Saunders' (juestion Compends 
 
 Essentials of 
 Bacteriology 
 
 M.V.BALL. M.D, 
 
 Seventh Edition 
 
New (9th) Edition 
 
 MEl 
 
 " Thi 
 
 A Q>mplet< 
 Pharm 
 togeth< 
 Veins, 
 DiseasH 
 of Trc. 
 Amcfic 
 bound 
 $5.50 I 
 
 It cont 
 
 This e< 
 assistants ha 
 the-minute < 
 medical lex 
 words, and 
 two-score ot 
 
 " In purst 
 dozen dictiona 
 with short, c< 
 Wood, M. D., 
 
 "The Am 
 of such conve 
 M. D., Pro/e 
 
 
 MEMCAL ^S€]nI©©L. 
 LUISMAlRlf 
 
 ! i 
 
 RY 
 
 rds 
 
 Dentistry, 
 branches; 
 s, Nerves, 
 Tables of 
 Methods 
 or of the 
 79 pages, 
 lb index. 
 
 nimum 
 
 i of expert 
 Jr,down-to- 
 r any other 
 II the nezv 
 en, it has 
 
 ome ten or a 
 English words 
 ' — Casey A. 
 
 )tton up and 
 A, Kelly, 
 
 e, Phik. 
 
 London: 9, Henrietta Street^ Covent Garden 
 
New (lOth) Edition 
 THE 
 
 AMERICAN POCKET 
 
 MEDICAL DICTIONARY 
 
 EDITED BY 
 
 W. A. NEWMAN DORLAND, A. M., M. D., 
 
 Editor " American Illustrated Medical Dictionary" 
 
 HUNDREDS OF NEW TERMS 
 
 Bound in Full Leather, Limp, with Gold Edges. Price, $t.25 net; 
 with Patent Thumb Index, $1.50 net 
 
 The book is an absolutely new one. It is not a revi- 
 sion of any old work, but it Jias been written entirely anew 
 and is constructed on lines that experience has shown to be 
 the most practical for a work of this kind. It aims to be 
 complete, and to that end contains practically all the terms 
 of modern medicine. This makes an unusually large vocabu- 
 lary. Besides the ordinary dictionary terms the book contains 
 a wealth of anatomical and other tables. This matter is 
 of particular value to students for memorizing in preparation 
 for examination. ' 
 
 " I am struck at once with admiration at the compact size and attractive ex- 
 terior. I can recommend it to our students without reserve." — James W. Hol- 
 land, M. D., of Jefferson Medical College. 
 
 ** This is a handy pocket dictionary, which is so full and complete that it puts 
 to shame .some of the more pretentious volumes." — Journal of the American 
 Medical Association. 
 
 " We have consulted it for the meaning of many new and rare terms, and 
 have not met with a disappointment. The definitions are exquisitely clear and 
 concise. We have never found so much information in so small a space." — 
 Dublin Journal of Medical Science. 
 
 "This is ^ handy little volume that, upon examination, seems fairly to fulfil 
 the promise of' its title, and to contain a vast amount of information in a very 
 small space. ... It is somewhat surprising that it contains so many of the rarer 
 terms used in medicine." — Bulletin Johns Hopkins Hospital, Baltimore. 
 
 W. B. SAUNDERS CO., West Washington Square, Phila. 
 London: 9, Henrietta Street, G)vent Garden 
 
^ 
 
 
 %'\f ' 
 
 c/^ 
 
 ^ 
 
ESSENTIALS 
 
 OF 
 
 BACTERIOLOGY 
 
Since the issue of the first volume of the 
 Saunders Question=Compends, 
 
 OVER 375,000 COPIES 
 
 of these unrivalled publications have been sold. 
 This enormous sale is indisputable evidence 
 of the value of these self-helps to students 
 and physicians. 
 
Digitized by the Internet Arcinive 
 
 in 2007 with funding from 
 
 IVIicrosoft Corporation 
 
 http://www.archive.org/details/essentialbacteriOOballrich 
 
Ocular 
 
 Graduated 
 Draw-tube 
 
 Coarse Adjuster 
 Fine Adjuster 
 
 Perforated 
 Handle 
 
 Objectives and 
 Nose-piece 
 
 Snbiitaqe with 
 Diaphragm 
 and Condenser 
 
 BACTERIOLOGIC MICROSCOPE. 
 
SAUNDERS' QUESTION-COMPENDS. No. 20 
 
 ESSENTIALS 
 
 BACTERIOLOGY 
 
 CONCISE AND SYSTEMATIC INTRODUCTION TO THE 
 STUDY OF BACTERIA AND ALLIED MICROORGANISMS 
 
 t * a * ■ 
 
 
 professor' of' pathology, NBW YORK MEDICAL COLLEGE AND HOSPITAL FOR 
 
 WOMEN, NEW YORK CITY ; MEMBER OF THE ACADEMY OF NATURAL 
 
 SCIHKCBS OF PHILADELPHIA; FORMERLY INSTRUCTOR IN 
 
 BACTERIOLOGY AT THE PHILADELPHIA POLYCLINIC. 
 
 Assisted By 
 
 PAUL G, WESTON, M. D. 
 
 PATHOLOGIST STATE HOSPITAL FOR INSANE AT WARREN, FA. 
 
 SEVENTH EDITION, THOROUGHLY REVISED 
 
 With 118 lUustrations, some in Colors 
 PHILADELPHIA AND LONDON 
 
 W. B* SAUNDERS COMPANY 
 
 J9I8 
 
Copyright, 1891, by W. B. Saunders. RepW.jted October, 1892. Revised, reprinted, 
 and recopyrighted May, 1893. Reprinted June, 1894, Revised, reprinted, and re- 
 copyrighted November, 1896. Reprinted October, 1898. Revised, reprinted, 
 and recopyrighted March, 1900. Reprinted May, 1903. Revised, reprinted, 
 and recopyrighted August, 1904. Reprinted October, 1905, and 
 August, 1905:. - Re<'ised, entirely resgt. reprinted, §nd rec9p_yrighted 
 September, -19081 R«printeid Anju^t, l9io'« ^e^'isen, entirely 
 reset, rv-'prtoteii, a«id<.iecopy-ig4i{cd De'?em|)e'-, 1919. 
 c , , ,Repryite4 January, 1914 ^ 
 
 Copyright* i9i3,*by W. ET. launders Company. 
 
 Reprinted July, 1916 
 
 Reprinted May, 191 8 
 
 PRINTED IN AMERICA 
 
 PRESS OF 
 SAUNDERS COMPANY 
 PHILADELPHIA 
 

 (^/O- 
 
 PREFACE TO THE SEVENTH EDITION 
 
 This book has undergone a complete revision and many 
 of the chapters have been rewritten in their entirety. Those 
 which relate to immunity and infection have been carefully 
 edited by Dr. Paul G. Weston, Pathologist at the State 
 Hospital, Warren, Pa., who has also furnished the article 
 on the Wassermann reaction. The author is likewise in- 
 debted to him for valuable aid in other portions of the re- 
 vision. 
 
 The author realizes that compends of this nature must 
 necessarily suffer in comparison with the larger and more 
 elaborate works, and he trusts that the reviewers will bear 
 this in mind in their criticisms. 
 
 When this book first appeared in 1891 it was one of the 
 first American publications on the subject, and only a few 
 text-books had been issued in other countries. Although 
 since then a great many excellent treatises have appeared, 
 there still remains a place for this compend, and hence this 
 new edition. The author hopes that he has succeeded in incor- 
 porating all the newer established facts in bacteriology and 
 in eliminating all that is obsolete and no longer in use. 
 
 M. V. Ball. 
 
 3577<^ 
 
PREFACE TO THE FIRST EDITION 
 
 Feeling the need of a Compendium on the subject of 
 this work, it has been our aim to produce a concise treatise 
 upon the Practical Bacteriology of to-day, chiefly for the 
 medical student, which he may use in his laboratory. 
 
 It is the result of experience gained in the Laboratory 
 of the Hygienical Institute, Berlin, under the guidance of 
 Koch and Frankel; and of information gathered from the 
 original works of other German, as well as of French, bac- 
 teriologists. 
 
 Theory and obsolete methods have been slightly touched 
 upon. The scope of the work and want of space forbade 
 adequate consideration of them. The exact measurements 
 of bacteria have not been given. The same bacterium varies 
 often much in size, owing to differences in the media, staining, 
 etc. 
 
 We have received special help from the following books, 
 which we recommend to students for further reference: 
 
 Mace: Traite pratique de Bacteriologie. 
 Frankel: Grundriss der Bakterienkunde. 
 Eisenberg: Bakteriologische Diagnostik. 
 Crookshank, E. M.: Manual of Bacteriology. 
 Gunther: Einfiihring in das Studium der Bacteriologie, etc. 
 WooDHEAD and Hare: Pathological Mycology. 
 Salmonsen: Bacteriological Technique (English transla- 
 tion) . 
 
 M. V. BAUL. 
 11 
 
CONTENTS 
 
 PACK 
 
 Introduction 17 
 
 PART I 
 
 GENERAL BACTERIOLOGY 
 
 Chapter I — Structure and Development of Bacteria ... . 21 
 
 Chapter II — Biologic and Chemic Activities 26 
 
 Chapter III — Infection 30 
 
 Chapter IV — Immunity 34 
 
 Chapter V — Methods of Studying Bacteria — Microscope 43 
 
 Chapter VI — Methods of Studying Bacteria (Continued), 
 
 Solutions and Formulas for Staining 47 
 
 Chapter VII— General Method of Staining Specimens 54 
 
 Chapter VIII — Special Methods of Staining and Modifica- 
 tions „ 58 
 
 Chapter IX — Cultivation of Bacteria 62 
 
 Chapter X — Preparation of Nutrient Culture-media .... 67 
 
 Chapter XI — Inoculation of Culture-media 78 
 
 Chapter XII — Cultivation of Anaerobic Bacteria 82 
 
 Chapter XIII — The Growth and Appearances of Colonies ... 87 
 
 Chapter XIV — Animal Inoculation 91 
 
 Chapter XV — Bacterins (Vaccines) 95 
 
 PART II 
 
 SPECIAL BACTERIOLOGY 
 
 Chapter XVI — Some Common Bacteria Slightly Pathogenic. 97 
 
 Bacterium Prodigiosum 97 
 
 Bacillus Mesentericus Vulgatus 98 
 
 Bacillus Megaterium 99 
 
 Bacillus Ramosus . . . .• 99 
 
 Bacterium Zopfii 100 
 
 Bacillus Subtilis (Hay Bacillus) icx> 
 
 13 
 
14 CONTENTS 
 
 PAGE 
 
 Boas-Oppler Bacillus loi 
 
 Bacillus Violaceus 102 
 
 Microorganisms Found in Urine 102 
 
 Micrococcus Ureae 102 
 
 Spirilla 103 
 
 Spirillum Rubrum 103 
 
 Sarcina 103 
 
 Sarcina Lutea 103 
 
 Sarcina Aurantiaca 104 
 
 Sarcina Ventriculi 104 
 
 Chapter XVII — Bacillus of Anthrax 105 
 
 Chapter XVIII — Bacillus Tuberculosis and Allied Organ- 
 isms no 
 
 Other Acid-fast Bacteria 116 
 
 Bovine and Human Tuberculosis 119 
 
 Products of Tubercle Bacilli 1 20 
 
 Lepra Bacillus 122 
 
 Smegma Bacillus of Alvarey and Tavel 1 23 
 
 Bacillus of Glanders (Bacillus Mallei; Rotz-Bacillus) 124 
 
 Chapter XIX— Diphtheria Bacillus 126 
 
 Chapter XX — The Colon-typhoid Group 133 
 
 Bacillus Coli 134 
 
 Bacillus of Typhoid or Enteric Fever 135 
 
 Antityphoid Bacterins (Vaccines) 139 
 
 Differentiation Between Colon and Typhoid 142 
 
 Typhoid Bacilli from Blood 143 
 
 Paracolon or Paratyphoid Bacilli 143 
 
 Bacillus Botulinus 144 
 
 Bacillus Dysenteriae 145 
 
 Bacterium Termo 147 
 
 Bacillus Proteus Vulgaris 147 
 
 Proteus Mirabilis 147 
 
 Proteus Zenkeri 148 
 
 Chapter XXI — Cholera Bacteria 148 
 
 Spirillum Cholerae (Comma Bacillus of Cholera) 148 
 
 Chapter XXII — Bacteria in Pneumonia 155 
 
 Diplococcus Pneumoniae 157 
 
 Bacillus Pneumoniae 159 
 
 Bacillus of Rhinoscleroma 159 
 
 Bacillus of Influenza 160 
 
 Koch-Weeks Bacillus 161 
 
 Bacillus of Pertussis (Whooping-cough) 161 
 
 Bacillus Melitensis 162 
 
 Chapter XXIII — Pyogenic Cocci 163 
 
 Streptococcus Pyogenes; Streptococcus Erysipelatis 164 
 
 Staphylococcus Pyogenes Aureus 166 
 
CONTENTS 1 5 
 
 PACK 
 
 Staphylococcus Pyogenes Albus 168 
 
 Micrococcus Pyogenes Citreus 169 
 
 Micrococcus Cereus Albus 169 
 
 Micrococcus Cereus Flavus 169 
 
 Micrococcus Pyogenes Tenuis 169 
 
 Micrococcus Tetragenus 170 
 
 Morax-Axenfeld Diplobacillus of Conjunctivitis 171 
 
 Bacillus Pyocyaneus 171 
 
 Chapter XXIV — Gonococcus — Meningococcus 174 
 
 Micrococcus Gonorrhoeae 174 
 
 Allied Varieties 176 
 
 Diplococcus Intracellularis Meningitidis 177 
 
 Bacillus of Soft Chancre, Chancroid 178 
 
 Chapter XXV — Anaerobic Bacteria (Bacillus of Tetanus; 
 
 Bacillus of Malignant Edema, Etc.) 180 
 
 Bacillus of Tetanus 180 
 
 Bacillus (Edematis Maligni; Vibrion Septique 184 
 
 Bacillus Aerogenes Capsulatus 186 
 
 Bacillus Enteritidis Sporogenes 187 
 
 Bacillus Chauvei 187 
 
 Chapter XXVI — Hemorrhagic Septicemia Group 190 
 
 Bacteria of Hemorrhagic Septicemia 192 
 
 Bacillus of Chicken Cholera 193 
 
 Bacillus of Erysipelas of Swine 194 
 
 Bacillus Murisepticus; Mouse Septicemia 195 
 
 Micrococcus of Mai de Pis 196 
 
 Chapter XXVII — Protozoa 197 
 
 Entamoeba Histolytica; Amoeba Dysenteriae 198 
 
 Life Cycle of Malarial Sporozoa 199 
 
 Three Forrns of Malarial Protozoa 201 
 
 Methods of Examination for Malarial Organisms 203 
 
 Trypanosomata 204 
 
 Trypanosoma Lewisi 205 
 
 Trypanosoma Brucei 206 
 
 Sleeping Sickness; Trypanosoma Ugandense Gambiense 207 
 
 Trypanosoma Evansi 208 
 
 Herpetomonas (Leishman-Donovan Bodies) 208 
 
 Piroplasma Boyis (Piroplasma Bigeminum) 208 
 
 Rabies or Hydrophobia — Negri Bodies 209 
 
 Chapter XXVIII — The Micro-organism of Syphilis and Al- 
 lied Organisms 209 
 
 Spirochaeta Pallida 209 
 
 Wassermann Reaction 211 
 
 Noguchi Modification of Wassermann Reaction 214 
 
 Luetin Reaction 216 
 
 Yaws ; 217 
 
 Spirillum of Relapsing Fever 217 
 
 African Tick Fever 218 
 
l6 CONTENTS 
 
 PAGE 
 
 Chapter XXIX— Filterable Organisms 218 
 
 Filterable or Ultra-microscopic Organisms 218 
 
 Small-pox and Vaccinia 218 
 
 Yellow Fever 219 
 
 Measles . 219 
 
 Typhus Fever 219 
 
 Acute Poliomyelitis 219 
 
 Chapter XXX— Yeasts and Molds 220 
 
 Blastomycetes 220 
 
 Saccharomyces Cerevisiae (Torula Cerevisiae) 220 
 
 Saccharomyces Rosaceus; S. Niger; S. Albicans 221 
 
 , Saccharomyces Mycoderma 221 
 
 Oidium 221 
 
 Oidium Lactis 222 
 
 Oidium Albicans (Soor; Thrush Fungus ) 222 
 
 Pathogenic Yeasts 222 
 
 Blastomycetic Dermatitis or Oidiomycosis 223 
 
 Hyphomycetes (True Molds) 223 
 
 Penicillium Glaucum 223 
 
 Mucor Mucedo 224 
 
 Achorion Schonleinii 224 
 
 Trichophyton Tonsurans (Ring- worm) 225 
 
 Microsporon Furfur ' 226 
 
 Aspergillus Glaucus 226 
 
 Aspergillus Fumigatus 226 
 
 Examination of Yeasts and Molds 226 
 
 Cladothrices and Streptothrices 227 
 
 Crenothrix Kiihniana 227 
 
 Cladothrix Dichotoma 227 
 
 Leptothrix Buccalis 228 
 
 Beggiatoa Alba 228 
 
 Streptothrix or Cladothrix Actinomyces (Ray Fungus) 228 
 
 Streptothrix Madurae 230 
 
 Nocardia (Streptothrix) Farcinica; Bovine Farcin du Boeuf . . . 231 
 
 Plant Diseases Due to Bacteria 23 1 
 
 Chapter XXXI — Examination of Air, Soil, antj Water 232 
 
 Chapter XXXII— Bacteria in Milk and Food 246 
 
 Chapter XXXIII — Bacteriologic Examination of the Organs 
 
 AND Cavities of the Human Body 257 
 
 Chapter XXXIV — Germicides, Antiseptics, and Antisepsis . . . 261 
 
 Tables of Chief Characteristics of Principal Bacteria 268 
 
 Non-pathogenic 268 
 
 Pathogenic 286 
 
 Index 30^ 
 
Essentials of Bacteriology 
 
 INTRODUCTION 
 
 History. — The microscope was invented about the latter 
 part of the sixteenth century, and soon after, by its aid, 
 minute organisms were found in decomposing substances. 
 Kircher, in 1646, suggested that diseases might be due to 
 similar organisms, but the means at his disposal were insuffi- 
 cient to enable him to prove his theories. Anthony van 
 Leeuwenhoek, of Delft, Holland (1680 to 1723), so improved 
 the instrument that he was enabled thereby to discover 
 micro-organisms in vegetable infusion, saliva, fecal matter, 
 and scrapings from the teeth. He distinguished several 
 varieties, showed them to have the power of locomotion, and 
 compared them in size with various grains of definite measure- 
 ment. It was a great service that this "Dutch naturalist" 
 rendered the world; and he can rightly be called the "father 
 of microscopy." 
 
 Various theories were then formulated by physicians to 
 connect the origin of different diseases with bacteria; but no 
 proofs of the connection could be obtained. Andry, in 1701, 
 called bacteria worms. Mliller, of Copenhagen, in 1786, 
 made a classification composed of two main divisions — monas 
 and vibrio; and with the aid of the compound microscope was 
 better able to describe them. Ehrenberg, in 1833, with still 
 better instruments, divided bacteria into four orders: bac- 
 terium, vibrio, spirillum, and spirochaete. It was not until 
 2 17 
 
1 8 ESSENTIALS OF BACTERIOLOGY 
 
 1863 that any positive advance was made in connecting bac- 
 teria with disease. Rayer and Davaine had, in 1850, found 
 a rod-shaped bacterium in the blood of animals suffering 
 from splenic fever (sang de rate), but they attached no special 
 significance to their discovery until Pasteur made public his 
 grand researches in regard to fermentation and the role 
 bacteria played in the economy. Then Davaine resumed his 
 studies, and in 1863 established by experiments the bacterial 
 nature of splenic fever or anthrax. 
 
 But the first complete study of a contagious affection was 
 made by Pasteur in 1869, in the diseases affecting silk- worms, 
 — pebrine and flacherie, — which he showed to be due to 
 micro-organisms . 
 
 Then Koch, in 1875, described more fully the anthrax 
 bacillus, gave a description of its spores and the properties 
 of the same, and was enabled to cultivate the germ on arti- 
 ficial media; and, to complete the chain of evidence, Pasteur 
 and his pupils supplied the last link by reproducing the same 
 disease in animals by artificial inoculation from pure cultures. 
 The study of the bacterial nature of anthrax has been the 
 basis of our knowledge of all contagious maladies, and most 
 advances have been made first with the bacterium of that 
 disease. 
 
 Up to 1875 most medical men believed that bacteria 
 originated in pus and did not associate them with the cause 
 of suppuration. Lister then began the practice of treating 
 wounds and operating antiseptically, having formed the 
 theory that inflammation and suppuration were due to the 
 contamination of wounds by germs from the air, instruments, 
 etc. From 1880 to 1890 the most important organisms were 
 discovered and associated with disease. 
 
 In 1890 the discovery of the blood-serum therapy, the 
 antitoxin of Behring, established a new field of research, and 
 much work was undertaken with a view to curing disease. 
 
 The researches of Ehrlich and the endeavors of Metch- 
 nikoff, Hankin and Ehrlich, to account for the phenomena of 
 immunity, brought forth a great mass of literature and es~ 
 
INTRODUCTION 1 9 
 
 tablished the "lateral-chain" theory and theory of phago- 
 cytosis. These theoretic problems occupied the attention of 
 the workers from 1890 to 1905 and are by no means ended. 
 Laveran, in 1881, had discovered the protozoa of malaria, 
 and in 1903 Button had associated trypanosomes with 
 sleeping sickness. In 1905 Schaudinn, by demonstrating 
 the cause of syphilis to be a protozoon, gave added im- 
 portance to this particular group of micro-organisms, and 
 today investigators are looking in this branch of microbiology 
 for the cause of cancer. 
 
 The serum reactions of Wassermann and Noguchi, the 
 tuberculins and other products of bacterial growth useful in 
 diagnosis and treatment, have interested the whole medical 
 world, and every physician must of necessity be familiar with 
 some part of this knowledge. 
 
 There is hope that the technic and the microscope will 
 receive more attention in the next few years, so that the so- 
 called ultramicroscopic and filterable organisms that are 
 believed to exist will be definitely determined, and also the 
 cause of such epidemic diseases as smallpox and scarlet fever 
 be ascertained. 
 
PART I 
 GENERAL BACTERIOLOGY 
 
 CHAPTER I 
 STRUCTURE AND DEVELOPMENT OF BACTERU 
 
 The bacteria occupy the lowest plane of plant life known 
 to us, though they are by no means as primitive in their 
 biology as was formerly supposed, and it is quite possible 
 that still simpler forms may be discovered. The ultra- 
 microscope gives promise of such minute organisms, and 
 has made visible particles of matter yj--^- the size of our 
 smallest known bacteria. 
 
 The numerous unicellular vegetable organisms which form 
 the lower limit of plant life multiply by fission and are 
 
 *^'l^fe> -^ 
 
 Fig. I. — ^Types of bacteria: a, Micrococcus; b, spirillum; c, bacillus. 
 
 hence called the Schizophyta, or splitting plants. This 
 group is subdivided into two classes — (a) the Schizophycece, 
 or fission algae, and (b) the Schizomycetes^ or fission fungi, 
 
 jor bacteria, as we usually call them. 
 
 TV Bacteria are unicellular masses of protoplasm of microscopic 
 size, multiplying by fission and existing without chlorophyl, 
 
 I Three main types are found: (i) Globular forms, called 
 cocci; (2) straight rod-shaped forms, called bacilli; (3) curved 
 or spiral rods, called spirilla. (See Fig. i.) 
 
22 ESSENTIALS OF BACTERIOLOGY 
 
 Classifications. — Various ones have been proposed: Mor- 
 phologic, as micrococci, spirilla, and bacilli. Physiologic, ac- 
 cording to their activities and functions, as acid bacteria, 
 alkah and indol bacteria; then subdivisions, according to 
 motiHty or need for oxygen, but none are satisfactory. 
 The tendency to place bacteria similar in their disease- 
 producing manifestations in one group is growing, as, for in- 
 stance, the colon group, the pus-producers, the pneumonic 
 group, etc. 
 
 Structure. — Bacteria are cells; they appear as round or 
 cylindric, of an average diameter on transverse section of 
 o.ooi mm. (=1 micromillimeter), written /x = ^5 o0 o inch. 
 The cell, as other plant-cells, is composed of a membranous 
 cell-wall and cell-contents or cytoplasm. 
 
 Cell-wall. — The cell- wall is composed either of hemi- 
 cellulose, or a form of albumin, since it is less permeable than 
 cellulose membrane. The membrane is firm, and can be 
 brought plainly into view by the action of iodin upon the 
 cell-contents, which contract them. 
 
 Cell-contents. — ^The contents of the cell consist mainly of 
 protoplasm, usually homogeneous, but in some varieties 
 finely granular, or holding pigment, chlorophyl, fat-droplets, 
 and sulphur in its structure. The protoplasm permits osmo- 
 sis, and is like that of other plant-cells in its structure. 
 
 Chemic Composition of Bacteria. — The ash is mostly 
 phosphoric acid; potassium, chlorin, and calcium are present 
 to a small extent; 80 to 90 per cent, is water. The bacteria 
 resemble the lower animals, rather than plants, in chemic 
 composition. 
 
 Nuclein, hypoxanthin, and other nitrogen compounds are 
 found in most bacteria. Varies with media in which grown; 
 the. proteids are about 10 per cent.; fats, i per cent.; ash, 
 0.75 per cent. 
 
 Gelatinous Membrane. — ^The outer layer of the cell- 
 membrane can absorb water and become gelatinoid, forming 
 either a little envelop or capsule around the bacterium or 
 preventing the separation of the newly branched germs, 
 
STRUCTURE AND DEVELOPMENT OF BACTERIA 23 
 
 forming chains and bunches, as streptococci and staphylococci. 
 Long filaments are also formed. 
 
 Zooglea. — When this gelatinous membrane is very thick, 
 irregular masses of bacteria will be formed, the whole growth 
 being in one jelly-like lump. This is termed a zooglea {^Coov, 
 animal, yKoios, glue). 
 
 Locomotion. — Many bacteria possess the faculty of self- 
 movement, carrying themselves in all manner of ways across 
 the microscopic field — some very quickly, others leisurely. 
 
 Vibratory Movements. — Some bacteria vibrate in them- 
 selves, appearing to move, but they do not change their 
 
 / 
 
 /5 a 
 
 Fig. 2. — XyP^s of flagelia: a. Vibrio choleras, one flagellum at the end 
 — monotrichla txpe; &, Bacterium syncyaneum, tuft of flagella at the 
 encl^ rarely atlfie side — lophgt richia type ; c, Bacterium vulgare, flagella 
 arranged all about — peritrichia~type (Lehmann and Neumann). 
 
 place; these movements are denoted as molecular or ''Brown- 
 ian," and are due to purely physical causes, such as may be 
 obtained by suspending fine grains of carmin in water. 
 
 Flagella. — Little threads or lashes are found attached to 
 many of the motile bacteria, either at the poles or along the 
 sides — sometimes only one, and on some several, forming a 
 tuft. 
 
 These flagella are in constant motion, and can probably be 
 considered as the organs of locomotion; they have not been 
 discovered upon all the motile bacteria, owing, no doubt, to 
 our imperfect methods of observation. They can be stained 
 and have been photographed. (See Fig. 2.) Flagella serve 
 
24 ESSENTIALS OF BACTERIOLOGY 
 
 sometimes to increase food-supply, and have been found on 
 some species whicJi are non-motile. 
 
 Reproduction. — Bacteria mult iply through simple divi- 
 sion or fission, as it is called. Spore formation is simply a 
 resting stagehand hot a means of multiplication. To accom- 
 plish division the cell elongates, and at one portion, usually 
 the middle, the cell-wall indents itself gradually, forming a 
 septum and dividing the cell into two equal parts, just as 
 occurs in the higher plant and animal cells. (See Fig. 3.) 
 
 Successive divisions take place, the new members either 
 existing as separate cells or forming part of a community or 
 
 Fig. 3. — Division of bacteria: a, Division of a micrococcus; h, division of 
 a bacillus (after Mace). 
 
 group. It has been computed that if division takes place 
 every hour, as it often does, one individual in twenty-four 
 hours will have 7,000,000 descendants. 
 
 Spore Formations. — Two forms of sporulation, endo- 
 sporous and arthrosporous. 
 
 Endosporous. — First, a small granule develops in the pro- 
 toplasm of a bacterium; this increases in size, or several little 
 granules coalesce to form an elongated, highly refractive, 
 and clearly defined object, rapidly attaining its real size, and 
 this is the spore. The remainder of the cell-contents has now 
 disappeared, leaving the spore in a dark, very resistant mem- 
 brane or capsule, and beyond this the weak cell-wall. The 
 
STRUCTURE AND DEVELOPMENT OF BACTERIA 
 
 25 
 
 cell-wall dissolves gradually or stretches and allows the spore 
 to be set free. 
 
 Each bacterium gives rise to but one spore. It may be at 
 either end or in the middle (Fig. 4). Some rods take on a 
 peculiar shape at the site of the spore, making the rod look 
 like a drum-stick or spindle — Clostridium (Fig. 5). 
 
 Spore Contents. — What the real contents of spores are is 
 not known. In the mother-cell at the site of the spore little 
 granules have been found which stain differently from the rest 
 
 Fig. 4. — Sporulation (after De Bary). 
 
 Fig. 5. — Clostridium. 
 
 of the cell, and these are supposed to be the beginnings — the 
 sporogenic bodies. The most important part of the spore is 
 its capsule; to this it owes its resisting properties. It con- 
 sists of two separate layers — a thin membrane aroimd the 
 cell, and a firm outer gelatinous envelop. 
 
 Gennination. — When brought into favorable conditions, 
 the spore begins to lose its shining appearance, the outer firm 
 membrane begins to swell, and it now assumes the shape and 
 size of the cell from which it sprang, the capsule having burst, 
 so as to allow the young bacillus to be set free. 
 
 Requisites for Spore Formation. — It was formerly 
 thought that when the substratum could no longer maintain 
 
26 ESSENTIALS OF BACTERIOLOGY 
 
 it, or had become infiltrated with detrimental products, the 
 bacterium-cell produced spores, or rather turned itself into a 
 spore to escape annihilation; but we believe now that only 
 when conditions are the most favorable to the well-being of 
 the cell does it produce fruit, just as with every other type of 
 plant or animal life, a certain amount of oxygen and heat 
 being necessary for good spore formation. The question is 
 still unsettled, however. 
 
 Asporogenic Bacteria. — Bacteria can be so damaged that 
 they will remain sterile — not produce any spores. This con- 
 dition can be temporary only or permanent. 
 
 Arthrosporous. — In the other group, called arthrospores, 
 individual members of a colony or aggregation leave the same, 
 and become the originators of new colonies, thus assuming the 
 character of spores. 
 'The micrococci furnish examples of this form. 
 
 Some authorities have denied the existence of the arthro- 
 sporous formation. 
 
 Resistance of Spores. — Because of the very tenacious en- 
 velop, the spore is not easily influenced by external measures. 
 It is said to be the most resisting object of the organic world. 
 
 Chemic and physical agents that easily destroy other life 
 have very little effect upon it. 
 
 Many spores require a temperature of 140° C. dry heat for 
 several hours to destroy them. The spores of a variety of 
 potato bacillus (Bacillus mesentericus) can withstand the 
 application of steam at ioo° C. for four hours. 
 
 CHAPTER II 
 
 BIOLOGIC AND CHEMIC ACTIVITIES 
 
 Origin of Bacteria. — As Pasteur has shown, all bacteria 
 develop from preexisting bacteria or the spores of the same. 
 They cannot arise out of nothing. 
 
 Distribution. — The wide and almost universal diffusion 
 of bacteria is due to the minuteness of the cells and the 
 
BIOLOGIC AND CHEMIC ACTIVITIES 27 
 
 few requirements for their existence. In a drop of water 
 1,700,000,000 cocci can find space. 
 
 Very few places are free from germs; the air on the high seas 
 and on the mountain-tops is said to be free from bacteria, 
 but this is questionable. 
 
 Specific Nature. — One kind of bacterium will not pro- 
 duce another kind. A bacillus does not arise from a micro- 
 coccus, or the typhoid fever bacillus produce the bacillus of 
 tetanus. 
 
 Saprophytes and Parasites. — Saprophytes: caTrpos, put- 
 rid; (f)VT6v, plant. Parasites: irapa, aside of; alros, food. 
 Those bacteria which live on the dead remains of organic life 
 are known as saprophytic bacteria, and those which choose the 
 living bodies of their fellow-creatures for their habitat are 
 called parasitic bacteria. Some, however, develop equally 
 well as saprophytes and parasites. They are called faculta- 
 tive parasites. All pathogenic (disease-producing) bacteria 
 are parasites. 
 
 Conditions of Life and Growth of Bacteria. — Influence 
 of Temperature. — In general, a temperature ranging from io° 
 C. to 40° C. is necessary to the life and growth of bacteria. 
 
 Saprophytes take the lower temperatures; parasites, the 
 temperature more nearly approaching the animal heat of the 
 warm blooded. Some forms require a nearly constant heat, 
 growing within very small limits, as the bacillus of tubercu- 
 losis. 
 
 Some forms can be arrested in their development by a 
 warmer or colder temperature, and then restored to activity 
 by a return to the natural heat. 
 
 A few varieties exist only at freezing-point of water, and 
 others again will not live under a temperature of 60° C. and 
 thrive in hot springs at a temperature of 89° C. 
 
 For the majority of bacteria a temperature of 60° C. will 
 prevent development, but steam under pressure at 125° C. is 
 necessary to destroy spores. Ice may contain active bac- 
 teria; frozen milk permits the growth of bacteria. 
 
 Influence of Oxygen. — Two varieties of bacteria in relation 
 
28 ESSENTIALS OF BACTERIOLOGY 
 
 to oxygen — the one aerobic, growing in air; the other, anae- 
 robic, Hving without air. 
 
 Obligate aerobes, those which exist only when free or 
 atmospheric oxygen is present. 
 
 Facultative aerobes, those that live best when atmos- 
 pheric oxygen is present, but can live without it. 
 
 Obligate or true anaerobes, those w^hich cannot exist in 
 the presence of free oxygen; facultative anaerobes, those 
 which exist better where there is no free oxygen, but 
 can live in its presence. 
 
 Some derive the oxygen which they require out of their 
 nutriment, so that a bacterium may be aerobic and yet not 
 require the presence of free oxygen. 
 
 Aerobes may consume the free oxygen of a region and thus 
 allow the anaerobes to develop. By improved methods of 
 culture many varieties of anaerobes have been discovered. 
 
 Influence of Light. — Sunlight is very destructive to bacteria. 
 A few hours' exposure to the sun has been fatal to anthrax 
 bacilli and the cultures of Bacillus tuberculosis. The sun's 
 rays, however, must come in direct contact with the germs, 
 and are usually active only on the surface cultures. The 
 rays at the violet end of the spectrum are the most active. 
 The electric arc-light has much the same effect as sunlight on 
 bacteria; the effect of sunlight is not due to heat-rays. 
 
 Effects of Electricity. — Electricity arrests growth. 
 
 Effects of Rontgen Rays. — Have little or no effect on arti- 
 ficial cultures, but in the living tissues a pronounced bacteri- 
 cidal effect is produced, perhaps through the stimulation of 
 the body-cells. 
 
 Moisture. — Water is necessary for the development of most 
 bacteria; complete drying is usually destructive after a few 
 days. 
 
 Heat. — Dry heat is much less destructive than moist heat, 
 steam under pressure most destructive. 
 
 Biologic Activities. — Bacteria feeding upon organic com- 
 pounds produce chemic changes in them, not only by the 
 withdrawal of certain elements, but also by the excretion 
 of these elements changed by digestion. Sometimes such 
 
BIOLOGIC AND CHEMIC ACTIVITIES 29 
 
 changes are destructive to the bacteria themselves, as when 
 lactic and butyric acids are formed in the media. 
 
 Oxidation and reduction are carried on by some bacteria. 
 Ammonia, hydrogen sulphid, and trimethylamin are a few of 
 the chemic products produced by bacteria. Nitrites in the 
 soil are reduced to ammonia. 
 
 Nitrification. — Albuminoids changed into indol, skatol, 
 leucin, etc.; then these into ammonia, am.monia into nitrites, 
 nitrites into nitrates. 
 
 Ptomains. — Brieger found a number of complex alkaloids 
 closely resembling those found in ordinary plants, and which 
 he named ptomains, from Trrwjua, corpse, because obtained 
 from putrefying objects. These were at one time held to be 
 the chief causes of bacterial disease, but are no longer con- 
 sidered of much importance. 
 
 Chemic Products. — Secretions, as, for instance, enzymes, 
 toxins. Excretions, pigments, indol, cell proteins, bacterins. 
 
 Proteins. — The protein contents of the bacterial cell may 
 cause inflammation and fever. 
 
 Producers of Disease. — Various pathologic processes 
 are caused by bacteria, the name given to such diseases being 
 infectious diseases, and the germs themselves called disease- 
 producing or pathogenic bacteria. Those which do not form 
 any pathologic process are called non- pathogenic bacteria. 
 
 Fermentation. — This is an important property of bac- 
 terial activity. 
 
 Enzymes. — An enzyme or ferment is a substance capable 
 of inaugurating a chemic reaction without entering into the 
 reaction, and is a product of living cells. 
 
 Bacterial enzymes are closely related to the ferments of 
 special cells of higher animals and plants, like ptyalin and 
 diastase. 
 
 Ferments may be diastatic, changing starch into sugar, or 
 proteolytic, transforming albumins into more soluble sub- 
 stances, of which gelatin liquefaction is an example. Invert- 
 ing, changing a sugar from one that does not undergo fermen- 
 tation into one that does. 
 
30 ESSENTIALS OF BACTERIOLOGY 
 
 Coagulating, fat-splitting, hydrolytic ferments are some of 
 the other varieties. 
 
 Toxins and toxalbvimins are various albuminoids pro- 
 duced in the animal organism and in culture-media which are 
 very poisonous, and are considered the prime cause of disease. 
 
 Putrefaction. — When fermentation is accompanied by 
 development of offensive gases, a decomposition occurs which 
 is called putrefaction, and this, in organic substances, is due 
 entirely to bacteria. 
 
 Pigmentation. — Some bacteria are endowed with the 
 property of forming pigments either in themselves, or pro- 
 ducing a chromogenic body which, when set free, gives rise to 
 the pigment. In some cases the pigments have been isolated 
 and many of the properties of the anilin dyes discovered in 
 them. 
 
 Phosphorescence. — Many bacteria have the power to 
 form light, giving to various objects which they inhabit a 
 characteristic glow or phosphorescence. 
 
 Fluorescence. — An iridescence, or play of colors, devel- 
 ops in some of the bacterial cultures. 
 
 Gas-formation. — Many bacteria, anaerobic ones especi- 
 ally, produce gases, noxious and odorless; in the culture- 
 media the bubbles which arise soon displace the media. 
 
 Odors. — Some germs form odors characteristic of them: 
 some are pleasant and even fragrant; others, foul and nause- 
 ous. 
 
 Effect of Age. — With age, bacteria lose their strength and 
 die. 
 
 CHAPTER III 
 INFECTION 
 
 How Bacteria Cause Disease. — Many theories have 
 been advanced to explain the action of bacteria in causing 
 disease, but only a few of the more important ones can be 
 discussed. Nearly all the changes found in the organs of the 
 
INFECTION 
 
 31 
 
 body are similar to those produced by drugs and can be 
 reproduced by the injection of bacterial poisons. 
 
 Infection is the successful invasion of an organism by 
 microparasites, and implies an abnormal state resulting from 
 the deleterious action of the parasite upon the host. 
 
 Sources of infection may be exogenous or endogenous. 
 Exogenous infections result from the successful invasion of 
 the body by microparasites from sources entirely apart from 
 the individual infected. Infection by the typhoid bacillus 
 from water or milk, by the Spirochaeta pallidum from dental 
 instruments or drinking-cups, contraction of smallpox from 
 fomites, and contraction of malaria from the bites of mosqui- 
 tos are examples of exogenous infection. 
 
 Endogenous infections result from the successful invasion 
 of the body by microorganisms normally present on the 
 body. The skin and mucous membranes furnish lodgment 
 for a great variety of virulent pathogenic organisms which, 
 when the resistance of the body is lowered, immediately 
 become invasive. The pneumococcus is a normal inhabitant 
 of the mouth and pharynx, but causes no infection until the 
 body resistance is lowered. When this occurs, tonsillitis, 
 pharyngitis, or lobar pneumonia may follow. 
 
 Pathogenesis. — The ability of a microorganism to do 
 harm depends on its invasive powers and its ability to gener- 
 ate toxins or both. 
 
 Toxins. — Little is known of the chemic nature of toxins. 
 Undoubtedly some are related to albumins. Others give no 
 reactions common to compounds of this group. 
 
 (A) Intracellular or Insoluble Toxins. — These are chiefly 
 within the bodies of the bacteria, and are set free by disin- 
 tegration of the organism. This group comprises most of 
 the pathogenic bacteria. 
 
 (B) Extracellular or Soluble Toxins. — These toxins are ap- 
 parently excreted by the bacteria, and are foimd in the 
 surrounding medium. This group includes the diphtheria 
 and tetanus bacilli. 
 
 It has been shown that bacteria which apparently do not 
 
32 ESSENTIALS OF BACTERIOLOGY 
 
 produce toxins in artificial media may do so in the human 
 body. These toxic substances are formed by the bacteria to 
 combat the body defenses, and have been called by Bail 
 aggressins. They have a paralytic action on phagocytes. 
 A sublethal dose of bacteria, if injected along with aggressin, 
 will cause death. 
 
 Toxins are not stable, though tetanus toxin has been kept 
 in powdered form for a number of years. They are soluble 
 in water, destroyed by heat (thermolabile), and precipitated 
 by ammonium sulphate. 
 
 The Cardinal Conditions for Infection. — (i) The 
 microorganism must be sufficiently virulent; (2) it must enter 
 in sufficient numbers and by appropriate channels; and (3} the 
 host must be susceptible. 
 
 Virulence is a very variable quality, and depends on the 
 ability of the micro-organism to invade or produce toxin or 
 both. The virulence may be decreased by repeated trans- 
 planting on artificial culture-media or by. the action of heat. 
 It may be increased by adding animal juices to the culture- 
 medium, by inclosing the micro-organism in a collodion sac, 
 and placing the sac in the abdominal cavity of an animal, and 
 by repeatedly passing it through animals. 
 
 Infection Depends on Quantity of Bacteria. — Unless 
 a sufficient number of bacteria enter the tissues no infection 
 follows, because the body defenses immediately destroy the 
 bacteria. The number necessary to cause infection depends 
 on their virulence and the susceptibility of the host. Strep- 
 tococci may become so virulent that a single coccus will cause 
 death in a rabbit. It has been found that 820 tubercle bacilli 
 are necessary to kill a guinea-pig, and 1,000,000 staphylo- 
 cocci to kill a rabbit. The period of incubation can be ex- 
 plained on the supposition that the organism requires a 
 definite time to generate the amount of toxin necessary to 
 produce symptoms. 
 
 Avenues of Infection.— The organism must gain en- 
 trance into the tissue or find lodgment on some part of the body 
 that has been injured. Even when several avenues of infec- 
 
INFECTION 33 
 
 tion are open, the parasite most commonly invades through 
 one that may, therefore, be regarded as the most appropriate 
 for entrance; this channel furnishes the typical picture of 
 the infection. 
 
 Susceptibility of the Host. — Susceptibility varies in 
 different species of animals, in different members of the same 
 species, in the same individual at different times, and in the 
 same individual to different organisms. 
 
 Susceptibility may he natural, as in smallpox; acquired, as 
 from exposure to conditions which lower the vitality, such 
 as hunger, cold, intoxication, fatigue, inhalation of noxious 
 vapors, and traumatic shock. Inherited susceptibility also 
 occurs. The transmission of certain inherited character- 
 istics, as narrow chest, predisposes to infection of the lungs. 
 
 Mixed infections are the result of two or more micro- 
 organisms successfully invading and intoxicating the host 
 at the same time. 
 
 Local Effects of Bacteria. — By mechanical obstruction 
 from rapid growth of the bacteria, thrombosis, w4th its con- 
 sequences, may occur. Destruction of a part of the cells of a 
 tissue with necrosis can arise from irritation, the bacteria 
 acting as a foreign body. 
 
 General Effects. — Bacteremia or septicemia occurs when 
 bacteria proliferate and enter the whole system, as when 
 anthrax and typhoid cause general disease. 
 
 Toxemia. — When the poisons become widely distributed, 
 though the bacteria remain few and localized, and never or 
 seldom enter the circulation, as diphtheria and tetanus. 
 
 Pyemia, a form of bacteremia, in which secondary or 
 metastatic foci of suppuration occur throughout the body. 
 
 Suppurative bacteria are those which give rise to inflam- 
 mation and suppuration locally at the point of entrance, and 
 secondarily through metastasis. Any organism may cause 
 suppuration, but certain ones are peculiarly inclined to give 
 rise to pus, and are known as pyogenic organisms. 
 
 Specific Bacteria. — Infective bacteria are, as a rule, 
 specific, the particular toxin having a specific action and caus- 
 3 
 
34 ESSENTIALS OF BACTERIOLOGY 
 
 ing a disease peculiar to the micro-organism. Thus typhoid 
 fever is a disease distinctly different from tuberculosis; the 
 infective organisms are distinct and the poisons they produce 
 have specific characteristics. 
 
 The Nature of Toxins. — Very similar to the venom of 
 serpents; highly poisonous in minute doses (tto o" gram of 
 tetanus toxin will kill a horse weighing 600 kilos — 1200 
 pounds). At first toxins were called ptomains, or cadaveric 
 alkaloids; but this term is applied now to such poisons as 
 have a basic nature and arise in decomposing meat, cheese, 
 and cream as a result of chemical change in the material, the 
 bacteria causing the change. Then they were called toxal- 
 bumins, and were supposed to belong to an albumin series; 
 but when the bacteria are grown in non-albuminous media, 
 the toxins correspond more in their chemical composition to 
 a ferment, and therefore it is supposed that the albumin part 
 of the toxin is furnished by the blood or albuminous media in 
 which it is formed. The term toxin is to be preferred in 
 speaking of bacterial poisons. 
 
 CHAPTER IV 
 IMMUNITY 
 
 Ordinary Defenses to Bacterial Invasion. — The un- 
 broken skin and the connective tissue underneath prevent 
 the passage of bacteria. The unbroken mucous surface of 
 eye, nose, and mouth, because of the continuous washing, 
 prevents the numerous bacteria that are constantly present 
 in the discharge from finding suitable lodgment. The hairs 
 and ciliated epithelium in upper respiratory tract retain 
 many a dust particle and pathogenic cell on its way to the 
 lungs. The acid gastric juice is destructive to most bacteria, 
 and protects not only the stomach, but the intestines as well. 
 
