor. Practical Pharm. 4.50 
 Roberts. Compend of. 2.00 
 
 Stewart's Compend. 2d Ed. i.oo 
 Tuson. Veterinary Pharm. 2.50 
 
 PHYSICAL DIAGNOSIS. 
 Bruen's Handbook. 2d Ed. i 50 
 
 PHYSIOLOGY. 
 
 Beale's Bioplasm. - - 2.25 
 Brubaker's Compend. Illus. 
 
 4th Ed. - i.oo 
 
 Kirkes' nth Ed. (Author's 
 
 Ed.) Cloth, 4.00; Sheep, 5.00 
 
 Landois' Text-book. 2d Ed. 6.50 
 
 Sanderson's Laboratory B'k. 5.00 
 
 Tyson's Cell Doctrine. - 2.00 
 
 Yeo's Manual, zd Ed. CL, 3.00 ; 
 
 Sheep, 3.50 
 
 POISONS. 
 
 Aitken. The Ptomaines, etc. i.oo 
 Black. Formation of. - i 50 
 
 Reese. Toxicology. - 4.00 
 Tanner. Memoranda of. .75 
 
 PRACTICE. 
 
 Beale. Slight Ailments. 1.25 
 
 Charteris. Handbook of. 1.25 
 Fagge's Practice. 2 Vols. 10.00 
 Fenwick's Outlines of. - 1.25 
 Hughes. Compend of. 2 Pts. 2.00 
 Physician's Ed. Inset, i Vol. 2.50 
 Roberts. Text-book. New 
 
 Ed. .... 5.00 
 Tanner's Index of Diseases. 3.00 
 Warner's Case Taking. 1.75 
 
 PRESCRIPTION BOOKS. 
 Beasley's 3000 Prescriptions. 2.25 
 
 Receipt Book. - 2.25 
 
 Formulary. - - 2.25 
 
 Pereira's Pocket-book. i.oo 
 
 Wythe's Dose and Symptom 
 
 Book. 1 7th Ed. Just out. \.oo 
 
 RECTUM AND ANUS. 
 Allingham. Diseases of. 1.25 
 
 SKIN AND HAIR. 
 Anderson's Text-Book. 4.50 
 
 Bulkley. The Skin. - .50 
 
 Cobbold. Parasites. - 5-0 
 Van Harlingen. Diagnosis 
 
 and Treatment of Skin Dis. 1.75 
 Wilson. Skin and Hair. i.oo 
 STIMULANTS & NARCOTICS. 
 Hare, Tobacco. Paper, .50 
 
 Kane. Opium Habit, etc. 1.25 
 
 Kerr. Inebriety. - - 
 
 Lizars. On Tobacco. - .50 
 
 Miller. On Alcohol - .50 
 
 Parrish. Inebriety. - 1.25 
 
 SURGERY. 
 Butlin. Surg. of Malignant 
 
 Diseases. ... 4.00 
 Gamgee. Wounds and Frac- 
 tures. - - - - 3-5 
 Heath's Operative. - 12.00 
 
 Minor. 8th Ed. - 2.00 
 
 Diseases of Jaws. 4.50 
 
 Horwitz. Compend. 3d Ed. i.oo 
 
 Jacobson. Operative Surg. 
 
 Porter's Surgeon's Pocket- 
 book. - 2.25 
 
 Pye. Surgical Handicraft. 5.00 
 Roberts. Surgical Delusions. .50 
 
 (A. S.) Club-Foot. .50 
 
 Smith. Abdominal Surg. 
 
 Swain. Surg. Emergencies. 1.50 
 Walsham. Practical Surg. 3 oo 
 Watson's Amputations. 5.50 
 
 TECHNOLOGICAL BOOKS. 
 
 See also Chemistry. 
 Cameron. Oils & Varnishes. 2.50 
 Gardner. Brewing, etc. 1.75 
 
 Gardner. Acetic Acid, etc. 1.75 
 
 Bleaching & Dyeing. 1.75 
 
 Overman. Mineralogy. i.oo 
 Piesse. Perfumery, etc. 5.50 
 Piggott. On Copper. - i.oo 
 Thompson. Physics. - 
 
 THERAPEUTICS. 
 Biddle. icth Ed. - - 4.00 
 Cohen. Inhalations. - 1.25 
 Field. Cathartics and Emetics. 1.75 
 Headland. Action of Med. 3.00 
 Kirby. Selected Remedies. 2.25 
 Kidd. Laws of. - - 1.25 
 Mays. Therap. Forces. 1.25 
 
 Ott. Action of Medicines. 2.00 
 Phillips. Vegetable. - 7.50 
 Potter's Compend. - i.oo 
 
 -, Handbook of. 3.00; Sh. 3. 50 
 
 Starr, Walker and Powell. 
 
 Phys. Action of Meds. - .75 
 
 Waring's Practical. - 3.00 
 
 THROAT AND NOSE. 
 Cohen. Throat and Voice. .50 
 
 Inhalations. - 1.25 
 
 Greenhow. Bronchitis. 1.25 
 
 James. Sore Throat - 1.25 
 Journal of Laryngology. 3.00 
 Mackenzie. Throat and Nose." 
 
 New Ed. Complete in one 
 vol. New Illus., etc. - 
 
 The OZsophagus, Naso- 
 Pharynx, etc. - 3.00 
 
 Larynx. - - 1.25 
 
 Pharmacopoeia. - 1.25 
 
 Potter. Stammering, etc. i.oo 
 Woakes. Post-Nasal Catarrh. 1.50 
 
 Nasal Polypus, etc. 1.25 
 
 Deafness, Giddiness, etc. 
 
 TRANSACTIONS AND 
 
 REPORTS. 
 
 Penna. Hospital Reports. 1.25 
 Power and Holmes' Reports. 1.25 
 Trans. College of Physicians. 3.50 
 Amer. Surg. Assoc. 4.00 
 
 URINE & URINARY ORGANS. 
 Acton. Repro. Organs. 2.00 
 
 Beale. Urin. & Renal Dis. 1.75 
 
 Urin. Deposits. Plates. 2.00 
 
 Holland. The Urine. - .50 
 
 kegg. On Urine. - - .75 
 
 Marshall and Smith. Urine, i.oo 
 Ralfe. Kidney and Uri. Org. 2.75 
 Thompson. Urinary Organs. 1.25 
 
 Surg. of Urin. Organs. 1.25 
 
 - Calculous Dis. - i.oo 
 
 Lithotomy. - - 3.50 
 
 Prostate. 6th Ed. 2.00 
 
 Tyson. Exam, of Urine. 1.50 
 
 Van Niiys. Urine Analysis. 
 
 VENEREAL DISEASES. 
 Cooper. Syphilis. - - 3.50 
 Durkee. Gonorrhoea. - 3.50 
 Hill and Cooper's Manual, i.oo 
 Lewin. Syphilis. - - 1.25 
 
 VETERINARY PRACTICE. 
 Tuson's Vet. Pharmacopoeia. 2.50 
 
 VISITING LISTS. 
 Lindsay and Blakiston's 
 Regular Edition. i.oo to 3.00 
 
 Perpetual Edition. 1.25 
 
 WATER. 
 
 Fox. Water, Air, Food. 4.00 
 
 Frankland. Analysis of. i.oo 
 
 MacDonald. 
 
 2-75 
 
 WOMEN, DISEASES OF. 
 Byford's Text-book. 4th Ed. 5.00 
 -- Uterus. ... j.25 
 Dillnberger. and Children. 1.50 
 Doran. Gynaec. Operations. 4.50 
 Duncan. Sterility. - 2.00 
 Galabin. Diseases of. - ? oo 
 Hodge. Note Book for 
 
 Tumors. ... <50 
 
 Morris. Compend. - i.oo 
 Savage. Pelvic Organs. 12.00 
 Scanzoni. Sexual Organs of. 4.00 
 Tilt. Change of Life. - 1.2=; 
 Winckel, by Parvin. Manual 
 
 of. Illus. Clo.,3.oo; Sh. 3.50 
 
FAGGE'S PRACTICE. 
 
 THE PRINCIPLES AND PRACTICE OF MEDICINE. By C. HILTON 
 FAGGE, M.D., F.R.C.P., F.R.M.C.S., Examiner in Medicine, University of Lon- 
 don; Physician to, and Lecturer on Pathology in, Guy's Hospital; Senior 
 Physician to Evelina Hospital for Sick Children, etc. Arranged for the press 
 by P. H. PYE- SMITH, M.D., Lect. on Medicine in Guy's Hospital. Including 
 a section on Cutaneous Affections, by the Editor ; chapter on Cardiac Dis- 
 eases, by SAMUEL WILKES, M.D., F.R.S., with a very complete Index of 
 Authors and one of Subjects, by ROBERT EDMUND CARRINGTON. 
 
 Two Volumes. Royal Octavo. 1900 Pages. 
 
 SOLD BY SUBSCRIPTION ONLY. 
 
 Handsome Cloth, $10.00. Full Leather, Raised Boards, $12.00. 
 One-Half Russia, $14.00. One-Half Morocco, $14.00. 
 
 This work on the Practice of Medicine is based on laborious researches into 
 the pathological and clinical records of Guy's Hospital, London, during the 
 twenty years in which the author held office there as Medical Registrar, as Patholo- 
 gist, and as Physician. Familiar, beyond most, if not all, of his contemporaries, 
 with modern medical literature, a diligent reader of French and German periodi- 
 cals, Dr. Fagge, with his remarkably retentive memory and methodical habits, 
 was able to bring to his work of collection and criticism almost unequaled 
 opportunities of extensive experience in the wards and dead house. The result 
 is that which will probably be admitted to be a fuller, more original, and more 
 elaborate text-book on medicine than has yet appeared. It is the first of import- 
 ance emanating from Guy's Hospital, and the only two-volume work on the 
 Practice of Medicine that has been issued for a number of years. Several subjects , 
 such as Syphilis, that are usually omitted or but slightly spoken of in a general 
 work of this character, receive full attention. The section on Nervous Diseases is 
 very exhaustive, and that on Diseases of the Respiratory Organs and Larynx are 
 equally full. The author has adopted a very simple and practical plan in the 
 treatment of Lung Diseases, and Phthisis receives full consideration. The chapter 
 on Cardiac Diseases, by Dr. Sam'l Wilkes, is most carefully written, and the 
 parts devoted to Cutaneous Affections, by Dr. Pye-Smith, are excellent. 
 
 PRESS NOTICES. 
 
 " Those who have read Guy's Hospital Reports for the past twenty years arid the many articles in the 
 different English journals from the pen of Charles Hilton Fagge will expect a comprehensive, carefully- 
 prepared and painstaking volume. They will not be disappointed. One cannot proceed far in the reading 
 of this book before he is impressed with certain features of it which are very remarkable. Let him turn to 
 almost any page at random, and he is likely to find reference made to a dozen authors; the authors being, 
 perhaps, of three or four different nationalities. The author is said to have been very familiar with German, 
 French and Italian, which, with his own English, would give him four different languages from which to 
 cull his information. His memory must have been marvelous, and he was an original worker and thinker. 
 We close the first volume feeling that here was a master. * * * Will take and hold the very 
 front rank among works on the practice of medicine. * * * A general and complete index to both volumes 
 adds great value to its usefulness. One is gratified to find reference to no fewer than thirty American authors. 
 Certainly these two volumes make a complete work on practice, whether as a book of reference or even as a 
 text-book. It is in style worthy of a second place only to the classical work of Sir Thomas Watson." New 
 York Medu:al Journal. 
 
 " If the second volume of this treatise fulfills the promise of excellence contained in the one before us 
 the entire work cannot fail to find favor with the profession both here and abroad." New York Medical 
 Record, notice of Vol. I. 
 
 "The finest of all treatises on the healing art. It should be in every physician's library." Cincinnati 
 Lancet and Clinic. 
 
 " A perusal of its pages shows that it is one of the most scientific and philosophical works of its kind, 
 being, in truth, a mine of clinical and pathological facts, which are dealt with in so masterly a manner that 
 we know not which to admire most the patient labor and thought expended in bringing them to light, the 
 learning and acumen that illustrate them, or the calm and judicial spirit in which they are estimated and 
 criticised." London Lancet. 
 
 "The work is an English classic. * * * His great treatise remains a monument more enduring than 
 fame." Dublin Journal of Medicine. 
 
 TERMS. This work is published by subscription ; in order, however, to receive it promptly, subscrip- 
 tions should be sent direct to the publishers, or through your regular bookseller, when the book will be 
 shipped, carefully packed, to your address, express charges or postage prepaid. 
 
 P. BLAKISTON, SON & CO., /oi2 Walnut St., Philadelphia. 
 
P. BLAKISTON, SON & CO.'S 
 JVJedical and Scientific publications, 
 
 No. 1012 WALNUT ST., PHILADELPHIA. 
 
 ABERCROMBIE. Medical Jurisprudence, for Medical and Legal Students and 
 Practitioners. By JOHN ABERCROMBIE, M.D. 387 pages. Cloth, $2.50 
 
 ACTON. The Functions and Disorders of the Reproductive Organs in Child- 
 hood, Youth, Adult Age and Advanced Life, considered in their Physiological, 
 Social and Moral Relations. By WILLIAM ACTON, M.D., M.R.C.S. Sixth Edition. 
 8vo. Cloth, $2.00 
 
 AITKEN. Animal Alkaloids, the Ptomaines, Leucomaines and Extractives in 
 their Pathological Relations. A short summary of "recent researches as to the 
 origin of some diseases by or through the physiological processes going on 
 during life. By WILLIAM AITKEN, M.D., F.R.S., Professor of Pathology in the 
 Army Medical School, Netley, England. Cloth, $1.00 
 
 ALLEN. Commercial Organic Analysis. A Treatise on the Modes of Assaying 
 the Various Organic Chemicals and Products employed in the Arts, Manufactures, 
 Medicine, etc., with Concise Methods for the Detection of Impurities, Adultera- 
 tions, etc. Second Edition. Revised and Enlarged. By ALFRED ALLEN, F.C.S. 
 Vol. I. Alcohols, Ethers, Vegetable Acids. Starch and its Isomers. etc. 
 
 $4.50 
 
 Vol. II. Fixed Oils and Fats, Hydrocarbons and Mineral Oils, Phenols and 
 
 their Derivatives, Coloring Matters, etc. $5.00 
 
 Vol. III. Cyanogen Compounds, Alkaloids, Animal Products, etc. In Press. 
 
 ALLEN'S New Method of Recording the Motions of the Soft Palate. By HARRISON- 
 ALLEN, M.D., Professor of Physiology University of Pennsylvania. Cloth, .50 
 
 ALLINGHAM. Diseases of the Rectum. Fistula, Haemorrhoids, Painful Ulcer, 
 Stricture, Prolapsus, and other Diseases of the Rectum, their Diagnosis and 
 Treatment. By WILLIAM ALLINGHAM, F.R.C.S. Fourth Edition, Enlarged. 
 Illustrated. 8vo. Paper covers, .75 ; Cloth, $1.25 
 
 ALTHATTS. Medical Electricity. Theoretical and Practical. Its Use in the Treat- 
 ment of Paralysis, Neuralgia, and other Diseases. By JULIUS ALTHAUS, M.D. 
 Third Edition, Enlarged. 246 Illustrations. 8vo. Cloth, $6.00 
 
 ANDERSON. A Treatise on Skin Diseases. With special reference to Diagnosis 
 and Treatment, and including an Analysis of ii.ooo consecutive cases. By T. 
 McCALL ANDERSON, M.D., Professor of Clinical Medicine, University of Georgia. 
 With several Full Page Plates, two of which are Colored Lithographs, and nu- 
 merous Wood Engravings. Octavo. 650 pages. Cloth, $4.50; Leather, $5.50 
 
 ARLT. Diseases of the Eye. Clinical Studies on Diseases of the Eye. Including the 
 Conjunctiva, Cornea and Sclerotic, Iris and Ciliary Body. By Dr. FERD. RITTER 
 VON ARLT, University of Vienna. Authorized Translation by LYMAN WARE, 
 M.D., Surgeon to the Illinois Charitable Eye and Ear Infirmary, Chicago. 
 Illustrated. 8vo. Cloth. $2.50 
 
 BAR. Antiseptic Midwifery, The Principles of Antiseptic Methods Applied to 
 Obstetric Practice. By Dr. PAUL BAR, Obstetrician to, formerly Interne in, the 
 Maternity Hospital, Paris. Authorized Translation by HENRY D. FRY, M.D., 
 with an Appendix by the author. Octavo. Cloth, 1.75 
 
 BALFOTTR. Clinical Lectures on Diseases of the Heart and Aorta. By G. W. 
 
 BALFOUR, M.D. Illustrated. Second Edition. Cloth, $5.00 
 
 5 
 
6 P. BLAKISTON, SON &* CO.'S 
 
 BARNES. Lectures on Obstetric Operations, including the Treatment of Hemor- 
 rhage, and forming a Guide to Difficult Labor. By ROBERT BARNES, M.D., 
 F.R.C.P. Fourth Edition. Illustrated. 8vo. Cloth, 3.7 5 
 
 BARRETT. Dental Surgery for General Practitioners and Students of Medicine 
 and Dentistry. Extraction of Teeth, etc. By A. W. BARRETT, M.D. Illustrated. 
 
