^mm ill ii!l!l slliil .;»n»HM»n.w»»».r, \ MANUAL PATHOLOGY INCLUDING BACTERIOLOGY, THE TECHNIC OH POSTMORTEMS, AND METHODS OF PATHOLOGIC RESEARCH W. M. LATE COPLIX, M.D. PROFESSOR OF PATHOLOGY ANU BACTERIOLOC.Y, JKFFKRSON MEDICAL COLLEGE. PHILADELPHIA : PATHOWHJIST TO JEFFERSON MEDICAL COLLEGE HOSPITAL AND TO THE PHILADELPHIA (BLOCKLEV, HOSPITAL; DIRECTOR OP THE CLINICAL LABORATORIES OP THE JEFFERSON MEDICAL COLLEGE hospital; PATHOLOGIST TO THE FRIENDS* ASYLUM FOR THE INSANE, PRANKFOKD FOURTH EDITION, REWRITTEN AND ENLARGED lUitb Jfour 1bun&rcC» anD Winctv^fivc lllliunrntioni .WANV OF- VVHK.H Akl. OkK.INAl.. a n D Zen Colored |M a t c ^^ IIA P. BLAKISTON'S SON & CO. IOI2 WALNLT STREET 'p ^'■rr: ^(■J ^% t' Copyright, 1905, by P. Bi.akiston's Son & Co. WM. F. FELL COMPA^Y ElECTROTYPERS AND PRINTERS 1220-24 SANSOM STREET PHILADELPHIA, PA. TO W. W. KEEN, M.D. PROFESSOR OF THE PRINCIPLES OF SURCERV AND CLINICAL SCRCERV IN THE JEFFERSON MEDICAL COLLEGE, AS A TOKEN OF RESPECT AND GRATITUDE THIS VOLUME IS DEDICATED BY THE AUTHOR. PREFACE TO SECOND EDITION During the winter of 1894 and 1895, Messrs. P. Blakiston. Son & Co. published, in serial form, abstracts of the writer's lectures, entitled "Lectures on Pathology." At the close of the college session the fasci- culi were bound, and the resulting volume placed on the market. Very- much to the surprise of the publishers, as well as of the writer, the edition lasted less than nine months. It was exhausted at a time when the teaching of the college year precluded the revision which the matter so much needed. During the past six months the entire book has been re- vised, the larger part having b^en entirely rewritten. The first edition contained 250 pages and 51 illustrations; the present volume, in the face of every effort to condense without sacrificing accuracy, has reached 638 pages and contains 268 illustrations. The most difficult probl.m has been to keep the volume from assuming undesired dimensions. : now that the work is completed, the writer wishes to say, parent li cally, that a volume of twice the size could have been produced v probably less labor. Being practically a new book, there are, no doi typographic and grammatic errors. The writer acknowledges in ad\-.. his appreciation of any communication calling his attt-Titioii to s lapses. In the publication of the original fasciculi the writer w.is 1.. the aid of Professor Kyle and Dr. Bevan. Professor Kyle v n fasciculus on "Tumors," and Dr. Bevan the article on "Bacteriology." In the revision of the work both articles have been somewhat but the thoroughness of the original has not demanded any revision. There have been made some additions and a rearrangement of subjects, in order to secure greater conformity " " remamder ot the book. In the original, acknowledgment of th. '• was given with the fasciculi; it is now incorporated here. Practicallv. all the added illustrations appear lur itic nrst time in a work on pathologv in the English language. The source is credited with each cut. Of the original illustrations it is not the author's prov- ince to speak. Thev have been prepared in the writer's laboratory from specimens and slides of which the clinical and pathologic histoloi^y were fullv known. In this connection the writer wishes to acknowledge the invaluable assistance of Professor H. F. Harris, who personally super- xi Xll PREFACE TO SECOND EDITION. intended the execution of most of the original drawings. Miss E. G. Harding, artist, has, with great patience, made the original drawings, often redrawing an illustration a number of times before submitting it for approval. In conclusion, the writer wishes to submit the volume, not as a treatise or book of reference, but, as its title indicates, as a manual that he hopes may be useful in the laboratory, postmortem room, and in clinical diagnosis by the aid of the microscope. To attain as fully as possible the last-named aim, the chapters on the microscopic exami- nation of tissues, blood, and urine have been most fully illustrated. Thanking the profession for its kindly reception of the previous edition, this volum.e is respectfully submitted for consideration. PREFACE TO FOi;Kril HDH10N. In presenting to the profession and students of medicine the fourth edition of this work I wish gratefully to acknowledge the cordial recep- tion accorded the third edition. Although much larger than any pre- ceding revision, and twice reprinted, the book practically has been out of print for over one year. During that time I have occupied my spare moments in revising, rewriting, and rearranging the subject-matter. A number of the old illustrations have been replaced by new. and many original drawings have been added. My conviction that properly prepared figures are of the utmost im- portance in elucidating the subject under consideration remains un- changed; in accord with this view the number of illustrations has been increased from three hundred and thirty, to four hundred and ninety- five; practically all those added are original. The colored plates, which first appeared in the last edition, have been continued and the number increased by the addition of others illustrating the parasitology of malaria, and the blood-changes of leukemia. For both sets of addi- tional plates— five in all — I am indebted to Dr. John C. Da Costa. Jr.. who kindly placed at my disposal the superb illustrations from his br.ok on "Clinical Hematology." The chapter on postmortem examinations has been ri\is<(i an-i enlarged, and new methods have been introduced in the chapters on technic. Bacteriologic technic has been transferred to the Appendix, in which are also included brief practical summaries of the methods of microscopic examination of the urine, and also the sputum. The tech- nic of blood examination is fully but briefly reviewed in the chapter on blood, with which it properly belongs. Special technic has been dis- tributed throughout the book ; whenever it was necessary to adopt any specific means for demonstrating a reaction or for satisfactorily staining morbid products, the method has been given with the consideration of the materials to be treated. The chapters on immunity and on the pathology of infections have been entirely rewritten and more fully illus- trated. The relation of poisons to disease production is discussed with some detail, and the recent theories of intoxication, and cytolytic pro- cesses, bearing on problems in general pathology, have been deemed important and worthy of incorporation. A chapter on malt^"^^" '"^ vii vni PREFACE TO FOURTH EDITION. including teratogenesis, has been added. The new matter has increased the text by about one-third, but, by enlarging the size and diminishing the margins of the page, and by other expedients well known to the experienced publisher, it has been possible to secure a less bulky and, I believe, a more presentable volume. Extended experience has led to the belief that many readers desire more information than the scope of this work permits, and that often an inquirer after the truth wishes to study the literature of some sub- ject, too briefly considered in a text-book or manual. To meet this demand I have inserted, in the present edition, numerous references to original articles, usually selecting those papers to which a fuller biblio- graphy is appended. In no case are the references complete, or even exhaustive, but practically all are to recent communications; few only are to publications antedating the year 1900. Wherever possible I have given references to an article in German, another in French, and still another in English; occasionally acceptable articles in other languages are mentioned. As the literature available for most practitioners and students is largely in English, many of the references are to publications in that language. The chapter on diseases of the nervous system, originally written by Prof. H. F. Harris, has been fully revised and contains considerable new matter. Dr. Alfred Gordon, Instructor in Neuropathology in the Jefferson Medical College, has kindly loaned me a number of exception- ally good illustrations and made valuable suggestions in completing the revision of this part of the work. The labor incident to revision has been lessened — indeed revision at this time was rendered possible — by the cooperation and cordial assis- tance of a corps of fellow-workers who generously gave time and effort, particularly by relieving me of the onerous duties incident to supervision of a busy Clinical Laboratory. To these gentlemen — Dr. AUer G. Ellis and Dr. John Funke — I wish to make a most grateful acknowledgment of my indebtedness. Dr. Ellis revised the chapter on the blood. I am also under obligation to Dr. Randle C. Rosenberger for aid in the com- pilation of stain reactions and biologic peculiarities of the bacteria. Dr. Frederick J. Kalteyer has aided by kindly loaning specimens for illustrations. The table on the blood occupying pages 428 and 429 is largely the product of his energy. Mr. Clark Evans has prepared the index. Many of the new drawings are by Miss S. L. Clark, whose skill is at- tested by the results attained. The reproduction of the new illustra- tions, both colored and uncolored, has been trusted entirely to the pub- lishers, to whom the author is under many obligations for the careful execution of this most difficult task, and for other courtesies. PRKIACE TO KOURTII KDITlO.V. In conclusion the author wishes to state that tlie oigiM t i,\ im- im^.k has not been changed, and that the present echtion, although greatly enlarged, remains exactly what the author intended the previous editions to be: namely, "not a treatise or book of reference, but, as its title indicates, a manual that the author hopes may be useful in the labora- tory and postmortem room and in clinical diagnosis by the aid of the microscope. " \V. M. L. C. TABLE OF CONTENTS. PART I. TECHNIC. CIIAl'TER 1. PACE Postmortem Examinations 1-32 Description of Instruments Needed. — Arrangement of Postmortem Room. — Records of Postmortems. — External Examination of the Body. — Internal Examination of the Body. — Letulle's Method. — Bacteriologic Examination of Organs. — Restoration of the Body. — Preservation of Tissues. CHAPTER II. Histologic Methods 33~52 Fixation of Tissues and Fixing Agents. — Infiltration Methods and Section Cutting. — Staining and Mounting Sections. — The Micro- scope and Method of Using the Instrument. PART II.— GENERAL PATHOLOGY. Introdvction 55-57 CHAPTER I. Abnormal. Malposition. Malformatio.v 58-63 The Normal. — Abnormal. — Malpositions. — Malformations. — Terato- genesis. — Types of Malformations. CHAPTER II. Disease, 64-80 Organic Diseases. — Functional Diseases. — Nosology. — Acute Dis- ease. — Chronic Disease. — Pathogenesis. — Internal Causes. — Sex. — Race. — Idiosyncrasy. -7— Heredity. — External Causes. — Occu- pation. — Habits. — Starvation and Allied Conditions. — Ther- mal Causes. — Trauma. — Alterations in Atmospheric Pressure. — Electric Discharges. — Poisons and their Classification. — Exo- genous Poisons. — Endogenous Poisons. CHAPTER III. Bacteria as Causes of Disease .'*i <> ; General Considerations. — Reproduction of Bacteria. — Bacterial Pro- ducts. — Toxins. — Infection. — Subinfection. — Paths of Infec- tion. — Paths of Extension. CHAPTER IV. Bacteria as Causes of Disease {Continued). Immunity 94-»oS Forms of Immunity. — Natural Immunity. — Acquired Immunity. — Passive Immunity. — Local Immunity.— .Antitoxic Immunity. — Bacteriol\-tic Immunity. — Theories of Immunity. — Phagocyto- sis. — Opsonins. — Cellulohumeral Theory. — .Ehrlich's Side-chain Theory. — Agglutinins. — Precipitins. xiii XIV TABLE OF CONTENTS. PAGE CHAPTER V. Bacteria as Causes of Disease {Concluded). The Pathology of In- fections, 106-1S0 Diseases due to Micrococci. — Diseases due to Bacilli. — Diseases due to Spirilla. — Diseases due to Spirochaetse. CHAPTER VI. Animal Parasites as Causes of Disease, 181-214 Diseases due to Protozoa. — Diseases due to Vermes. — Diseases due to Arthropoda. CHAPTER VII. Hypertrophy. Hyperplasia. Metaplasia. Heteroplasia. Hypo- plasia. — Agenesis or Aplasia 215-223 CHAPTER VIII. Infiltrations and Degenerations 224-248 Fatty Infiltration. — Amyloid Infiltration. — Pigmentary Infiltration. - — Calcareous Infiltration. — Glycogen Infiltration. — Parenchy- matous Degeneration. — Fatty Degeneration. — Hydropic De- generation. — Colloid Degeneration. — Myxomatous Degenera- tion. — Hyaline Degeneration. — Corneous Degeneration. CHAPTER IX. Necrosis, 249-258 Liquefaction Necrosis. — Coagulation Necrosis. — Fat Necrosis. — Caseation. — Gangrene. CHAPTER X. Circulatory Disturbances 259-284 Anemia. — Hyperemia. — Hemorrhage. — Hemophilia. — Lymphorrha- gia. — Congestion. — Stasis.- — Edema. — Thrombosis.- — Embolism. — Infarction. CHAPTER XI. Inflammation and Repair, 285-307 CHAPTER XII. Tumors, 308-371 Neoplasms. — Cysts. — Teratomata. CHAPTER XIII. Temperature Changes. Fever 372-381 Hypothermia. — Pyrexia. — Intoxications. — Local Infections. — Bac- teremia. PART III.— SPECIAL PATHOLOGY. CHAPTER I. Blood,.... 385-430 Technic.^ — -General Pathology, Composition and Structure of the Blood. — Anemias. — Chlorosis.- — Pernicious Anemia. — Leukemia. — Pseudoleukemia. — Splenic Anemia. — Mycoses of the Blood. — Animal Parasites of the Blood. TABLE OF CONTENTS. XV CHAPTER II. '*"' Spleen. CliAl'TER III Lymph-nodes, 431-441 442-449 CHAPTER IV. Thymis Body . 450-451 CHAPTER V. Serous Membranes 452-481 CHAPTER VI. Vascular System . . 482-539 Heart. — Arteries. — Veins. — Lymph-vessels. CHAPTER VII. Mucous Me.mbraxes 540-563 CHAPTER VIII. Organs of Respiration 564-627 Nose. — Larynx and Trachea. — Bronchi. — Lungs. CHAPTER IX. Diseases of the Urinary Organs . . 62S-672 Kidney. — Bladder.— Crethra. CHAPTER X. Alimentary' Canal 673-736 Mouth. — Tonsils. — Pharynx. — Salivary Glands. — Esophagus. — Stomach. — Intestines. CHAPTER XI. Liver and Biliary Passages, . 737-766 CHAPTER XII. Pancreas . 767-774 CHAPTER XIII. Ductless Glands • 775-787 Thyroid and Parathyroids. — Suprarenals. CHAPTER XIV. Muscles • "88-797 CHAPTER XV. Bones and Joints ■ 798-832 CHAPTER XVI. Nervous System • 833-894 Meninges. — Cord. — Brain. — Peripheral Nerves. XVI TABLE OF CONTEXTS, PART IV (APPENDIX).— GENERAL LABORATORY TECHNIC. PAGE CHAPTER I. Bacteriologic Technic, 897-933 CHAPTER II. Microscopic Examination of Urine, 934-945 CHAPTER III. Technic of Sputum Examination, 946-948 Index. LIST OF ILLUSTRATIONS. COLORED PLATES. Plate pAor I. The Tertian Parasite (Da Costa) f acinic i86 II. The Quartan Parasite (Da Costa), facing i88 III. The Estivo-autuiTinal Parasite (Da Costa) facing 190 IV. Cut Surface of Spleen Showing Lardaceous Change, and lodin Reaction ("Atlas of Pathology," Sydenham Society) facing 230 V. Spleno-Medullary Leukemia (Da Costa), facing 424 VI. Lymphatic Leukemia (Da Costa) facing 426 VII. Lung, Croupous Pneumonia. State of Red Hepatization. (Fox's Atlas.) facing 600 VIII. Lung, Croupous Pneumonia. Stage of Gray Hepatization. (Moditied from Bollinger) facing 604 IX. Diseases of the Kidney ("Atlas of Pathology," Sydenham Society), ' facing 654 Fig. I. Kidney, Chronic Interstitial Nephritis. Fig. II. Part of Kidney, Subacute Parenchymatous Nephritis. From girl, six and a half years old; scarlet fever; death on the forty-seventh day. More advanced degenerative change than in hgure IV. Fig. III. Part of Kidney, Chronic Parenchymatous Nephritis. Fig. IV. Part of ;Kidney, Acute Parenchymatous Nei)hritis. From a boy, nine years old; scarlet fever; death on the twenty-second day of the disease. The initial stage of engorgement is no longer present. X. Tuberculosis of Bladder,. . . .facing 670 Fig. Pace 1. Complete Postmortem Case 2 2. Modified Virchow Postmortem Knife 3. Median Incision, showing Method of Opening the Abdominal Cavity (Letulle), 7 4. The Sternum, Costal Cartilages, and Articulation of the Clavicle, as Exposed after Turning Back the Soft Parts (modified from Virchow), . . 8 5. Costotome 9 6. Saw 10 7. Heart, Showing the Lines for Incisions in the Preliminary Examination and Final Section. Fully Exposing the Valves (after Virchow) 11 8. Heart Showing the Interior of the Right Ventricle and Pulmonary Artery (after Virchow 1 12 9. Heart with the Left Ventricle Laid Open, Showing the Aortic Cusps and the Ventricular Aspect of the Mitral Valve (after Virchow) 13 10. Scissors '4 1 1 . Grooved Director '5 12. Line of Incision through the Posterior Border of the Lung (Letulle) 16 13. Incision fcr Separating the Oral and Pharyngeal Structures from the Floor of the Mouth (Letulle) , • ^7 14. Long, Thin, Brain Knife, of Value for Incising Organs,. 18 Is. Entcrotome ^* XVIU LIST OF ILLUSTRATIONS. Fig. Page i6. Probes 19 17. Dissecting Forceps, 20 18. Mallet or Hammer 20 19. Heavy Line Indicating Course Taken by Saw-cut in So-called Under- taker's Method, 21 20. Circumferential Saw-cut, to be Preferred in all Medico-legal Cases 22 21. Wedge-shaped Calvaria Removed by the Line of Saw-cut Recommended, 23 22. Chisels, 24 23. Myelotome, 24 24. Scalpel with Blade Shaped Somewhat Like a Bistoury, 25 25. Double Saw for Sawing through the Laminae of Both Sides at Once, 26 26. Perineal Incision for Removing Anus, Bladder, etc., in the Male (Le- tulle) ■ ■ 27 27. Perineal Incision for Removing the Rectum, Anus, and Reproductive Organs of the Female (LetuUe), 28 28. Bone-cutting Forceps, 29 29. Postmortem Needles 3° 30. Metallic Table for Fixation and Paraflfin Infiltration, 35 31. Block for Mounting Tissue Infiltrated with Paraffin, 36 32. Properly Trimmed Block, 36 33. Method of Applying Paper to Block, 36 34. Block Showing Tissue in Position 37 35. Mounted Tissue Ready for Sectioning, 37 36. Naple's Paraffin Bath for Infiltrating Tissues in Paraffin, 38 37. Forceps Convenient for Handling Cover-glasses, Blocks of Tissues, and Sections, 38 38. Laboratory Microtome, 39 39. Small Microscopic Scissors 39 40. Ryder Microtome, 4° 41. Ranvier's Microtome, 4° 42. Minot Microtome 41 43. Drying Oven, 42 44. Needles and Brush Suitable for Handling Sections 43 45. Dish for Removing Paraffin and Corrosive Sublimate and for Dehy- drating, 44 46. Dropping Bottle with Barnes's Dropper, which Closes the Mouth of the Bottle Like a Rubber Stopper 46 47. Proper Size Labels for Labeling Microscopic Slides 46 48. Microscope Suitable for General Pathologic and Bacteriologic Work, .... 51 49. Pygopagus (Debierre, Simes' Translation), 62 50. Marks Produced by Lightning (Ziegler), 74 51. Propagation by Fission (Coplin and Bevan), 82 52. From Culture of Bacillus megatherium 8^ 53. Bacillus butyricus 86 54. Bacillus acidi lactici 86 55. Cells from Exiidate, Case of Empyema, 98 56. Diagram Illustrating Ehrlich's Views Concerning the Union between Toxin and Cell loi 57. Diagram Illustrating Ehrlich's Views Concerning the Union between Complement, Immune Body, and Cell in the Process of Cytolysis In- cluding Hemolysis and Bacteriolysis, • • • 102 58 and 59. Diagrams Illustrating Ehrlich's Views Concerning the Action of Anti-immune Body and Anti-complement in Preventing Cytoly- sis, Including Hemolysis and Bacteriolysis, 103 60. Diagram Illustrating the Nomenclature of Schizomycetes Based upon their Morphology (after Schenck), 107 6 1 . Gonococcus, 108 62. Diagram of the Diplococcus of Pneumonia, Illustrating Relation of Capsule to the Contained Germ (Coplin and Bevan) no 63. Sputum, Croupous Pneumonia, m 64. Micrococcus (Staphylococcus) pyogenes aureus (Coplin and Bevan), ... 113 65. Streptococcus of Erysipelas (Coplin and Bevan), iiS 66. Margin of Membrane from Tonsil, Case of Diphtheria 120 67. Bacillus^tetani. Pure Culture from^Wound, 121 LIST OP ILLUSTRATIONS. XIX Fig. Paci: 68. Bacillus anthracis in Blood of Rabbit 124 69. Bacillus of Symptomatic Anthrax Containing Spores (Coplin and Bevan) 1 26 70. Bacillus of Symptomatic Anthrax Between Muscle-fibers of Inoculated Guinea-pig 127 71. Bacillus of Influenza 127 72. Highly Magnified Portion of a Necrotic Lymph-node Showing Pest Bacilli 129 73. Section of Kidney Showing Malpighian Body Containing Pest Ba- cilli s 131 74. Bacillus of Soft Chancre 132 75. Koch-Weeks Bacillus (Hansell and Sweet) 133 76. Bacillus lacunatus (Hansell and Sweet) 133 77. Bacillus pyocyaneus, 134 78. Bacillus typhosus 139 79. Bacillus typhosus. Showing Flagella (Gould), 139 80. Spirillum cholera asiaticae; Pure Culture, 143 81. Bacillus tuberculosis, 145 82. Bacillus tuberculosis (von Jaksch), 146 83. Diagram of the Structure of a Tubercle; A Purely Theoretic Idea, Rarely Demonstrated (Gould) J 50 84. Acute Disseminated Tuberculosis of the Lung (Schmaus) 151 85. Bacillus leprae (Extracellular) 158 86. Bacillus of Rhinoscleroma 159 87. Bacillus mallei. Pure Culture 160 88. Aspergillus 163 89. Favus from a Mouse (Coplin and Bevan) 164 90. Microsporon furfur (Coplin and Bevan) 165 91. Oidium albicans (Thrush Fungus) (Coplin and Bevan) 166 92. Actinomyces (Ray Fungus) from Bovine Actinomj-cosis (Coplin and Bevan)', 166 93. Actinomvces, from Culture 167 94. Yeast Cells from Pure Culture, Budding Forms are Present 171 95. Spirochaeta Obermeieri (Spirillum of Relapsing Fever) (Coplin and Bevan) 172 96. Spirillum of Vincent and the Fusiform Bacillus; Other Organisms are also Present. (From a case reported bv Dr. Rosenberger) 173 97. Spirochaeta from a Case of Syphilis (McW'eeney), 174 98. Trypanosoma lewisi 183 99. Trypanosoma gambiense in Human Blood 184 100. Coccidium oviforme from the Human Liver (after Leuckart, — Gould),. 