IMMUNITY 35 
 
 The intestinal secretions are but mildly preventive of bac- 
 terial growth, but peristalsis aids in dislodgment of micro- 
 organisms. 
 
 Immunity is the ability to resist infection and intoxica- 
 tion. It is always relative and never absolute. 
 
 f Natural 
 Immunity 
 
 Acquired 
 
 Active. 
 Passive. 
 
 Natural immunity is a natural inherited resistance against 
 infection or intoxication, peculiar to certain groups of animals, 
 but common to all the mdividuals of these groups. It is 
 peculiar to the kind of animal, not to the individual. Thus 
 the field mouse is susceptible to glanders; the house mouse is 
 slightly immune, and the white mouse is immune. 
 
 Acquired immunity is resistance to infection or intoxica- 
 tion possessed by certain animals of a naturally susceptible 
 kind, in consequence of circumstances peculiar to them as 
 individuals. Active acquired immunity arises from the activ- 
 ities performed by the organism itself. It depends on infec- 
 tion or intoxication, which may have been accidental or 
 intentional; i. e., for the purpose of producing immunity. 
 Some accidental infections, recovery from which renders the 
 individual immune, are measles, scarlet fever, and smallpox. 
 Other infections are followed by an immunity of short dura- 
 tion, as typhoid fever and pneumonia. 
 
 Immunity from intentional infection or intoxication is pro- 
 duced by — {A) bringing about a different disease, as in the 
 production of vaccinia to bring about immunity to small- 
 pox. (B) Inoculation with killed bacteria, as in the protec- 
 tive inoculation against typhoid fever or bubonic plague. 
 (C) Inoculation with bacterial products, as diphtheria or tetanus ■ 
 toxin. (D) Inoculation with attenuated cultures of micro- 
 organisms, as in Pasteur's anthrax vaccine or Haffkine's 
 cholera vaccine. (E) Inoculation with virus of increasing viru- 
 lence, as in the protective inoculations against hydrophobia. 
 
36 ESSENTIALS OF BACTERIOLOGY 
 
 (F) Inoculation with sublethal doses of virulent bacteridy 
 beginning with small doses, and gradually increasing their 
 size. Guinea-pigs inoculated in this way have acquired a 
 marked degree of immunity to tuberculosis. 
 
 Passive acquired immunity is always artificially sup- 
 plied to the animal. It follows when antibodies are supplied 
 from an immunized animal to one normally susceptible. 
 Immunization against diphtheria by the injection of diph- 
 theria antitoxin is a good example. 
 
 Theories of Immunity. — Phagocytic Theory of Metchni- 
 kojf. — Immunity is dependent on the action of the phago- 
 cytes and their ferments. The phagocytes are of two kinds 
 — macrophages, which include endothelia and connective-tis- 
 sue cells, and micro phages, the polymorphonuclear leukocytes. 
 These phagocytes liberate ferments — macrocytase and micro- 
 cytase respectively. Infecting organisms and their toxins 
 are destroyed by the phagocytes and their ferments. This 
 theory has been replaced by the lateral or side-chain theory of 
 Ehrlich. 
 
 Ehrlich^s Lateral Chain Theory. — This derives its name 
 from th e fact that it presents an analogy to what happens 
 in the benzol ring of organic chemistry when its replaceable 
 atoms of hydrogen are substituted by "side chains" of more 
 or less complex nature. The molecule of protoplasm is sup- 
 posed to consist of a central atom group, provided with a 
 large number of side chains which subserve the vital processes 
 of the molecule by combining with other organic molecules. 
 These side chains are called receptors, and are of many dif- 
 ferent kinds, so as to fit them for combination with many 
 different varieties of extraneous groups. 
 
 Three orders of receptors are described: Receptors of the first 
 order, which concern themselves with the assimilation of 
 simple substances (toxins, ferments, and other cell secre- 
 tions), utilizing a single haptophore. Antitoxins, as an 
 example. 
 
 Receptors of the second order, which, in addition to the 
 haptophore group, possess a second group, which affects the 
 
IMMUNITY 37 
 
 coagulation. Toxins may be regarded as receptors of the 
 second order thrust off by the bacteria. 
 
 Receptors of the third order, which possess two haptophore 
 groups, one of which effects the union with the food-stuffs, 
 whereas the other lays hold on certain substances circulating 
 in the blood plasma, the complements, which cause ferment- 
 like actions — cytolysins, as an example. 
 
 The Formation of Antitoxin According to the Lateral Chain 
 Theory. — The toxin molecule consists of two groups: (A) 
 
 m 
 
 Fig. 6. — Graphic representation of receptors of the first order and of 
 toxin uniting with the cell-receptor: a, Cell-receptor; b, toxin molecule; 
 c, haptophore of toxin molecule; d, toxophore of to:dn molecule; e, hapto- 
 phore of the cell-receptor (Ehrlich). 
 
 The haptophore or combining group, by which the toxin 
 molecule can join the receptor of the cell, and (B) the toxo- 
 phore, or poisoning group, by which means it can attack the 
 cell protoplasm after having been fixed to it by the hapto- 
 phore group. 
 
 The effect of the toxin depends on the number of mole- 
 cules attached to the cell. A great number would bring 
 
38 ESSENTIALS OF BACTERIOLOGY 
 
 about death of the cell, while a few would act as an irri- 
 tant. 
 
 Weigerfs Law. — When a cell is attacked by a few mole- 
 cules of toxin, it reacts by forming new side chains or recep- 
 tors, and, in accordance with the law of Weigert, always in 
 excess. Repeated injections of toxins in increasing doses 
 cause such an overproduction of receptors of the first order 
 that they are thrust from the cell and float free in the blood- 
 
 Fig. 7. — Graphic representation of receptors of the second order and 
 of some substances uniting with one of them: c, Cell-receptor of the 
 second order; d, toxophore or zymophorous group of the receptor; e, 
 haptophore of the receptor; /, food substance or product of bacterial 
 disintegration uniting with the haptophore of the cell-receptor (Ehrhch). 
 
 stream. Here they can combine with toxin molecules, just 
 as when they are attached to the cell. By thus combining, 
 they prevent the toxin from reaching the cells. 
 
 Antitoxins are specific in their action; that is, each anti- 
 toxin will neutralize only a certain toxin. Thus diphtheria 
 antitoxin will not neutralize tetanus toxin or snake venom, 
 
IMMUNITY 39 
 
 nor will tetanus antitoxin neutralize diphtheria toxin or 
 snake venom. 
 
 Lock and Key Theory. — This specific action is explained by 
 supposing the molecule of toxin to have a shape peculiar to 
 itself. The molecule of diphtheria toxin is of such shape 
 that the haptophore end will fit only on certain receptors 
 of a cell; the molecule of tetanus toxin will fit on only certain 
 other receptors. 
 
 Fig. 8. — Graphic representation of receptors of the third order, and 
 of some substance uniting with one of them: c, Cell-receptor of the third 
 order, amboceptor; e, one of the haptophores of the amboceptor with 
 which some food substance or product of bacterial disintegration, /, may- 
 unite; g, the other haptophore of the amboceptor with which complement 
 may unite; k, complement; h, the haptophore, and z, the zymotoxic 
 group of the complement (Ehrlich). 
 
 An antitoxic serum is a suspension of receptors of the first 
 order in blood-serum. Antitoxins for diphtheria and tetanus 
 are the most common. 
 
 Precipitins are bodies in serum which, when added to a 
 protein in solution, will cause a precipitate to form. The 
 precipitins are specific and act only with similar proteins. 
 
 When a protein or food substance is injected into an 
 
40 ESSENTIALS OF BACTERIOLOGY 
 
 animal and becomes attached to the cell receptors of the 
 second order by means of its haptophore group, the cell is 
 irritated and new receptors are formed. Further injection 
 of larger amounts of protein stimulate the cell to such an 
 excessive formation of these receptors that they are thrust 
 free into the blood-stream. 
 
 A precipitin serum is a suspension of receptors of the second 
 order in blood-serum. 
 
 The phenomenon of precipitation has found forensic 
 application in the identification of blood-stains. 
 
 Agglutinins are bodies present in a serum which, when 
 added to bacterial cells, cause them to clump, and, if motile, 
 to lose their motility. They are specific when diluted, and 
 of value in diagnosis in such diseases as typhoid and Malta 
 fever. 
 
 Agglutinins are formed in response to the stimulus given the 
 cells of a body by the union of antigenic cell-receptors with 
 receptors of the second order of the cells of the animal re- 
 ceiving the injection. Repeated injections stimulate the 
 cells to the formation of such excessive quantities of these 
 receptors that they are thrown from the cells into the blood- 
 stream. 
 
 Agglutinins bear no relation to the degree of immunity, 
 and should never be used as an index to immunity. 
 
 Cytolysins are bodies present in a serum which will dis- 
 solve or destroy cells (corpuscles, bacteria, etc.). 
 
 They are formed in the same manner as the agglutinins, 
 except that receptors of the third order are involved. Recep- 
 tors of the third order have a double combining affinity. 
 One part attaches itself to the receptor of the cell injected, 
 and the other combines with complement. 
 
 Complement {alexin or cytase) is a thermolabile, ferment- 
 like body found in all normal sera. 
 
 Amboceptors y ^^ substance sensibilatrice,'' fixateur, copula ^ 
 and desmon are names given to receptors of the third order. 
 
 Cytolytic sera are of little use in medicine. Sera have been 
 prepared against staphylococci, pneumococci, streptococci, 
 
IMMUNITY 41 
 
 and others. Wassermann has made a very efficacious anti- 
 meningococcus serum. 
 
 Opsonins. — Opsonins are substances in the blood-serum 
 which act on bacteria and prepare them for phagocytosis. 
 Opsonins can be increased by whatever increases immunity. 
 An increase is coincident with increased immunity. The 
 most common method of bringing about an increase is by the 
 injection of killed cultures of bacteria. 
 
 Opsonins normally present in the serum are not specific. 
 Opsonins resulting from reaction to infection or inoculation 
 are specific. 
 
 The opsonic index is the ratio between the number of 
 bacteria ingested by living leukocytes when operating in the 
 serum of a test and in normal serum respectively. 
 
 After the injection of bacteria the opsonic index falls for 
 a short time. This period is called the negative phase, and 
 is followed by a rise in the index — the positive phase. 
 
 The "estimation of the opsonic index is a very complicated 
 way of finding out very little," and has been abandoned by 
 the great majority of workers. 
 
 Antigens. — Any substance that has, when injected into 
 the body, power to produce an antitoxin or antibacterial 
 body is called an antigen. 
 
 The toxin of diphtheria, if injected, stimulates the normal 
 cells to produce chemic substances (free receptors) which 
 are at liberty to attach themselves to the active toxin mole- 
 cules and thus save the body cells from being acted upon; 
 toxin is, therefore, an antigen. 
 
 Substances which have the power of destroying bacteria 
 are called bactericides; those which dissolve them merely are 
 called hacteriolysins. 
 
 Hemolysis. — ^When the hemoglobin of the red blood-cells 
 is liberated, hemolysis is said to occur. This is brought about 
 by the injection of certain substances, or hemolysins; these 
 are present normally in some sera, and can be developed in 
 others. Lysins and bactericidal substances seem to have 
 two parts — one destroyed by heat (thermolabile), called 
 
42 ESSENTIALS OF BACTERIOLOGY 
 
 complement (the completor), and one, more resistant, called 
 the amboceptor, or combinor, which unites with complement 
 and with the cell. For lysis, therefore, it is necessary that 
 ambocepter be united to the bacteria or cell, and that com- 
 plement be present or added to join with amboceptor, com- 
 pleting the circuit. Complement may be prevented from com- 
 bining with amboceptor by ^^ deviation of the complement.^'' 
 The amboceptor may be in excess, and the free group absorb 
 or attach itself to all the available complement, leaving none 
 to join the amboceptor; or anti-complements may be present 
 to monopohze all this complement and leave none free to unite 
 with amboceptor. This deviation prevents lysis. 
 
 Fixation of Complement. — By adding a definite standardized 
 complement to a mixture of antigen and amboceptor of a 
 similar kind the complement is bound or fixed, and none is 
 left free. If the amboceptor is not like the antigen, the com- 
 plement will not unite the two, will not be bound, and is free 
 to unite with any other amboceptor that may be introduced. 
 If this be a hemolytic amboceptor, and red corpuscles are 
 added as an indicator, the cells will lose their hemoglobin, 
 because hemolysis will occur from the completing of the re- 
 action. The complement will unite to hemolytic ambocep- 
 tor, since it is not fixed or bound by the other amboceptor, 
 and the other amboceptor is not of the same nature as the 
 antigen. This is the principle of the Wassermann serum re- 
 action or test. 
 
 Anaphylaxis or Allergy. — Under certam circumsta,nces 
 the second injection of a proteid as antigen instead of render- 
 ing immune, produces hyper sensitiveness. Behring, in 1892, 
 noticed this with injections of antitoxin, and called it ^'hyper- 
 susceptibility.'^ 
 
 Richet, in 1904, called a similar condition anaphylaxis, or 
 the reverse of prophylaxis, and von Pirquet introduced the 
 term ''allergy,'" "altered reactivity,'''' to express the same thing. 
 Guinea-pigs may be rendered so sensitive by o.ooi c.c. of 
 horse-serum that a second dose within a week or a few days 
 produces fatal shock. 
 
METHODS OF STUDYING BACTERIA 43 
 
 Other proteins, like beef-serum, egg-albumin, red blood- 
 corpuscles, have produced similar results, varying doses and 
 periods of incubation. Human beings may be sensitized by 
 single injections of horse-serum. 
 
 Hay-fever, asthma, puerperal convulsions, and sympathetic 
 ophthalmia partake of the nature of anaphylactic reactions, 
 and the peculiar intolerances to certain articles of food may 
 be better explained by the same theory. 
 
 The sudden attacks of collapse and death which have 
 followed the injection of even small doses of antitoxins made 
 from horse-serum are believed to come from this condition 
 of hypersensitiveness. 
 
 The use of globulins instead of the entire serum has lessened 
 the danger from anaphylaxis. 
 
 CHAPTER V 
 METHODS OF STUDYING BACTERIA*— MICROSCOPE 
 
 Microscope. — Most clinical instruments now on the mar- 
 ket have all the necessary appliances for bacterial examina- 
 tion. Three objectives are advisable — 16 mm. (^ inch); 
 4 mm. 06 inch); 2 mm. (tV inch). It is not so much 
 required to have a picture very large, as to have it sharp and 
 clear. 
 
 Oil-immersion Lens. — ^The penetration and clearness of 
 a lens are very much influenced by the absorption of the rays 
 of Hght emerging from the picture. In the ordinary dry 
 system many of the light rays, being bent outward by the air 
 which is between the object and the lens, do not enter the lens, 
 and are lost. By interposing an agent which has the same 
 refractive index as glass, cedar-oil or clove-oil, for example, 
 all the rays of light from the object enter directly into the lens. 
 
 The "homogeneous system," or oil-immersion lens, con- 
 
44 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 sists of a system of lenses which can be dipped into a drop of 
 cedar-oil placed upon the cover-glass, and which is then ready 
 for use. 
 
 Abbe's Condenser. — The second necessary adjunct is a 
 combination of lenses placed underneath the stage, for 
 bringing wide rays of light directly under the object. It 
 serves to intensify the colored pic- 
 tures by absorbing or hiding the 
 unstained structure. 
 
 This is very useful in searching 
 a specimen for bacteria, since it 
 clears the field of everything that 
 is not stained. It is called Abbe's 
 condenser (Fig. 9). Together with it is usually found an in- 
 strument for shutting off part of the light — a blender or dia- 
 phragm (Fig. 10). When the bacteria have been found, and 
 their relation to the structure is to be studied, the "Abbe" is 
 generally shut out by the iris blender, , and the structure 
 comes more plainly into view. A white light (daylight or a 
 
 Fig. 9. — Abbe's condenser. 
 
 Iris blender. 
 
 Welsbach burner) is best for bacterial study: use the plane 
 mirror with the condenser. 
 
 For all stained bacteria the oil-immersion lens and Abbe con- 
 denser, without the use of blender. For unstained specimens^ 
 oil-immersion and the narrowed blender. 
 
 When examining with low-power objective, use a strong 
 
METHODS OF STUDYING BACTERIA 45 
 
 ocular. When using high-power objective use weak ocular. 
 A revolving nose-piece will be found very useful, since it is 
 sometimes necessary to change the objective on the same 
 field, and this insures a great steadiness of the object. 
 
 Great cleanliness is needed in all bacteriologic methods, 
 but nowhere more so than in the microscopic examination. 
 
 The cover-glass should be very carefully washed in alcohol, 
 and dried with a soft linen rag. To remove the stains on the 
 cover-glasses that have been used they should be soaked in 
 hydrochloric acid or placed in a 6 per cent, aqueous solution 
 of potassium dichromate with 6 per cent, of strong sulphuric 
 acid, washed in water, and kept in absolute alcohol. 
 
 Examination of Unstained Bacteria. — As the coloring of 
 bacteria kills them and changes their shape to soine extent, it 
 
 
 
 Fig, II. — Platinum needles for transferring bacteria, made from No. 27 
 platinum wire inserted in glass rods: a, Looped needle; b, straight- 
 pointed needle (McFarland) . 
 
 is preferable to examine bacteria, when possible, in their 
 natural state. 
 
 We obtain the bacteria for examination either from liquid 
 or solid media. 
 
 From Liquids. — With a long platinum needle the end of 
 which is bent into a loop (Fig. 11, a) obtain a small drop from 
 the liquid containing the bacteria, and place it on a cover- 
 glass or slide, careful that no bubbles remain. 
 
 Sterilize Instruments. — Right here w^e might say that 
 it is best to accustom one's self to pass all instruments, 
 needles, etc., through the flame before and after each proce- 
 dure; it insures safety; and once in the habit, it will be done 
 automatically. 
 
 From Solid Media. — With a straight-pointed platinum 
 needle (Fig. 11, Z>) a small speck of the medium is taken and 
 
46 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 rubbed upon a glass slide with a drop of sterilized water or 
 bouillon, and from this a little is taken on cover-glass, as 
 before. 
 
 The cover-glass with its drop is now placed on the glass 
 slide, carefully pressing out all bubbles. Then a drop of 
 cedar-oil is laid on top of the cover-glass, and the oil-immer- 
 sion lens dipped gently down into it as close as possible to the 
 cover-glass, the narrow blender shutting of the Abbe conden- 
 ser, for this being an unstained specimen, we want but little 
 light. We now apply the eye, and if not in focus, use the 
 fine adjustment or the coarse, but always away from the 
 object — i. e., toward us — since the distance between the speci- 
 
 
 
 
 
 
 
 
 Fig. 12. — A "concave slide" with "hanging drop" (McFarland). 
 
 men and the lens is very slight, it does not require much 
 turning to break the cover-glass and ruin the specimen. 
 Having found the bacterium, we see whether it is bacillus, 
 micrococcus, or spirillum, discover if it is motile or not. 
 The phenomenon of agglutination is observed in this way. 
 
 Hanging Drop (Fig. 12). — When the looped platinum 
 needle is dipped into a liquid, a very finely formed globule will 
 hang to it; this can be brought into a little cupped glass slide 
 (an ordinary microscopic glass slide with a circular depression 
 in the center) in the following manner: The drop is first 
 brought upon a cover-glass; the edges of the concavity on the 
 glass slide are smeared with vaselin, and the slide inverted 
 over the drop; the cover-glass sticks to the smeared slide, 
 
METHODS OF STUDYING BACTERIA 47 
 
 which, when turned over, holds the drop in the depression 
 covered by the cover-glass, thus forming an air-tight cell; 
 here the drop cannot evaporate. Both slide and cover-glass 
 should first be sterilized by heat. 
 
 Search for the bacteria with a weak lens; having found 
 them, place a drop of cedar-oil upon the cover-glass, and 
 bring the oil immersion into place (here is where a nose-piece 
 comes in very useful), careful not to press against the cell, 
 for the cover-glasses are very fragile in this position. 
 
 Search the edges of the drop rather than the middle; the 
 bacteria will usually be very thick in the center and not so 
 easily distinguished. 
 
 Spores, automatic movements, fission, and cultivation in 
 general can be studied for several days. This moist chamber 
 can be placed in a brood-oven or on the ordinary warming 
 stage attachment of the microscope. 
 
 Hanging Block. — A small slice of agar containing some 
 of the growth seared to the glass slide with a hot needle. 
 
 Agglutination as observed in Widal's test is best seen in the 
 hanging drop. 
 
 CHAPTER VI 
 
 METHODS OF STUDYING BACTERIA (Continued),— 
 SOLUTIONS AND FORMULAS FOR STAINING 
 
 Staining or coloring bacteria is done in order to make them 
 prominent and to obtain permanent specimens. It is also 
 necessary to bring out the structure of the bacteria, and 
 serves in many instances as a means of diagnosis ; it would be 
 well-nigh impossible to discover them in the tissues without 
 staining. 
 
 Anilin Colors. — Of the numerous dyes in the market, 
 nearly all have, at one time or other, been used in staining 
 
48 ESSENTIALS OF BACTERIOLOGY 
 
 bacteria. But now only a very few find general use, and with 
 methylene-blue and fuchsin nearly every object can be 
 accomplished. 
 
 Basic and Acid Dyes. — Ehrlich was the first to divide the 
 anilin dyes into two groups, the basic colors to which belong — 
 Gentian-violet, or pyoktanin. Basic fuchsin. 
 
 Methyl- violet, or dahlia. Bismarck-brown 
 
 Methylene-blue {not methyl blue). Thionin. 
 Safranin. 
 And the acid colors to which eosin and acid fuchsin belong. 
 
 The basic anilme dyes stain the bacteria and the nuclei of 
 cells; the acid dyes stain chiefly the tissue, leaving the bac- 
 teria almost untouched. Carmin and hematoxylin are also 
 useful as contrast stains, affecting bacteria very slightly. The 
 anilin dyes are soluble in alcohol or water or a mixture of the 
 two. 
 
 Staining Solutions. — A saturated solution of the dye is 
 made with alcohol. This is called the stock or concentrated 
 solution; i part of this solution to about lo parts of distilled 
 water constitutes the ordinary aqueous solution in use or 
 weak solution. 
 
 It is readily made by adding to an ounce bottle of distilled 
 water enough of the strong solution until the fluid is still 
 opaque in the body of the bottle, but clear in the neck of the 
 same. 
 
 These weak solutions should be renewed every three or four 
 weeks, otherwise the precipitates formed will interfere with 
 the staining. 
 
 Compound Solutions. — By means of certain chemic 
 agents the intensity of the anilin dyes can be greatly increased. 
 
 Intensifiers or Mordants. — Agents that ''bite'' into the 
 specimen, carrying the stain with them, depositing it in the 
 deeper layers, are called mordants or etchers. 
 
 Various metallic salts and vegetable acids are used for such 
 purpose. 
 
 The mother liquid of the anilin dyes, anilin-oil, a member 
 of the aromatic benzol group, has also this property. 
 
METHODS OF STUDYING BACTERIA 49 
 
 Anilin-oil Water. — Anilin-oil is shaken up with water and 
 then filtered; the aniUn water so obtained is mixed with the 
 dyes, forming the "aniUn- water gentian- violet " or anilin- 
 water fuchsin, etc. 
 
 Carbolfuchsin. — Carbolic acid or phenol can be used 
 instead of anilin-oil, and forms one of the main ingredients of 
 Ziehl's or Neelsen's solution, used principally in staining 
 Bacillus tuberculosis. Kuhne has a carbol-methylene-blue 
 made similar to the carbolfuchsin. 
 
 Alkaline Stains. — Alkalis have the same object as the 
 above agents, namely, to intensify the picture. Potassium 
 hydroxid, ammonium carbonate, and sodium hydroxid are 
 used. 
 
 Loffler's alkaline blue and Koch's weak alkaline blue are 
 made with potassium. 
 
 Heat. — Warming or boiling the stains during the process 
 of staining increases their intensity. 
 
 Decolorizing Agents. — The object after staining is usu- 
 ally overcolored in some part, and then decolorizing agents are 
 employed. Water is sufficient in many cases; alcohol and 
 strong mineral acids combined are necessary in some. 
 
 lodin as Used in Gram's Method. — Belonging to this 
 group, but used more in the sense of a protective, is tincture 
 of iodin. It picks out certain bacteria, which it coats; pre- 
 vents them from being decolorized, but fades the rest of the 
 picture. Then, by using one of the acid or tissue dyes, a con- 
 trast color or double staining is obtained. Many of the more 
 important bacteria are not acted upon by the iodin, and it 
 thus becomes a very useful means of diagnosis. 
 
 FORMULAS OF DIFFERENT STAINING SOLUTIONS 
 
 I. Saturated Alcoholic Solution 
 
 Place about lo grams of the powdered dye in a bottle and 
 add 40 grams of alcohol. Shake well and allow to settle. 
 This can be used as the stock bottle. 
 
5© ESSENTIALS OF BACTERIOLOGY 
 
 II. Weak Solutions 
 Made by adding about i part of stock solution (I) to lo 
 parts of distilled water. This is the ordinary solution in use. 
 
 III. Anilin-oil Water 
 
 Anilin-oil 5 parts 
 
 Distilled water 100 " — M. 
 
 Shake well and filter. To be made fresh each time. 
 
 IV. Anilin-oil Water Dyes 
 Saturated alcoholic solution of the 
 
 dye II parts 
 
 Anilin-oil water 100 '* 
 
 Absolute alcohol 10 " — M. 
 
 Can be kept ten days. 
 
 V. Alkaline Methylene-blue 
 
 A. Lqffler^s: 
 
 Saturated alcoholic solution methy- 
 lene-blue 30 parts 
 
 Solution potassium hydroxid (i per 
 
 cent.) I part 
 
 Water. q. s. 100 parts — M. 
 
 B. Koch's: 
 
 Solution potassium hydroxid (10 per 
 cent.) 2 parts 
 
 Saturated alcoholic solution methy- 
 lene-blue 10 " 
 
 Distilled water 2000 " — M. 
 
 VI. Phenol Solutions 
 
 A. Ziehl-N eelsen: 
 
 Fuchsin (powdered) i part 
 
 Alcohol 10 parts 
 
 5 per cent, solution phenol 100 " — M. 
 
 Filter. The older the solution, the better. 
 
METHODS OF STUDYING BACTERIA 5I 
 
 B. Kiihne: 
 
 Methylene-blue 1.5 parts 
 
 Alcohol lo.o '' 
 
 5 per cent, solution phenol loo.o " 
 
 Add the phenol gradually. This solution loses strength 
 with age. 
 
 VII. Gramas lodin Solution 
 
 lodin I part 
 
 Potassium iodid 2 parts 
 
 Distilled water 300 " — M. 
 
 VIII. Lqffler^s Mordant {for Flagella) 
 Aqueous solution of tannin (20 per 
 
 cent.) 10 parts 
 
 Aqueous solution ferric sulphate (5 
 
 per cent.) i part ■ 
 
 Aqueous decoction of logwood (1:8) 4 parts. — M. 
 Keep in well-corked bottle. 
 
 IX. Unna's Borax Methyl-blue 
 
 Borax i part 
 
 Methyl blue i " 
 
 Water 100 parts. — M. 
 
 X. Gabbefs Acid Blue {Rapid Stain) 
 Methylene-blue 2 parts 
 
 20 per cent, sulphuric acid 100 " — M. 
 
 XI. Alkaline Anilin-water Solutions 
 Sodium hydroxid (i per cent.) .... i part 
 Anilin-oil water 100 parts. — M. 
 
 And add — 
 
 Fuchsin, or methyl-violet powdered 4 parts 
 Cork well. Filter before using. 
 
52 ESSENTIALS OF BACTERIOLOGY 
 
 XII. Roux^s Double Stain 
 
 Dahlia or gentian- violet 0.5 part 
 
 Methyl-green 1.5 parts 
 
 Distilled water 200.0 " — M. 
 
 Use as other stains, without acid. 
 
 XIII. Neisser^s Stain {for Diphtheria) 
 Solution I 
 
 Methylene-blue i part 
 
 Alcohol (96 per cent.) 20 parts 
 
 Dissolve and add — 
 
 Water 950 parts 
 
 Glacial acetic acid 50 " — M. 
 
 Solution II 
 
 Vesuvin 2 parts 
 
 Water 1000 " — M. 
 
 Stain cover-glasses — (i) Three seconds in solution I; (2) 
 wash in water; (3) three seconds in No. II; (4) wash in water. 
 Body of bacillus, brown; oval granules at each end, blue. 
 
 XIV. Carholthionin {Nicolle) 
 Saturated solution thionin in alcohol 
 
 (90 per cent.) 10 parts 
 
 Aqueous solution phenol (i per 
 
 cent.) 100 " — M. 
 
 Stain sections one-half to one minute. 
 
 XV. Capsule Stain of Hiss 
 Use the following, heated until it 
 steams: Saturated alcoholic solu- 
 tion of gentian- violet or f uchsin . . 5 parts 
 
 Distilled water 95 " — M. 
 
 Wash in 20 per cent, solution of cupric sulphate crystals. 
 
METHODS OF STUDYING BACTERIA 53 
 
 XVI. Capsule Stain of Welch 
 (i) Pour glacial acetic acid on film. After a few seconds 
 replace with anilin-water gentian-violet without washing in 
 water. (2) Remove all acid by several additions of stain, 
 and allow it to act for three to four minutes. (3) Wash and 
 examine in salt solution 0.8-2.0 per cent. 
 
 XVII. Romanowsky Stains 
 
 A compound dye originally used for malarial parasites, but 
 now employed in some of its modifications in staining blood- 
 films, bacteria in tissues, and protozoa generally. 
 
 The stain is difficult to prepare, and can be purchased of 
 supply houses to better advantage. 
 
 The chief modifications are: 
 
 Leishman^s stain, consisting of a i per cent, solution methyl- 
 ene-blue, to which 0.5 per cent, sodium carbonate has been 
 added and allowed to stand for twelve hours in incubator at 
 65° C, and then ten days at room temperature, and a solu- 
 tion of eosin (i: 1000) in water. Equal parts of these solu- 
 tions are mixed and allowed to stand for six hours. After it 
 has been washed and dried, the precipitate is dissolved in 
 methyl-alcohol. 
 
 Giemsa Stain: 
 
 Azur II. — eosin 3 parts 
 
 Azur II 8 '' 
 
 Glycerin (pure) 250 " 
 
 Methyl-alcohol 250 " — M. 
 
 Azur is a mixture of methylene-blue and eosin prepared in 
 a special way. 
 
 Jenner^s Stain. — 1.2 per cent, aqueous solution of water- 
 soluble eosin; i per cent, aqueous solution methylene-blue 
 (Grubler) ; equal parts of each. Mix; allow to stand twenty- 
 four hours, wash the precipitate, dry it, dissolve 0.5 gm. in 
 100 c.c. methyl-alcohol. 
 
 /. H. Wright's Stain. — Made in much the same way as 
 Leishman's. The precipitate is not washed, but the satur- 
 
54 ESSENTIALS OF BACTERIOLOGY 
 
 ated methyl-alcohol solution is filtered and further diluted 
 with methyl-alcohol. The stains are used in very dilute 
 form. Where the blood-films or exudates are not first fixed 
 in alcohol, the concentrated stain is allowed to cover the 
 preparation for five to twenty seconds to fijc; then water is 
 poured on to dilute and from five to fifteen minutes allowed 
 for staining, the excess removed with water. The stains can 
 be purchased in powder or tablet form, and need only be 
 mixed with methyl-alcohol to be ready for use. 
 
 CHAPTER VII 
 GENERAL METHOD OF STAINING SPECIMENS 
 
 Cover-glass Preparations. — ^The material is evenly 
 spread in as thin a layer as possible upon a cover-glass; then, 
 to spread it still more finely, a second cover-glass is pressed 
 down upon the first and the two slid apart. This also secures 
 two specimens. Before they can be stained, they must be 
 perfectly dry, otherwise deformities will arise in the structure. 
 
 Drying the Specimen. — The cover-glass can be set aside 
 to dry, or held in the fingers over the Bunsen burner (the 
 fingers preventing too great a degree of heat). Since most of 
 the specimens contain a certain amount of albuminoid mater- 
 ial, it is best in all cases to "fix" — i. e., to coagulate the 
 albumin. This is accomplished by passing the cover-glass 
 (after the specimen is dry) three times through the flame of 
 the burner, about three seconds being consumed in so doing, 
 the glass being held in a small forceps, smeared side up. 
 
 The best forceps for grasping cover-glasses is a bent one, 
 bent again upward, near the ends (Fig. 13). It prevents the 
 flame or staining fluid from reaching the fingers. 
 
 The object is now ready for staining. 
 
 Staining. — A few drops of the staining solution are placed 
 
GENERAL METHOD OF STAINING SPECIMENS 55 
 
 upon the cover-glass so that the whole specimen is covered, 
 and the stain is left on a few minutes, the time depending 
 upon the variety, the strength of stain, and the object de- 
 sired. Instead of placing the dye upon the object, the cover- 
 glass can be immersed in a small glass dish containing the 
 solution; or, if heat is desired to intensify or hasten the proc- 
 ess, a watch-crystal holding the stain is placed over a Bun- 
 sen burner and in it the cover-glass ; the cover-glass may be 
 held directly in the flame with the staining fluid upon it, 
 which must be constantly renewed until the process is com- 
 pleted, or the cover-glass can be heated in a test-tube, con- 
 taining stain solution. 
 
 Removing Excess of Stain. — The surplus stain is washed 
 off by dipping the glass in distilled water. 
 
 Fig. 13. — Author's bent forceps for holding cover-glass over flame. 
 
 The water is removed by drying between filter-paper or 
 simply allowed to run off by standing the cover-glass slant- 
 wise against an object. When the specimen is to be examined 
 in water (which is always best with the first preparation of 
 the specimen, as the Canada balsam destroys to some extent 
 the natural appearance of the bacteria) , a small drop of ster- 
 ilized water is placed upon the glass slide, and the cover-glass 
 dropped gently down upon it, so that the cover-glass remains 
 adherent to the slide. 
 
 The dry system or the oil immersion can now be used. 
 
 When the object has been sufiiciently examined, it can be 
 permanently mounted by lifting the cover-glass off the slide 
 (this is facilitated by letting a little water flow under it, one 
 
56 ESSENTIALS OF BACTERIOLOGY 
 
 end being slightly elevated). The water that still adheres 
 is dried off in the air or gently over the flame, and when per- 
 fectly dry, the cover-glass is placed upon the drop of Canada 
 balsam which has been put upon the glass sHde. 
 
 In placing the cover-glass in the staining solutions one 
 must be careful to remember which is the spread side, by 
 holding it between one's self and the window and scraping the 
 sides carefully with the sharp point of the forceps, the side 
 having the specimen on it will show the marks of the instru- 
 ment. 
 
 Little glass dishes, about one-half dozen, should be at hand 
 for containing the various stains and decolorants. 
 
 Tissue Preparations. — In order to obtain suitable speci- 
 mens for staining, very thin sections of the tissue must be 
 made. 
 
 As with histologic preparations, the tissue must be hardened 
 before it can be cut thin enough. Alcohol is the best agent 
 for this purpose. 
 
 Pieces of the tissue one-quarter inch in size are covered with 
 alcohol for twenty-four to forty-eight hours. 
 
 When hardened, it must be fixed upon or in some firm 
 object. A paste composed of — 
 
 Gelatin i part 
 
 Glycerin 4 parts 
 
 Water 2 " 
 
 will make it adhere firmly to a cork in about two hours, or it 
 can be embedded in a small block of paraffin and covered 
 over with melted paraffin. Celloidin may be used as an 
 embedding agent, and formalin is useful to harden tissue 
 quickly. 
 
 Cutting. — ^The microtome should be able to cut sections 
 Tutu inch in thickness; this is the fineness usually required. 
 
 The sections are brought into alcohol as soon as cut, unless 
 they have been embedded in paraffin, when they are first 
 washed in chloroform to dissolve out the paraffin. 
 
GENERAL METHOD OF STAINING SPECIMENS 57 
 
 Staining. — All the various solutions should be in readiness, 
 best placed in the little dishes in the order in which they are to 
 be used, as a short delay in one of the steps may spoil the 
 specimen. 
 
 A very useful instrument for transferring the deHcate 
 sections from one solution to another is a little metal spatula, 
 the blade being flexible (Fig. 14). 
 
 A still better plan, especially when the tissue is ''crum- 
 bling," is to carry out the whole procedure on the glass slide. 
 
 General Principles. — The section is transferred from the 
 alcohol in which it has been kept into water, which removes 
 the excess of alcohol, from here into — 
 
 Dish /, containing the stain, where it remains five to fifteen 
 minutes. Then — 
 
 Dish II, containing 5 per cent, acetic acid (1:20), where it 
 
 Spatula for lifting sections. 
 
 remains one-half to one minute. The acid removes the 
 excess of stain. 
 
 Dish III, water, to rinse off the acid. The section can now 
 be placed under the microscope, covered with cover-glass to 
 see if the intensity of the stain is sufficient or too great. A 
 second section is then taken, avoiding the errors, if any; and 
 having reached this stage, proceeded with as follows: 
 
 Dish IV, alcohol, two to three seconds, to remove the water 
 in the tissue. 
 
 V. A few drops of oil of cloves, just long enough to clear the 
 specimen to make it transparent (so that an object placed 
 underneath will shine through). 
 
 VI. Remove excess with filter-paper. 
 
 VII. Mount in Canada balsam (xylol balsam). 
 Staining Blood Specimens. — A drop of blood is spread on 
 
58 ESSENTIALS OF BACTERIOLOGY 
 
 a cover-glass and stained with the ordinary dyes ; but in order 
 to eliminate the coloring-matter of the red corpuscles and 
 bring the stained bacteria more prominently into view, 
 Gunther recommends that the blood, after drying and fixing, 
 should be rinsed in a dilute solution of acetic acid (i to 5 per 
 cent.). The hemoglobin is thereby extracted, and the cor- 
 puscles appear then only as faint outlines. 
 
 Instead of "fixing" by heat, Canon employs alcohol for five 
 minutes, especially in staining for influenza bacilli which have 
 been detected in the blood. 
 
 CHAPTER VIII 
 
 SPECIAL METHODS OF STAINING AND MODIFICATIONS 
 
 Gram's Method of Double Staining {For Cover-glass 
 Specimens). — I. A hot solution of anilin- water gentian- violet 
 two to ten minutes. 
 
 II. Directly, without washing, into Gram's solution of 
 iodin potassium iodid one to three minutes (the cover-glass 
 looks black). 
 
 III. Wash in alcohol 60 per cent, until only a light brown 
 shade remains (as if the glass were smeared with dried blood). 
 
 IV. Rinse off alcohol with water. 
 
 V. Contrast color with either eosin, picrocarmin, or Bis- 
 marck-brown. The bacteria will appear deep blue, all else 
 red or brown on a very faint brown background. 
 
 Gram's Method for Tissues {Modified by Gunther) 
 I. Stain in anilin- water gentian- violet . . i minute 
 II. Dry between filter-paper. 
 
 III. Iodin potassium iodid solution 2 minutes 
 
 IV. Alcohol i^ minute 
 
 V. 3 per cent, solution hydrochloric acid 
 
 in alcohol 10 seconds 
 
 VI. Alcohol, oil of cloves, and Canada balsam. 
 
SPECIAL METHODS OF STAINING AND MODIFICATIONS 59 
 
 Behavior of the More Important Bacteria to Gram's Stain. — 
 Positive means that the bacteria retain the primary color, or 
 gentian- violet; negative, that they do not. 
 
 Positive. Negative. 
 
 Tubercle bacillus. Colon bacillus. 
 
 Smegma bacillus. Typhoid bacillus. 
 
 Lepra bacillus. Cholera bacillus. 
 
 Anthrax bacillus. Influenza bacillus. 
 
 Tetanus bacillus. Friedlander's bacillus. 
 
 Diphtheria bacillus. Plague bacillus. 
 
 Pneumococcus. Diplococcus intracellularis. 
 
 Streptococcus. Gonococcus. 
 
 Staphylococcus. Koch- Weeks bacillus. 
 
 Cocci of the urethra. Conjunctivitis bacillus of Morax. 
 
 Loffler's Method for Tissues 
 
 Alkaline methylene-blue 5~30 minutes 
 
 I per cent, acetic acid few seconds. 
 
 Absolute alcohol, xylol, Canada balsam. 
 Bacteria dark blue, nuclei blue, cell-bodies light blue. 
 
 To Stain Spores. — Since spores have a very firm capsule, 
 which tends to keep out all external agents, a very intensive 
 stain is required to penetrate them, but once this object is 
 attained, it is equally as difficult to decolorize them. 
 
 A cover-glass prepared in the usual way, i. e., drying and 
 passing the specimen through the flame three times, is placed 
 in a watch-crystal containing Ziehl's carbolfuchsin solution, 
 and the same placed upon a rack over a Bunsen burner, where 
 it is kept at boiling-point for one hour, careful to supply fresh 
 solution at short intervals lest it dry up. 
 
 The bacilli are now decolorized in alcohol containing 0.5 
 per cent, hydrochloric acid. A contrast color, preferably 
 methylene-blue, is added for a few minutes. 
 
6o ESSENTIALS OF BACTERIOLOGY 
 
 The spores will appear as little red beads in the blue-stained 
 bacteria, and loose spores lying about outside the cell-wall. 
 
 Spore Stain {Modified). — I. Carbolfuchsin on cover-glass 
 and heated in the flame to boiling-point 20 to 30 times. 
 
 II. 25 per cent, sulphuric acid, two seconds; rinsed in 
 water. 
 
 III. Methylene-blue contrast. 
 
 Alex. Klein recommends the following spore method: mix a 
 little of the culture (potato) with three drops of physiologic 
 salt solution, and heat gently with an equal quantity of 
 carbolfuchsin for a period of six minutes. Spread then on 
 cover-glasses, dry in the air, and fix by passing three times 
 through Bunsen-burner flame. Decolorize in i per cent, 
 sulphuric acid for one to two seconds; contrast in weak 
 methylene-blue. 
 
 Bowhill's Orcein Stain 
 
 Saturated alcoholic solution of orcein . 15 c.c. 
 
 20 per cent, aqueous solution tannin . 10 c.c. 
 
 Distilled water 30 c.c. — M. 
 
 Filter. 
 
 Use orcein solution in watch-glass, float cover-glass in it, 
 and heat gently, not boil, for ten minutes. Wash in water. 
 Dry and mount in balsam. 
 
 Five per cent, chromium trioxid applied for fifteen minutes 
 has been recommended in staining spores. This is followed 
 by the carbolfuchsin stain as above. 
 
 Sporogenic bodies stain quite readily, and in order to distin- 
 guish them from spores Ernst uses alkaline methylene-blue, 
 slightly warmed. Then rinse in water. Contrast with cold 
 Bismarck-brown. The spores are colored bright blue, the 
 spore granules a dirty blue, being mixed with the brown, 
 which colors also the bacteria. 
 
 Kuhne's Method.— In sections the alcohol used sometimes 
 decolorizes too much. To obviate this Kuhne mixes the alco- 
 
SPECIAL METHODS OF STAINING AND MODIFICATIONS 6l 
 
 hol with the stain, so that while the section is being anhy- 
 drated, it is constantly supplied with fresh dye. 
 
 Weigert uses anilin-oil to dehydrate instead of alcohol, and 
 here, too, it can be used mixed with the dye. 
 
 Capsule Stain {Buerger). — I. Spread culture by means of 
 a drop of ascitic fluid on cover-glass. 
 
 II. Fix in Miiller's fluid, which has been saturated with 
 5 per cent, bichlorid of mercury, and warm for three seconds. 
 
 III. Wash quickly in water; rinse in alcohol. 
 
 IV. Cover with tincture of iodin for one minute. 
 V. Wash in alcohol and dry in air. 
 
 VI. Stain in anilin-water gentian-violet for two seconds. 
 VII. Wash in 2 per cent, salt solution. 
 
 VIII. Mount in salt solution ringed with vaselin. 
 
 Hiss* Method for Capsule. — Smear on cover-glass the 
 organisms mixed with a drop of animal serum (beef-blood 
 serum or ascitic fluid). Dry in air. Fix by heat. Stain for 
 few seconds in Hiss' stain (p. 52). Wash in 20 per cent, cop- 
 per sulphate solution. Dry and mount. Capsule appears 
 as faint blue halo about dark-purple cell. 
 
 Flagella Stain, with Loffler's Mordant. — I. A few drops 
 of the mordant stain (p. 51) are placed upon the spread 
 cover-glass and heated until it steams. 
 
 II. Wash with water until the cover-glass looks almost 
 clean, using a small piece of filter-paper to rub off the crusts 
 which have gathered around the edges. 
 
 III. Anilin-water fuchsin (neutral) held in flame about one 
 and one-half minutes. 
 
 IV. Wash in water. 
 
 If the stain is properly made, the bacteria are deeply 
 colored and the flagella seen as little dark lines attached to 
 them. 
 
 Unna's Method for Fungi. — Especially useful for epi- 
 dermic scales. Moisten horny scale or crust with acetic acid; 
 macerate between two glass slides; dry in flame; wash out fat 
 with ether and alcohol (equal parts) ; stain in horax methyl-hlue 
 
62 ESSENTIALS OF BACTERIOLOGY 
 
 for ten seconds (over flame) ; bleach with glycerin and ether 
 (equal parts) ; rinse in water, alcohol, dry, and mount. 
 
 CHAPTER IX 
 CULTIVATION OF BACTERU 
 
 Artificial Cultivation. — The objects of cultivation are to 
 obtain germs in pure culture, free from all foreign matter, 
 isolated, and so developed as to be readily used either for 
 microscopic examination or animal experimentation. 
 
 To develop bacteria properly we supply, as nearly as possi- 
 ble, the conditions which hold for the especial germ in nature. 
 With the aid of solid nutrient media the bacteria can be easily 
 separated, and the methods have been gradually evolved 
 from those originally devised by Pasteur and Koch. 
 
 Sterilization of Culture-media, etc. — If we place our 
 nutrient material in vessels that have not been properly dis- 
 infected, we will obtain growths of bacteria without having 
 sown any. 
 
 If we have thoroughly cleaned our utensils and then not 
 taken care to protect them from further exposure, the germs 
 we have sown will be effaced or contaminated by multitudes 
 of others that are constantly about us. We, therefore, have 
 two necessary precautions to take: 
 
 First, thoroughly to clean and sterilize every object that enters 
 into, or in any way comes in contact with, the culture. 
 