 Cloth, $1.00 
 
 BARTLEY. Medical Chemistry. A Text-book for Medical and Pharmaceutical 
 Students. By E. H. BARTLEY, M.D., Professor of Chemistry and Toxicology at the 
 Long Island College Hospital; President of the American Society of Public 
 Analysts ; Chief Chemist, Board of Health, of Brooklyn, N. Y. With Illustra- 
 tions, Glossary and Complete Index. I2mo. Cloth, $2.50 
 
 BEALE. On Slight Ailments ; their Nature and Treatment. By LIONEL S. BEALE, 
 
 M.D., F.R.S., Professor of Practice, King's Medical College, London. Second 
 
 Edition. Enlarged and Illustrated. Paper covers, .75 ; Cloth, $1.25 
 
 Urinary and Renal Diseases and Calculous Disorders. Hints on Diagnosis 
 
 and Treatment. Demi-8vo. 356 pages. Cloth, $1.75 
 
 The Use of the Microscope in Practical Medicine. For Students and 
 
 Practitioners, with full directions for examining the various secretions, etc., 
 
 in the Microscope. Fourth Edition. 500 Illustrations. 8vo. Cloth, $7.50 
 
 How tp Work with the Microscope. A Complete Manual of Microscopical 
 Manipulation, containing a full description of many new processes of 
 investigation, with directions for examining objects under the highest 
 powers, and for taking photographs of microscopic objects. Fifth Edition. 
 Containing over 400 Illustrations, many of them colored. 8vo. Cloth, $7.50 
 Bioplasm. A Contribution to the Physiology of Life, or an Introduction to the 
 Study of Physiology and Medicine, for Students. With numerous Illus- 
 trations. Cloth, $2.25 
 Life Theories and Religious Thought. Six Colored Plates. Cloth, $2.00 
 On Life and Vital Action in Health and Disease. i2mo. Cloth, $2.00 
 One Hundred Urinary Deposits, on eight sheets, for the Hospital, Labora- 
 tory, or Surgery. New Edition. 4to. Paper, $2.00 
 
 BEASLEY'S Book of Prescriptions. Containing over 3100 Prescriptions, collected 
 from the Practice of the most Eminent Physicians and Surgeons English, 
 French and American ; a Compendious History of the Materia Medica, Lists of 
 the Doses of all Officinal and Established Preparations, and an Index of Diseases 
 and their Remedies. By HENRY BEASLEY. Sixth Edition. Revised and 
 Enlarged. Cloth, $2.25 
 
 Druggists' General Receipt Book. Comprising a copious Veterinary Formu- 
 lary ; Recipes in Patent and Proprietary Medicines, Druggists' Nostrums, 
 etc.; Perfumery and Cosmetics ; Beverages, Dietetic Articles and Condi- 
 ments ; Trade Chemicals, Scientific Processes, and an Appendix of Useful 
 Tables. Ninth Edition. Revised. Cloth, $2.25 
 
 Pocket Formulary and Synopsis of the British and Foreign Pharmacopoeias. 
 Comprising Standard and Approved Formulae for the Preparations and 
 Compounds Employed in Medical Practice. Eleventh Edition. Cloth, $2.25 
 
 BENTLEY AND TRIMEN'S Medicinal Plants. A New Illustrated Work, con- 
 taining full botanical descriptions, with an account of the properties and uses of 
 the principal plants employed in medicine, especial attention being paid to those 
 which are officinal in the British and United States Pharmacopoeias. The plants 
 which supply food and substances required by the sick and convalescent are also 
 included. By R. BENTLEY, F.R.S., Professor of Botany, King's College, London, 
 and H. TRIMEN, M.B., F.H.S., Department of Botany, British Museum. Each 
 species illustrated by a colored plate drawn from nature. In forty-two parts. 
 Eight colored plates in each part. 
 
 Price reduced to $1.50 per part, or the complete work handsomely bound 
 in 4 volumes. Half Morocco, Gilt, $75.00. 
 
MEDICAL AND SCIENTIFIC PUBLICATIONS. 7 
 
 BIBLE HYGIENE ; or Health Hints. By a physician. Written to impart in a 
 popular and condensed form the elements of Hygiene ; showing how varied and 
 important are the Health Hints contained in the Bible, and to prove that the 
 secondary tendency of modern Philosophy runs in a parallel direction with the 
 primary light of the Bible. I2mo. Cloth, 1.00 
 
 BIDDLE'S Materia Medica and Therapeutics. Tenth Edition. For the Use of 
 Students and Physicians. By Prof. JOHN B. BIDDLE, M.D., Professor of Materia 
 Medica in Jefferson Medical College, Philadelphia. The Tenth Edition, Thor- 
 oughly revised, and in many parts rewritten, by his son, CLEMENT BIDDLE, M.D., 
 Assistant Surgeon, U. S. Navy, and HENRY MORRIS, M.D., Demonstrator of 
 Obstetrics in Jefferson Medical College, Fellow of the College of Physicians, of 
 Philadelphia, etc. The Botanical portions have been curtailed or left out, and 
 the other sections, on Therapeutics and the Physiological action of Drugs, greatly 
 enlarged. Cloth, $4.00; Leather, $4.75 
 
 BLACK. Micro-Organisms. The Formation of Poisons by Micro-Organisms. A 
 Biological study of the Germ Theory of Disease. By G. V. BLACK, M.D., D.D.S. 
 
 Cloth, $1.50 
 
 BLOXAM. Chemistry, Inorganic and Organic. With Experiments. By 
 CHARLES L. BLOXAM, Professor of Chemistry in King's College, London, and in 
 the Department for Artillery Studies, Woolwich. Sixth Edition. Revised. With 
 nearly 300 Engravings. 8vo. Cloth, $3.75 ; Leather, $4.75 
 
 Laboratory Teaching. Progressive Exercises in Practical Chemistry. In- 
 tended for use in the Chemical Laboratory, by those who are commencing 
 the study of Practical Chemistry. 4th Edition. 89 Illus. Cloth, $1.75 
 
 BOWLBY. Surgical Pathology and Morbid Anatomy. By ANTHONY A. 
 BOWLBY, F.R.C.S., Surgical Register and Demonstrator of Surgical Pathology to 
 St. Bartholomew's Hospital, etc. 135 Illustrations. Cloth, $2.00 
 
 BOWMAN. Practical Chemistry, including analysis, with about 100 Illustrations. 
 By Prof. JOHN E. BOWMAN. Eighth English Edition. Revised by Prof. BLOXAM, 
 Professor of Chemistry, King's College, London. Cloth, $2.00 
 
 BRATJNE. Atlas of Topographical Anatomy. Thirty-four Full-page Plates, 
 Photographed on Stone, from Plane Sections of Frozen Bodies, with many other 
 illustrations. By WILHELM BRAUNE, Professor of Anatomy at Leipzig. Trans- 
 lated and Edited by EDWARD BELLAMY, F.R.C.S., Lecturer on Anatomy, Char- 
 ing Cross Hospital, London. 4to. Cloth, $8.00 
 
 BRTJBAKER. Physiology. A Compend of Physiology, specially adapted for the 
 use of Students and Physicians. By A. P. BRUBAKER, M.D., Demonstrator of 
 Physiology at Jefferson Medical College, Prof, of Physiology, Penn'a College of 
 Dental Surgery, Philadelphia. Fourth Edition. Revised, Enlarged and Illus- 
 trated. No. 4,? Quiz- Compend Series? 12 mo. Cloth, $1.00 
 
 Interleaved for the addition of notes, $1.25 
 
 BRTTEN. Physical Diagnosis. For Physicians and Students. By EDWARD T. 
 BRUEK, M.D., Asst. Professor of Physical Diagnosis in the University of Pennsyl- 
 vania. Illustrated by Original Wood Engravings. I2mo. 2d Ed. Cloth, $1.50 
 
 BRUSH, Manual for Attendants on the Insane. A manual for the Instruction of 
 Attendants and Nurses in Hospitals for the Insane. By EDWARD N. BRUSH, 
 M.D., Senior assistant Physician, Department of Males, Pennsylvania Hospital for 
 Insane, Philadelphia ; Late Senior Ass't. Physician N. Y. State Lunatic Asylum, 
 Utica. Including lectures on Anatomy, Chemistry, Physiology, Hygiene, etc. 
 I2mo. Cloth. 
 
 BTJCKNILL AND TTJKE'S Manual of Psychological Medicine : containing 
 the Lunacy Laws, the Nosology, ^Etiology, Statistics, Description, Diagnosis, 
 Pathology (including morbid Histology) and Treatment of Insanity. By JOHN 
 CHARLES BUCKNILL, M.D., F.R.S., and DANIEL HACK TUKE, M.D., F.R.C.P. 
 Fourth Edition, much enlarged, with twelve lithographic and numerous other 
 illustrations. 8vo. Cloth, $8.00 
 
P. BLAKISTON, SON 6- CO.'S 
 
 BULKLEY. The Skin in Health and Disease. By L. DUNCAN BULKLEY, M.D., 
 Attending Physician at the New York Hospital. Illustrated. Cloth, .50 
 
 BURDETT'S Cottage Hospitals. General, Fever and Convalescent; their Prog- 
 ress, Management and Work. By HENRY C. BURDETT, M.D. Second Edition. 
 Rewritten and Enlarged, with Plans and Illustrations. Crown 8vo. Cloth, $4.50 
 
 BUXTON. On Anaesthetics. A Manual. By DUDLEY WILMOT BUXTON, M.R.C.S., 
 
 %I.R.C.P., Asst. to Prof, of Med., and Administrator of Anaesthetics, University 
 
 College Hospital, London. Practical Series. Nearly Ready. 
 
 BURNETT. Hearing, and How to Keep It. By CHAS. H. BURNETT, M.D., Prof, 
 of Diseases of the Ear, at the Philadelphia Polyclinic. Illustrated. Cloth, .50 
 
 BUTLIN. Operative Surgery of Malignant Diseases. By HENRY T. BUTLIN, 
 Asst. Surg. to St. Bartholomew's Hospital, London, etc. Cloth, $4.00 
 
 BUZZARD. Clinical Lectures on Diseases of the Nervous System. By THOS. 
 BUZZARD, M.D. Illustrated. Octavo. Cloth, $5.00 
 
 BYFORD. Diseases of Women. The Practice of Medicine and Surgery, as 
 applied to the Diseases and Accidents Incident to Women. By W. H. BYFORD, 
 A.M., M.D., Professor of Gynaecology in Rush Medical College and of Obstetrics 
 in the Woman's Medical College; Surgeon to the Woman's Hospital ; Ex-Presi- 
 dent American Gynaecological Society, etc., and HENRY T. BYFORD, M.D., Sur- 
 geon to the Woman's Hospital of Chicago ; Gynaecologist to St. Luke's Hos- 
 pital ; President Chicago Gynaecological Society, etc. Fourth Edition. Revised, 
 Rewritten and Enlarged. With 306 Illustrations, over 100 of which are original. 
 Octavo. 832 pages. Cloth, $5.00 ; Leather, $6.00 
 
 On the Uterus. Chronic Inflammation and Displacement. Cloth, $1.25 
 
 CARPENTER. The Microscope and Its Revelations. By W. B. CARPENTER, 
 M.D., F.R.S. Sixth Edition. Revised and Enlarged, with over 500 Illustrations 
 and Lithographs. Cloth, $5.50 
 
 CARTER. Eyesight, Good and Bad. A Treatise on the Exercise and Preservation 
 of Vision. By ROBERT BRUDENELL CARTER, F.R.C.S. Second Edition, with 50 
 Illustrations, Test Types, etc. I2mo. Paper, .75 ; Cloth, $1.25 
 
 CAZEAUX and TARNIER'S Midwifery. With Appendix, by Mund<. Eighth 
 Revised and Enlarged Edition. With Colored Plates and numerous other 
 Illustrations. The Theory and Practice of Obstetrics ; including the Diseases 
 of Pregnancy and Parturition, Obstetrical Operations, etc. By P. CAZEAUX, 
 Member of the Imperial Academy of Medicine, Adjunct Professor in the Faculty 
 of Medicine in Paris. Remodeled and rearranged, with revisions and additions, 
 by S. TARNIER, M.D., Professor of Obstetrics and Diseases of Women and 
 Children in the Faculty of Medicine of Paris. Eighth American, from the 
 Eighth French and First Italian Edition. Edited and Enlarged by ROBERT 
 J. HESS, M.D., Physician to the Northern Dispensary, Phila., etc., with an Ap- 
 pendix by PAUL F. MUNDE, M.D., Professor of Gynaecology at the New York 
 Polyclinic, and at Dartmouth College ; Vice-President American Gynaecological 
 Society, etc. Illustrated by Chromo-Lithographs, Lithographs, and other Full- 
 page Plates, seven of which are beautifully colored, and numerous Wood En- 
 gravings. Two Volumes, Royal Square octavo. 1221 pages. 
 
 Cloth, $11.00; Full Leather, $13.00 ; Half Russia or Half Morocco, $15.00. 
 Sold only by Subscription. F^lll Circulars and Information upon Application. 
 
 CHARTERIS. The Practice of Medicine. A Handbook. By M. CHARTERIS, 
 M.D., Member of Hospital Staff and Professor in University of Glasgow. With 
 Microscopic and other Illustrations. Cloth, $1.25 
 
 Materia Medica and Therapeutics. A Manual for Students. In Press. 
 
 CHAVASSE. The Mental Culture and Training of Children. By PYE HENRY 
 CHAVASSE. i2mo. Cloth, $1.00 
 
MEDICAL AND SCIENTIFIC PUBLICATIONS. 9 
 
 CHURCHILL. Face and Foot Deformities. By FRED. CHURCHILL, M.D., 
 Ass't Surgeon to the Victoria Hospital for Sick Children, London. Six Plain 
 and Two Colored Lithographs. 8vo. Cloth, $3.50 
 
 CLEVELAND'S Pocket Dictionary. A Pronouncing Medical Lexicon, containing 
 correct Pronunciation and Definition of terms used in medicine and the col- 
 lateral sciences, abbreviations used in prescriptions, list of poisons, their anti- 
 dotes, etc. By C, H. CLEVELAND, M.D. Thirty-second Edition. Very small 
 pocket size. Cloth, .75; Tucks with Pocket, $1.00 
 
 COBBOLD. A Treatise on the Entozoa of Man and Animals, including some 
 account of the Ectozoa. By T. SPENCER COBBOLD, M.D., F.R.S. With 85 Illus- 
 trations. 8vo. Cloth, $5.00 
 
 COHEN on Inhalation, its Therapeutics and Practice, including a Description of 
 the Apparatus Employed, etc. By J. SOLIS-COHEN, M.D. With cases and Illus- 
 trations. A New Enlarged Edition. I2mo. Paper, .75; Cloth, $1.25 
 The Throat and Voice. Illustrated. i2mo. Cloth, .50 
 
 COLES. Deformities of the Month, Congenital and Acquired, with Their Me- 
 chanical Treatment. By OAKLEY COLES, M.D., D.D.S. Third Edition. 83 Wood 
 Engravings and 96 Drawings on Stone. 8vo. Cloth, $4.50 
 
 COOPER on Syphilis and Pseudo-Syphilis. By ALFRED COOPER, F.R.C.S., Sur- 
 
 ;on to the Lock Hospital, to St. Marks, and to the West London Hospitals, 
 ctavo. Cloth, $3.50 
 
 COLLIE, On Fevers. A Practical Treatise on Fevers, Their History, Etiology, 
 Diagnosis, Prognosis and Treatment. By ALEXANDER COLLIE, M.D., M.R.C.P., 
 Lond. Medical Officer Homerton Fever Hospital, and of the London Fever 
 Hospital. With Colored Plates. Being Volume 5, Practical Series. Cloth, $2 50 
 
 CULLINGWORTH. A Manual of Nursing, Medical and Surgical. By CHARLES 
 J. CULLINGWORTH, M.D., Physician to St. Mary's Hospital, Manchester, England. 
 Second Edition. With 18 Illustrations. I2mo. Cloth, $1.00 
 
 A Manual for Monthly Nurses. Third Edition. 321110. Cloth, .50 
 
 DAGTJENET'S Ophthalmoscopy. A Manual for the Use of Students. By Dr. 
 DAGUENET. Translated from the French, by Dr. C. S. JEAFFERSON, F.R.C.S.E. 
 Illustrated. I2mo. Cloth, $1.50 
 
 DAY. Diseases of Children. A Practical and Systematic Treatise for Practitioners 
 
 and Students. By Wm. H. DAY, M.D. Second Edition. Rewritten and very 
 
 much Enlarged. 8vo. 752pp. Price reduced. Cloth, $3.00; Sheep, $4.00 
 
 On Headaches. The Nature, Causes and Treatment of Headaches. Fourth 
 
 Edition. Illustrated. 8vo. Paper, .75 ; Cloth, $1.25 
 
 DILLNBERGER. On Women and Children. The Treatment of the Diseases Pecu- 
 liar to Women and Children. By Dr. EMIL DILLNBERGER. i2mo. Cloth, 31.50 
 
 DOMVILLE. Manual for Nurses and others engaged in attending to the sick. By 
 Ed. J. Domville, M.D. Fifth Ed. With Recipes for Sick-room Cookery, etc. 
 
 Cloth, .75 
 
 DORAN. Gynaecological Operations. A Hand-book. By ALBAN DORAN, F.R.C.S., 
 Asst. Surg. to the Samaritan Free Hospital for Women and Children, London. 
 166 Illustrations. 8vo. Cloth, 4.50 
 
 DULLES. What to Do First, In Accidents and Poisoning. By C. W. DULLES, M.D. 
 Second Edition, Enlarged, with new Illustrations. Cloth, .75 
 
 DUNCAN, On Sterility in Women, By J. MATHEWS DUNCAN, M.D., LL.D., Obstetric 
 Physician to St. Bartholomew's Hospital, etc. Octavo. Cloth, $2.00 
 
 DURKEE, On Gonorrhea and Syphilis. By SILAS DURKEE, M.D. Sixth Edition. 
 Revised and Enlarged, with Portrait and Eight Colored Illustrations. Cloth, $3.50 
 
10 P. BLAKISTON, SON &* CO:S 
 
 ELLIS. What Every Mother Should Know, By EDWARD ELLIS, M.D., late 
 Physician to the Victoria Hospital for Children, London. I2mo. Cloth, .75 
 
 EDWARDS. Blight's Disease. How a Person Affected with Bright' s Disease 
 
 Ought to Live. By Jos. F. EDWARDS, M.D. 2d Ed. Reduced to Cloth, .50 
 
 Malaria: What It Means; How to Escape It; Its Symptoms; When and 
 
 Where to Look For It. Price Reduced to Cloth, .50 
 
 Vaccination and Smallpox. Showing the Reasons in favor of Vaccination, 
 
 and the Fallacy of the Arguments advanced against it, with Hints on the 
 
 Management and Care of Smallpox patients. Cloth, .50 
 
 FAGGE. The Principles and Practice of Medicine. By C. HILTON FAGGE, M.D., 
 F.R.C.P.,F.R.M.C.S., Examiner in Medicine, University of London; Physician to, 
 and Lecturer on Pathology in, Guy's Hospital ; Senior Physician to Evelina Hos- 
 pital for Sick Children, etc. Arranged for the press by PHILIP H. PYE-SMITH, 
 M.D., Lect. on Medicine in Guy's Hospital. Including a section on Cutaneous 
 Affections, by the Editor; Chapter on Cardiac Diseases, by SAMUEL WILKES, M.D., 
 F.R.S., and Complete Indexes by ROBERT EDMUND CARRINGTON. 2 vols. Royal 
 Svo. Cloth, $10.00; Leather, $12.00 ; Half Russia, $14.00. 
 