185 loi. Diagrammatic Representation of the Life Cycle of the Plasmodium .Malariae (modified and redrawn after Clarke), 188 102. Fasciola hepatica • • I93 103. Schistosoma haematobium, Male and Female, the Latter in the Canalis Gynaecophorus of the Former (after Leuckart, — Gould) 104 104. Taenia saginata (Gould) 196 105. Cephalic End of Taenia saginata 196 106. Head of Taenia solium. On the Right, Egg of Taenia soHum (Gould),. . . 197 107. Cysticercus cellulosae. Completion of Head Formation (after Leuckart, — Coplin and Bevan), 107 loS. Hymenolepis diminuta '9* 109. Tc-enia echinococcus (after Leuckart, — CopUn and Bevan) 198 1 10. Hydatid Cyst, showing Daughter Cysts i99 111. Echinococcus. A Group of Scolices (from Dr. Loux's Case) 200 H2. Echinococcus. Scolex (from Dr. Loux's Case) -joo 113. Echinococcus Hooklets (from Dr. Loux's Case) 201 114. Dibothriocephalus latus (after Leuckart, — Gould) aoi 115. Free-swimming Embryo of the Dibothriocephalus latus (after Leuckart. —Gould) ' 201 116. Club-shaped Head of the Dibothriocephalus latus (after Leuckart. — Gould) 30I 117. Ascaris lumbricoides and Eggs (Coplin and Bevan), 20a 118. Oxvuris vermicularis (Coplin and Bevan) 203 119. Male Tricocephalus, Trichiurus or Whipworm 203 XX LIST OF ILLUSTRATIONS. Fig. Page 120. Trichina spiralis (after Leuckart), 205 121. Cephalic Extremity of Uncinaria Duodenalis ("Old-world Hook- worm"), Profile and Front View (after Leuckart, — Gould) 205 122. Duodenum showing Attached Uncinarite 206 123. Filaria Embryo (from F. P. Henry's Case) 207 124. Section of Head of Mosquito showing Filaria in Position to be Inocu- lated during the Act of Biting (from Howard, after Manson) 209 125. Elephantiasis of the Scrotum 210 126. Dracontiasis, or Guinea-worm Disease, 211 127. Acarus scabiei, 212 128. Scabies 212 129. Pediculus pubis 213 X30. Hypertrophy of the Mamm^ (Debierre, Simes' translation), 216 131. Liver, Showing Cirrhosis with Advanced Fatty Infiltration 225 132. Heart, Extreme Fatty Infiltration, 226 133. Pseudohypertrophic Muscular Paralysis; Fatty Infiltration of Muscle (Fltxtterer) 227 134. Universal Lipomatosis, 227 135. Liver, Showing Fairly Advanced Lardaceous Disease; the Organ Weighed 1 7 Pounds, 228 136. Section of Lung Showing Infiltration of the Connective Tissue of the Alveolar Wall by Coal-dust (Anthracosis) (Rindfieisch), 232 137. Section of a Lung Showing Chalicosis 233 138. Cloudy Swelling of the Epithelial Lining of the Kidney Tubule (Flat- terer), 242 139. Granular Degeneration of a Muscle-Fiber, Last Stage, Nearly Fatty (Schmaus) 242 140. Cloudy Swelling of the Liver Cells (Schmaus) 242 141. Kidney, Early Stage of Fatty Degeneration of the Epithelium of the Convoluted Tubes; from a Case of Pernicious Anemia, 243 142. Heart, Transverse and Oblique Sections of Muscle-fibers, Showing Fatty Degeneration, • 244 143. Intercostal Muscle, Transverse Section, from a Case of Epipneumonic Pluerisy, Showing Area of Coagulation Necrosis 251 144. Fat Necrosis Accompanying Acute Hemorrhagic Pancreatitis 253 145. Confluence of Two Tubercles. Section of Lung 255 146. Termination of Aorta, the Common Iliac, External and Internal Iliacs, Case of Thrombo-arteritis Due to Parauterine Inflammation and Ex- tension to the Vessels from Adjacent Tissues, 274 147. Section Through a Part of a Vein with its Contained Organizing Throm- bus (Schmaus) 275 148. Transverse Section of a Thrombosed Blood-vessel in Which Organi- zation and Canalization of the Thrombus Are in Progress, 276 149. Branch of Pulmonary Artery Containing Sarcoma Cells from a Case of Wide-spread Dissemination of a Tumor Primary in the Subcutaneous Tissue of the Thigh 278 150. Scheme Illustrating the Formation of an Anemic Infarct by Obstruc- tion of a Terminal Artery (Chantemesse and Podwyssotsky), 2 So 151. Scheme Illustrating the Formation of a Hemorrhagic Infarct as a Re- sult of Obstruction in a Terminal Artery (Chantemesse and Pod- wyssotsky), _. 281 152. Part of Spleen the Seat of Multiple Infarcts, 282 153. Kidney, Multiple Anemic Infarcts, 282 154. Lung, Hemorrhagic Infarct (Natural Size), 283 155. Leukocytes of a Frog (Stohr), 289 156. Polymorphonuclear Leukocytes from Center of Infiltrated Area in a Section of the Cerebral Cortex and Meninges from a Case of Suppura- tive Meningitis 290 157. Mononuclear Cells from Meninges in a Case of Meningitis, 290 158. Kidney, Chronic Interstitial Nephritis 297 159. Karyo'kinetic Figures Observed in the Epithelium of the Mouth Cavity of a Salamander (Stohr), 301 160. Cellular Elements of Formative Tissue (Schmaus) 302 LIST OF ILLUSTRATIONS. Xxi F'G. Paoe It) I. Granulation Tissue. Later Stage in Organization than Fig. 160 (Schmaus) ^04 162. The Formation of Capillaries in Embryonic Tissue (Landois) 305 163. Section Through the Border of a Healing Wound (Diagrammatic) (Rindtieisch) ^oO 164. Small Intestine, \ i j 165. Papilloma (Gould), 31O 166. Papilloma with Tendency toward Villous Formation (Schmaus), 317 167 Adenoma of the Cervix Uteri 319 1 68. Fusiform Myxoneuroma of the External Popliteal Nerve, 321 169. Glioma (Gould), 321 170. Scirrhous Carcinoma of Mamma 323 171. Squamous Epithelioma (Gould) 326 172. Section of Squamous Epithelioma (Rindfleisch) 326 173. Cylindric-cell Cancer of the Stomach 327 174. Section of Cylindric-cell Carcinoma of the Liver, 328 175. Cylindric-cell Epithelioma of the Cervix Uteri 330 176. Part of Cutaneous Surface of Right Mamma, the Seat of a Centrally Placed, Primary Scirrhous Carcinoma and of a Secondary Nodule ". 332 177. Carcinoma of the Mamma; Axial Section through the Nipple in Line from Sternum to Axilla 333 178. Glandular Carcinoma of the Liver (Scirrhus) 334 179. Carcinoma Arising in a Mamma the Seat of Cystic Disease, 335 iSo. Encephaloid Carcinoma (Soft Cancer) (Gould) 336 iSi. Glandular Carcinoma in Which the Stroma Has Been Converted into Mucoid Tissue (Gould), 336 182. Colloid Cancer (Rindfleisch), 337 183 and 184. Diffuse Lipoma of Neck, 338 185. Lipoma (Gould), 339 186. Chondroma (Gould), 340 187. Soft Fibroma, 341 188. Neurofibromatosis (Pode), 342 189. Secti(3n (Longitudinal) of the Uterus, Showing Myxomatous Enlarge- ment ". 343 190. Leiomyoma (Gould), 344 191. Cavernous Hemangioma from the Wall of Bronchial Cyst 346 192. Myxoma, 348 193. Lung, Part of Serous Surface; Secondary Sarcoma, 349 194. Lung, Incised Surface of Part of One Lobe, Secondary Sarcoma,... 351 195. Round-cell Sarcoma (Rindfleisch), 352 196. Round-cell Sarcoma (Gould) 353 197. Round-cell Sarcoma of a Lymph-node (Gould) 353 198. Spindle-cell Sarcoma (Gould) 353 199. Sarcoma of the Mammary Gland; Tumor o£ Several Years' Duration; Patient Thirty-five Years of Age, 354 200. Sarcoma, Mixed-cell, with Calcihcation of Part of the Intercellular Matri.x; Osteosarcoma 355 201. Giant-cell Sarcoma, 355 202. Alveolar Sarcoma (Gould) 356 203. Melanotic Sarcoma Springing from the Subcutaneous or Possibly from the Periosteal Connective Tissues, 357 204. Alveolar Melanotic Sarcoma (Gould) 357 205. Cerebrum, Coronal Section, .Anterior Aspect; Superior Parietal Lobule and Posterior Part of Temporal Lobe 358 206. Mamma, Lymphangio-endothelioma 350 207. Mamma, Lymphangio-endothelioma, 360 208. Perithelioma of the Carotid Body "i'>i 209. Perithelioma of the Carotid Body i'->2 210. Teratoma, ^'^4 211. Teratoma of Testicle, .^'>5 212. Syncytioma, 3^5 213. Gowers' Hemoglobinometer. Improved Form; 390 214. Von Fleischl's Hemoglobinometer, 301 215. Oliver's Hemoglobinometer, '-•~>2 216. Dare's Hemoglobinometer, ,>m4 XXll LIST OF ILLUSTRATIONS. Fig. Page 217. Dare's Hemoglobinometer, Horizontal Section, 395 218. Thoma-Zeiss Hemocytometer, 399 219 Capillary Mixing Tube of the Thoma-Zeiss Apparatus (Jaksch), 400 220. Mixing Tube of Galli 401 221. Counting Chamber of the Thoma-Zeiss Hemocytometer (Landois) 401 222. Hematocrit Tube 403 223. Rotating Frame of the Hematocrit, 403 224. A Method of Filling the Centrifuge Tube, 404 225. Diagrammatic Representation of Various Forms and Sizes of Red Cells, 407 226. Types of Red Blood-cells; also Leukocytes (Landois) 408 227. Poikilocytes 408 228. Crenated Red Blood-corpuscles (Landois), 409 229. Diagrammatic Representation of Leukocytes 412 230. Spleen Consisting of Two Parts Joined by Fibrous Band, 433 231. Hodgkin's Disease 448 232. Heart Showing Villous Pericarditis; Ascending and Transverse Por- tion of Arch of Aorta, Showing Aneurysm with Contained Clot, and Ruptures into Pulmonary Artery and Pericardium 464 233. Vertical Section Through an Inflamed Serosa after the Formation of the Fibrinous Exudate (Schmaus), 465 234. Intercostal Muscle, 466 235. Intercostal Muscle, Case of Empyema, 466 236. Pericardium (over auricle); Acute Serofibrinous Pericarditis En- grafted on a Serosa the Site of Past Inflammations, 467 237. Section Through Margin of Adhesion between Parietal and Visceral Pleura 468 238. Intestine. Chronic Adhesive Peritonitis, 472 239. Lung. Chronic Interstitial Pneumonia, Bronchiectasis, Hyalosero- sitis, and a Terminal Catarrhal Pneumonia Due to Mixed Infection by the Tubercle Bacillus and Pneumococcus, 474 240. Acute Tuberculous Pericarditis, Vertical Section of Inflammatory Exu- date (Schmaus"), .*.... 477 241. Chronic, Adhesive, Indurative, and Caseous Tuberculous Mediastino- pericarditis. Heart and Adjacent Mediastinal Structures 478 242. Pectoral Heart 484 243 . Malformation of the Heart, 486 244. Heart Showing Absence of Anterior Portion of Auricular Septum 486 245. Heart, Great Vessels, and Lungs from a Case of Transposition of the Vascular Trunks, 487 246. Fatty Infiltration of the Heart and Partial Pericardial Adhesion 489 247. Fatty Degeneration of the Heart 492 248. Diagram Showing the Distribution of the Coronary Artery in a Case of Local Fibroid Myocarditis, 496 249. Arteriosclerotic Disease of the Coronary Artery Giving Rise to Pro- gressive Obliteration of its Lumen, 497 250. Chronic Myocarditis (Schmaus) 497 251. Heart, Elastic Myocarditis, 499 252. Heart, Elastic Myocarditis 500 253. Aortic Orifice Laid Open, Showing the Valve Leaflets, Acute Endocar- ditis (redrawn from Schmaus), 507 254. Acute Endocarditis of the Mitral Valve, Section at Contact Line (Rindfleisch), 508 255. Narrowed Mitral Orifice, Showing Results of Adhesions with Con- siderable Fibroid Thickening (Buttonhole Mitral) 509 256. Adjacent Aortic Cusps, Showing a Small Vegetation Developing Just Below the Point of an Old Adhesion, 511 257. Adherent and Thickened Valve Leaflets (Rindfleisch), 513 25S. Heart and Aorta of Rabbit, Adrenalin Atheroma, and Multiple Aneur- isms 521 259. Aorta, Opened, Showing Different Types of Atheroma 522 260. Obliterative Endarteritis 523 261. Coronary Artery, Showing Arterial Sclerosis, 526 262. xVrtery, Early Stage of Arteriosclerosis 527 1 LIST C)l- ILLUSTRATION'S. Xxiii Fio. lAi.r. 263. Artery, Arteriosclerosis ^3^ 264. Artery, Advanced Arteriosclerosis ^27 265. Thoracic Aneurysm qjo 266. Symmetric Aneurysm of the Abdominal Aorta 532 267. Varicose Veins of the Leg :^35 268. Section of the Lung, Pneumoconiosis (Rindfieisch) 543 269. Section of Lung showing Chalicosis (Schmaus) 544 270. Granular Degeneration (Cloudy Swelling) of the Liver Cells (Schmaus), . . 545 271. Fatty Defeneration of the Liver Cells (Schmaus) 545 272. Granular Degeneration of the Kidney Epithelium (Cloudy Swelling) (Schmaus) 545 273. Section of Wall of Bronchus, Chronic Bronchitis 549 274. Margin of Pseudomembrane from Tonsil, Case of Diphtheria,. . . , 551 275. Vertical Section through the Pseudomembrane and Part of the Wall of the Larynx in Pseudomembranous Laryngitis (Schmaus) 552 276. Fibrinous Cast from the Bronchi, Case of Croupous Pneumonia (Schmaus), 553 277. Hemorrhagic Colitis 555 278. Uterus, Case of Septic Endometritis with Extensive Necrosis of the Endometrium and Myometrium, due to Postpartum Infection 556 279. Uterus, Section from Specimen shown in Fig. 278 557 280. Vertical Section of Mucous Membrane, Showing Diphtheric or Gan- grenous Inflammation, from a Case of Dysentery (Schmaus) 558 281. Intestine, Chronic Secondary Tuberculosis; Irregular Ulcers the Floors of Which Present a Necrotic Surface 560 282. Margin of Tuberculous Ulcer of the Intestine, 561 283. Pseudomembranous Laryngitis and Tracheitis due to the Bacillus diphtherias, 570 284. Tuberculous Ulcer of the Mucous Membrane of the Trachea 571 285. Perichondritis, Necrosis, and Laryngeal Ulceration 572 286. Tracheal and Partial Laryngeal Stenosis Following Cicatrization of a Gumma 573 287. Trachea of Child (Age Eleven Years) Showing Carcinoma Extending through the Wall as an Irregular External Mass 574 288. Lung, including a Small Bronchus. Bronchitis and Beginning Lobu- lar or Bronchopneumonia 376 289. Chronic Caseous Bronchitis, TuVjerculous Bronchitis, Caseous Soften- ing of the Bronchial Wall, with Thickening of the Peribronchial Tissue. Peribronchitis Chronica (Schmaus) 577 290. Lung, Emphysema and Bronchiectasis 580 291. Lung, Hemorrhagic Infarct 586 292. Pulmonary Emphysema (Flutterer) ^gi 293. Lung, Emphysema 592 294. Part of Right Lung, Circumscribed Gangrene, 596 295. Sputum, Croupous Pneumonia 598 296. Three Alveoli Filled with Fibrinous Exudate. Croupous Pneumonia. Stage of Hepatization (Schmaus) 601 297. Croupous Pneumonia. Single Air-Vesicle in the Second Stage, with Slightly Contracted Exudate 602 298. Lung, Croupous Pneumonia, Organization of the Intravesicular Exu- date 604 299. Lung, Including a Small Bronchus. Bronchitis and Bronchopneu- monia 609 300. Two Alveoli and a Part of a Third from Lung in Catarrhal Pneu- monia 610 301. Lung, Chronic Interstitial Pneumonia, Bronchiectasis, Hyalosero- sitis, and a Terminal Catarrhal Pneumonia Resulting from Con- current Infection by the Tubercle Bacillus and Pneumococcus 613 302. Tuberculous Pneumonia, 615 303. Lung. Chronic Caseous and L'lceratin^ Tuberculosis of the Ajjex; Tuberculous Bronchitis, and a Miliary Tuberculosis 616 304. Tuberculosis of the Lung • . 6ig 305. Lung, Chronic Ulcerative Tuberculosis of Upper Lobe: Acute Mili- ary Tuberculosis as a Terminal Lesion Involving the Entire Organ: XXIV LIST OF ILLUSTRATIONS. Fig. Page Slight Interstitial (Fibroid) Pneumonia; Chronic Tuberculous Peribronchitis; Bronchiectasis; Acute Pseudomembranous Bron- chitis; Chronic Fibrohyalopleuritis, 621 306. Wall of a Tuberculous Cavity (Schmaus), 622 307. Branch of Pulmonary Artery Containing Sarcoma Cells from a Case of Wide-spread Dissemination of a Tumor Primary in the Subcu- taneous Tissue of the Thigh 625 308. Lung, Part of Serous Surface; Secondary Sarcoma 626 309. Lung, Incised Surface of Part of One Lobe, Secondary Sarcoma,... 627 310. Longitudinal Section of the Kidney (Tyson, after Henle), 62S 311. Diagram of Blood-supply to Kidney (Rindfleisch) 629 312. Solitary Kidney 630 313. Horseshoe Kidney 630 314. Persistent Fetal Kidney due to Anastomoses Between the Renal Artery and Vein 631 315. Kidney, Showing Granular and Fatty Degenerations of the Cortex, from a Case of Pernicious Anemia, 636 316. Cloudy Swelling of the Epithelium Lining a Kidney Tubule (Fliit- terer) 636 317. Kidney, Multiple Anemic Infarcts. Case of Ulcerative Endocar- ditis,' 638 318. Kidney, Acute Suppurative Interstitial Nephritis,... 642 319. Kidney, Acute, Nonsuppurative, Interstitial Nephritis, 646 320. Chronic Parenchymatous Nephritis, 650 321. Kidney, Showing Chronic Diffuse Nephritis, , 651 322. Kidney, Showing Chronic Interstitial Nephritis, 652 323. Kidney Showing Advanced Chronic Interstitial Nephritis 654 324. Kidney, Chronic Interstitial Nephritis 655 325. Kidney, Chronic Interstitial Nephritis 656 326. Kidney, Chronic Interstitial Nephritis and Lardaceous Disease 657 327. Tuberculous Pyelonephritis; 'Chronic Tuberculosis of the Kidney 661 328. Hypernephroma. (Case Reported by Dr. Keen) 662 329. Section of Hypernephroma, Showing Capsule, 663 330. Section of Hypernephroma, Showing Character of Cells 664 331. Hydronephrosis 664 332. Congenital Cystic Disease of the Kidney, 665 333. Kidney, Congenital Cystic Disease; Laid Open, 666 334. Congenital Cystic Disease of the Kidney, 667 335. Congenital Cystic Disease of the Kidney, 667 336. Congenital Cystic Disease of the Kidney; Part of Wall of a Larger Cyst 668 337. Loss of Tissue due to Noma, 677 338. Tongue, Pharynx, Epiglottis, etc., from Case of Ludwig's Angina due to the Pneumococcus, 680 339. Section from Right Parotid 687 340. Section of the Left Parotid under a Very Low Power, 688 341. Mixed Tumor of the Parotid Gland, 689 342. Squamous-Cell Carcinoma of the Esophagus; Polypoid Type, 694 343. Stomach; Hour-glass Contraction Secondary to Gastric Ulcer, 697 344. Stomach, Chronic Catarrhal Gastritis with Erosions, 700 345. Stomach, Chronic Catarrhal Gastritis with Erosions; Vertical Sec- tion Through an Erosion, 701 346. Perforated Peptic Ulcer of Stomach (Gastric Ulcer) 705 347. Stomach, Carcinoma of Pylorus, with Secondary Nodules in the Retro- gastric Glands; External Surface, 710 348. Stomach, Carcinoma of Pylorus, with Secondary Nodules in the Retro- gastric Glands, 710 349. Pyloric End of Stomach; Marked Stenosis of Pylorus due to Con- traction of Scirrhous Carcinoma 711 350. Intussusception at Ileocecal Valve, 716 351. Intussusception Diagram Intended to Show the Relation of the Several Parts in Fig. 350 7^7 352. Hemorrhagic Colitis (Harris) 723 353. Perforating Ulcer of Colon (Amebic Dysentery), 726 LIST or ILIA'STRATIONS. XXV 354. Amebic Dysentery in Puppy (Third to Fourth Day) (Harris), 727 355. Small Intestine. Typhoid Ulcer during the Early Part o£ Third Week of the Disease 728 356. Section through a Typhoid Ulcer, End of Second Week of the Dis- ease (Schmaus) 729 357. Section of the Intestinal Wall at the Edge of a Typhoid Ulcer, Be- ginning of Third Week of the Disease ' 730 358. Small Intestine; Secondary Tuberculosis; Multiple Tuberculous Ulcers 732 359. Tuberculous Ulcer (Schmaus), 733 360. Hyperplastic Tuberculosis of Small Intestine, 7^4 361. Liver, Advanced Red Atrophy ; 1 1 362. Liver, Cirrhosis and Marked Fatty Infiltration 7ti 363. Liver, Fairly Advanced Lardaceous Disease, 7 ; 364. Multiple Amebic Abscess of Liver, ; i 365. Liver, Wall of an Amebic Abscess 752 366. Superior Aspect of Liver, Showing Unusual Degree of Cirrhosis with "Hob-nailed " Surface 754 367. Atrophic Cirrhosis of the Liver, Advanced (Schmaus) 755 368. Under Surface of Liver Showing Results of Congenital Syphilis 759 369. Syphilitic Cirrhosis of the Liver (Schmaus) 760 370. Part of Left Lobe of the Liver, Showing Primary Cylindric-cell Carci- noma 762 371. Acute Pancreatitis with Fat -necrosis (Douglas),' 770 372. Fat-necrosis Accompanying Acute Hemorrhagic Pancreatitis 771 373. Pancreas Showing Increase of Fibrous Tissue. Chronic Interstitial Pancreatitis 772 374. Thyroid Gland, Absence of Isthmus (Marshall, courtesy of Dr. Richard- son), 776 375. Thyroid Gland. Large Pyramid, So-called Pyramidal Lobe (Marshall, courtesy of Dr. Richardson) 776 376. Thyroid Gland Showing Double Pyramid (Marshall, courtesy of Dr. Richardson) '. 