 Second, to maintain this degree of sterility throughout the 
 phole course of the growth, and prevent, by proper containers, 
 the entrance of foreign germs. 
 
 Disinfectants. — Corrosive sublimate (bichlorid of mercury), 
 which is the most effective agent we possess, cannot be gener- 
 ally used because it renders the soil unproductive, and, there- 
 fore, must be employed only in washing dishes, to destroy the 
 
CULTIVATION OF BACTERIA 
 
 63 
 
 old cultures. Even after washing a few drops of the solution 
 may remain and prevent growth, so that one must be careful 
 to have the glassware that comes in contact with the nutrient 
 media free from the sublimate. 
 
 Fig. 15. — Hot-air sterilizer. The gas-jets are inclosed within the 
 space between the outer and middle walls, C, and can be seen at F. The 
 heat ascends, warming the air between the two inner walls, which ascends 
 between the walls, K, K, then descends over the contents,/, and escapes 
 through perforations in the bottom, B, to supply the draft at F, and 
 eventually escapes again at S; R, gas regulator; T, thermometer. 
 
 Heat. — Heat is the best agent we possess for general use. 
 Dry heat and moist heat are the two forms employed, but 
 these differ greatly in effectiveness. Thus Koch found that 
 
64 ESSENTIALS OF BACTERIOLOGY 
 
 while moist heat at ioo° C. killed the spores of the anthrax 
 bacillus in one hour, it required three hours of dry heat at 
 140° C. to produce death. 
 
 For obtaining dry heat — that is, a temperature of 150° C. 
 (about 300° F.) — a sheet-iron oven (Fig. 15) is used which 
 can be heated by a gas-burner. If it have double walls (air 
 circulating between), the desired temperature is much more 
 quickly obtained. A small opening in the top to admit a 
 thermometer is necessary. These chests are usually about 
 I foot high, i}i feet wide, and ^ foot deep. In them glass- 
 ware, cotton, and paper can be sterilized. When the cotton 
 is turned slightly brown, it usually denotes sufficient steriliza- 
 tion. All instruments, where practicable, should be drawn 
 through the flame of an alcohol lamp or Bunsen burner. One 
 hour in the oven at 170° C. usually sterihzes glassware, while 
 the ordinary germs in Hquids may be killed by boiling for 
 five minutes if no spores are present. The boiling of any 
 fluid at 100° C. for one and one-half hours nearly always 
 insures sterilization. 
 
 Moist Heat. — Steam at 100° C. in circulation has been 
 shown to be a very effective application of heat. 
 
 The steam chest devised by Koch consisted of a long 
 double boiler divided by a perforated shelf on which the 
 material could rest while subjected to streaming steam. 
 
 Arnold's steam sterilizer will answer every purpose of the 
 Koch steam-chest. It is cheaper, also requiring less fuel to 
 keep it going. The steam does not escape, but is condensed 
 in the outer chamber. 
 
 The autoclave (Fig. 16), which produces steam under 
 pressure and allows a temperature of 120° C. to be obtained, 
 is a most effective method of sterilization, but the higher 
 temperatures are not suitable for gelatin or sugar solution. 
 Gelatin loses its power of solidifying if the boiling is pro- 
 longed. 
 
 Instead of sterilizing for a long time at once, successive 
 sterilization is practised with nutrient media, so that the 
 albumin will not be too strongly coagulated. Fifteen minutes 
 
CULTIVATION OF BACTERIA 
 
 6s 
 
 each day for three days in succession in the Arnold sterilizer, 
 or one exposure in the autoclave, five to fifteen minutes, at 
 15 pounds pressure; 120° C. is sufficient to sterilize most 
 culture-media. 
 
 Fractional Sterilization of T3mdall. — Granted that so 
 many spores originally exist in the object to be sterilized, it 
 
 ^ li 
 
 Fig. 16. — Autoclave. Horizontal form. 
 
 is subjected to 60° C. for four hours, in which time a part at 
 least of those spores have developed into bacteria, and the 
 bacteria destroyed by the further application of the heat. 
 The next day more bacteria will have formed, and four 
 hours' subjection to 60° C. heat will destroy them, and so, 
 at the end of a week, using four hours' application each day, 
 all the spores originally present will have germinated and the 
 bacteria be destroyed. 
 5 
 
66 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 As modified, and in use in most laboratories, fifteen minutes, 
 sterilization in steam, at ioo° C, in the Arnold sterilizer on 
 three successive days, has been found sufficient, while one 
 steriHzation in the autoclave at 120° C. for fifteen minutes 
 will serve in most cases, especially if the medium is for imme- 
 diate use, and does not contain gelatin or sugar. 
 
 Cotton Plugs or Corks. — All the glass vessels (test-tubes, 
 flasks, etc.) must be closed with cotton plugs, cotton-wool, 
 
 Fig. 17. — ^Wire cage. Fig. 18. — Cotton-plugged test-tubes. 
 
 or a good quality of non-absorbent cotton), the cotton being 
 easily sterilized and preventing the entrance of germs from 
 the air. 
 
 Tin-foil may be used to cover the cotton, or caps made of 
 india-rubber. 
 
 Test-tubes. — New test-tubes are washed with hydro- 
 chloric acid and water to neutralize the alkalinity often pres- 
 ent in fresh glass, or in chromic acid cleaning mixture one 
 hour. (Potassium dichromate, 6; water, 30; sulphuric acid, 
 46.) They are then well washed and rubbed with a brush, 
 
PREPARATION OF NUTRIENT CULTURE-MEDIA 67 
 
 placed obliquely to drain, and when dry, corked with cotton 
 plugs. Then put in the hot-air oven (little wire cages, Fig. 
 17, being used to contain them) for fifteen minutes, after 
 which they are ready to be filled with the nutrient mediiun. 
 (The cotton should fit firmly in the tube and extend a short 
 space beyond it.) 
 
 Test-tubes without flaring edges are more desirable, since 
 the edges can easily be drawn out so as to seal the tube. 
 
 Instead of test-tubes, ordinary 3-ounce panel medicine 
 bottles can be used for retaining the nutrient media and 
 cultures. 
 
 According to investigations, the glass tubes become suffi- 
 ciently sterile in the steam-chest without the preliminary 
 sterilization in the dry oven. 
 
 Sterilization by Filtration. — Germ Filters. — Kaolin or por- 
 celain bougies, such as are used in the Berkefeld, Chamber- 
 land, and Pasteur filters, restrain most bacteria, except those 
 now known as ultramicroscopic. In the making of toxins 
 this method is used, heat or disinfectants being undesirable. 
 With the knowledge of smaller forms of life, the filter will 
 need further improvement. 
 
 CHAPTER X 
 PREPARATION OF NUTRIENT CULTURE-MEDU 
 
 Of the many different media recommended and used since 
 bacteriology became a science, we can describe only the more 
 important ones now in use. Each investigator changes them 
 according to his taste. 
 
 Potato as Medium. — The knowledge of bacteria and 
 germs or molds settling and growing upon slices of potato 
 
68 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 exposed to the air led to the use of solid media for the 
 artificial culture of the same. It was thus learned that each 
 germ tends to form a separate colony and remain isolated, 
 and so pure cultures were first obtained. 
 
 Esmarch's Cubes. — ^The potato is first well cleaned and 
 peeled. It is then cut in cubes Yi inch in size. 
 
 These are placed, each in a little glass dish or tray, and then 
 in steam-chest for one-half hour, after which they are ready 
 for inoculation (the dishes first having been 
 sterilized in hot-air oven). 
 
 Test-tube Potatoes. — Cones are cut out 
 of the peeled potato and placed in test-tubes, 
 which can then be plugged and easily pre- 
 served. 
 
 Roux's test-tube (Fig. 19), specially de- 
 signed for potato cultures, consists of a tube 
 with a small constricted portion at the bot- 
 tom, in which water may be kept to keep the 
 potato moist. 
 
 Manner of Inoculating Potatoes. — With 
 a platinum rod or a spatula (sterilized) the 
 material is spread upon one of the slices, 
 keeping free of the edges. The growth on 
 this first, or original, potato will be quite lux- 
 uriant, and the individual colonies often diffi- 
 cult to recognize; therefore dilutions are made. 
 From the original or first slice a small portion, including 
 some of the meat of the potato, is spread upon the surface of 
 a second slice, which is first dilution. From this likewise a 
 small bit is taken and spread on a third slice, or second dilu- 
 tion, and here usually the colonies will be sparsely enough 
 settled to study them in their individuality. 
 
 This is the principle carried on in all the cultivations. It 
 is a physical analysis. 
 
 Potato and Bread Mash. — These pastes are used chiefly 
 in the culture of molds and yeasts. Peeled potatoes are 
 mashed with distilled water until thick, and then sterilized 
 
 Fig. 19. — Tube 
 for potato cul- 
 ture. 
 
PREPARATION OF NUTRIENT CULTURE-MEDIA (ig 
 
 in flasks three-quarters of an hour for three successive 
 days. 
 
 Bread Mash. — Bread devoid of crust, dried in an oven, and 
 then pulverized and mixed with water until thick, and steril- 
 ized as above. 
 
 Solid transparent media are prepared from materials 
 which are transparent and which can readily be converted 
 into liquids. Such are the gelatin and agar culture-media. 
 
 Gelatin. — Gelatin is obtained from bones and tendons, 
 and consists chiefly of chondrin and gluten. 
 
 Agar-agar. — This agent, which is of vegetable origin, 
 derived from sea-plants gathered on the coasts of India and 
 Japan, has many of the properties of gelatin, retaining its 
 solidity at a much higher temperature; it becomes liquid at 
 90° C. and congeals again at 45° C. (gelatin will liquefy at 
 35° C), whereas 38° C. is the temperature at which most 
 pathogenic germs grow best. Agar cultures can be kept in 
 incubator for days and weeks without liquefying. 
 
 Agar is not affected very much by the peptonizing action 
 of the bacteria. 
 
 The crude agar should first be rinsed in water, and then in 
 5 per cent, acetic acid and clear water again, to rid it of im- 
 purities. If agar is boiled thoroughly over a hot flame or in 
 an autoclave, it can be filtered much more readily. The 
 main point is to see that all the agar is dissolved. 
 
 Glycerin-agar. — The addition of 4 to 6 per cent, of gly- 
 cerin to nutrient agar greatly enhances its value as a culture- 
 medium. 
 
 Gelatin-agar. — A mixture of 5 per cent, gelatin and 0.75 
 per cent, agar combines in it some of the virtues of both 
 agents. 
 
 Blood-servun. — Blood-serum, being rich in albumin, co- 
 agulates very easily at 70° C, and if this temperature is not 
 exceeded, a transparent solid substance is obtained upon 
 which the majority of bacteria develop, and some with 
 preference. 
 
70 ESSENTIALS OF BACTERIOLOGY 
 
 PREPAIIATION OF NUTRIENT CULTURE-MEDIA 
 
 (After the recommendations of the American Public Health Association) 
 
 Materials. — All water used should be distilled. 
 Fresh meat. 
 
 Dried peptone, Witte brand. 
 
 Best French gelatin, as free as possible from impurities. 
 Best commercial agar in threads. 
 Sugars, dextrose, lactose, and saccharose, all chemically 
 
 pure. 
 Glycerin, double distilled. 
 Azolitmin in place of litmus. 
 All other materials as nearly as possible chemically pure. 
 
 Sterilization. — Preferably in the autoclave and in small 
 containers, at 120° C.,with 15 pounds pressure for fifteen 
 minutes. The sterilizer should be hot before the medium 
 is put in. 
 
 Intermittent. — For gelatin or sugar media a high tempera- 
 ture is not suitable. The media are placed in streaming 
 steam for thirty minutes on three successive days. 
 
 Reaction. — One-half per cent, solution phenolphthalein 
 (5 grams to i liter alcohol) is needed as an indicator. 
 The reaction should be -f-i per cent., i. e., 1 per cent, 
 alkaline solution required to make it neutral. 
 
 Method of Obtaining Reaction. — To 5 c.c. of medium add 
 45 c.c. water. Boil one minute. Add i c.c. solution 
 phenolphthalein. If the mixture is not tinted pink, the 
 medium is acid or neutral and requires the gradual addi- 
 tion of I : 20 normal sodium hydroxid solution until a 
 faint pink color remains. The soda should be added 
 while the mixture is hot or boiling. Calculate from the 
 amount of alkali used for the 5 c.c. how much will be 
 needed for the whole quantity of media and add the 
 same, using normal solution instead of i : 20 normal. 
 Example: If 2 c.c. - NaOH will neutralize 5 c.c. media, 
 
 N N 
 
 2 c.c. Y NaOH will neutralize 100 c.c, or 20 c.c. - NaOH 
 will neutralize 1000 c.c. media. 
 
 If the medium is very alkaline, hydrochloric acid must be 
 added to reduce to -|- i per cent. 
 
NUTRIENT CULTURE-MEDIA 7 1 
 
 Nitrate Broth. — One gram peptone to one liter water and 
 
 add 0.2 gm. nitrite free potassium nitrate; place ten 
 
 c.c. in test-tube, sterilize in autoclave. 
 Nutrient Broth. — i. Cover i pound (500 gm.) chopped 
 
 meat with 1000 c.c. water and place in refrigerator 
 
 twelve hours. 
 
 2. Strain through Canton-flannel or cheese-cloth and 
 add water to make 1000 c.c. 
 
 3. Add I per cent, peptone, warming until dissolved. 
 
 4. Heat over water-bath thirty minutes. 
 
 5. Restore loss of water. 
 
 6. Titrate and adjust reaction to +1 per cent, by- 
 adding alkali or acid. (See above.) 
 
 7. Boil two minutes over free flame. 
 
 8. Restore loss of evaporation. 
 
 9. Filter through absorbent cotton and Canton-flannel 
 and refilter until clear. 
 
 10. Titrate and record final reaction. If it varies 0.2 
 per cent, from standard, readjust. 
 
 11. Tube, using 10 c.c. in each tube. 
 
 12. Sterilize. 
 
 The nutrient broth as above prepared is used as a basis 
 for most of the other media. It is practically the same 
 as was devised by Lofller in the early days of bacteri- 
 ology. 
 
 Sugar Broths. — Prepared as the standard broth with the 
 addition of i per cent, dextrose, lactose, or other sugar 
 just before final sterilization. 
 
 Nutrient Gelatin. — Ten per cent, gelatin is added with the 
 peptone to the meat-water infusion. Warm gently at 
 60° C. until dissolved, then adjust reaction. Heat 
 over steam-bath for forty minutes. Restore loss of 
 evaporation, readjust reaction, and boil five minutes. 
 Make up loss from evaporation and record final reaction. 
 Filter, tube, and sterilize fifteen minutes in autoclave at 
 120° C. Place at once in ice- water until solid and store 
 in ice-chest. 
 
 Nutrient Agar. — Boil 10 to 15 gm. thread agar in 500 c.c. 
 
72 ESSENTIALS OF BACTERIOLOGY 
 
 water for half-hour or digest in autoclave fifteen minutes. 
 Restore loss by evaporation and allow to cool to 60 c.c. 
 To meat-water infusion (500 parts meat to 500 c.c. 
 water) add 2 per cent, peptone, also 500 c.c. agar solu- 
 tion. Titrate after boiling one minute, and adjust 
 reaction to +1. Heat in steam-bath forty minutes, and 
 proceed as with nutrient gelatin, i. e., restore loss, read- 
 just reaction, and filter and refilter until clear. The 
 filtering should be done while the solution is hot. Pour 
 into tubes or plates, sterilize in au- 
 j^ toclave, and finally slant the tubes 
 
 <^2Si^ so 2-s to obtain a larger surface. 
 
 (Most agar tubes are used for stroke 
 cultures.) 
 
 The addition of the white of an egg 
 will often clear it up; if this avails 
 not, refiltering several times and at- 
 tention to the few points mentioned 
 will produce a clear solution. 
 Lactose Litmus Agar. — One per cent, 
 lactose added to nutrient agar just 
 before sterilization. Reaction neu- 
 tral. One per cent, azolitmin 
 (Kahlbaum) boiled five minutes and 
 
 recdve '°'~Wood-sl- ^^^^^ ^i^^^^ ^^ the tube before final 
 
 mm. sterilization or, if media used in 
 
 plates, added at the time of plating. 
 
 Preparation of Nutrient Blood- sertmi. — If the slaughter 
 of the animal can be supervised, it were best to have the site 
 of the wound and the knife sterilized, and sterile flasks (Fig. 
 20) at hand to receive the blood directly as it flows. 
 
 The blood is placed on ice forty-eight hours, and the 
 serum is drawn out with sterile pipets into test-tubes, avoid- 
 ing shaking of the jar. These are placed obliquely in an 
 oven where the temperature can be controlled and main- 
 tained. (See Fig. 21.) 
 
 Coagulation of Blood-seriun. — The tubes of blood-serum 
 
NUTRIENT CULTURE-MEDIA 73 
 
 having been placed in the thermostat, are kept at a temper- 
 ature of 65° to 68° C. until coagulation occurs; then removed 
 and sterilized by fractional sterilization. 
 
 Sterilization of Blood-serum. — The tubes are placed 
 three to four days in incubator at 58° C, and those tubes 
 which show any evidences of organic growth are discarded. 
 
 If, now, at the end of a week, the serum remains sterile at 
 
 Thermostat or inspissator for blood-serum. 
 
 the ordinary temperature of the room, it can be used for 
 experimental purposes. 
 
 Perfectly prepared blood-serum is transparent, of a gelatin- 
 like consistence, and straw color. It will not liquefy by heat, 
 though bacteria can digest it. Water of condensation 
 always forms, which prevents the drying of the serum. 
 
 Short Method, — Blood-serum may be prepared in a shorter 
 
74 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 way by coagulating the serum at a temperature short of boil- 
 ing-point. Sterilization is completed in three days by expos- 
 ing the tubes to a temperature of about 90° C. each day for 
 five minutes. Tubes so prepared are opaque and white. 
 
 Preservation of Blood-serum in Liquid State. — Kirchner 
 advises the use of chloroform. To a quantity of serum in a 
 
 well-stoppered flask a small 
 amount of chloroform is 
 added — enough to form about 
 a 2 mm. layer on the bot- 
 tom. If the chloroform is 
 not allowed to evaporate, 
 the serum remains sterile 
 for a long time. When 
 needed for use, test-tubes are 
 filled and placed in a water- 
 bath at 50° C. until all chlo- 
 roform has been driven off 
 (determined by absence of 
 characteristic odor) ; the se- 
 rum is then solidified and 
 sterilized as in the ordinary 
 way, or may be used in a 
 fluid state. 
 
 Human Blood-serum. — 
 Blood-serum derived from 
 placenta, serimi from ascitic 
 
 Incubator. 
 
 fluid and ovarian cysts, is 
 
 prepared in a similar manner 
 
 to the above. 
 
 Blood coagulum, suggested by the author, is the blood 
 
 itself (not the serum only) coagulated in test-tubes. It is 
 
 dark brown in color and allows some colonies of bacteria to 
 
 be more visible. It requires less time to prepare, and is not 
 
 so likely to become contaminated as when the serum is used. 
 
 Loffler's Blood-serum Mixture. — To 3 parts clear 
 
 serum add i per cent, glucose, beef infusion, and prepare as 
 
 above; tube. 
 
NUTRIENT CULTURE-MEDIA 75 
 
 Hiss' Medium for Plating 
 
 Agar 15 gin. 
 
 Gelatin 15 " 
 
 Meat extract 5 " 
 
 Sodium chlorid 5 
 
 Dextrose 10 
 
 Distilled water 1000 c.c. 
 
 Digest agar in autoclave, then add the other ingredients, 
 except dextrose, which is added to the cleared and filtered 
 product. No neutralization is necessary. Tube in regular 
 way. For tube cultures this medium is modified by using 
 agar 5 gm. and gelatin 80 gm. in place of the quantities given 
 above. A careful titration is made and the reaction adjusted 
 to 1.5 per cent, acid by adding HCl. After filtration, dex- 
 trose is added, then tubed and sterilized. 
 
 Hesse's Medium for Tjrphoid 
 
 Agar Sgm. 
 
 Peptone 10 gm. 
 
 Extract of beef 5 " 
 
 Sodium chlorid 8.5 " 
 
 Water 1000 c.c. 
 
 Digest agar in 500 c.c. water, add the other ingredients 
 dissolved in water. Mix and filter. Adjust reaction to i 
 per cent, acid, tube, and sterilize in autoclave. 
 
 Bile Salt Agar (MacConkey's) 
 
 Sodium taur-ocholate .- 0.5 part 
 
 Peptone 1.5 parts 
 
 Lactose 3.5 *' 
 
 Agar 1.5 " 
 
 Water q. s. loo.o " 
 
 Agar and peptone dissolved first. Lactose and bile salt 
 added before tubing. Sterilize on three days intermittently. 
 
76 ESSENTIALS OF BACTERIOLOGY 
 
 (A) Conradi-Drigalski Medium 
 
 Fresh meat 1500 gm. 
 
 Water 2000 c.c. 
 
 Mix and allow to stand twelve hours. Strain, boil one 
 hour, and add — 
 
 Peptone 20 gm. 
 
 Nutrose 20 " 
 
 NaCl 10 " 
 
 Boil one hour, filter, then add — 
 Agar 60 gm. 
 
 Boil one hour in autoclave or until agar is dissolved. 
 Render weakly alkaline to litmus, filter, and boil one-half 
 hour. 
 
 (B) 
 
 Litmus solution (Kahlbaum) 300 c.c. 
 
 Lactose 30 gm. 
 
 Boil fifteen minutes. Mix with solution A, and make 
 slightly alkaline with soda solution. Then add 4 c.c. 10 per 
 cent, soda carbonate solution (hot sterile) and 20 c.c. of 
 sterile i : 1000 crystal violet solution (Hochst B). 
 
 Lactose-bile {Jackson). — Sterilized undiluted ox-gall, 
 98 parts; or dry bile, 10 per cent, solution; peptone, i part; 
 lactose, I part. M. Filled into fermentation tubes, 40 c.c. 
 each, sterilized fractional method. 
 
 Blood-agar. — Human or other blood is obtained direct 
 from the body under strict aseptic conditions, and a few 
 drops smeared over the surface of agar in tubes or plates. 
 These are then placed in the incubator for a few days, and the 
 contaminated ones are rejected. This medium is used for 
 influenza bacilli and gonococci. 
 
 Eisner's Medium (for Typhoid) (Potassitmi lodid — 
 Potato-gelatin). — Five hundred grams of peeled and 
 washed potatoes are mashed and pressed through a fine 
 cloth. The juice is allowed to settle, is filtered, and after 
 one hour's cooking has added to it 10 per cent, gelatin; then 
 
NUTRIENT CULTURE-MEDIA 77 
 
 2jE^ c.c. tV normal sodium hydroxid solution, and finally i per 
 cent, potassium iodid. 
 
 Endo Medium (Fuchsin-Lactose-Agar). — To looo c.c. 
 agar add lactose, lo grams; fuchsin (saturated alcoholic 
 solution), 2 c.c; solution sodium sulphite (lo per cent.), 25 
 c.c; sterilize in steam, and make acid, o.i per cent. 
 
 Peptone Water (Modified Dunham) {Mother Solution): 
 
 Dry peptone (Witte) 100 parts 
 
 Sodium chlorid 100 
 
 Potassium nitrate i part 
 
 Sodium carbonate i 
 
 Distilled water (95) q. s. ad 1000 parts — ^M. 
 
 When wanted for use, dilute ten times with water. 
 
 Dunham's rosalic acid solution consists of the following: 
 
 Peptone solution (Dunham) 100 c.c. 
 
 2 per cent, solution rosalic acid 0.5 gm. 
 
 Alcohol (80 per cent.) 100 c.c. — M. 
 
 To detect acids and alkalis. 
 
 Dieudonne*s Mediimi: 
 
 A. Normal solution potassium hydrate, defibrinated ox- 
 blood, equal parts. Mix, sterilize in autoclave. 
 
 B. Nutrient agar (neutral). Mix 3 parts A wdth 7 parts 
 B, and pour into Petri dishes; allow to stand forty-eight 
 hours at room temperature before using. 
 
 Milk Culture-medium. — The milk used should be fresh 
 and should be placed on ice for eight to ten hours to allow the 
 cream to rise; the skimmed milk is siphoned off into flasks 
 or tubes and sterilized for three successive days. Litmus is 
 often added, or sterile i per cent, azolitmin solution. 
 
 Fresh Egg Cultures (After Hueppe). — The eggs in the 
 shell are carefully cleaned, washed with sublimate, and dried 
 with cotton. 
 
 The inoculation occurs through a very fine opening made 
 in the shell with a hot platinum needle; after inoculation, the 
 opening is covered with a piece of sterilized paper and collo- 
 dion. 
 
78 ESSENTIALS OF BACTERIOLOGY 
 
 Boiled Eggs.— Eggs boiled, shell removed over small por- 
 tion, and the coagulated albumen stroked with the material. 
 
 Guinea-pig Bouillon. — The flesh of guinea-pigs, as well 
 as that of other experiment animals, is used instead of beef 
 in the preparation of bouillon, for the growth of special germs. 
 
 The extracts of different organs have been added to the 
 various media for experimentation. 
 
 Wertheim's Medium for Gonococcus: 
 
 Nutrient agar 2 parts 
 
 Human blood-serum or hydrocele 
 
 fluid I part 
 
 Melt agar and cool to 45° C; then add serum. Tube on 
 slant or pour in Petri plate. Glycerin or glucose can be added 
 to enrich. 
 
 Solution Dried Blood Albumin (King) : 
 
 Blood albumin (commercial) 15 parts 
 
 Glucose bouillon 85 '' 
 
 Dissolve, tube, inspissate, and sterilize as for blood-serum. 
 
 CHAPTER XI 
 
 INOCULATION OF CULTURE-MEDIA 
 
 Glass Slide Cultures. — Formerly the gelatin was poured 
 on little glass slides, such as are used for microscopic purposes, 
 and after it had become hard, inoculated in separate spots as 
 with potatoes. 
 
 ' Test-tube Cultures.— The gelatin, agar, or blood-serum 
 having solidified in an oblique position is smeared on the 
 surface with the material, and the growth occurs along the 
 smear, or the medium is punctured with a stab of the plati- 
 num rod containing the material, and the growth follows 
 the line of thrust. The former is called a stroke or smear 
 culture, the latter a stah or thrust culture. 
 
INOCULATION OF CULTURE-MEDIA ' 79 
 
 Streaked Surface Plating. — The surface of the medium, 
 hardened in a Petri dish, is scratched by a needle containing 
 the inoculating material, three or more streaks being made 
 without obtaining fresh material, so that the growth along 
 the streak or scratches will represent varying amounts of 
 the substance to be tested. In removing the cotton plugs 
 from the sterile tubes to carry out the inoculation the plugs 
 should remain between the fingers in such a way that the 
 part which comes in contact with the mouth of the tube will 
 not touch anything (Fig. 23). 
 
 It is well to pass the mouth of the tube and the cotton 
 plugs through a flame, scorching the latter before reinserting; 
 
 Fig. 23. — Manner of holding plugs. 
 
 Sterilizing Needle. — Sterilize needles by passing through 
 the flame before and after each inoculation; also sterilize the 
 glass part, as it is liable to become infected. 
 
 After the needle has been withdrawn, the plugs are rein- 
 serted and the tubes labeled with the kind and date of culture. 
 
 Plate Cultures. — Several tubes of the culture-medium 
 are made liquid by heating in water-bath, and then inocu- 
 lated with the material as follows. A looped platinum needle 
 is dipped into the material and then shaken in the tube of 
 liquid media (gelatin, agar, etc.). 
 
 This first tube is called original. From this three drops 
 (taken with the looped platinum rod, Fig. ii, p. 45) are 
 placed in a second tube, the rod being shaken somewhat in the 
 
8o 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 gelatin or agar; this is labeled first dilution (a colored pencil 
 is useful for such markings). From the first dilution three 
 drops are taken into a third tube, which becomes the second 
 dilution. 
 
 The plugs of cotton must be replaced after each inocula- 
 tion, and while being held must be carefully protected from 
 contamination. 
 
 Glass Plating. — The larger the surface over which the 
 nutrient medium is spread, the more isolated will the colonies 
 be; window glass cut in rectangular plates 6x4 inches in 
 size was formerly used, but now Petri dishes consisting of 
 2 circular glass or porcelain dishes, one fitting over the other 
 as a cover, are universally employed (Fig. 24). They are 
 sterilized, the softened and inoculated agar or gelatin is 
 poured from the test-tube into the dish with as much speed 
 
 Fig. 24. — Petri dish for making plate cultures. 
 
 as possible, and the lid replaced, avoiding contamination 
 from the air and surroundings. They are labeled or marked 
 with pencil, and placed in the incubator or kept at room 
 temperature for further development. 
 
 This method is very useful for transportation, and does 
 away with the cooling apparatus and moist chamber for- 
 merly employed; the saucers can be viewed under micro- 
 scope similar to the glass plates, and have entirely super- 
 seded them. 
 
 Esmarch's Tubes or Rolled Cultures. — This method, 
 especially used in the culture of anaerobic germs, consists in 
 spreading the inoculated gelatin upon the inner w^alls of the 
 test-tube in which it is contained and allowing it to congeal. 
 
INOCULATION OF CULTURE-MEDIA 
 
 The colonies then develop upon the sides of the tube without 
 the aid of other apparatus. The method is useful whenever a 
 very quick and easy way is required. The rolling of the tube 
 is done under ice-water or running water from the faucet. 
 The tube is held a little slanting, so as to avoid getting too 
 much gelatin around the cotton plug. 
 
 The tubes can be placed directly under the microscope for 
 further examination of the colonies. 
 
 Animals as Culture-media. — It is 
 almost impossible to separate certain 
 organisms, such as the tubercle bacil- 
 lus and pneumococcus, from mixed 
 cultures by ordinary plate methods, 
 and the plan of producing the disease 
 in animals by inoculation, and then 
 obtaining the organism in pure cul- 
 ture, has to be employed. 
 
 Pure Cultures by Boiling. — 
 Spored organisms may be separated 
 from others by boiling the mixture for 
 a few minutes, when all the non-spored 
 forms will perish, and only the spores 
 remain to germinate subsequently. 
 
 Fermentation Tube. — For show- 
 ing the presence of gas or fermenta- 
 tion the Smith tube (Fig. 25) or some 
 of its modifications must be used. 
 The closed end and part of the bulb 
 are filled with the glucose or dextrose 
 
 bouillon and sterilized at low temperatures for three succes- 
 sive days, then inoculated and placed in the incubator. Gas 
 forms gradually, displacing the fluid in the closed end. 
 
 -Smith's fer- 
 mentation tube. 
 
82 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 CHAPTER XII 
 
 CULTIVATION OF ANAEROBIC BACTERIA 
 
 Special methods are necessary for the culture of the ana- 
 erobic variety of bacteria in order to procure a space devoid 
 of oxygen. 
 
 Liborius's High Cultures. — The tube is filled about 
 three-quarters full with gelatin, which is then steamed in a 
 water-bath and allowed to cool to 40° C, when it is inoculated 
 
 ^ 
 
 Fig. 26. — Liborius's method. 
 
 Fig. 27. — Hesse's method of making 
 anaerobic cultures (McFarland). 
 
 by means of a long platinum rod with small loop, the move- 
 ment being a rotary vertical one, and the rod going to the 
 bottom of the tube. 
 
 The gelatin is next quickly solidified under ice; very little 
 air is present. The anaerobic germs will grow from the 
 
CULTIVATION OF ANAEROBIC BACTERIA 
 
 83 
 
 bottom upward, and any aerobins present will develop first 
 on top, this method being one of isolation. 
 
 From the anaerobic germ grown in the lower part a stab 
 culture is made into another tube containing three-quarters 
 gelatin, the material being obtained by breaking test-tube 
 with the culture. (See Fig. 26.) 
 
 Hesse's Method. — A stab-culture having been made with 
 
 Fig. 28. — Frankel's method of Fig, 29. — Buchner's method of 
 making anaerobic cultures (McFar- making anaerobic cultures (Mc- 
 land). Farland). 
 
 anaerobic germs, gelatin in a semisolid condition is poured 
 into the tube until it is full, thus displacing the air (Fig. 27). 
 Esmarch's Method. — Having inoculated a tube, the gela- 
 tin is rolled out on the walls of the tube, a "roll culture," 
 and the rest of the interior is filled with gelatin, the tube 
 bei^g held in ice-water. The colonies develop upon the sides 
 of the tube and can be examined microscopically. 
 
84 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Gases like Hydrogen to Replace the Oxygen. — Several 
 arrangements for passing a stream of hydrogen through the 
 culture : 
 
 Frankel puts in the test-tube a rubber cork containing two 
 glass tubes, one reaching to the bot- 
 tom and connected with a hydrogen 
 apparatus, the other very short, 
 both bent at right angles. When 
 the hydrogen has passed through 
 from ten to thirty minutes, the 
 short tube is annealed and then the 
 one in connection with the hy- 
 drogen bottle, and the gelatin 
 rolled out upon the walls of the 
 tube (Fig. 28). 
 
 Use of Aerobic Bacteria to 
 Remove the Oxygen. — Roux in- 
 oculates an agar tube through a 
 needle-thrust, after which semi- 
 solid gelatin is poured in on top. 
 When the gelatin has solidified, the 
 surface is inoculated wdth a small 
 quantity of Bacillus subtilis or 
 some other aerobic germ. The 
 subtilis does not allow the oxygen 
 to pass by, appropriating it to 
 itself. 
 
 Buchner's Method. — The test- 
 tube containing the culture is 
 placed within a larger tube, the 
 lower part of w^hich contains an 
 alkaline solution of pyrogallic acid. 
 The tube is then closed with a rub- 
 ber stopper (Fig. 29). 
 Botkin's Method. — Petri dishes, uncovered, are placed 
 on a rack under a large bell-jar, into which hydrogen gas is 
 conducted. Alkaline pyrogallic acid is placed in the upper 
 
 Fig. 30. — Wright's 
 method for the cultivation 
 of anaerobes. 
 
CULTIVATION OF ANAEROBIC BACTERIA 
 
 8s 
 
 and lower dishes to absorb what oxygen remains. The Novy 
 jar (Fig. 31) is used instead of a bell- jar, and sealed after 
 the oxygen is displaced by hydrogen gas. 
 
 Wright's Method.— Applicable to both fluid and solid 
 media. After the test-tube is inoculated the plug, which 
 must be of absorbent cotton, is cut off flush with the ex- 
 tremity of the tube and pushed inward for a distance of i cm. 
 It is then impregnated with i c.c. of a watery solution of 
 pyrogallic acid and i c.c. of 5 per cent, sodium hydroxid 
 
 Fig. 31. — Novy's jars for anaerobic cultures. 
 
 solution. A tightly fitting rubber stopper is inserted, and 
 the tube is then ready for incubation (Fig. 30). 
 
 Park's Method. — An Erlenmeyer flask containing the 
 medium to be used is boiled in a water-bath from ten to 
 fifteen minutes to drive off dissolved oxygen, quickly cooled, 
 and inoculated. Hot melted paraffin is then poured into the 
 flask, which forms a layer over the medium, and on congeal- 
 ing, provides an air-tight seal which does not adhere to the 
 glass so closely as to prevent the escape of any gases formed 
 by the bacterial growth. 
 
 Requirements for a Small Laboratory 
 Incubator, with thermostat and thermometers. 
 Hot-air oven. 
 
86 ESSENTIALS OF BACTERIOLOGY 
 
 Arnold steam sterilizer. 
 
 Autoclave. 
 
 Bunsen burners. 
 
 Erlenmeyer or liter glass flasks, yi dozen. 
 
 Test-tubes, loo. 
 
 One I GOO c.c. measuring glass. 
 
 One I GO c.c. measuring glass. 
 
 One 5 c.c. pipet. 
 
 One I c.c. pipet. 
 
 One accurate buret. 
 
 One-half dozen 20 c.c. porcelain capsules. 
 
 Glass stirring rods. 
 
 Normal soda solution. 
 
 Hydrochloric acid. 
 
 Lactose, dextrose, glucose, and phenolphthalein. 
 
 A selection of dry stains, especially fuchsin, methylene- 
 blue, and eosin. 
 
 Gram's solution. 
 
 Phenol. 
 
 Alcohol, methyl alcohol. 
 
 Cover-glasses, slides. 
 
 Canada balsam, cedar-oil, xylol. 
 
 A small microtome and embedding material. 
 
 Cotton- wool for plugs. 
 
 Twenty-five or more Petri dishes. 
 
 Four platinum needles in glass handles. 
 
 One-half dozen fermentation tubes. 
 
 One-half dozen tubes for potato culture. 
 
 One Novy jar. 
 
 One animal holder. 
 
 Three wire boxes for holding tubes. 
 
 Test-tube rack. 
 
 The materials must include what is needed for making 
 culture-media: agar, gelatin, peptone, beef-extract, chemic- 
 ally pure salt. 
 
 And to this there will be added from time to time such 
 other apparatus and material as occasion demands. 
 
THE GROWTH AND APPEARANCES OF COLONIES 87 
 
 CHAPTER XIII 
 
 THE GROWTH AND APPEARANCES OF COLONIES 
 
 Macroscopic. — Depending greatly upon the temperature, 
 which should be about 65° F. (20° C.) for gelatin, and 40° C. 
 for agar, the colonies ordinarily develop so as to be visible to 
 the naked eye in two to four days. Some require ten to four- 
 teen days, and others grow rapidly, covering the third dilu- 
 tion in thirty-six hours. The plate should be looked at each 
 day. 
 
 The colonies present various appearances from that of a 
 
 Fig. 32. — Staphylococcus pyogenes aureus: colony two days old, seen 
 upon an agar-agar plate (X40) (Heim). 
 
 small dot, like a fly-speck, to that resembling a small leaf. 
 Some are elevated, some depressed, and some, like cholera, 
 cup-shaped — umbilicated. 
 
 Then they are variously pigmented. Some liquefy gelatin 
 speedily, others not at all. The appearances of a few are 
 so characteristic as to be recognized at a glance. Some 
 produce gas-bubbles. 
 
88 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Microscopic. — Use a low-power lens, with the Abbe 
 nearly shut out — that is the narrowest blender. The stage of 
 the microscope should be of such size as to carry a Petri 
 saucer easily upon it. 
 
 The second dilution or third plate is usually made use of — 
 that one containing the colonies sufficiently isolated. 
 
 These isolated ones should be sought for, and their appear- 
 ance well noticed. 
 
 There may be two or three forms from the same germ, the 
 difference due to the greater or less amount of oxygen that 
 
 Fig. 33- — Microscopic appear- 
 ances of colonies. 
 
 Fig, 34. — Klatsch preparations. 
 
 they have received, or the greater or less amount of space 
 that they have had to develop in. 
 
 The microscopic picture varies greatly; now it is like the 
 gnarled roots of a tree, and now like bits of frosted glass; 
 some bacteria have quite characteristic colonies (Fig. 32). 
 
 Impression or "Klatsch*' Preparations.— In order 
 more thoroughly to study a certain colony and to make a 
 permanent specimen of the same, we press a clean cover-glass 
 upon the particular colony, and it adheres to the glass. It 
 can then be stained or examined. The Germans give the 
 name of "Klatsch" to such preparations. 
 
 Fishing. — To obtain and examine the individual members 
 
THE GROWTH AND APPEARANCES OF COLONIES 
 
 89 
 
 of a particular colony the process of fishing, as it is called, is 
 resorted to. 
 
 The colony having been placed under the field of the micro- 
 
 Fig. 35. — Types of growth in stab-cultures: A, Non-liquefying: i, 
 Filiform (Bacillus coli); 2, beaded (Streptococcus pyogenes); 3, echinate 
 (Bacterium acidi lactici); 4, villous (Bacterium murisepticum) ; 5, arbor- 
 escent (Bacillus mycoides). B, Liquefying: 6, Crateriform (Bacillus 
 vulgare, twenty-four hours); 7, napiform (Bacillus subtilis, forty-eight 
 hours); 8, infundibuliform (Bacillus prodigiosus) ; 9, saccate (Micro- 
 sporon Finkleri); 10, stratiform (Psorospermum fluorescens) (Frost). 
 
 scope, a long platinum needle, the point slightly bent, is 
 passed between the lens and the plate so as to be visible 
 through the microscope, then turned downward until the 
 colony is seen to be disturbed, and the needle is dipped into 
 
90 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 the colony. This procedure must be carefully done, lest a 
 different colony be disturbed than the one looked at, and an 
 unknown or unwanted germ obtained. 
 
 After the needle has entered the particular colony, it is 
 withdrawn, and the material thus obtained is further exam- 
 ined by staining and animal experimentation. The bacteria 
 
 
 L 
 
 / -/- \ 
 
 Fig. 36. — ^Types of stroke cultures: i, Filiform (Bacillus coli); 2, 
 echinulate (Bacterium acidi lactici); 3, beaded (Streptococcus pyogenes); 
 4, effuse (Bacillus vulgaris); 5, arborescent (Bacillus mycoides) (Frost). 
 
 are further cultivated by inoculating fresh gelatin or agar, 
 making stab- and stroke cultures. 
 
 It is necessary to transfer the bacteria to fresh media about 
 every six weeks, as the products of growth and decay given 
 off by the organisms destroy them. Stroke and stab test- 
 tube cultures are more characteristic than plate cultures, as 
 the types in Figs. 35 and 36 show. 
 
ANIMAL INOCULATION 91 
 
 CHAPTER XIV 
 
 ANIMAL INOCULATION 
 
 Used: (i) For obtaining pure cultures; (2) to determine 
 virulence; (3) to regain virulence of an organism that has 
 become exhausted in artificial media; (4) to furnish a suit- 
 able culture-medium for bacteria that have so far failed to 
 grow on other media. 
 
 The smaller rodents and birds are the ones usually employed 
 for inoculation, as rabbits, guinea-pigs, rats, mice, pigeons, 
 and chickens. These are preferred, because easily affected 
 by the various bacteria, readily obtained, and not expensive. 
 Monkeys have been used in recent years in connection with 
 syphihs and meningitis. 
 
 The white mouse is very prolific and easily kept, and is 
 therefore a favorite animal for experiment. It lives well 
 upon a little moistened bread. A small box, perforated with 
 holes, is filled partly with sawdust, and in this ten to twelve 
 mice can be kept. When the female becomes pregnant, she 
 should be removed to a glass jar until the young have opened 
 their eyes, because the males, which have not been raised 
 together, are apt to attack each other. 
 
 Guinea-pigs. — When guinea-pigs have plenty of light and 
 air, they multiply rapidly. Therefore it is best to have them 
 in some large stall or inclosure. They can be fed upon all 
 sorts of vegetables and grasses, and require but little atten- 
 tion. 
 
 Methods of Inoculation. — /. Inhalation. — Imitating the 
 natural infection, either by loading an atmosphere with the 
 germs in question or by administering them with a spray. 
 
 //. Through skin or mucous membrane. 
 
 III. With the food. 
 
 Method of Cutaneous Inoculation. — The ear of a mouse 
 is best suited for this procedure. A small abrasion is made with 
 the point of a lancet or needle, which has been dipped in the 
 virus or material to be inoculated. The animal is then sepa- 
 
92 ESSENTIALS OF BACTERIOLOGY 
 
 rated from the rest and placed in a glass jar, which is partly 
 filled with sawdust and covered with a piece of wire gauze. 
 
 Subcutaneous. — The root of the tail of a mouse is used for 
 this purpose. The hair around the root of the tail is clipped 
 off, and with a pair of scissors a very small pocket is made in 
 the subcutaneous connective tissue, not wounding the animal 
 any more than is absolutely necessary, avoiding much blood. 
 The inoculating material is placed upon a platinum needle 
 and introduced into the pocket; solid bodies, with a forceps. 
 
 To hold the mouse still while the operation is going on a 
 little cone made of m^etal is used. The mouse just fits in 
 here. There is a slit along the top in which the tail can be 
 fastened, and thus the animal is secure and immobile. 
 
 Variously designed animal-holders are on the market and 
 used in laboratories. 
 
 Intravenous Injections. — Rabbits are very easily in- 
 jected through the veins. Mice are too small. 
 
 The ear of the rabbit is usually taken. It is first washed 
 with I : 2000 bichlorid, w^hich not only disinfects, but also 
 makes the vessels appear more distinct. The base of the ear 
 is compressed to sw^ell the veins. Then a hypodermic 
 syringe, which can be easily sterilized, is filled with the de- 
 sired amount of virus, which is slowly injected into any one 
 of the more prominent veins present (Fig. 37). 
 
 Intraperitoneal Injection. — This is used with guinea- 
 pigs chiefly. The abdominal wall is pinched up through its 
 entire thickness, and the needle of the syringe thrust directly 
 through, so that it appears on the other side, then the fold 
 let go, the needle withdrawn just far enough so as to be within 
 the cavity. 
 
 Inoculation in the Eye. — The anterior chamber and the 
 cornea are the two places used. The rabbit is fixed upon a 
 board, the eyefids held apart and head held still by an assist- 
 ant. A few drops of cocain having first been introduced in 
 the eye, a small cut is made in the cornea. The material is 
 passed through the opening with a small forceps, and with a 
 few strokes of a spoon it is pushed in the anterior chamber. 
 
ANIMAL INOCULATION 93 
 
 For the cornea a few scratches made in the corneal tissue 
 will suffice ; the material is then gently rubbed in. 
 
 Inoculation of the Cerebral Membranes. — The skin 
 and aponeurosis cut through where the skull is the thinnest. 
 Then the bone carefully trephined, and the dura exposed. In 
 rabies inoculation, the syringe containing the hydrophobic 
 virus pierces the dura and arachnoid, and the virus is dis- 
 charged beneath the latter. 
 
 Fig. 37. — Method of making an intravenous injection into a rabbit. 
 Observe that the needle enters the posterior vein from the hairy sur- 
 face. 
 
 Intratracheal. — The bacteria can be introduced directly 
 into the trachea, thus coming in contact with the lungs. 
 
 Intraduodenal. — Cholera germs are injected into the in- 
 testines after they have been exposed by carefully opening 
 the abdomen. This is done in order to avoid the action of 
 the gastric juice. 
 
 Celloidin sacs of small size are sometimes used to intro- 
 
94 ESSENTIALS OP BACTERIOLOGY 
 
 duce living cultures of bacteria into the bodies of animals 
 without their coming into direct contact with the tissues. 
 
 Obtaining Material from Infected Animals. — The ani- 
 mal should be skinned, or the hairs plucked out, before it is 
 washed — at least the portion where the incision is to be made. 
 Then the entire body is washed in sublimate. Two sets of 
 instruments are required — one for coarser and one for finer 
 work: the one sterilized in the flame; the other, to prevent 
 being damaged, heated in a hot-air oven. 
 