 " Certainly these two volumes make a complete work on practice, whether as a book of reference or even as 
 a text-book. It is in style worthy of a second place only to the classical work of Sir Thomas Watson." New 
 York Medical Journal. 
 
 " The finest of all treatises on the healing art. It should be in every physician's library." Cincinnati 
 Lancet and Clinic. 
 
 Sold only by subscription. Fiill information upon application to the Publishers. 
 Can be ordered through Booksellers. 
 
 FEN WICK'S Outlines of Practice of Medicine. With Formulae and Illustra- 
 tions. By SAMUEL FENWICK, M.D. i2mo. Cloth, $1.25 
 
 FIELD. Evacuant Medication Cathartics and Emetics. By HENRY M. FIELD, 
 M.D., Professor of Therapeutics, Dartmouth Medical College, Corporate Mem- 
 ber Gynaecological Society of Boston, etc. I2mo. 288 pp. Cloth, $1.75 
 
 FLAGG'S Plastics and Plastic Filling; As Pertaining to the Filling of all Cavities 
 of Decay in Teeth below Medium in Structure, and to Difficult and Inaccessible 
 Cavities in Teeth of all Grades of Structure. By J. FOSTER FLAGG, D.D.S., Pro- 
 fessor in the Philadelphia Dental College. Svo. Second Ed. Cloth, $4.00 
 
 FLOWER'S Diagrams of the Nerves of the Human Body. Exhibiting their 
 Origin, Divisions and Connections, with their Distribution to the various Regions 
 of the Cutaneous Surface, and to all the Muscles. By WILLIAM H. FLOWER, 
 F.R.C.S., F.R.S., Hunterian Professor of Comparative Anatomy, and Conservator 
 of the Museum of the Royal College of Surgeons. Third Edition, thoroughly 
 revised. With six Large Folio Maps or Diagrams. 410. Cloth, $3.50 
 
 FLUCKIGER. The Cinchona Barks Pharmacognostically Considered. By 
 Professor FRIEDRICH FLUCKIGER, of Strasburg. Translated by FREDERICK B. 
 POWER, PH.D., Professor of Materia Medica and Pharmacy, University of Wis- 
 consin. With 8 Lithographic Plates. Royal octavo. Cloth, $1.50 
 
 FOTHERGILL. On the Heart and Its Diseases. With Their Treatment. In- 
 cluding the Gouty Heart. By J. MILNER FOTHERGILL, M.D., Member of the 
 Royal College of Physicians of London. 2d Ed. Rewritten. Svo. Cloth, $3.50 
 
 FOX. Water, Air and Food. Sanitary Examinations of Water, Air and Food. 
 By CORNELIUS B. Fox, M.D. no Engravings. 2d Ed., Revised. Cloth, $4.00 
 
 FOX AND GOULD. Compend on Diseases of the Eye and Refraction, 
 including Treatment and Surgery. By L. WEBSTER Fox, M.D., Chief Clinical 
 Assistant, Ophthalmological Department, Jefferson Medical College Hospital ; 
 Ophthalmic Surgeon, Germantown Hospital, Philadelphia ; late Clinical Assistant 
 at Moorfields, London, England, etc., and GEO. M. GOULD, A.B. 60 Illustrations. 
 Being No. 8, ? Quiz- Compend ? Series. Cloth, $1.00 
 
 Interleaved for the addition of notes, $1.25 
 
 FRANKLAND'S Water Analysis. For Sanitary Purposes, with Hints for the In- 
 terpretation of Results. By E. FRANKLAND, M.D., F.R.S. Illustrated. i2mo. 
 
 Cloth, $1.00 
 
MEDICAL AND SCIENTIFIC PUBLICA TIONS. 11 
 
 GALABIN'S Midwifery. A Manual for Students and Practitioners. By A. LEWIS 
 GALABIN, M.D., F.R.C.P., Obstetric Physician to Guy's Hospital, London, and 
 Professor of Midwifery in the ame institution. 227 Illustrations. 
 
 Cloth, $3.00; Leather, $3.50 
 
 GAMGEE. Wounds and Fractures. The Treatment of Wounds and Fractures. 
 Clinical Lectures, by SAMPSON GAMGEE, F.R.S.E., Consulting Surgeon to Queen's 
 Hospital, Birmingham. 34 Engravings. Second Edition. 8vo. Cloth, $3.50 
 
 GARDNER'S TECHNOLOGICAL SERIES. The Brewer, Distiller and Wine 
 Manufacturer. A Handbook for all Interested in the Manufacture and Trade 
 of Alcohol and Its Compounds. Edited by JOHN GARDNER, F.C.S. Illustrated. 
 
 Cloth, $1.75 
 
 Bleaching, Dyeing, and Calico Printing. With Formulae. Illustrated. $1.75 
 Acetic Acid, Vinegar, Ammonia and Alum. Illustrated. Cloth, $1.75 
 
 Oils and Varnishes. Edited by JAMES CAMERON, F.I.C. Illustrated. $2.50 
 
 GIBBES'S Practical Histology and Pathology. By HENEAGE GIBBES, M.B. i2mo. 
 Third Edition. Cloth, $1.75 
 
 GILLIAM'S Pathology. The Essentials of Pathology; a Handbook for Students. 
 By D. TOD GILLIAM, M.D., Professor of Physiology, Starling Medical College, 
 Columbus, O. With 47 Illustrations. I2mo. Cloth, $2.00 
 
 GLISAN'S Modern Midwifery. A Text-book. By RODNEY GLISAN, M.D., Emeritus 
 Professor of Midwifery and Diseases of Women and Children in Willamette 
 Univ., Portland, Oregon. 129 Illus. 8vo. 2d Edition. Cloth, $3.00 
 
 GOODHART and STARR'S Diseases of Children. The Student's Guide to the 
 Diseases of Children. By J. F. GOODHART, M.D., F.R.C.P., Physician to Evelina 
 Hospital for Children, Demonstrator of Morbid Anatomy at Guy's Hospital. 
 Edited, with notes and additions, by Louis STARR, M.D., Clinical Professor of Dis- 
 eases of Children in the University of Pennsylvania. Cloth, $3.00; Leather, $3.50 
 
 GORGAS'S Dental Medicine. A Manual of Materia Medica and Therapeutics. 
 By FERDINAND J. S. GORGAS, M.D., D.D.S., Professor of the Principles of Dental 
 Science, Dental Surgery and Dental Mechanism in the Dental Department of 
 the University of Maryland. Second Edition. Enlarged. 8vo. Cloth, $3.25 
 
 GOWERS, Manual of Diseases of the Nervous System. A Complete Text-book. 
 By WILLIAM R. GOWERS, M.D., Ass't Prof. Clinical Medicine, University Col- 
 lege, London. Comprising over 300 Illustrations and 1000 pages. Octavo. 
 
 Nearly Ready. 
 
 Spinal Cord. Diagnosis of Diseases of the Spinal Cord. With Colored Plates 
 and Engravings. Fourth Edition. Enlarged. In Press. 
 
 Ophthalmoscopy. A Manual and Atlas of Ophthalmoscopy. With 16 
 Colored Autotype and Lithographic Plates and 26 Wood Cuts, comprising 
 112 Original Illustrations of the Changes in the Eye in Diseases of the 
 Brain, Kidneys, etc. 8vo. Cloth, $6.00 
 
 Diagnosis of Diseases of the Brain. 8vo. Second Edition. Illustrated. 
 
 Cloth, $2.00 
 
 Epilepsy and other Chronic Convulsive Diseases : Their Causes, Symptoms, 
 and Treatment. New Edition. 8vo. In Press. 
 
 r 
 
 GROSS'S Biography of John Hunter. John Hunter and His Pupils. By S. D 
 GROSS, M.D., Professor of Surgery in Jefferson Medical College, Philadelphia. 
 With a Portrait. 8vo. Paper, .75; Cloth, $1.25 
 
 GREENHOW. Chronic Bronchitis, especially as connected /vith Gout, Emphy- 
 sema, and Diseases of the Heart. By E. HEADLAM GREENHOW, M.D. i2mo. 
 
 Paper, .75; Cloth, $1.25 
 
12 P. BLAKISTON, SON 6- CO:S 
 
 GREENHOW. Addison's Disease. Illustrated by Plates and Reports of Cases. 
 By E. HEADLAM GREENHOW, M.D. 8vo. Cloth, $3.00 
 
 HABERSHON. On Some Diseases of the Liver. By S. O. HABERSHON, M.D., 
 F.R.C.P., late Senior Physician to Guy's Hospital. A New Edition. Cloth, $1.50 
 
 HADDON'S Embryology. An Introduction to the Study of Embryology. For 
 the Use of Students. By A. C. HADDON, M.A., Prof, of Zoology, Royal College 
 of Science, Dublin. 190 Illustrations. Cloth, 6.00 
 
 HALE. On the Management of Children in Health and Disease. A Book for 
 Mothers. By AMIE M. HALE, M.D. New Enlarged Edition. I2mo. Cloth, .75 
 
 HAEE. Tobacco, Its Physiological and Pathological Effects. 8vo. Illustrated. 
 The Fiske Fund Prize Dissertation for 1885. Paper Covers, .50 
 
 HARLAN. Eyesight and How to Care for It. By GEORGE C. HARLAN, M.D. 
 Prof, of Diseases of the Eye, Philadelphia Polyclinic. Illustrated. Cloth, .50 
 
 HARLEY. Diseases of the Liver, With or Without Jaundice. Diagnosis and 
 Treatment. By GEORGE HARLEY, M.D. With Colored Plates and Numerous 
 Illustrations. 8vo. Price reduced. Cloth, $3.00 ; Leather, $4.00 
 
 HARRIS'S Principles and Practice of Dentistry. Including Anatomy, Physi- 
 ology, Pathology, Therapeutics, Dental Surgery and Mechanism. By CHAPIN A. 
 HARRIS, M.D., D.D.S., late President of the Baltimore Dental College, author ol 
 "Dictionary of Medical Terminology and Dental Surgery." Eleventh Edition. 
 Revised and Edited by FERDINAND J. S. GORGAS, A.M., M.D., D.D.S., author of 
 "Dental Medicine;" Professor of the Principles of Dental Science, Dental 
 Surgery and Dental Mechanism in the University of Maryland. Two Full-page 
 Plates and 744 Illustrations. 994 pages. 8vo. Cloth, $6.50; Leather, $7.50 
 
 Medical and Dental Dictionary. A Dictionary of Medical Terminology, 
 Dental Surgery, and the Collateral Sciences. Fourth Edition, carefully 
 Revised and Enlarged. By FERDINAND J. S. GORGAS, M.D., D.D.S., Prof, of 
 Dental Surgery in the Baltimore College. 8vo. Cloth, $6.50 ; Leather, $7.50 
 
 HARTRIDGE. Refraction. The Refraction of the Eye. A Manual for Students. 
 By GUSTAVUS HARTRIDGE, F.R.C.S., Consulting Ophthalmic Surgeon to St. Bar- 
 tholomew's Hospital ; Ass't Surgeon to the Royal Westminster Ophthalmic Hos- 
 pital, etc. 94 Illustrations and Test Types. Third Edition. In Press. 
 
 HARTSHORNE. Our Homes. Their Situation, Construction, Drainage, etc. By 
 HENRY HARTSHORNE, M.D. Illustrated. Cloth, .50 
 
 HEADLAND'S Action of Medicines. On the Action of Medicines in the System. 
 By F. W. HEADLAND, M.D. Ninth American Edition. 8vo. Cloth, $3.00 
 
 HEATH'S Operative Surgery. A Course of Operative Surgery, consisting of a 
 Series of Plates, Drawn from Nature by M. Leveille, of Paris. With Descriptive 
 Text of Each Operation. By CHRISTOPHER HEATH, F.R.C.S., Holme Professor 
 of Clinical Surgery in University College, London. Quarto. Second Edition. 
 Revised. Sold by Subscription. Cloth, $12.00 
 
 Minor Surgery and Bandaging. Eighth Edition. Revised and Enlarged. 
 With 142 Illustrations. I2mo. Cloth, $2.00 
 
 Practical Anatomy. A Manual of Dissections. Sixth London Edition. 24 
 Colored Plates, and nearly 300 other Illustrations. Cloth, $5.00 
 
 Injuries and Diseases of the Jaws. Third Edition. Revised, with over 
 1 50 Illustrations. 8vo. Cloth, $4.50 
 
 HENRY. Anaemia. A Practical Treatise. By FRED'K P." HENRY, M.D., Prof. 
 Clinical Med. Phila. Polyclinic, Physician to Episcopal and Phila. Hospitals, to 
 Home for Consumptives, etc. i2mo. Half Cloth, .75 
 
 HIGGINS' Ophthalmic Practice. A Manual for Students and Practitioners. By 
 CHARLES HIGGINS, F.R.C.S. Ophthalmic Surgeon at Guy's Hospital. Practical 
 Series. Nearly Ready. 
 
 Ophthalmic Practice. A Handbook. Second Edition. 32mo. Cloth, .50 
 
MEDICAL AND SCIENTIFIC PUBLICA TIONS. 13 
 
 HILLIER. Diseases of Children. A Clinical Treatise. By THOMAS HILLIER, 
 
 M.D. 8vo. Paper, .75; Cloth, $1.25 
 
 HILL AND COOPER. Venereal Diseases. The Student's Manual of Venereal 
 
 Diseases, being a concise description of those Affections and their Treatment. 
 
 By BERKELEY HILL, M.U., Professor of Clinical Surgery, University College, and 
 
 ARTHUR COOPER, M.D., Late House Surgeon to the Lock Hospital. Londoh. 
 
 4th Edition. I2mo. Cloth, $1.00 
 
 HODGE'S Note-book for Cases of Ovarian Tumors. Paper, .50 
 
 HODGE on Foeticide or Criminal Abortion. By HUGH L. HODGE, M.D. Paper, .30 
 
 HOLDEN'S Anatomy. A Manual of the Dissections of the Human Body. By 
 LUTHER HOLDEN, F.R.C.S. Fifth Edition. Carefully Revised and Enlarged. 
 Specially concerning the Anatomy of the Nervous System, Organs of Special 
 Sense, etc. By JOHN LANGTON, F.R.C.S., Surgeon to, and Lecturer on Anatomy 
 at, St. Bartholomew's Hospital. 208 Illustrations. 8vo. 
 
 Oilcloth Covers, for the Dissecting Room, $4.50; Cloth, $5.00; Leather, $6.00 
 Human Osteology. Comprising a Description of the Bones, with Colored 
 Delineations of the Attachments of the Muscles. The General and Micro- 
 scopical Structure of Bone and its Development. Carefully Revised. By 
 the Author and Prof. STEWART, of the Royal College of Surgeons' Museum. 
 With Lithographic Plates and Numerous Illustrations. 7th Ed. Cloth, $6.00 
 
 HOLDEN. The Sphygmograph. Its Physiological and Pathological Indications. 
 By EDGAR HOLDEN, M.D. Illustrated. 8vo. Cloth, $2.00 
 
 HOLLAND. The Urine. Memoranda, Chemical and Microscopical, for Laboratory 
 Use. By J. W. HOLLAND, M.D., Professor of Medical Chemistry and Toxicology 
 in Jefferson Medical College, of Philadelphia. Illustrated. Cloth, .50 
 
 HOOD. Lectures to Nurses on the Symptoms of Disease. By DONALD HOOD, 
 M.D., M.R.C.P., Physician to the West London Hospital, etc. I2mo. Cloth, $1.00 
 
 HORWITZ'S Compend of Surgery, including Minor Surgery, Amputations, Frac- 
 tures, Dislocations, Surgical Diseases, and the Latest Antiseptic Rules, etc., with 
 Differential Diagnosis and Treatment. By ORVILLE HORWITZ, B.S., M.D., Dem- 
 onstrator of Anatomy, Jefferson Medical College ; Chief, Out-Patient Surgical 
 Department, Jefferson Medical College Hospital. Third Edition. Very much 
 Enlarged and Rearranged. 91 Illustrations and 77 Formulae. I2mo. A T o. g fQuiz- 
 Compend? Series. Cloth, $1.00. Interleaved for the addition of notes, $1.25 
 
 HTJFELAND. Long Life. Art of Prolonging Life. By C. W. HUFELAND. 
 Edited by ERASMUS WILSON, M.D. I2mo. Cloth, $1.00 
 
 HUGHES. Compend of the Practice of Medicine. Third Edition. Revised and 
 Enlarged. By DANIEL E. HUGHES, M.D., Demonstrator of Clinical Medicine at 
 Jefferson Medical College, Philadelphia. In two parts. Being Nos. 2 and j>, 
 ? Quiz- Compend ? Series. 
 
 PART I. Continued, Eruptive and Periodical Fevers, Diseases of the Stomach, 
 Intestines, Peritoneum, Biliary Passages, Liver, Kidneys, etc., and General 
 Diseases, etc. 
 
 PART II. Diseases of the Respiratory System, Circulatory System and Ner- 
 vous System ; Diseases of the Blood, etc. 
 
 Price of each Part, in Cloth, $1.00 ; interleaved for the addition of Notes, $1.25 
 Physicians' Edition. In one volume, including the above two parts, a sec- 
 tion on Skin Diseases, and an index. Revised Edition. 408 'pages. 
 
 Full Morocco, Gilt Edge, $2.50 
 
 JACOBSON. Operations of Surgery. By W. H. A. JACOBSON, B.A. OXON., 
 F.R.C.S., Eng. ; Ass't Surgeon, Guy's Hospital ; Surgeon at Royal Hospital for 
 Children and Women, etc. With over 200 Illustrations. In Press. 
 