777 377. Thyroid Gland, Absence of Isthmus with Pyramid on Left Side (Mar- shall, courtesy of Dr. Richardson) 777 3 78. Intrathoracic Goiter Developed from Ectopic Thyroid (Dittrich, courtesy of Dr. Richardson) 778 379. Cretin Aged Twenty-two Years (Wagner, courtesy of Dr. Richard- son), 7 7Q 380. Unusually Large Cystic Goiter 78 1 38 1. Goiter (Bilateral) Causing Compression of the Windpipe Producing the So-called "Bayonet-shaped" Trachea (Demme, courtesy of Dr. Richardson) 7S2 382. Exophthalmic Goiter, Basedow's Disease (Courtesy of Dr. Richard- son) ■ 783 383. Section of Cortex of Kidney Containing Ectopic Adrenal 784 384. Section of Ectopic Adrenal Beneath the Peritoneum and Intimately Attached to the Capsule of the Liver 785 385. Section Taken from the Gastrocnemius Muscle of a Child Suffering from Pseudohypertrophic Muscular Paralysis, 780 386. Progressive Muscular Dystrophy, Erb Type. 790 387. Intercostal Muscle, Acute, Nonsuppurative, Interstitial Myositis 792 38S. Myositis, Acute Diffuse Suppurative. Case of Ludwig's Angina 793 389. Intercostal Muscle roa 390. Ossifying Myositis 391. Ossifying Myositis 392. Section of Bone-marrow of Rabbit, Showing the Delicate Conncclivc- tissue Reticulum Containing the Different Elements of the Marrow (Schafer) " ' 393. Elements of Human Bone-marrow (Stdhr) 394. Achondroplasia (Comby, courtesy of Dr. Richards' >:. >di 395. Chronic Productive Osteoperiostitis • ^o>, 396. Acromegaly, >*07 397. Osteophytes on the Popliteal Aspect of the Lower End of the Femur 808 XXVI LIST OF ILLUSTRATIONS. Fig. Page 398. Osteomyelitis Involving the Tibia, and, to a Limited Extent, the Lower End of the Femur 813 399. Exterior of Femur, Showing Result of Chronic Osteitis Associated with Chronic Productive Periostitis 816 400. Femur. Longitudinal Section of Bone Shown in Fig. 399 816 401. Femur, Head and Neck; Beginning Tuberculosis, . 818 402. Fracture of the Femur, Showing Overlapping of the Fragments with Rotatory Displacement of the Lower Fragment, and Attempted Union in this Position 821 403. Ten-Day-Old Fracture (Schmaus), 821 404. Sarcoma, ]\Iixed-Cell, with Calcification of Part of the Intercellular Matrix; Osteosarcoma, 824 405. Craniorrhachischisis Totalis 842 406. Spina Bifida, 845 407. Section of Cerebral Cortex and Meninges from a Case of Suppurative Meningitis 852 408. Spinal Cord and Meninges, 855 409. Spinal Cord and Meninges, Dura Laid Open on Posterior Surface; Case of Epidemic Cerebrospinal Meningitis 855 410. Section of Human Brain Including Wall of Cerebral Abscess 869 411. Disseminated Sclerosis in Medulla, 874 412. Disseminated Sclerosis in Cord 874 413. Sarcoma of Brain, Gross Specimen, 876 414. Sarcoma of Brain, Microscopic Section 876 415. Endothelioma of Pituitary Body, 878 416. Secondary Degeneration of Posterior Column, 879 417. Spinal Cord, Areas of Sclerosis due to Pernicious Anemia, 880 418. Myelitis. Areas of Softening in the Cord 881 419. Spinal Cord Showing Posterior Sclerosis, 886 420. Nerve, Acute Interstitial Neuritis, 890 421. Longitudinal Section of Musculospiral Nerve; Alcoholic Multiple Neuritis, 891 422. Neuritis Due to Chronic Lead Intoxication (Gordon), 891 423. Chronic Interstitial Neuritis showing Degeneration in Some of the Nerve-fibers 892 424. Moist Chamber for Potato Culture 899 425. Instrument for Cutting Plugs of Potato for Potato Culture, 900 426. Agate-ware Water-bath, 900 427. Test-tube Basket, 903 428. Double-walled Hot-air Sterilizer 903 429. Diagram of Interior of Hot-air Sterilizer 903 430. Tube-filler, 904 431. Arnold Steam Sterilizer, 905 432. Autoclave or Digestor, 906 433. Blake Bottle for Plating, 907 434. Dish Devised by Petri, 907 435. Platinum Inoculating Needles Mounted on Glass Rods, 908 436. Method of Holding Tubes, Cotton and Platinum Wire while Inoculating Solid Media, 909 437. Apparatus for Counting Colonies (Pakes) 910 438. Hesse's Aeroscope, 911 439 and 440. Two Forms of Stewart's Cover-glass Forceps, 912 441. Kalteyer's Cover-glass Forceps, 913 442. Novy's Apparatus for Anaerobic Cultivation of Plates and Test- tubes, 917 443. Sternberg's Anaerobic Culture-tube, 917 444. Wright's Method for Anaerobic Cultivation in Liquid Media, 918 445. Drop-culture Slide, 919 446. Small Incubator Sufficiently Large for Individual Work, 922 447. Apparatus for Holding a Mouse or Rat for Inoculation, 924 448. Koch's Syringe for Hypodermic, Intraperitoneal and Other Injection Methods for Inoculating Animals, 925 449. Spatula for Searing Surface of Organs 925 450. Sternberg's Flask, 927 LIST OF ILLUSTRATIONS. XXvii Fig. P^q, 451. Kitasato's Filter 027 452. Bacillus typhosus; Widal Test, Negative Reaction 930 453. Bacillus typhosus; Widal Test. Positive Reaction 930 454. Bacillus typhosus; Widal's Test, Pseudo-reaction 931 455. Water Centrifuge 035 456. Conical Glass Suitable for Sedimentation of Urine 936 457. Centrifuge with Hematocrit Attachment 936 458. Phantom and Distorted Red Blood Cells Found in Urine 938 459. Blood Cells in Urine 938 460. Blood Cells in the Urine, Lymph Corpuscles, Leukocytes of Pus Cells and Crystals of Triple Phosphates 938 461. Epithelium from the Conducting Part of the Urinary Apparatus, Mostly from the Bladder, 938 462. Renal (?) Epithelium 938 463. Seminal Elements, Some of which may be found in Urine 939 464. Illustrating the Formation of Casts, 939 465. Epithelial Casts 939 466. Blood Cells and Blood Casts 940 467. Hyaline and Epithelial Casts, 940 468. Granular Casts 940 469. Leukocyte and Crystalline Casts 940 470. Crystals of Uric Acid. Fungi 940 471. Some Forms of Uric Acid, 941 472. Acid Ammonium Urate, 941 473. Hippuric Acid 941 474. Some Deposits in Acid Fermentation of Urine 941 475. Some Deposits from Ammoniacal Urine (Alkaline Fermentation) 941 476. Whetstone and Irregular Crystals of Uric Acid, 941 477. Ammonium Urate 941 478. Stellate and Feathery Crystals of "Triple Phosphate 943 479. Forms of Crystals of Ammonio-magnesium Phosphate 943 480. Ammonio-magnesium Phosphate 943 48 1 . Magnesium Phosphate, 943 482. Amorphous Granules of Calcium Carbonate 943 483. Oxalate of Lime 944 484. Amorphous Granules, Wedge-shaped Crystals, Some of which are Arranged in Rosettes, Calcium Phosphate 944 485. Dumb-bell and Octahedral Crystals of Calcium Oxalate 944 486. Calcium Sulphate 944 487. Cystin and Oxalate of Lime 944 488. Leucin and Tyrosin 945 489. Leucin and Tyrosin 945 490. Cystin 945 491. Cholesterin, 945 492. Indigo 945 493. Squamous Epithelium 046 494. Curschmann's Spirals, 047 495. Charcot-Leyden Crystals,.. 048 PART I. TECHNIC PART I.— TECHNIC. CHAPTER I. POSTMORTEM EXAMINATIONS.' I. INSTRUMENTS NEEDED. A postmortem may be made with a very few instruments; those supphed in an ordinary dissecting case may suffice for the examination unless the central nervous system is to be removed, in which case a saw will be found necessary. Scarcity of instruments is rarely a justifiable excuse for failure to avail one's self of an opportunity to hold a post- mortem. A most thorough examination may be made with a knife such as is ordinarily used by butchers, a saw, and a carpenter's hammer and chisel. The instruments and apphances given in the following list may be pro- cured by those who contemplate making postmortems, the extent of their purchase being largely a matter of taste and money available. The in- struments marked by an asterisk are considered indispensable, the others being conveniences to facilitate or lessen the labor: * One Virchow yjostmortem knife. * Two strong scalpels. * Two small scalpels; one probe-pointed. One costotome, or, when this can not be obtained, a cartilage knife or a saw may be substituted. * At least two dissecting forceps : one with corrugated Vilades and one with rat-toothed blades. A number of such instruments will be found useful. * One pair of scissors: one blade sharp and one probe-pointed. One enterotome, or. when this is not available, a small cork or piece of wood may be pushed over the tip of the sharper {minted blade of the ordinary scissors. Two' long probes: one should have an eye and one should be quite slender; the latter is convenient for tracing ducts. An instrument to be commended is a combined grooved director and probe. For the exami- nation of sinuses and whenever it can be employed, there is no instru- ment that can be used to better advantage than the trained finger. * One saw with a well-bellied cutting-edge. * One grooved director. ' The student wishing to add to the ff)lIo\vin}^' ci)itome of postmort. nic should consult "La Pratifjue des Autopsies." by Letulle. "Manuel • et pratique des autopsies," bv Zilgien. " Patholosji.'^ch-anatonusche Dia.u''— "• - bv Orth, "Sections-Technik," bv Xauwerck. Postmortem Patholog>-. ' by Cat- tell, and "Pathological Technique," by Mallon.' and Wright. The authr.r has in preparation a manual dealing with autopsy and laborator>- technic. 2 TECHNIC. * Two large postmortem needles. * Two spools of flaxed thread: one white, one black. * One mallet ; the rawhide mallet has the advantage of making but little noise when used on the chisel. The steel hammer ordinarily sup- plied with postmortem cases has a blunt hook on the handle, which is useful for removing the calvaria, and occasionally for other purposes. The objectionable noise made by pounding on a metalHc chisel may be overcome, at least partly, by covering the chisel with a folded towel. One chisel. Of the various forms of chisels recommended, the lower one in figure 22 will be found most useful. Some of the forms of hatchet- chisel, however, will be occasionally used. A brass or German-silver ruler, graduated in inches and in centi- meters, win be found useful. Such a ruler should be at least twenty centimeters in length, and the graduation throughout should be in tenths; a finer graduation on instruments of this kind can rarely be read at the postmortem table. As a result of attempts to reduce the number of instruments contained in the postmortem case, the writer Fig. I. — Complete Postmortem Case. It is convenient to have a leather covering for the case. has had the long, thin-bladed brain knife, shown in figure 14, graduated along its back. As the instrument is useful for incising organs, the graduation is convenient and always at hand. A double rachiotome is a very useful instrument, but is not, how- ever, convenient for carrying to private postmortems. A strong bone forceps will occasionally be needed. Measures of Capacity. — Small graduates measuring from o.i c.c. to 50 c.c. will be found useful. Larger measures should be at hand. Any agateware or tin vessel (the former is preferable) may be standardized by a smaller graduate, and being very much less fragile and less expen- sive, is therefore to be preferred. A syringe for sucking up fluid from the bottom of cavities not easily accessible is a convenience. Postmortem Room. — In well-appointed hospitals, morgues, etc., a room is usually set apart for postmortems. This room should be well lighted and capable of thorough ventilation. The floor should be of imper- meable concrete, the walls tiled or Ijuilt of enameled brick, or, in the POSTMORTEM EXAMINATIONS. 3 absence of these, covered by lusterless white enamel paint. A capacious postmortem table should be so placed in the room as to be well lighted and accessible on all sides. The size of the taljle is often a matter of individ- ual preference. The table preferred by the writer is three feet wide, six feet long, substantially constructed, zinc or slate covered, the covering sHghtlv raised at the edges of the table, and the top gently sloj)ing toward a large grate-covered drain in the center. This drain, thor- oughlv trapped, may be directly connected with the sewage pipes, and may be so attached to the ventilation system as to secure a strong downward draft, thus drawing downward all odors which would other- wise rise and permeate the room. For convenience in measurements a centimeter and inch scale may be ruled upon the edge of the table. Although never to be used when it can be avoided, an abundance of artificial light should be at command. The best artificial light for the postmortem room is afforded by Welsbach burners with porcelain reflector and shade or Nernst incandescent electric bulbs; thirty-two candle-power incandescent lamps with thoroughly frosted globes are objectionable substitutes for natural light. All forms of artificial light so modify the color of organs as often to afford misleading pictures to the uninitiated. Water-supply. — Suspended just above the autopsy taV)le and coming down to within an inch or so of the table should be a rubber hose con- nected with proper metallic fixtures, so arranged as to afford a mixing device, by means of which hot and cold water can be mixed and delivered through the rubber tube at any temperature that may be desired. B>' permitting the rubber tube to project practically to the table the end can be kept in a pan, thus affording a small reservoir of constantly clean water. The flexible rubber hose affords facilities for washing the table and cleaning the instruments and appliances. A capacious sink in some part of the room is desirable; into this should drain a slate dripping-slab sixty centimeters wide and two meters long. Two scales should be at command — one for weighing from a fraction of a gram to ten or twenty grams, the other for heavier masses. Al- though rarely at hand, a scale for weighing l)odies is desirable. Scales for weighing organs and tissues should have large brass pans that can be readily cleaned. A head block twelve inches long and six inches square, with a notched depression near the center for receiving the neck, will be found useful in supporting the head, and similar blocks may be used for arching the body during the examination of the spine and the removal of the cord. Heavy boards, fifty by sixty centimeters, will be found serviceable for the support of organs during section. A vise will be occasionallv needed. Of the various forms of head holders in the market, the writer has never felt that any was better than the hand. Every well-equipped postmortem room has a book for recording the data obtained at postmortems. This book is usually made up of printed sheets, having a heading arranged according to some definite form which has been adopted by the pathologist. Such headings are useful in making it reasonably certain that no matter who makes the postmortem, the customarv 'routine will be followed. The volume TECHNIC. should not contain a very large number of pages, certainly not over four or five hundred, as a large number would make it too bulky for con- venient handling; nor should the sheets be too large. The book to which the writer is accustomed has a page forty centimeters long by twenty-eight centimeters wide, and has printed on each alternate page the form given at the foot of this page. At the time the book is printed it is well to have two or three hundred sheets left unbound, so that at postmortems made outside the institution it will not be necessary to carry the book. II. PRELIMINARY DATA. Before beginning the postmortem it is desirable to know and record the name; age; residence, or, in hospital cases, the ward and bed; sex; color; date and hour of death; date and hour of postmortem ; methods of preservation if any have been used; the clinic diagnosis; the name and residence of the physician, if any, who last attended the case, and, if possible, his presence should be had at the postmortem. In medicolegal cases the body should be identified. If the time at which death took place is not known, it may be approximated by the postmortem evidences. III. THE POSTMORTEM. In order that the record of a postmortem may be perfect, it is ab- solutely necessary to follow a definite method in each case. If circum- APPROVED FORM OF POSTMORTEM BLANK. [N.A.ME OF Institution.] POSTMORTEM. Ward Register Xo Name, Age, and Sex of Patient Color Physician.or Surgeon Residence Resident Physician Birthplace Date and Hour of Death ' Date and Hotir of Postmortem Clinical \ Pathologic Diagnosis. Diagnosis. When possible, it is desirable that the following order of examination and recording the postmortem shall be followed : T. External examination: EWdence of injury. General nutrition. Ante- or postmortem mark IT Internal examination. I. .\bdominal Wall. S. Thymus; Thyroid. 14. Pancreas. 2. Peritoneum. 9. Spleen. 11;. Intestines. 3. Pleurte. 10. Adrenals and Kidnevs. 16. Esophagus. 4. Pericardium. 11. Bladder and Internal and Ex- 17. Vena Cava and Aorta 5. Heart. ternal Genitals. la. Head. 6. Lungs. 12. Stomach and Duodenum. 19. Spinal Cord. 7. Larynx; Trachea; Bronchi. 13. Liver. 20. Miscellaneous. POSTM ( ) KT E M K X A M I N A T I O \ S. stances demand a variation from this routine method, the reason for varyi)ti; slioiilJ constitute a part of the record. The following presents nothing original, and is the method adopted by the writer: (A) The Date and Hour of the Postmortem. (B) External Examination of the Body. (a) Is the body dead.' The following observations should be made and recorded as a part of the ]>ostmortem notes, as they cover not only the signs of death, but constitute a part of the evidence of diseased conditions: (i) Examine for evidence of respiration and circulation. (2) Look for opacity of the cornea, loss of sensibility in the conjunctiva, pupillarv reaction, which may, in doubtful cases, be tested by atropin or eserin; if the eves are sunken, with wrinkled tunics, the evidence is clear. (3) Pallor of the body may or may not be present, and while valuable as a sign of death, it may be found in the living during swooning, the algid state of ague, collapse, etc. (4) Cooling of the l)ody to the tem- perature of the surrounding medium {cils^or mortis) occurs in from fifteen to twentv-four hours. The bodies of children and old and lean bodies cool quite rapidly, while bodies of fat. young, and middle-aged in- dividuals retain the heat much longer, the bodies of persons dying from suffocation, electricity, tetanus, and yellow fever very slowly yield their heat. (5) Cadaveric rigidity, or rigor mortis, occurs at a varying interval after death. It may become manifest but a few minutes after death, or it may be delayed eighteen or twenty hours; usually, it develops simultaneously with the loss of body heat. The duration of rigor mortis is extremely variable, lasting in some instances but a few moments; in other cases, hours, days, or even weeks. (6) Cadaveric lividitv (the cadaveric blotches called livores mortis) and siiggillation are terms applied to the livid or violet-colored discoloration which is seen usuallv several hours after death. It ]:)ecomes apparent in the most dependent portion of the body, and is the result of blood gravitating into the capillaries. ( 7 ) Piitrcjacti'on is an indubitable sign of death. The time at \vhich it becomes manifest varies greatly, and is dependent upon the condition of the bod v. the surrounding media, and the cause of death. (8) Experimentallv. 'we may infer that the body before us is dead V)y injecting ammonia water under the skin; in death such a procedure leaves no mark, but in simulated death it occasions a deep red or pun)le spot. A dead body can not be blistered. Brissemoret and Ambard state that aciditv of the tissues is an indubitable sign of death. Icard suggests the subcutaneous injection of 0.5 gm. of fluorescein which, if life be present, rapidlv stains the skin, eyes, mouth, urine, and saliva. The iodids may be similarly used in the saliva or urine exammed for iodine. {b) General Considerations.— The amount of adipose tissue, the muscular development, and the nutrition of the body should be carefully noted, and the record completed or verified as the internal examination proceeds. In case the body has not been identified an elaborate des • tion should be made for the purpose of further identification : the hi-, weight, measurement of chest, limbs, hands, and feet, color of eyes and hair should be noted, and of the last some should be preserved. A careful survev of the mouth as to dental peculiarities, absence ot teeth filled or irregular teeth, or, better, a dental impression taken in w^ax or plaster, should be made. If false teeth are present, they 6 TECHNIC. should be removed as possible aids to future identification. Abnor- malities, malformations, marks of any kind, should be noted, and, when possible, a photograph of the nude body should be obtained. Such data may, with perfect propriety, constitute a part of any post- mortem record; indeed, they are desirable although rarely incorporated in the protocol. Except in the cases mentioned they might have little value in any given postmortem, but in the compilation of important data based of necessity on a large number of cases — e. g., the size and weight of organs as compared with the height and weight of the individ- ual — such records would become invaluable. (c) Evidence of Violence or Disease. — Ecchynwses should be carefully described as to size, shape, and position. This form of discoloration may be distinguished from sitggillaiion in that it does not disappear on pressure, and if an incision be made into it, bloody fluid will escape, or a clot may be discovered in the subcutaneous tissue. All abrasions, eruptions, bed-sores, ulcers, cicatrices, wounds, edema, pigmentations in the skin and mucous membranes must be accurately described, and their positions carefully recorded. Fractures and dislocations must be closely observed, and their character and the parts involved described. The external orifices of the body should be examined, and their condition and contents noted — e. g., mouth and nose for foreign bodies, evidences of corrosive poisoning, etc.; in the female, the breasts, abdomen, and Fig. 2. — Modified Virchow Postmortem Knife. Twenty-four centimeters long, of which 9.5 cm. is cutting-edge. external genitals should be examined for evidences of disease, violence, or physiologic processes, such as menstruation, recent delivery, or evidences of past gestation, as shown by the mammae, abdomen (linea albicantes), or external genitals ; in the male look for evidence of malfor- mation of the sexual organs or venereal disease, also seminal stains. Examine the anus for fissures, inflammation, fistulae, morbid growths, cicatrices, etc. Examine the hernial outlets for evidences of rupture. If the body is that of an infant, examine the fontanels and sutures, and note the various diameters of the skull. Measure the body and examine the umbilical cord. In the male the scrotum should be examined to de- termine if the testicles have descended; note, also, the presence or absence of vernix caseosa. Carefully examine the epiphyses, and especially that of the lower extremity of the femur. (C) Internal Examination of the Body. The large Virchow knife is used for most of the incisions ; it is grasped firmly in the hand by the thumb, middle, ring-, and little fingers, while the index-finger rests upon, or at the side of, the blade. Cuts are made with a drawing movement, the shoulder- and elbow-joints acting as centers, the wrist and fingers rigid. Pushing the knife through a tissue or organ, as one would a chisel, is to be avoided, and equally objection- able are sawing and hacking. In ordinary dissection a scalpel is held like a pen, motion being at the joints of the fingers and wrist — a process POSTMOkTH.M EXAMIXATIONS. 