 The animal, the mouse, for example, is stretched upon a 
 board, a nail or pin through each leg, and the head fixed with 
 a pin through the nose. The skin is dissected away from the 
 belly without exposing the intestines. Then the ribs, being 
 laid bare, the sternum is lifted up, and the pericardium ex- 
 posed. A platinum needle dipped into the heart after the 
 pericardium has been slit will give sufficient material for 
 starting a culture. If the other organs are to be examined, 
 further dissection is made. If the intestines are first to be 
 looked at, they should be laid bare first. 
 
 In this manner material is obtained and the results of 
 inoculation noted. 
 
 Frequent sterilization of the instruments is desirable. 
 
 Koch's Rules in Regard to Bacterial Cause of Disease. 
 — Before a microbe can be said to be the cause of a disease, it 
 must — 
 
 First, be found in the tissue or secretions of the animal suf- 
 fering from, or dead with, the disease. 
 
 Second, it must be cultivated outside of the body on ar- 
 tificial media. 
 
 Third, a culture so obtained must produce the disease in 
 question when it is introduced into the body of a healthy 
 animal. 
 
 Fourth, the same germ must then again be found in the 
 animal so inoculated. 
 
BACTERINS (VACCINES) 9$ 
 
 CHAPTER XV 
 BACTERINS (VACCINES) 
 
 Bacterins are sterilized suspensions of bacteria in normal 
 saline solution. The term vaccines or bacterial vaccines is 
 frequently but erroneously used in place of bacterins, as the 
 word vaccine relates to a cow or calf. Bacterins are used in 
 the treatment of locaHzed infections, and especially those of 
 a chronic nature, and have been employed extensively to es- 
 tablish immunity against infection. The best example of 
 this is the immunization of armies and inmates of institu- 
 tions against typhoid fever. 
 
 Preparation. — The organism is grown on the surface of 
 the most appropriate medium, usually agar-agar, until an 
 abundant growth is present. This ordinarily requires 
 twenty-four hours. The growth is then washed from the 
 medium with sterile normal saline solution, and collected in 
 a small sterilized flask or bottle containing glass beads and 
 shaken to break up clumps. A sterilized glass bulb, drawn 
 to a point (a test-tube drawn out answers as well), is filled 
 with the resulting emulsion, the end sealed in a flame, and the 
 bulb immersed in a water-bath at 60° C. for one hour. The 
 neck of the bulb is then broken, and a few drops of the emul- 
 sion sown on culture-media to determine the presence or ab- 
 sence of living organisms. 
 
 Standardization. — The number of bacteria in a cubic cen- 
 timeter of the mixture is determined as follows: a portion 
 of the emulsion is reserved unheated, and at once mixed 
 with an equal volume of blood by aspirating into a capillary 
 tube any quantity, usually a column 2.5 cm. long, of the 
 emulsion, followed by an equal volume of blood. The blood 
 and emulsion are then mixed on a glass slide and thin smears 
 are made. After air drying, the films are fixed with satur- 
 ated solution of bichlorid of mercury and stained with car- 
 bolthionin. 
 
96 ESSENTIALS OF BACTERIOLOGY 
 
 Counting. — Two crossed hairs are placed on the dia- 
 phragm in the eye-piece of the microscope and the slide 
 examined under the oil-immersion lens. The number of cor- 
 puscles and bacteria in a number of fields are counted until 
 at least 200 red corpuscles have been enumerated. As the 
 number of corpuscles per cubic centimeter is 5,cxdo,ooo,ooo 
 by simple proportion, the number of bacteria per cubic centi- 
 meter can be determined. For example, 200 red corpuscles 
 and 150 bacteria are counted in the same fields. Then — 
 
 200 corpuscles : 150 bacteria : : 5,000,000,000 : x x = 3, 750,000,0000 
 (Number of corpuscles is to number of bacteria as the total number 
 of corpuscles in a cubic centimeter is to the quantity to be determined.) 
 
 Any number of bacteria per cubic centimeter can then be 
 obtained by simple dilution with sterile normal saline solu- 
 tion. When the final dilution is made, 0.2 per cent, of tri- 
 kresol is added as a preservative. 
 
PART II 
 SPECIAL BACTERIOLOGY 
 
 CHAPTER XVI 
 SOME COMMON BACTERIA SLIGHTLY PATHOGENIC 
 
 Bacterium Prodigiosum (Ehrenberg). — This bacillus, 
 formerly called micrococcus, is very common, and was one of 
 the first noticed, because of the brilliant red pigment it 
 forms on cooked vegetables and starchy substances. "The 
 bleeding host" miracles are said to have been due to it. 
 
 Morphology. — Short rods, often in filaments, resembling 
 cocci, ends slightly pointed, i jli in size ; spores absent. 
 
 Facultative anaerobic, that is, it can grow without air; but 
 the pigment requires oxygen for its development. 
 
 Flagella and motion present in young bouillon cultures. 
 Absent in older and those grown on potato. 
 
 Stain easily with ordinary watery stains, but not with 
 Gram. 
 
 Cultural Features. — Agar stroke: Growth limited to stroke; 
 filiform, varying from a light pink to dark purple in color, 
 due to pigment (prodigiosin) formed by the growing colonies. 
 Odor of trimethylamin present. Media colored brow n under- 
 neath growth. 
 
 On potato, growth of pigment appears best. At first rose 
 red, then in a few days dark purple, with a glistening, green- 
 gold luster, resembling the dry fuchsin dye. Odor more 
 pronounced. 
 
 Gelatin Stab. — In six hours liquefaction begins on surface, 
 and spreading downward; funnel shape; the liquid portion 
 7 97 
 
98 ESSENTIALS OF BACTERIOLOGY 
 
 containing small flakes of red pigment which settle at the 
 bottom. Milk coagulated in twenty-four hours. - 
 
 Agar Colonies. — Small red points in thirty-six hours, irregu- 
 lar in outline. Granular in structure. 
 
 Gelatin Colonies. — On the surface, round, granular, smooth 
 edges which soon liquefy a,nd have depression in center. The 
 edges then become irregular. 
 
 Biologic Features. — The characteristic red pigment is in- 
 soluble in water, slightly soluble in alcohol and ether; alka- 
 lies turn it orange, acids, violet red. Light fades it. Gases 
 of methylamin and ammonia are produced. Gas and acid 
 
 produced in sugar solutions. 
 Indol feeble. 
 
 Temperature, 22°-25° C.; higher 
 temperatures interfere with pig- 
 ment. 
 
 Pathogenic for small animals. 
 When injected intraperitoneally, 
 1-2 c.c. has proved fatal; causes 
 intoxication. Proteids of the cul- 
 tures poisonous. 
 Fig. 38.— Colony of Bacillus Cancer Remedy. — Used in 
 mesentericus vulgatus. Coley's treatment mixed with 
 
 cultures of streptococci. 
 Bacillus Mesentericus Vulgatus {Bacillus Vulgatus; 
 Potato Bacillus of Flilgge) (Fig. 38). 
 
 Origin. — Surface of the soil, on potatoes, and in milk. 
 Form. — Small thick rods with rounded ends, often in pairs. 
 Very motile; produces abundant spores. 
 Cultures. — Rapid growth; stain with Gram. 
 Agar Colonies. — Round, with transparent center at first, 
 then becoming opaque. The border is ciliated; little pro- 
 jections evenly arranged. 
 
 Potato. — A white covering at first, which then changes to 
 a rough brown skin; the skin can be detached in long 
 threads. 
 
 Temperature. — Spores at ordinary temperature. 
 
SOME COMMON BACTERIA SLIGHTLY PATHOGENIC 
 
 99 
 
 Spores. — Are very resistant; are colored in the manner 
 described in first part of the book for spores in general. 
 
 Bacillus Megaterium (de Bary) (Fig. 39).— Origw.— 
 Found on rotten cabbage and garden-soil. 
 
 Form. — Large rods, four times as long as they are broad, 
 2.5 ju. Thick, rounded ends. Chains with ten or more mem- 
 bers often formed; granular cell contents. 
 
 Abundant spore formation; very slow movement. 
 
 Growth. — Strongly aerobic; grows quickly and best at a 
 temperature of 20° C. 
 
 Fig. 39. — Bacillus megaterium, with spores. 
 
 Plate Colonies. — Small, round, yellow points in the depth of 
 the gelatin. Under microscope, irregular masses like B, 
 subtilis. ' • \' ' 
 
 Stab-culture. — Funnel-shaped from above downwa]*4^ 
 
 Potato. — Thick growth with abundance of epor^ 4ike -.©, 
 subtilis. ' -' ' , >'*^ ' 
 
 Bacillus Ramosus . — Synonyms. ^Bacillus ^ ^[tnyeotdes 
 (Fliigge); Wurzel or root bacillus. ^ ^' '.- '■ 
 
 Origin. — In the upper layers of gardei^ or fafni grounds and 
 in water. "^^.'^ \'' 
 
 Form. — Short rods, with rourrdM ends, sbout three times 
 as long as they are thick; often in- ibn^ 'threads and chains. 
 
100 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 ImmoHle. 
 Stain. — Gram. 
 
 Agar Stroke. — Gray soft mass, gnarled and twisted; feath- 
 ery extensions spreading over entire surface. 
 
 Gelatin Stab. — Arborescent and plumose-parallel projections 
 on either side of the stab; a thick skin on surface with slow 
 liquefaction (Fig. 40). 
 
 Colonies. — Twisted threads, like a bundle of hair; opaque 
 center; the threads or branches divide endlessly, forming coils. 
 Growth. — -At ordinary temperature, 
 with plentiful supply of air. 
 
 Staining. — Spores stain readily with 
 the ordinary spore stain. 
 
 Bacterium Zopfii (Kurth) (1883).— 
 Origin. — Intestines of a fowl. 
 
 Form. — Short thick rods forming long 
 threads coiled up, which f.nally break up 
 into spores, which were cnce thought to 
 be micrococci. 
 
 Properties.' — Very motile; does not 
 
 dissolve or liquefy gelatin. Produces 
 
 putrefaction in albuminous m.edia, with 
 
 gas formation. 
 
 Growth. — In thirty hours abundant growth ; aerobic; grows 
 
 best at 20° C. 
 
 Agar Plates. — Small white points which fcrm the center of a 
 very, fine netting. With high power this netting is found 
 composed of bacilli in coils, like braids of hair. 
 T YjXfiQ^epX impress or "Klatsch" preparations are obtained 
 ■froEi th'es/i cejonies. 
 '' Suiiping s-r-Ordinsiry dyes and Gram. 
 
 Bapillu^ SuHiH^ (Hay Bacillus) (Ehrenberg). — Origin. 
 — Hay kifusionsV 'found also in air, water, soil, feces, and 
 putrefying Jiciui4s. jV'S'ry common, often contaminates cul- 
 tures. '''-/ ' ' '\''y/ ' 
 
 Form. — Short, ^thiek rods;' jdiree times as long as broad; 
 slight roundness of ends^,, seldom found singly; usually in 
 
 Fig. 40. — Bacillus 
 mycoides (Frost). 
 
SOME COMMON BACTERIA SLIGHTLY PATHOGENIC lOI 
 
 long threads. Flagella are found on the ends. Spores of 
 oval shape, strongly shining, very resistant. 
 
 Very motile; Gram stain. , 
 
 Growth. — Rapid; strongly aerobic. 
 
 Plate. — Round, gray colonies with depressed white center. 
 Under microscope the center yellow; the periphery like a 
 wreath, with tiny little rays projecting; very characteristic. 
 
 Agar Stroke. — Soft, round, smooth edges; gray. 
 
 Gelatin Stab. — Gray on surface, sinks in thirty-six hours, 
 shallow crater, in which small white particles are floating; 
 as gelatin softens a skin forms on surface. 
 
 Potato. — Thick, dirty-white growth, spreading over sur- 
 face; dull, raised edges, wavy. 
 
 Properties like B. vulgatus. 
 
 Pathogenic. — Has been found present in eyeball suppura- 
 tions, especially panophthalmitis. Injected in guinea-pigs it 
 causes toxemia and death. Has been found in acute conjunc- 
 tivitis, and may at times produce it. 
 
 Staining. — Rods, ordinary stain; spores, spore stain. 
 
 It is easily obtained by covering finely cut hay with dis- 
 tilled water, and boiling a quarter of an hour. Set aside 
 forty-eight hours. A thick scum will show itself on the sur- 
 face, composed of the subtilis bacilli, whose spores alone have 
 survived the heat. 
 
 Was formerly considered a non- virulent form of B. anthrax. 
 
 Boas-Oppler Bacillus. — Also known as the Bacillus 
 geniculatus. Owing to the faculty possessed by this organ- 
 ism of growing in the presence of amounts of lactic acid suf- 
 ficient to check the development of all other lactic-acid form- 
 ers, it usually predominates in stomach-contents containing 
 large amounts of this substance. The parent type is com- 
 posed of short rods, but in the presence of considerable 
 amounts of lactic acid these change to a longer form, which 
 occurs singly or in long chains. It is stained brown by Gram's 
 iodin solution. The bacillus affords confirmatory evidence 
 of the presence of a new-growth, like cancer of the stomach, 
 though it may occur in benign conditions. 
 
I02 ESSENTIALS OF BACTERIOLOGY 
 
 Bacillus Violaceus (Schrater). — Origin. — Water. 
 
 Synonym. — B. ianthinum (Zopf). 
 
 Form. — ^A slender rod with rounded ends, three times as 
 long as it is broad, often in threads. 
 
 Spores. 
 
 Motile, flagelia. 
 
 Stain. — ^With Gram and ordinary dyes. 
 
 Cultures. — Agar stroke, moist, ghstening, raised, at first 
 yellow, then violet, inky colored. 
 
 On Potato. — Violet black, moist, abundant growth. 
 
 Gelatin Stab. — Rapidly Uquefying funnel-shaped masses of 
 pigment along the stab. 
 
 Colonies. — ^Hairy outer zone with liquid center, and small 
 masses of opaque blue pigment floating about. 
 
 Biology. — Acid formed in sugar bouillon. No gas. A 
 moderate amount of H2S and indol. Pigment formed is in- 
 soluble in water, slightly soluble in alcohol. 
 
 Facultative anaerobe. 
 
 Temperature. — 22°-25° C. 
 
 Microorganisms Found in Urine. — When freshly passed, 
 urine of a normal state contains no bacteria. By contact 
 with the air and the urinary passages exposed to air, a great 
 number of yeasts, molds and bacteria soon accumulate in the 
 fluid. Bacteria also enter urine through the blood and dur- 
 ing its secretion. 
 
 A number of bacteria have the property of converting urea 
 into carbonate of ammonia. 
 
 The urine should be centrifuged and the deposit then exam- 
 ined. The drying and fixing must proceed very slowly, since 
 otherwise crystals of salts will be precipitated and mar the 
 specimen. 
 
 B. coli are frequently present, especially in acid urine. 
 
 T3^hoid bacilli in 25 per cent, of patients affected with ty- 
 phoid fever. 
 
 Micrococcus Ureae (Pasteur and Van Tiegham). — 
 Origin. — Decomposed urine and in the air. 
 
 Form. — Cocci, diplococci, and streptococci. 
 
SOME COMMON BACTERIA SLIGHTLY PATHOGENIC IO3 
 
 Properties. — Decomposes urea into ammonium carbon- 
 ate; does not liquefy gelatin. 
 
 Growth. — Grows rapidly, needing oxygen; can remain sta- 
 tionary below 0° C, growing again when a higher temperature 
 is reached. 
 
 Colonies on Plate. — On the surface like a drop of wax. 
 
 Stab-cultures. — Looks like a very delicate thread along the 
 needle-thrust. 
 
 Other bacteria are found in urine in various pathologic proc- 
 esses, such as tubercle bacilli, typhoid bacilU, gonococci, and 
 other pyogenic organisms. 
 
 Spirilla. — A number of non-pathogenic spirilla have been 
 described. 
 
 Spirillum Rubriim (Esmarch). — Origin. — Body of a 
 mouse dead with septicemia. 
 
 Form. — Spirals of variable length, long joints, flagella on 
 each end; no spores. 
 
 Properties. — Does not liquefy gelatin; very motile; pro- 
 duces a wine-red pigment, which develops only in absence of 
 oxygen. 
 
 Growth. — Can grow with oxygen, but is then colorless; 
 grows very slowly; ten to twelve days before any sign; grows 
 best at 37° C. 
 
 Gelatin Roll-cultures. — Small, round; first gray, then wine- 
 red colonies. 
 
 Stab-cultures. — A red-colored growth along the whole line; 
 it is deepest below, getting paler as it approaches the surface. 
 
 Sarcina. — Cocci in cubes or packets of colonies. A great 
 number have been isolated, many producing very beautiful 
 pigments. The majority of them found in the air. 
 
 Sarcina Lutea (Schroter). — Origin. — Air. 
 
 Form. — Very large cocci in pairs; tetrads and groups of 
 tetrads. 
 
 Properties. — ^Liquefies gelatin slowly; produces sulphur- 
 yellow pigment. 
 
 Growth. — Slowly, at various temperatures; strongly aerobic. 
 
 Plates. — Small, round, yellow colonies. 
 
I04 ESSENTIALS OF BACTERIOLOGY 
 
 Stab-cultures. — Grows more rapidly, the growth being 
 nearly all on the surface, a few separated colonies following the 
 needle-thrust for a short distance. Agar, a very beautiful 
 yellow, along the stroked surface. 
 
 Sarcina Aurantica. — Flava, rosea, and alba are some of 
 the other varieties. Many are obtained from beer. 
 
 Sarcina Ventriculi (Goodsir) (Fig. 41). — Origin. — Stom- 
 ach of man and animals. 
 
 
 Fig. 41. — Sarcina ventriculi from stomach-contents (X530) (Van 
 Valzah and Nisbet). 
 
 Form. — Colorless oval cocci, in groups of eight and packets 
 of eight. 
 
 Properties. — Does not liquefy gelatin; shows tne reaction 
 of cellulose to iodin. 
 
 Growth. — Rapid. At end of thirty-six hours, round, yellow 
 colonies, from which colorless cocci and cubes are obtained. 
 
 Habitat. — They are found in many diseases of the stomach, 
 especially when dilatation exists. Also normally; increased 
 when fermentation occurs. 
 
BACILLUS OF ANTHRAX I05 
 
 CHAPTER XVII 
 BACILLUS OF ANTHRAX 
 
 Bacillus Anthracis (Rayer and Davaine). — Rayer and 
 
 Davaine, in 1850, first described this bacillus; but Pasteur, 
 and later Koch, gave it the importance it now has. 
 
 Synonyms. — Bactericie du charbon (Fr.); Milzbrand bacil- 
 lus (German) ; bacillus of splenic fever or malignant pustule. 
 
 Origin. — In blood of anthrax-suffering animals. 
 
 
 
 \* 
 
 
 ^ 
 
 - , »' 
 
 \ ; 
 
 Fig. 42. — Bacillus anthracis, stained to show the spores ( X 1000) 
 (Frankel and Pfeiffer). 
 
 Form. — Rods of variable length, largest of pathogenic or- 
 ganisms 4 M to 10 )u in length, nearly the size of a human blood- 
 corpuscle; broad, cup-shaped ends; in bouillon cultures 
 long threads are formed, with large oval spores (Figs. 42, 43). 
 
 Spores. — Single, large, very resistant. Dry heat, 140° C, 
 in three hours; steam in five minutes; necessary to kill. Do 
 
io6 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 not occur in the circulating blood, but develop after death or 
 in artificial media at 30° C. 
 
 Fig. 43-— Anthrax bacilli in human blood (fuchsin staining) (Zeiss one- 
 twelfth oil-immersion; No. 4 ocular) (taken from Vierordt). 
 
 Fig. 44.— Bacillus anthracis, impression preparation, edge of colony; 
 Zettnow prep. (KoUe and Wassermann). 
 
 Liquefies gelatin; immotile. 
 
 Growth.— Grows rapidly, between 12° C. and ^5° C, and 
 
BACILLUS OF ANTHRAX 
 
 107 
 
 requires plenty of oxygen, but may be classed as a facultative 
 anaerobe; grows well in all media. 
 
 Colonies develop in two days; white shiny spots, which 
 appear under microscope as slightly yellowish, granular, 
 twisted balls, Uke a ball of yarn; each separate string or hair, if 
 looked at under high power, being composed of bacteria in 
 threads. (See Fig. 44.) 
 
 Fig. 45- Fig. 46. 
 
 Figs, 45, 46. — Stab-cultures of anthrax in 'gelatin. 
 
 Agar Stroke. — Grayish- white, slightly wrinkled layer with 
 irregular edges. 
 
 Gelatin Stab-cultures. — A white growth with thorn-like 
 processes along the needle-track (like an "inverted fir tree"). 
 Later on, gelatin liquefied, and flaky masses at the bottom. 
 (See Figs. 45, 46.) 
 
I08 ESSENTIAXS OF BACTERIOLOGY 
 
 Potato. — ^^A dry, creamy layer, and when placed in incu- 
 bator, rich in spores. 
 
 Staining. — Readily take the anilin dyes with the ordinary 
 methods. To bring out the cup-shaped concave extremities, 
 a very weak watery solution of methylene-blue is best. 
 Gram positive. 
 
 Spores are stained by the usual method. When several 
 bacilli are joined together, the place of their joining looks like 
 a spore, because of the hollowed ends. Double staining will 
 differentiate the spores. (See Fig. 42.) 
 
 Sections of tissue are stained according to the ordinary 
 methods, taking Gram's method very nicely. 
 
 Pathogenesis. — When mice are inoculated with anthrax 
 material through a wound in the skin, they die in twenty- 
 four hours from an active septicemia, the point of inocula- 
 tion remaining unchanged. 
 
 On autopsy will be found: 
 
 Peritoneum. — Covered with a gelatinous exudate. 
 
 Spleen. — Very much swollen, dark red, and friable. 
 
 Liver. — Parenchymatous degeneration. 
 
 Blood. — Dark red. The bacilli are found wherever the 
 capillaries are spread out, in the spleen, liver, intestinal villi, 
 and glomeruli of kidney, and in the blood itself. Only when the 
 capillaries burst are they found in the tubules of the kidney. 
 
 Mode of Entrance. — The bacilli can be inhaled, and then a 
 pneumonia is caused, the pulmonary cells containing the 
 bacilli; when the spores are inhaled, a general infection occurs. 
 
 Feeding. — The cattle graze upon the meadows, where the 
 blood of anthrax animals has flowed and becc«ne dried; the 
 resistant spores contaminate the grass and so enter the ah- 
 mentary tract; here they then cause the intestinal form of the 
 disease, ulcerating through the villi. Cattle are also in- 
 fected by wading in streams which tannery washings have 
 contaminated. 
 
 Local Infection. — In man usually only a local action occurs; 
 by reason of his occupation — woolsorter, cattle-driver, 
 tanner, etc. — he handles the hides or wool of animals that 
 
BACILLUS OF ANTHRAX lOQ 
 
 have been infected, and through a scratch or sHght wound he 
 becomes infected, and local gangrene and necrosis set in, but 
 death follows in the severer forms from a general pyemia; 
 there is severe edema of the tissues in and about the wound, 
 and pulmonary edema. Wounds about the face and neck are 
 more fatal. 
 
 Pneumonia by inhalation and intestinal ijifection also 
 occur in man. 
 
 Woolsorter's disease is the pulmonary form caused by in- 
 halation of spores from infected wool. 
 
 Susceptibility of Animals. — Dogs, birds, and cold-blooded 
 animals affected the least; white mice, sheep, and guinea-pigs 
 quickly and surely. 
 
 Products of Anthrax Bacilli. — ^A basic ptomain has not been 
 found, but a toxalbumin or proteid, called anthraxin, has been 
 obtained. A certain amount of acid is produced by the viru- 
 lent form, alkali by the weak. 
 
 Attenuation and Immunity. — Cultures left several days in 
 an incubator at a temperature between 40° and 42° C. soon 
 become innocuous, and when injected into animals protect 
 them against the \'irulent form. 
 
 The lymph obtained from lymph-sac of a frog destroys the 
 virulence of anthrax bacilli and spores tem.porarily. 
 
 Hankin obtained an alexin from the blood and spicen of 
 rats, they being naturally immune. It destroyed the anthrax 
 bacilli in vitro, and used by injection in susceptible anim.als, 
 made them immune. It is insoluble in alcohol or water. 
 
 Protective Inoculation. — Animals have been rendered im- 
 mune in various ways — by inoculation of successive atten- 
 uated cultures; also with sterilized cultures — that is, cul- 
 tures containing no bacilli, and with cultures of other bacteria. 
 
 Immune Serum. — That obtained from animals rendered 
 immune by attenuated cultures contains protective substances 
 which seem to have some antitoxic action. 
 
 Habitat. — In the serum about the wound and in the blood 
 anthrax bacilli are readily found. 
 
 The bacillus has never been found free in nature. 
 
no ESSENTIALS OF BACTERIOLOGY 
 
 CHAPTER XVIII 
 BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS 
 
 This very important bacillus was first described, demon- 
 strated, and cultivated by Robert Koch, who made his in- 
 vestigations public before the Physiological Society of Berlin 
 on the twenty-fourth of March, in the year 1882. 
 
 Synonyms. — Mycobacterium tuberculosis . 
 
 V 
 
 
 > 
 
 Fig. 47. — Tubercle bacilli in sputum; carbolfuchsin and methylene-blue 
 (Zeiss one-twelfth oil-immersion). 
 
 Origin. — In various tuberculous products of man and other 
 animals and in the dust containing the discharges. 
 
 Form. — Very slender rods, slightly curved, 2 /x to 4 )Lt in 
 length, about one-quarter the size of a red blood- corpuscle's 
 diameter, their ends rounded, usually solitary, often, how- 
 ever, lying in pairs in such a manner as to form an acute 
 angle. Sometimes they are S-shaped. In colored prepara- 
 
BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS III 
 
 tions little oval spaces are seen in^ the rod which resemble 
 spores, but have none of the properties of spores. (See Figs. 
 
 47, 48.) 
 
 Properties. — Does not possess motility. 
 
 Growth. — Requires special media for its growth, and a tem- 
 perature varying but slightly from 37.5° C. It grows slowly, 
 developing first after teh days, reaching its maximum in 
 three weeks. It is facultative anaerobic. On gelatin it does 
 not form a growth. The media should be slightly acid; 
 
 Fig. 48. — Giant-cell containing bacilli (from a photograph made by Dr. 
 Wm. M. Gray). 
 
 growth mostly on surface. Subcultures grow more rapidly 
 than those direct from lesions. 
 
 Colonies on Blood-serum. — Koch first used blood-serum for 
 culture, and obtained thereon very good growths. Stroke 
 cultures or test-tubes inoculated with small bits of tubercu- 
 lar tissue are placed in a well- ventilated and slightly humid 
 incubator at 37° C. for ten to fourteen days, when small 
 glistening white points appear, which then coalesce to form a 
 dry, white, scale-like growth. Under microscope, composed 
 of many fine lines CQntaining the tubercle bacillus. 
 
 Glycerin-agar. — By adding 4 to 6 per cent, glycerin to 
 
112 ESSENTIALS OF BACTERIOLOGY 
 
 ordinary agar-peptone medium, Nocard and Roux obtained a 
 culture-medium upon which tubercle bacilli grow much better 
 than upon blood-serum, especially after once obtained in 
 pure culture. Bits of tissue are placed on the surface, not 
 rubbed in until after several weeks; then gently crushed and 
 spread over surface ; this hastens growth. 
 
 Stroke cultures are used as with blood-serum. They 
 are placed in incubator after inoculation, and remain there 
 about ten days, at a temperature of 37° C. The cotton plugs 
 of the tubes are covered with rubber caps, the cotton first 
 having been passed through the flame, and moistened with a 
 few drops of subHmate solution. The rubber cap prevents 
 the evaporation of the water of condensation, which always 
 forms and keeps the culture from drying up. 
 
 The growth which occurs resembles the rugae of the stom- 
 ach, and sometimes looks like moistened crumbs of bread. 
 The impression or "Klatsch" preparation shows under the 
 microscope a thick, curled-up center around which threads 
 are wound in all directions. And these fine lines show the 
 bacilli in profusion. 
 
 Potato. — It can be cultivated on slices of potato which are 
 placed in air-tight test-tubes to which glycerin has been added. 
 
 Bouillon. — Bouillon containing 4 per cent, glycerin is a 
 very good medium. Growth on the surface only. 
 
 Pure Cultures from Sputum. — Kitasato recommends the 
 thorough washing, changing the water ten times, of the small 
 masses found in the sputum of tuberculous persons. When 
 such specimens are examined, they show tubercle bacilli 
 alone, and when inoculated in agar, give rise to pure cultures. 
 
 Animal Inoculation for Diagnosis. — When the bacilli are so 
 few in number in sputum or urine as to make their detec- 
 tion difficult, and also when doubt exists as to the identity 
 of acid-fast bacilli found, several guinea-pigs should be in- 
 jected in the groin and smears and sections made from the 
 enlarged glands resulting. 
 
 Varieties. — Branching and other aberrant forms are not 
 rare, and the tendency now is to class the organism with the 
 
BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS II3 
 
 *' higher bacteria," mycobacteria, similar to actinomyces. 
 Other acid-fast bacilli exhibit similar types, and it is possi- 
 ble that the bacillary parasitic form is only one stage in the 
 life-history of the organism. 
 
 Little granules, arranged like streptococci, which take the 
 characteristic stain, and look as if the protoplasm had been 
 destroyed that inclosed them, are frequently found in sputum. 
 Some believe these ''splinters" to develop into regular bacilli 
 in cultures. 
 
 .:^fi> 
 
 Fig. 49. — Tubercle bacillus in sputum (Frankel and Pfeiffer). 
 
 Bovine tubercle bacilli are about one-third smaller than hu- 
 man tubercle bacilli. 
 
 Resistance. — Bacilli in sputum, in dark, cool places may live 
 several months. Dried sputum in sunlight and dust is infec- 
 tive not more than ten days. The bacilli will resist in the dry 
 state a temperature of ioo° C. one hour. In moisture death 
 occurs at 60° C. in a few minutes. 
 
 Chemic Properties. — A waxy substance found in pure cul- 
 tures, due to fatty acids. The fat-free substance is nucleo- 
 
114 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 albumin, and the ash shows a large amount of phosphoric 
 acid. Indol not found. 
 
 Staining. — The tubercle bacilli require special methods to 
 stain them, and a great number have been introduced. They 
 are stained with great difficulty, but once stained, they are 
 very resistant to decolorizing agents, hence called acid-proof 
 or acid-fast. Upon these facts all 
 the methods are founded. 
 
 The resisting action of the bacil- 
 lus to acids is supposed to be due 
 to a pecuhar arrangement of the 
 albumin and cellulose of the cell, 
 rather than to any particular cap- 
 sule around it. A waxy substance, 
 made up of fatty acid, has been 
 found and supposed to account for 
 this resistance. Others believe this 
 substance to be an alcohol. 
 
 It will be necessary to describe 
 only those methods principally in 
 use; and as the examination of 
 sputum for bacilH is of so frequent 
 an occurrence and so necessary, it 
 is well to detail in particular the 
 method of staining. 
 
 Starting with the sputum, we 
 
 search for little clumps or rolled-up 
 
 masses; if these are not present, 
 
 the most solid portions of the 
 
 mucus are brought with forceps 
 
 upon a clean cover-glass; very little 
 
 suffices. With another cover-glass 
 
 the mass is pressed and spread out evenly. Drawing one glass 
 
 over the other, we obtain two specimens, and these are put 
 
 aside or held high over the flame until dry. 
 
 When the preparation is dry and has been fixed by passing 
 through the flame three times, carbolfuchsin is dropped on 
 
 Fig. 50. — Bacillus tuber- 
 culosis; glycerin agar-agar 
 culture, several months old 
 (Curtis). 
 
BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS II5 
 
 the cover-glass and held over the flame until the stain boils; 
 fresh stain is added, the boiling continued for a minute. 
 Then the excess of stain is removed with edge of filter-paper. 
 Decolorize in 25 per cent, nitric or 2 per cent, hydrochloric 
 acid. The excess of acid is then washed out with 95 per 
 cent, alcohol until no further color is imparted to the alcohol, 
 and the smear is gray or light pink in color. The preparation 
 is then washed with water and counterstained with aqueous 
 methylene-blue for ten to thirty seconds. 
 
 The Rapid Method {B. FrdnkeVs Method, Modified by Gab- 
 bet), — The principle is to combine with the contrast stain the 
 decolorizing agent; but the preparations are not permanent; 
 the method, however, is very useful. 
 
 Two solutions are required: one of Ziehl's carbolfuchsin; 
 the other, Gabbet's acid irethylene-blue. (See Formula No. 
 X, on p. 51.) 
 
 The cover-glass containing the dried sputum is passed 
 three times through the flame, as described in the general 
 directions. It is then placed in the carbolfuchsin solution 
 five minutes (cold), or two minutes in the hot, immediately 
 transferred to the second solution, the acid blue, where it 
 remains one minute, then washed in water. The preparation 
 is dried between filter-paper and mounted. Examined with 
 oil-immersion. 
 
 Slow Method. — The above method may also be used with- 
 out heating, though in this case a much longer time is required 
 before the bacilli take up the stain. The preparation is left 
 in a small dish or beaker full of carbolfuchsin for eight to 
 ten hours, and theri decolorized and counterstained in the 
 way described above. The method is less liable to produce 
 artefacts than the quick method, but is not much used on 
 account of the time it takes. 
 
 Examination in Urine. — In urine, owing to the almost in- 
 e\itable contamination with the smegma bacillus, special 
 methods are necessary to avoid error. The preparation may 
 be left in 97 per cent, alcohol for eight hours, when the 
 smegma bacillus will have become decolorized, or Pappenheini's 
 
Il6 ESSENTIALS OF BACTERIOLOGY 
 
 method may be used: (i) Smear and fix as usual; (2) stain 
 with hot carbolfuchsin for two minutes, pour off the surplus 
 dye without washing; (3) counterstain and decolorize by 
 pouring five times over the preparation the following solu- 
 tion: A I per cent, alcoholic solution of corallin is saturated 
 with methylene-blue and 20 parts of glycerin added. Wash 
 in water, dry with blotting-paper, then in the air, and exam- 
 ine. The tubercle bacilli are stained red, smegma bacilli, 
 blue. 
 
 Examination of Milk for Tubercle Bacilli. — Place a drop 
 of the sample on a cover-glass and mix it with two drops 
 of a I per cent, solution of sodium carbonate. The cover- 
 glass is then gently warmed until evaporation is complete. 
 The saponified fat is then stained, as the ordinary cover-glass 
 preparation. Only a few times has any one succeeded in 
 discovering the bacillus in milk. 
 
 Other Acid-fast Bacteria. — The bacillus of leprosy re- 
 sembles the tubercle bacillus in its staining properties, but 
 gives up the carbolfuchsin more easily and is usually de- 
 colorized by the acid and alcohol. It is colored blue by Pap- 
 penheim's method. 
 
 Acid-fast bacilli have also been obtained from timothy 
 grass, butter, milk, manure, and the surfaces of animal bodies, 
 but differ from the tubercle bacillus in cultural characteristics. 
 
 Water has been found to contain acid-fast bacilli; care 
 should be taken to test the water used previously to any im- 
 portant examination for tubercle bacilli. 
 
 Biederfs Method of Collecting Bacilli. — When the bacilli 
 are very few in a great quantity of fluid, as urine, pus, abun- 
 dant mucus, etc., Biedert advises to mix 15 c.c. of the fluid 
 with 75 to 100 c.c. water and a few drops of potassium or 
 sodium hydroxid, then boiling until the solution is quite 
 thin. It is placed in a conical glass for two days, and bacilli 
 with other morphologic elements sink to the bottom of the 
 glass; when the supernatant liquid is decanted, the residue 
 can be easily examined. In this way bacilli were found that 
 had eluded detection examined in the ordinary manner. 
 
BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS II 7 
 
 The centrifugal machine is used either in connection with 
 Biedert's sediment method or without, to obtain the soUds 
 suspended in urine or serum. 
 
 Antiformin Method. — A mixture of chlorin water and so- 
 dium hydroxid; chlorin is liberated, and this dissolves most 
 of the organisms in the sputum and the mucus, leaving un- 
 altered the tubercle bacillus. Dilute thick sputum with dis- 
 tilled water, add one-quarter volume antiformin, mix until 
 solution is effected; add alcohol, equal volume, and allow 
 mixture to stand eighteen hours. Prepare cover-slip prepa- 
 rations from this. 
 
 Staining Bacillus Tuberculosis in Tissue {Sections). — The 
 general method of Gram can be used, but the better way is 
 to use the following: 
 
 Warm carbolfuchsin, fifteen to thirty minutes. 
 
 5 per cent, sulphuric acid, one minute. 
 
 Alcohol, until a light-red tinge appears. 
 
 Weak methylene-blue, three to five minutes. 
 
 Alcohol, for a few seconds. 
 
 Oil of cloves, until cleared. 
 
 Canada balsam, to mount in. 
 Instead of carbolfuchsin, alcoholic solution of fuchsin or 
 anilin-water fuchsin can be used, but the sections must re- 
 main in the stain overnight. 
 
 Hardened Sputum and Sectioning. — Sputum can be hard- 
 ened by placing it in 98 per cent, alcohol. Thin sections can 
 be obtained by imbedding the hardened sputum in celloidin. 
 The sections are then stained as ordinary tissue sections. 
 
 To Preserve Sputum. — Sputum can be preserved for future 
 use by placing it in alcohol, w^here it can be kept for months. 
 Cover-glass preparations can then be made by softening the 
 coagula with a small amount of liquor potassa. 
 
 Pathogenesis. — When a guinea-pig has injected into its 
 peritoneal ca\ity some of the diluted sputum containing tu- 
 bercle bacilli, it perishes in about three weeks, and the follow- 
 ing picture presents itself at the autopsy: at the point of 
 inoculation there is a local tuberculosis — little tuberculous 
 
Il8 ESSENTIALS OF BACTERIOLOGY 
 
 nodules containing the characteristic bacilli. In the lungs 
 and the lymphatics similar tubercles are found — a general 
 tuberculosis. 
 
 If the animal lingers a few weeks longer, the tubercles 
 becomes necrosed in the center and degeneration occurs, the 
 periphery still containing active bacilli, cavities ha\dng formed 
 in the center. 
 
 Since the bacilH die in course of time, killed by their own 
 products, their number forms no correct guide of the dam- 
 age present: even their absence in the sputum does not pre- 
 clude the absence of a tuberculous process. // is their pres- 
 ence only that warrants a positive declaration. The number of 
 bacilli in a given specimen is no indication of the severity of 
 the disease. 
 
 They are found in the blood only when a vessel has come 
 in direct contact with a tuberculous process through rupture 
 or otherwise. They have been found occasionally in other 
 secretions — milk, urine, etc. 
 
 Man is infected as follows: 
 
 Through Wounds. — Local tuberculosis. 
 
 Through Nutrition. — Milk and meat of tuberculous ani- 
 mals. Phthisical patients swallowing their own sputum and 
 causing an intestinal tuberculosis. 
 
 Inhalation. — This is the most usual way, probably consti- 
 tuting the cause in nine-tenths of the cases in adults. 
 
 The sputum of phthisical patients expectorated on the 
 floors of dwelling-houses, in handkerchiefs, etc., dries, and 
 the bacilli set free are placed in motion by the wind, or rising 
 with the dust, are thus inhaled by those present. When the 
 sputum is kept from drying by expectoration in vessels con- 
 taining water, this great danger can be avoided. 
 
 Intra-uterine or placental infection has been demonstrated, 
 but is a great rarity. The ovum or human semen is seldom 
 if ever infected, although tubercular infection of the testicle 
 is common. 
 
 Nearly all the cases of supposed heredity can be explained 
 as follows : the young children, p ossessing very httle resist- 
 
BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS II9 
 
 ance, are constantly exposed to the infection through inhal- 
 ation, and to intestinal infection through milk and other foods. 
 
 Immunity. — No one can be said to be immune, though per- 
 sons who have been greatly weakened offer less resistance 
 than healthy individuals. 
 
 Bovine and Human Tuberculosis. — Tuberculosis in 
 Animals. — Tuberculosis is probably the most widely dis- 
 seminated disease among domestic , animals, and affects 
 cattle, pigs, horses, dogs, cats, the smaller ruminants, birds, 
 and even turtles and fish. The conclusion of Koch, made 
 public in his address to the Tuberculosis Congress in 1901, 
 that human and bovine tuberculosis are distinct and that in- 
 fection of human beings from cattle occurs so seldom that no 
 general regulations to restrict it are necessary, has found 
 few adherents. In 1908 Koch reiterated his idea and chal- 
 lenged his opponents to bring proofs to the contrary. Con- 
 clusions at this writing seem to be that go per cent, of all 
 puhnonary cases in adult man are not due to bovine infection. 
 In children under five, however, 10 per cent, of the intestinal 
 tuberculosis and cervical adenitis are due to the bovine 
 type of infection through milk of diseased cows. It is true 
 that certain differences exist between human and bovine 
 tubercle bacilli, the latter appearing to be more virulent to 
 animals, and it is a fact that cattle are very slightly suscepti- 
 ble to the human bacillus, but it is not likely that the con- 
 verse is so. Children are particularly liable to infection 
 through the gastro-intestinal tract, and it has been shown 
 that the uninjured mucosa of the infant's intestine is per- 
 meable to bacilli, so that the pulmonary disease in the 
 young may often be the result of tuberculous bronchial nodes 
 secondary to tuberculous glands of the mesentery. 
 
 Various observations on animals have shown that the 
 bacillus occurring in each species has acquired certain special 
 characteristics regarding growth and virulence. The bacilli 
 causing tuberculosis in the cold-blooded animals have de- 
 parted farthest from the human type, those of birds to a less 
 degree, and those of cattle least of all. 
 
I20 ESSENTIALS OF BACTERIOLOGY 
 
 Products of Tubercle Bacilli. — The true nature of the 
 tubercle toxin is not yet clear. It is not unlikely that several 
 toxic bodies differing from one another in their properties are 
 produced. Koch's tuberculin (1890), a bacterioprotein, was 
 obtained by filtering through unglazed porcelain, concen- 
 trated glycerin bouillon cultures of tubercle bacilli. It was 
 speedily shown to be devoid of curative power, and is now 
 used mainly for diagnosing the disease in cattle. In healthy 
 animals little or no reaction is produced by the injection of 30 
 to 40 eg. of tuberculin, but if tuberculous, the temperature 
 rises 2° to 3° F . in eight to twelve hours, and remains elevated 
 for a like period of time and may in larger doses prove fatal. 
 It is dangerous unless used carefully. 
 
 Tuberculocidin. — This is an albuminoid obtained from the 
 original tuberculin by precipitation with alcohol. Klebs 
 used it as a treatment for tuberculosis. 
 
 Tuberculin residuum, an emulsion from the residuum, 
 hence the name, T. R., is an extract made from dried and 
 powdered living bacilli, and was recommended by Koch in 
 place of the original or old tuberculin, O. T. 
 
 Koch^s bacillen emulsion {B. E.) is similar to tuberculin R, 
 and is a glycerin emulsion of crushed bacteria, this being the 
 entire substance instead of an extract. Theo. Smith recom- 
 mends virulent uncrushed bacteria killed by moderate heat. 
 
 Denys^ B. F. (bouillon filtrate) tuberculin is a filtrate of 
 Hquid cultures to which 0.25 per cent, phenol has been 
 added and allowed to stand two weeks. It is prepared in 
 eight dilutions. 
 
 Opsonic Treatment. — In recent years the use of tuberculin 
 R has again been brought forward by Wright and others and 
 curative claims made for it. It is used in very small doses — 
 TTrV"o milligram at intervals of several days, and the effect on 
 the opsonic index carefully watched. 
 
 Use of Tuberculin. — In the use of tuberculin severe reactions 
 are to be avoided. The smallest dose possible is commenced 
 with. Trudeau uses for afebrile cases a solution containing 
 xiy^TFirniilligram, Hquid measure, Koch's B. E., or Denys' B. F., 
 
BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS 121 
 
 increasing i decigram of the solution every three days until 
 I c.c. of the pure filtrate can be injected without causing any 
 reaction. A negative reaction sometimes occurs in well- 
 advanced cases, and is, therefore, not a proof of the absence 
 of disease. The reaction is due to the stimulation of irri- 
 tating proteins. Yeast nucleins and other substances have 
 a similar action. This treatment must extend over months. 
 Tuberculin immunity does not last indefinitely. Under this 
 careful treatment, associated with open air, proper food, and 
 general hygiene, Trudeau and his followers have had some 
 very good results. 
 
 Von Pirquet Test. — TubercuHn applied to the abraded 
 skin like a vaccination w^ith cow-pox causes a local reaction 
 in tuberculous infants and no reaction in healthy ones. It 
 is not applicable to children over eighteen months of age. 
 The test is so sensitive that it will be positive in the majority 
 of instances, because the majority of people have at some 
 time been affected with tuberculosis or exposed sufficiently 
 to have within them sensitive bodies that are easily stimu- 
 lated. 
 
 Ophthalmic Tuberculin Reaction of Calmette. — A modified 
 form of tuberculin is placed on the conjunctiva of an indi- 
 vidual suspected of having tuberculosis. In a few hours a 
 congestion, more or less severe, results, and lasts several 
 days. In healthy persons no reaction occurs. The test is 
 claimed to be harmless, though severe reactions have been 
 reported in tuberculous patients, and even in healthy persons 
 a second appHcation to the same eye may cause an inflam- 
 matory reaction. 
 
 Morons Test. — An ointment of tuberculin and lanolin, equal 
 parts, rubbed in the skin of the arm. A crop of papules de- 
 velops in twelve to twenty-four hours if test is positive. 
 
 Agglutination. — Arloing and Courmont have described 
 an agglutination reaction for the tubercle bacillus similar to 
 the Widal reaction of typhoid fever. (See p. 140.) It is 
 very unreliable, however, and but little importance is at- 
 tached to it. 
 
122 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Antituherculous Serum. — The attempts to produce an 
 effective serum have so far been unsuccessful. Marmorek, 
 by growing the bacillus on a special serum obtained by in- 
 jecting calves with the leukocytes of guinea-pigs, has secured 
 a toxin which he used to immunize horses, and the serum so 
 obtained has been tried with encouraging results, but its 
 value is still doubtful. Several other sera have been intro- 
 duced, but none of them has shown any lasting virtues. 
 
 Lepra Bacillus (Hansen). — Origin. — In 1880 Armauer 
 Hansen declared, as the result of many years' investigation, 
 
 that he found specific bacil- 
 lus in all leprous processes. 
 
 Form. — Small slender rods, 
 somewhat shorter than tu- 
 bercle bacilli, otherwise very 
 similar in appearance. 
 Neither in the form nor 
 staining reactions can B. 
 lepra be distinguished from 
 B. tuberculosis. 
 