 JAMES on Sore Throat. Its Nature, Varieties and Treatment, including its Con- 
 nection with other Diseases. By PROSSER JAMES, M.D. Fourth Edition, Re- 
 vised and Enlarged. Colored Plates and Wood-cuts. Paper .75 ; Cloth, $1.25 
 
14 P. BLAKISTON, SON &* CO.'S 
 
 JONES' Aural Surgery. A Practical Handbook on Aural Surgery. By H. 
 MACNAUGHTON JONES, M.D., Surgeon to the Cork Ophthalmic and Aural Hospital. 
 Illustrated. Second Edition, Revised and Enlarged, with new Wood Engravings. 
 I2mo. Cloth, $2.75 
 
 JOURNAL of Laryngology and Rhinology, A Monthly Analytical Record, 
 devoted to Diseases of the Throat and Nose. Edited by MORELL MACKENZIE, 
 M.D. Sample Nos., 25 cents. Subscription per annum, $3.00 
 
 KANE'S Drugs that Enslave. The Opium, Morphine, Chloral, and Similar 
 Habits. By H. H. KANE, M.D. With Illustrations. Cloth, $1.25 
 
 KERR. Inebriety. Its Etiology, Pathology, Treatment, etc., in its various forms. 
 By NORMAN S. KERR, M.D., Mem. of the Council of University of Glasgow. 
 
 In Press. 
 
 KIDD'S Laws of Therapeutics ; or, the Science and Art of Medicine. By JOSEPH 
 KIDD, M.D. I2mo. Paper, .75; Cloth, $1.25 
 
 KIRBY. Selected Remedies. A Pharmacopoeia of Selected Remedies, with 
 Therapeutic Annotations, Notes on Alimentation in Disease, Air, Massage, 
 Electricity and other Supplementary Remedial Agents, and a Clinical Index ; 
 arranged as a Handbook for Presenters. By E. A. KIRBY, M.D. Sixth Edition, 
 Enlarged and Revised. 4to. Cloth, $2.25 
 
 KIRKE'S Physiology. A Handbook of Physiology. By KIRKE. Eleventh Lon- 
 don Edition, Revised and Enlarged. By W. MORRANT BAKER, M.D. 460 Il- 
 lustrations. Cloth, $4.00; Leather, $5.00 
 
 LANDIS' Compend of Obstetrics ; especially adapted to the Use of Students and 
 Physicians. By HENRY G. LANDIS, M.D., Professor of Obstetrics and Diseases 
 of Women, in Starling Medical College, Columbus, Ohio. Third Edition. 
 Revised. With New Illustrations. No. 5 ? Quiz- Compend? Series. 
 
 Cloth, $1.00; interleaved for the addition of Notes, $1.25 
 
 LANDOIS. A Text-Book of Human Physiology ; including Histology and Micro- 
 scopical Anatomy, with special reference to the requirements of Practical Medi- 
 cine. By DR. L. LANDOIS, Professor of Physiology and Director of the Physio- 
 logical Institute in the University of Greifswald. Second American, translated 
 from the Fifth German Edition, with additions, by WM. STIRLING, M.D., D.SC., 
 Professor of the Institutes of Medicine in the University of Aberdeen. With 
 583 Illustrations. 8vo. I Volume. Cloth, $6.50; Leather, $7.50 
 
 LEBER AND ROTTENSTEIN. Dental Caries and Its Causes. An Investigation 
 into the Influence of Fungi in the Destruction of the Teeth. By Drs. LEBER 
 and ROTTENSTEIN. Illustrated. Paper, .75 ; Cloth, #1.25 
 
 LEE. The Microtomist's Vade Mecum. By ARTHUR BOLLES LEE. A Handbook 
 of the Methods of Microscopical Anatomy. 660 Formulae, etc. Cloth, $3.00 
 
 LEFFMANN'S Organic and Medical Chemistry. Including Urine Analysis and 
 the Analysis of Water and Food. By HENRY LEFFMANN, M.D., Demonstrator 
 of Chemistry at Jefferson Medical College, Philadelphia. No. 10 ? Quiz- Compend? 
 Series. I2mo. Cloth, $1.00. Interleaved for the addition of Notes, $1.25 
 
 LEGG OH the Urine. Practical Guide to the Examination of the Urine, for 
 Practitioner and Student. By J. WICKHAM LEGG, M.D. Sixth Edition, Enlarged. 
 Illustrated. I2mo. Cloth, .75 
 
 LEWIN on Syphilis. The Treatment of Syphilis. By Dr. GEORGE LEWIN, of 
 Berlin. Translated by CARL PROEGLER, M.D., and E. H. GALE, M.D., Surgeons 
 U. S. Army. Illustrated. I2mo. Paper, .75 ; Cloth, $1.25 
 
 LIEBREICH'S Atlas of Ophthalmoscopy, composed of 12 Chromo-Lithographic 
 Plates (containing 59 Figures), with Text. Translated by H. R. SWANZY, M.D. 
 Third Edition. 410. Boards, $15.00 
 
 LINCOLN. School and Industrial Hygiene. By D. F. LINCOLN, M.D. Cloth, .50 
 
MEDICAL AND SCIENTIFIC PUBLICA TIONS. 15 
 
 LONGLEY'S Pocket Medical Dictionary for Students and Physicians. Giving 
 the Correct Definition and Pronunciation of all Words and Terms in General 
 Use in Medicine and the Collateral Sciences, with an Appendix, containing 
 Poisons and their Antidotes, Abbreviations Used in Prescriptions, and a Metric 
 Scale of Doses. By ELIAS LONGLEY. Cloth, 1.00; Tucks and Pocket, $1.25 
 
 LIZARS. On Tobacco. The Use and Abuse of Tobacco. By JOHN LIZARS, M.D. 
 121110. Cloth, .50 
 
 Ltf CKES. Hospital Sisters and their Duties. By EVA C. E. LUCRES, Matron to 
 the London Hospital; Author of " Lectures on Nursing." I2mo. Cloth. $1.00 
 
 MAC MUNN. On the Spectroscope in Medicine. By CHAS. A. MAC Muxx, M.D. 
 With 3 Chromo-lithographic Plates of Physiological and Pathological Spectra, 
 and 13 Wood Cuts. 8vo. Cloth, $3.00 
 
 MACNAMARA. On the Eye. A Manual of the Diseases of the Eye. By C. 
 MACNAMARA, M.D. Fourth Edition, Carefully Revised; with Additions and 
 Numerous Colored Plates, Diagrams of Eye, Wood-cuts, and Test Types. 
 Demi Svo. Cloth, $4.00 
 
 MACDONALD'S Microscopical Examinations of Water and Air. A Guide to the 
 Microscopical Examination of Drinking Water, with an Appendix on the Micro- 
 scopical Examination of Air. By J. D. MACDONALD, M.D. With 25 Litho- 
 graphic Plates, Reference Tables, etc. Second Ed., Revised. Svo. Cloth, $2.75 
 
 MACKENZIE on the Throat and Nose. Complete in one octavo vol. Including 
 the Pharynx, Larynx, Trachea, (Esophagus, Nasal Cavities, etc., etc. By 
 MORELL MACKENZIE, M.D., Senior Physician to the Hospital for Diseases of 
 the Chest and Throat, Lecturer on Diseases of the Throat at London Hospital 
 Medical College, etc. Revised and Edited by D. BRYSON DELAVAN, M.D., Prof, 
 of Laryngology and Rhinology in the New York Polyclinic ; Chief of Clinic, 
 Department of Diseases of the Throat, Col. of Physicians and Surgeons, New 
 York; Sec. of the American Laryngological Association, etc. One vol. Octavo. 
 About 800 pages. Full list of Useful Formulas, and over 200 Illustrations. 
 
 Nearly Ready. 
 
 The (Esophagus, Nose, Naso-Pharynx, etc. Illustrated. Being Vol. II of 
 the First Edition of Dr. MACKENZIE'S Treatise. Complete in itself 
 
 Cloth, $3.00 ; Leather, $4.00 
 
 The Pharmacopoeia of the Hospital for Diseases of the Throat and Nose. 
 Fourth Edition, Enlarged, Containing 250 Formulae, with Directions for their 
 Preparation and Use. i6mo. Cloth, $1.25 
 
 Growths in the Larynx. Their History, Causes, Symptoms, etc. With 
 Reports and Analysis of one Hundred Cases. With Colored and other 
 Illustrations. Svo. Paper, .75 ; Cloth, $ 1.2 5 
 
 MADDEN. Health Resorts for the Treatment of Chronic Diseases. The result 
 of the author's own observations during several years of health travel in many 
 lands. With remarks on climatology and the use of mineral waters. By T. M. 
 MADDEN, M.D. Svo. . Cloth, $2.50 
 
 MANN'S Manual of Psychological Medicine and Allied Nervous Diseases. Their 
 Diagnosis, Pathology, Prognosis and Treatment, including their Medico-Legal 
 Aspects ; with chapter on Expert Testimony, and an abstract of the laws relating 
 to the Insane in all the States of the Union. By EDWARD C. MANN, M.D., 
 member of the New York County Medical Society. With Illustrations of Typical 
 Faces of the Insane, Handwriting of the Insane, and Micro-photographic Sec- 
 tions of the Brain and Spinal Cord. Octavo. Cloth, $5.00 ; Leather $6.00 
 
 MARSHALL & SMITH. On the Urine. The Chemical Analysis of the Urine. 
 By JOHN MARSHALL, M.D., and Prof. EDGAR F. SMITH, of the Chemical Labora- 
 tories, University of Pennsylvania. Phototype Plates. I2mo. Cloth, $1.00 
 
 MARTIN'S Microscopic Mounting. A Manual. With Notes on the Collection 
 and Examination of Objects. 150 Illustrations. By JOHN H. MARTIN. Second 
 Edition, Enlarged. Svo. Cloth, $2.75 
 
16 P. BLAKISTON, SON <S- CO.'S 
 
 MARSHALL. Anatomical Plates ; or Physiological Diagrams. Life Size (4 by 
 7 feet.) Beautifully Colored. By JOHN MARSHALL, F.R.S. New Edition. Re- 
 vised and Improved, Illustrating the Whole Human Body. 
 
 The Set, 11 Maps, in Sheets, $50.00 
 
 The Set, 1 1 Maps, on Canvas, with Rollers, and Varnished, 80.00 
 
 An Explanatory Key to the Diagrams, .50 
 
 No. i. The Skeleton and Ligaments. No. 2. The Muscles, Joints, and Animal Mechanics. No. 3. 
 The Viscera in Position The Structure of the Lungs. No. 4. The Organs of Circulation. No. 5. 
 The Lymphatics or Absorbents. No. 6. The Digestive Organs. No. 7. The Brain and Nerves. 
 No. 8. The Organs of the Senses and Organs of the Voice, Plate i. No. 9. The Organs of the Senses, 
 Plate 2. No. 10. The Microscopic Structure of the Textures. No. n. The Microscopic Structure 
 of the Textures. 
 
 MASON'S Compend of Electricity, and its Medical and Surgical Uses. By 
 CHARLES F. MASON, M.D., Assistant Surgeon U. S. Army. With an Intro- 
 duction by CHARLES H. MAY, M.D., Instructor in the New York Polyclinic. 
 Numerous Illustrations. I2mo. Being Medical Briefs, No. 3. Cloth, $1.00 
 
 MAYS' Therapeutic Forces ; or, The Action of Medicine in the Light of the Doc- 
 trine of Conservation of Force. By THOMAS J. MAYS, M.D. Cloth, $1.25 
 
 MEADOWS' Obstetrics. A Text-Book of Midwifery. Including the Signs and 
 Symptoms of Pregnancy, Obstetric Operations, Diseases of the Puerperal State, 
 etc. By ALFRED MEADOWS, M.D. Third American, from Fourth London Edi- 
 tion. Revised and Enlarged. With 145 Illustrations. 8vo. Cloth, $2.00 
 
 MEDICAL Directory of Philadelphia, Pennsylvania, Delaware and Southern half 
 of New Jersey, containing lists of Physicians of all Schools of Practice, Dentists, 
 Druggists and Chemists, with information concerning Medical Societies, Colleges 
 and Associations, Hospitals, Asylums, Charities, etc. Morocco, Gilt edges, $2.50 
 
 MEIGS. Milk Analysis and Infant Feeding. A Practical Treatise on the Ex- 
 amination of Human and Cows' Milk, Cream, Condensed Milk, etc., and 
 Directions as to the Diet of Young Infants. By ARTHUR V. MEIGS, M.D., Physi- 
 cian to the Pennsylvania Hospital, Philadelphia. i2mo. Cloth, $1.00 
 
 MEIGS and PEPPER on Children. A Practical Treatise on the Diseases of 
 Children. By J. FORSYTH MEIGS, M.D., Fellow of the College of Physicians of 
 Philadelphia, etc., etc., and WILLIAM PEPPER, M.D., Professor of the Principles 
 and Practice of Medicine in the Medical Department, University of Pennsyl- 
 vania. Seventh Edition. Cloth, $5.00; Leather, $6.00 
 
 MERRELL'S Digest of Materia Medica. Forming a Complete Pharmacopoeia for 
 the use of Physicians, Pharmacists and Students. By ALBERT MERRELL, M.D. 
 Octavo. Half dark Calf, $4.00 
 
 MEYER. Ophthalmology. A Manual of Diseases of the Eye. By DR. EDOUARD 
 MEYER, Prof, a L'cole de la Faculte de Medicine de Paris, Chev. of the Legion 
 of Honor, etc. Translated from the Third French Edition, with the assistance 
 of the author, by A. FREEDLAND FERGUS, M.B., Assistant Surgeon Glasgow 
 Eye Infirmary. With 270 Illustrations, and two Colored Plates. Prepared 
 under the direction of DR. RICHARD LIEBREICH, M.R.C s., Author of the "Atlas 
 of Ophthalmoscopy." 8vo. Cloth, $4.50 ; Leather, $5.50 
 
 MILLER and LIZAR'S Alcohol and Tobacco. Alcohol. Its Place and Power. 
 By JAMES MILLER, F.R.C.S. ; and, Tobacco, Its Use and Abuse. By JOHN LIZARS, 
 M.D. The two essays in one volume. Cloth, $1.00; Separate, each .50 
 
 MONEY. On Children. Treatment of Disease in Children, including the Outlines 
 of Diagnosis and the Chief Pathological Differences between Children and 
 Adults. By ANGEL MONEY, M.D., M.R.C.P., Asst. Physician to the Hospital for 
 Sick Children, Great Ormond St., and to the Victoria Park Chest Hospital, Lon- 
 don. Practical Series. I2mo. 560 pages. Cloth, $3.00 
 
 MORRIS. Compend of Gynaecology. By HENRY MORRIS, M.D., Demonstrator of 
 Obstetrics, Jefferson Medical College, Phila., etc. Being ? Quiz- Compend? 
 No. 7. Nearly Ready. 
 
 MORTON on Refraction of the Eye. Its Diagnosis and the Correction of its Errors. 
 With Chapter on Keratoscopy, and Test Types. By A. MORTON, M.B. Third 
 Edition, Revised and Enlarged. Cloth, $1.00 
 
MEDICAL AND SCIENTIFIC PVBLICA TIONS. 17 
 
 MTJRRELL. Massage as a Mode of Treatment. By WM. MURRELL, M.D., 
 M.R.C.P., Lecturer on Materia Medica and Therapeutics at Westminster Hospital, 
 Examiner at University of Edinburgh, Physician to Royal Hospital for Diseases 
 of the Chest. Third Edition. I2mo. Cloth, $1.50 
 
 MUTER. Practical and Analytical Chemistry. By JOHN MUTER, F.R.S., F.C.S., 
 
 etc. Third Edition. Revised and Illustrated. Cloth, $2.00 
 
 OSGOOD. The Winter and Its Dangers. By HAMILTON OSGOOD, M.D. Cloth, .50 
 
 OTT'S Action of Medicines. By ISAAC OTT, M.D., late Demonstrator of Experi- 
 mental Physiology in the University of Pennsylvania. 22 Illus. Cloth, $2.00 
 
 OVERMAN'S Practical Mineralogy, Assaying and Mining, with a Description of 
 the Useful Minerals, etc. By FREDERICK OVERMAN, Mining Engineer. Elev- 
 enth Edition. i2mo. Cloth, $ i. co 
 
 OPHTHALMIC REVIEW. A Monthly Record of Ophthalmic Science. Published 
 in London. Sample Xicnibers, 25 cents. Per annum, $3.00 
 
 PACKARD'S Sea Air and Sea Bathing. By JOHN H. PACKARD, one of the Phy- 
 sicians to the Pennsylvania Hospital, Philadelphia. Cloth, .50 
 
 PAGE'S Injuries of the Spine and Spinal Cord, without apparent Lesion and Ner- 
 vous Shock. In their Surgical and Medico-Legal Aspects. By HERBERT W. 
 PAGE, M.D., F.R.C.S. Second Edition, Revised. Octavo. Cloth, $3.50 
 
 PAGET'S Lectures on Surgical Pathology. Delivered at the Royal College of 
 Surgeons. By JAMES PAGET, F.R.S. Third Edition. Cloth, $7.00 ; Leather, $8.00 
 
 PARKES' Practical Hygiene. By EDWARD A. PARKES, M.D. The Seventh Re- 
 vised and Enlarged Edition. With Many Illustrations. 8vo. Cloth, $4.50 
 
 PARRISH'S Alcoholic Inebriety. From a Medical Standpoint, with Illustrative 
 Cases from the Clinical Records of the Author. By JOSEPH PARRISH, M.D., 
 President of the Amer. Assoc. for Cure of Inebriates. Paper, .75 ; Cloth, $1.25 
 
 PARVIN'S Winckel's Diseases of Women (see Winckel-Parvin, page 24). 
 
 117 Illustrations. Cloth, $3.00; Leather, 3.50 
 
 PENNSYLVANIA Hospital Reports. Edited by a Committee of the Hospital 
 Staff: J. M. DACOSTA, M.D., and WILLIAM HUNT. Containing Original Articles 
 by the Staff. With many other Illustrations. Paper, .75 ; Cloth, $1.25 
 
 PHYSICIAN'S VISITING LIST. Published Annually. Thirty-seventh Year of its 
 Publication. 
 
 SIZES AND PRICES. 
 
 For 25 Patients weekly. Tucks, pocket and pencil, Gilt Edges, . . $1.00 
 
 50 . 1.25 
 
 75 " " " " " . . 1.50 
 
 100 . . 2.00 
 
 Jan. to June 
 
 100 
 
 2 vols ' \ July to Dec. 
 