7 entirely too tiresome and slow for postmortem work except when very delicate dissections are to be made. The body rests firmly upon the back, and the operator, if right- handed, stands to the right of the cadaver. To expose the abdominal and thoracic cavities, an incision shoidd be carried from the lower border of the thyroid cartilage, or from the interclavicular notch, to the sym- physis pubis, making a sharp semicircular turn to the left at the umbilicus in order to avoid injury to the remains of fetal organs at that j)oint. The point in the neck at which to begin the incision will be determined by circumstances over which the operator commonly has no control. If he can select the starting-point of his incision, he will ordinarily begin just under the chin, or may even make a Y-shaped cut extending to the angle of the jaw on either side; this permits a most careful examination of the floor of the mouth, pharynx, larynx, and adjacent structures. So extensive a dissection is rarely permissil)le; in most instances the loosened skin can be retracted upward in such a manner as to permit the J- - ISION, SHOUI.. . . ..;,..,„ ;iii, .VuKuUlNAI. Cavity. — {LttulU.) Ordinarily it is not possible to extend the incision to the chin, in which case it docs not go beyond the interclavicular notch. removal of the tongue when the vertical incision does not rise above the level of the thyroid cartilage. Still, as before stated, circumstances, more commonly than any arbitrary rule, will settle this point. Over the abdomen, the first incision should pass through the skin and subcutaneous tissue; then carefully cut through the abdominal wall immediately below the ensiform cartilage; insert two fingers of the left hand, drawing the abdominal wall upward; continue the incision, the fingers being used as a guide to the knife. A most excellent rule, never to be forgotten by the beginner, is to always keep the point of the knife in view, or, if this is not possible, it should be guanled. If the novice makes it a rule never to cut anything until he has identified it and de- termined what are its relations, using touch possibly more than sight to establish these facts, he will often be astonished at the dexterity which he quickly acquires and the rapidity with which his senses become trained to recognize the tissues before him'. Note the amount and color of the subcutaneous fat in the al)dominal wall, its consistency, and 8 TECHNIC. the presence or absence of edema. Examine the muscles for pallor, hyaline spots, degenerative changes (such as occur in typhoid fever), and small white ovoid bodies, encysted trichinae. Dissect the tissue from the chest-walls as far back as the junction of the costal cartilages with the ribs; then make strong traction on the abdominal walls to break up the rigor mortis. After breaking up the rigor mortis the Fig. 4. — The Sternum, Costal Cartilages, and Articulation of the Clavicle, as Exposed after Turn- ing Back the Soft Parts. — (Modified from Virchow.) On the left is shown the line of incisions made through the cartilages from below upward, if a costotome is used; from above downward, if a knife or saw is employed; and also the incision necessary for disarticulating the cla^^cle. When it is not desirable to disarticulate the cla\-icle, the manubrium is separated from the gladiolus at point A, the incision being made from behind. muscles can be further incised, and examined for evidences of bruises, inflammation, and suppuration, and suspicious portions removed for microscopic study. In the Paris Morgue' the incision used begins immediately beneath * Paris letter in the "Boston Medical and Surgical Journal," May 19, 482. 1S98, POSTMOUTKM KXAMINATIDNS. () the chin, jiasscs over the larynx and trachea, sweeps across nearly to the left anterior axillary line, which is followed to the crest of the pelvis. is carried alontj the up])er anterior border of the j^elvis to the ri^ht anterior axillary line, thence to the anterior margin of the ri^'ht axilla, and finally to the startin<;^-point. In the i)resence of sj)ecial conditions such an incision might be advanta.c;cous; in most instances it is clearly unnecessary. Abdominal Cavity. — First note the relative position and color of the Hver. stomach, and intestines; and also the relations of the viscera to the costal and ensiform cartilages. The examination of the cavity is not of the organs individually, Imt of their relation to one another and to the walls; also examine the serous membrane— the peritoneum. A careful search should be made for adhesions and other evidences of inflammation, recent or old, and for thickening and opacity of the serous membrane. The amount and character of anv fluid in the cavity must be noted, and, if in excess or otherwise abnormal, the source or cause of the morbid condition must be sought. The color of the Hver should be observed before those changes incident to the oxidation of the blood occur. Search carefully for perforations of FiC. S. — COSTOTOME. the bowel, stomach, bladder, or gall-bladder, whenever the fluid in the cavity is abnormal. Note accurately the position of the diaphragm, ordinarily, on the right side it ascends as high as the fourth rib or inter- space; and on the left, to the fifth rib. Remove any fluid present in the cavity before opening the thorax, otherwise fluids in the abdomen flow into the thoracic cavity and thereby complicate the examination. In infants the umbilicus must be examined carefully; the attached cord or part of the cord and the fetal vessels should be closely inspected and fully descrilied; so far as i)Ossil)Ie. the vessels should be examined for evidences of infection, throml)Osis, ami obliteration. Thoracic Cavity. — In the new-born when it is imi)ortant to determine if resjnration had been established or if air had entered the lung it is well to ligate the trachea as soon as the first incision is made and before op>ening the abdominal cavity; such precaution prevents air from being drawn into the lungs by traction on the diaphragm or raising the breastplate. With a heavy knife, or costotome (or. in tlv ' e of the latter, when the cartilages are calcareous, a saw may be u r the costal cartilages close to the ribs, care being exercised not lu i:ijure lO TECHNIC. the tissues beneath. If the costotome is used, the blade inserted be- neath the cartilage should be made to hug that structure closely; if a knife or saw takes the place of the costotome, the incision through the cartilages should begin above, and before one cartilage is completely severed, the blade or shank of the instrument should be made to rest on the next cartilage, thus preventing sudden thrusts which may wound underlying structures. When the last cartilage is reached, it should be gently raised by the unoccupied hand, at the same time depressing the underlying structure, thereby avoiding the danger of wounding the latter. Divide the attachment of the diaphragm, raise the sternum, and dissect off the attached tissue, taking care to direct the edge of the knife toward the bone in order to avoid injury to the pericardium or other intrathoracic tissues. Cut the ligaments binding the clavicle to the sternum, divide the sternal attachment of the sternocleidomastoid muscle, and pull the breastplate to one side. In a cadaver in which the section of the thorax has been made as just directed, the shoulders, having lost the support of the clavicle through their sternal attachment, collapse together, making the chest appear very much distorted. To avoid this, in cases where the body is to be viewed, the manubrium and gladiolus may be disjointed by drawing the edge of the knife across the under surface of the articulation of the manubrium and gladiolus (see Fig. 4, p. 25) and raising the lower segment of the sternum. Fig. 6.— Saw. A large firm handle is wanted, with good pistol grip. Examine the pleurse for evidences of inflammation, either remote or recent; note presence or absence of fluid, also its quantity and char- acter, as in the peritoneum. Fluid in each pleura should be removed, so as to prevent its flowing into the pericardium; or, in case the peri- cardium contains much fluid and any escape into the pleura, its quantity may be accurately estimated. The fluid in each cavity should be measured, and the quantity made a part of the record. Adhesions should be looked for and described. The mediastinal tissues, the re- lation of cysts, new growths, and aneurysms to adjacent viscera, and also the thymus may now be investigated. The last-named structure atrophies in childhood, but in infancy is an organ that should always be examined. The pericardium should now be opened by an incision extending from base to apex in a line parallel to the long axis of the heart. In opening the pericardium the writer has seen the heart in- jured so often that he desires to insert a word of caution and give a little more detailed method for preventing this accident. The peri- cardium is picked up in a fold either by the index- and fore-finger of the left hand or by the use of "rat-toothed" forceps; b}^ gentle trac- tion this fold of the pericardium can be raised to a distance of 2.5 cm. The back of the knife is now placed against the heart and the fold, 1 • ( » S T .\ K) K r !• M i: X A M I N A T I O N S . I I made as previously directed, is iranslixcd and the opening' completed by cutting from within outward. A similar incision lias been long recommended by surgeons while operating upon hernia where wound- ing the imderlying tissue may be attended liy calamitous conse(}uences, and if applied to the pericardium with Ijut slight precaution, wound- ing of the heart may be entirely avoided. From this incision, which is two or three centimeters in length, the incision in the long'^axis of the heart, as previously directed, may be readily made. Incisions at Fic. 7.— Heart SHOwnxc. the Lines for Inosions in the Preliminary Examination and Final Section. Fully Exposing the Valvk. — (A/trr \'inho-u.) A. Pulmonary artery. B. .Aorta. C. Right auricle. The incision .V to iV is th.it adrised by Virchow. The one preferred by the writer is from K to /, for ihe preliminar)- opening . f tlir rikilit vintrii 1<-. Th. firrliminarf operiinK of the right auricle is made at C. The prflimin.-iry open: 'h.- prclimin;ir>' opening of ihi- left ventricle is m.vlc at F to E. .■\lter it C is carried out through ihc vena, cava; ihr in. i-i.n fr.:;! K '<• I ^ « twecn the letters .U an^i .!. and l>eIo\v is ■ ir incision F to £. in the lift ventricle, is aorta at L. From the lower [xinion. at / this permits the flap to be turned back so lii be carried through the mitral orifice. 1 1-1. .n iii.ili- r.i.iy (den right angles to writer does not cision than that the great vessels, of inflammation, the great blood- character. The Heart. — Xote the condition of contraction or relaxation of the the long incision are rarely, if ever, demanded; the recall an instance in which he has needed a larger in- aflforded by the opening extending from the apex to Examine the layers of the jjericardium for evidences and look carefully for adhesions, particularly about l-vessels. Measure the pericardial fluid and note its 12 TECHNIC. heart's wall; open the heart in situ; raise the organ by its apex, pass the fingers of the left hand under the organ, and so grasp it that the thumb and first finger will close the auriculoventricular orifice of the right side, and then make an incision into the auricle between the venas cavas. Examine and note character of contents; without re- laxing the grasp on the auriculoventricular orifice, open the right ven- tricle by an incision in line with the pulmonary artery and close to the ventricular septum; insert the index-finger of the right hand and examine the contents. The left heart is opened by grasping it as in opening the right. The auricle is incised near the appendix and im- mediately above the auriculoventricular septum, and its contents are noted. The left ventricle is opened by an incision almost parallel to Fig. 8. — Heart Showing the Interior of the Right Ventricle .and Pulmonary Artery. — (After Virchow.) If the incision M to /, figure 6, be made as advised by the writer, the papillary muscle (.4) ^vilI be carried over with the ventricular wall (B), thereby better exposing the auriculoventricular orifice. the opening made in the right ventricle, but on the opposite side of the septum, and the incision is directed toward the aorta. The pres- ence or absence of blood or clots in the left ventricle must be carefully noted. Examine the great vessels as to abnormality, aneurysm, or other disease discernible externally; gross lesions involving the large vessel trunks, congenital defects, and the presence of thrombi or em- boli had best be determined before the heart is removed; and if pres- ent, it may be expedient to complete the dissection before removing the organ. The heart, whether normal or not, should never be severed from abnormal or diseased vessels when the morbid condition is likelv to have materially influenced the organ; this is especially true of mal- formations and aneurvsms. When the relation of abnormalitv of the I'OSTMOKTKM i: \ A M I NATloXS. I 5 intrathoracic vascular system to the air-passaj,'cs or lun^^s is importaiU. Letulle's method, mentioned below, should he followed. In the new- born it may be advisable at this time to trace the pulmonary artery and aorta, demonstrating the relation of one to the other, and the condition of the ductus arteriosus. Remove the heart, dividing the great vessels from below upward, severing the aorta last. Test the valves as to competency, being sure to wash out all clots before mak- ing the test. Enlarge the incisions already made so as to be able to examine the endocardium in detail. Carry the incision in the right auricle out through the two cavc-c; prolong the incision in the rii'ht Fig. 9. — Heart with the Left Ventricle Laid Open, Showing the Aortic Ccsps and the Vcntricvlab .Aspect of the Mitral Valve.— (^//ujT;h examination siiould be made l)y finger and speculum, using no tutting or pn^he-pfjintcd instrument of any kind until wounds have been excluded — as far as it is possible — before the examination is completed. Evisceration of the pelvis is best accomplished by an incision anteriorly, under the jiubic arch, hugging the true pelvis posteriorly, and removing the rectum with the other contents of the pelvis. The testicle may be removed without any external incision in the scrotum by simply dissecting the skin anteriorly from the pubes and pulling the testicle by the spermatic cord gently up into the wound, from which it may be removed, if necessary dissecting the cord around to the seminal vesicles. The ])enis may be simply retracted through the floor of the pelvis, and rcmf)ved with the l^rostate and bladder. The removal of these organs without the full consent of the de- ceased's family should never be made, as the e.xcision of the genital organs is always looked upon as having been done merely to gratify morbid curiosity, and exactly why it is always discovered seems very hard to determine; the fact re- mains that the uninitiated have been severely censured for the removal of the external genitalia, even in cases where it was perfectly justified by the findings and where it was necessary to exclude other possibilities. The rectum should be dissected from the posterior wall of the bladder in order to expose the prostate and seminal vesicles. In the fe- male, as this is not necessary, the rectum is opened on its posterior aspect, the vagina laterally, and the urethra and bladder anteriorly, thus permitting all the parts to be restored to their normal relation with each other. The opening on the lateral aspect of the vagina is carried anteriorly at the upper end and continued through the anterior wall of the cervix and body of the uterus. If urine be present in the bladder, its character and quantity shoidd be noted, and it should be preserved for future examination. The left semilunar ganglion is examined, and any firmness or in- flammatory signs noted. The ganglion should be preserved for micro- scopic examination. The corresjjonding organ of the right side is next in order of examination. The Sto}uacli ami DnoJcituiii. — In cases where poisoning is suspected, ligatures are applied at the cardiac extremity of the stomach and the upper end of the duodenum, and the organ removed: in order that the contents may be carefully examined, the stomach, without open- 13. — I.NcisioN FOR Separating the Oral a.vd Pharyn- oEAi, Structures from the Ft.oor of the .Mouth. — (Lfliillr.) 1 8 TECHNIC. ing, should be placed in a clean jar and sent to the chemist. In case it is decided to open the duodenum and stomach iti situ, as is best when the question of poisoning does not enter into the case, make an incision along the anterior surface of the duodenum and greater curvature of the stomach. Examine contents, condition, and appear- ance of mucous membrane. Foreign bodies are frequently met with in the stomach. Determine if the bile-duct is patulous by pressing upon the gall-bladder and watching for the escape of bile. In case this simple procedure does not reveal the presence of the ampulla and Fig. 14. — Long, Thin, Brain Knife, of Value for Incising Organs. Originally designed for brain dissection, but at present used for incising kidney, liver, spleen, tumors, etc. As shown in the illustration, the instrument should not have a cutting-edge measuring less than sixteen centi- meters. The graduation along the back of the knife affords a convenient measure. On the other side the graduation is in inches. demonstrate that the cystic and common ducts are patulous they should be carefully exposed. This can not be done after the removal of the pancreas, duodenum, or liver; as it is important in many, if not all, cases to assure one's self of thfe condition of the hepatic, cystic, and common ducts, and as cutting through either of them may render later demonstration unsatisfactory or even quite impossible, they should, therefore, be dissected out in situ. Open the ductus cominunis choled- ochus, examine mucous membrane, and continue the incision upward into the gall-bladder and larger hepatic ducts. Fig. 15. — Enterotoile. Useful for opening stomach, duodenum, intestines, etc. Not uncommonly the blunt-pointed lower blade is so made that it forms a tooth, like the barb on a fish-hook, and when introduced, can not be withdrawn. Such hook-pointed enterotomes are to be avoided. The portal vein, hepatic vein, and vena cava may be opened be- fore the removal of the liver; or, as the first two must be severed dur- ing the removal of the organ, they may be examined at that time. The condition of their contents and appearances of their walls must be noted. The liver may now be detached from the diaphragm, or, if it is adherent to that structure, the two may be removed together; when the lung, liver, and diaphragm are fused by adhesions at their points of contact, and when there may be any suspicion of a suppurative lesion burrowing in either direction, it is best to let the lung remain POSTMOUTHM ICXAM I \ATl0.