 In the interior of the cell 
 two or three oval spaces are 
 usually seen, not believed tc 
 be spores. 
 
 They are immotile. 
 Growth. — Bordoni-Uffred- 
 uzzi have obtained growths 
 upon blood-serum to which peptone and glycerin had been 
 added, but the accuracy of this observation was doubted, 
 and not until Clegg, in 1909, and Duval, in 1910, in work in 
 the Philippine Islands devised special media was it possible 
 to obtain readily initial and subcultures. 
 
 The method depends upon supplying the organism with 
 albumin partially metabolized. Clegg prepared this by 
 planting the lepra bacilH on media containing ameba and 
 bacteria; then, by short sterilization, destroying these, while 
 the resistant B. lepra lived on. Duval, by adding trypsin to 
 
 Fig. 51. — Pure culture of bacil- 
 lus of leprosy, showing the charac- 
 teristic morphology and arrange- 
 ment of the bacilli (Duval). 
 
BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS 1 23 
 
 egg-albumin or blood-serum, was able to change the protein 
 sufficiently without requiring ameba or bacterial digestion. 
 
 The leprous nodule is cut in small sHces and spread over 
 an albumin slant or Petri plate, and the surface covered with 
 I per cent, solution trypsin and placed in oven at 37° C. for 
 ten days. 
 
 The growth is moist and becomes yellow after several 
 generations; it is on surface. 
 
 Staining. — B. lepra resist the decolorizing action of acids, 
 as the tubercle bacilli, but they are more easily stained, re- 
 quiring but a few minutes more with the ordinary watery solu- 
 tions. They take Gram's stain readily. 
 
 Pathogenesis. — Arning inoculated a prisoner with tissue 
 obtained from leprous patients and produced true leprosy, 
 but this was a susceptible native and the evidence is not 
 clear. Duval, by repeated injections of large amounts of 
 pure culture, has produced leprosy in mice, guinea-pigs, and 
 monkeys. 
 
 Rabbits which have been infected through the anterior 
 chamber of the eye show^ed the lepra nodules (containing the 
 lepra bacilli) diffused through various organs. 
 
 In man the skin and peripheral nerves are principally 
 affected, but the lymphatic glands, liver, and spleen can also 
 become the seat of the lepra nodules. The lepra cells which 
 compose these nodules contain the bacilli in large numbers. 
 By applying a vesicant to the leprous skin, the serum there- 
 by obtained will contain great numbers of bacilli. This is a 
 simple diagnostic test. 
 
 Method of Infection. — ^Not yet determined; the air, soil, 
 water, and food of leprous districts have been carefully ex- 
 amined without result. The nasal secretion is very infectious. 
 Intimate contact over a long period seems necessary, but the 
 records of leper asylums show that very few cases ever de- 
 velop among the attendants. 
 
 Smegma Bacillus of Alvarey and Tavel. — Lustgarten, in 
 1885, through a certain staining process, found peculiar 
 bacilU in syphilitic tissues which he thought had a direct 
 
124 ESSENTIALS OF BACTERIOLOGY 
 
 connection with the disease. But this has been disproved 
 and the cause of syphiUs has been found in a protozoon 
 which has been called Spirochaeta palHda, which see (p. 209). 
 The smegma bacillus is found in and about the genital or- 
 gans, is an acid-fast bacillus which resembles the tubercle 
 bacillus in form, but is easily decolorized with alcohol, thus 
 differing from the latter. It has no pathogenic properties, but 
 is found at times in the throat and may be mistaken for B. 
 
 rT 
 
 / 
 
 
 ^"^1#'^ "^ 
 
 
 fe% 
 
 
 Fig. 52. — Bacillus of glanders from a culture upon glycerin agar-agar 
 (Xiooo) (Frankel and Pfeiffer). 
 
 tuberculosis. Differentiated in staining, according to Pap- 
 penheim's Method. 
 
 Bacillus of Glanders (Bacillus Mallei (Loffler-Schiitz) ; 
 Rotz-bacillus) . — Origin. — In the "farcy buds" or little 
 nodules of the disease, by Loffler and Schiitz, in 1882. 
 
 Form. — Small slender rods, about the size of the tubercle 
 bacillus. The ends rounded. Never appearing in large col- 
 lections, usually singly (Fig. 52). Granules like spores 
 appear in some cultures; branched forms are found. 
 
BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS 1 25 
 
 Properties. — They are not motile; do not produce gas; 
 some pigment on potato. 
 
 Growth. — The growth occurs between 25° and 40° C. — best 
 at 37° C; it is very sparse upon gelatin, but on glycerin-agar 
 or blood-serum a very abundant growth occurs. Easily de- 
 stroyed by heat, but cultures sealed and protected from 
 light may live several months. 
 
 Colonies. — On agar or glycerin-agar there appear in two to 
 three days small white glistening drops, which under micro- 
 scope seem as round granular masses with an even periphery, 
 similar to young B. typhi colonies. 
 
 Stroke Cultures. — On glycerin-agar and blood-serum small 
 transparent drops of whitish or grayish color, which soon 
 coalesce to form a broad band like B. coli. 
 
 Potato. — An amber-colored, honey-like growth which grad- 
 ually turns red, then brown, and greenish-brown around it. 
 Weakly acid potatoes are a good medium and give the most 
 typical growth. 
 
 Staining. — Gram negative. Since the bacillus is very easily 
 decolorized, some special methods have been recommended. 
 Loffler's and Klihne's solutions for cover-glass and sections. 
 (See Staining.) 
 
 Pathogenesis. — If horses, field-mice, or guinea-pigs be inocu- 
 lated subcutaneously with but a very small quantity of cul- 
 ture, a local affection results, followed some time after by 
 a general disturbance; ulcers form at the point of inocula- 
 tion — little nodules, which then caseate, leaving scars and 
 involving the lymphatics; metastatic abscesses then occur in 
 the spleen and lungs, and death from exhaustion. Cattle, 
 pigs, and rabbits are not easily affected; man is readily 
 attacked. The bacilli gain entrance to the blood and urine. 
 Nasal glanders occurs whatever the mode of inoculation. In 
 the horse the type is more chronic than in the mule. A catar- 
 rhal nasal discharge occurs, highly infectious. In the cutane- 
 ous variety, the enlarged lymphatics or nodes which develop 
 are cdiW^di farcy-huds. 
 
 Manner of Infection. — Glanders, being a highly contagious 
 
126 ESSENTIALS OF BACTERIOLOGY 
 
 disease, it requires but a slight wound to allow it to gain 
 entrance. 
 
 In horses the primary sore seems to be at the nasal mucous 
 membrane. In man it affects those attending horses and is 
 usually on the fingers, and terminates fatally within three 
 weeks. Chronic glanders may last several years and end in 
 recovery. 
 
 Mallein. — ^A substance called mallein has been obtained 
 from the cultures grown in glycerin bouillon. It gives a re- 
 action when injected into cattle suffering from glanders, and 
 is said to be useful in diagnosing the disease. The reaction is 
 specific and never fails to reveal the presence of infection. 
 
 The inoculation of a guinea-pig intraperitoneal^ with some 
 of the suspected discharge will produce an orchitis if the 
 glanders bacillus is present, which is quite characteristic and 
 helpful in the diagnosis. 
 
 CHAPTER XIX 
 DIPHTHERIA BACILLUS 
 
 Bacillus of Diphtheria (Klebs-LoflBler) . — Origin. — 
 Klebs found it in diphtheritic membrane in 1883; it was iso- 
 lated by Loffler in 1884. 
 
 Form. — Small, slightly curved rods about as long as tu- 
 bercle bacilli and twice as broad; i /i to 6 /x in length; the 
 ends are at times swollen; spores have not been found. Their 
 form is, however, very variable — sometimes much longer 
 than usual, one end often greatly knobbed. Normal bacilli 
 are found only in membrane. 
 
 - Stained forms are characteristic, since the ends are more eas- 
 ily colored than the center, and usually the bacillus stains in 
 segments, so that it seems to be made up of very short sec- 
 tions or beaded. At first sight it appears like a chain of cocci. 
 
DIPHTHERIA BACILLUS 1 27 
 
 Small granules, the Babes-Ernst granules, are shown by 
 the special staining of Neisser. 
 
 Properties. — B. diphtheria is immobile; does not liquefy 
 gelatin. Is not very resistant, being destroyed by a tempera- 
 ture of 50° C, but may live on blood-serum for months. 
 Acid is produced in sugar media. 
 
 Growth. — Grow readily on all media, but best on blood- 
 serum mixtures, between temperatures of 20° and 40° C. 
 They are facultative anaerobic; they grow quite rapidly and 
 
 ^i 
 
 Fig. 53. — Diphtheria bacilli frwni ^ cliuic on blood-serum, stained 
 by Loffler's methylene-blue solution, showing deeply stained points 
 (X2000) (Wright and Brown). 
 
 profusely. Egg cultures (Hueppe's method) give good 
 growths. Passing currents of air increase the growth; on 
 agar, growth is slow. 
 
 Colonies on Agar Plates. — At 24° C. little round colonies, 
 white under low power, granular center ; irregular borders. 
 
 S tab-cultures. — Small, white drops along the needle-track. 
 In glycerin-agar a somewhat profuse growth. Media should 
 be slightly acid. 
 
 Potato. — On alkaline surface, a gra)dsh layer in forty-eight 
 hours. 
 
128 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Blood-serum {After Loffler). — See p. 69. 
 In a few hours (eight to sixteen) on the white opaque sur- 
 face a sUght moisture is noticeable which, if examined, is 
 composed of bacilli. In twenty-four hours small round 
 colonies are found which seem to ar- 
 range themselves concentrically. The 
 growth becomes more abundant, and 
 the individual colonies larger and yel- 
 lowish (Fig. 54). On blood-coagulum 
 (see p. 72) the growth is usually gray 
 and the margins of the culture crenated. 
 Often a diagnosis can be made in four 
 hours if the serum-tubes are kept in the 
 oven at 37° C. In milk, abundant 
 growth, without curdling. 
 
 Bouillon. — In bouillon an abundant 
 growth takes place, and this medium is 
 used to obtain the toxins. 
 
 Staining. — Is positive by Gram's 
 method. Stained best with Loflfler's al- 
 kaline methylene-blue. Neisser's double 
 stain (see p. 52) shows granules, blue 
 black, and body, brown. 
 
 Pathogenesis, — By inoculation, ani- 
 mals, which naturally are not subject 
 to diphtheria, have had diphtheritic 
 processes develop at the site of infec- 
 tion; hemorrhagic edema then follows, 
 and death. 
 
 No agglutinins are developed in the 
 serum. 
 
 In rabbits paralyses develop, and 
 when the inoculation occurs upon the 
 trachea, all the prominent symptoms of diphtheria show 
 themselves. 
 
 Manner of Infection in Man. — The exact way is not yet 
 known. It is supposed that the mucous membrane, altered in 
 
 Fig. 54. — Bacillus 
 diphtheriae; agar-agar 
 culture (photograph 
 by Dr. Henry Koplik) . 
 
DIPHTHERIA BACILLUS 1 29 
 
 some manner, the diphtheria bacillus then gains entrance and 
 the disease develops. The bacilli may be found in healthy 
 indi\dduals who may act as a source of infection to sus- 
 ceptible individuals without themselves becoming infected. 
 They are seldom found in blood or other tissues; the symp- 
 toms arise mainly from the absorption of the toxin. 
 
 Prevalence of Bacillus DiphthericB. — Examinations made on 
 a large scale of the throats of supposedly healthy individuals 
 have shown that the Bacillus diphtheriae is rather widely dis- 
 tributed. Not only does it linger for many weeks in the 
 throats of persons recently recovered from the disease, but it 
 
 Fig- 55. — Bacillus diphtheriae, from a pure culture. 
 
 is found in the caretakers, nurses, etc., and there are allied 
 organisms, with more or less pathogenicity, that have been 
 found in atrophic rhinitis, in conjunctivitis, and in the throats 
 of unexposed normal individuals. 
 
 Pseudodiphtheria. — The pseudohacillus of Hoffman is be- 
 lieved by some investigators to be but a weakened diphtheria 
 bacillus that has lost its toxic power, but its true relation is 
 not settled. It is morphologically identical and at times is 
 found side by side with the true bacillus. It grows well 
 on agar, shows no granules with Neisser stain, and, contrary 
 to B. diphthericB, does not produce as much acid in dextrose 
 broth. 
 
 9 
 
130 ESSENTIALS OF BACTERIOLOGY 
 
 Methods of Diagnosis. — A small piece of exudate or some 
 secretion from phar^^nx, tonsil, or nares is obtained on a ster- 
 ile cotton swab and transferred, as soon as possible, to the sur- 
 face of two or more blood-serum tubes (if these are not avail- 
 able, the swab should be placed in a sterile test-tube or bottle, 
 and sent to the laboratory at once). The inoculated tubes 
 are placed in the incubator at 37° C, and examined in twelve 
 hours. If a growth is visible, a slide is made and stained 
 
 
 -*4 
 
 HT 
 
 
 
 Fig. 56. — Bacillus diphtheriae, from a culture upon blood-serum (Xiooo) 
 (Frankel and Pfeiffer). 
 
 with Loffler's and Neisser's stain, and if bacilli are present, 
 with characteristic granules, the diagnosis of diphtheria is 
 most probable. Negative results are not to be depended on. 
 The use of antiseptics, gargles or the failure to obtain a portion 
 of the exudate may give a negative culture result in a case of 
 diphtheria. If the symptoms are suggestive, it is best to use 
 antitoxin and isolate the patient, notwithstanding a negative 
 report from the laboratory. If there are no clinical signs, 
 the growth should be tested for toxicity by inoculating a 
 
DIPHTHERIA BACILLUS I3r 
 
 guinea-pig; it should be grown in alkaline sugar bouillon and 
 tested in two days for acid. The xerosis and Hoffman's 
 bacilH are not pathogenic for guinea-pigs. 
 
 Products. — But it is not the mere presence of the bacillus 
 that gives rise to trouble: certain products which generate it 
 get into the system and produce the severe constitutional 
 symptoms. 
 
 Toxins of Diphtheria. — Roux and Yersin, in 1888, discov- 
 ered the toxin and showed that the injection of the filtered 
 culture bouillon (that is, freed of all diphtheria bacilli) gave 
 rise to the same palsies as when the bacilli themselves were 
 introduced. 
 
 The toxins may be separated from three-weeks-old bouillon 
 cultures by filtration. They are not albumins and are very 
 complex. Ehrlich claims three forms: one he calls toxone; 
 the other, toxin; the toxone produces paralytic symptoms 
 and appears to be less affected by antitoxin; the third, toxoid, 
 combines with antitoxin. The toxins are highly poisonous — 
 o.ooi c.c. may be sufficient to kill a guinea-pig in less than 
 twenty-four hours. The substance is unstable, losing its toxic 
 power gradually. Heating at 58° C. for two hours is destruc- 
 tive, but drying renders it more stable. Direct sunlight 
 destroys its power in a few hours. Boiling in five minutes. 
 If kept cold and in the dark, it may remain active two years. 
 Alcohol and calcium chlorid precipitate the toxic element. 
 
 Antitoxin. — Behring, in 1890, found that animals rendered 
 immune had a principle in their blood that was antagonistic 
 to the development of the toxin. 
 
 Immunity. — Brieger and Frankel, by injecting 10 to 20 c.c. 
 of a three-weeks-old culture of diphtheria bacilli which had 
 been heated at 70° C. for one hour, produced an immunity in 
 guinea-pigs against the virulent form. This active principle 
 is unknown chemically, but has been called antitoxin. 
 
 The toxin generated by the germ is supposed to be neutral- 
 ized by the antitoxin and prevented from injuring the body 
 tissues. The value of antitoxin in diphtheria seems to be 
 established beyond a doubt, and it is the claim of eminent 
 
132 ESSENTIALS OF BACTERIOLOGY 
 
 sanitarians that the death-rate from this disease has been re- 
 duced from 66 per 100,000 to 19 per 100,000 since the use of 
 antitoxin (Park). 
 
 The strength commonly employed in human beings is 5000 
 imits, and as much as 120,000 units may be given without 
 detriment in severe cases. If this amount is injected sub- 
 cutaneously and even intravenously into a child suffering 
 from diphtheria in the earlier stages (second to third day), 
 the disease is often arrested. The membrane begins to dis- 
 appear, and in two or three days has vanished. The con- 
 stitutional symptoms are likewise greatly influenced by the 
 injection. For prophylaxis and immunizing well persons 
 1000 to 3000 units are employed. 
 
 In such conditions as asthma severe and fatal results have 
 followed the use of the serum, and some cases of peculiar sen- 
 sitiveness to horse serum (see Anaphylaxis) have been re- 
 ported, fatal results having occurred, but fortunately such 
 mishaps are exceedingly rare. 
 
 The antitoxin has no influence on the bacteria themselves; 
 their virulence and length of residence in the body are not 
 lessened. 
 
 Preparation of Antitoxic Serum. — Horses are rendered 
 immune by gradually increased doses of diphtheria toxin, the 
 power of the toxin having first been standardized by its neu- 
 tralization with some standard antitoxin in powdered form. 
 
 Preparation of Toxin. — ^The bacillus is grown in veal broth 
 with an alkaline reaction. (Acids prevent toxin formation.) 
 There should be a free supply of oxygen, and, therefore, large 
 shallow flasks are used. The maximum toxicity is developed 
 in seven to ten days. The strength should be -s^q- c.c, fatal 
 for 500-gram guinea-pig. 
 
 The toxin is at first injected subcutaneously, then intraven- 
 ously, and after several months' treatment a resistance is ob- 
 tained that will withstand 300 to 500 times the original lethal 
 dose. The horse is then bled, and from five to nine liters 
 withdrawn; this is then allowed to coagulate, and under very 
 careful precautions the serum is placed in sterile packages, 
 
THE COLON-TYPHOID GROUP I33 
 
 its strength having first been compared with a standard fur- 
 nished by the United States Government. Unless kept in 
 the dark and at low temperature, it loses strength rapidly. 
 
 Antitoxic Unit. — An immunity unit, according to Ehr- 
 lich, is the amount of antitoxic serum which will neutral- 
 ize 100 times the minimum lethal dose of toxin, when serum 
 and toxin mixed and injected into a 250-gram guinea-pig 
 does not cause death in four days. Thus, if the serum will 
 protect in doses of -jV c.c, then each cubic centimeter has 
 50 units' power, and 20 c.c. will contain 1000 units, or will be 
 sufficient to neutralize an amount of toxin that would be 
 fatal for 25,000 kilos (12,500 pounds) of guinea-pigs, or 
 100,000 pigs weighing 250 grams each. The serum is con- 
 centrated by precipitation and separation from the blood- 
 serum of the pseudo-globulins containing the antitoxic prin- 
 ciple, so that 10 c.c. contain more units than formerly. The 
 doses given now are much larger than when first introduced. 
 As much as 100,000 units have been employed in a single 
 case. (Sera containing 1000 units to i c.c. are now being 
 marketed.) 
 
 Streptococcus in Diphtheria. — Streptococci have been 
 found quite constant in diphtheria, but they resemble the 
 Streptococcus pyogenes, and have no specific action. 
 
 CHAPTER XX 
 
 THE COLON-TYPHOID GROUP 
 
 In this group are placed a variety of organisms similar in 
 form and growth and having many biologic properties in 
 common, but differing in pathogenesis. The more impor- 
 tant members of this group are: Bacillus coli, B. typhosus ^ 
 B. enteritidis, B. dysenteries. Another closely related organism 
 is the B. suipestifer (hog cholera). The form is usually a 
 plump rod with rounded ends. Gram-negative. No spores. 
 
134 ESSENTIALS OF BACTERIOLOGY 
 
 Motile, all possessing flagella, on gelatin surface, a leaf -shaped, 
 thin colony. They all reduce nitrate to nitrite. Gelatin not 
 liquefied. Ferment sugar broth; some produce acid in milk, 
 some do not. Some form gas in sugar, some not. 
 
 Bacillus Coll (Escherich). — Synonyms. — Bacterium colt 
 commune; Colon Bacillus. — Found (1886) in human feces, in- 
 testinal canal of most animals, in pus and water. 
 
 Form. — Short rods, with very slow movement, often asso- 
 ciated in little masses, resembling the typhoid germ, fiagel- 
 
 Fig. 57. — Bacillus coll communis, from an agar-agar culture (X 1000) 
 (Itzerott and Niemann). 
 
 lated, not forming spores (Fig. 57). Very short round ends; 
 oval forms are found in animal tissues. 
 
 Properties. — Does not liquefy gelatin, causes fermentation 
 in saccharine (dextrose) solutions in the absence of oxygen, 
 forming gas. Two parts hydrogen to i part carbon dioxid. 
 Produces acid fermentation in milk; coagulates; its optimum 
 temperature for growth is 37° C; causes formation of indol in 
 peptone solutions. In bouillon, forms cloudiness with shmy 
 precipitate. Some cultures non-motile. 
 
THE COLON-TYPHOID GROUP I35 
 
 Growth. — On potato a thick, moist, yellow-colored growth; 
 on agar a gray- white growth; on gelatin a growth similar to 
 typhoid. It can also develop on phenol-gelatin, and with- 
 stands a temperature of 45° C. 
 
 Staining. — Ordinary stains; does not take Gram. 
 
 Pathogenesis. — Inoculated into rabbits or guinea-pigs, 
 death follows in from one to three days, the symptoms being 
 those of diarrhea and coma; after death tumefactions of 
 Peyer's patches and other parts of the intestine; perforations 
 into peritoneal cavity, the blood containing a large number of 
 bacilH. 
 
 The colon bacillus by many writers is held responsible for 
 most of the complications of typhoid fever, such as peri- 
 tonitis, cholangitis, etc. 
 
 Epidemics of a cholera or dysentery nature, called by Esche- 
 rich colitis contagiosa, and due to infection of water and food, 
 have been noted by a number of writers. The onset is very 
 sudden and prostrating, though not fatal. 
 
 Many other forms of suppuration are associated with the 
 presence of Bacillus coh. 
 
 It is supposed to give rise to cystitis, infecting the bladder 
 either through the urethra or the blood. The urine is then 
 acid. 
 
 Distribution. — ^The bacillus has been found very constant in 
 acute peritonitis and in cholera nostras. All normal persons 
 harbor the B. coli in the intestine, where, under ordinary con- 
 ditions, it produces no disturbance. After death it multiplies 
 rapidly, invading the tissues. 
 
 In Water.— Tht presence of B. coli in surface waters is 
 natural, owing to contamination with the fecal discharges of 
 man and other animals. In well-water its presence denotes 
 sewage or surface contamination, and such a well should be 
 condemned until free from coli. (See Water Analysis.) 
 
 Bacillus of Typhoid or Enteric Fever (Eberth-Gafifky). 
 — Origin. — Eberth, in the year 1880, found this bacillus in 
 the spleen and lymphatic glands of persons dying of typhoid, 
 and Gaffky isolated and cultivated the organism four years 
 later. 
 
136 ESSENTIALS OF BACTERIOLOGY 
 
 Form. — Rods with rounded ends about three times as long 
 as they are broad. Usually solitary in tissue-sections, but 
 in old artificial cultures found in long threads. Flagella on 
 all sides (Fig. 58). 
 
 Properties. — Very motile. Spores have not been found; 
 they do not liquefy gelatin. 
 
 Growth. — They are facultative anaerobic; grow best at 37° 
 C, but can also develop at ordinary room temperature. They 
 develop chiefly on the surface, and very slowly. Repeated 
 
 Fig. 58. — Bacillus typhi, from an agar-agar culture six hours old, 
 showing the flagella stained by Loffler's method (Xiooo) (Frankel and 
 Pfeiffer). 
 
 freezing and thawing do not affect the vitality of the germ, 
 and phenol in i to 2 per cent, solution has no effect on it. 
 A ten-minute exposure to 60° C. is invariably fatal. 
 
 Colonies on Gelatin Plates. — Two forms: the ones near the 
 surface spread out like a leaf, transparent, with bluish fluor- 
 escence. The deeper ones resemble whetstone crystals of 
 uric acid, with the same yellowish tinge (Fig. 59). 
 
 In five days they attain to 3 millimeters in diameter. 
 
THE COLON-TYPHOID GROUP 
 
 137 
 
 Bile Salt Media. — Rapid growth without gas formation; a 
 number of special media suited for the growth of typhoid, 
 namely, Jackson's, Hesse, Hiss, Conradi-Drigalski, etc. (See 
 Water Analysis and formula for Media.) 
 
 Stab-cultures. — Mainly on the surface, a pearly layer. 
 
 Agar Stroke Cultures. — A transparent thick layer. 
 
 Potato. — The growth here is quite characteristic. At 37° 
 C. in forty-eight hours a moist, transparent film is formed 
 over the whole surface, but so transparent that it can hardly 
 be seen without close observation. If a small portion of this 
 is placed under a microscope, it will be seen swarming with 
 bacilli (Fig. 60). 
 
 The growth never becomes 
 more prominent; the potato 
 must have a neutral or acid 
 reaction. 
 
 On Potato Gelatin. — The colo- 
 nies do not have the yellow 
 color; they are transparent; 
 later on they become dark 
 brown with green iridescence. 
 
 Milk. — The bacteria grow 
 very well in milk, producing a 
 slightly acid reaction, but no 
 coagulation. 
 
 Fermentation Tube. — In sugar 
 broth, in the fermentation tube, acids are formed without gas. 
 
 Glucose Gelatin. — In glucose gelatin there is no gas-produc- 
 tion. Indol is likewise not generated by the typhoid bacillus, 
 whereas it is by the colon bacillus. 
 
 Staining. — Colored with the ordinary anilin dyes, when 
 they are warmed; since they are easily decolorized, acids 
 should be avoided. Gram negative. 
 
 Distribution. — Outside of the body it is rarely found. 
 Typhoid or enteric fever is a general infection, but affecting 
 chiefly the Peyer's patches of the intestine. The bacilli are 
 found in the intestinal glands and in the enlarged and deeply 
 
 Fig. 59. — Colonies of typhoid 
 bacilli three daj's old (Xioo) 
 (Frankel and Pfeiffer). 
 
138 ESSENTIALS OF BACTERIOLOGY 
 
 congested spleen. Metastatic abscesses form in various parts 
 of the body, and here likemse the organisms abound. They 
 occur in the feces only in small numbers, more commonly in 
 the urine. The urine may contain active bacilli for weeks 
 after recovery from the fever. 
 
 Typhoid Bacilli in Water. — Although all evidence shows 
 that the water-supply is a frequent source of infection, very 
 few persons have ever isolated the typhoid bacillus from such 
 
 Fig. 60. — Bacillus typhosus. Impression preparation from gelatin 
 plate. Fuchsin (Xiooo) (Hicks). 
 
 an infected source. The earlier reports show that no account 
 was taken of Bacillus coli, which is usually present in pol- 
 luted waters. (See Water Analysis.) 
 
 Persistence in PFa/er.— Franckland kept baciUi alive in 
 water, sterilized by heat, seventy-five days; in filtered water 
 at 19° C, five days; at 6° C, twelve days. In ordinary water 
 they are likely to be destroyed in a short time by the over- 
 growth of other bacteria. Under ordinary conditions they 
 do not multiply, but decrease steadily in numbers. In soil 
 
THE COLON-TYPHOID GROUP I39 
 
 they are more persistent. Sewer-gas or air is never a source 
 of infection. 
 
 Mode of Infection. — The bacilU in the dejecta of the dis- 
 eased person find their way into drinking-water, milk, or 
 dirty clothes, and so into the aUmentary tract of a person 
 predisposed to the disease. Flies act as conveyors by infect- 
 ing food. The bacilli enter the blood through the lymphatics, 
 and so become lodged in various organs? They are quite 
 resistant, living for some time in the soil and water, and are 
 more resistant than other organisms to the action of phenol. 
 An epidemic has been traced to the eating of oysters taken 
 from contaminated water. Milk-cans washed in polluted 
 water may be the origin of an epidemic. Ice is rarely a cause. 
 
 Pathogenesis. — Lower animals do not have enteric fever, 
 though their death has been caused by injection of the bacilli 
 into the veins of the ear and peritoneum due to toxic substance. 
 
 In man the bacillus has been found in the urine, blood, spu- 
 tum, milk, intestinal discharges, roseolar spots, and in various 
 organs, as spleen, Uver, lymphatic glands, and intestinal \'ilU. 
 
 It is found in secretions several days after the attack has 
 subsided. It is found in this disease only. 
 
 Typhoid Carriers. — Some individuals retain a culture of 
 the bacilli in the gall-bladder for years, and manufacture, or 
 at least expel, true virulent bacilH through the feces and urine 
 intermittently. Such persons have infected other individuals 
 without suffering any inconvenience themselves. Some 
 forms of chronic inflammation, as cholecystitis and appen- 
 dicitis, have been caused by the typhoid bacillus, though 
 more often the colon bacillus is found. 
 
 Products. — Brieger found a substance in the cultures, 
 which he named typhotoxin, with the formula C9H17NO2. 
 It has no specific action. A toxalbumin insoluble in water has 
 also been isolated, but, as experiment animals are immune to 
 the disease, no definite actions have yet been determined. 
 
 The cultures, when old, show an acid reaction. 
 
 Antityphoid bacterins (vaccines) have been used very ex- 
 tensively in armies and institutions as a prophylactic or pro- 
 
I40 ESSENTIALS OF BACTERIOLOGY 
 
 tective. Bacterins are made from a weakly virulent culture. 
 The results so far obtained would indicate that this inocula- 
 tion has some value, but the evidence is far from conclusive 
 and the statistics on the subject require more careful study 
 before they can be accepted as positive proof. An eighteen- 
 hour agar surface growth is w^ashed in sterile salt solution 
 and killed by heating at 56° C. one hour. It is then diluted 
 so as to contain one biUion bacilli to i c.c. Tricresol, 0.25 per 
 cent., is added to preserve, and animals tested for purity of the 
 vaccine. A slight local reaction follows the inoculation; 
 about three injections of >^, i, and one billion bacilli at ten- 
 day intervals, render the subject immune. General symp- 
 toms rarely occur. 
 
 The Gruher-Widal Blood- serum Test. — In 1896 Widal and 
 Griinbaum, working separately, developed what is now spoken 
 of as the ''Widal serum test," or ^^ Widal reaction,''' or aggluti- 
 nation test. It consists in testing a drop of blood of a patient 
 suspected of having typhoid fever, by mixing a dilution of 
 it with a drop of a fresh bouillon culture of typhoid bacilli, 
 and examining the mixture in a hanging drop under the 
 microscope. Within fifteen minutes to an hour the motility 
 of the bacilli will cease, and they will have arranged them- 
 selves into clusters, as if stuck or glued together (Fig. 61). 
 If this reaction occurs within an hour, and with the proper . 
 dilution of the serum, the patient has or has had typhoid 
 fever. Widal first used the serum of the blood; this has 
 been modified so that a drop of dried blood is sufficient. 
 
 Method of Test. — The method as applied in city laboratories 
 is as follows: The physician is told to clean the finger of the 
 patient with water (no germicides) , and with a needle draw a 
 drop of blood on to a piece of ordinary note-paper. This is - 
 then sent to the laboratory; the paper with the dried blood 
 is soaked for a few minutes in a watch-glass containing 4 
 drops of clean water, thus obtaining a dilution of i 15. One 
 drop of this is then mixed with one drop of a bouillon culture 
 of typhoid bacilli of about twenty-four-hours' growth, and 
 examined under the microscope in the hanging drop. Weaker 
 
THE COLON-TYPHOID GROUP I4I 
 
 dilutions of the serum have been recommended (i : 50), and 
 this should be used in cases of doubt. So far, about 95 per 
 cent, of the cases examined, and which clinically were con- 
 sidered typhoid fever, have given a positive reaction. It is 
 not often present until the fifth day of the fever, and dis- 
 appears usually within a year, though in some individuals it 
 has been found ten years after an attack of the disease. 
 
 The agglutinating properties have been found in nearly all 
 the secretions of the body — tears, urine, milk, pleuritic effu- 
 sions serous fluid from blisters, etc. 
 
 Fig. 61. — The Widai agglutination reaction (Slater and Spitta). 
 
 There is no relation between the reaction and the bacteri- 
 cidal power of the serum; the agglutination is not a destruc- 
 tion. The agglutinating power is active, though the blood be 
 dried and sealed up for months. It seems to have no direct 
 relation with the question of immunity, since it occurs at the 
 height of the disease, and intense agglutinating serum may 
 be had in severe cases and in cases with relapses. A negative 
 result does not exclude typhoid. 
 
 The test is quantitative — i. e., it depends upon the dilution 
 of the blood-serum, since the serum of healthy persons in 
 strong dilution will cause agglutination and loss of motility. 
 
142 ESSENTIALS OF BACTERIOLOGY 
 
 A serum in a dilution of i : loo causing complete clumping 
 in half an hour is undoubtedly typhoid. 
 
 The culture must be kept in a vigorous condition by fre- 
 quent subplanting, and must be tested occasionally with 
 normal serum. Cultures kept in an incubator for a long time 
 tend to agglutinate spontaneously. 
 
 Macroscopic Agglutination Test. — Where laboratory facili- 
 ties are not available, the sedimentation test is practical. 
 It consists in adding the diluted blood or serum to be tested 
 to a suspension of dead typhoid bacilli in salt solution. If 
 the reaction is positive, a flocculent precipitate forms which 
 consists of masses of agglutinated bacilli. A control tube con- 
 taining normal serum and the suspension should remain 
 opaque and show no flocculi. 
 
 Differentiation Between Colon and Tjrphoid. — The 
 colon bacillus and the typhoid bacillus resemble each other 
 so closely that much attention has been paid to methods of 
 differentiation. 
 
 Points of Resemblance Between Bacillus Typhi and Bacillus 
 Coli Communis. — First, microscopic appearance; second, agar 
 and gelatin cultures; third, sometimes growth on potato the 
 same; fourth, staining peculiarities; fifth, resistance to phenol. 
 
 Points of Difference: 
 
 Colon Bacillus. Typhoid Bacillus. 
 
 Bile media, gas. None. 
 
 Less motile. Actively motile. 
 
 Gelatin colonies develop Develop slowly. 
 
 more rapidly. 
 
 Produces gas on dextrose or Does not. 
 
 lactose media. 
 
 Coagulates milk. Does not. 
 
 Produces indol. Does not. 
 
 Growth on potato visible. Invisible. 
 
 Changes neutral red to Does not reduce neutral red. 
 
 yellow. 
 
 Endo-fuchsin red. Not. 
 
THE COLON-TYPHOID GROUP I43 
 
 Differences are also noted in the growth on special media, 
 such as those of Hiss and Eisner. On Eisner's potato-gelatin 
 the colon bacillus and the typhoid bacillus both grow read- 
 ily. The medium of Hiss is of some assistance in isolating 
 the germ. (See p. 75.) 
 
 Hiss Media. — Show^s B. colt, large colony, even borders. 
 B. typhi, small colony, hairy and fringy threads. (See p. 75.) 
 
 Endo-fuchsin-lactose Agar (see p. 77). — Incubation on 
 plates of this media shows B. coli red; typhoid as clear, color- 
 less drops. 
 
 Malachite green added to agar permits the growth of B, 
 typhi, but not B. coli. The dye must be as nearly neutral as 
 possible. 
 
 Bile Salt Media. — Fresh bile or sodium taurocholate added 
 to lactose glucose agar or broth permits the rapid growth of 
 both B. typhi and B. coli, fermentation with gas formation 
 denoting B. coli, growth without fermentation meaning 
 typhoid. 
 
 Drigalski and Conradi Media. — Petri plates filled with 
 this media are inoculated on the surface only. Placed in 
 incubator sixteen to twenty-four hours. Typhoid colonies 
 small, transparent, and blue. Colon colonies red, coarser, 
 and larger. 
 
 Typhoid Bacilli from Blood. — Conradi, Busquet, Coleman 
 and Buxton, and others have found the bacilli in the blood of 
 every patient by the following method: A mixture of ox-bile, 
 90 c.c, glycerin, 10 c.c, and peptone, 2 gm., is distributed 
 into 20 c.c. flasks and sterilized. Ten cubic centimeters of 
 blood is drawn from the elbow into a glass syringe and divided 
 among three flasks. These are incubated, and in twenty-four 
 hours litmus-lactose- agar plates are inoculated on the surface 
 by a stroke from the flasks. A growth is obtained in five or 
 six hours. 
 
 If the growth is a bacillus which has not reddened the 
 medium, it is tested for the Widal reaction with immune se- 
 rum. The diagnosis has been made as early as the second day. 
 
 Paracolon or paratyphoid bacilli are members of the 
 
144 ESSENTIALS OF BACTERIOLOGY 
 
 colon group described by Widal, Gwyn, Schottmliller, and 
 others. They are of importance, since they produce fevers 
 clinically resembling a mild form of typhoid, but which are 
 rarely fatal. They may be the sole cause of the disease, and 
 also occur together with the typhoid bacillus in mixed arid 
 secondary infections. Morphologically, they resemble the 
 typhoid bacillus, but differ from it culturally and give their 
 own serum reactions with the blood of affected patients. 
 They ferment glucose, but not lactose or saccharose; litmus 
 milk at first becomes acid, but later grows alkaline and is not 
 
 Fig. 62. — Bacillus botulinus, with spores. Pure culture on sugar- 
 gelatin. Van Ermengem prep. (Kolle and Wassermann) . 
 
 coagulated. On potato a slight visible growth occurs; in- 
 dol is usually not formed. Typhoid sera do not agglutinate 
 paracolon bacilli, and vice versa; also different paracolon 
 infections may not agglutinate each other. 
 
 Bacillus Botulinus (Van Ermengem). — An anaerobic ba- 
 cillus cultivated by Van Ermengem in 1896 from ham which 
 had caused poisoning. 
 
 Form. — A large bacillus with rounded or spindle-shaped 
 ends, and often with oval terminal spores, motile, with lateral 
 flagella (Fig. 62). 
 
THE COLON-TYPHOID GROUP I45 
 
 Staining. — Gram positive, easily stained with ordinary 
 dyes. 
 
 Growth. — Strictly anaerobic. Forms abundant gas in glu- 
 cose, gelatin, and liquefies cultures, producing butyric acid 
 odor. Best temperature between 20° and 30° C. 
 
 Pathogenesis. — Produces a powerful toxin in the tissues, 
 like the tetanus bacillus. This toxin may be present in the 
 affected meat without causing decomposition, and thus give 
 rise to poisoning. 
 
 Bacillus Dysenteriae (Shiga, 1898). — The term dysen- 
 tery is applied to an intestinal disease displaying more or less 
 
 Fig. 63. — Bacillus dysenteriae from agar culture. Fuchsin stain. Zett- 
 novv prep. (KoUe and Wassermann) . 
 
 constancy in its clinical manifestations, but having, as is now 
 known, a variety of causative agents. It is fairly certain that 
 one type is the result of infection with an ameba, while non- 
 amebic forms can probably be produced by several bacteria. 
 Chief among these is the bacillus first described by Shiga in 
 Japan, and since then found by Kruse in Germany, by Flex- 
 ner, Strong, and Harvie in the Philippine Islands, and by 
 Vedder and Duval in the United States. The fact that it is 
 constantly present in the feces in one type of dysentery, that 
 
146 ESSENTIALS OF BACTERIOLOGY 
 
 such cases give a positive agglutination reaction, the produc- 
 tion of a curative serum by the immunization of animals 
 with pure cultures, and the results on experiment animals, 
 leave little doubt as to the specificity of the organism. 
 
 Origin. — The dejecta of dysenteric patients. 
 
 Form. — ^A plump bacillus with rounded ends, resembling 
 the typhoid and colon bacilli (Fig. 63). 
 
 Properties. — Motility doubtful, but numerous flagella have 
 been demonstrated. Does not form spores. 
 
 Staining. — Stains readily, negative to Gram; facultative 
 anaerobe. 
 
 Growth. — Best at 37° C. Killed by ten minutes' exposure 
 to 55° C. 
 
 Gelatin. — ^A white line of growth along puncture; super- 
 ficial growth slight. 
 
 Bouillon. — Uniform clouding. Indol usually not produced; 
 milk not coagulated. 
 
 Agar. — Resembles typhoid bacillus. 
 
 Potato. — Thin whitish layer, turning light brown. 
 
 No gas-formation in glucose or lactose media. 
 
 Acid is formed. 
 
 Pathogenesis. — Mice and guinea-pigs die in one or two days 
 after intraperitoneal inoculation. Rabbits usually recover, 
 though lesions analogous to those of human dysentery have 
 been produced. Dogs die in five or six days, with well- 
 marked diarrhea. 
 
 Products. — The patient's blood-serum agglutinates the ba- 
 cillus in cases in which it can be cultivated from the stools. 
 The reaction is absent from other cases. Shiga has reduced 
 the mortality from 34.7 to 19 per cent, by means of a serum 
 obtained from immunized horses, but in more extensive tests 
 the antidysenteric serum proved of little value. 
 
 In man the organism or some of its varieties is associated 
 with dysentery and is found chiefly in the stools; abscesses 
 are seldom found; the amebic dysentery forms liver abscess, 
 not in other organs. Polluted water is responsible for its 
 spread in epidemic form. 
 
THE COLON-TYPHOID GROUP I47 
 
 In the summer diarrhea of infants associated with mucus, 
 B. dysenterice has been found, and is considered a causative 
 agent. 
 
 Bacterium Termo (Cohn). — This was a name given to a 
 form of microorganism found in decomposing albuminous 
 material, and was supposed to be one specific germ. Hauser, 
 in 1885, found three different distinct bacilli which he grouped 
 under the common name of proteus, which have the putrefy- 
 ing properties ascribed to Bacillus termo. 
 
 Bacillus Proteus Vulgaris (Hauser, 1885). — Origin. — 
 In putrid animal matter, in the feces, and in water. 
 
 Form. — Small rods, slightly curved, of varying lengths, 
 often in twisted chains, having long cilia or flagella. 
 
 Properties. — Very motile, and very soon liquefying gelatin; 
 forms hydrogen sulphid gas; causes putrefaction in meat. 
 
 Growth. — Growth very rapid, best at 24° C; is facultative 
 aerobic. 
 
 Gelatin Plates. — Yellowish-brown, irregular colonies, with 
 prolongations in every direction, forming all sorts of figures; 
 an impression preparation shows these spider-leg processes to 
 consist of bacilli in regular order. 
 
 Stab-culture. — The gelatin soon liquid, a gray layer on the 
 surface, but the chief part of the culture in small crumbs at 
 the bottom. 
 
 Agar. — Rapid, moist, gray growth. 
 
 Milk. — Acid coagulation. 
 
 Dextrose Broth. — Gas-production. 
 
 Pathogenesis. — Rabbits and guinea-pigs injected subcutane- 
 ously die quickly; a form of toxemia, hemorrhagic condition 
 of lungs and intestines, present. When neurin is injected 
 previously, the animals do not die. This ptomain is sup- 
 posed to be generated by the Proteus vulgaris. 
 
 In man these or similar bacteria have been associated with 
 food-poisoning epidemics, infantile diarrhea, infectious jaun- 
 dice (Weil's disease). 
 
 Proteus Mirabilis (Hauser). — Differs from Proteus vul- 
 
148 ESSENTIALS OF BACTERIOLOGY 
 
 garis in that the gelatin is less rapidly liquefied. Found also 
 in putrid material. 
 
 Proteus Zenker! (Hauser). — Does not liquefy gelatin: 
 otherwise similar to the other two. 
 
 CHAPTER XXI 
 
 CHOLERA BACTERIA 
 
 Spirillum Cholerae (Koch) (Comma Bacillus of Chol- 
 era) . — Synonym, Vibrio CholercB. — Origin. — Koch, as a mem- 
 ber of the German expedition sent to India in 1883 to 
 ,^^ ^^ study cholera, found this micro- 
 
 '^•i^^^^^^^ organism in the intestinal contents 
 
 l^^^^j^^ ^^/^^S^ of cholera patients, and by further 
 Jt»'^&^^''\^^% A experiments identified it with the 
 ^^ "^^-v^^^'^*-^ disease. 
 
 *^^f\ mS^^^tT- Fortn. — ^The spirillum as seen or-, 
 
 '^^^^t'i^^'^^^ ' dinarily appears as a shorty arc-like 
 ^"'" ' '■"^ body, about half the size of a tuber- 
 
 Fig. 64.— Comma bacillus, cle bacillus, but when seen in large 
 pure culture (X 600). groups, spirals are formed, each little 
 arc appearing then as but a segment, 
 a vibrio. Each arc is about three times as long as it is broad, 
 and possesses a flagellum at one end. Old agar cultures show 
 straight forms; S-shaped forms not uncommon, made of two 
 vibrios end to end (Fig. 64). 
 
 Properties. — The spirilla are very motile; liquefy gelatin. 
 They are easily affected by heat and dryness. Spores have 
 not been found. 
 
 Growth. — ^At ordinary temperatures on all nutrient media 
 
 that have an alkaline or neutral reaction. Strongly aerobic. 
 
 Colonies, Gelatin. — After twenty-four hours, small w^hite 
 
 points which gradually come to the surface, the gelatin being 
 
CHOLERA BACTERIA 
 
 149 
 
 slowly liquefied, a funnel-shaped cavity formed, holding the 
 colony in its narrow part, at the bottom, and on the fifth day 
 all the gelatin is liquid. If the colonies of three days' growth 
 are placed under microscope, they appear as if composed of 
 small bits of frosted glass with sharp, irregular points. 
 
 Stab-culture. — After thirty hours a growth can be distin- 
 guished along the needle- track, and on the surface a little 
 cavity is formed, filled by a bubble of air, and this liquefaction 
 
 Fig. 65. — Cholera colonies after thirty hours (Xioo) (Frankel and 
 
 Pfeiffer). 
 
 proceeds until, on the sixth day, it has reached the sides of 
 the tube, tapering, funnel-shaped, to the bottom of the tube. 
 After several weeks the spirilla are found in little collections 
 at the bottom of the fluid gelatin. In eight weeks the bacilli 
 have perished. 
 
 Agar. — Stroke cultures. A shiny white layer which lasts 
 many months. 
 
 Alkaline Agar. — Plates at 37° C. Flat discs, transparent, 
 grayish blue. 
 
ISO 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Potato. — A yellow, honey-like, transparent layer if the 
 potato is kept at animal heat. 
 
 Bouillon. — A wrinkled scum is soon formed in bouillon. 
 The spirilla live well and grow in sterilized milk and sterilized 
 water, remaining virulent in the latter for many months. 
 
 Fig. 66. — Cholera 
 bacillus (forty-eight 
 hours; 5 per cent, 
 gelatin). 
 
 Fig. 67. — Cholera 
 bacillus (sixty hours; 
 5 per cent, gelatin). 
 