 Jan. to 
 July to 
 
 June 
 Dec. 
 
 3.00 
 
 INTERLEAVED EDITION. 
 
 For 25 Patients weekly, interleaved, tucks, pocket, etc., " . .. 1.25 
 
 50 " . 1.50 
 
 Perpetual Edition, without Dates and with Special Memorandum Pages. 
 
 For 25 Patients, interleaved, tucks, pocket and pencil, .... $1.25 
 
 50 " " " " .... 1.50 
 
 EXTRA Pencils will be sent, postpaid, for 25 cents per half dozen. 
 Bjg D> This List combines the several essential qualities of strength, compactness, durability 
 and convenience. A special circular, descriptive of contents and improvements, will be sent 
 upon application.. 
 
18 P. BLAKISTON, SON 6- CO.'S 
 
 PEREIRA'S Prescription Book. Containing Lists of Terms, Phrases, Contrac- 
 tions and Abbreviations used in Prescriptions, Explanatory Notes, Grammatical 
 Construction of Prescriptions, Rules for the Pronunciation of Pharmaceutical 
 Terms. By JONATHAN PEREIRA, M.D. Sixteenth Edition. 
 
 Cloth, $1.00 ; Leather, with tucks and pocket, $1.25 
 
 PHILLIPS' Materia Medica and Therapeutics. Vegetable Kingdom. Organic 
 Compounds. Animal Kingdom. By CHAS. D. F. PHILLIPS, M.D., F.R.S., Edin., 
 late Lecturer on Materia Medica and Therapeutics, Westminster Hospital, Lon- 
 don. Second Edition (Complete). Enlarged and.Revised. Cloth, $7.50 
 
 PIESSE'S Art of Perfumery, or the Methods of Obtaining the Odors of Plants, and 
 Instruction for the Manufacture of Perfumery, Dentrifices, Soap, Scented Pow- 
 ders, Cosmetics, etc. By G. W. SEPTIMUS PIESSE. Fourth Edition. 366 Illus- 
 trations. Cloth, $5.50 
 
 PIGGOTT on Copper Mining and Copper Ore. With a full Description of the 
 Principal Copper Mines of the United States, the Art of Mining, etc. By A. 
 SNOWDEN PIGGOTT. i2mo. Cloth, $1.00 
 
 PORTER'S Surgeon's Pocket-Book. By SURGEON-MAJOR J. H. PORTER, late Pro- 
 fessor of Military Surgery in the Army Medical School, Netley , England. Revised, 
 and partly Re-written, by SURGEON-MAJOR C. H. GODWIN, of the Army Medical 
 School (Netley, England). Third Edition. Small I2mo. Leather Covers, $2.25 
 
 POLYCLINIC, The. A Monthly Journal of Medicine and Surgery. Edited by 
 HENRY LEFFMANN, M.D. 32 pages, monthly. Now in its 5th Volume. Royal 
 8vo. Sample Numbers free. Per annum, $1.00. 
 
 POWER, HOLMES, ANSTIE and BARNES (Drs.) Reports on the Progress of 
 Medicine, Surgery, Physiology, Midwifery, Diseases of Women and Children, 
 Materia Medica, Medical Jurisprudence, Ophthalmology, etc. Reported for the 
 New Syndenham Society. 8vo. Paper, .75 ; Cloth, #1.25 
 
 POTTER, A Handbook of Materia Medica, Pharmacy and Therapeutics, in- 
 cluding the Action of Medicines, Special Therapeutics, Pharmacology, etc. In- 
 cluding over 600 Prescriptions and Formulae. By SAMUEL O. L. POTTER, M.A., 
 M.D., Professor of the Practice of Medicine, Cooper Medical College, San Fran- 
 cisco ; late A. A. Surgeon U. S. Army. Cloth, $3.00; Leather, $3.50 
 Speech and Its Defects. Considered Physiologically, Pathologically and 
 Remedially ; being the Lea Prize Thesis of Jefferson Medical College, 1882. 
 Revised and Corrected. I2mo. Cloth, $1.00 
 Compend of Anatomy, including Visceral Anatomy, formerly published 
 separately. Fourth Edition, Revised, and greatly Enlarged. With an Index 
 and 117 Illustrations. Being No. I ? Quiz- Compend ? Series. Cloth, $1.00 
 
 Interleaved for taking Notes, $1.25 
 
 Compend of Materia Medica, Therapeutics and Prescription Writing, 
 arranged in accordance with the last Revision U. S. Pharmacopoeia, with 
 special reference to the Physiological Action of Drugs. Fourth Revised 
 Edition, with Index. Being No. 6 ? Quiz- Compend? Series. Cloth, $1.00 
 
 Interleaved for taking Notes, $1.25 
 
 PRINCE'S Plastic and Orthopaedic Surgery. By DAVID PRINCE, M.D. Contain- 
 ing a Report on the Condition of, and Advance made in, Plastic and Orthopaedic 
 Surgery, etc. Numerous Illustrations. 8vo. Cloth, $4.50 
 
 PRITCHARD on the Ear. Handbook of Diseases of the Ear. By URBAN 
 PRITCHARD, M.D., F.R.C.S., Professor of Aural Surgery, King's College, London, 
 Aural Surgeon to King's College Hospital, Senior Surgeon to the Royal Ear 
 Hospital, etc. I2mo. Being Vol. 4, in the Practical Series. Cloth, $1.50 
 
 PROCTER'S Practical Pharmacy. Lectures on Practical Pharmacy. With 43 
 Engravings and 32 Lithographic Fac -simile Prescriptions. By BARNARD S. 
 PROCTER. Second Edition. Cloth, $4.50 
 
 PYE. Surgical Handicraft. A Manual of Surgical Manipulatipns, Minor Sur- 
 gery and other Matters connected with the work of Surgeons, Surgeons' Assist- 
 ants, etc. By WALTER PYE, M.D., Surgeon to St. Mary's Hospital, London. 
 208 Illustrations. Cloth, $5.00 
 
MEDICAL AND SCIENTIFIC PUBLIC A TIONS. 19 
 
 RADCLIFFE on Epilepsy, Pain, Paralysis, and other Disorders of the Nervous 
 System. By CHARLES BLAND RADCLIFFE, M.D. Illus. Paper, .75 ; Cloth, $1.25 
 
 RALFE. Diseases of the Kidney and Urinary Derangements. By C. H. RALFE, 
 M.D., F.R.C.P., Ass't Physician to the London Hospital. Illustrated. I2mo. 
 Volume j, Practical Series. Cloth, $2.75 
 
 RANDALL & MORSE. Anatomy of the Ear, Photographic Illustrations of the 
 Anatomy of the Human Ear, together with Pathological Conditions of the Drum 
 Membrane, and Descriptive Text. By B. ALEX. RANDALL, A.M., M.D., and 
 HENRY LEE MORSE, B.A., M.D. 25 Plates, comprising 75 Figures. Quarto. 
 
 In Portfolio, net, 5.00 
 
 REESE'S Medical Jurisprudence and Toxicology. A Text-book for Medical and 
 Legal Practitioners and Students. By JOHN J. REESE, M.D., Editor of Taylor's 
 Jurisprudence, Professor of the Principles and Practice of Medical Jurisprudence, 
 including Toxicology, in the University of Pennsylvania Medical and Law 
 Schools. Crown Octavo. Cloth, $3.00 ; Leather, $3.50 
 
 REEVES. Bodily Deformities and their Treatment. A Handbook of Practical 
 Orthopaedics. By H. A. REEVES, M.D., Senior Ass't Surgeon to the London 
 Hospital, Surgeon to the Royal Orthopaedic Hospital. 228 Illus. Cloth, $2.25 
 
 REYNOLDS. Electricity. Lectures on the Clinical Uses of Electricity. By J. 
 RUSSELL REYNOLDS, M.D., F.R.S. Second Edition. I2mo. Cloth, $1.00 
 
 RICHARDSON. Long Life, and How to Reach It. By J. G. RICHARDSON, Prof. 
 of Hygiene, University of Penna. Cloth, .50 
 
 RICHARDSON'S Mechanical Dentistry. A Practical Treatise on Mechanical 
 Dentistry. By JOSEPH RICHARDSON, D.D.S. Fourth Edition. Revised and 
 Enlarged. With 458 Illustrations. 710 pages. 8vo. Cloth, $4.50; Leather, $5.50 
 
 RIGBY'S Obstetric Memoranda. 4th Ed. By ALFRED MEADOWS, M.D. 321110. 
 
 Cloth, .50 
 
 RINDFLEISCH'S General Pathology. A Handbook for Students and Physicians. 
 By Prof. EDWARD RINDFLEISCH, of Wurzburg. Translated by WM. H. MERCUR, 
 M.D., of Pittsburgh, Pa., Edited and Revised by JAMES TYSON, M.D., Professor of 
 Morbid Anatomy and Pathology, University of Pennsylvania. Cloth, $2.00 
 
 RICHTER'S Inorganic Chemistry. A Text-book for Students. By Prof. VICTOR 
 
 VON RICHTER, University of Breslau. Third American, from Fifth German 
 
 Edition. Authorized Translation by EDGAR -F. SMITH, M.A., PH.D., Prof, of 
 
 Chemistry, Wittenberg College, formerly in the Laboratories of the University 
 
 of Pennsylvania, Member of the Chemical Societies of Berlin and Paris. With 
 
 89 Illustrations and a Colored Plate of Spectra. I2mo. Cloth, $2.00 
 
 Organic Chemistry. A Text-book for Students. Translated from the Fourth 
 
 German Ed., by Prof. Edgar F. Smith. Illus. Cloth, $3.00 ; Leather, $3.50 
 
 ROBERTS. Club-Foot. Clinical Lectures on Orthopaedic Surgery, Nos. I and II. 
 The Etiology, Morbid Anatomy, Varieties and Treatment of Club-Foot. By 
 A. SYDNEY ROBERTS, M.D., Instructor in Orthopaedic Surgery in the University 
 of Pennsylvania, Surg. to the Univ. Hospital. Illustrated. I2mo. Cloth, .50 
 
 ROBERTS. Practice of Medicine. The Theory and Practice of Medicine. By 
 
 FREDERICK ROBERTS, M.D., Professor of Therapeutics at University College, 
 
 London. Sixth Edition, thoroughly revised and enlarged, with Illustrations. 
 
 Svo. Cloth, $5.00; Leather, $6.00 
 
 Materia Medica and Pharmacy. A Compend for Students. Cloth, 32.00 
 
 ROBERTS. Surgical Delusions and Follies. By JOHN B. ROBERTS, M.D., Professor 
 
 of Anatomy and Surgery, in the Philadelphia Polyclinic. Paper, .25 ; Cloth, .50 
 
 The Human Brain. The Field and Limitation of the Operative Surgery of 
 
 the Human Brain. Illustrated. Svo. Cloth, $1.25 
 
 SANDERSON'S Physiological Laboratory. A Handbook of the Physiological 
 
 Laboratory. Being Practical Exercises for Students in Physiology and Histology. 
 
 By J. BURDON SANDERSON, M.D., E. KLEIN, M.D., MICHAEL FOSTER, M.D., F.R.S., 
 
 and T. LAUDER BRUNTON, M.D. With over 350 Illustrations and Appropriate 
 
 Letter-press Explanations and References. One Volume. Cloth, $5.00 
 
20 P. BLAKISTON, SON 6- CO.'S 
 
 SANSOM'S Diseases of the Heart. Valvular Disease of the Heart. By ARTHUR 
 
 ERNEST SANSOM, M.D. Illustrated. I2mo. Cloth, $1.25 
 
 On Chloroform. Its Action and Administration. Paper, .75 ; Cloth, $1.25 
 
 SAVAGE. Atlas of the Female Pelvic Organs. The Surgery, Surgical Pathology 
 and Surgical Anatomy of the Female Pelvic Organs. In a series of Plates 
 taken from nature, with Commentaries, Notes and Cases. By HENRY SAVAGE, 
 M.D., Lond., F.R.C.S. Fifth Edition. Revised and greatly extended. 17 Col- 
 ored Plates, comprising many Figures. Quarto. Cloth, net, 12.00 
 
 SCANZONT, Sexual Organs of Women. A Practical Treatise on the Diseases 
 of the Sexual Organs of Women. By F. W. VON SCANZONI, Prof, of Midwifery 
 and Diseases of Females, University of Wiirzburg, etc. Edited by A. K. GARD- 
 NER, A.M., M.D. 60 Illustrations. Fourth Edition. Octavo. Cloth, $4.00 
 
 SCHTJLTZE'S Obstetrical Plates. Obstetrical Diagrams. Life Size. By Prof. B. 
 
 S. SCHULTZE, M.D., of Berlin. Twenty in the Set. Colored. 
 
 In Sheets, $15.00; Mounted on Rollers, $25.00 
 SOLLY'S Colorado Springs and Manitou as Health Resorts. By S. EDWIN SOLLY, 
 
 M.D., M.R.C.S., Eng. I2mo. Paper cover, .25 
 
 SMITH'S Wasting Diseases of Infants and Children. By EUSTACE SMITH, M.D., 
 F.R.C.P., Physician to the East London Children's Hospital. Fourth London 
 Edition, Enlarged. 8vo. Cloth, $3.00 
 
 Clinical Studies of Diseases in Children. Second Edition, Revised. Svo. 
 Just Ready. Cloth, $2.50 
 
 SMITH. Abdominal Surgery. Being a Systematic Description of all the Princi- 
 pal Operations. By J. GREIG SMITH, M.A., F.R.S.E., Surg. to British Royal In- 
 firmary, Fellow Royal Med. Chir. Soc., etc. With 45 Engravings. Svo. 
 
 New Edition, Enlarged. In Press. 
 
 SMYTHE'S Medical Heresies. Historically Considered. A Series of Critical Es- 
 says on the Origin and Evolution of Sectarian Medicine, embracing a Special 
 Sketch and Review of Homceopathy, Past and Present. By GONZALVO C. 
 SMYTHE, A.M., M.D., Professor of the Principles and Practice of Medicine, Col- 
 lege of Physicians and Surgeons, Indianapolis, Indiana. I2rno. Cloth, $1.25 
 
 SMITH (TYLER). Lectures on Obstetrics. Delivered at St. Mary's Hospital. 
 With an Introductory Lecture on the History and Art of Midwifery, and Copious 
 Annotations. By A. K. GARDNER, A.M., M.D. 233 Illus. 3d Ed. Svo. Cloth, $4.00 
 
 STAMMER. Chemical Problems, with Explanations and Answers. By KARL 
 STAMMER. Translated from the 2d German Edition, by Prof. W. S. HOSKINSON, 
 A.M., Wittenberg College, Springfield, Ohio. I2mo. Cloth. .75 
 
 STARR. The Digestive Organs in Childhood. The Diseases of the Digestive 
 Organs in Infancy and Childhood. With Chapters on the Investigation of 
 Disease and the Management of Children. By Louis STARR, M.D., Clinical 
 Prof, of Diseases of Children in the Hospital of the University of Penn'a ; Physi- 
 cian to the Children's Hospital, Phila. Svo. Cut or uncut edges. Cloth, $2.50 
 
 STARR and WALKER. Physiological Action of Medicines. Prepared for the 
 use of Students of the Medical Department, University of Penna., with the 
 approval of the Professor of Materia Medica (H. C. WOOD, M.D). By Louis 
 STARR, M.D., Clin. Prof. Dis. of Children, in the Hospital of the University, and 
 J. B.WALKER, M.D., Prof, of Med., Woman's Med'l. College of Phila.; assisted 
 by W. M. POWELL, M.D., Physician to Children's Clinic, University Hospital. 
 Third Edition. Enlarged. 321110. Cloth, .75 
 
 STEWART'S Compend of Pharmacy. Based upon " Remington's Text-Book of 
 Pharmacy." By F. E. STEWART, M.D., PH.G., Quiz Master in Chem. and Theoreti- 
 cal Pharmacy, Phila. College of Pharmacy ; Demonstrator and Lect. in Pharma- 
 cology, Medico-Chirurgical College, and in Woman's Medical College. 2d. Ed. 
 ? Quiz- Compend? Series. Cloth, $1.00 ; Interleaved for the addition of notes, $1.25 
 
 STOCKEN'S Dental Materia Medica. Dental Materia Medica and Therapeutics 
 with Pharmacopoeia. By JAMES STOCKEN, D.D.S. Third Edition. Cloth, $2.50 
 
MEDICAL A AD SCIENTIFIC PUBLICATIONS. 21 
 
 BUTTON'S Volumetric Analysis. A Systematic Handbook for the Quantitative 
 Estimation of Chemical Substances by Measure, Applied to Liquids, Solids and 
 Gases. By FRANCIS SUTTON, F.C.S. Fifth Edition, Revised and Enlarged, 
 with Illustrations. 8vo. Cloth, $4.50 
 
 SUTTON. Pathology. An Introduction to General Pathology, founded on three 
 lectures delivered at the Royal College of Surgeons of England, 1886. By 
 JOHN BLAND SUTTON, F.R.C.S., Lecturer on Pathology, Royal College of Sur- 
 geons ; Assistant Surgeon and Demonstrator of Anatomy, Middlesex Hospital, 
 London. 149 Illustrations. Cloth, $4.50 
 
 Ligaments. Their Nature and Morphology. Illustrated. I2mo. Cloth, 1.25 
 
 SWAIN. Surgical Emergencies, together with the Emergencies Attendant on 
 Parturition and the Treatment of Poisoning. A Manual for the Use of General 
 Practitioners. By W. F. SWAIN, F.R.c.S. Fourth Edition. Illustrated. 1.50 
 
 SWAYNE'S Obstetric Aphorisms, for the Use of Students commencing Midwifery 
 Practice. By JOSEPH G. SWA YNE, M.D. Eighth Edition. Illus. Cloth, $1.25 
 
 TAFT'S Operative Dentistry. A Practical Treatise on Operative Dentistry. By 
 JONATHAN TAFT, D.D.S. Fourth Revised and Enlarged Edition. Over 100 Il- 
 lustrations. 8vo. Cloth, ^4.25 ; Leather, $5.00 
 Index of Dental Periodical Literature 8vo. Cloth, $2.00 
 
 TALBOT. Irregularities of the Teeth, and Their Treatment. By EUGENE S. 
 TALBOT, M.D., Professor of Dental Surgery Woman's Medical College, and 
 Lecturer on Dental Pathology in Rush Medical College, Chicago. Octavo. 150 
 Illustrations. Cloth, $2.00 
 
 TANNER'S Index of Diseases and their Treatment. By THOS. HAWKES TANNER, 
 M.D., F.R.C.P. Second Edition, Revised and Enlarged. By W. H. BROADBENT, 
 M.D. With Additions. Appendix of Formulas, etc. 8vo. Cloth, $3.00 
 
 Memoranda of Poisons and their Antidotes and Tests. Fifth American, from 
 the Last London Edition. Revised by HENRY LEFFMANN, M.D., Professor 
 of Chemistry in Pennsylvania College of Dental Surgery and in the Phila- 
 delphia Polyclmic. Cloth, .75 
 
 TEMPERATURE Charts for Recording Temperature, Respiration, Pulse, Day of 
 Disease, Date, Age, Sex, Occupation, Name, etc. Put up in pads; each .50 
 
 THOMPSON. Lithotomy and Lithotrity. Practical Lithotomy and Lithotrity ; or 
 an Inquiry into the best Modes of Removing Stone from the Bladder. By Sir 
 HENRY THOMPSON, F.R.C.S., Emeritus Professor of Clinical Surgery in Univer- 
 sity College. Third Edition. With 87 Engravings. 8vo. Cloth, $3.50 
 
 Urinary Organs. Diseases of the Urinary Organs. 7th London Ed. Cloth, $ia$ 
 
 On the Prostate. Diseases of the Prostate. Their Pathology and Treatment. 
 Sixth London Edition. Svo. Illustrated. Cloth, $2.00 
 
 Calculous Diseases. The Preventive Treatment of Calculous Disease, and 
 the Use of Solvent Remedies. Second Edition. i6mo. Cloth, $1.00 
 
 Surgery of the Urinary Organs. Some Important Points connected with the 
 Surgery of the Urinary Organs. Illus. Paper, .75; Cloth, $1.25 
 
 THOMPSON'S Manual of Physics. A Student's Manual. By SYLVANUS P 
 THOMPSON, B.A., D.SC., F.R.A.S., Professor of Experimental Physics in University 
 College, Bristol, England. Preparing. 
 