\ S. in sitit until the i)roper time tor examining the liver, when uir iiim( structures can be removed together; neither the lung nor the liver should be sacrificed, but only that part of the diaphragm immediately involved need be removed with the attached viscera. The shape and color of the liver and any deformities of the lobes should be noticed, the anterior margin examined, and its condition recorded. The inci- sion made to disclose the interior of the liver should lie a long, sweep- ing cut, on the superior aspect of the organ, extending through the longest axis, including both right and left lobes and sufficiently deep to permit the folding of the two parts without tearing the narrow banrl of tissue holding them together on the inferior surface of the organ. On section, the firmness or resistance should be noted; also the color, whether uniform or mottled, and whether or not bile staining be pres- ent. Weigh the organ. Pancreas. — At the time the bile-passages are opened down to and through the ampulla, it is well to seek the duct of Wirsung. and, if possible, the extension into the pancreas: accessory ducts should be sought. As the head of the pancreas is dissected from the duodenum a careful lookout should be maintained for any additional, as well as normal, ducts. Separation of the pancreas from the duodenum, which it occasionally envelops, is often extremely tedious. Aberrant pan- creatic tissue should be sought in the stomach, duodenum, and jejunum. The tail and most of the l)ody of the pancreas may be detached and 1 K.. 10. — l'KUllt>. These should be at least fifteen or twenty centimeters long. One should be very slender. transversely incised partly through, at short intervals (i to 2 cm.), beginning at the splenic end. Careful inspection of the surface ex- posed at each incision commonly discloses the larger duct about the junction of the body and head of the organ. As soon as recognized It may be explored by a fine probe and finally opened. The csophagns should next be examined. Jntcstincs. — A better view of the other organs and greater working room are afforded by removing the intestines immediately after the spleen. The rectum is ligated just below the sigmoid and the latter separated by incising the mesosigmoid close to the bowel. The pres- ence or absence of renal mobility should be detennined, after which the colon, descending, transverse, and ascending, is detached in the order named. The caput coli is raised from its bed, the appendix de- tached from any adhesions, and removal of the small intestine con- tinued by sectioning the mesentery as close as possible to the gut. As the different parts of the ileum come in view any abnormalit\ in color, evidence of inflammation, dilatation, or narrowing should lead to a closer examination of the mesentery, which ordinarily is inspect*^'! ■» this time. While dividing the mesentery watch for enlarged g! cysts (chylous), tumors, thrombosed vessels, fat necrosis, etc. Vv n. u the blood or chylous vessels are abnormal, it may be well to remove these with, and leave them attached to, the intestine. Should thrombi. TECHNIC. or other lesions involving the vessels, be disclosed, the veins and ar- teries should be dissected to the main trunks, and if possible the cause, if local, determined before going further. Any lesion located in the mesentery' and influencing the intestine should be traced with that structure to which it had best be left attached. The gut should be carefully opened, and the contents examined as the incision in its wall is gradually extended. After the incision made by the enterotome has been concluded the mucous surface should be gently washed by a slowly flowing stream of water, and examined for inflammation, ulcers, cicatrices, perforations, constrictions, etc. It is best to open the intestine before washing it out, in order more accurately to determine the contents, ex- amine for animal parasites, locate foreign bodies, etc., but cleanliness and con- venience often lead 'to an unwise reversal of the proper order. In cases of suspected poisoning the unopened intes- tine should be sent, in a clean jar, to the chemist. The thoracic duct should now be traced, and the retroperitoneal glands and rcceptacidum chyli examined. The aorta and its branches may now be examined in detail. The Head.^ — Insert the scalpel, with its back toward the skull, just behind one ear, and carry an incision across the vertex, cutting from within outward. If the knife is not too sharp, the hair may be parted and Fu;. 17. — Dissecting Forceps. One of these should be toothed. These will be needed in the finer dissections, as in tracing the hepatic duct, portal vein, and re- ceptaculum chyli. Fia. 18. — Mallet or Hammer. thrown backward and forward as the hand and knife are withdrawn. The incision should be far enough back to be invisible from the front when closed. The scalp is reflected forward and backward from this incision as low as the superciliary ridge in front and the occipital pro- tuberance behind. In many cases great care must be used to avoid a tear at or ' See article by Biihlig on general and special methods for examining the brain and spinal cord; "Cleveland Medical Jonr.. " Jan., 1904, p. 28. POST M « ) K T !•: M !•: X A M 1 X A '1 I O N S . around the ear, as tension is produced by ])ulling the anterior and posterior scalp-flaps down; to avoid this unsightly tear, which may run down in front of the ear. insert the knife under the skin, in the incision already made, just behind the ear, and dissect the skin free from the deeper structures behind and in front of the ear. The scaljj-flaps, as already de- scribed, do not include the temporal fascia or muscle, l)oth of which are now cut through and reflected in the line of the contemplated saw-cut. All soft tissues should be incised and pushed out of the way of the saw, otherwise they pack the teeth of the instrument and greatly impede saw- ing. When the skull-cap is replaced, the fascia and the muscles may be sewed together, thereby securing the bone in place — a matter of great importance in private postmortems when the body is to be exposed at a funeral or to friends. Inspect the skull for evidence of injury or disease. In opening the skull there are three methods of procedure— one should never be used when it can be avoided, one may be used in a few cases, and one is applica- ble in the vast majority of instances: (i) The "un- dertaker's cut" is made by sawing across the forehead just back of the hair line, from one temporal fossa to the other, and carrying a second saw-cut around the posterior base, parallel with the base line, joining the anterior cut in each temple. This method does not per- mit of satisfactory removal of the brain. (2) The second method should always be used in medico- legal cases, and whenever the question of fracture mav arise. It does not dernand the use of a chisel, and affords abundant opportunity for ex- amining the interior of the skull. A circumferential line is drawn around the skull, on a level with the superciliary ridge in front and the occipital protuberance posteriorly, and the skull sawed through at this line. (3) The third method, and 'the one most commonly employed, consists of a V-shaped incision; as viewed laterally, the anterior arm of the V is parallel with the l)ase of the skull, on a level with the su{)erciliary ridge, and extends backward i cm. behind the external auditory meatus. The other arm of the saw-cut passes obliquely across the vertex just back of the incision already made in the scalp. It may be necessary to break out the angles of the saw-cut with a chisel; care must be used not to mutilate the ear in making the saw-cut. The adjustment and retention of the calvaria in place mav be further aided by making the posterior saw-cut also V-shaped. The angular junction of the two lines which form the V is directed upward, something like the occipitoparietal It is ig - Heavy Link I.ndk atinc Covrsf. Tak: ' t in So-called Undertaker's Method. possible that the base line as drawn in this illustration is too low, however, this is immaterial, as the method is under all circum- stances to be avoided. TECHXIC. suture. To repeat: This makes two V-shaped saw-cuts as follows: Viewed laterally, the anterior arm of the first V is parallel with the base line, and extends from the superciliary ridge to just behind and above the external auditoiy meatus, the posterior arm of this V being sub- divided into the two arms of a second V, which, as viewed from behind, is upside down. The advantage of this incision lies in the easily adjusted calvaria, the wedge-shaped cap being readily replaced and secured in position, so that no external evidence of the postmortem will be visible when the scalp is returned to place and sutured. Inspect the interior of the calvaria for evidence of injury or disease, noting its thickness and the condition of the diploe and of the external and internal tables. The dura may be removed, or, rather, reflected back, by incising it along the lower saw-cut and detaching the falx cerebri from the crista galli. When, as in the very young, the dura must be removed with the calvaria, it is necessary to incise that membrane along the line of the saw-cut, and to sever the falx ante- riorly and posteriorly be- fore making any attempt to raise the skull-cap. Inspect the surface of the brain for superficial injuries or disease, but make no incision into it. It may here be necessary to note the relation of l)rain landmarks to the skull, fixed points of the latter being selected for the comparison. The brain is next to be removed, beginning in front by carefully raising it from the base, being sure to raise the olfactory bulbs with the hemi- spheres ; still cautiously elevating the hemispheres, sever the nerves as they pass out of the skull, those in front first, and then in order as they appear. AVhen the tentorium is reached, detach it from the temporal bone and follow the base, severing the nerves as they find exit from the posterior fossa; lastly, pass a long, slender-bladed knife along the basilar pro- cess of the occipital bone, and down into the spinal canal, cutting the cord as low as possible. In order to section the cord as nearly trans- versely as possible and to avoid the oblique incision made in the manner just directed, some operators prefer the use of a myelotome. After section of the cord the entire brain can be easily removed. Complete the examination of the interior of the skull, noting the condition of the bone, blood-vessels, sinuses, etc., dissecting the dura from the base to facilitate the examination of the bone. Before detaching the dura the contained sinuses should be opened and examined for evidences of thrombi, septic processes, etc. The posterior part of the orbit and the FrG. 20. — Circumferential Saw-cut, to be Preekrred i.\ -Axl Medicolegal Cases. The exact location of the line will vary slightly, depending upon the conformation of the skull. It is usually about as indicated above. P ( I S T M () K T i: M EXAMINATIONS. eveball may l>c oxaniintHl by ihiseling the root"; in the same way examine the frontal, sphenoid, mastoid, and ethmoid sinuses and the internal ear.' The bniiii should be, in most instances, hardened before dissection ; if this can not be done, immediate examination may be made as follows: Make a careful examination of the meninges, and note the color, con- sistency, etc., of the external surfaces, including the base; the con- sistency is best determined by gently palpating the entire cortex. Ex- amine the blood-vessels at the base, tracing them into the brain-tissue. An incision is made on each side, just over the corpus callosum, into the lateral ventricles, and continued backward and forward, that they may be carefully inspected; the amount and character of the fluid i)resent are noted. ' The lateral ventricles are joined by an incision through the fornix, reflecting the corpus callosum backward, exposing the tissues beneath. Search for hemorrhages, areas of softening, tinnor'; m- flammation, abscesses, etc. Lateral incisions are now made in the cortex from the ventricle outward, so as to note the condition- of the cerebral substance: the incisions should be parallel, not over one cen- timeter apart, and the membranes should not be cut through, as they will retain the cut parts in position. The brain is then turned over, and the tissue of the base exam- ined by transverse incis- ions through the medulla, cerebellum, etc.. examin- ing for such changes as previously noted. Weigh the brain. While occasionally much information can be obtained by the gross ex- amination of a freshly removed brain, improvements in histologu technic have made the microscopic examination of greater importance. In order to obtain valuable information from this method, it is neces- sarv to secure sections which permit reconstruction of the organ, s<. that the connection between different parts may be traced. This ini- \)\\es the use of some serial method similar to that employed in em- bryologic work. The size of the human brain precludes satisfactorv serial sections of the entire mass, and as the serial sections are for the puqiose of demonstrating histologic lesions in paths or bundles, each case will become to a certain extent a law unto itself. In the interest of complete neurologic investigation the pathologist must forego the satisfaction of immediate results from dissection of the froh ^^am. ' Schalle (Virchows Archiv," Bd. Ixxi. p. 206) gives details -i r txamininc' the- ort;ans at the base of the skull, using a chain >:nv KiG. ;i. -Wedge-shapkd Calvaria Removed by the Link u SAW-ruT Recommended. (See Text.) Il the posterior cut is so mafle. from the right and left sides, that ihr point just above the figure 7 will l>c the apc.x of a triangle, two sides of which are formed by posterolateral saw-cuts, there will be no difficulty in retaining the wedge-shaped calvaria in plan- 24 TECHNIC. It is desirable to harden it in formaldehyde-water (formalin lo parts, water 90 parts) for several days before making any incisions except those through the margins of the corpus callosum into each lateral ventricle, which are preliminary to all methods of dealing with the brain, and are simply to promote hardening of its interior. If, how- ever, incisions are to be made at once, the pathologist should consider, in relation to any gross lesion present, the direction of tracts which liHiiiilliihiilinlili Fig. 22. — Chisels. If on]y one is to be purchased, the lowest one will be of most use. mav be degenerated. Such tracts should be cut at right angles to their course in order that the sections may be used for micro- scopic study. In this point of view the conventional methods of Vir- chow and of Pitres are objectionable. The safest single incision is Dejerine's horizontal cut passing through the cerebrum at a level slightly beneath the upper surface of the callosum. This transects the basal ganglia and the internal capsule at their widest parts, and will usually reveal anv gross lesion. If this is not conclusive, another section may Fig. 23. — Myelotome. Used for separating the brain from the spinal cord. The advantage claimed for this instriiment is the facility with which the cord may be cut transversely, thereby avoiding the objectionable oblique incision which is usually secured when the ordinary knife is used for the same purpose. be made i cm. lower than the first and parallel to it. A section lengthwise of the optic tracts will show their connection with the pri- mary optic centers, and at the same time the nuclei and fibers of the third nerves. To reserve the remainder of the brain-stem for microscopic study of its nuclei and nerve-roots, the most advantageous section is a trans- verse one in the upper half of the pons; that is, above the fifth nerves, which are about half-wav down the pons. Above all to be avoided I'O ST M t ) RT 1-; M !■: X A M I X A III) X • arc longituelinal bisections ol the bram-stcin. For the study ot nerve- cell bodies and of neuroglia small portions of the fresh tissue, removed from the paiticular centers of the cortex, and from the cervical and lumbar cord, are put at once into the special fixatives. For Marchi and Weigert pre|)arations and for nuclear and general staining, the bulk of the brain and cord may be placed in Muller's fluid, or in Orth's mixture for twentv-four to forty-eight hours, followed by Muller's fluid.' J he Pitrcs-Xo'tlnia^il Mctlwd. — The lateral ventricles are opened as described; the pons and cerebellum are severed by section of the pe- duncles; the cerebrum is divided by a vertical section (longitudinal) through the median line — the third ventricle; each half of the cere- brum is then incised from above downward, transversely to its long axis and as nearly as may be parallel with the fissure of Rolando: (i) Five centimeters m front of fissure of Rolando; (2) through posterior margin of the frontal convolutions; (3) through ascending frontal con- volution; (4) through ascending parietal convolution; (5) three centi- meters posterior to hssure of Rolando; (6) one centimeter in front of parieto-occipital sulcus. The fixation of each of these sections completed, serial sections are made from each area. While much more tedious and requiring greater care, this method permits of reconstruction and the adapt- ation of parts so as to follow fillets, or paths, with a pre- cision not possible by the cruder methods. For demonstrating the condition of the blood-vessels at the sacrifice of everything else, the brain may be gently washed away and the blood- vessels floated out in a l)asin of water. The Spinal Cord. — The body is turned upon the abdomen, and blocks are so arranged as to arch the vertebral column. As this pro- cedure mav cause leakage of fluids in a body already opened ante- riorlv, it may be best, in private postmortems, to examine the cord first; after the body is turned on the back, little if any fluid should escape through a properly closed posterior incision. An incision is then made through the skin, over the spinous processes, extending from the occiput to the sacrum, and the muscles, fascia?, etc., detached from the vertebra- so as to expose the lamina* on both sides. These are then sawed through, the saw being held i)arallel with the spinous processes and near the junction of the lamina- and pedicles. The sec- tion extends from the second vertebra to the sacrum. The excised strip is now removed, the chisel or bone-cutting forceps being used as aids if necessary.- Inspect the meninges and remove these with the cord, carefully detaching, with a sharp knife, th,- Ti.TVP-rnots; as t!u-.- ' For formulas sec chapter on Histologic Technic ^ Chavignv ('La Prcssc Mddicale." July 20. 1904, p- 400/ atsi.nl. genious lever device l"<^r removing the spinous processes and lammav I h. used it. but LetuUe writes me that it is a useful appliance. Fic. 24. — Sc.\LPEL WITH Blade Shaped Sf)MK\vHAT like a BlSTOfRV. Useful in removing ihc brain and spinal cord. The aneurysm needle and tenaculum shown arc useful at limes not essential. but are 26 TECHXIC. pass out of the canal. The lower end of the cord, with its membranes, is first detached, and the removal continued from below upward. Dur- ing the removal of the cord, whatever traction may be necessar}^ should be made on the niciiiiiges only, and traction on, or crushing of, the cord should be carefuUv avoided. After removal of the cord examine bodies of vertebrae; dissect out and preserve a number of the intervertebral ganglia. Open the dura in the median line posteriorly and examine the cord by making transverse incisions one to two centimeters apart. The examination of the joints and bones of the skeleton may have preceded the visceral examination, but ordinarily it is deferred until that has been completed. Sometimes it is desirable to obtain bone- marrow without fracturing or otherwise severing the continuity of the bone. This is best accomplished by two saw-cuts parallel, four or five centimeters apart, and extending a little over half-way through the bone; by means of a chisel this block of bone is split out, bringing with it the marrow. A block of wood may be slipped into the space occupied by the piece of bone removed, and, where this fits tightly, bringing the tissues together over it will usually prevent the occurrence of a fracture during the ordinary handling of the body. Fig. 25. — Double Saw (Rachiotome) for S.