 Fig. 68.— Cholera 
 bacillus (seventy- 
 two hours; 15 per 
 cent, gelatin). 
 
 Figs. 66-68. — Tube-cultures (from United States Government Report 
 on Cholera. — Shakespeare) . 
 
 In ordinary water the bacteria present are destructive to the 
 comma bacilli, and they die in a few days. 
 
 Dunham^ s Peptone Solution. — Useful for the development of 
 nitrites and the indol reaction. (See p. 77.) Also for the 
 rapid development of the cholera vibrio. In four hours after 
 inoculation of peptone water pure cultures may be obtained; 
 
CHOLERA BACTERIA 15I 
 
 best to make several plantings from the peptone to agar after 
 six hours' growth. 
 
 Dieudonne's Medium. — (See p. 77.) In this cholera vibrio 
 grow abundantly; other intestinal bacteria very scantily. 
 This medium valuable mostly for feces, less for infected water. 
 
 Staining. — They are colored well with watery anilin solu- 
 tions. The fiagella can be well seen by staining according to 
 the fiagella stain or Giemsa. 
 
 Pathogenesis. — Experiment animals are not subject to 
 cholera Asiatica, but, by overcoming two obstacles, Koch 
 produced choleraic symptoms in guinea-pigs. Nicati and 
 Rietsch prevented peristalsis and avoided the acidity of the 
 stomach-juices by direct injection into the duodenum, after 
 tying the gall-duct. Koch alkalinized the gastric juice with 
 5 c.c. of 5 per cent, solution of sodium carbonate, and then 
 injected 2 grams of opium tincture for every 300 grams of 
 weight into the peritoneal cavity, paralyzing peristalsis. The 
 cholera culture then introduced through a stomach-tube, the 
 animals die in forty-eight hours, presenting the same symp- 
 toms in the appearance of the intestines as in man, the serous 
 effusion containing great numbers of spirilla. Rabbits in- 
 jected into the ear veins with cholera cultures die very quickly 
 and present intestinal lesions. The vibrio is met with in the 
 layer of flaky mucus which coats the surface of the intestine. 
 
 It may invade the biliary passages. 
 
 Manner of Infection in Man. — Usually through the alimen- 
 tary tract, with the food or drink, the intestinal discharges of 
 cholera patients having found entrance into the source of 
 drinking-water. Soiled clothes to fingers, fingers to the 
 mouth, etc.; torpid catarrhal affection of the digestive tract 
 predisposing. The spirilla are not foimd in the blood or any 
 organ other than the intestines — the tissue of the small intes- 
 tines. They are also found in the vomit and the intestinal 
 contents. 
 
 Toxins. — From broth cultures soluble toxins which have a 
 hemolytic action have been isolated. The toxin is easily 
 destroyed by heat (thermolabile). 
 
152 ESSENTIALS OF BACTERIOLOGY 
 
 Products — ^^ Cholera red.^' Indol Reaction. — Present in 
 peptone water cultures containing nitrates. The indol is 
 shown by the addition of a few drops of pure sulphuric acid, 
 the solution turning red — the so-called ^'cholera red.'' Once 
 thought distinctive, but other bacteria also give rise to indol, 
 and the same reaction. 
 
 Serum Agglutination Test. — The agglutination test is made 
 in the same way as the Widal test for typhoid fever. Ag- 
 glutinins appear in the blood five to ten days after infection. 
 
 
 Fig. 67. — Comma bacillus in mucus, from a case of Asiatic cholera. 
 
 Cultures in serum dilutions of 1:1000 up to 1:10,000 are 
 agglutinated. 
 
 Detection of Cholera Organisms in Drinking-water. — ^When 
 a few bacteria are supposed to be present in fecal matter or 
 drinking-water, it is best to add a large quantity of the ma- 
 terial (200 c.c. of drinking-water) to about 10 c.c. of bouillon 
 or peptone-water, and place the mixture for twenty-four hours 
 in an incubator, which will cause rapid reproduction, and then 
 the organisms can be readily discovered. 
 
CHOLERA BACTERIA 1 53 
 
 From Feces. — The following technic is recommended: 
 
 1. Examine mucous flakes in stained preparations and 
 hanging drop. 
 
 2. Isolate on agar media at 37° C. 
 
 (a) Plant plates of alkalinized agar and Dieudonne's 
 medium with particles of feces. 
 
 (b) Plant in 50 c.c. peptone solution i c.c. fecal matter. 
 After six hours or longer in the incubator at 37° C. 
 take several loopsful from the surface and plant on 
 several plates Dieudonne's and ordinary alkaline agar. 
 
 (c) Investigate agglutination reaction, using drops from 
 
 isolated colonies and secure pure cultures. 
 
 3. Demonstrate the reaction of Pfeiffer and agglutination 
 with the pure colonies. 
 
 Protective Bacterins. — ^Virulent cultures killed by heat have 
 shown protective power and were used extensively during an 
 epidemic in Japan. 
 
 Haffkine has obtained a great reduction in mortality in 
 cholera regions by the use of anticholera bacterins as a pro- 
 tective measure. 
 
 Serum therapy has not been successful. 
 
 Carriers. — In some recent examinations of persons exposed 
 to cholera, carriers of typical cholera vibrio have been found. 
 The vibrio may be found, as in typhoid fever, in the gall- 
 bladder. 
 
 Pfeifer^s Reaction and Agglutination. — The serum of an 
 animal (a rabbit) made iromune against cholera by the in- 
 jection of sterile or living cultures, intravenously, three times 
 at intervals of a week, has an action against the cholera spiril- 
 lum. It first precipitates the bacteria out of an emulsion, leav- 
 ing a clear liquid (agglutination), and then dissolves the bac- 
 teria (bacteriolytic action), leaving only spheric granules. 
 This action is specific, i. e., the cholera immune sera will 
 affect only cholera vibrio. Such serum is not antitoxic, it 
 is bacteriolytic. For diagnostic purposes an agglutination 
 in dilution of i : 1000 by a serum with an activity of i : 4000 
 is suspicious of cholera. The blood-serum of convalescents 
 
154 ESSENTIALS OF BACTERIOLOGY 
 
 and cholera-vaccinated individuals contains the same bac- 
 tericidal substances. 
 
 Allied Varieties. — Many vibrios resembling the spirillum of 
 cholera have been isolated from drinking-waters and from 
 the stools of persons suffering with diarrhea, and some bac- 
 teriologists are inclined to consider them as varieties of the 
 true cholera spirillum, which under certain conditions become 
 pathogenic. Among these are Spirillum berolinense, S. dun- 
 barii, S. danubicum, S. of Wernicke, S. bonhoffii, S. weibeH, S. 
 schuylkilliensis, S. milleri, S. aquatilis. The last two are 
 non-pathogenic for experiment animals, also the Finkler- 
 Prior vibrio, \dbrio Metchnikovii, and tyrogenum, which have 
 historic interest because of their close identity with the 
 cholera organism, but with the agglutination tests and 
 Pfeiffer phenomenon they have been shown to be dissimilar. 
 
 Conclusions of International Committee of Public Hygiene, 
 Adopted October p, igii. — Every choleriform vibrio can be 
 considered as truly choleraic which presents agglutination in 
 the proportion of at least i:iooo by a cholera serum of 
 1:4000 activity, or a positive Pfeiffer reaction, and every 
 choleriform affection in which is encountered such a vibrio 
 should be considered as a case of cholera. 
 
 Method of Pfeifer. — i. Secure immune serum by injecting 
 into peritoneal cavity of a rabbit an entire agar culture which 
 has been killed by heating for one hour at 56° C. Four- 
 teen days after collect the blood-serum. 
 
 2. Dilute the suspected vibrio by adding one loopful of an 
 eighteen-hour-old agar culture to i c.c. meat water. 
 
 3. Add to the above about i milligram of immune serum 
 and inject this into peritoneal cavity of a guinea-pig. 
 
 4. At the same time a second guinea-pig is inoculated with 
 diluted culture (2), but without the serum. 
 
 5. A third guinea-pig is inoculated with a similar dilution 
 of culture to which has been added about 10 milligrams 
 normal rabbit serum. 
 
 6. At the end of twenty minutes, and again at the end of 
 one hour, some of the peritoneal fluid is examined from each 
 
BACTERIA IN PNEUMONIA 15$ 
 
 pig, under strong magnification, in hanging drop and dark 
 field illumination. 
 
 7. The reaction is positive if iii the fluid from No. i pig 
 the vibrios are dissolved, while in that from No. 2 arid No. 3 
 the vibrios are very motile and active and form well pre- 
 served. 
 
 It is necessary that the vibrio be of good virulence. 
 
 Method of Bordet. — As experiment animals are not always 
 available, Bordet has elaborated a test-tube method. The 
 immune serum is diluted 1:50, 1:100, 1:500, and 1:1000. 
 Into a series of test-tubes there are poured 5 drops of a guinea- 
 pig serum, 5 drops of a mixture of suspected culture (one loop- 
 ful of an eighteen-hour-old agar culture to i c.c. salt solution), 
 and enough of immune serum and salt solution to make the 
 necessary dilution and up to 20 drops. A series of controls 
 is made with normal serum and the same amount of microbic 
 culture and guinea-pig serum. 
 
 After eighteen hours the cholera vibrios will be active in the 
 control, but dissolved and clumped up in the tubes containing 
 the immune serum. 
 
 CHAPTER XXII 
 BACTERIA IN PNEUMONIA 
 
 Klebs in 1875 called attention to the presence of bacteria in 
 pneumonia, and in 1882 Friedlander developed a bacillus from 
 the lung tissue of a pneumonic person which he thought was 
 a coccus, and called it pneumococcus. 
 
 In 1886 A. Frankel and Weichselbaum proved that this 
 organism was not constant — in fact, was rare. 
 
 A. Frankel obtained in the majority of cases of pneumonia 
 an organism that he had described in 1884 under the name 
 of sputum-septicemia micrococcus. 
 
 Weichselbaum called this Diplococcus pneumonic^, and be- 
 
156 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Fig. 70. — Bacillus pneumuniic ui 1- nediaiKler, from the expectoration of a 
 pneumonia patient (Xiooo) (Frankel and Pfeiffer). 
 
 m 
 
 •* • 
 
 V 
 
 Fig. 71. — Diplococcus pneumonias in exudate from human lung; anilin- 
 water-fuchsin; Weichselbaum prep. (Kolle and Wassermann). 
 
BACTERIA IN PNEUMONIA 
 
 157 
 
 lieved it to be the real cause of pneumonia. It is the generally 
 accepted organism of the disease, and can be isolated from 
 nearly all cases of acute croupous pneumonia. It is found in 
 about three-quarters of all cases of pneumonia. 
 
 Diplococcus Pneumoniae (Frankel and Weichselbaum, 
 1 886) . — Synonyms. — Streptococcus Lanceolatus; Pnemno coccus; 
 Diplococcus Lanceolatus; M. of Sputum Septicemia; Fr ankers 
 Fneumococcus. 
 
 Origin. — Found it in the sputum of pneumonic patients. 
 It has been found in many other serous inflammations, and 
 also in the mouths of healthy persons. 
 
 Fig. 
 
 72. — Diplococcus of pneumonia in blood of rabbit (Xiooo) 
 (Frankel and Pfeiffer). 
 
 Form. — ^Large, lancet-shaped cocci. Usually found in 
 pairs, sometimes in filaments of three and four elements. In 
 the material from the body a capsule surrounds each coccus. 
 In the artificial cultures this is not found (Figs. 71 and 72). 
 
 Froperties. — Variable in form, approaching the bacillary 
 type. Do not liquefy gelatin. There are no spores. Non- 
 motile. 
 
 Growth. — Best between 27° C. and 41° C, seldom below 
 25° C. Facultative anaerobic. The culture-media must be 
 slightly alkaline; the growth is slow. 
 
158 ESSENTIALS OF BACTERIOLOGY 
 
 Colonies. — Glucose or Glycerin Agar Plates. — Growth slow, 
 of small, round, moist colonies, separated. 
 
 Stab-cultures. — Along the needle-track small separate white 
 granules, one above the other, like a string of beads. 
 
 Blood Bouillon. — Bouillon containing one-third blood-serum 
 or ascitic fluid favors the growth. They grow better here than 
 in the other media, remaining alive a longer period of time. 
 
 Blood-serum or Blood-agar. — Growth more vigorous. A 
 good growth on blood-serum or blood-agar. 
 
 Fig. 73. — Pneumobacillus in blood (Xiooo) (Frankel and Pfeiffer). 
 
 Staining. — Takes Gram's method and the other anilin 
 stains very readily. The capsule stained by Hiss method 
 (p. 61) or Welch. 
 
 Resistance. — Cultures in sugar media must be frequently 
 transplanted, as the organism is destroyed in a few days by 
 the acid generated. In albumin alkaline media (blood-serum, 
 etc.) the cultures can be kept active two weeks or more. In 
 sputum the pneumococcus may survive several days. When 
 dried but exposed to sunlight, death occurs in a few hours. 
 
BACTERIA IN PNEUMONIA 1 59 
 
 Pathogenesis. — Rabbits and guinea-pigs, if subcutaneously 
 injected, die in the course of a couple of days with septicemia 
 (o.i ex. of a fresh bouillon culture suffices). 
 
 Autopsy shows greatly enlarged spleen and myriads of 
 micrococci in the blood and viscera, the lungs not especially 
 affected. If injected into the trachea, a pneumonia occurs. 
 In man they are found in 90 per cent, of croupous pneumonia, 
 and usually only during the existence of the rusty sputimi, 
 i. €., the first stage. Found in the tissue of the inflamed 
 lung, and in the blood in nearly all cases of lobar pneumonia. 
 
 The pneumococcus has also been found in pleuritis, peri- 
 tonitis, pericarditis, meningitis, and endocarditis. It stands 
 in some intimate relation to all infectious inflammations of 
 the body. Their presence in healthy mouth secretion does 
 not speak against this, it requiring some slight injury or low- 
 ered resistance to allow this ever-present germ to produce a 
 pneumonia from an infectious disease like measles or in- 
 fluenza. 
 
 Toxins and antitoxins have not been separated or demon- 
 strated. The poisons are probably endotoxins, and closely 
 connected with the cell-body. Agglutination properties of 
 pneumonia blood serum, if any, are very weak — i : 50. 
 
 Immunity and Serum Therapy. — One attack produces no 
 immunity; and no immune serum has been found of any value. 
 By growing in an acid medium, the organism has been ren- 
 dered less virulent. 
 
 Bacillus Pneumoniae (Friedlander, 1882). — Synonym. — 
 Capsule Bacillus of Pfeifer. — Once supposed to be a cause of 
 pneumonia. It grows readily on ordinary media; is Gram 
 negative; in form and capsule formation it sometimes re- 
 sembles the pneumococcus (Fig. 70). 
 
 Bacillus of Rhino scleroma (Frisch, 1882). — It was found 
 in the tissue of a rhinoscleroma, but resembles the Fried- 
 lander bacillus in nearly every respect, and as the disease 
 rhinoscleroma is not reproduced by the inoculation of the 
 bacillus in animals, it can be considered identical. The 
 
l6o ESSENTIALS OF BACTERIOLOGY 
 
 growth, cultures, and properties are the same as the pneumo- 
 bacillus of Friedlander. 
 
 Bacillus of Influenza (Pfeiffer, 1892). — Origin. — One of 
 the smallest of the known bacilli, 1.5 ^u by 0.3 /z, about one- 
 half the size of the bacillus of mouse septicemia, and ar- 
 ranged in chain form. It develops upon blood-serum agar. 
 It is aerobic, without movement (Fig. 74). 
 
 Stain. — It is best stained with diluted carbol-fuchsin, the 
 
 .1* 
 
 
 .* "vV 
 
 *K' 
 
 
 % 
 
 -.?*. 
 
 
 
 Fig. 74. — Bacillus influenzae, from a gelatin culture (Xiooo) (Itzerott 
 and Niemann). 
 
 contrast-Stain being Loffler's methylene-blue ; does not take 
 the Gram stain. 
 
 Growth. — Upon blood-agar or glycerin-agar, over which a 
 drop of blood has been spread, in an incubator at 37° C. at 
 the end of twenty-four hours a very delicate growth occurs 
 which resembles condensed moisture. Very small colonies, 
 never larger than a pinhead, feebly resistant. Subcultures 
 must be made every few days. 
 
 Pathogenesis. — It is found in the sputum and in the bron- 
 chial and nasal secretions and blood of influenza patients. It 
 
BACTERIA IN PNEUMONIA l6l 
 
 has been transmitted to monkeys; other animals are not suscep- 
 tible. It has never been found outside the body. Its resistance 
 is very feeble ; in water, the bacilli die in twenty-four hours, 
 but sputa containing the germs may be ejected for days and 
 weeks. Influenza bacilli are found accompanying broncho- 
 pneumonia, tuberculosis, meningitis, and other inflammations. 
 The bacillus is found in healthy individuals, to a consider- 
 able extent in the nasal secretions, and it is probably spread in 
 the fine droplets of mucus expelled in sneezing and coughing. 
 
 Koch-Weeks Bacillus (1883-87) .—Cause of epidemic 
 conjunctivitis, or ''pink eye"; found in the secretion. 
 
 Form. — ^Very minute bacillus, resembling the influenza 
 bacillus; non-motile. (See Fig. 84, p. 173.) 
 
 Growth. — They grow best on blood-serum agar, but very 
 sparsely in minute transparent colonies; non-liquefying. 
 
 Stains. — With carbolfuchsin, and is often intracellular. 
 Does not take Gram. 
 
 Pathogenesis, — Very contagious, found in 10 per cent, to 20 
 per cent, of all cases of conjunctivitis. Not infectious for 
 lower animals, and not causing any other form of disease. 
 
 Bacillus of Pertussis (Whooping-cough) (Bordet- 
 Gengou, 1906). — It has been shown that very minute 
 bacilli resembling the influenza bacillus occur in the cilia of 
 the cells lining the trachea and bronchi of persons affected 
 with whooping-cough ; these bacilli interfere with the normal 
 movement of the cilia, and cause an irritation producing 
 symptoms peculiar to the disease. 
 
 Morphology. — Very minute bacilli with rounded ends 
 (Fig. 75). 
 
 Cultures. — On potato-blood-agar, after twenty-four hours, 
 slight growth, sticky, grayish; subcultures made on blood- 
 serum and veal-agar grow readily. 
 
 Staining. — Gram-negative, stain lightly with ordinary dyes. 
 
 Pathogenesis. — By inhalation inoculation young rabbits 
 were made to develop a spasmodic cough, and the bacillus 
 was recovered from the trachea and from bronchi in pure cul- 
 tures. In the sputum of persons affected with whooping- 
 
l62 ESSENTIALS OF BACTERIOLOGY 
 
 cough the bacillus is found in large numbers. The recent 
 work of Mallory, Henderson, and Horner (Jour. Med. Re- 
 search, March, 19 13) seems to establish this organism as the 
 real cause of pertussis. 
 
 Bacterins made from the culture have been recommended 
 to allay the spasmodic cough. 
 
 Bacillus Melitensis (Bruce, 1887). — Synonym. — Micro- 
 coccus Melitensis. — Malta fever, also known as Mediterra- 
 nean fever, occurs in the region from which it derives its 
 
 /•-" 
 
 Fig. 75- — The Bordet-Gengou bacillus of whooping-cough. Twenty-four- 
 hour-old culture upon solid media containing blood (Bordet-Gengou). 
 
 name, but has been observed in India, the Philippine Islands, 
 and Porto Rico. Bruce cultivated an organism from the 
 spleen and proved its specificity. 
 
 Origin. — Is found most abundantly in the spleen. 
 
 Form. — Rounded or oval, very small, coccus-like bacilli, 
 0.5 jLt in diameter, singly, in pairs, or short chains. 
 
 Properties. — Non-motile, though flagella said to be present; 
 grows slowly, best at body-temperature. 
 
 Gelatin. — Not liquefied; growth very slow. 
 
PYOGENIC coca 163 
 
 Bouillon. — Turbid, with sediment. 
 
 Agar. — Pearly white growths. 
 
 Potato. — Slight invisible growth. 
 
 Stained by ordinary anilin dyes. Gram negative. 
 
 Glucose broth, unfermented. 
 
 Milk made alkaline. 
 
 The disease may be produced in monkeys by even small 
 amounts of pure culture. In man a chronic, remittent febrile 
 disease is produced, with sweating and arthritis. The mor- 
 tality is 2 per cent. A reaction can be obtained and is 
 diagnostic. 
 
 Agglutination — 1:30 dilution of serum will give positive 
 result, but the complement-fixation test considered more cer- 
 tain {which see). 
 
 Flies an agency for transmission. 
 
 Mode of Transmission. — Zammitt found that 50 per cent, 
 of the goats of Malta gave the agglutination reaction to the 
 micrococcus, and it was present in the milk in 10 per cent. 
 Monkeys fed on the milk contracted the disease. 
 
 Preventive measures instituted in 1906 have borne out the 
 theory that the milk of goats is the cause of Malta fever, and 
 since the practice of importing goats from Malta has stopped, 
 the disease has disappeared from Gibraltar. In Malta, 
 among the troops, the fever has been greatly reduced by 
 eliminating milk from the dietary. 
 
 CHAPTER XXm 
 PYOGENIC COCCI 
 
 Nearly all micro-organisms can produce suppuration, but 
 in the acute abscesses occurring in the skin and lymphatics and 
 accompanying all pus affections are found groups of micro- 
 cocci so regularly that they have been designated as the pus- 
 forming or pyogenic cocci. The two most important mem- 
 
164 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 bers of this group are the Staphylococcus pyogenes, and the 
 Streptococcus pyogenes, so named from the mode of division, 
 the former being found usually in clusters or bunches, the lat- 
 ter in chains. 
 
 Streptococcus Pyogenes (Rosenbach) : Streptococcus 
 Erysipelatis (Fehleisen). — Origin. — Fehleisen in 1883 dis- 
 covered this microbe in the lymph- 
 atics of the skin in erysipelas, and 
 he thought it the cause of the same. 
 Under the name Streptococcus 
 pyogenes, Rosenbach described an 
 identical coccus which has been 
 found in nearly all suppurative 
 conditions. 
 
 Fig. 76. — Streptococcus 
 pyogenes; culture upon agar- 
 agar two days old (Frankel 
 and Pfeiffer). 
 
 -Streptococcus pyogenes 
 (Jakob). 
 
 Form. — Small cocci singly and in chain-like groups. Spores 
 have not been found (Fig. 77). 
 
 Properties. — They are immotile; do not Hquefy gelatin. 
 
 Growth. — They grow slowly, usually on the surface, and 
 best at higher temperatures. 
 
PYOGENIC COCCI 165 
 
 Colonies. — In three days a very small grayish speck, which 
 hardly ever becomes much larger than a pin-head; under 
 microscope, looking yellowish, finely granular, the edges well 
 defined. 
 
 Stab-cultures. — Along the needle-track little separated col- 
 onies, like strings of beads, which after a time become one 
 solid white string. 
 
 Stroke-culture on Agar. — ^Little drops, never coalescing, 
 having a bluish tint, very transparent. 
 
 Potato. — No apparent growth. 
 
 Bouillon. — At 37° C. clouds are formed in the bouillon, 
 which then sink to the bottom, and long chains of cocci found 
 in this growth. 
 
 Loffler's Blood-serum and Serum Bouillon. — Development 
 more abundant in serum media. 
 
 Milk. — Good growth; produce lactic acid and coagulate 
 milk. 
 
 Preservation of Cultures. — In ice-chest, the cultures may be 
 kept alive several weeks at room temperature; they usually 
 die out in ten days. 
 
 Staining. — Easily colored with the ordinary stains. Gram's 
 method is also applicable. 
 
 Pathogenesis. — Inoculated subcutaneously in the ear of a 
 rabbit, an erysipelatous conditiori develops in a few days, 
 rapidly spreading from point of infection. 
 
 The micro-organism acts variously, depending upon the 
 nature of the lesion from which it originally was obtained. 
 Injected into the circulation, septicemia results. The more 
 virulent the affection, the more virulent the strain. 
 
 In man, inoculations have been made to produce an effect 
 upon carcinomatous growths, and erysipelas has always re- 
 sulted. When it occurs upon the valves of the heart, endo- 
 carditis results. Puerperal fever is caused by the microbe 
 infecting the endometrium, the Streptococcus puerperalis of 
 Frankel being the same germ. 
 
 In scarlatina, variola, yellow fever, cerebrospinal menin- 
 gitis, and many similar diseases, the microbe has been an 
 
1 66 ESSENTIALS OF BACTERIOLOGY 
 
 almost constant attendant. It is often associated with the 
 diphtheria bacillus in true diphtheria, and is the cause of 
 many of the diphtheritic complications. It is associated with 
 the influenza bacillus in acute ear suppurations; with pneu- 
 monia bacteria; with tubercle bacilli, and in such instances 
 usually causes high fever. In osteomyelitis and mastoiditis 
 it is usually the sole cause. 
 
 Streptococci in Milk. — ^In milk streptococci are often found, 
 but it is not considered an absolute indication of udder in- 
 flammation. 
 
 Protective Sera. — An antistreptococcic serum has been used 
 as a curative agent in puerperal fever, scarlatina, and other 
 diseases supposed to be due to this germ. The antistrepto- 
 coccic sera have been given an extensive trial in a variety 
 of suppurative and inflammatory diseases, but the results 
 are still under discussion. 
 
 Coley's Fluid. — A mixture of a culture of pyogenes and 
 prodigiosus has been used as an injection, with apparent 
 benefit, in inoperable cases of sarcoma, and is known as 
 Coley's fluid. 
 
 Immune Bodies. — Neither antitoxic nor bactericidal bodies 
 have been found in the blood of animals made resistant by the 
 injection of dead or attenuated cultures. 
 
 Polyvalent {Vaccines) Bacterins. — ^As it is possible that there 
 are several varieties of streptococci, and varying in patho- 
 genic properties, bacterins made from several strains have 
 been used as injections against suppurative processes, and 
 with some degree of success. Autogenous bacterins are 
 more reliable. 
 
 Distribution. — Streptococci can often be found in air, dust, 
 on the skin, on all the mucous surfaces, pharynx, conjunctiva, 
 tonsils. 
 
 Staphylococcus Pyogenes Aureus (Rosenbach). — 
 Origin. — Found commonly in pus (80 per cent, of all suppura- 
 tions), in air, water, and earth; also in sputum of healthy 
 persons. 
 
 Form. — Micrococci in clusters like bimched grapes, hence 
 
PYOGENIC COCCI , 1 67 
 
 the name staphylo, which means grape. They never form 
 chains. Spores have not been found, though the cocci are 
 very resistant (Fig. 78). 
 
 Properties. — Immotile; liquefying gelatin. Giving rise to 
 an orange-yellow pigment in the various cultures. 
 
 Growth. — It grows moderately fast at ordinary tempera- 
 ture, and can live without air, a facultative aerobin and an- 
 aerobin. 
 
 Colonies on Gelatin. — On second day small dots on the sur- 
 face, containing in their center an orange-yellow spot. The 
 
 Fig. 78. — Staphylococcus pyogenes albus (Jakob). 
 
 gelatin all around the colony is liquefied; the size is never 
 much greater than that attained the second day. 
 
 Colonies on Agar. — The pigment remains for a long time. 
 
 Stab-culture. — At first, gray growth along the track, which, 
 after three days, has settled at the bottom of the tube in a 
 yellow, granular mass, the gelatin being all liquid (Fig. 79). 
 
 Stroke-culture on Agar. — The pigment diffused over the sur- 
 face where the growth is in moist masses. 
 
 Potato. — ^A thin white layer which gradually becomes yel- 
 low and gives out a doughy smell. 
 
1 68 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Staining. — Very readily colored with ordinary stains; also 
 with Gram's method. 
 
 Pathogenesis. — When rabbits are injected with cultures of 
 this microbe into the knee-joint or pleura, they die in a day. 
 If injected subcutaneously, only a local action occurs, namely, 
 abscesses. 
 
 If directly into circulation, a general phlegmonous condi- 
 tion arises, the capillaries become plugged with masses of 
 cocci, infarcts occur in kidney and liver, 
 and metastatic abscesses form in viscera 
 and joints. Garre, by rubbing the culture 
 on his forearm, caused carbuncles to ap- 
 pear. 
 
 Several varieties of the pyogenic staph- 
 ylococci are recognized according to their 
 color-producing properties and slight vari- 
 ations of growth. Of these, the Staph- 
 ylococcus pyogenes aureus is the most 
 virulent, and is considered the type of the 
 group. They are always present on the 
 surface of the body, beneath the nails, in 
 the nose and mouth, in the dust of streets, 
 and on the floors of houses, and are found 
 in nearly all suppurative processes, whether 
 on the surface or internally. 
 
 Staphylococcus pyogenes albus dif- 
 fers frofn the preceding only in the absence 
 of pigment and in its slight virulence. 
 Welch describes a variety constantly found both on the skin 
 and in its deeper layers, which he calls the Staphylococcus 
 epidermidis albus. 
 
 Specific Therapy. — Sera have been found of no special 
 value. 
 
 Bacterins {Vaccines). — Twenty-four-hour-old agar surface 
 culture killed by heating at 60° C. is emulsified with normal 
 saline solutions and injected for the treatment of boils, ab- 
 scesses, and acne. The cultures should be autogenous, i. e., 
 
 Fig. 79. — Stab- 
 culture. Micro- 
 coccus pyogenes 
 aureus. 
 
PYOGENIC COCCI 169 
 
 derived from the person affected, although stock vaccines 
 have been used with some success. 
 
 The Opsonic Index. — It was proposed by Wright that the 
 opsonic index should be obtained before treatment with vac- 
 cines, although most of the treatment is now given without 
 such control. 
 
 Micrococcus Pyogenes Citreus (Passet). — This lique- 
 fies gelatin less rapidly than the pyogenes aureus, and forms 
 a citron-yellow pigment instead of the orange-yellow of the, 
 aureus. 
 
 Micrococcus Cereus Albus (Passet). — Differs from the 
 
 ^f .d 
 
 
 
 ^ 
 
 Fig. 80. — Micrococcus tetragenus in sputum (tubercle bacillus also). 
 
 pyogenes albus in the form of colony. A white, shiny growth, 
 like drops of wax; hence the name, cereus. 
 
 Micrococcus Cereus Flavus (Passet) . — A lemon-yellow 
 colored growth after a short time, otherwise not differing from 
 cereus albus. 
 
 Micrococcus Pyogenes Tenuis (Rosenbach). — Origin. 
 — Found in the pus of large inclosed abscesses. 
 
 Form. — Cocci, without any especial arrangement. 
 
 Properties. — ^Not much studied. 
 
 Growth. — Cultivated on agar, it forms clear, thin colonies; 
 along the needle- track an opaque streak, looking as if var- 
 nished over. 
 
lyo 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 V\ 
 
 .'y )> 
 
 ■V- 
 
 WUHc 
 
 Micrococcus Tetragenus (Koch; Ga&ky) .—Origin.— 
 
 Koch found this microbe in the cavity of a tuberculous lung. 
 Gaffky, in 1883, studied its pathogenic actions and gave it 
 the name it now bears. 
 
 Form. — Cocci which are gathered in the 
 tissues in groups of four, forming a square 
 — a tetrad. (See Fig. 80.) In artificial 
 culture sometimes found in pairs. A cap- 
 sule of light, gelatinous consistence sur- 
 rounds each tetrad. 
 
 Properties. — ^They are immobile; do not 
 liquefy gelatin. 
 
 Growth. — ^They grow well on all nutrient 
 media at ordinary temperature; are facul- 
 tative aerobic. They grow slowly. 
 
 Colonies in gelatin plates. In two days, 
 little white spots, which, when on the 
 surface, form little elevations of a porce- 
 lain-like appearance; under low power 
 they are seen very finely granulated. 
 
 Stab-culture. — Small, round, separated 
 colonies along the needle-track, and on 
 the surface a button-like elevation — a 
 form of "nail culture." (See Fig. 81.) 
 
 Potato. — ^A thick, slimy layer which can 
 be loosened in long shreds. 
 
 Staining. — Colored with the ordinary 
 anilin stains. Gram positive. 
 
 Pathogenesis. — White mice and guinea- 
 pigs die in a few days of septicemia 
 when injected with the tetragenus cul- 
 tures, and the micrococcus is then found 
 in large numbers in the blood and viscera. Field-mice are 
 immune. 
 
 In the cavities of tuberculous lungs, in the sputum of 
 phthisical and healthy patients, it is often found, but what 
 action it has upon man has not yet been determined. 
 
 Fig. 81.— Stab 
 culture. Micrococ 
 cus tetragenus. 
 
PYOGENIC COCCI 
 
 171 
 
 Morax-Axenfeld Diplobacillus of Conjunctivitis. — 
 
 This bacillus is found in the greater number of cases of con- 
 junctivitis. 
 
 Form. — ^A short, plump bacillus, usually in pairs and chains 
 of pairs. Non-motile (Fig. 82). 
 
 Growth. — With difficulty in blood-serum agar, it forrns small 
 pitted colonies or lacunae; liquefies. 
 
 Staining. — Does not take Gram, but stains readily. 
 
 Non-pathogenic for lower animals. 
 
 Fig. 82. — Morax-Axenfcld diplobacillus from conjunctival exudate 
 during course of subacute conjunctivitis (obj. B. and L., one-twelfth oil- 
 immersion) (Boston). 
 
 Bacillus Pyocyaneus (Gessard). — Synonyms. — Bacillus 
 fluorescens (Schroter) ; the bacillus of bluish-green pus. 
 
 Origin. — Found in 1882 in green pus in pyemia. Has been 
 found in water, in bandage material, in feces and street dust, 
 in the mouth of healthy individuals, and in all suppurating 
 conditions, especially in middle-ear discharge. 
 
 Form. — Small slender rods with rounded ends, easily mis- 
 taken for cocci. Often in groups of four and six, without 
 spores. 
 
172 ESSENTIALS OF BACTERIOLOGY 
 
 Properties. — Very motile; liquefy gelatin rapidly; a pecu- 
 liar sweetish odor and a blue pigment are produced in the 
 cultures. 
 
 Growth. — Develops readily at ordinary temperature, grow- 
 ing quickly and mostly on the surface; it is aerobic. Agar 
 plate: In two or three days a greenish iridescence appears 
 over the whole plate. 
 
 A bright green at first, causing fluorescence; then later a 
 blue pigment in deeper portion. 
 
 >><A 
 
 
 
 
 »*l\.«* 
 
 Fig. 83. — Bacillus pyocyaneus, from an agar-agar culture (X 1000) 
 (Itzerott and Niemann). 
 
 Gelatin Stab-cultures. — Mainly in upper strata, the lique- 
 faction funnel shaped, the growth gradually settling at the 
 bottom, a rich green shimmer forming on the surface, and the 
 gelatin having a deep fluorescence. 
 
 Potato. — The potato is soaked with the pigment, a deep 
 fold of green occurring on the surface. 
 
 Indol is produced. 
 
 In ear abscesses pure cultures have been found. 
 
 Bacillus fluorescens, found in water, is considered identical 
 
PYOGENIC COCCI 1 73 
 
 with Bacillus pyocyaneus and other fluorescent bacteria 
 are believed to be varieties. 
 
 Crystals develop on agar cultures in a short time. 
 
 Staining. — With ordinary anilin dyes. Gram negative. 
 
 Pathogenesis. — When animals are injected with fresh cul- 
 tures in the peritoneal cavities or cellular tissues, a rapidly 
 spreading edema with general suppuration develops. The 
 bacilli are found in the viscera and blood. 
 
 If a small quantity is injected, a local suppuration occurs, 
 
 Fig. 84. — Koch-Weeks' bacillus from conjunctival exudate at third day 
 of epidemic conjunctivitis (Boston). 
 
 and if the animal does not 'die, it then can withstand large 
 quantities. It is immune. 
 
 The Pigment. — Pyocyanin. — When the pus, bandages, and 
 dressings containing the Bacillus pyocyaneus are washed in 
 chloroform, the pigment is dissolved and crystallizes from the 
 chloroform in long needles. It is soluble in acidulated water, 
 which is turned red thereby, and when neutralized, the blue 
 color returns. It has no pathogenic action. It is an aromatic 
 compound. The bacillus has no especial action on the wound, 
 and is found sometimes in perspiration of healthy persons. 
 
174 ESSENTIALS OF BACTERIOLOGY 
 
 CHAPTER XXIV 
 GONOCOCCUS.— MENINGOCOCCUS 
 
 Micrococcus Gonorrhoeae (Gonococciis Neisser). — In 
 
 1879 Neisser demonstrated the presence of this germ in the 
 secretion of specific urethritis. 
 
 Form. — Cocci, somewhat triangular in form, found nearly 
 
 always in pairs, the base of one coccus facing the base of the 
 
 other and giving the appearance of a Vienna roll, hence the 
 
 German name, Semmel (roll), form. Four to twelve such 
 
 pairs are often found together. Immotile 
 
 (Fig. 86). In pus usually within the cells. 
 
 Culture. — No growth on ordinary media ; 
 
 ^^: on blood-serum or agar smeared with 
 
 -^ \0 blood, cultures have been obtained. The 
 
 ^X% temperature must be between 33° and 37° 
 
 *^*' C, and the growth occurs very slow^ly and 
 
 sparsely. 
 
 Wertheim's medium (q. v., p. 78) has 
 Fig. 85.— given the best results, 
 orrheal pus. Ani- Colonies. — Extremely delicate, translu- 
 
 lin -methyl-violet cent spots, separate, and of a slimy con- 
 ^■^ ^°^' sistence, appearing in one to two days. 
 
 Resistance. — The cultures live only a 
 few days at room temperature, but in the ice-chest they last 
 longer. A temperature of 45° C. destroys the gonococci and 
 it is but slightly resistant to the ordinary chemic antiseptics. 
 From the Blood. — In septicemic cases the gonococcus has 
 been isolated from the blood direct by drawing 5 to 10 c.c. 
 from a vein and adding it in equal parts of melted agar. 
 The mixture is poured into Petri dishes and developed in the 
 incubator at 37° C. 
 Staining. — Colored easily with all ordinary anilin stains. 
 Gram negative is one of its main diagnostic features. 
 
GONOCOCCUS. — MENINGOCOCCUS 
 
 175 
 
 The following method is recommended by Neisser: 
 The cover-glasses, with some of the urethral discharge 
 smeared upon them, are covered with a few drops of alcoholic 
 solution of eosin, and heated for a few minutes over the flame. 
 The excess of the dye is removed with filter-paper, then the 
 cover-glass placed in concentrated methylene-blue (alcoholic 
 solution) for fifteen seconds, and rinsed in water. 
 The gonococci are colored dark blue, the protoplasm of the 
 
 ^k 
 
 
 Fig. 86. — Gonococcus in urethral pus (X 1000) (Frankel and Pfeiffer). 
 
 cell pink, and the nucleus a light blue, the gonococci lying 
 in the protoplasm next to the nucleus (Fig. 85). 
 
 Bacterial Diagnosis. — Other bacteria are similar to the gon- 
 ococci in form; they are distinguished from the gonococcus 
 in that they are positive with Gram's method. The points 
 on which the diagnosis is to be made are the characteristic 
 biscuit shape, the intracellular position of the organism, its 
 failure to stain with Gram and very difficult to grow artificially 
 on common media. 
 
176 ESSENTIALS OF BACTERIOLOGY 
 
 Pathogenesis. — ^The attempts to infect the experiment ani- 
 mals with gonorrhea have so far been without success. In 
 man, upon a healthy urethra a specific urethritis was pro- 
 duced with even the twentieth generation of the culture. 
 Gonorrheal ophthalmia contains the cocci in great numbers, 
 and endocarditis and gonorrheal rheumatism are said to be 
 caused by the cocci. 
 
 The micrococci have been found long after the acute attack, 
 when only a very slight oozing remained, and the same were 
 found very virulent. 
 
 The specific inflammations of the generative organs of the 
 female are due to this organism gaining entrance through the 
 vagina. It is found chiefly in the superficial layers of the 
 mucous membrane. 
 
 Bacterins {Vaccines). — A number of vaccines have been pre- 
 pared in recent years for the treatment of gonorrhea and its 
 complications. The bacterins are made as described under 
 Bacterins. This method of treatment is still on trial. The 
 best results have been obtained in gonorrheal rheumatism 
 and epididymitis. 
 
 Toxins. — ^True toxins not found, but the cells contain poi- 
 sons that produce suppuration and death when injected into 
 the mice and guinea-pigs. 
 
 Allied Varieties. — A number of diplococci which resemble 
 the gonococcus in form are found in the vaginal secretions 
 and pus and may at times lead to a wrong diagnosis. The 
 meningococcus is very similar, but is easily cultivated and is 
 not apt to be found in the same secretions as the gonococcus. 
 
 Micrococcus citreus, albicans, and subflavus, described by 
 Bumm, are all Gram positive and grow readily on gelatin and 
 agar. 
 
 The gonococcus is distinguished from all these similar micro- 
 cocci by the tests enumerated above. 
 
 These characteristics, taken in toto, form sufficient features 
 for its ready recognition, and as it is often a serious question to 
 decide, not so much because of the patient's health as because 
 of his character, we should be very careful not to pronounce a 
 
GONOCOCCUS. — MENINGOCOCCUS 1 77 
 
 verdict until we have tested the micro-organism as above. 
 When the germ is found which answers to the above descrip- 
 tion, the process can be called gonorrhea without a doubt. 
 
 Diplococcus Intracellularis Meningitidis (Weichsel- 
 baum). — Synonyms. — Meningococcus; Micrococcus Meningi- 
 tidis. 
 
 Origin. — Found by Weichselbaum in epidemic cerebrospinal 
 meningitis in 1887. 
 
 Fig. 87. — Diplococcus intracellularis meningitidis in leukocytes. 
 Cover-glass preparation from peritoneal exudate in a guinea-pig (X2000) 
 (Wright and Brown). 
 
 Form. — ^A small coccus occurring in pairs, flattened against 
 each other, and contained within the leukocytes, resembling 
 gonococcus. No capsule (Fig. 87). 
 
 Properties. — Ferments sugars, with acid production. 
 
 Growth. — Best on blood-agar, serum-agar, and ascitic glu- 
 cose-agar at body temperature; good growth in twenty-four 
 hours. Sheep serum better medium. 
 
1 78 ESSENTIALS OF BACTERIOLOGY 
 
 Colonies. — Circular discs, whitish, almost transparent, mar- 
 gins, smooth. 
 
 Stain. — With basic anilin. Gram negative. Jenner's 
 blood-stain and Neisser stain best for spinal fluid specimens. 
 Loffler's alkaline methylene-blue a good stain. 
 
 Resistance. — Organisms very perishable one to three days. 
 Apparently destroyed by a self-elaborated ferment. Sun- 
 light destroys in a few hours. 
 
 Pathogenesis. — Causes epidemic cerebrospinal fever, prob- 
 ably by infection through the nasopharynx; the organism is 
 found in the spinal fluid and in other inflammatory exudates, 
 and can be seen in fluid obtained by lumbar puncture. 
 
 Ordinary laboratory animals immune, but Flexner has 
 succeeded in inoculating monkeys. 
 
 Agglutination. — On the fourth day; in dilution of i : 50 
 agglutination is had. 
 
 By the use of large quantities of meningococci injected into 
 a horse agglutinins, opsonins, and specific immune bodies 
 (amboceptor) can be produced. 
 
 Protective Serum. — Flexner has been able to obtain an anti- 
 toxin from monkey serum that has therapeutic properties in 
 man. Such an antiserum, when injected directly into the 
 spinal canal, has a curative action, destroying the cocci. 
 
 Bacterial Diagnosis. — By means of lumbar puncture the 
 spinal fluid is obtained and allowed to settle. Smears made 
 from sediment. Examined for bacteria. 
 
 Gram-positive organisms are either pneumococci, strepto- 
 cocci, or staphylococci. 
 
 Meningococcus is Gram negative and within the leukocytes, 
 and can be readily grown on blood-serum. If such an or- 
 ganism is present, the disease is undoubtedly cerebrospinal 
 meningitis. 
 
 Bacillus of Soft Chancre, Chancroid (Ducrey-Unna, 
 1889). — A diplobacillus which is specific has been described 
 by Ducrey as obtained from the secretion and in the depth 
 and margins of the chancroid. Unna's bacillus is narrower 
 and unbroken in the center (Fig. ^%). 
 
GONOCOCCUS. — MENINGOCOCCUS 1 79 
 
 Cultivation. — Cultivation has occurred on blood-agar, the 
 blood being added in the proportion of one to two. Colonies 
 sue small, round globules. 
 
 Staining. — With borax, methylene-blue, decolorized with 
 weak acetic acid. 
 
 Pathogenesis. — Probably a mixed infection occurs in most 
 
 Fig. 88. — Smear of pus of chancroid of penis (X 1500) (Davis) (photo- 
 micrograph by Mr. L. S. Brown). 
 
 chancroids, especially if buboes result. The bacillus of 
 Ducrey is not found in unopened buboes, though often con- 
 taminating the ulcerated ones. 
 
 The disease has been reproduced by inoculation of the 
 human subject. Laboratory animals are immune. 
 
l8o ESSENTIALS OF BACTERIOLOGY 
 
 CHAPTER XXV 
 
 ANAEROBIC BACTERIA (BACILLUS OF TETANUS; BACILLUS 
 OF MALIGNANT EDEMA, ETC.) 
 
 Similar in form and cultural requirements are a group of 
 bacteria which are found as a result of injury or the infection 
 of wounds. They vary greatly in the clinical symptoms 
 produced. 
 
 Bacillus of Tetanus (Nicolaier-Kitasato) . — Origin. — 
 Nicolaier found this bacillus in the pus of a wound in one 
 who had died of tetanus, describing it in 1884. 
 
 Kitasato isolated and cultivated this germ (1889). 
 
 Form. — A very slender rod. 
 
 When the spores form, a small swelling occurs at the spore 
 end, giving the bacillus a drum-stick shape (Fig. 89) . 
 
 Properties. — Not very motile, though distinctly so; lique- 
 fies gelatin slowly. The cultures give rise to a foul-smelling 
 gas. 
 
 Growth. — Develops very slowly, best at 36° to 38° C, and 
 only when all oxygen is excluded — an obligatory anaerobin. 
 In an atmosphere of hydrogen it flourishes. 
 
 Colonies on gelatin plates in an atmosphere of hydrogen. 
 Small colonies. After four days a thick center and radiating, 
 wreath-like periphery, like the colonies of Bacillus sub tills. 
 Pure cultures not easy to obtain (Fig. 90). 
 