 TIDY. Modern Chemistry, Inorganic and Organic. A Handbook for the Use of 
 Students. By CHAS. MEYMOTT TIDY, F.R.C., Prof, of Chemistry and Medical 
 Jurisprudence and Public Health at London Hospital ; Medical Officer of Health 
 and Public Analyst of the City of London, etc. Svo. Second Edition. Revised 
 and Enlarged. ' Cloth, $5.50 
 
 TILT'S Change of Life in Women, in Health and Disease. A Practical Treatise 
 on the Diseases incidental to Women at the Decline of Life. By EDWARD JOHN 
 TILT, M.D. Fourth London Edition. Svo. Paper cover, .75 ; Cloth, $1.25 
 
 TOMES' Dental Anatomy. A Manual of Dental Anatomy, Human and Compara- 
 tive. By C. S. TOMES, D.D.S. 191 Illustrations. 3d Ed. I2mo. In Press. 
 
22 P. BLAKISTON, SON &- CO.'S 
 
 TOMES. Dental Surgery. A System of Dental Surgery. By JOHN TOMES, F.R.S. 
 
 Fourth Edition, Revised and Enlarged. By C. S. TOMES, D.D.S. With 292 
 
 Illustrations. I2mo. 772 pages. Cloth, $5.00 
 
 TRANSACTIONS of the College of Physicians of Philadelphia. Third Series. 
 
 Vols. I, II, III, IV, V, Cloth, each, $2.50. VI, VII, Cloth, each, $3.50. 
 
 Vol. VIII, 1886, Cloth, $3.75. 
 
 TRANSACTIONS American Surgical Association. Illustrated. Royal 8vo. 
 Price of Vol. I, Cloth, $3.50; Vol. II, Cloth, $4.00; Vol. Ill, Cloth, $3.50 Vol. IV, 
 Cloth, $3.00. Vol. V, Cloth, $4.25 
 
 TRIMBLE. Practical and Analytical Chemistry. Being a complete course in 
 Chemical Analysis. By HENRY TRIMBLE, PH.G., Professor of Analytical Chem- 
 istry in the Philadelphia College of Pharmacy. Second Edition. Enlarged. 
 Illustrated. 8vo. Cloth, $1.50 
 
 TURNBTILL'S Artificial Anaesthesia. The Advantages and Accidents of Artifi- 
 cial Anaesthesia ; Its Employment in the Treatment of Disease ; Modes of Ad- 
 ministration ; Considering their Relative Risks ; Tests of Purity ; Treatment of 
 Asphyxia ; Spasms of the Glottis ; Syncope, etc. By LAURENCE TURNBULL, M.D., 
 PH. G., Aural Surgeon to Jefferson College Hospital, etc. Second Edition, Re- 
 vised and Enlarged. With 27 Illustrations of Various Forms of Inhalers, etc., 
 and an appendix of over 70 pages, containing a full account of the new local 
 Anaesthetic, Hydrochlorate of Cocaine. I2mo. Cloth, $1.50 
 
 Hydrochlorate of Cocaine. i2mo. Paper, .50 
 
 TUSON. Veterinary Pharmacopoeia. Including the Outlines of Materia Medica 
 and Therapeutics. For the Use of Students and Practitioners of Veterinary 
 Medicine. By RICHARD V. TUSON, F.C.S. Third Edition. i2mo. Cloth, $2.50 
 TYSON. Blight's Disease and Diabetes. With Especial Reference to Pathology 
 and Therapeutics. By JAMES TYSON, M.D., Professor of Pathology and Morbid 
 Anatomy in the University of Pennsylvania. Including a Section on Retinitis in 
 Bright's Disease. By WM. F. NORRIS, M.D., Clin. Prof, of Ophthalmology, in Univ. 
 of Penna. With Colored Plates and many Wood Engravings. 8vo. Cloth, $3.50 
 Guide to the Examination of Urine. Fifth Edition. For the Use of 
 Physicians and Students. With Colored Plates and Numerous Illustrations 
 Engraved on Wood. Fifth Edition. Enlarged and Revised. I2mo. 249 
 pages. Cloth, $1.50 
 
 Cell Doctrine. Its History and Present State. With a Copious Bibliography 
 of the subject. Illustrated by a Colored Plate and Wood Cuts. Second 
 Edition. 8vo. Cloth, $2.00 
 
 Rindfleisch's Pathology. Edited by Prof. TYSON. General Pathology; a 
 Handbook for Students and Physicians. By Prof. EDWARD RINDFLEISCH, 
 of Wurzburg. Translated by WM. H. MERCUR, M.D. Edited and Revised 
 by JAMES TYSON, M.D., Professor of Morbid Anatomy and Pathology, 
 University of Pennsylvania. Cloth, $2.00 
 
 VALENTIN'S Qualitative Analysis. A Course of Qualitative Chemical Analysis. 
 By WM. G.VALENTIN, F.C.S. Sixth Edition. Revised and Corrected by W. R. 
 HODGKINSON, PH.D. (Wiirzburg), Fellow of the Institute of Chemistry, and of 
 the Chemical, Physical and Geological Societies of London ; Lecturer on 
 Chemistry in the South Kensington Science Schools. Assisted by H. M. 
 CHAPMAN, Assistant Demonstrator of Chemistry in the Royal School of Mines. 
 Illustrated. Octavo Cloth, $3.00 
 
 VAN HARLINGEN on Skin Diseases. A Practical Manual of Diagnosis and 
 Treatment. By ARTHUR VAN HARLINGEN, M.D., Professor of Diseases of the 
 Skin in the Philadelphia Polyclinic ; Consulting Physician to the Philadelphia 
 Dispensary for Skin Diseases. With Formulae and Colored Plates. I2mo. 
 
 Cloth, $1.75 
 
 VAN NITYS on The Urine. Chemical Analysis of Healthy and Diseased Urine, 
 Qualitative and Quantitative. By T. C. VAN NUYS, Professor of Chemistry 
 Indiana University. 39 Illustrations. Octavo. Cloth. In Press. 
 
MEDICAL AND SCIENTIFIC PUBLICATIONS. 23 
 
 VIRCHOWS Post-mortem Examinations. A Description and Explanation of the 
 Method of Performing them in the Dead House of the Berlin Charite Hospital, 
 with especial reference to Medico-legal Practice. By Prof. VIRCHOW. Trans- 
 lated by Dr. T. P. SMITH. Third Edition, with Additions and New Plates. 
 I2mo. 'Series of Medical Briefs, No. \. Cloth, $1.00 
 
 Cellular Pathology, as based upon Physiological and Pathological Histology. 
 20 Lectures delivered at the Pathological Institute of Berlin. Translated 
 from the 2d Ed. by F. CHANCE, M.D. 134 Illus. 8th Am. Ed. Cloth, $4.00 
 
 WALSH AM. Manual of Practical Surgery. For Students and Physicians. By 
 WM. J. WALSHAM, M.D., F.R.C.S., Asst. Surg. to, and Dem. of Practical Surg. in, 
 St. Bartholomew's Hospital, Surg. to Metropolitan Free Hospital, London. With 
 236 Engravings. 656 pages, New Series of Manuals. 
 
 Cloth, $3.00 ; Leather, $3.50 
 
 WARING. Practical Therapeutics. A Manual for Physicians and Students. By 
 Edward J. Waring, M.D. Fourth Edition. Revised, Rewritten and Rearranged 
 by DUDLEY W. BUXTON, M.D., Assistant to the Professor of Medicine, University 
 College, London. Crown Octavo. Cloth, $3.00; Leather, $3.50 
 
 WARNER. Case Taking. A Manual of Clinical Medicine and Case Taking. By 
 FRANCIS WARNER, M.D. Second Edition. Cloth, $1.75 
 
 WATSON on Amputations of the Extremities and Their Complications. By 
 B. A. WATSON, A.M., M.D., Surgeon to the Jersey City Charity Hospital and to 
 Christ's Hospital, Jersey City, N. J. ; Member of the American Surgical Associ- 
 ation. With over 250 Wood Engravings and two Full-page Colored Plates. 
 Octavo. 770 pages. Cloth, $5.50 
 
 WATTS' Inorganic Chemistry. A Manual of Chemistry, Physical and Inorganic. 
 
 (Being the i3th Edition of FOWNE'S PHYSICAL AND INORGANIC CHEMISTRY.) 
 
 By HENRY WATTS, B.A., F.R.S., Editor of the Journal of the Chemical Society ; 
 
 Author of "A Dictionary of Chemistry," etc. With Colored Plate of Spectra 
 
 and other Illustrations. I2mo. 595 pages. Cloth, $2.25 
 
 Organic Chemistry. Second Edition. By WM. A. TILDEN, D.SC., F.R.S. 
 
 (Being the i3th Edition of FOWNE'S ORGANIC CHEMISTRY). Illustrated. 
 
 I2mo. Cloth, $2.25 
 
 WELCH'S Enteric Fever. Its Prevalence and Modifications; Etiology, Pathology 
 and Treatment. By FRANCIS H. WELCH, F.R.C.S. 8vo. Cloth, $2.00 
 
 WHITE. The Mouth and Teeth. By J. W. WHITE, M.D., D.D.S. Editor of the 
 Dental Cosmos. Illustrated. Cloth, .50 
 
 WICKES' Sepulture. Its History, Methods and Sanitary Requisites. By STEPHEN 
 WICKES, A.M., M.D. Octavo. Cloth, $1.50 
 
 WILKES' Pathological Anatomy. Lectures on Pathological Anatomy. By SAMUEL 
 WILKES, F.R.S. Second Edition, Revised and Enlarged by WALTER MOXON, 
 M.D., F.R.S., Physician to and Lecturer at Guy's Hospital, London. Cloth, 6.00 
 The Nervous System. Lectures on Diseases of the Nervous System, Deliv- 
 ered at Guy's Hospital, London. New Edition. 8vo. Cloth, $6.00 
 
 WILLIAMS. Pulmonary Consumption. Its Etiology, Pathology and Treatment, 
 with an Analysis of 1000 Cases to Exemplify its Duration and Modes of Arrest. 
 By C. J. B. WILLIAMS, M.D., LL.D., F.R.S., Senior Consulting Physician to the 
 Hospital for Consumption and Diseases of the Chest, Brompton ; formerly Prof, 
 of Med. University Col., London, etc. Second Edition. Enlarged and Rewritten. 
 By C. THEODORE WILLIAMS, M.D., F.R.C.P., Physician to Hospital for Consump- 
 tion and Diseases of the Chest, Brompton, etc. With 4 Colored Plates and other 
 Illustrations. Octavo. Cloth, 5.00 
 
 WILSON. The Summer and Its Diseases. By JAMES C. WILSON, M.D. Cloth, .50 
 
 WILSON'S Text-Book of Domestic Hygiene and Sanitary Information. A Guide 
 
 to Personal and Domestic Hygiene. By GEORGE WILSON, M.D., Medical Officer 
 
 of Health. Edited by Jos. G. RICHARDSON, M.D., Professor of Hygiene at the 
 
 University of Pennsylvania. Cloth, $1.00 
 
 Handbook of Hygiene and Sanitary Science. With Illustrations. Sixth 
 
 Edition, Revised and Enlarged. 8vo. Cloth, $2.75 
 
24 P. J5LAKISTON, SON & CO:S PUBLICATIONS. 
 
 WILSON. Human Anatomy, The Anatomist's Vade-mecum. General and Spe- 
 cial. By Prof. ERASMUS WILSON. Edited by GEORGE BUCHANAN, Professor of 
 Clinical Surgery in the University of Glasgow; and HENRY E. CLARK, Lecturer 
 on Anatomy at the^Royal Infirmary School of Medicine, Glasgow. Tenth Edi- 
 tion. With 450 Engravings (including 26 Colored Plates). Cloth, $6.00 
 Healthy Skin and Hair. A Practical Treatise. Their Preservation and 
 Management. Eighth Edition. I2mo. Paper, $1.00 
 
 WINCKEL-PARVIN. Diseases of Women. By Dr. F. WINCKEL, Professor of 
 Gynaecology, and Director of the Royal University Clinic for Women, in Munich. 
 Translated by special authority of Author and Publisher, by Dr. J. H. WILLIAM- 
 SON, Resident Physician of Allegheny General Hospital, Allegheny, Pa., under 
 the supervision of, and with an Introduction by, THEOPHILUS PARVIN, M.D., 
 Professor of Obstetrics and Diseases of Women and Children in Jefferson 
 Medical College, Philadelphia. With 132 Engravings on Wood, most of which 
 are entirely new. Demi-octavo. Cloth, $3.00; Leather, $3.50 
 
 WOAKES. Post-Nasal Catarrh and Diseases of the Nose, causing Deafness. By 
 
 EDWARD WOAKES, M.D., Senior Aural Surgeon to the London Hospital for 
 
 Diseases of the Throat and Chest. 26 Illustrations. Cloth, $1.50 
 
 Nasal Polypus, with Neuralgia, Hay Fever and Asthma in Relation to 
 
 Ethmoiditis. I2mo. Cloth, $1.25 
 
 On Deafness, Giddiness and Noises in the Head, or the Naso-Pharyngeal 
 
 aspect of Ear Disease. Third Edition. Illustrated. In Press. 
 
 WOLFF. Manual of Applied Medical Chemistry for Students and Practitioners of 
 Medicine. By LAWRENCE WOLFF, M.D., Demonstrator of Chemistry in Jeffer- 
 son Medical College, Philadelphia. Cloth, $1.50 
 
 WOOD. Brain Work and Overwork. By Prof. H. C. WOOD, Clinical Professor 
 of Nervous Diseases, University of Pennsylvania. I2mo. Cloth, .50 
 
 WOODMAN and TIDY. Medical Jurisprudence. Forensic Medicine and Toxi- 
 cology. By W. BATHURST WOODMAN, M.D., Physician to the London Hospital, 
 and CHARLES MEYMOTT TIDY, F.C.S., Professor of Chemistry and Medical Juris- 
 prudence at the London Hospital. With Chromo-lithographic Plates, represent- 
 ing the Appearance of the Stomach in Poisoning by Arsenic, Corrosive Subli- 
 mate, Nitric Acid, Oxalic Acid ; the Spectra of Blood and the Microscopic Ap- 
 pearance of Human and other Hairs; and 116 other Illustrations. Large 
 Octavo. Sold by Subscription. Cloth, $7.50; Leather, $8. 50 
 
 WEIGHT on Headaches ; their Causes, Nature and Treatment. By HENRY G. 
 WRIGHT, M.D. i2mo. Cloth, .50 
 
 WYTHE on the Microscope. A Manual of Microscopy and Compendium of the 
 Microscopic Sciences, Micro-mineralogy, Biology, Histology and Practical Medi- 
 cine, with Index and Glossary and the genera of microscopic plants. By JOSEPH 
 H. WYTHE, A.M., M.D. Fourth Edition. 252 Illus. Cloth, $3.00; Leather, $4.00 
 Dose and Symptom Book. The Physician's Pocket Dose and Symptom Book. 
 Containing the Doses and Uses of all the Principal Articles of the Materia 
 Medica, and Original Preparations, i/th Edition, Revised and Rewritten 
 Just Ready. Cloth, $1.00; Leather, with Tucks and Pocket, $1.25 
 
 YEO'S Manual of Physiology. Second Edition. A Text-book for Students of 
 Medicine. By GERALD F. YEO., M.D. F.R.C.S., Professor of Physiology in King's 
 College, London. Second Edition ; revised by the author. With over 300 care- 
 fully printed Illustrations. A Glossary and Complete Index. Crown Octavo. 
 New Series of Manuals. Cloth, $3.00 ; Leather, $3.50 
 
 "After a careful examination of this Manual of Physiology, I can truthfully say that it is a most valuable 
 addition to the list of text-books upon this subject. That it should and will receive a welcome from both 
 students and teachers there can be no doubt. The author presents his subject in a manner that is clear, 
 concise and logical. Each section has had a careful revision, and reveals the author's familiarity with 
 the scope and tendencies of modern physiology." A, P. Brubaker, M.D,. De-ntonstrator of Physiology 
 at Jeff er ton Medical College, Philadelphia. 
 
Holden's Manual of Anatomy. 
 