^.wing through the Lamin.e of Both Sides at Once. It saves time and labor, but equally good work can be done \rithout it. The removal of the salivary glands is not often demanded. The sublingual and submaxillary glands may ordinarily be removed by the method already described when considering the larynx and pharynx. A portion of the parotid gland can sometimes be removed by dissect- ing the skin down from the temporal region anteriorly, and below the incision already advised for exposing the skull. By LcHille's method^ the neck and the thoracic and abdominal cavities are eviscerated en masse and the subsequent examination of the organs begun and to a large degree completed while they are still attached together. To accomphsh this, the preliminary incisions, in- cluding opening the abdominal cavity, are those for which directions have alreadybeen given (pp. 7 tog). A long knife is passed upward through the floor of the mouth, separating the tissues from the inner surface of the inferior maxilla; the uvula and palatine arches are freed from 1 I have taken some minor liberties with Letulle's plan, which to one having a thorough knowledge of anatomy and some experience in postmortem work. I think can be stronglv recommended. .loKTKM KXAMlNATItiN: their osseous altaclimcnts. The posterif)r wall ol" the j»har>ii.N ■.> -U- tached from the subjacent bone and ])ullcd downward. The large arterial trunks in the nock and the subclavian vessels are divided; the entire mass is now ]nilled downward, the section bcin^ maf formaldehyde gas. The original formalin was cxpen.sivc, bu' solutions, under other names — as formalosc. formol — can be > price making preservation by this method cheaper than with ni. ti 32 TECHXIC. to those obtained by that devised by Kaiseriing, of which many modi- fications have been suggested.^ Two solutions are necessary; Si>lu:ion A . Solution B. Formalin 250 c.c. Acetate of potassium. 200 gm. Nitrate of potassium, . 10 gm. Glycerin 400 c.c. Acetate of potassium. 30 !^m. Water 2000 c.c. Water i liter. Thymol to saturation. The specimen to be preserved is quickly and lightly washed in water to remove adhering blood only; it is then placed for from one to twenty-four hours in solution A, at the end of which time it is changed to fresh solution A, where it is allowed to remain for from two to thirty- six hours. Wash in running water for from fifteen minutes to one hour and transfer to eighty per cent, alcohol; as soon as the color begins to reappear the specimen is transferred to ninety-five per cent, alcohol, in which it should be allowed to remain until the color is fully restored. This process of development in the alcohol must be watched closely, for if allowed to go too far the color will be irretrievably lost; as soon as the color is restored transfer the specimen to solution B, which, at the end of twenty-four to forty-eight hours, had best be changed, as any residual alcohol tends to bleach the colors. In order to prevent the growth of molds solution B must be kept saturated with thymol, a small lump of which should be left constantly in all vessels containing the fluid. The same result can be accomplished by adding formalin, 0.75 to i per cent. Specimens prepared by the Kaiseriing method may be preserved without fluid in air-tight jars containing a luinp of th3miol. Little - John recommends this method for the preservation of stomachs from cases of corrosive sublimate, carbolic acid, and creosote poisoning, which may be kept indefinitely in air-tight jars, bacterial growth be- ing prevented by the poison contained in the specimen. Small cysts, such as those of the echinococcus, are best preserved in a ten per cent, aqueous solution of chloral. ^ See papers by Coplin and also Herring ("Jour. Amer. Med. Assoc," August 13, 1904); Watters ("N. Y. Med. Jour.," August 23, 1902); paper by M. E. Ab- bott ("Amer. Med./' April 4, 1903) on the "Classification of Museum Speciinens " ; also the writer's papcjs in the "Proceed, of the Path. Soc. of Philadelphia," 1903- 1904 and 1904-1905. For the "Dangers of Formol " see Spitzka ("Science," July 17, 1903, p. 87). CHAPTER 11. HISTOLOGIC METHODS.' Fixation. — Sections of the fresh tissue may be cut either free-hand or by means of Valentine's knife, which consists of two parallel blades of the utmost sharpness, separated from each other by a small aper- ture just as wide as the section is to be thick. Both methods are unsatisfactory, and are rarely used. Fresh tissue may be cut by freez- ing, as will be directed later, but for a satisfactory study of cell chem- istry and morphology, and tissue architecture, it is especially important to subject the material to the action of some agent which will destroy all vitality, arrest metabolic and lytic processes, and prevent, as nearly as possible, all those postmortem changes which lead to chemic and structural alteration. This process is called fixation and the agents used fixatives. The following are especially commended: (a) Chromo-aceto-osmic acid mixture (Flemming's solution). For this solution keep on hand the following stock solutions, and make up for use as wanted, in the proportion given: (^)uijnli,'y neeiltd lo makf Slock solutions to be kept on hand. up FUniming's solution. I per cent, aqueous solution of chromic acid 25 volumes. I •• ■' ■• ■■ osmic ■■ 10 I •• ■■ acetic .10 Water, . . .55 All the water used in making the stock solutions or the final mix- ture must be distilled, and all containers should be chemically clean and dust-free. Fixation of small pieces will be complete in from one-half to two hours, although a longer time may do no injury. A period beyond a few hours, however, is likely to make the tissues brittle. After fixa- tion, wash thoroughly in water. This is best accomplished by wash- ing in flowing water for at least six hours. Proceed to embed at once or preserve in seventy per cent, alcohol until needed. (6) Platino-aceto-osmic mixture (Hermann). Like the foregoing, it is best freshly prepared: Quantity nftdrd lo makr Slock solutions lo be U kept on hand. up abm^ solution. 1 per cent, aqueous solution of platinic chlorid 15 volumes. 2 ■' " " "1 >sniic aciil 2 Glacial acetic acid .1 velum. ' In the present edition of thi> hhok in. ii na\< nvi n him rtcd, whi importance seemed to demand it. such technical direction.s as may 1 for the demtmst ration of special reactions or methods. When seau! rections bearing on some point, the student is advised t<> consult the attempt can he made in such a work as this to go into the sul>i> . ♦ technic with elaborate detail. A few methods can be taught, it ; oughly; but for further detail as to special methods the student li ize himself with that best of all books for the worker with the r Microtomists Vade-mecum." by Arthur Belles Lee. See also ret' 4 33 34 TECHNIC. This solution is used as already directed for Flemming's solution, and should be followed by the same careful washing. Tissue so pre- pared may be treated as already directed for tissue prepared in Flem- ming's solution. (c) The most useful fixing agent for general use is corrosive sub- limate. In solution it keeps w^ell and fixes thoroughly, although for pure cell study the foregoing solutions are probably better. Heiden- hain's solution is prepared by dissolving 125 gm. of corrosive subli- mate in a liter of 0.5 per cent, solution of sodium chlorid in water. The solution of the corrosive sublimate being effected in the boiling salt solution, on cooling its crystals are thrown down, but are again taken up as the solution is used over. Small pieces of tissue fix in this solution in from one-half to two hours. The used solution is fil- tered back into the stock solution, and the tissue washed in water or, what is better, seventy per cent, alcohol. A little experience soon enables one to infer when the stock solution has become exhausted. The fixing solutions of Zenker, Petrunkevitch. and Bensley are also excellent for routine work. Petrunkevitch' s Solution. Bcnsley's Solution. Alcohol, absolute 200 c.c Potassium bichromate, i % Water 300 c.c. aqueous solution, 50 c.c. Glacial acetic acid,. . . . 90 c.c. Corrosive sublimate, saturated Nitric acid, pure cone. 10 c.c. alcoholic solution, 50 c.c. Corrosive sublimate, . . 55 gm. Glacial acetic acid, 5 c.c. The solutions must be kept separately and mixed when needed. The tissues are transferred from this solution to seventy per cent, alcohol containing a trace of iodin; this should be changed frequently and the specimens kept in seventy per cent, alcohol until needed. Zenker's, Bensley's, and Orth's fluids require from twelve to twenty- four hours for fixation; the tissues should then be washed in running water and finally carried through iodized alcohol. Tissues fixed in mercurial solutions contain crystals which must be removed, as they obscure the microscopic picture, and, I am inclined to beHeve, cor- rosive sublimate left in a specimen renders it more dense, and with hard structures such as fibrous tissue and masses of unstriped muscle (uterus), the intense hardening may prevent satisfactory sectioning. The corrosive sublimate may be removed after sectioning (p. 41) or during the process of dehydration; if the seventy, eighty, and ninety per cent, alcohols are faintly tinged (light canary yellow) by the addi- tion of iodin, the sections will contain no mercurial precipitate; the iodin must be thoroughly removed in subsequent alcohols, otherwise the tissues will be brittle. In fixing by any of the above methods, the tissue should be in small pieces, not larger than 0.5 to i cm. cube. The quantity of the fluid used should be abundant, and exceed several times the volume of the tissue to be fixed. For the preparation of tissue containing nerves, or the central nervous system, nothing has been more generally used than bichro- mate of potassium. It is used in two to five per cent, aqueous solu- tions, or as Muller's or Orth's fluids (p. 31); it also enters into Zen- HISTOLOGIC MKTIIODS. 35 ker's and Erlicki's solution, the former much, and the latter but little used. /.cnkrr's Solution. Eriirkis Solution. Corn^sivc sublimate. 2.5 gm. Potassium Ijichro- Mullcr's tiuiil loo.o cc mate 2 jjm. Just before using add Clipper sulphate. ... 1.08 gm. Glacial acetic acid 5.0 c.c. Water 100. o cc. Orth's and Erlicki's fluids fix and harden much more rapidly than Midler's fluid alone; in either of these solutions a spinal cord would require but two or three weeks, or even less, while with Miiller's fluid a much longer time is necessary. Alcohol is sometimes used as a fixative. To be efficient it must be as nearlv absolute as possible. Weaker solutions give rise to easily recognized and quite characteristic artifacts. When rapid fixation and coincident dehydration are desirable, a saturated alcoholic solution of corrosive sublimate may be used. For the demonstration of bacteria in tissue, fixation by alcohol is permissible; it has, however, no ad- vantages over corrosive sublimate, even for this purpose, and is always associated with a verv grave disadvantage, in that one desiring to study the nuclei mav find that the fixative has not properly preserved them. Alcohol is largely used as a dehydrating agent and for the preserva- tion of tissues during the interval "between fixation and the final steps in the embedding process. It is the ideal agent for neither purpose, but for the present it seems to be the best that we possess. SECTION CUTTING. Infiltration Methods. I. Paraflan. — After fixing and washing as already directed, t'ne tissue to be infiltrated is dehydrated by passing through alcohols of increasing strength — seventy per cent., twenty-four hours; eighty per cent., twenty-four hours; ninety per cent., twenty-four hours; absolute, twenty-four hours. As alcohol does not mix with par- aflin. it must be displaced by some paraffin solvent. For this purpose numerous reagents have been used, such as chloroform, turpentine, xylol, toluol, benzol, cedar oil. and many allied bodies. Many of these alter the tissues; probably all of them do slightly, but the least ob- iectionable is cedar oil. From absolute alcohol the tissue is car- ried into the clearing agent, pre- ferably cedar oil, and, to make the change gradual, the cedar oil is r u ■ diluted with an equal part of absolute alcohol ; after twenty-four hours treatment in this mixture the tissue is transferred to pure cedar oil for jL Fig. 30. 1-lat-iron-shapcd copper t.ihlf. whirh may tio usc<) for paraffin infillr.i'' " " ■--•'- m of IiKkmI l'ilm<. !■ :"'l under t^-- ii[> '■' "'' right '■'' to a " end • '"•« oft.-. part hot. small luriiiin .11-11 1- I'l.iii'i ">ii the paraffin is kcpl barely melted. 36 TECHNIC. twenty-four hours, and then to cedar oil containing sufficient paraffin to thicken it perceptibly ; twenty-four hours later the specimen is placed in melted paraffin, the melting-point of which should be 50° C. in summer and 45° C. in winter. The paraffin must be kept as near the melting- point as possible by means of a paraffin oven and a thermoregulator. After from six to twentv-four hours the tissue is transferred to fresh Fig. 31. block of hard wood or of rubber fiber as usual received in the laboratory. Same block as figure 31, with corners properly trimmed to receive paraffin or celloidin for embedding. Fig. 33. Method of applying paper to block. paraffin at the same temperature, in which it is kept from twelve to twenty-four hours. The gentle heat, continuously applied, displaces the cedar oil and permits the paraffin to infiltrate the interstices of the tissues. One end of a wooden block — about a two-centimeter cube — is warmed over a Bunsen burner and dipped in the melted paraffin. It is then wrapped with a strip of paper four centimeters wide, so that the HISTOLOGIC METHODS. paper projecting from the warmed and toated end ot" the bhxk forms a well deeper than the tissue to be mounted. The l^lock of tissue is then ])laced in ])Osition at the bottom of the well, arranged to eut to the best advantage, and melted parafhn poured in until the well is filled. This is allowed to cool and the ])aper is then removed. The paratfm is now gray. appears granular, and is said to be in the crystalline form; if put in a wami place. — care being taken that it is not warm enough to melt the paraffin, — it soon becomes transparent, or, it is said, the paraHin becomes amorphous, homogeneous, or hyaline. The block is now ready to cut. It is trimmed down nearly to the tissue, each side being cut so as to present a surface square to the knife, the general aspect of the block being that of a truncated pyramid. The ])araffin trimmed ot^f is remelted, and may be used many times. The block is clamped in the holder of the microtome so that the cutting-edge of the knife strikes scjuarely against the block along its whole length; \ \ N A ir--1 r--" 1 ^ .! \ ^L J\ > '■^ c k. Kk.. 34. Fig. 35- PArxT (.\. .\. A. .\> proixrlv wrapped around block (C). with block of tissue (B) to be embedded, readv for pouririK the paratlin in and comi.Uling the cast. .After the ca.st cools (sec text) the paixTXS removed and the parathn is trimmed, as shown in litjurc 35, carefully avoiding the block of tissue, which should be thoroughly covered by the paratlin at all ix)ints. the knife is so arranged that it cuts like a chisel, and not with a drawing motion. To get the best sections, the paraffin must be of the proper temperature, as this determines the density; in summer the block may have to be cooled bv ice; in winter it may require warming. The most imi)ortant factor in paraffin infiltration is thorough dehy- dration and clearing. Absolute or approximately absolute dehydration is necessarv in order to secure penetration of the clearing agent— cedar oil, xvlol, or whatever it may be. If the pieces of tissue are small, the stages of the process may be shortened. Tissue kept too long in strong alcohol or in the clearing agent or paraffin (warm) not infrequently becomes brittle. The occurrence of this condition should lead the worker to shorten the stages sufficiently to overcome the difficulty. When osmic acid methods have been used for the purpose of determining the presence of fat. the clearing agent and paraffin may. under some TECIINIC. conditions, partly remove the fat. In osmic acid preparations, when the fat is to be retained, celloidin infiltration is to be preferred. It will be seen that the foregoing process requires days, and to overcome this objection Reeves has recommended the following: (i) Fix in saturated alcoholic solution of corrosive sublimate for one hour. Sf rifflk Fig. 36. — Naple's Paraffin Bath for Infiltrating Tissues in Paraffin. The apparatus consists essentiaOy of a series of receptacles for holding the melted paraffin, with a surrounding water-bath retained at an even temperature by a thermoregulator. Bv this method fixation and dehydration go on together; (2) absolute alcohol, one hour; (3) xylol, one hour. As xylol has a very low vol- atiUzing point, it quickly evaporates in the paraffin bath, and permits the rapid penetration of the paraffin; it is kept one hour in the first Fig. 37.— Forceps Convenient for Handling Cover-glasses, Blocks of Tissues and Sections. paraffin and one hour in the second, when it is cast. In order to pre- vent crystallization of the paraffin the cast is plunged into ice- water as soon as its surface has cooled sufficiently to form a thin film ; the cooling may be facilitated by holding the block out of the window in winter or bv gently blowing upon it in summer. The cast is now MISTt)LOC,lC MKTIIonS. S9 trimmed and rut. Of course, the pieces of tissue to be prepared in this way must he very small, — not over 0.5 cm. cube, — and the re- sults can not be considered as comparable to the slower method already described. Fig. 38 — Laboratory Microtome. Can be used, as shown in the cut, for celloidin sections; an attachment for freezing may lie &ul>stitulee — and place the section on the water; gently warm the slide, being careful not to melt the paraffin; as the section becomes warm it will straighten out, all folds and wrinkles disappearing. Now carefully pour off the excess of water, and the section falls upon the layer of albumin. Fig. 41. — Ra-vvier's Microtome. Blocks of tissue infiltrated with ceUoidin or paraffin may be cut in sections free-hand with an ordinary razor; better results may be oVjtained by even so simple a microtome as the above ( Ran\-ier's microtome) or very much better results by the Ryder, Minot. or Bausch and I.omb instruments. — (Illustration jrom Gould's Dictionary.) to which it adheres. ^Mayer's albumin is composed of egg-albumen (white of egg) and glycerin, of each 100 c.c, to which one gram of salicylate of sodium has been added to aid the glycerin in preserving llISToI.oC.U" MI'TIIODS. 4J the albumin; after tliorou^hly mixing, the mass is filtered throuj^h paper — a process requiring' weeks. The alhumm fixes the section to the slide, so that it may be taken through the subsequent processes without danger of becoming detached. After the section has been drained of the water upon which it was floated to facilitate flatten- ing, it is placed in a drying oven to get rid of any remaining water. In ordinary work where no great haste is demanded the slide may be placed in some warm place, protected from the dust, until perfectly dry. After drying, which may require from f(nir to twenty-four hours, the slide is gently warmed until the ])arafhn just melts, and no more; it is then thrust into ordinary kerosene, or. what is slightly better but much Fig. 43. — Mjnot Microtomf.. Iwi. -i/c- ui ihc inMruni, III in lu.i.ic: the illustration i- •■' •'>■■ -'-'l'' al)ove the knife is inienflcfi to receive the block of ; The writer has found this extremely difficult and ic: catcd orienting attachments shown in the cut, and >; of cementing the tissue to the microtome. ,1 pl.Ur j.. more expensive, xvldl; either of these quickly removes the parattin usuallv requiring about fifteen minutes: wipe oflf the excess of xylol, rinse the mount" in alcohol, and place the slide in that liquid unti the xvlol is removed. From the alcohol the section is stained as will be directed later. If the tissue was fixed in a solution containing mcr- cur\' this must be removed bv treating the section with tincture o iodin. in which it is immersed for fifteen minutes; it is then waslicl with a few drops of alcohol and placed in a jar of alcohol, from winch it i'^ removed for staining when desired. If tlv> l.V.. V ot tissue was 42 TECHNIC. carried through iodized alcohol, the section need not be treated with the tincture. 