 High Stab-culture. — ^The gelatin having 2 per cent, glucose 
 added and filling the tube. Along the lower portion of the 
 needle-track, a thorn-like growth, little needle-like points 
 shooting out from a straight line. The whole tube becomes 
 clouded as the gelatin liquefies, and then the growth settles 
 at the bottom of the tube (Fig. 91). 
 
 Agar. — On agar, in the incubator, the growth is quite 
 rapid, and at the end of forty-eight hours gas-bubbles have 
 formed and the growth nearly reached the surface. 
 
ANAEROBIC BACTERIA l8l 
 
 Bouillon. — Adding glucose to the bouillon gives a medium 
 in which an abundant growth occurs. 
 
 Stab-agar. — Inverted iir-tree appearance. 
 
 Milk. — Acid reaction and slow coagulation. 
 
 Inoculation of animals with suspected material may be 
 necessary as preliminary step. 
 
 Cultivation from Spores. — Kitasato, by exposing a portion 
 of suspected material to a temperature of 80° C. for one hour, 
 
 / < 
 
 i 
 
 ^-y-'- 
 
 '*^/>^ ^ 
 
 •• 
 
 ^ 
 
 / 
 
 \<i 
 
 Fig. 89. — Bacillus of tetanus with spores fX 1000) (Frankel and 
 
 Pfeiffer). 
 
 killed off all the other bacteria, but the spores of tetanus 
 escaped and these then vegetated. 
 
 Staining. — All the ordinary stains, Gram's method also, 
 the spores being colored in the usual way. 
 
 Pathogenesis. — A small amount of the pure culture injected 
 under the skin of experiment animals will cause, in two to 
 three days, death from true tetenus, the tetanic condition 
 starting from the point of infection. At the autopsy nothing 
 characteristic or abnormal is found, and the bacilli have dis- 
 
l82 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 appeared, except near the point of entrance. This fact is 
 explained as follows: 
 
 Toxins. — Several toxic products have been obtained from 
 the cultures, and they are produced in the body and give rise 
 
 Fig. 90. — Bacillus tetani: cul- 
 ture four days old in glucose-gela- 
 tin (Frankel and Pfeiffer). 
 
 Fig. 91. — Six days' culture of 
 bacillus of tetanus in gelatin (deep 
 stab) (Frankel and Pfeiffer). 
 
 to the morbid symptoms. These have been isolated, and 
 when injected singly, cause some of the tetanic symptoms. 
 Tetanospasmin, the most important for man. 
 
ANAEROBIC BACTERIA 1 83 
 
 Tetanolysin. — ^The blood and the urine contain the toxin 
 and are fatal to animals. 
 
 The virus enters the circulation, but does not remain in the 
 tissues. The toxin is most virulent. It acts on the end- 
 plates of the muscles, and then on the motor nerve-cells. 
 The incubation period is from two to fourteen days after 
 receipt of injury. The spores are very resistant to heat, 
 drying, and chemicals. 
 
 Burns and injuries from firearms, cartridges, powder, and 
 fireworks, a common cause of tetanus. 
 
 Immunity. — Kitasato, by inoculation of sterilized cultures, 
 has caused immunity to the effects of virulent bacilli. 
 
 An antitoxin obtained by Tizzoni and Cattani from the 
 serum of animals made immune by sterilized cultures is used 
 with curative effects in cases of tetanus in man. It is a 
 globulin, but differs from the diphtheria antitoxin. By pre- 
 cipitation with alcohol and drying in vacuo the antitoxin is 
 obtained in a solid state. The aqueous solution is used for 
 injection subcutaneously or subdurally through a trephine 
 opening. Its injection into the spinal canal by lumbar punc- 
 ture has also been recommended. Antitoxin is more beneficial 
 in chronic cases than in acute. 
 
 The dried antitoxin has been spread on the wound with 
 some curative action. 
 
 The antitetanic serum, to be effective, must be given very 
 early and in large doses. Its greatest use is in preventing 
 tetanus in wounds liable to be infected. From 50 c.c. to 100 
 c.c. of a billion-unit serum should be given in divided doses; 
 only sera with very high protective powers should be used. 
 
 United States Government Unit for Tetanus Antitoxin. — 
 *'The immunity unit is ten times the least quantity of anti- 
 tetanic serum necessary to save the life of a 350-gram guinea- 
 pig for ninety-six hours against the official test dose of a 
 standard toxin furnished by the Hygienic Laboratory at 
 Washington." 
 
 Habitat. — The bacillus is present in garden-earth, in man- 
 ure, and it has been isolated even from mortar. 
 
184 ESSENTIALS OF BACTERIOLOGY 
 
 The earth of special districts seems to contain the bacilli in 
 greater quantities. 
 
 Spores of tetanus may gain access to animal sera, and 
 if not properly destroyed, may produce tetanus during the 
 use of these products. Previous testing for the tetanus bacil- 
 lus should be made in the manufacture of all animal vac- 
 cines, antitoxins, etc. 
 
 Bacillus (Edematis Maligni (Koch, 1881) ; Vibrion 
 Septique (Pasteur, 1875). — Synonym. — Bacillus (Edematis, 
 
 Fig. 92. — Bacillus of malignani edema, from the body-juice of a guinea- 
 pig inoculated with garden-earth (X looo) (Frankel and Pfeiffer). 
 
 Origin. — ^In garden-earth, found also in severe wounds in 
 man when gangrene with edema had developed. Identical 
 with the bacillus found in Pasteur^ s septicemia. 
 
 Form. — Rods somewhat smaller than the anthrax bacillus, 
 the ends rounded very sharply. Long threads are formed. 
 Very large spores which cause the rods to become spindle 
 shaped. Resembles in form and culture B. chauvei (Fig. 92). 
 
ANAEROBIC BACTERIA 
 
 i8S 
 
 < 
 
 Properties. — Very motile ; liquefies gelatin ; gas is produced 
 in cultures but very little in the body. 
 
 Growth. — Grows rapidly, but only when the air is excluded, 
 and best in incubator at 37° C. 
 
 Roll Cultures {After Esmarch^s 
 Method). — Small, round colonies with 
 fluid contents, under low power, a mass 
 of motile threads in the center, and at 
 the edges a wreath-like border. 
 
 High Stab-culture. — With glucose 
 gelatin, the growth at first seen in the 
 bottom of the tube, with a general 
 liquefaction of the gelatin; gases de- 
 velop and a somewhat unpleasant odor. 
 
 Agar. — The gases develop more 
 strongly in this medium, and the odor 
 is more prominent. 
 
 Guinea-pig Bouillon. — In an atmos- 
 phere of hydrogen clouding of the en- 
 tire culture-medium without any floc- 
 culent precipitate until third day. Milk 
 coagulated. Glucose media marked gas 
 fermentation. 
 
 Staining. — Are stained with the ordi- 
 nary dyes, but Gram's method negative. 
 
 Pathogenesis. — When experiment ani- 
 mals, mice or guinea-pigs, are injected 
 with a pure culture under the skin, they 
 die in eight to fifteen hours, and the 
 following picture presents itself at the 
 autopsy: In guinea-pigs from the point 
 of infection, spreading over a large area, 
 an edema of the subcutaneous tissues 
 and muscles, which are saturated with 
 a clear red serous exudate, free from odor, and containing 
 great quantities of bacilli. 
 
 The spleen is enlarged, especially in mice. The bacilli are 
 
 Fig. 93. — Bacillus 
 of malignant edema 
 growing in glucose- 
 gelatin (Frankel and 
 Pfeiffer). 
 
l86 ESSENTIALS OF BACTERIOLOGY 
 
 not found in the viscera, but are present in great numbers on 
 the surface, i. ^., in the serous coverings of the different organs; 
 though when any length of time has elapsed between the 
 death of the animal and the examination, they can be found 
 in the inner portions of the organs, for they grow well upon 
 the dead body. In man they have been found in rapidly 
 spreading gangrene following wounds. 
 
 Habitat. — They are present in the soil, in putrefactions of 
 various kinds, and in dirty water. 
 
 Immunity. — Is produced by injection of the sterilized cul- 
 tures, and also the filtered blood-serum of animals dead with 
 the disease. 
 
 Bacillus Aerogenes Capsulatus (Welch, 1891). — 
 Synonym. — Bacillus Welchii; B. of Phlegmonous Emphysema 
 (Frankel). 
 
 Origin. — The intestine of man and animals, soil, sewage, 
 and water. 
 
 Form. — A thick bacillus, 3 to 6 )Li in length, frequently 
 capsulated. 
 
 Properties. — Not motile, anaerobic, forms spores chiefly in 
 cultures on blood-serum. Gram positive. 
 
 Growth. — Best at 37° C. 
 
 Gelatin. — Liquefied slowly or not at all. 
 
 Bouillon. — Forms gas. 
 
 Milk. — Coagulated and becomes acid. Under anaerobic 
 conditions. 
 
 Potato. — Thin, grayish- white growth with gas-production. 
 
 Forms gas in abundance in dextrose, lactose, or saccharose 
 media. 
 
 Pathogenesis. — Is not usually pathogenic for rabbits and 
 mice, though in guinea-pigs and birds it produces "gas phleg- 
 mons." It is sometimes found in autopsies on human sub- 
 jects, producing bubbles or cavities in the viscera (Schaum- 
 organe), but this is probably due to postmortem migration 
 of the germ from the intestine. It has been recovered from 
 the blood during life, however, and is the most frequent 
 cause of emphysematous gangrene. In man, infection of 
 wounds, through dirt, with this bacillus causes rapid emphy- 
 
ANAEROBIC BACTERIA 187 
 
 sema of the wound and a thin offensive discharge and fatal 
 outcome. After death the bacillus develops rapidly and 
 through the blood-vessels brings on general emphysema, with 
 large accumulation of hydrogen gas in all the organs and 
 subcutaneous tissue. Various foreign observers have de- 
 scribed organisms having similar properties, and have given 
 them such names as Bacillus perfringens, B. enteritidis sporo- 
 genes, Granulobacillus immobilis, B. saccharobutyricus. 
 
 Fig. 94. — Bacillus aerogenes capsulatus (from photograph by Professor 
 Simon Flexner). 
 
 but they were probably dealing with the Bacillus aerogenes 
 capsulatus. 
 
 Bacillus Enteritidis Sporogenes (Klein, 1895). — Re- 
 garded as identical with B. aerogenes capsulatus {q. v.). 
 
 Bacillus Chauvei. — Synonyms. — Bacillus of Symptomatic 
 Anthrax (BolUnger and Feser) ; Rauschhrand (German) ; Char- 
 bon symptomatique (Arloing, Cornevin, and Thomas). 
 
 Origin. — This bacillus, described in 1879, has been isolated, 
 and by animal inoculation shown to be the cause of the 
 "black-leg" or "quarter-evil" disease of cattle. 
 
i88 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Form. — Large slender rods, which swell up at one end or in 
 the middle for the spore (Fig. 95). 
 
 Properties. — They are motile, and liquefy gelatin quite 
 rapidly. 
 
 A rancid odor is developed in the cultures. 
 
 Cultures. — The growth occurs slowly, and only in an atmos- 
 phere of hydrogen, being anaerobic; grows best at 38° C; 
 under 15° C. no growth. 
 
 Glucose-gelatin. — In a few days little round colonies develop, 
 
 '■^^^ *,, 
 
 Fig. 95- 
 
 -Bacilli of symptomatic anthrax, with spores ( X 1000) (Frankel 
 and Pfeiffer). 
 
 which, under low power, show hairy processes around a com- 
 pact center. 
 
 Stab-cultures in Full Test-tubes. — The first growth in the 
 lower portion of the tube not very characteristic. Gases 
 develop after a few days, and the gelatin becomes liquid. 
 
 Agar at brood temperature, in twenty-four to forty-eight 
 hours, an abundant growth with a sour odor and abundant 
 gas-formation. 
 
ANAEROBIC BACTERIA 189 
 
 Staining. — Ordinary methods. Gram's method is nega- 
 tive, but the spores can be colored by the regular double stain 
 for spores. 
 
 Sugar Media. — Gas production. 
 
 Milk. — Rendered acid and coagulated. 
 
 Variability. — Great variation in cultures. 
 
 Toxin elaborated in fluid media fatal for rabbits when 
 injected intravenously. 
 
 Pathogenesis. — If a small amount of the culture be injected 
 under the skin of a guinea-pig, in twenty hours a rise of tem- 
 perature, pain at the site of injection, and a few hours later 
 death, occur. At the autopsy, the tissues are found black- 
 ened in color and soaked with a bloody, serous fluid; in the 
 connective tissue large collections of gas, but only in the neigh- 
 borhood of the point of infection. The bacilli are found in 
 great numbers in the serum, but only appear in the viscera 
 some time after death, when spores have developed. 
 
 The animals are usually infected through wounds on the 
 extremities; the stalls or meadows having been soiled by the 
 spore-containing blood of animals previously dead of the dis- 
 ease. '' Rauschbrand''' is the German name; "Charbon symp- 
 tomatique,^' the French, from the resemblance in its symp- 
 toms to anthrax. 
 
 Feeding experiments and infection from animal to animal 
 negative. 
 
 Dried virus inoculation practised by the United States 
 Government as preventive. 
 
 Immunity. — Rabbits, dogs, pigs, and fowl are immune by 
 nature, but if the bacilli are placed in a 20 per cent, solution of 
 lactic acid and the mixture injected, the disease develops in 
 them. The lactic acid is supposed to destroy some of the 
 natural resistance of the animal's cells. 
 
 Immunity is produced by the injections of these weakened 
 cultures, and also by some of the products which have been 
 obtained from the cultures. 
 
IQO ESSENTIALS OF BACTERIOLOGY 
 
 CHAPTER XXVI 
 HEMORRHAGIC SEPTICEMIA GROUP 
 
 Bacillus of Bubonic Plague (Yersin and Kitasato, 
 1894). — Synonym. — Bacillus Pestis. — Bubonic plague or pest 
 is an extremely infectious disease, more or less common in 
 China and the East, and is believed to have its origin in man 
 from rats and other rodents. It spreads with great rapidity, 
 
 Fig. 96. — Bacillus pestis in smear from rat's liver, showing bipolar 
 staining (X 720) (Wherry). 
 
 especially among those living under unsanitary conditions. 
 The ''Black Death" of the fourteenth century and the plague 
 epidemics of the seventeenth century are said to have been 
 the same disease. 
 
 Nearly at the same time Yersin and Kitasato, working 
 independently, discovered in the bubonic swellings and blood 
 
HEMORRHAGIC SEPTICEMIA GROUP IQI 
 
 of affected persons a distinctive bacillus which has conformed 
 to all the conditions necessary to make it the cause of the 
 disease. 
 
 Origin. — In the tissues and all the body-fluids and secre- 
 tions of affected individuals. 
 
 Form. — Short, thick rods with an indistinct capsule and 
 rounded ends. Growing in chains in fluid media (Fig. 96) . 
 
 Properties. — Immotile. Stains readily. No spores. Cul- 
 tivated best in oxygen, but is facultative anaerobic. Stains 
 stronger at the ends, producing bipolar appearance. Gela- 
 tin not liquefied. Easily destroyed by sunlight and drying. 
 Very resistant to cold. 
 
 Growth. — Best at 30° C; aerobic. 
 
 Gelatin. — At 22° C, in twenty-four hours, w^hite, point- 
 like colonies on the plates, with broad and flat surface, turn- 
 ing gray and then brown. Milk not curdled; slightly acid. 
 
 Stab. — Snow-white, spreading out on the surface to the 
 edge, and fluorescent. 
 
 Bouillon. — Granular precipitate, with clear fluid above. 
 When covered with oil and kept at rest, filaments hang down 
 from surface like stalactites. 
 
 Agar and Blood-serum. — Glass-like colonies like drops of 
 dew at first, then growing larger with iridescent edges. 
 
 Potato. — ^At 37° C. small white mass. Slow growth. 
 
 No gas formation in glucose media. 
 
 Staining readily with all basic dyes. Gram negative. 
 Capsule found in agar growths. 
 
 Pathogenesis. — ^After subcutaneous injection in rats death 
 follows in forty to sixty hours, with symptoms of severe toxe- 
 mia and convulsions. The point of infection shows a local 
 edema and inflammation of the lymphatics. All the organs 
 congested and surrounded by a bloody exudate. The charac- 
 teristic bacilli in all the tissues and secretions. Nearly all the 
 domestic animals are susceptible. Mosquitos and pigeons, 
 however, are immune — flies are not; fleas are a very impor- 
 tant element in the transmission, and the rat-flea may com- 
 mimicate the disease to the rat from man or from the rat to 
 
192 ESSENTIALS OF BACTERIOLOGY 
 
 man. Infected ground squirrels are supposed to be a factor 
 in spreading the disease. Animals protected from the flea 
 may live near infected animals without danger. Direct in- 
 fection by dust or other material seldom occurs. The sputum 
 of patients having the pneumonic t>pe is highly infectious. 
 Close personal contact with the infected is a means of trans- 
 mission. The main point of entrance is the skin. Fifty per 
 cent, of wild rats immune and not easily affected. 
 
 Products. — ^A toxin has been obtained and immunity has 
 been effected; the serum of immune animals has protective 
 properties. The serum likewise shows agglutinating powers, 
 and gives similar reactions to typhoid and cholera sera. 
 
 Habitat. — Not found in water, but most likely spreads from 
 the soil in damp and darkened areas. Rats become affected 
 first, and then, through fleas, affect man and other animals. 
 In man three forms of the disease are recognized according to 
 the mode of infection and course of the disease — viz., bubonic, 
 pulmonic, septicemic. 
 
 Vaccines. — ^The vaccines of Haffkine and Terni and Bandi 
 have been used extensively, and with some good results. 
 
 Antitoxins. — ^The antitoxins of Yersin and of Lustig have 
 been used, but without much result. Closely identified with 
 Bacillus pestis is the group known as the hemorrhagic sep- 
 ticemia bacteria 
 
 Bacteria of Hemorrhagic Septicemia (Hueppe, 1886). 
 — Under this heading Hueppe has gathered a number of 
 . bacteria very similar to the bacillus of chicken cholera, differ- 
 ing from it and each other but very little. They have been 
 described by various observers and found in different diseases. 
 
 The bacteria of this group color themselves strongly at the 
 poles, giving rise to the dumb-bell shape (Fig. 97). They 
 do not take the Gram stain; they are without spores, and do 
 not liquefy gelatin. 
 
 They have been divided into three groups. Bacillus avi- 
 septicus, as it appears in fowls; Bacillus bovisepticus, as it 
 attacks cattle; Bacillus suisepticus, as it attacks swine. 
 The prominent members of each group are: Bacillus of 
 
HEMORRHAGIC SEPTICEMIA GROUP 1 93 
 
 chicken cholera of Pasteur, bacillus of swine plague, and 
 bacillus of cattle-plague or pleuropneumonia. 
 
 Bacillus of Chicken Cholera (Perroncito, Pasteur, 
 1878). — Synofiyms. — Micrococcus cholera gallinarum; Microbe 
 en huit; avicidus bacillus; bacillus of fowl septicemia. 
 
 Origin. — In 1879 Perroncito observed this coccus-like ba- 
 cillus in diseases of chickens, and Pasteur, in 1880, isolated 
 and reproduced the disease with the bacillus in question. 
 
 Form. — At first it was thought to be a micrococcus, but it 
 has been found to be a short rod, about twice as long as it is 
 
 Fig. 97. — Bacillus of swine-plague (from photograph by E. A. de 
 
 Schweinitz). 
 
 broad, the ends slightly rounded. The center is very slightly 
 influenced by the anilin colors, the poles easily, so that in 
 stained specimens the bacillus looks like a dumb-bell or a 
 figure-of-8 (Microbe en huit). 
 
 Properties. — Does not possess self-movement; does not 
 liquefy gelatin; no spores. 
 
 Growth. — Occurs at ordinary temperature, requiring oxygen 
 for development. It grows very slowly. 
 13 
 
194 ESSENTIALS OF BACTERIOLOGY 
 
 Gelatin Plates. — In the course of three days little round, 
 white colonies, which seldom increase in size, having a rough 
 border and very finely granulated. 
 
 Stab-cultures. — A very delicate gray line along the needle- 
 track, which does not become much larger. 
 
 Agar Stroke Culture. — ^A moist, grayish-colored skin, more 
 appreciable at brood-heat. 
 
 Potato. — At 37° C, after several days, a very thin, trans- 
 parent growth. 
 
 Sugar Broth. — Acid fermentation, no gas. 
 Indol is formed. 
 
 Staining. — Methylene-blue gives the best picture. Gram's 
 method is not applicable. As the bacillus is easily decol- 
 orized, anilin-oil is used for dehydrat- 
 ing tissue sections, instead of alcohol. 
 
 Pathogenesis. — Feeding the fowls with 
 the bacilli or injecting them under the 
 skin will cause death in from twelve to 
 twenty-four hours, the symptoms pre- 
 
 Fig. 98.— Chick- ceding death being those of a severe 
 en cholera m blood ^ . . 
 
 (X 1000) (Frankel septicemia. 
 
 and Pfeiffer). The bacillus is then found in the blood 
 
 and viscera and the intestinal discharges, 
 the intestines presenting a hemorrhagic inflammation. 
 
 Guinea-pigs and sheep are immune. Mice and rabbits are 
 affected in the same manner as the fowls. 
 
 Immunity. — Pasteur, by injecting different-aged cultures 
 into fowls, produced in them only a local inflammation, and 
 they were then immune. But as the strength of these cul- 
 tures could not be estimated, many fowls died and the healthy 
 ones were endangered from the in.testinal excretions, which is 
 the chief manner of infection naturally, the feces becoming 
 mixed with the food. 
 
 Bacillus of Erysipelas of Swine (Loffler, Schiitz).— 
 Synonyms. — Schweinerotlauf bacillus (German); Rouget du 
 Pore (French). 
 
 Origin. — Found in the spleen of an erysipelatous swine by 
 Loffler in 1885. 
 
HEMORRHAGIC SEPTICEMIA GROUP I95 
 
 Form. — One of the smallest forms of bacilli known; very- 
 thin, seldom longer than i ix, looking at first like little needle- 
 like crystals. Spores have not been found. 
 
 Properties. — They are motile; do not liquefy gelatin. 
 
 Growth at ordinary temperature very slowly, and the less 
 oxygen, the better the growth. 
 
 Gelatin Plate. — On third day little silver-gray specks, seen 
 best with a dark background, coalescing after a while, pro- 
 ducing a clouding of the entire plate. 
 
 Stab-cultures. — In a few days a very light, silvery-like cloud- 
 ing, which gradually involves the entire gelatin; held up 
 against a dark object, it comes plainly into view. 
 
 Staining. — All ordinary dyes and Gram's method also. 
 
 Tissue sections stained by Gram's method show the bacilli 
 in the cells, capillaries, and arterioles in great numbers. 
 
 Pathogenesis. — Swine, mice, rabbits, and pigeons are sus- 
 ceptible; guinea-pigs and chickens, immune. 
 
 When swine are infected through food or by injection, a 
 torpidity develops with diarrhea and fever, and on the belly 
 and breast red spots occur which coalesce, but do not give 
 rise to any pain or swelling. The animal dies from exhaus- 
 tion in twenty-four to forty-eight hours. In mice the lids are 
 glued together with pus. 
 
 At the autopsy the liver, spleen, and glands are enlarged 
 and congested, little hemorrhages occurring in the intestinal 
 mucous membrane and that of the stomach. 
 
 Bacilli are found in the blood arid in all the viscera. 
 
 One attack, if withstood, protects against succeeding ones. 
 
 Immunity. — Has also been attained by injecting vaccines 
 of two separate strengths. 
 
 Bacillus Murisepticus (Koch) ; Mouse Septicemia. — 
 Origin. — Found in the body of a mouse which had died from 
 injection of putrid blood, and described by Koch in 1878. 
 
 Form. — Differs in no particular from the bacillus of swine 
 erysipelas, excepting that it is a very little shorter, making it 
 the smallest known bacillus. Spores have been found, the 
 cultures exactly similar to those of swine erysipelas. 
 
196 
 
 ESSENTIALS OE BACTERIOLOGY 
 
 The pathologic actions are also similar. Field-mice are 
 immune, whereas for house and white mice the bacillus is 
 fatal in two to three days. 
 
 Micrococcus of Mai de Pis (Nocard). — Gangrenous 
 mastitis of sheep. 
 
 Origin. — In the milk and serum of a sheep sick with the 
 ^'mal de pis." 
 
 .«-— / 
 '^/S'^ 
 
 
 
 Fig. 99. — Bacillus of mouse septicemia, from the blood of a mouse 
 ( X 1000) (Frankel and Pfeiffer). 
 
 Form. — Very small cocci, seldom in chains. 
 Properties. — Immotile; liquefying gelatin. 
 Growth. — Growth occurs best between 20° and 37° C, is 
 very rapid, and irrespective of oxygen. 
 
 Plates of Gelatin. — White round colonies, some on the sur- 
 
PROTOZOA 197 
 
 face and some in the deeper strata, with low power, appearing 
 brown, surrounded by a transparent areola. 
 
 Stab-culture. — Very profuse along the needle-track, in the 
 form of a cone after two days, the colonies having gathered 
 at the apex. 
 
 Potato. — A dirty gray, not very abundant, layer, somewhat 
 viscid. 
 
 Staining. — With ordinary methods; also Gram's method. 
 
 Pathogenesis. — If a pure culture is injected into the mam- 
 mary gland of sheep, a "mal de pis" is produced which 
 causes the death of the animal in twenty-four to forty-eight 
 hours. The breast is found edematous, likewise the thighs 
 and perineum; the mammas very much enlarged, and at the 
 nipples a blue-violet coloration. The spleen is small and 
 black ; other animals are less susceptible. In rabbits abscesses 
 at the point of infection, but no general affection. 
 
 CHAPTER XXVII 
 PROTOZOA 
 
 Protozoa are unicellular animal organisms, minute as bac- 
 teria, and differing from bacteria in the methods of repro- 
 duction. Their structure and functions are more complex, 
 although the borderland is ill defined. A nucleus is usually 
 present. 
 
 Divisions. — There are four grand divisions of protozoa: 
 (i) Sarcodina, containing 5500 species; (2) mastigophora, 
 containing 500 species; (3) infusoria, containing 700 species; 
 (4) sporozoa, containing 300 species. 
 
 Sarcodina are chiefly marine forms, with processes change- 
 able in shape. Examples: Ameba, foramnifera, entameba, 
 parasitic for man. 
 
 Mastigophora have undulating flagella and are known 
 as flagellates; to this division the trypanosomata belong. 
 Example: Trypanosoma. 
 
198 ESSENTIALS OF BACTERIOLOGY 
 
 Infusoria have fine ciliary processes or numerous delicate 
 flagella. Example: Balantidium. 
 
 Sporozoa have no motile organs, and are reproduced 
 by spores. To this division belong the coccidia of malaria 
 and the organisms discovered by Mallory in scarlatina. 
 Examples: Plasmodium, coccidium. 
 
 Life-cycle. — The complete cycle of reproduction has been 
 observed in only one of the pathogenic protozoa, namely, the 
 protozoa of malaria. 
 
 Methods of Cultivation. — Novy, Clegg and others have 
 obtained pure cultures of protozoa by the use of blood-agar 
 and animal tissue, or by cultivation with bacteria, on which 
 the ameba and other protozoa live. 
 
 Entamoeba Histolytica (Shaudinn, 1903). — Amoeba 
 Dysenteriae. — Found in the intestinal ulcers, feces, and 
 secondary liver abscesses in certain cases of dysentery. 
 Kartulis, in 1886, definitely established the cause, although 
 amebae were noted in feces by Lamb! in i860. A non- 
 pathogenic form. Amoeba coli, also occurs. The Amoeba dys- 
 enteriae is a unicellular animal organism, measuring 25 to 35 )Lt 
 in diameter, though larger and smaller forms occur. A nu- 
 cleus and a nucleolus are present; the protoplasm of the cell- 
 body is vacuolated, and often contains red blood-cells and 
 bacteria. In fresh, warm stools active ameboid motion may 
 be observed. The non-pathogenic form is smaller and never 
 contains red blood-cells. 
 
 Examination for Amebce. — From the slimy part of the 
 fresh feces a loopful is taken and diluted with salt solution 
 and examined with moderate power on a warm stage. ' Look 
 for contracting vacuole and motion. 
 
 Staining with hematoxylin eosin or eosin methylene-blue 
 after the film on a glass slide or cover-glass has been fixed 
 in hot alcohol or methyl alcohol. 
 
 Cultures. — On nutrient agar a loopful of feces is spread and 
 examined from day to day, transplanting the young amoebae 
 with their accompanying bacteria. 
 
 Pathogenesis. — Inoculation experiments with monkeys and 
 
PROTOZOA 199 
 
 dogs produce dysentery and liver abscess. In man, 50 per 
 cent, of human beings harbor non-pathogenic amebae, but 
 the pathogenic variety is found mainly in tropical countries, 
 where it produces serious lesions and often occurs in wide- 
 spread epidemics. 
 
 Source. — It is supposed to come from poor water supplies. 
 Amebic dysentery differs from the bacillary form in that no 
 severe toxic symptoms are present and the amebic disease 
 is more chronic. The Shiga bacillus, B. dysenteriae, is found 
 in the bacillary form of dysentery. 
 
 Life Cycle of the Malarial Sporozoa. — According to its 
 situation, the parasite exhibits two distinct phases of exist- 
 ence : in the human blood it passes through an asexual repro- 
 ductive cycle, known as schizogony, while in the body of the 
 mosquito it undergoes an entirely different series of sexually 
 reproductive changes, called sporogony. 
 
 I. The Asexual Cycle in Man. — An infected mosquito con- 
 veys the parasites into the blood of man as minute hyaline 
 bodies which enter the blood-cells. At first they are small, 
 round, colorless bodies, exhibiting more or less active ameboid 
 motion in the fresh blood. Sometimes, particularly in the 
 estivo-autumnal form, a ring shape is assumed. Their size 
 gradually increases and pigment-granules appear, while in 
 stained specimens a nucleus containing chromatin granules 
 is visible. As the parasite approaches maturity the chroma- 
 tin becomes scattered, and finally the protoplasm or mother- 
 cell, known as sporocyte, divides into six to twenty spores, 
 daughter-cells or merozoites, each containing a portion of the 
 chromatin. The number of spores formed and their arrange- 
 ment before segmentation takes place differ in the three 
 varieties and will be noted below. The spores burst through 
 the envelop of the red corpuscle and become free in the blood, 
 but speedily enter fresh corpuscles and pass through the 
 same series of changes. The febrile stage is synchronous 
 with sporulation and liberation of the young forms. 
 
 Certain of the parasites do not, however, go on to segmenta- 
 tion, but after reaching maturity, remain quiescent and form 
 
200 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 the so-called gametes or sexual types. In the tertian and 
 quartan varieties these are not very different from the mature 
 
 * ' Human Phase- [ Jj\ 
 
 ■ftn. 
 
 ^ THE EMDOOCHCTUS OR 'Nw-^v 
 
 U/il ' (^04 ASEXUAL. CyCLX. ^^^1 \ 
 
 THE 
 
 MOSQCJITO PHA3E 
 EXOQENOLJS 
 
 -Sexual- cvn f.. 
 
 Fig. 100. — Schema showing the human and mosquito cycles of the 
 malarial parasite: A, Normal red cell; B, C, D, E, red cells containing 
 amebulas or myxopods; F, G, H, sporocytes; J', K', L', M', microgame- 
 tocytes or male gametes; J", K", L", M", O, macrogametocytes, or 
 female gametes; N', M', microgametes; P, traveling vermicule; Q, 
 young zygote; R, S, zygotomeres; T, blastophore; U, mature zygote 
 (modified from Blanchard's diagram illustrating life-cycle of Coccidium 
 schubergi) (Rees, in "Practitioner," March, 1901). 
 
 organisms, but the estivo-autumnal gametes are crescentic in 
 shape and very characteristic. 
 
PROTOZOA 20I 
 
 2. The Sexual Cycle in the Mosquito. — The common mos- 
 quito is known as Culex and does not harbor the malarial 
 parasite. The anopheles species, spotted wings, is the true 
 host; only the females are bloodsuckers and responsible for 
 the spread of the disease. They take the infected blood 
 containing the male element and which represents the male 
 fertilizing element {micro gametes). These become detached, 
 and, entering a female gamete {macro gamete), a true sexual 
 fertilizing process takes place. In the alimentary canal of 
 the mosquito these fertilized cells penetrate the stomach- 
 walls and form cysts (oocysts) filled with a large number of 
 filiform spores (sporozoites), which are extruded into the 
 body cavity of the insect, and some of w^hich reach the salivary 
 glands, whence they are ejected when the mosquito bites. 
 This cycle of development takes seven or eight days. 
 
 Three Forms of Malarial Protozoa. — i. Plasmodium 
 Vivax, or The Tertian Form. — The adult forms are large, not 
 very refractile, and their outline is somewhat indistinct. 
 There is an abundance of fine pigment-granules, and the 
 ameboid motion is vigorous. Segmenting forms divide into 
 fifteen to twenty merozoites ; the sexual forms or gametes are 
 large The red cell containing the organism is swollen and 
 pale. Sporulation and, therefore, the malarial paroxysm 
 occur every forty-eight hours. 
 
 2. Plasmodium Malarice, the Quartan Form. — The organism 
 is smaller, is more refractile, and ij:s outline is more distinct. 
 The pigment is coarse and situated at the periphery of the 
 organism, while the protoplasmic motion is sluggish. Seg- 
 mentation forms only six to twelve spores, and has the regular 
 'Maisy-head" appearance; the gametes are small. The red 
 cells become dark in color, and the cycle requires seventy- 
 two hours. 
 
 3. Plasmodium Falciparum, or Malignant Tertian, or Estivo- 
 autumnal Form. — The adult forms are found mainly in the 
 spleen and other viscera, and do not very often occur in the 
 peripheral blood; their outline is sharp, and they are highly 
 refractile. The pigment is scanty and fine; the motion is 
 
202 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 e 
 
 ^•i.ttow.^' 
 
 00^ 
 
 ^ 
 
 ( Si^ 
 
 ^. 
 
 ^^"■•z- 
 
 n 
 
 J2 
 
 • • 
 
 J3 
 
 14- 
 
 IS 
 
 JS 
 
 IS 
 
 ® 9 
 
 IB 
 
 w 
 
 20 
 
 21 
 
 22 
 
 
 B3 
 
 ^ 
 
 25 
 
 2$ 
 
 .27 
 
 Fig. loi. 
 
PROTOZOA 203 
 
 active. A variable number of merozoites is formed — usually 
 six to twelve. The gametes are characteristic, being cres- 
 centic in shape and very resistant to quinin. The red cell 
 becomes shriveled and yellowish. The cycle usually takes 
 forty-eight hours, though it is somewhat variable. 
 
 Mixed infections with the different organisms or with two 
 or more broods of the same organism may occur, so that 
 quotidian and irregular paroxysms may be produced. 
 
 Transmission. — Malaria is spread by means of a mosquito, 
 the anopheles, in whose body the protozoon undergoes its 
 highest development. Man is the intermediate host; the 
 mosquito, the true host. 
 
 Methods of Examination for Malarial Organisms. — 
 I. Fresh preparations are made by placing a small drop of 
 blood on a slide and a cover-glass over it, so that only a thin 
 film is formed. A ring of vaselin is smeared over the edges of 
 the cover-glass to prevent evaporation. This is the best 
 method for studying flagellation and fertilization, but is less 
 satisfactory for routine clinical work than — 
 
 2. Stained Smears. — These are made by spreading a drop 
 of blood in a thin film over one slide with the edge of another, 
 drying in the air, and staining. Many stains have been 
 devised for the malarial organism, but Jenner's or Wright's 
 is sufficient for ordinary use: 
 
 (i) Jenner's Stain. — This is excellent for routine work, as 
 no preparatory fixation is required. The smears are dropped 
 into this stain for one to three minutes, without previous 
 fixation, and at once rinsed in distilled water. The malarial 
 parasites are stained blue, the cell-bodies a reddish brown. 
 
 Fig. loi. — Various forms of malarial parasites (Thayer and Hewet- 
 son): i-io inclusive, tertian organisms; 11-17 inclusive, quartan organ- 
 isms; 18-27 inclusive, estivo-autumnal organisms. 
 
 I, Young hyaline form; 2, hyaline form with beginning pigmenta- 
 tion; 3, pigmented form; 4, full-grown pigmented form; 5, 6, 7, 8, seg- 
 menting forms; 9, mature pigmented form; 10, flagellate form. 
 
 II, Young hyaline form; 12, 13, pigmented forms; 14, fully devel- 
 oped form; 15, 16, segmenting forms; 17, flagellate form. 
 
 18, 19, 20, Ring-like and cross-like hyaline forms; 21, 22, pigmented 
 forms; 23, 24, segmenting forms; 25, 26, 27, crescents. 
 
204 ESSENTIALS OF BACTERIOLOGY 
 
 (2) WrigMs Chromatin Stain. — This is the best of the 
 chromatin stains. For its preparation, which is quite com- 
 plicated, see Wright, Journal of Medical Research, vol. vii, 
 1902. It can be purchased already made. It is used as 
 follows : 
 
 1. The stain is poured over the film and allowed to remain 
 for one minute to secure fixation. 
 
 2. Add distilled water drop by drop until, a metallic scum 
 is formed on the surface. The staining now takes place and 
 requires two to three minutes. Wash in distilled water until 
 
 Fig. 102. — Pure culture of trypanosomes of mosquitos — Crithidia 
 fasciculata. Multiplication roset showing large and small cells. Nine- 
 day culture (Gen. i X 1500) (Novy, MacNeal, and Torrey), 
 
 a pinkish tint appears in the thin portions of the smear. The 
 body of the malarial parasite is stained blue, and its chromatin 
 a lilac to red color. The red cells are orange-pink. 
 
 If possible, examinations for malarial organisms should 
 always be made before quinin is administered. 
 
 Trypanosomata. — Trypanosomes are flagellate protozoa 
 found in the blood of various animals, and causing a number 
 of diseases, such as surra, dourine, and nagana, affecting 
 horses and cattle, especially in tropical countries, and causing 
 
PROTOZOA 205 
 
 the sleeping sickness of Africa, which is very fatal for human 
 beings. About 60 species have been described, and 10 dis- 
 eases are believed to be due to this form of organism. 
 
 Morphology. — A fusiform mass, containing at one end a 
 flagellum (Fig. 103). 
 
 In the livihg state these protozoa are very motile. In the 
 stained specimen chromatin granules are found and two or 
 more nuclei. From the smaller nucleus arises the undulatory 
 membrane, which passes into the flagellum and assists in the 
 wave-like motion. 
 
 Fig. 103. — Pure culture of trypanosomes of mosquitos — Crithidia 
 fasciculata. Part of roset of elongated crithidia with flagella directed 
 centrally (Gen. 39 X 1500) (Novy, MacNeal, and Torrey). 
 
 In the body fluids division occurs, first of the nucleus and 
 then of the protoplasm. 
 
 Cultivation. — Novy and MacNeal have succeeded in culti- 
 vating these protozoa on blood-agar, and multiplication goes 
 on rapidly, so that rosettes are formed with the flagella ar- 
 ranged around a common center. (See Figs. 102, 103, 104.) 
 
 Trypanosoma Lewisi (Kent, 1878). — Found in rats by 
 Lewis; not fatal to them, though often equaling the red cor- 
 puscles in number. It was one of the first of this group to 
 
2o6 ESSENTIALS OF BACTERIOLOGY 
 
 be described. The infection continues for two months with- 
 out producing any illness, and the animal is then immune. 
 
 Injection of infected rat blood into healthy rat causes the 
 latter to become infected. 
 
 The injection of serum from an immune rat will prevent 
 the disease in normal rats. 
 
 Cultivated best at 20° C. and is very resistant to cold. 
 The rat is probably infected by the bite of a flea or louse. 
 (See Fig. 105.) 
 
 / 
 
 Fig. 104. — Pure culture of trypanosomes of mosquitos — Crithidia 
 fasciculata. Elongated crithidia from same preparation as preceding 
 (Novy, MacNeal, and Torrey). 
 
 Trypanosoma Brucei (Plimmer and Bradford, 1894) 
 
 causes nagana, or tsetse-fly disease, a disease affecting horses, 
 cattle, and dogs in certain regions of South Africa. The 
 trypanosome of Bruce is less motile than that of Lewis. It 
 has been cultivated at 25° C, and is less resistant to cold. 
 All laboratory animals subject to infection. The rat dies in 
 ten days. 
 
 In the natural infection Bruce discovered that the tsetse- 
 fly transmitted the disease, but that it did so by first biting 
 some animal whose blood contained the trypanosome. The 
 
PROTOZOA 
 
 207 
 
 blood of infected animals contains the organism, and can, if 
 injected, produce the disease without the agency of the fly. 
 So far the tsetse-fly alone is responsible for the spread of the 
 infection. 
 
 Sleeping Sickness. — Trypanosoma Ugandense Gam- 
 biense (Button, 1904). — {T. Castellani, T. Hominis, T. 
 Neprevi.) — Sleeping sickness, or human trypanosomiasis, is a 
 disease peculiar to some parts of Africa. It is accompanied 
 by periods of fever, anemia, and, finally, a lethargy deepening 
 
 Fig. 105. — Trypanosome from blood of gray rat; stained with a 2 per 
 cent, aqueous solution of methylene-blue (Boston). 
 
 into coma and death. The disease may be rapid, and it 
 may last with recurrences for many years. Trypanosomes 
 identical with those found in nagana disease have been 
 found in the blood of infected persons, and described by 
 various observers, and given different names. 
 
 Monkeys, when inoculated with cerebrospinal fluid from 
 affected persons, develop a similar disease, and the parasites 
 are found in the blood. So far the organism has not been 
 cultivated. 
 
208 ESSENTIALS OF BACTERIOLOGY 
 
 A blood-sucking fly, known as the Glossina palpalis, is con- 
 sidered the means of infection. The fly is closely related to 
 the Glossina morsitans, or tsetse fly. The sleeping sickness in 
 man is most likely the same thing as the nagana of cattle. 
 
 Methods of Examinations. — From Blood. — A patient search 
 may fail to detect the organisms — a large amount of blood, 
 lo c.c, obtained by venesection — is centrifuged and the white 
 cells examined in hanging drop or stained smear. 
 
 Cerebrospinal fluid will at times give results. 
 
 Animal Inoculation. — The blood of suspected person in- 
 jected into monkeys or rats and the resulting infection stu- 
 died by above methods. 
 
 Staining. — The organism is best stained by Giemsa stain 
 or the Romanowsky method. 
 
 Trypanosoma Evansi (Steel, 1880). — Pathogenic for all 
 animals. 
 
 Discovered by Evans in the blood of horses suffering from 
 surra, a disease prevalent in India and the Philippine Islands. 
 The disease resembles nagana. 
 
 T. equiperdum and T. Rougetii are names given to similar 
 organisms found in dourine, a disease affecting horses in 
 southern France and Spain. Trypanosomes are found in fish, 
 oysters, birds, and frogs, and many varieties have been 
 described. 
 
 Herpetomonas (Leishman, 1903) (Leishman-Donovan 
 Bodies). — A disease called variously kala-azar, dum-dum 
 fever, tropical splenomegaly, is considered to be due to an or- 
 ganism somewhat related to the trypanosomes. 
 
 Smears are stained after fixation by the Wright or Roman- 
 owsky stains. Cultivation has succeeded on blood-media 
 made acid with citric acid. 
 
 The bedbug is considered instrumental in transmitting the 
 organism. 
 
 Piroplasma Bovis (P. Bigeminum) (T. H. Smith, 1893). 
 — Origin. — In the blood of animals suffering from Texas 
 cattle-fever. 
 
 Form. — A pear-shaped protozoon, found in pairs in the red 
 
THE MICRO-ORGANISM OF SYPHILIS AND ALLIED ORGANISMS 209 
 
 cells of the blood, the smaller ends of pear in opposition; 
 coarse ameboid movement. 
 
 Transmission. — An insect or tick (Boophilus bovis) be- 
 comes infected, and by its bite infects other animals. 
 
 Other similar sporozoa have been found in animal diseases 
 and in man in Rocky mountain fever. The P. hominis has 
 been described, but not definitely determined. 
 
 Rabies or Hydrophobia. — Negri Bodies (Negri, 1903). 
 — Origin. — Found in the nervous system of animals dying of 
 rabies (hydrophobia). 
 
 Form. — Round and oval, hyaline bodies, with a sharp out- 
 line and containing a nucleolus. The plasma is slightly 
 granular. They are regarded as protozoa. 
 
 Staining. — A smear from brain tissue is made on a cover- 
 glass and fixed in methyl-alcohol for five minutes; then stained 
 by Giemsa; stain for half-hour to three hours. 
 
 All mammals susceptible; man chiefly from bite of dog. 
 Only a small percentage of persons bitten by rabid dog be- 
 come infected — 16 per cent. 
 
 The virus resides in the saliva, and also in the central 
 nervous system. The Pasteur preventive is an accepted fact, 
 and depends for its power on a form of active immunization. 
 The virus used is obtained from dried spinal cord of infected 
 rabbits, gradually increasing the virulence, older cords first 
 used and then cords exposed to drying for lesser time. 
 
 CHAPTER XXVIII 
 
 THE MICRO-ORGANISM OF SYPHILIS AND ALLIED 
 ORGANISMS 
 
 Spirochaeta Pallida (Schaudinn, 1905). — Spironema 
 Pallidum; Treponema Pallidum. — Found in hereditary syph- 
 ilis in all organs, in chancre, and lymphatic glands, and in 
 secondary lesions, mucous patches, in the internal organs, 
 14 
 
2IO 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 and likewise in the tertiary lesions, the very latest being the 
 brain, and cerebrospinal fluid in cases of general paralysis, and 
 establishing the identity of this disease with cerebral syphilis. 
 Form. — A minute, spiral-shaped organism, with 6 to 20 
 curves, ends tapering. Actively motile in fresh specimen 
 (Fig. 106), intracellular, and affecting glandular epithelium. 
 Staining. — The organism requires special staining, and a 
 number of complicated methods have been introduced by 
 
 different investigators. 
 The Giemsa stain is 
 said to give the best 
 results. (See Staining 
 Fluids, p. 47.) 
 
 The slide is fixed, 
 dried in air, hardened 
 in absolute alcohol 
 twenty - five minutes, 
 stained with dilute 
 stain (i drop to i c.c. 
 ^•"^^'^'^^'^ .*' ^ ^^ water) for ten min- 
 
 ■""'"'■'" utes, washed in water, 
 
 and mounted. 
 