 FIFTH EDITION, REVISED AND ENLARGED. 208 ILLUSTRATIONS. 
 A MANUAL OF THE DISSECTIONS OF THE HUMAN BODY. 
 
 By LUTHER HOLDEN, M.D., F.R.C.S., Consulting Surgeon to St. Bartholomew's and the 
 Foundling Hospitals, London, and JOHN LANGTON, F.R.C.S., Surgeon to and Lec- 
 turer in St. Bartholomew's Hospital. Fifth Edition. Revised and Enlarged, with 
 many new Illustrations. Octavo. OIL CLOTH BINDING, $4.50 
 
 Cloth, $5.00; Leather, $6.00 
 
 * # * As Holders Anatomy is the chief " Dissector " now in use, the publishers have 
 put it in an Oil Cloth Binding. This does not retain the odors of the dissecting room, 
 is not easily soiled, and may be washed without damage. 
 
 DIAGRAM OF AXILLA 
 (From Holden's Anatomy) 
 
 THORACICA HUMERARIA ARTERY. 
 
 4. SUPERIOR THORACIC ARTERY. 
 
 5. SUBSCAPULAR ARTHRY. 
 
 6. DORSALIS SCAPULA ARTERY. 
 
 Z. POSTERIOR CIRCUMFLEX ARTBRY. 
 . SUPERIOR PROFUNDA ARTERY. 
 9. POSTERIOR THORACIC NBRVB. 
 
 10. LONG SUBSCAPULAR NERVE. 
 
 11. MEDIAN NERVE. 
 
 12. CEPHALIC VEIN. 
 
 13. MUSCULO-CUTANBOUS NBRVB. 
 
 14. TERES MAJOR. 
 
 " No student of anatomy can take up this book without being pleased and instructed. Its diagrams are original. 
 striking and suggestive, giving more at a glance than pages of text description. All this is known to those who 
 are already acquainted with this admirable work ; but it is simple justice to its value, as a work for careful study 
 and reference, that these points be emphasized to such as are commencing their studies. The text matches the 
 illustrations in directness of practical application and clearness of detail." New York Medical Record, April 
 
 HUMAN OSTEOLOGY. Comprising a description of the Bones, with Colored Delinea- 
 tions of the Attachments of the Muscles. The General and Microscopical Structure of 
 Bone and its Development. Carefully Revised. By the Author and A. DORAN, F.R.C.S., 
 with Lithographic Plates and Numerous Illustrations. Sixth Edition. 8vo. Cloth, $6.00 
 
 HEATH'S PRACTICAL ANATOMY. A Manual of Dissections. Sixth London Edi- 
 tion. 24 Colored Plates, and nearly 300 other Illustrations. Cloth, $5.00 
 
 P. BLAKISTON, SON & CO., 1012 Walnut St., Philadelphia. 
 
THE NEW SERIES OF MANUALS 
 
 FOR MEDICAL, STUDENTS AND PHYSICIANS. 
 
 Demi-Octavo. Price of each book, Cloth, $3.00 ; Leather, $3.50. 
 
 The object held in view in the preparation of this Series was to make books that should be 
 
 concise and practical, not burdened by useless theories and discussions, but containing all that is 
 
 needed or necessary for the student and practitioner. No pains have been spared to bring them 
 
 up to the times, and the very low price at which they have been published, is an additional point 
 
 in their favor. Full circular, descriptive of the Series, will be sent upon application. 
 
 GALABIN'S MIDWIFERY. A Manual of Midwifery. By ALFRED LEWIS GALABIN, 
 M.A., M.D., Obstetric Physician and Lecturer on Midwifery and the Diseases of Women at 
 Guy's Hospital, London; Examiner in Midwifery to the Conjoint Examining Board of 
 England. 227 Illustrations. 753 pages. Cloth, $3.00; Leather, $3.50 
 
 GOODHART AND STARR, DISEASES OF CHILDREN. By J. F. GOODHART, 
 M.D., Physician to the Evelina Hospital for Children; Assistant Physician to Guy's Hospi- 
 tal, London. American Edition. Revised and Edited by Louis STARR, M.D., Clinical 
 Professor of Diseases of Children in the Hospital of the University of Pennsylvania, and 
 Physician to the Children's Hospital, Phila. With many new Prescriptions and over 50 
 Formulae, conforming to the U. S. Pharmacopoeia, and Directions for making Artificial 
 Human Milk, for the Artificial Digestion of Milk, etc. 738 pages. Cloth, $3.00; Leather,$3.5o 
 
 POTTER'S MATERIA MEDICA, PHARMACY AND THERAPEUTICS. A 
 Handbook of Materia Medica, Pharmacy and Therapeutics, including the Physiological 
 Action of Drugs, Special Therapeutics of Diseases, Official and Extemporaneous Pharmacy, 
 etc., etc. By SAM'L O. L. POTTER, M.A., M.D., Professor of Practice, Cooper Medical 
 College, San Francisco; Author of "Quiz-Compends" of Anatomy and Materia Medica, 
 etc. With 600 Prescriptions and an Appendix containing numerous Tables comprising 
 doses, diagnostics, Latin terms, formulae for hypodermics, metric equivalents, specific gravi- 
 ties and volumes, and obstetric memoranda together with Notes on temperature and the 
 clinical thermometer, poisons, urinary examinations and patent medicines, etc. 830 
 pages. Cloth, $3.00; Leather, $3.50 
 
 REESE'S MEDICAL JURISPRUDENCE AND TOXICOLOGY. By JOHN J. 
 REESE, M.D., Professor of Medical Jurisprudence and Toxicology in the University of Penn- 
 sylvania; Vice- President of the Medical Jurisprudence Society of Philadelphia; Physician to 
 St. Joseph's Hospital; Member of the College of Physicians of Phila.; Corresponding Mem- 
 ber of the New York Medico- Legal Society, etc. 606 pages. Cloth, $3.00; Leather, $3.50 
 
 RICHTER'S ORGANIC CHEMISTRY. By PROF. VICTOR VON RICHTER, University 
 of Breslau. Authorized translation. First American, from the Fourth German Edition. 
 By EDGAR F. SMITH, M.A., PH.D., Translator of Richter's Inorganic Chemistry; Prof, of 
 Chemistry in Wittenberg College, Springfield, Ohio ; formerly in the Laboratories of the 
 University of Pennsylvania; Member of the Chemical Societies of Berlin and Paris, of the 
 Academy of Natural Sciences of Philadelphia, etc. Illustrated. 710 pages. 
 
 Cloth, $3.00; Leather, $3.50 
 
 WARING'S PRACTICAL THERAPEUTICS. Fourth Edition. A Manual of 
 Practical Therapeutics, considered with reference to Articles of the Materia Medica. Con- 
 taining, also, an Index of Diseases, with a list of. the Medicines applicable as Remedies, and 
 a full Index of the Medicines and Preparations noticed in the work. By EDWARD JOHN 
 WARING, M.D.,F.R.C.P.,F.L.S., etc. 4th Edition. Rewritten and Revised. Edited by DUDLEY 
 . W. BUXTON, M.D., Asst. to the Prof, of Medicine at University College Hospital; Member 
 of the Royal College of Physicians of London. 666 pages. Cloth, $3.00; Leather, $3.50 
 
 PARVIN'S-WINCKEL'S DISEASES OF WOMEN. A Treatise on the Diseases of 
 Women. By DR. F. WINCKEL, Professor of Gynaecology and Director of the Royal Uni- 
 versity Clinic for Women, in Munich. Translated from the German by DR. J. H. WIL- 
 LIAMSON, Resident Physician Allegheny General Hospital, Allegheny, Penn'a, under the 
 supervision of, and with an Introduction by, THEOPHILUS PARVIN, M.D., Professor of Ob- 
 stetrics and Diseases of Women and Children in Jefferson Medical College. Illustrated by 
 117 fine Engravings on Wood, most of which are new. 674 pp. Cloth, $3.00; Leather, $3. 50 
 
 YEO'S MANUAL OF PHYSIOLOGY. Second Edition. A New Text-book for 
 Students. By GERALD F. YEO, M.D., F.R.C.S., Professor of Physiology in King's College, 
 London. Over 301 Illustrations and a Glossary. 743 pages. Cloth, $3.00; Leather, $3.50 
 
 WALSHAM'S PRACTICAL SURGERY. A Manual for Students and Physicians. By 
 WM. J. WALSHAM, M.D., Asst. Surgeon to, and Demonstrator of Surgery in, St. Barthol- 
 omew's Hospital ; Surgeon to Metropolitan Free Hospital, London, etc. With 236 Illus- 
 trations. 656pp. Cloth, $3.00; Leather, $3.50 
 *.* Any of these books may be obtained from booksellers upon receipt of price. Any book 
 
 will be sent, postage prepaid. Full catalogues upon application. 
 
 P. BLAKISTON, SON & CO., Medical Publishers, Booksellers and importers, 
 1012 WALNUT STREET, PHILADELPHIA. 
 
NEW CHEMICAL BOOKS. 
 
 PREPARED ESPECIALLY FOR THE WANTS OF MEDICAL, DENTAL AND PHARMA. 
 CEUTICAL STUDENTS AND PRACTITIONERS. 
 
 A Text-Book of Medical Chemistry. 
 
 BY E. H. HARTLEY, M.D., 
 
 Associate Professor of Chemistry at the Long Island College Hospital ; President of the American Society of 
 Public Analysts ; Chief Chemist, Board of Health, of Brooklyn, N. Y., etc. 
 
 Illustrated 12mo. Cloth, $2.5O. 
 
 This book, written especially for students and physicians, aims to be a text-book 
 for the one and a work of reference for the other. It is practical and concise, dealing 
 only with those parts of chemistry pertaining to medicine ; no time being wasted in 
 long descriptions of substances and theories of interest only to the advanced chemi- 
 cal student. 
 
 PART I Treats of Light, Heat and Electricity, which are described at some length, and explanations made 
 and applied to common phenomena. In the subject of light, only so much is given as will explain the theory 
 and use of the spectroscope. In electricity, the principal aim has been to give such information as is needed 
 for the proper understanding, working and care of the medical battery. 
 
 PART II Theoretical Chemistry. Only such portions of the well established principles of modern chemistry 
 as are necessary to an understanding of the subject are given. It has been deemed best to present all these 
 elementary parts first, that the student may be better able to study any set of isolated facts. These theories 
 are presented in a concise, clear way, in a logical order and in a manner which the author has found specially 
 successful in an experience of over twelve years of teaching. 
 
 PART III Treats of the natural history of the elements, of their principal compounds, with their physiological 
 action and toxicology. 
 
 PART IV Organic bodies commonly used in medicine and pharmacy. The principal organic substances 
 derived from animal life are given a place. In the appendix will be found analyses of the principal secretions 
 and tissues, tables of solubilities and of specific gravities, the metric system, and other useful information. 
 
 Applied Medical Chemistry. 
 
 Containing a description of the apparatus and methods employed in the practice 
 of Medical Chemistry, the Chemistry of Poisons, Physiological and Pathological 
 Analysis, Urinary and Fecal Analysis, Sanitary Chemistry and the Examination of 
 Medicinal Agents, Foods, etc. 
 
 BY LAWRENCE WOLFF, M.D., 
 
 Demonstrator of Chemistry in the Jefferson Medical College ; Member of the Philadelphia College of Pharmacy 
 and of the Chemical Section of the Franklin Institute, etc. 
 
 Octavo, Cloth, $1 5O. 
 
 VThe object 01 the author of this book is to furnish the practitioner and student 
 a reliable and simple guide for making analyses and examinations of the various 
 medicinal agents, human excretions, secretions, etc., without elaborate apparatus or 
 expensive processes. 
 
 Practical and Analytical Chemistry. 
 
 Being a complete course in Chemical Analysis, for pharmaceutical and medical 
 students. 
 
 BY HENRY TRIMBLE, Ph.G., 
 Professor of Analytical Chemistry in the Philadelphia College of Pharmacy. 
 
 Second Edition. Illustrated. 8vo. Cloth, $1.5O. 
 
 SUMMARY OF CONTENTS. Part I. Practical Preparation and Properties of Gases, Preparation of Salts, 
 etc. Part II. Section I Bases. Group I Potassium, Sodium, Lithium, Ammonium. Group II Barium, 
 
 Detection of Bases and Acids. Section IV Some of the Reactions and Tests of Purity of the more import- 
 ant Organic Compounds. Part III. Quantitative Chemical Analysis. Section I Gravimetric Estimation. 
 Section II Volumetric Estimation. There are also a number of useful Tables. 
 
 LEFFMANN'S ORGANIC AND MEDICAL CHEMISTRY. Including 
 Urine Analysis and the Analysis of Water and Food. By HENRY LEFFMANN, 
 M.D., Demonstrator of Chemistry at Jefferson Medical College, Philadelphia. 
 I2mo. Cloth, $1.00; Interleaved for the addition of Notes, $1.2$ 
 
 P. BLAKISTON, SON & CO., 1012 "Walnut St., Philadelphia. 
 
Practical Handbooks 
 
 FOR THE PHYSICIAN AND MEDICAL STUDENT. 
 
 VAN HARLINGEN ON SKIN DISEASES. A Handbook of the Diag- 
 nosis and Treatment of Skin Diseases. By ARTHUR VAN HARLINGEN, M.D., 
 Professor of Diseases of the Skin in the Philadelphia Polyclinic; Consulting 
 Physician to the Philadelphia Dispensary for Skin Diseases, and Dermatologist 
 to the Howard Hospital. With colored plates representing the appearance of 
 various lesions. I2mo. Cloth, $1.75 
 
 *** This is a complete epitome of skin diseases, arranged in alphabetical order, 
 giving the diagnosis and treatment in a concise, practical way. Many prescriptions 
 are given that have never been published in any text-book, and an article incorporated 
 on Diet. The plates do not represent one or two cases, but are composed of a num- 
 ber of figures, accurately colored, showing the appearance of various lesions, and 
 will be found to give great aid in diagnosing. 
 
 ^" This new handbook is essentially a small encyclopaedia. * * * Contains a very complete summary of the 
 present state of Dermatology. * * * We heartily commend it for its brevity, clearness and evidently careful 
 preparation." Philadelphia Medical Times. 
 
 " The author shows a proper appreciation of the wants of the general practitioner." New York Medical 
 Record. 
 
 " It is concisely and intelligently written, and contains many of the best formulas in use for the various forms 
 of Skin Disease." New York Medical Times. 
 
 " This is an excellent little book, in which, for ease of reference, the more common diseases of the skin are 
 arranged in alphabetical order, while many good prescriptions are given, together with clear and sensible direc- 
 tions as to their proper application." Boston Medical and Surgical Journal. 
 
 " It is just the kind of book that the general practitioner will find most convenient for reference, and we feel 
 confident that it will be appreciated." Southern Practitioner. 
 
 RINDFLEISCH'S PATHOLOGY. The Elements of Pathology. By PROF. 
 EDWARD RINDFLEISCH, University of Wiirzburg. Authorized translation from 
 the first German edition, by WM. H. MERCUR, M.D. (Univ. of Pa.) Revised by 
 JAMES TYSON, M.D., Professor of Pathology and Morbid Anatomy in the Univer- 
 sity of Pennsylvania. I2mo. Cloth, $2.00 
 
 Prof. Tyson, in his Preface to the American edition, says : "A high appreciation of Prof. Rindfleisch's 
 work on Pathological Histology, caused me to make careful examination of these ' Elements' immediately after 
 their publication in the original. From such an examination I became satisfied that the book would fill a niche 
 in the wants of the student, as well as of others who may desire to familiarize themselves with general patho- 
 logical processes, viewed from the most modern standpoint." 
 
 BRUEN'S PHYSICAL DIAGNOSIS. Second Edition. A Pocket-book 
 of Physical Diagnosis of the Heart and Lungs ; for the Student and Physician. 
 By EDWARD T. BRUEN, Demonstrator of Clinical Medicine in the University of 
 Pennsylvania ; Lecturer on Pathology in the Women's Medical College of Phila- 
 delphia ; 2d Edition, revised, with new original illustrations. I2mo. Cloth, $1.50 
 
 " We consider the description of the manner and rules governing the art of percussion well given. The sub- 
 ject is always a difficult one for beginners, and requires to be well handled in order to be properly understood." 
 American jfournal of Medical Sciences. 
 
 WOAKES ON CATARRH AND DISEASES OP THE NOSE CAUS- 
 ING DEAFNESS. By EDWARD WOAKES, M.D.. Senior Aural Surgeon to 
 the London Hospital for Diseases of the Throat and Chest. 29 Illustrations. 
 I2mo. Cloth, $1.50 
 
 " Out of the large number of special works on catarrh, there is none for which we have such an unqualified 
 good opinion. * * * The subject is clearly presented. * The line of treatment suggested is rational." 
 North Carolina Mtdical Journal. 
 
 P. BLAKISTON, SON & CO., 10x2 Walnut St., Philadelphia. 
 
THE PRACTICAL SERIES. 
 
 TWO NEW VOLUMES JUST READY. 
 
 V* The volumes of this series, written by well-known physicians and surgeons of 
 large private and hospital experience, recognized authorities on the subjects of which 
 they treat, will embrace the various branches of medicine and surgery. They are of 
 a thoroughly practical character, calculated to meet the requirements of the practi- 
 tioner, and will present the most recent methods and information in a compact shape 
 and at a low price. 
 
 Bound Uniformly, in a Handsome and Distinctive Cloth Binding. 
 
 TREATMENT OP DISEASE IN CHILDREN. Including the Outlines 
 of Diagnosis and the Chief Pathological Differences between Children and 
 Adults. By ANGEL MONEY, M. D., M.R.C.P., Assistant Physician to the Hospital 
 for Sick Children, Great Ormond St., and to the Victoria Park Chest Hospital, 
 London. I2mo. 560 pages. Cloth, $3.00 
 
 ON FEVERS. A Practical Treatise on Fevers, Their History, Etiology, Diag- 
 nosis, Prognosis and Treatment. By ALEXANDER COLLIE, M.D., M.R.C.P., Lond. 
 Medical Officer Homerton Fever Hospital, and of the London Fever Hospital. 
 With Colored Plates. Cloth, $2.50 
 
 " This volume, which forms one of the ' Practical Series' of Medical and Surgical Manuals, deserves attention, 
 from the fact that its author has been so long devoted to the subjects of which it treats. He is, therefore, in 
 position to speak with authority as well as with complete freedom and independence. * * * * The strongest 
 parts of the work are those which deal with diagnosis and treatment, for here Dr. Collie is thoroughly at home r 
 and succeeds in imparting to the work its 'practical character, for which it will be highly valued.' " London 
 Lancet, April 23d, 1887. 
 