2. Celloidin Infiltration. — Celloidin is a proprietary product hrst used in photography, and is nothing more than a nonexplosive gun-cotton. As used, it is dissolved in equal parts of alcohol and ether, thus making a collodion that, so far as the author can observe, has no advantage over a good collodion made from gun-cotton. The alcohol used for this purpose should be absolute; the solution will be facilitated by placing the celloidin in a tightly stoppered bottle — a citrate of magnesia bottle is to be recommended — and pouring on the absolute alcohol, which should be allowed to remain in contact with the celloidin for twenty-four hours, when an equal volume of ether should be added. By this method Fig. 43. — Drying Oven. ' Three tubes for admitting air to interior. At D are three similar 'e.xit tubes. B. Shelves upon which slides are placed at the student's desk, from which, after labeling each slide and placing under the slides a piece of paper with his name and desk number, he places the tray in the oven. C. Thermometer. £. Thermoregulator. F. Water-gage. G. Cock for emptying the water space. The temperature of the oven should never reach the melting-point of the paraffin, and had best be between 37° C. and 40° C. solution will be complete and no time will be lost. As ordinarily used, two solutions are needed — one a thick, syrupy solution, and a second thin solution made by diluting the thick solution with an equal quantity of absolute alcohol and ether. The tissue to be infiltrated is fixed and dehy- drated as already described for paraffin; it is then placed for twenty- four hours in a rnixture of equal parts of alcohol and ether. From this the tissue is transferred to the thin solution of celloidin. The l^est results are obtained by leaving the mass for infiltration several days hi this solution, when it is placed for an equal length of time in the thick solution. A block is then soaked in alcohol and ether for one or two hours or longer, and one end is coated with celloidin and wrapped in paper, as already directed for paraffin. Into the well the infiltrated HISTOLOGIC METHODS. 43 piece of tissue is placed, arranged as desired for tuiiiii^, .iiim tiic ihick celloidin solution is poured over it; the mass, whith is now said to be cast, is placed under a lightly fitting bell-jar or cover until the celloidin begins to set, when it is thrown into eighty per cent, alcohol fcjr harden- ing. At the end of twenty-four hcnirs it will be found sufticiently hard for cutting, but it may be kept indetinitely in the alcohol and cut when desired. Unlike parathn, celloidin must be cut with the microtome knife at an angle to the block, — that is, with a drawing motion, — and, while the paraffin was cut with a perfectly dry knife, the celloidin must be cut with a knife kept flooded with eighty per cent, alcohol. Each section is removed from the knife as cut and is transferred to eighty per cent, alcohol, in which it may be preserved until wanted for use. The great advantage claimed for celloidin is that, unlike paraffin, it need not be dissolved out before the section is stained. Stains such as carmin and hematoxylin may be used, the celloidin holding the sections together during the manipulations incident to staining. Gilson's Method. — A satisfactory method of celloidin inhltration is that devised by Gilson, in which, after dehydration and treating with the alcohol and ether mixture, the tissue is placed in a test-tube con- liKfSH SCITABI I taining several cubic centimeters of thin celloidin .solution; after a few davs in the thin celloidin, the test-tube is immersed in a water- or par- affin bath at about 42° C, at which temperature the solvents (alcohol and ether) rapidly evaporate, thereby hastening penetration and increas- ing the density of the infiltrating mass. When the solution has evapo- rated to about one-third its original bulk, it is turned out and cast as in the slow process. The hardening of the block is greatly facilitated and the results are improved by hardening in chloroform. The chloroform hardening process is applicable to blocks that have been infiltrated either by the slow or by the rapid method. As soon as possil)le after the cast is made the mass is placed in a desiccator or sieve dish, or in a bottle containing a teaspoonful of chloro- form and having a tightly fitting stopper. A support is arranged al>ove the chloroform, on which the block to be hardened is placed, and the vessel is then tightly closed. From two to twelve hours will be sufficient for the hardening, after which the block is placed in a mixture of cedar oil two parts and chloroform one part; more cedar oil is added from time to time until nearly pure cedar oil is attained. The sections are cut drv, as in the paraffin method. The block ni '■eser\'ed in- 44 TECHXIC. -GROUND SURFflCd. CROSS SECT/ON PtQ SHOWING SUD£5 W POSITION. definitelv in the cedar oil.' After cutting, the sections are washed in alcohol in order to remove the cedar oil, and may then be stained. Sections obtained by the celloidin embedding and infiltration process may be secured to the' slide by ether vapor or by a very thin layer of celloidin. The best method is to float the section on to the slide, blotting it carefullv with bibulous paper, and, from a bottle containing a small quantity of ether, to pour the vapor upon the section. This will" suf- ficientlv soften the celloidin to make it adhere to the slide during the subsequent manipulation. It is to be remembered that celloidin sections must be kept moist throughout the entire course of their preparation. Drving them is, as a rule, injurious, if not destructive. '3. Congelation Method. — Fresh tissue may be frozen and sectioned, but the best method is that of Hamilton: (i) Harden; (2) wash out the hardening fluid ; (3) place in sugar solution for from two to twenty-four hours ; this solution is composed of two ounces of sugar dissolved in one fluidounce of water ; after removing from the syrup, wash lightly in water and (4) place in mucilage for two hours. The tissue may now be put on the drum of the freezing microtome , frozen, and cut. Remove sec- tions from the knife with a soft brush, and wash them thor- oughly in water to remove the gum and sugar; the staining is proceeded with as for other sec- tions. Remarks on the Foregoing Processes. — For small pieces of tissue the paraffin method is best; thinner sections can be cut, and the method of cement- ing them on the slide makes the handling most convenient. It is commonly stated that large blocks can not be sectioned by the paraffln method; this is true in part only. A specimen 0.5 cm. in thickness and 2 cm. square may be infiltrated thoroughly, and, under favorable conditions, with a good modern microtome, should yield sections not over 5 // thick, and in skilled hands they may be cut even thinner. For large specimens, such as an eye, and for tissues from the brain, spinal cord, or larger nerve-trunks, celloidin is to be preferred. After using the freezing method to a very large extent for about ten years, the author is thor- oughly convinced that it is not to be relied upon. The ice crystals that 1 Since the publication of the last edition of this manual the writer has known of considerable difficultv due to softening of the celloidin when preserved in cedar oil. The cause of this unfortunate complication was not at first discovered. It wotild appear that the success of the method depends upon the quality of the cedar oil. Mayer has recently informed Harris that cedar oil prepared by Schim- mel did not in the least affect the celloidin. Fic. 45. L ID Wl TH E06£ GROUND TO f/T /J_ -Dish for Removing Paraffin and Corrosive Sublimate and for Dehydrating. May also be used for staining, and for the same purposes as the Stender dish. After the sections are cemented on the slide the sUdes are placed back to back and shpped down in the groove, as shown at B at the bottom of the dish. If the slides are thin, the dish \n]l hold ten at one time. IIISTOLOCIC MKTIIODS, 4;; form in freslily frozen tissue break u]) tlie cells and p^'wc results that may mislead the most exjjerieneed investigator. The distortion of structure incident to the use of congelation masses, their maceratinj^' j)ro|jerties, and the difhculty in removing the infiltrate, have led me to give tliem up entirely for laboratory work; only the crudest kind of jjathologic work can he performed by the freezing and congelation methods at present at our disposal, and the results are always oj)en to criticism. STAINING AND MOUNTING. General Remarks.- As a rule, it is best for the student to work with one stain until he is familiar with it; and l)efore combining two or more stains it is best for him to familiarize himself with the action of each stain when used alone. The student thould remember that there are two principles involved in staining: (i) When a stain shows unusual selectivity in certain bodies, such as cell nuclei, it is allowed to act long enough to color the desired bodies only; its action is then stopped and the ^preparation of the mount continued. (2) The stain is permitted to act until everything that will receive the color is stained, and then some agent is ap])lied that differentiates certain elements by removing the stain from other structures. Thus, acid alcohol is ui-ed to differentiate in carmin staining, and water after hematoxylin. Alco- hol or water, either of which may be used with or without acidulation, are also used to differentiate with the anilin dyes. The objection to examining sections unstained is that no one structure is prominent; and if everything in the section be uniformly colored, nothing is gained by the staining. For this reason differentiation is more or less appli- cable to all stains. After differentiation, or in some instances simul- taneously with this ])rocess, dehydration is necessary in order to pro- ceed with the next step — clearing the section. The jjrocess of clear- ing is necessary in order to examine the section by transmitted light. Clearing aLso makes the a])])lication of a permanent medium, such as xylol balsam, possible. The clearing agents mentioned in the preceding and following pages are not all applical^le under all circumstances. The l)est clearing fluids are xylol, cedar oil, creasote, and possibly one or two other agents having more or less special uses. Carmin and Hematoxylin. — The two stains most fre(]uently used in laboratory work are carmin and hematoxylin. Strongly alkaline stains, such as lithium carmin, are no longer to be commended; the same is true of bulk staining. The car)iiiii most useful in the labora- tory is Orenacher's alcoholic borax-carmin: . I li ••lii-li, Kuril \ I amiiii Carmin (best No. 40). Borax Mix thoroughly, i)ulv«.Tizc' in a mortar, and add 100 part-s of water; boil for half an hour: add an er|ual bulk of seventy ]>er eent. alcohol; .set aside for one week, and then filter. To stain, add enough of the stain to the section on the slide al)un- dantlv to cover it, and allow it to act for from five to ten minutes or 46 TECHNIC. longer. Drain off the excess of stain, wipe around the section with paper or soft cloth, and apply acid alcohol. Acid Alcohol. Hydrochloric acid i part. Water, 29 parts. Alcohol ' 70 The section, as soon as the acid alcohol is applied, turns from a purpHsh-red to a light crimson, and becomes more nearly trans- parent; it is then washed in strong alcohol, the excess wiped from around the section, and the latter is covered with creasote. The alcohol dehydrates and removes the acid, which is the differentiating agent, and the creasote renders the section clear for examination by trans- mitted light. As soon as the section is clear remove the excess of creasote, apply a drop of balsam, and cover with a thoroughly cleansed cover-glass; label the section. It will now keep in- definitely. One of the best carmin stains is Mayer's carmalum. This is made by dissolving i gm. of car- minic acid and 10 gm. of alum in 200 c.c. of distilled water, using heat if necessary. In order to preserve the solution add o.i per cent, of salicyhc acid, or 0.5 per cent, of salicylate of sodium. The solution is clarified by decanting or, better, by filtration. The great advantage of this solution lies in the fact that it is almost impossible to overstain with it, and by careful washing and differentiation practically all interme- diate degrees of staining can be obtained. It may be differentiated in acid alcohol, as already directed for borax-carmin, or, if the alcohol used for the sub- sequent dehydration be strongly tinted by the addition of picric acid, the combined action of the two stains (the carmin being a nuclear stain and the picric acid a protoplasmic stain) will afford one of the best general stains found in the laboratory. Picric acid may be used in the same way with borax-carmin, but the result is not so satisfactory. Hematoxylin Staining. — The classic form of this stain is Dela- field's, made as follows: Dissolve 4 gm. of hematoxylin crystals in 25 c.c. of strong alcohol; add this solution to 400 c.c. of a cold, filtered, satu- ratec' -aqueous solution of ammonia alum; expose to light and air for several day Filter, and add glycerin 100 c.c. and methyl alcohol 100 c.c. Allowed to stand in the light, with the bottle loosely corked, this mixture turns dark purple, almost black; it should then be filtered and kept in tightly stoppered bottles. For use it should be much diluted: the amount of' dilution must be determined for each lot. varying with the Fig. 46. — Dropping- bottle with Barnes's Dropper, Which Closes THE Mouth of THE Bottle Like A Rubber Stopper. These bottles are usually of one ounce capa- city, and are con- venient for holding stains and staining reagents. Fig. 47. — Proper Size Labels for Label- ing ' Microscopic Slides. HISTOLOGIC MKTIIODS. 4- dcgree of oxidation ami with the aj,'e of the stain. If made with distilled water, and provided tliat all vessels and containers are kejjt chemically clean, this stain will keep for years. The objection to this stain lies in the fact that it requires time for ripening, and hence cannot be made antl used at once. Harris overcame this difficulty by artificially oxidizing the hematoxylin into hematein. Harris's hematoxylin is jTrepared bv dissolving one gram of hematoxylin in lo c.c. of alcohol and adding the resulting solution to 200 c.c. of distilled water in which 20 gm. of am- monia or potassium alum have previously been dissolved. The tluitained by this method are sharp, and the •■ " • di protoplasmic tints are beautifully transparent. For routine work I am unfamiliar with any contrast s» o that suggested In- Van Gieson. Various strengths ha\ ■ mended, but the following, which may be further diluted wiih picric, acid if necessary, will be found satisfactory: Van GUton't Solution. Acidfuchsin, r percent, aqueous solution. . Picric acid, saturated aqueous solution, . Water. . 48 TECHNIC. Sections are stained deeply with hematoxylin, washed in water, treated with the above solution for from one to four or five minutes, rapidly dehydrated, cleared, preferably in xylol, and mounted in xylol balsam. The connective tissue is red or pinkish-red, the cell protoplasm of a yellow- ish tinge, and the nuclei a dark brownish or reddish-purple. In properly fixed preparations containing nerve-fibers the axis-cylinders stain red. Anilin Dyes. — In addition to the use of these agents for staining bacteria, thev have become important and useful adjuvants in certain microchemic reactions, which will be referred to under special headings throughout the book; and also for general stams. For practical pur- poses the anilin dyes may be divided into two groups: 1. Basic group, in which the staining property is due to the base present in the compound. 2. Acid group, in which the staining property is due to the acid principle. The basic colors are, as a rule, sharp nuclear stains, while the acid dyes stain, more or less diffusely, the protoplasm in the cell. As a rule, the dyes are used as concentrated solutions (i) in water; (2) in five per cent, carbolized water; (3) in thirty to sixty per cent, alcohol, preferably about fifty per cent. Under some conditions the dyes seem to act best if the solutions are rendered faintly alkahne; or at other times, faintly acid. The alkalinity is usually secured by the addition of a very small quantity of carbonate of potassium, and the acidity by an extremely dilute solution of acetic, formic, or hydrochloric acid. The basic anihn dves commonly used are safranin, fuchsin, methylene-blue, thionin, eentian-violet, toluidin-blue, etc. The acid stains mostlv used are eosin, orange G, acid fuchsin, etc. The following formulas and methods are introduced as examples, and after the student has familiarized himself with the technic given, he may applv the knowledge so obtained to staining with other and similar anilin dyes.' Safranin is a most excellent nuclear stain. The following formulas are to be recommended : Saturated solution of safranin in water, heated to 75° C. ; after thorough saturation, filter; stain from two to five minutes to twenty- four hours, depending upon the tissue, length of fixation, etc. ; wash in water, differentiate and dehydrate simultaneously in alcohol, clear in xylol, and mount in xylol balsam. A mixture composed of one part of the above solution of safranin and one part of a saturated alcoholic solution of alcohol-soluble safranin makes a satisfactory stain, and may be used in the same way. Methyl-violet. — One or two per cent, solution in water. Stain from two to five minutes or longer, and treat in the same manner as already given for safranin. Polychrome Methylene-Blue- (Unna) is a most acceptable stain for 1 One of the great difficulties with anilin dyes is the inconstancy of their com- position and the unreliability of many samples placed on sale. For this reason it is recommended that in purchasing the anilin dye the student should always specify the make of Griibler. 2 This stain resembles, when diluted, Lofller's alkaline methj-lene-bhie, the formula of which is as follows: Saturated alcoholic sokition of methylene-blue 30 c.c. Potassium h3^drate (o.oi percent, aqueous solution),. . 100 c.c. Mav be used for staining tissues, but is more useful in bacteriologic work. HISTOLOGIC MIvTHOI)^ routine laboratory work. Although the formula i"r iiiaKin;; ims ny i easil)' accessible, satisfaction can best be obtained by jjurchasin^' the })repared stain from Grubler. ( )ne ])art of the dye to two or three parts of water is the best strength. Sections shoukl be stained for fifteen minutes to several hours, washetl in water, dehydrated, cleared in xylol, and mounted in balsam. The most beautiful results are obtained by glvcerin-ether or styrone differentiation, both of which are described below. Contrasts with eosin may be obtained by staining in a o.i per cent, aqueous solution of water-soluble eosin; wash lightly with water and transfer to the polychrome blue; the latter tends to remove the eosin, and hence success depends on accurately judging the time neces- sary for immersion in the polychrome solution. Nothing but patient experimentation can accurately inform the beginner, but success rej)ays him U)r the time and labor expended. Toluidin-blue. — Dissolve one part of the dye in loo parts of a five per cent, solution of carbolic acid in water; stain from hve to ten minutes to twenty-four hours, differentiate and dehydrate in alcohol, clear with cedar oil, and mount in xylol balsam. Ziehl's Carbolfuchsin. — Rub up i gm. of powdered fuchsin with lo c.c. of alcohol in a glass mortar; dissolve 5 gm. of crystalline carbolic acid in 100 c.c. of distilled water; mix the tw^ solutions and the stain is ready for use. The stain may be prepared by the addition of 10 c.c. of a saturated alcoholic solution of fuchsin to 90 c.c. of a five per cent, aqueous solution of carbolic acid. Stain sections two to five minutes to several hours; differentiate and dehydrate in alcohol, clear in clove oil or xylol, and mount in xylol balsam. As a rule, sharpness of nuclear stain is obtained by overstaining, followed bv careful differentiation, which must be stopped at a certain time; the best results are obtainable after repeated experiments and manv failures. Alcohol as a differentiating agent does not give the best results, nor is the differentiation in alkaline or faintly acidulated water ideal. Two of the most satisfactory differentiating agents with which the writer is familiar are glycerin-ether and styrone. The glycerin-ether mixture (Unna) is obtained from Grubler; the proper dilution is one part of the agent to fifteen of water. Sections are stained rather deeply in Unna's polychrome methylene-blue or in carbol-toluidin-blue, rinsed in w^ater, and covered with the diluted glvcerin-ether mixture. At first the dye comes out in clouds; later, differentiation progresses more slowly. The exact point at which to arrest the differentiation can be learned by experience only. In order to arrest the action of the glycerin-ether the excess is poured off, the section washed in water followed by rapid dehydration and clearing in xvlol or cedar oil, and finally balsam. Many bacteria are beautifully stained bv this method. Styrone is a solid, camphor-like body at a low temperature; at the ordinarv room-temperature it assumes a syrupy consistence. It is a differentiating fluid that also acts as a clearing agent and is superior to other differentiating agents in that the tissues may be watched under the microscope without a cover-glass, during the process of differentia- tion. In order to aj>ply it, the section, stained as already advised for glvcerin-ether. is hastily washed in water, followed by alcohol, and the stvrone is at once applied. The styrone first applied becomes cloudy. 5° TECHNIC. deeply dyed, and is poured off; fresh styrone is added, and the shde is placed' on the stage of the microscope. As soon as the differentia- tion has become satisfactory the styrone is washed off with cedar oil, the application of the latter agent being continued until all differentia- tion has ceased ; the cedar oil is then removed and xylol balsam and a cover-glass are apphed. In clearing sections stained by basic anilin dyes disaster commonly follows the application of creasote. Xylol is considerably better, but the best results are obtained by the use of cedar oil, which acts slowly and must be given time; gentle warming hastens the clearing-, but is rarely necessary if the dehydration has been complete. Eosin may be used with either of the nuclear stains previously given. It is particularly useful with the toluidin-blue. Eosin, either as a satu- rated solution in water of the form soluble in that medium or saturated solution of eosin in alcohol, using the form soluble in that agent, may be used as contrast stains before or after the toluidin-blue or methylene-blue ; as both of these agents are discharged by eosin solu- tions, it is possibly better to stain first with eosin, rinse in water, and apply the nuclear stain afterward. If the eosin be used after the nu- clear stain, it should not be allowed to act too long, otherwise the nuclear stain may be discharged. As eosin 'acts as a differentiating agent, when used after the nuclear stain, care and experience are necessary to secure the best results. After the use of eosin, dehydration in alcohol and clearing in cedar oil are recommended. For the use of eosin as a contrast stain with hematoxylin, see page 47. For the use of picric acid for the same purpose and with carmin, see page 46. THE MICROSCOPE. A Desirable Laboratory Microscope. — Figure 48 illustrates a stand useful in a pathologic laboratory. The horseshoe base gives solidity by its long arms and great weight. To this base is attached the upright, which supports the superstructure; the stand should be handled by this piece entirely, never grasping the parts above in moving the microscope, as such a procedure is hkely to injure the adjustments. At the upper termination of the upright is the joint for inclining the microscope for convenience in working. Running to the front from this joint is the stage upon which the slide is placed for examination; clips are shown for retaining the slide in position. Beneath the stage are the substage mountings, consisting of diaphragms for lessening the hght, condenser for increasing the rays' intensity, and a mirror for reflecting the light upward through the optic axis of the instrument. These parts are adjustable by lateral movement, by rack, pinion, and screw motion. Behind the inclination joint, and above the stage, what is known as the upright arm rises; at its upper part is placed the fine adjustment, worked by a milled thumb-screw. Passing off in front of this upright arm is the horizontal arm, to which is attached the coarse adjustment by rack and pinion moved by the milled heads shown at both sides. The tube carrying the optic parts is attached to the horizontal arm by the rack and pinion coarse adjustment. The tube is so made that it may be drawn out to a standard length. At the upper end of the tube is the eye-piece; at the lower end, the objec- HISTOLOGIC MKTIIonS. live. In the laboratory instrument, when, for any reason, an oil-im- inersion objective may not be desired, two objectives (a 1( of an inch and a \ or ,; of an inch) are mounted on a double nose-piece, l)y means of which either objective may be brought into vise. In bactcriologic examinations in which an oil-immersion lens is indispensable, three objectives are mounted on a triple nose-piece, as shown in the cut. (Fig. 48.) In nearly all cases the examination should bcgiti with the lower power, fol- lowed. // )icccssary. In- the higher power. To Use the Microscope. — The instrument is placed in front and slightly to one side — usually the right side — of the observer; the student is advised to use the instrument with the stage hori- zontal, that is. without using the inclination joint. During the day, northern light or light from white clouds is preferable ; if the window is exposed to the direct rays of the sun. a piece of thin tissue-paper is pasted over the glass, or the glass may be frosted or painted ; direct sun- light should never be used ex- cept for photomicrography. If an artificial light is to be used, the microscope is placed about thirty centimeters from the light, and to one side, so that neither the heat nor the direct rays from the light will be thrown in the face or eyes of the ob- server. The best artificial light is afforded by the Welsbach burner or a thirty-two candle- power incandescent burner with a thoroughly frosted globe. While for convenience in gen- eral work the stand may be tilted, when examining mounts of liquids, urine, hanging-dro]^ culture, etc.. the stand must be upright so that the .stage is perfectly level. Place the slide on the stage and looselv secure it by the clips; so adjust the mirror as to illuminate the center of the held ; without placing the eye • eve-piece, rack the objective down until it almost touches the then look into the instrument and perfect the illumination by adjust- I'lG. 4S.- -MlCR, hLK >OR CiFNKRAL PATHO- LOGIC ANU Ba^-IERIOLOCIC Work. Draw-lubf. c. Rack, d a. (Jcular or eye-piece, h. Milled head of pinion nrnving ttv -• \- <> pinion (c and J) toRithcr .ire i mcnt. e. Miirosropic ml" wiiich the line adjust tn ■ - nose-piece or revolver h: in Ihe alxjve instrut- which in turn may lie t »'. Stage on the upjx-r holding the «liil.- dtiri' phragm in ' ' variation ii fondcnson. Such an objection need not be answered here, since those who hold it can not know of the advances made by the experimental methods of study, or are not in that condition of mental receptivity necessary to appreciate scientific truths. The results attained by the investigation of disease in lower animals have probably done more to alleviate suffering in them than in man. Comparative pathology— ^the study and comparison of morbid proc- esses in the lower animals and in man — also affords ample opportunity to obtain information as to the causes of, and alterations in, disease. In all pathologic study, to attain the best results the statistical method must be used to a certain extent. The collection of a large number of cases, with a careful analysis of recorded data, can but yield valuable conclusions. The constancy of associated lesions — as, for example, the association of certain nervous and nutritive phenomena with removal or disease of the thyroid gland — often indicates a path for investigation that may terminate in a happy solution of some obscure problem. The study of diseased organs or tissues postmortem or after operative removal from the body need hardly be mentioned as a most fruitful source of knowledge concerning morbid processes. In addition to the above methods, it can not be an error thoroughly to study morbid processes during life. Therein lies the strength of the science. The symptoms of a disease are but expressions of the lesions — the morbid physiology* induced by chemic, mechanical, or struc- tural alterations. From symptoms it is possible in many cases to infer the character of the tissue changes, or, by studying the alterations in the normal chemistry and structure, the symptoms may be explained. He is far at sea who believes that the study of pathology begins and ends with the postmortem. CHAPTER I. THE ABNORMAL; MALPOSITION; MALFORMATION. General pathology comprehends those variations in structure and function that may attack any organ. It is the study of morbid processes independent of their location, while special pathology is the study of diseases of organs independent of the same disease occurring elsewhere than in the organ under consideration. In order to appreciate the abnormal it is necessary to have some definite idea of the normal. Information with regard to health is ob- tained by studying individuals or organs not manifesting disease and considering as normal that condition which is commonest. Difficult v is encountered in accurately judging the limitations within which modi- fication of structure and function may be regarded as physiologic. In most instances, however, the morphologic and physiologic boundaries of the normal are sufficiently circumscribed to permit a readv recogni- tion of conditions that pass beyond their domain. Any deviation from the normal must be recognized as belonging to the malpositions, mal- formations, or diseases. MALPOSITIONS. Malposition is misplacement of an organ from that position in which it is most commonly found, or any alteration of its relation to other organs; it is a mal-posed structure. The heart may be rotated on its axis and not occupy the normal relation to the surrounding tissue, and still the heart may be in place; so that malposition implies either that the organ is not in place, or that, being in place, its parts do not bear their normal relation to adjacent structures themselves normallv located. Congenital malposition may consist in the perpetuation of fetal characters, and not infrequently is associated with malformation; thus, failure in closure of the body cleft anteriorly, particularly at the um- bilicus, may permit a viscus wholly or in part to lie outside the abdom- inal cavity ; fenestra in the diaphragm may allow the heart to descend into the abdomen or one or more abdominal organs to rise into the thorax (congenital diaphragmatic hernia). Organs that develop in one position and later normally acquire another may, for some reason, fail to make the requisite migration and persist through adult life in a posi- tion more or less normal in the embryo; a kidney may fiom this cause lie near the median line or the testicle remain in the abdomen. An in- teresting form of congenital malposition is that represented by ectopia of parts of organs, although the term is also used for entire organs occupying abnormal positions. Some organs show the most extraordinarv ten- 58 THE abnormal; malposition; MALIdkMATION. 5Q dencv to partial or even complete ectopia; thus adrenal tissue may be found in the hver, spleen, neighborhood of the ovary or testicle, and IS not infrequently present in the kidney, usually the cortex. Aberrant pancreatic lobules occur in the stomach, duodenum, jejunum, and less frecjuentlv in the ileum; gastric glands may be present in the duo- denum or in the esophagus; fragments of thyroid may be distributed along the course of the thyroglossal duct, at the base of the tongue, or within the thoracic cavity. The cause of these various forms of ectopia is more or less obscure; the usual explanation, that they de- pend upon incarceration of growing cells in abnormal localities, is little more than a restatement of the primary facts. It should be remem- bered that such ectopic tissues are particularly prone to manifest tumor formation; misplaced testes not infrequently become sarcomatous or carcinomatous; lingual, tracheal, and mediastinal goiters develop from ectopic thyroid tissue, and the relatively frequent tumor called a hyjjer- nephroma" is the result of neoplastic activity in ectopic adrenal tissue. Congenital malpositions may correct themselves or be corrected by the surgeon, although their tendency is to persist; an umbilical or in- guinal hernia of congenital origin may be replaced, an abdominal testis mav. bv operative procedure, be brought to its normal position; a mesial kidney or a right-sided heart of congenital origin will probably never occupv the position of the normally posed organ. Acquired malposition may result from congenital defects, disease, trauma, etc. Imperfect closure of the abdominal parietes at the um- bilicus, inguinal or femoral outlets, permits the occurrence of hernia at these points; when the muscle of one-half of the diaphragm fails to develop, the absence of contractile power, the elasticity of the lung, and the higher abdominal pressure lead to eventration, the diaphrag- matic arch of that side rising almost to the apex of the thorax, permit- ting abdominal organs to lie within the chest cage but not in the thoracic cavity. Disease may in a number of ways cause malposition; enlarged or- gans mav bv their increased bulk or weight drag from normal attach- ments; this' is especially true of the spleen, kidney, and stomach, and to a lesser degree of the pancreas, transverse colon, and gall-bladder. Disease mav also alter the lines of pressure and displace organs not themselves diseased. The heart is pushed to the left and the liver displaced downward by gas or fluid accumulations in the right pleura or massive solid or cystic growths involving that structure or the lung. Acquired malposition may result from loss of normal support by reten- tive structures. Wasting of the abdominal wall favors prolapse of the contained viscera (visceroptosis). The alteration in pressure throws unusual stress upon the structures normally retaining liver, spleen, and kidnevs in place, as a result of which change these organs are prone to prolapse. Loss of support in the pelvic floor permits of uterine displace- ments. Organs mav be pulled out of place by the contraction of fibrous tissue. In chronic interstitial pneumonia when the involved lung is firmlv attached to the chest wall contraction of the newly formed hbrous tissue tends to pull the heart and other mediastinal tissues toward the affected side. Inflammatory conditions may perpetuate inalpositions due to other causes; adhesions may render reducible hernias irreduc- ible or mav eventuallv bind in its new position an organ but tempo- 6o GENERAL PATHOLOGY. rarily displaced. One organ wandering from its normal position mav lead to displacement of another; the prolapsed spleen may carry with it the tail of the pancreas; the transverse colon displaced downward may drag upon the stomach and the dilated or prolapsed stomach may in turn displace the colon. Trauma may in a number of ways give rise to malposition; falls with sudden arrest, or blows in the renal region may loosen normal attachments and be followed by displacement of the kidney. Wounds m the abdominal wall may cause hernia primarily, or secondarily by imperfect healing and relaxation of the cicatrix. Malpositions due to fractures of bone and misplacement of fragments, or dislocation of ar- ticular surfaces — constituting both a malposition and an abnormal formation — are usually referred to as deformities, although to the lav- man malposition, malformation, and deformity are essentiallv the same. It will be recognized from the foregoing that malposition, of itself does not constitute disease. Misplaced organs may be functionally normal; removed from the body, a right-sided heart may differ in no respect from a normally placed organ. As already intimated, ectopic tissues are prone to disease, and frequently manifest more or less per- version of function; it is usually maintained that abdominal testes produce no spermatozoa. In most other organs, however, function is manifestly adequate. Malposition not infrequently subjects the affected tissue to influences not exerted upon the same organ in its normal posi- tion; the floating spleen, kidney, or liver is more liable to injury than a normally placed organ. Abnormal position not infrequently subjects nerves, vessels, and ducts to unusual stress; traction on the splenic pedicle obstructs the vein and favors congestion, torsion of the pedicle may arrest the circulation. The ureter of a floating kidney is not infrequently compressed, angulated. or kinked, therebv impeding the outflow of urine. MALFORMATIONS. 1 Malformation is a deviation in structure and development from that most commonly found. A malformed structure is not neces- sarily diseased, — although it may have resulted from disease and mav manifest a tendency to various pathologic processes which properly may be called diseases. Acquired malformation is commonly called de- formity, although the liver distorted by the corset is usually termed a malformed organ. In some ways maldevelopment is preferable to malformation; the former term is usually applied to abnormal condi- tions depending upon developmental errors, and as most malformations properly so called have this origin, the two terms tend to become essen- tially synonymous. Teratogenesi's. — While the causes of malformation may, in certain instances, be evident, a large percentage of cases are inexplicable by any facts at present in our possession. It must be apparent that any essential abnormality in germ or sperm cell, or both, necessarily tends to abnormality in the evolved product of their union. Abnormal in- fluences brought to bear upon the impregnated ovum must necessarily 'Consult Ballantyne, "Manual of Antenatal Pathology and Hygiene," "The Enibrj'o," 1Q05. Till-; AHNOKMAL, M ALroSlTK)N ; M AI. KOkM ATlON . ' : inodif)- Its growth. It is therefore apparent that certain causi be regarded as iiitrinsiL — having their origin in the cells from which the new being springs; other, causes are extrinsic, depending upon in- tiuences acting upon what might be called a normally disposed develop- mental process. An important member of the intrinsic causes is in- heritance; web-tingers (syndactylism), short, stunted fingers or toes (perodactylism), harelip, and minor abnormalities arc frecjuently trans- mitted by one or the other parent. A mother may bear normal chil- dren by one husband while by another the offspring may show malforma- tions transmitted by the father. When a malformation is traceable to a remote rather than an immediate ancestor, the condition is called atovisDi, or reversional heredity. Closely allied to the transmi.ssion of gross morphologic defects must be classed the undemonstrable cellular or cytochemic peculiarities of tissue which create tendencies to dis- ease or abnormal susceptibilities, to which reference will be made later. In the chick it has 1)een demonstrated that such external influences as temperature change, shellacing the egg, frequent shaking, and ab- normal posture may determine malformation in the ofTsjjring. The human embryo in ectopic pregnancies is not infretjuently malformed. Abnormal pressure upon and abnormal position of the extremities may modify the shape of the bones and soft parts. Insufirtcient amniotic fluid especially subjects the fetus to external influences. Adhesions between the embryo and the amnion and abnormal pressure exerted by the membrane may also be causes. Pressure exerted by the hand and chin on the thorax may interfere with development of the sternum. The funis wrapped around an extremity may by pressure cause ampu- tation. It has been alleged that increased abdominal or uterine pres- sure may produce malformations; Ballantyne does not hold this view, nor does he look with favor upon the often expressed opinion that mal- formation of one twin may be due to pressure exerted by the other. These and similar influences are called the cxtri)isic causes of malforma- tion. The earlier these influences become operative, as a rule, the more marked the resulting malformation. Nosologic or Pathologic Theory. — Disease of the fetus may g^ive rise to important developmental