 HANDBOOK OP DISEASES OP THE EAR. By URBAN PRITCHARD,. 
 M.D., F.R.C.S., Professor of Aural Surgery, King's College, London, Aural Sur- 
 geon to King's College Hospital, Senior Surgeon to the Royal Ear Hospital, etc. 
 I2mo. Cloth, $1.50 
 
 " Exactly what is wanted at the present moment, we can recommend every practitioner to have a copy." 
 London Practitioner. 
 
 "A first-rate little book. * * * The man who wants a short, reliable book will buy Dr. Pritchard's." 
 New Orleans Medical and Surgical Journal. 
 
 "Written from an eminently practical standpoint. * * * * Commended for its simplicity and directness." 
 New York Medical Journal . 
 
 " Belongs to a class that is very useful to the general practitioner." Maryland Medical Journal. 
 
 DISEASES OP THE KIDNEYS, AND URINARY DERANGE- 
 MENTS. By C. H. RALFE, M.A., M.D., F.R.C.P., Assistant Physician to the 
 London Hospital ; late Senior Physician to the Seamen's Hospital, Greenwich. 
 I2mo. With Illustrations. 572 pages. Cloth, $2.75, 
 
 " It is with keen pleasure that we recommend this really meritorious book to our readers." New York Medical 
 Journal. 
 
 "A clear, concise and systematic account of urinary pathology and therapeutics. * * * * The student 
 will find in these pages all necessary instruction imparted in a candid and not dogmatic manner, and the practi- 
 tioner will find a ready and convenient reference book." Boston Medical and Surgical Journal. 
 
 BODILY DEFORMITIES AND THEIR TREATMENT. A Handbook 
 of Practical Orthopaedics. By H. A. REEVES, F.R.C.S., Senior Assistant Surgeon 
 and Teacher of Practical Surgery at the London Hospital ; Surgeon to the Royal 
 Orthopaedic Hospital, etc. I2mo. 228 Illustrations. 460 pages. Cloth, $2.25 
 
 " From what we have already said, it will be seen that Mr. Reeves has given us a trustworthy guide for the 
 treatment of a very extended class of cases. * * * * If the other volumes of the Practical Series are as good 
 as this, we shall be agreeably disappointed." American Journal of Medical Sciences, April, fSSj. 
 
 " The utility of the work now before us cannot be better recommended to the appreciation of the professional 
 reading public than by recalling that it is the first of its kind, dealing with orthopaedics from a modern stand- 
 point." Hospital Gazette and Students' Journal. 
 
 DENTAL SURGERY FOR GENERAL PRACTITIONERS AND 
 STUDENTS IN MEDICINE. By ASHLEY W. BARRETT, M.D., M.R.C.S., 
 ENG., Surgeon-Dentist to, and Lecturer on Dental Surgery and Pathology in the 
 Medical School of, London Hospital. I2mo. Illustrated. Cloth, $1.00 
 
 " Replete with an abundance of practical information of unquestionable utility." Hospital Gazette and 
 Students' Journal. 
 
 P. BLAKISTON, & SON CO., 1012 Walnut St., Philadelphia. 
 
PERIODICALS PUBLISHED BY P. BLAKISTON, SON & CO. 
 
 THE POLYCLINIC. Vol. V. 
 
 A Monthly Journal of Medicine and Surgery. Doubled in Size Without Increase of Price. 
 
 $1.00 PER ANNUM. SAMPLE COPIES FREE. 
 
 EDITORIAL STAFF. 
 EDITOR-IN-CHIEF, HENRY LEFFMANN, M.D. 
 
 Diseases of the Throat and Chest. J. SOLIS-COHEN, M.D., Professor of Dis- 
 eases of the Throat and Chest in the Philadelphia Polyclinic. 
 
 General Surgery, Orthopaedics, Operative and Clinical Surgery. JOHN 
 B. ROBERTS, M.D., Surg. to St. Mary's Hosp. ; CHAS. B. NANCREDE, M.D., Surg. 
 to the Episcopal and to St. Christopher's Hosps. ; LEWIS W. STEINBACH, M.D., 
 WM. BARTON HOPKINS, M.D., Asst. Demonstrator of Surgery, Univ. of Penna., 
 A. B. HIRSH, M.D. 
 
 Diseases of the Bar. CHARLES H. BURNETT, M.D., Aural Surgeon to the Presby- 
 terian Hospital. 
 
 Diseases of the Mind and Nervous System. CHARLES K. MILLS, M.D., Lec- 
 turer on Mental Diseases, University of Pennsylvania ; Consulting Physician 
 Insane Department, Philadelphia Hospital. 
 
 Diseases of the Skin. ARTHUR VAN HARLINGEN, M.D., Consulting Physician 
 Dispensary for Skin Diseases ; Physician to Howard Hosp. Dermatological Dept. 
 
 Diseases of the Bye. GEORGE C. HARLAND, M.D., Surgeon to Wills Eye Hospi- 
 tal and to the Eye and Ear Dept., Penna. Hosp.; HOWARD F. HANSELL, M.D., 
 Physician to Southeastern Hospital and Manayunk Eye and Ear Dispensary. 
 
 Genito-Urinary and Venereal Diseases. J. HENRY C. SIMES, M.D., Surgeon 
 to Episcopal Hospital. 
 
 Clinical Medicine. FREDERICK P. HENRY, M.D., Physician to Episcopal Hospital. 
 
 G-ynsecology and Obstetrics. BENJ. F. BAER, M.D., late Instructor in Gynaecol-' 
 ogy, University of Pennsylvania ; Obstetrician to Maternity Hospital. 
 
 Diseases of Women and Children. WASHINGTON H. BAKER, M.D., Obstet- 
 rician to Maternity Hospital. 
 
 A SPECIAL/ OFFER. T each new subscriber, who remits one dollar, in 
 
 * advance, we will send THE POLYCLINIC for one 
 
 year and A COPY OF THE FOLLOWING BOOK : Urinary and Renal Derangements 
 and Calculous Disorders, with Hints on Diagnosis and Treatment. By 
 
 LIONEL S. BEALE, M.D., F.R.S., F.R.C.P., Professor of the Principles and Practice of 
 Medicine in King's College, London ; Physician to King's College Hospital. I2mo. 
 356 pages. 1885. Bound in strong paper covers. 
 
 The Journal of Laryngology and Rhinology. 
 
 An Analytical Record of Current Literature Relating to the Throat and Nose. Edited by MORELL 
 MACKENZIE, M.D., Lond., and R. NORRIS WOLFENDEN, M.D., Cantab. 
 
 "With. the Co-operation of Dr. FAUVEL (Paris), Dr. JOAL (Paris), Prof. MASSEI 
 (Naples), Prof. GUYE (Amsterdam), Dr. CAPART (Brussels), Dr. HUNTER MACKENZIE 
 (Edinburgh), Dr. MICHAEL (Hamburg), Dr. RAMON DE LA SOTA Y LASTRA (Seville), 
 Dr. JOHN N. MACKENZIE (Baltimore), Dr. HOLGER MYGIND (Copenhagen), Dr. 
 SMYLY (Dublin), and Dr. GREVILLE MACDONALD (London). 
 
 PUBLISHED MONTHLY. PER ANNUM, $3.00. SAMPLE NUMBERS, 250. 
 
 THE OPHTHALMIC REVIEW. 
 
 A Monthly Record of Ophthalmic Science. 
 
 Edited by JAMES ANDERSON, M.D. , London ; KARL GROSSMANN, Liverpool; PRIESTLEY 
 SMITH, Birmingham, and JOHN B. STORY, M.D., Dublin. 
 
 MONTHLY. SUBSCRIPTION PER ANNUM, $3.00. 
 
 The OPHTHALMIC REVIEW is the only Journal devoted to this special branch of 
 medicine that is published in Great Britain, and therefore represents the advances 
 made in that country as no other periodical can. Sample numbers, 25 cents. 
 
? QUIZ-COMPENDS ? 
 
 A NEW SEEIES OF PRACTICAL MANUALS FOE THE PHYSICIAN AND STUDENT, 
 
 Compiled in accordance with the latest teachings of prominent lecturers 
 and the most popular Text-books. 
 
 They form a most complete, practical and exhaustive set of manuals, containing information 
 nowhere else collected in such a condensed, practical shape. Thoroughly up to the times in 
 every respect, containing many new prescriptions and formulae, and over two hundred and thirty 
 illustrations, many of which have been drawn and engraved specially for this series. The 
 authors have had large experience as quiz-masters and attaches of colleges, with exceptional 
 opportunities for noting the most recent advances and methods. The arrangement of the sub- 
 jects, illustrations, types, etc., are all of the most approved form, and the size of the books is 
 such that they may be easily carried in the pocket. They are constantly being revised, so as to 
 include the latest and best teachings, and can be used by students of any college of medicine, 
 dentistry or pharmacy. 
 
 Bound in Cloth, each $1.00. Interleaved, for the Addition of Notes, $1.25. 
 
 No. i. Human Anatomy. Fourth Edition, including Visceral Anatomy, formerly 
 published separately. Over 100 Illustrations. By SAMUEL O. L. POTTER, M.A., M.D., 
 late A. A. Surgeon U. S. Army. Professor of Practice, Cooper Med. College, San Francisco. 
 
 Nos. 2 and 3. Practice of Medicine. Second Edition. By DANIEL E. HUGHES, M.D., 
 Demonstrator of Clinical Medicine in Jefferson Med. College, Phila. In two parts. 
 
 PART I. Continued, Eruptive and Periodical Fevers, Diseases of the Stomach, Intestines, Peritoneum, 
 Biliary Passages, Liver, Kidneys, etc. (including Tests for Urine), General Diseases, etc. 
 
 PART II. Diseases of the Respiratory System (including Physical Diagnosis), Circulatory System and Ner- 
 vous System ; Diseases of the Blood, etc. 
 
 %* These little books can be regarded as a full set of notes upon the Practice of Medicine, containing the 
 Synonyms, Definitions, Causes, Symptoms, Prognosis, Diagnosis, Treatment, etc., of each disease, and including 
 a number of prescriptions hitherto unpublished. 
 
 No. 4. Physiology, including Embryology. Fourth Edition. By ALBERT P. BRUBAKER, 
 M.D., Prof, of Physiology, Penn'a College of Dental Surgery ; Demonstrator of Physiology 
 in Jefferson Med. College, Phila. Revised, Enlarged and Illustrated. 
 
 No. 5. Obstetrics. Illustrated. Third Edition. For Physicians and Students. By 
 HENRY G. LANDIS, M.D., Prof, of Obstetrics and Diseases of Women, in Starling Medical 
 College, Columbus. Revised Edition. New Illustrations. 
 
 No. 6. Materia Medica, Therapeutics and Prescription Writing. Fourth Revised 
 Edition. With especial Reference to the Physiological Action of Drugs, and a complete 
 article on Prescription Writing. Based on the Last Revision (Sixth) of the U. S. Pharma- 
 copoeia, and including many unofficinal remedies. By SAMUEL O. L. POTTER, M.A., M.D., 
 late A. A. Surg. U. S. Army ; Prof, of Practice, Cooper Med. College, San Francisco. 4th 
 Edition, with Index. 
 
 No. 7. Gynaecology. A Compend of Diseases of Women. By HENRY MORRIS, M.D., 
 Demonstrator of Obstetrics, Jefferson Medical College, Philadelphia. In Press. 
 
 No. 8. Diseases of the Eye and Refraction, including Treatment and Surgery. By L. 
 WEBSTER Fox, M.D., Chief -Clinical Assistant Ophthalmological Dept., Jefferson Medical 
 College, etc., and GEO. M. GOULD, A.B. 40 Illustrations. 
 
 No. 9. Surgery. Illustrated. Third Edition. Including Fractures, Wounds, Disloca- 
 tions. Sprains, Amputations and other operations; Inflammation, Suppuration, Ulcers. 
 Syphilis, Tumors, Shock, etc. Diseases of the Spine, Ear, Bladder, Testicles, Anus, and 
 other Surgical Diseases. By ORVILLE HORWITZ, A.M., M.D., Demonstrator of Anatomy, 
 Jefferson Medical College. Third Edition. Revised and Enlarged. 77 Formulae and 91 
 Illustrations. 
 
 No. 10. Organic Chemistry. Including Medical Chemistry, Urine Analysis, and the Analy- 
 sis of Water and Food, etc. By HENRY LEFFMANN, M.D., Demonstrator of Chemistry in 
 Jefferson Med. College; Prof, of Chemistry in Penn'a College of Dental Surgery, Phila. 
 
 No. n. Pharmacy. Based upon " Remington's Text- Book of Pharmacy." By F. E. 
 STEWART, M.D., PH.G., Quiz-Master at Philadelphia College of Pharmacy. Second Ed. 
 
 Bound in Cloth, each $1.00. Interleaved, for the Addition of Notes, $1.25. 
 Bg^ These books are constantly revised to keep up -vith the latest teachings and discoveries. 
 
 P. BLAKISTON, SON & CO., 1012 Walnut Street, Philadelphia. 
 
NOW READY. 
 
 With Many Improvements for 1888. 
 
 37 th YEAR. 
 The Physician's Visiting List. 
 
 (LINDSAY & BLAKISTON'S.) 
 CONTENTS. 
 
 POSOLOGICAL TABLE, MEADOWS. 
 
 DISINFECTANTS AND DISINFECTING. 
 
 EXAMINATION OF URINE, DR. J. DALAND, based upon 
 
 Tyson's "Practical Examination of Urine." sth 
 
 Edition. 
 
 INCOMPATIBILITY, Prof. S. O. L. POTTER. 
 A NEW COMPLETE TABLE FOR CALCULATING THE 
 
 PERIOD OF UTERO-GESTATION. 
 
 SYLVESTER'S METHOD FOR ARTIFICIAL RESPIRATION. 
 DIAGRAM OF THE CHEST. 
 BLANK LEAVES, suitably ruled, for Visiting List , 
 
 Monthly Memoranda; Addresses of Patients and 
 
 others ; Addresses of Nurses, their references, etc. ; 
 
 Accounts asked for ; Memoranda of Wants ; Obstet- 
 
 ric and Vaccination Engagements ; Record of Births 
 
 and Deaths ' Cash Account > etc - 
 
 A NUMBER OF IMPROVEMENTS and additions have been made to the 
 reading matter in the first part. This has been done, however, without increasing 
 the number of pages. Great care has been taken in selecting the leather for the 
 covers and in each detail of manufacture. 
 
 SIZES AND PRICES. 
 
 ALMANAC FOR 1888 and 1889. 
 
 TABLE OF SIGNS to be used in keeping accounts. 
 
 MARSHALL HALL'S READY METHOD IN ASPHYXIA. 
 
 POISONS AND ANTIDOTES. 
 
 THE METRIC OR FRENCH DECIMAL SYSTEM OF 
 WEIGHTS AND MEASURES. 
 
 DOSE TABLE, revised and rewritten for 1888, by Ho- 
 BART AMORY HARE, M. ., Demonstrator of Thera- 
 peutics, University of Pennsylvania. 
 
 LIST OF NEW REMEDIES for 1888, by same author. 
 
 AIDS TO DIAGNOSIS AND TREATMENT OF DISEASES OF 
 THK EYE, DR. L. WEBSTER Fox, Clinical Asst. Eye 
 Dept. Jefferson Medical College Hospital, and G. 
 M. GOULD. 
 
 DIAGRAM SHOWING ERUPTION OF MILK TEETH, DR. 
 , Prof, of Diseases of Children, Univer- 
 
 For 25 Patients weekly. 
 50 
 
 75 " 
 
 100 
 50 " " 2 Vols. 
 
 ioo " " 2 Vols. 
 
 Tucks, pockets and Pencil, #1.00 
 
 1.25 
 
 " " 1.50 
 
 " " " 2.00 
 
 For 25 Patients weekly. 
 
 50 " ,VoU. 
 
 an. to June j tl 
 
 uly to Dec. J 
 
 an. to June ) ti tt t: 
 
 uly to Dec. J 
 
 INTERLEAVED EDITION. 
 
 Interleaved, tucks and Pencil, 
 
 2.50 
 3.00 
 
 1.25 
 3- 
 
 PERPETUAL EDITION, without Dates. 
 
 be commenced at any time, and used until full. Similar in style, con- 
 
 tents and arrangement to the regular edition. 
 
 No. 1. Containing space for over 1300 names, with blank page opposite each 
 
 Visiting List page. Bound in Red Leather cover, with Pocket and Pencil, $1.25 
 
 No. 2. Containing space for 2600 names, with blank page opposite each 
 
 Visiting List page. Bound like No. I, with Pocket and Pencil, . . . . 1.50 
 These lists, without dates, are particularly useful to young physicians unable to 
 
 estimate the number of patients they may have during the first years of Practice, and 
 
 to physicians in localities where epidemics occur frequently. 
 
 " For completeness, compactness, and simplicity of arrangement it is excelled fc y none ; n the market." N. Y. 
 Medical Record. 
 
 " The book is convenient in form, not too bulky, and in every respect the very best Visiting List published." 
 C "?ii a M ' di ? a t and Surgical Journal. 
 
 After all the trials made, there are none superior to it." Gaillard's Medical Journal . 
 ' t It has become Standard." Southern Clinic. 
 
 ' t Regular as the seasons comes this old favorite." Michigan Medical News. 
 ^ It is quite convenient for the pocket, and possesses every desirable quality." Medical Herald. 
 ' w C m St PP ular Visiting List extant." Buffalo Medical and Surgical Journal. . 
 
 We have used it for years, and do not hesitate to pronounce it equal, if not superior, to any." Southern Cltntc.^ 
 ' This Visiting List is too well known to require either description or commendation from us." Cincinnati 
 Medical News. 
 
 P. BLAKISTON, SON & CO., Publishers, 1012 Walnut Street, Philadelphia. 
 fg^* Large Stock of Physicians Ledgers of Various 
 
I \66 
 
 University of California Medical School Library