 In tissues the organ- 
 ism can be shown by 
 fixing with silver ni- 
 trate after the manner 
 of Ramon y Cajal. The 
 tissue is — (i) Hardened in formalin for twenty-four hours 
 (the sections should be thin) ; (2) washed in water for one 
 hour; (3) alcohol, twenty-four hours; (4) i^ per cent, silver 
 nitrate solution in incubator at 37° C, three days; (5) washed 
 in water twenty minutes; (6) placed in mixture of pyrogallic 
 acid, 4 parts; formalin, 5 parts; distilled water, to make 100 
 parts, and kept in dark bottle for forty-eight hours; (7) 
 washed in water and alcohol and then embedded in paraffin 
 and sectioned. Spirochaetae black, tissues, pale yellow. Or 
 counterstain of f uchsin can be employed. 
 
 Fig, 106. — Spirochseta pallida. Micro- 
 photograph made by Dr. R. E. Lavenson 
 from a specimen prepared by H. Fox 
 (Stengel). 
 
THE MICRO-ORGANISM OF SYPHILIS AND ALLIED ORGANISMS 211 
 
 The Iftdia Ink Method. — A drop of fluid from a lesion is 
 mixed with a drop of India ink upon a clean glass slide and 
 allowed to dry. Examine with oil-immersion lens. The 
 spirilla appear dark in a mass of carbon particles. By using 
 dark ground illumination, the organism appears brightly 
 refractive. 
 
 Culture Methods. — Noguchi, by using a serum water (i 
 part sheep or horse serum, 3 parts water, and adding a piece 
 of sterile rabbit's kidney or testicle), under strict anae- 
 robic conditions at 35° C. succeeded in cultivating the organ- 
 ism direct from lesions in man. After several transfers the 
 organism will grow on agar containing the bit of tissue. 
 
 Inoculation Experiments. — Pure cultures inoculated into 
 rabbits and monkeys produce lesions resembling .the primary 
 sores, and the blood of such animals gives a Wassermann 
 reaction. Cutaneous inoculation on eyebrows and genitals 
 of material from primary and secondary lesions produces 
 results in from fifteen to fifty days. 
 
 Wassermann Reaction. — In 1906 Wassermann, Neisser, 
 and Bruck described a method of making the diagnosis of 
 syphilis by demonstrating in the blood and spinal fluid of 
 a patient complement-binding substances not present in 
 normal blood. 
 
 Technic. — The following reagents are employed: (i) Syphi- 
 litic antigen; (2) serum to be tested; (3) fresh guinea-pig 
 serum; (4) washed sheep corpuscles and antisheep ambo- 
 ceptor. 
 
 The antigen is an alcoholic extract of liver from a congenital 
 syphilitic, and is prepared by extracting the ground-up liver 
 with five volumes of absolute alcohol for ten days and then 
 filtering. 
 
 Complement is normal guinea-pig serum. 
 
 Antisheep amboceptor is obtained by injecting into a rabbit 
 2, 4, 6, 8, and 12 c.c. of washed sheep corpuscles on the first, 
 tenth, nineteenth, twenty-eighth, and thirty-seventh days 
 respectively. Nine days after the last injection the animal 
 is bled to death from the carotid and the blood collected in 
 
212 ESSENTIALS OF BACTERIOLOGY 
 
 sterile test-tubes. After clotting has taken place the clear 
 serum is removed. This is the amboceptor serum. 
 
 Washed sheep corpuscles are obtained by centrifuging de- 
 fibrinated sheep blood, pipeting off the serum, replacing it 
 with normal salt solution, shaking, and again centrifuging. 
 This is repeated three times. 
 
 Patient's serum obtained from blood from the patient's arm 
 is heated thirty minutes at 56° C. to destroy complement. 
 
 Titration or Testing of Reagents. — Titrate amboceptor. 
 One c.c. of a 5 per cent, suspension of washed sheep cor- 
 puscles in salt solution and o.i c.c. of fresh guinea-pig 
 serum are added to a series of test-tubes. The amboceptor 
 serum is then added so that each tube receives more than the 
 preceding one. Salt solution is added to make 5 c.c. and 
 the tubes incubated for two hours at 37° C. with occasional 
 shaking. That tube in which complete hemolysis has taken 
 place in just two hours contains \ unit of amboceptor. 
 
 Titration of Complement. — Into each of a series of tubes 
 place I c.c. of the corpuscle suspension and \ unit of ambo- 
 ceptor. Next add 0.6, 0.7, 0.8, 0.9, i, i.i, 1.2 c.c. of fresh 
 guinea-pig serum respectively and incubate for two hours, 
 shaking occasionally. Those tubes which show complete 
 hemolysis in just two hours contain i unit of complement. 
 
 Titration of Antigen. — Two-tenths c.c. of serum, pre- 
 viously heated to 56° C. for a half-hour, from a known, un- 
 treated case of secondary syphilis, and i unit of complement 
 are added to each of a series of test-tubes. Antigen is now 
 added, so that each tube contains more than the preceding 
 one, and salt solution added and brought to 3 c.c. The 
 mixture is incubated for one hour at 37° C, at the end of 
 which time 2 units of amboceptor and i c.c. of corpuscle 
 suspension are added and the tubes returned to the incubator. 
 After a short period the tube containing the smallest amount 
 of antigen will show complete hemolysis. As the dose of 
 antigen is increased the amount of hemolysis is decreased 
 until a point is reached at which no hemolysis takes place 
 even after twenty-four hours. The first tube in the series 
 
THE MICRO-ORGANISM OF SYPHILIS AND ALLIED ORGANISMS 213 
 
 which shows no hemolysis after twenty-four hours contains 
 i' unit of antigen provided tw^ice that amount will not prevent 
 hemolysis when no serum is added. 
 
 Having found out the exact amount of guinea-pig serum 
 (complement) necessary to unite with hemolytic amboceptor 
 (rabbit serum) in order to hemolyze blood-corpuscles, this 
 amount is mixed with syphilitic antigen plus the suspected 
 syphilitic serum amboceptor, and incubated for one hour at 
 37° C. // the amboceptor is syphilitic, it will combine with 
 the antigen and guinea-pig complement. To find out if the 
 complement has been bound, the hemolytic amboceptor and 
 its antigen sheep corpuscles are added to the mixture, 
 and if no hemolysis takes place, the complement is fixed and the 
 patient'' s serum contains the syphilitic antibodies or amboceptors. 
 
 To Set Up Test. — Nine tubes needed for Wassermann reac- 
 tion and control. Into each tube i c.c. diluted complement 
 guinea-pig serum. Into tubes 1,2, and 9, 0.2 c.c. of patient's 
 serum. Into tubes 3 and 4, control, syphilitic serum 0.2 c.c; 
 in 5 and 6, normal serum as control, 0.2 c.c. ; antigen extract, 
 I unit placed in i, 3, 5, and 7. 
 
 To each tube is now added sufficient normal salt solution 
 to make 3 c.c. Tubes gently shaken and placed in incubator 
 at 37° C. one hour. At end of the hour to each tube is added 
 
 1 unit of suspension sheep corpuscles, and to all but No. 9 
 
 2 units of standard amboceptor, in i c.c. saline. 
 
 The tubes again placed in incubator for one hour, readings 
 taken, and then placed in ice-box twenty-four hours, when 
 final results noted. If Wassermann positive — 
 
 No. I. No hemolysis. 
 
 No. 2. Complete hemolysis. 
 
 No. 3. No hemolysis. 
 
 No. 4. Complete. 
 
 No. 5. Complete. 
 
 No. 6. Complete. 
 
 No. 7. Complete. 
 
 No. 8. Complete. 
 
 No. 9. No hemolysis. 
 
214 
 
 ESSENTIALS OF BACTERIOLOGY 
 WASSERMANN SCHEME 
 
 6 
 
 < 
 
 5 
 
 Patient's Serum 
 
 Known Syphilitic 
 Serum 
 
 Bi 
 M 
 
 in 
 
 < 
 
 "Si 
 fi 
 o 
 
 S 
 o 
 
 1 
 
 < 
 
 
 en 
 
 1 
 
 o 
 U 
 
 M 
 M 
 
 1 
 
 
 + Result 
 
 I 
 
 2 
 
 3 
 4 
 5 
 6 
 
 7 
 8 
 
 9 
 
 I c.c. 
 I c.c. 
 I c.c. 
 I c.c. 
 I c.c. 
 I c.c. 
 I c.c. 
 I c.c. 
 I c.c. 
 
 0.2 C.C. 
 0.2 C.c. 
 
 0.2 C.C. 
 
 • 
 0.2 C.C. 
 
 0.2 C.C. 
 0.2 C.C. 
 
 I 
 I 
 I 
 I 
 
 s 
 'il 
 
 1 
 
 1 
 
 1/2 
 
 I 
 
 
 1 
 
 u 
 1— 1 
 
 No hemolysis. 
 
 + 
 Complete 
 
 hemolysis. 
 No hemolysis. 
 
 + 
 Complete 
 
 hemolysis. 
 Complete 
 
 hemolysis. 
 Complete 
 
 hemolysis. 
 Complete 
 
 hemolysis. 
 Complete 
 
 hemolysis. 
 As a rule, no 
 
 hemolysis. 
 
 Noguchi modification of the Wassermann reaction 
 
 consists in using human corpuscles and antihuman ambocep- 
 tor, and, as antigen, acetone insoluble lipoids. 
 
 Antigen. — Extract a finely ground ox-heart with lo vol- 
 umes of absolute alcohol at 37° C. for several days; filter 
 and evaporate the extract (using an electric fan and not heat) 
 almost to dryness. Extract the residue with ether; decant, 
 evaporate the ether, and redissolve in the smallest quantity of 
 pure water-free ether. To this ethereal solution add 5 
 volumes of water-free acetone. A precipitate forms which 
 is the antigen. The precipitate is dissolved in purest methyl- 
 alcohol in the proportion of 3 per cent. For use, i c.c. of 
 this alcoholic solution is mixed with 9 c.c. of salt solution. 
 
 Titration of Antigen. — (i) Hemolytic Action. — A tube con- 
 
THE MICRO-ORGANISM OF SYPHILIS AND ALLIED ORGANISMS 21$ 
 
 taining 0.4 c.c. of the antigen emulsion, o.i c.c. of 10 per 
 cent, suspension of corpuscles, and 0.6 c.c. of salt solution 
 should show no hemolysis after two hours at 37° C. 
 
 (2) Anticomplementary Bodies. — A tube containing 0.4 c.c. 
 of antigen, o.i c.c. of a 40 per cent, dilution of complement, 
 2 units of amboceptor, and 0.6 c.c. of salt solution is incu- 
 bated for one hour and 0.1 c.c. of 10 per cent, corpuscle sus- 
 pension added. In two hours there should be complete 
 hemolysis. 
 
 (3) Antigenic Properties. — After incubating for one hour a 
 tube containing 0.02 c.c. antigen, 0.02 c.c. of a known syphilitic 
 serum, 0.1 c.c. of a 40 per cent, dilution of complement, 2 
 units of amboceptor, and 0.8 c.c. of salt solution, 0.1 c.c. of a 
 10 per cent, corpuscle suspension is added, and the tube 
 returned to the incubater. At the end of two hours there 
 should be no hemolysis. 
 
 (4) Amboceptor and complement are titrated the same as 
 in the Wassermann reaction, except that a i per cent, sus- 
 pension of human corpuscles and 0.02 c.c. of complement 
 and antihuman amboceptor are used. 
 
 NOGUCHI SCHEME 
 
 
 1 
 
 
 
 
 
 
 
 < 
 
 
 
 
 After Ten Hours 
 
 f 
 
 I 
 
 I . . 
 
 
 oT • 
 
 u 
 
 I i 
 
 
 
 No hemolysis. 
 
 Patients ] 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Positive 
 
 2 
 3 
 
 I 
 
 I 
 
 
 
 d 
 
 I 
 
 
 
 1 
 
 Complete hemol- 
 ysis. 
 No hemolysis. 
 
 control ■ 
 
 4 
 
 
 I 
 
 
 
 r^ 
 
 
 
 
 2'^ 
 
 3 
 
 Complete hemol- 
 
 Negative f 
 
 S 
 
 
 
 I 
 
 c3 
 
 S -2 
 
 I 
 
 5 
 
 3 
 
 a c^ 
 
 (S3 
 
 :3 
 
 ysis. 
 Partial, later com- 
 
 control 
 
 6 
 
 
 
 I 
 
 "a 
 
 
 
 1 
 
 1— 1 
 
 plete. 
 Complete hemol- 
 
 
 
 
 
 
 ^ 
 
 U 
 
 
 
 
 
 ysis. 
 
2l6 ESSENTIALS OF BACTERIOLOGY 
 
 Explanation of Noguchi Modified. — Requires six tubes: 
 
 In I and 2, one drop serum to be tested; in 3 and 4, one 
 drop known syphilitic serum; in 5 and 6, one drop normal 
 serum. 
 
 To each tube add i c.c. i per cent, suspension washed 
 human blood-corpuscles, and o.i c.c. 40 per cent, fresh 
 guinea-pig serum (complement). 
 
 Into 1,3, and 5, one drop antigen solution. 
 
 Incubate at 37° C. one hour, then add 2 units antihuman 
 amboceptor to each tube. Incubate two hours and read 
 reaction every hour for next ten hours, keeping tubes at 
 room temperature. 
 
 Tubes 2, 4, 6, complete hemolysis. 
 
 Tube 5, complete hemolysis. 
 
 Tube 3, no hemolysis. 
 
 Tube I, no hemolysis. 
 
 Results of Wassermann Test. — Eighty per cent, of primary 
 cases give a positive result, but a negative reaction in this 
 stage does not mean much, as nearly 20 per cent, of cases are 
 negative. 
 
 95 per cent, of secondary cases give a positive reaction. 
 
 85 per cent, of tertian positive. 
 
 90 per cent, congenital forms strongly positive. 
 
 100 per cent, general paresis positive. 
 50 per cent, locomotor ataxia positive. 
 65 per cent, latent tertiary forms. 
 
 Luetin Reaction (Noguchi). — An emulsion of a pure 
 culture of the spirochetes of syphilis heated to 60° C. for 
 one hour, and made sterile, is called luetin. 
 
 When applied subcutaneously by means of a fine needle, 
 an erythema lasting forty-eight hours results in normal 
 persons, but in persons affected with tertiary, latent, and 
 congenital syphilis after forty-eight hours a small induration 
 or papule appears, which at times becomes vesicular and 
 pustular, increasing in redness and turning bluish red in 
 three or four days. It is an adjunct to other tests for syphilis. 
 
THE MICRO-ORGANISM OF SYPHILIS AND ALLIED ORGANISMS 2X7 
 
 Yaws. — Spirochetes similar and possibly identical with 
 those of syphilis have been found in this tropical disease. 
 Spirillum of Relapsing Fever (Obenneier, 1873). — 
 
 Synonym. — Spirochceta Ohermeieri. 
 
 The definite classification of this organism has not been 
 made. Some regard it now as a protozoon, and one of a 
 group in which numerous other spirilla belong. 
 
 Origin. — Found in the blood of recurrent fever patients, 
 described in 1873. 
 
 Form. — Long, wavy threads (16 to 40 /x long), a true spiril- 
 lum; flagella are present (Fig. 107). 
 
 Fig. 107. — Spirochaeta Obermeieri from human blood (Kolle and Wasser- 
 
 mann). 
 
 Properties. — Very motile. Has not been cultivated. 
 
 Staining. — Ordinary anilin stains. Bismarck-brown best 
 for tissue sections. 
 
 Pathogenesis. — Found in the organs and blood of recurrent 
 fever. Man and monkeys inoculated with blood from one 
 suffering from this disease become attacked with the fever, 
 and in their blood the spirillum is again found. It is found in 
 the blood only in the relapses (during the fever). After the 
 attack the spirilla gather in the spleen and gradually die 
 
215 ESSENTIALS OF BACTERIOLOGY 
 
 there. It has been found in the brain, spleen, liver, and 
 kidneys. In the secretions it has not been discovered. 
 
 Agglutinating substances have been developed. Immu- 
 nity has been produced in rats, and the serum has anti- 
 toxic properties. 
 
 Transmission. — The bedbug retains the spirillum in its 
 blood and is considered an important factor in spreading the 
 disease. 
 
 African Tick Fever. — A spirochaete similar to that of 
 relapsing fever has been observed in ticks, which conveyed 
 a disease to monkeys similar to the above fever. 
 
 CHAPTER XXIX 
 FILXERABLE ORGANISMS 
 
 Filterable or Ultra-microscopic Organisms. — There are 
 many widely distributed infectious diseases that have all 
 the characteristics of germ or bacterial diseases, but so far 
 the organism has not been found. It has been suggested 
 that the bacteria are so small that they pass through the 
 ordinary germ-filters and are beyond the powers of the 
 microscope. By aid of the ultra-microscope twice the mag- 
 nification of the usual oil-immersion lens can be obtained, 
 and it is hoped that the cause of some of these diseases will 
 thereby be ascertained. The instrument is still imperfect, 
 though even so it has opened up a new field of research. 
 
 Such diseases as measles, foot and mouth disease of cattle, 
 typhus fever, small-pox, scarlatina, and infantile poliomyeli- 
 tis (epidemic infantile paralysis) are assumed to be due to 
 these bacteria. 
 
 Small-pox and Vaccinia. — The exciting agent of small- 
 pox is still unknown, but numerous bacteria and protozoon- 
 like bodies have been described and given etiologic signiii- 
 
FILTERABLE ORGANISMS 219 
 
 cance by various authors. There is some evidence in favor 
 of Funck's belief that vaccinia is caused by a protozoon, the 
 Sporidium vaccinale. Animals inoculated with this organ- 
 ism developed both vaccinia and variola. It is possible that 
 the organism causing small-pox is a filterable one, and 
 beyond the present methods of research. 
 
 Yellow Fever. — For some years it was thought that a 
 bacillus, called Bacillus icteroides by Sanarelli, was the cause 
 of yellow fever. The earlier work of Sternberg was disproved 
 when it was shown that his bacillus, Bacillus X, was identical 
 with the colon group, and Reed and Carroll found that San- 
 arelli's germ was an allied organism. 
 
 It is now known that a special species of mosquito, Ste- 
 gomyia fasciata, conveys the infection and acts as a culture- 
 medium for some unknown microorganism, possibly a proto- 
 zoon, which must undergo certain changes to become virulent. 
 
 Only by the bite of a mosquito infected with the blood of a 
 yellow-fever patient or by direct inoculation of such blood can 
 yellow fever be transmitted. 
 
 The experiments made so far show that the germ is de- 
 stroyed by a temperature of 55° C. for ten minutes. It can 
 pass through a Berkefeld filter, and is, therefore, extremely 
 minute, ultra-microscopic, but no one has as yet been able to 
 find any distinctive organism in the blood. 
 
 Measles. — Recent experiments (Anderson and Gold- 
 berger) demonstrated the virus in the nasal and mouth secre- 
 tions, and this secretion, collected forty-eight hours before 
 eruption, when inoculated into monkeys reproduced measles 
 in them. The infection was not possible forty-eight hours 
 after the eruption nor from the desquamation. 
 
 Typhus fever, or Brill's disease, has a virus which is 
 non-filterable and which resides in the plasma of the blood. 
 Monkeys can be inoculated with the disease. Transmitted 
 by lice. 
 
 Acute Poliomyelitis. — The virus is contained in brain 
 and spinal cord and also in the mucous membrane of the 
 nose, in the salivary glands, and cerebrospinal fluid; it is 
 
220 ESSENTIALS OF BACTERIOLOGY 
 
 very little resistant to heat. Monkeys inoculated through 
 the nose or directly into the brain. Immunity is produced 
 and an immune serum as preventive is obtained. The 
 stable-fly is supposed to act as a carrier of infection. 
 
 CHAPTER XXX 
 YEASTS AND MOLDS 
 
 In works on bacteria these true fungi, yeasts and molds, are 
 usually considered. They are so closely related to bacteria, 
 and so often contaminate the culture-media, and are so similar 
 in many respects, that a description is almost a necessity. 
 
 But there are several thousand varieties, and we cannot 
 attempt to describe even all the more important ones. A 
 description of a few of the more common kinds must suffice. 
 
 Blastomycetes (budding fungi) or yeasts increase 
 through budding; the spores are attached to the mother-cell 
 like a tuber on a potato (Fig. io8). 
 
 Yeasts are the cause of alcoholic fermentation in the sac- 
 charoses, and hence called saccharomycetes. 
 
 Saccharomyces Cerevisiae (Torula Cerevisiae). — This 
 is the ordinary beer-yeast. 
 
 Form. — Round and oval cells; a thin membrane inclosing a 
 granular mass, in which usually can be seen three or four 
 irregular-shaped spores. When these become full grown, 
 they pass through the cell-wall and form a daughter-cell. 
 Sometimes long chains are produced by the attached daugh- 
 ter-cells. 
 
 Growth. — They can be cultivated as bacteria are in bouil- 
 lon, but grow best in beer. 
 
 Yeasts are very resistant: cultures have been obtained 
 from material twelve years old and dry as a bone. 
 
 There are several varieties of beer-yeasts, each one giving a 
 
YEASTS AND MOLDS 221 
 
 characteristic taste to the beer. Brewers, by paying special 
 attention to the nutrient media, cultivate yeasts which give 
 to their beers individual flavors. 
 
 Mixed yeast gives rise to a poor quality of beer. 
 
 Saccharomyces Rosaceus; S. Niger; S. Albicans. — 
 These yeasts are found in the air; and instead of producing 
 alcoholic fermentation, they give rise to a pigment in the 
 culture-media. They grow upon gelatin, which they do not 
 liquefy. 
 
 Fig. io8. — ^Yeast-cells i^ X 500; (,r raiiKcl and Pfeiffer). 
 
 Saccharomyces Mycoderma. — This yeast forms a mold- 
 like growth, or skin, on the surface of fermented liquids, but 
 does not cause any fermentation itself. It forms the common 
 "mold" on wine, preserves, and "sauer-kraut." 
 
 Oidium. — ^A form which seems to be the bridge between 
 the yeast and the molds is the oidium. Sometimes it re- 
 sembles the yeasts, sometimes the molds, and often both 
 forms are found in the same culture. Several are patho- 
 genic for man. 
 
222 ESSENTIALS OF BACTERIOLOGY 
 
 Oidium Lactis. — Origin. — In sour milk and butter. 
 
 Form. — The branches or hyphae break up into short, rod- 
 like spores. No sporangium, as in molds. 
 
 Growth. — In milk it appears as a white mold. 
 
 Artificially cultured on gelatin plates, or milk-gelatin plates, 
 it forms satin-like, star-shaped colonies, which slowly liquefy. 
 Under the microscope the form of the fungus is well seen. 
 
 Agar Stroke Culture. — The little stars, very nicely seen at 
 first; then the culture becomes covered with them, causing a 
 smeared layer to appear over the whole surface, with a sour 
 odor. 
 
 Properties. — The milk is not changed in any special way. 
 It is not pathogenic for man or animals. It is found when 
 the milk begins to sour. 
 
 Oidium Albicans (Soor ; Thrush Fungus, Langenbeck, 
 1839). — Origin. — Mucous membrane of the mouth, especi- 
 ally of infants. 
 
 Form. — Taken from the surface of the culture, a form like 
 yeasts; but in the deeper layers, mycelia with hyphae occur. 
 
 Growth. — Not liquefying; snow-white colonies on gelatin 
 plates. 
 
 Stab-culture. — Radiating yellow or white processes spring 
 from the line made by the needle, those near the surface 
 having oval ends. 
 
 Potatoes. — The yeast form develops as thick white colonies. 
 
 Bread-mash. — Snow-white veil over the surface. 
 
 Pathogenesis. — In man the parasitic thrush, or "white 
 mouth," is caused by this fungus. In the white patches the 
 spores and filaments of this microbe can be found. Rabbits 
 receiving an intravenous injection perish in twenty-four to 
 forty-eight hours, the viscera being filled with mycelia. 
 
 Pathogenic Yeasts. — A number of workers have inter- 
 ested themselves in experiments with yeasts in their relation 
 to disease; and under the name of blastomycetes, Sanfelice has 
 grouped yeasts that produce tumors resembling epithelio- 
 mata; and he has tried to prove that the so-called animal 
 parasites found in malignant growths, and variously known 
 
YEASTS AND MOLDS 223 
 
 as coccidia and sporozoa, are yeasts. These are, however, 
 protozoa. 
 
 Blastomycetic Dermatitis or Oidiomycosis. — A skin 
 disease described, in 1894, by Gilchrist, and since then by 
 other writers, is due to a fungus which resembles yeast, and 
 which has been called a blastomyces; but Ophiils and Ricketts 
 term it an oidium, and the former calls the parasite O'idium 
 coccidioides. 
 
 On Lofifler's blood-serum and agar a growth occurs in from 
 three to seven days, small white colonies made up of branch- 
 ing, mold-like forms. On potato the growth is more rapid and 
 shows the yeast forms. 
 
 The disease is slow in process, — ten to twelve years, — 
 leaving much deformity. When generalized, it is fatal. 
 
 Form. — The fungus increases by budding, but in culture- 
 media it may resemble a mold or oidium. 
 
 Pathogenesis. — Small abscesses form in wart-like lesions, 
 which extend over large areas of the skin, becoming later 
 on systemic and invading lungs and kidneys; abscesses and 
 nodules form in these organs. 
 
 Hyphomycetes (True Molds). — Fliigge has made five 
 distinct divisions of molds. It will, however, serve our 
 purpose to classify those to be described under three head- 
 ings: Fenicillium, Mucor, and Aspergillus. 
 
 Penicillium Glaucum. — Origin. — The most widely dis- 
 tributed of all molds, found wherever molds can exist. 
 
 Molds frequently contaminate the cultures by bacteria and 
 culture-media. 
 
 Form. — From the mycelium, h3^h3e spring which divide 
 into basidia (branches), from which tiny , filaments arise 
 (sterigmata), arranged like a brush or tuft. On each sterigma 
 a little bead or conidium forms, which is the spore. In this 
 particular fungus the spores in mass appear green. 
 
 Growth. — It develops only at ordinary temperatures, form- 
 ing thick, grayish-green molds on bread-mash. At first these 
 appear white, but as soon as the spores form, the green pre- 
 dominates. Gelatin is liquefied by it. 
 
224 ESSENTIALS OF BACTERIOLOGY 
 
 Mucor Mucedo. — Next to the Penicillium glaucum, this 
 is the most common mold. Found in horse-dung, in nuts and 
 apples, in bread and potatoes, as a white mold. 
 
 Form. — The mycelium sends out several branches, on one 
 of which a pointed stem is formed which enlarges to form a 
 globular head, a spore-bulb, or sporangium. The spore-bulb 
 is partitioned off into cells in which large oval spores lie. 
 When the spores are ripe, a cap forms around the bulb, the 
 
 Fig. 109. — Penicillium glaucum ( X 500) (Frankel and Pfeiffer). 
 
 walls break down, and the wind scatters the spores, leaving 
 the cap or ''columella^' behind. The rounded sporangium is 
 usually black. 
 
 Growth. — ^Takes place at higher temperatures on acid media. 
 It is not pathogenic. 
 
 Achorion Schonleinii. Trichophyton Tonsurans. 
 Microsporon Furfur. — These three forms are similar to 
 each other in nearly every particular, and resemble in some 
 respects the Oidium lactis, in other ways, the mucors. The 
 
YEASTS AND MOLDS 
 
 225 
 
 first one, Achorion Schdnleinii, was discovered by Schonlein 
 in 1839, in favus, and is now known as the direct cause of this 
 skin disease. 
 
 Origin. — Found in the scaly crusts of favus (Fig. no). 
 
 Form. — Similar to Oidium lactis. 
 
 Growth. — Is very sparse. Agar, at body temperature, 
 two types — waxy, yellowish mass, and downy, white-plush- 
 like covering. 
 
 In milk it is destroyed. 
 
 Pathogenesis. — Causes favus in man, also in animals. 
 
 Trichophyton Tonsurans ("Ring-worm"). — Found, in 
 1854, by Bazin, in tinea. 
 
 Fig, no. — Achorion Schonleinii (after Kaposi). 
 
 Form. — Similar to the achorion or favus fungus. 
 
 Growth. — Somewhat more rapid than the favus, and the 
 gelatin quickly liquefied. Old cultures are of an orange- 
 yellow color. Colonies have a star-shaped form. 
 
 On agar and potato the organism can be cultivated by 
 first treating the infected hairs and scales with potassium 
 hydroxid (dilute solution) ; this liberates the spores and dis- 
 solves some of the bacteria which usually contaminates the 
 culture. Some of the colonies are crateriform. 
 
 Pathogenesis. — Herpes tonsurans and the various tineae are 
 produced by this fungus. 
 IS 
 
226 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 Microsporon Furfur. — Found in tinea or pityriasis versi- 
 color, almost identical with the above; forms dry yellow 
 spots, usually on the chest, in persons suffering from wasting 
 diseases. 
 
 Aspergillus Glaucus. — The aspergillus is a common 
 mold contaminating bacterial cultures. 
 
 Origin. — In saccharine fruits. 
 
 Form. — The hypha has formed upon its further end a bulb, 
 from which pear-shaped sterigmata arise and bear upon their 
 ends the conidia or spores. 
 
 Fig. III. — Aspergillus fumigatus (X soo) (Frankel and Pfeiffer). 
 
 Growth. — Best upon fruit-juices. Non-pathogenic. The 
 mold is green. Aspergillus flavus has the tufts and spores of 
 a yellow color. 
 
 Aspergillus Fumigatus. — Is pathogenic for rabbits when 
 injected into them. At the autopsy their viscera are found 
 filled with the mold. 
 
 Examination of Yeasts and Molds. — Yeasts and molds 
 are best examined in the unstained condition. A small por- 
 tion of the colony rubbed up with a mixture of alcohol and a 
 
YEASTS AND MOLDS 
 
 227 
 
 few drops of liquor ammonia; of this, a little is brought upon 
 the glass slide, covered with a drop of glycerin, and the cover- 
 glass pressed upon it. If the preparation is to be saved, the 
 cover-glass is secured by ringing around the edges with 
 varnish or cement. Yeasts take methylene-blue stain very 
 well. 
 
 Cladothrices and Streptothrices. — The streptothrix and 
 cladothrix groups are classed with the higher bacteria, but 
 their exact status is still undetermined. They may be con- 
 
 Fig. 112. — Cladothrix dichomata from well-water (one-twelfth oil-im- 
 mersion. Fuchsin stain) (author's specimen). 
 
 side red as representing transition forms from the bacteria to 
 the lower fungi. 
 
 Crenothrix Ktihniana (Rabenhorst) . — Long filaments 
 joined at one end; little rod-like bodies form in the filaments, 
 and these break up into spores. 
 
 Zooglea are also formed by means of spores, and these can 
 become so thick as to plug up pipes and carriers of water. 
 They are not injurious to health. 
 
 Cladothrix Dichotoma (Cohn). — ^Very common in dirty 
 waters. The filaments branch out at acute angles, otherwise 
 resembling the crenothrix; accumulations of ocher-colored. 
 
228 ESSENTIALS OF BACTERIOLOGY 
 
 slime, consisting of filaments of this organism, are found in 
 springs and streams. (See Fig. 112.) 
 
 Leptothrix Buccalis. — In the mouth, long filaments or 
 threads resembling bacteria are commonly found. At one 
 end are seen numerous cocci-like bodies, which some regard 
 as spores. A variety of this, or a nearly aUied organism, is 
 the most frequent cause of noma or gangrenous stomatitis. 
 
 With iodin the leptothrix is colored yellow. At one time 
 it was considered the cause of " tartar " on the teeth, and often 
 it fills the crypts of the tonsils, forming there small masses 
 which are difficult to remove. Miller distinguishes three 
 varieties — ^Leptothrix buccalis innominata, maxima, and 
 gigantea. 
 
 Beggiatoa Alba (Vancher). — The miost common of this 
 species. The distinction between this and the preceding 
 species lies in the presence of sulphur granules contained in the 
 structure, and hence they are often found where sulphur or 
 sulphids exist; but where the remains of organic life are de- 
 composing they can also be found. 
 
 Several large spirilla and vibrios live in bog and rain-water, 
 but our space does not suffice to describe them. For the 
 Bacteriologic Examination of Water see p. 325. 
 
 Streptothrix or Cladothrix Actinomyces (Ray-fungus). 
 — Actinomycosis is a disease caused in man and cattle by 
 an organism which is commonly found in grain, particu- 
 larly barley. It is probable that several varieties of the 
 parasite can produce the characteristic lesions. It has been 
 discovered in all countries and in various organs of the body, 
 although its place of election is about the lower jaw, where it 
 tends to form hard, ulcerating abscesses, affecting other 
 organs secondarily. 
 
 Form. — In the granular masses of an abscess cylindric fila- 
 ments are matted together, and radiating outward from this 
 zone are club-shaped branches, as the petals of an aster. 
 (See Fig. 113.) In the center of the granule are numerous 
 cocci-like bodies, and some of the ovoid or club-shaped 
 hyphae lie detached from the clusters. Through cultivation 
 
YEASTS AND MOLDS 229 
 
 it is found that the ovules give rise to filaments, and 
 they then form the ovules again. 
 
 Cultivation. — At 2^'^° C. on glycerin-agar in a period of one 
 to two weeks pointed scales about the size of a millet-seed, 
 center dry and prominent, margins hyaline, composed only of 
 filaments, short and long, massed together, but no clubbed 
 forms. 
 
 The clubs have been considered as spore organs; by 
 
 Fig. 113. — Actinomyces granule crushed beneath a cover-glass, show- 
 ing radial striations in the hyaline masses. Preparation not stained; 
 low magnifying power (Wright and Brown). 
 
 others, they are thought to be encapsulated or thickened 
 filaments. 
 
 Pathogenesis, — When a portion of the growth obtained in 
 eggs is injected into the abdominal cavity of a rabbit, 
 actinomycotic processes develop upon the peritoneum. 
 
 It usually gains access to the living body through a wound 
 in the gum or some caries of the teeth. A new growth is 
 formed, ulceration being first set up. 
 
 The new tissue, composed of round-cells, then undergoes 
 
230 ESSENTIALS OF BACTERIOLOGY 
 
 softening, purulent collections form, and the normal structure 
 
 is destroyed. 
 
 The usual seat is in the maxillary bones, but the fungus has 
 
 been found in the lungs, tonsils, intestines, and various other 
 
 organs in man and cattle. 
 
 Examination. — Well seen in the unstained condition. From 
 
 the pus or scraping a small 
 
 1^ portion is taken and 
 
 ^ squeezed upon the glass 
 
 slide; if calcareous matter 
 
 is present, a drop of nitric 
 
 acid will dissolve this. 
 
 Glycerin will preserve the 
 
 r>%ij preparation. 
 
 'h^^i Staining. — Cover -glass 
 
 : specimens stained best 
 
 by Gram's method. Tissue 
 
 sections should be stained 
 
 , , i as follows: 
 
 J Ziehl's carbol-fuchsin, ten 
 
 ; minutes. Rinse in water. 
 
 Concentrated alcoholic 
 
 "' ' solution of picric acid, five 
 
 minutes. Rinse in water. 
 
 J, ^ , Alcohol, 50 per cent., 
 
 1 * % \ fifteen minutes. Alcohol 
 
 ' m * '®^^' \ absolute, clove-oil, balsam. 
 
 \^^ --^ J The rays stained red, the 
 
 17- "" c. . .u • iiT T*^ tissue yellow. 
 
 Fig. 114, — Streptothrix Madurae o* 4. .n. • -kit a 
 
 in a section of diseased tissue (Vin- btreptothnx Madurae 
 
 cent). (Vincent). — Origin. — 
 
 Found in the disease known 
 as Madura foot, or mycetoma, an ulceration affecting the 
 feet, especially of individuals living in the tropics. Two 
 varieties, the pale and the black, have been described. 
 
 Form. — Branched filaments resembling the actinomyces 
 streptothrix. In the mycelia spores are seen (Fig. 114). 
 
 1 j * 
 
 
 
 -A '. .' 
 
 \ 
 
 ' B -^ W 
 
 ^<, " ^ 
 
 
 &ij^^'-t' 
 
 
YEASTS AND MOLDS 231 
 
 Cultivation. — In liquid media containing vegetable infu- 
 sions growth occurs best. Temperature of 37° C. most 
 suited. The colonies near the surface become colored red. 
 
 Agar. — Glazed colonies, at first colorless, then rose-colored, 
 about the size of a pea, with the central part umbilicated and 
 pale. Gradually the rose color fades. 
 
 Acid Potato. — ^A slow and meager growth. 
 
 Pathogenesis. — Only local reaction has been caused by 
 inoculation in animals. In man the disease usually follows a 
 slight injury and attacks the leg or foot, slowly forming a 
 nodular growth, which in the course of months or a year 
 begins to soften and ulcerate, and with the seropus are dis- 
 charged numerous little granules, some black, some pink, 
 containing mycelia. The limb becomes much deformed, the 
 tissue vascularized, and the degenerated area filled with the 
 streptothrix filaments. 
 
 Staining. — ^The organism itself stained with ordinary 
 stains. Gram's method for the tissue. 
 
 Nocardia (Streptothrix) Farcinica.(Nocard) ; Bovine 
 Farcin du Boeuf . — Origin. — A disease affecting cattle, and 
 giving rise to tubercle-like lesions in the lungs, liver, and 
 spleen. Common in France. 
 
 Form. — Small interwoven mass of threads arranged in 
 tufts found in the centers of the tubercles. 
 
 Culture. — ^At body-temperature in various media. 
 
 Bouillon. — Colorless masses, irregular in size and shape. 
 
 Agar and Gelatin. — Small, rounded, opaque colonies, 
 thicker at the periphery. 
 
 Potato. — Rapid growth of pale-yellow, dry scales, consist- 
 ing of many spores. 
 
 Pathogenesis. — Pure cultures introduced into the perito- 
 neum of guinea-pigs give rise in nine to twenty days to 
 tubercle-like lesions. Subcutaneous injections cause abscesses 
 with secondary involvement of the lymphatics, ending in 
 recovery. Dogs, horses, and rabbits are immune. 
 
 Staining. — Wright's double stain for tissues; also Gram's. 
 
 Plant Diseases due to Bacteria. — There are a great 
 
232 ESSENTIALS OE BACTERIOLOGY 
 
 variety of blights, rots, and new-growths, such as galls attack- 
 ing plants, which are seemingly due to bacteria. About 30 
 varieties have so far been more or less accurately described, 
 but only a few of the organisms have been definitely asso- 
 ciated with the disease. The pear blight is due to Bacillus 
 amylovorus. Crown gall, which affects a great many plants 
 and trees, is supposed to be due to Bacterium tumefaciens; 
 the black rot of cabbage to a pseudomonas. There is much 
 left to be done to place this part of bacteriology on a par 
 with that devoted to animals and man. 
 
 CHAPTER XXXI 
 EXAMINATION OF AIR, SOIL, AND WATER 
 
 Air. — Many germs are constantly found in the atmosphere 
 about us. Bacteria unaided do not rise into the air and fly 
 about; they usually become mixed with small particles of dirt 
 or dust and are moved with the wind. The more dust, the 
 more bacteria, and, therefore, the air in summer contains a 
 greater number than the air in winter, and all the other dif- 
 ferences can be attributed to the greater or less quantity of 
 dust and velocity of the wind. 
 
 By the use of balloons, living bacteria have been found at 
 an altitude of 4000 meters. 
 
 Methods of Examination. — ^The simplest method is to 
 expose a Petri dish with gelatin or agar in a dust-laden atmos- 
 phere or in the place to be examined. In the course of twenty- 
 four to forty-eight hours colonies will form wherever a 
 germ has fallen. But this method will not give any accurate 
 results in regard to the number of bacteria in a given space; 
 for such purposes somewhat more complicated methods are 
 used, so that a definite amount of air can come in contact 
 with the nutrient medium at a certain regulated rate of speed. 
 
EXAMINATION 01 AIR, SOIL, AND WATER 
 
 233 
 
 This form of analysis, however, has not yielded any very 
 practical results, and is not much resorted to. 
 
 Hesse's Method. — Hesse's method requires an apparatus 
 called an aero scope, which, by means of siphoning bottles 
 {aspirator), sucks air through 
 a cylinder lined with gelatin, tlrPh 
 
 and by regulating the rate of ^J/- 
 
 flow an approximate idea of ^i3l 
 
 the number of bacteria per 
 liter of air can be obtained. 
 A less complicated method is 
 known as Petri's method. 
 
 Fig. 115. — Petri's sand-filter for 
 air-examination (McFarland). 
 
 Fig. 116. — Sedgwick's expanded 
 tube for air - examination (Mc- 
 Farland). 
 
 Sand is sterilized by heating to redness, and while still 
 warm placed in test-tubes, which are then plugged. 
 
234 ESSENTIALS OF BACTERIOLOGY 
 
 The tube and its contents, the ends having first been 
 plugged with cotton, are sterilized in a hot-air oven at 
 150° c. 
 
 One end of the tube is then fitted with a rubber cork 
 through which passes a glass tube, which is connected with 
 an aspirator (a hand-pump with a known capacity). 
 
 If 100 liters of air pass through the tube in fifteen min- 
 utes, the germs should all be arrested in the first sand-filter. 
 And when the filters are removed, each filter for itself, and 
 thoroughly mixed with gelatin, there should be no colonies 
 developed from the second filter, i. e., the one nearest the 
 aspirator. 
 
 Sedgwick-Tucker Method. — A special form of tube is 
 used, called an aerobioscope. It consists of a neck 2.5 cm. in 
 length, an expanded portion 15 cm. long, and a long narrow 
 tube of 15 cm. After sterilization the tube is partly filled 
 with granulated sugar, which is the filtering material. By 
 means of a vacuum gage and an air-pump, or ordinary aspirat- 
 ing bottles, the volume of air passing through the apparatus 
 can be determined. After the air has been passed through, 
 the sugar is gently shaken from the narrow tube into the 
 expanded portion, and 20 c.c. of liquefied gelatin is poured in. 
 The sugar dissolves, and the mixture is then rolled on the 
 inner side of the glass as an Esmarch tube. This part of the 
 apparatus is divided into squares to make the counting of 
 colonies easy. The aerobioscope is very highly recommended. 
 
 Varieties Found in Air. — The only pathogenic bacteria 
 found with any constancy are the Staphylococcus aureus and 
 citreus; but any bacterium can, through accident, be lifted 
 into the atmosphere, and under certain conditions may be 
 always present — the Bacillus tuberculosis, for example, in 
 rooms where consumptives are living. 
 
 Typhoid fever, influenza, pneumonia, and diphtheria may 
 be conveyed through the air by the cough and expectora- 
 tion of affected persons. 
 
 N on- pathogenic. — The micrococci predominate. Sarcinae, 
 yeasts, and molds constantly contaminate cultures. 
 
EXAMINATION OF AIR, SOIL, AND WATER 23$ 
 
 In the ordinary habitations the average number of germs 
 to the liter of air does not exceed five. 
 
 Around water-closets, where one would imagine a great 
 number to exist, but few will be found, owing to the undis- 
 turbed condition of the air. 
 
 Sewer air seldom, if ever, contains bacteria, and neither 
 typhoid fever, malaria, nor diphtheria has ever been traced to 
 the escape of so-called sewer-gas. 
 
 Examination of Water. — The bacteriologic examination 
 of w^ater is today of as much importance as the chemical 
 analysis, and must go hand in hand with it. 
 
 A water containing thousands of germs to the cubic centi- 
 meter is far less dangerous than one containing but two 
 germs, if one of these two be a typhoid bacillus. It is not the 
 number that proves dangerous, it is the kind. 
 
 If a natural water contains more than 500 germs to the 
 cubic centimeter, it were well to examine its source, and 
 consider it with suspicion. 
 
 As a means of diagnosis the examination is of but little use. 
 An epidemic of typhoid fever occurs, the water is suspected, 
 an examination is undertaken; but the period of incubation 
 and the days passed before the water is analyzed have given 
 the typhoid germs, if any had been present, ample time to 
 disappear, since in water that contains other bacteria they live 
 a few days only. Again, the water tested one day may be 
 entirely free and the next day contain a great number, and 
 before the typhoid germ can be proved to be present in that 
 particular water the epidemic may be past. Human sewage 
 contamination is determined by finding the colon bacillus, and 
 if this is found in the course of an epidemic of typhoid the 
 water containing it may well be suspected as being the 
 cause. 
 
 Purity of Waters. — The purest water we have is the 
 natural spring-water — water that has slowly filtered its way 
 through various layers of gravel and sand and comes finally 
 clear and sparkling from the ground. It is free from bac- 
 teria, but let such a water stand walled up in cisterns or 
 
236 ESSENTIALS OF BACTERIOLOGY 
 
 wells, or run through the wood, gathering the w^ashings from 
 pastures and farm lands, it becomes, as surface water, open 
 to all sorts of impurities, and the bacterial nature of it 
 changes every moment. 
 
 Artesian or Driven Well. — The driven well will secure to 
 a certain extent a pure water. It is the only form of well or 
 cistern that will insure this, since the water does not become 
 stagnant in it; but it m^ay connect with an outhouse — the soil 
 being very loose — and thus bacteria and refuse water find 
 their way into the wtII. The casing may not be water-tight 
 and surface water can be sucked in. 
 
 Filtered Water. — Dangerous as surface water is, the 
 greater quantity used is such, the inhabitants of larger towns 
 and cities using chiefly the rivers and other large waters which 
 course near them for drinking purposes. A purification or 
 filtration can, to a certain extent, render these waters 
 harmless. 
 
 Filtration is carried on on a large scale in the water-works 
 of cities and towns, and bacteriologic examJnation is here of 
 great service to determine if a water which has been filtered 
 and may have a very clear appearance, and give no harmful 
 chemical reaction, is entirely free, or nearly so, from germs; 
 in other words, if the filter is a germ-filter or not; daily tests 
 are necessary in order to insure safety, and if it is performing 
 this function regularly, a good filter plant should show 99.8 
 per cent, efficiency, removing nearly all the bacteria. 
 
 Filter Materials. — When waters are muddy or when rapid 
 filtration is wanted, mechanical filters are employed. The 
 water is first treated with coagulants, like alum, w^hich forms 
 a flocculent precipitate and carries down with the suspended 
 matter much of the bacterial content. This is then filtered 
 through sand and gravel. Sedimentation and filtering 
 slowly through gravel and sand is known as the slow process; 
 the other as the rapid, filtration. 
 
 Charcoal sponge and asbestos, the materials formerly in 
 use, are objectionable because germs readily develop on them 
 and clog them, so that they require frequent renewal. In 
 
EXAMINATION OF AIR, SOIL, AND WATER 237 
 
 very large filters, sand and gravel give the best results; the 
 number of bacteria in a cubic centimeter is reduced to forty or 
 fifty and kept at that number. This is a very pure water for 
 a city water, though, as we stated before, not a safe one, for 
 among those forty germs very dangerous ones may be found. 
 It is then necessary for the users to refilter the water, before 
 drinking it, through a material which will not allow any 
 germs to pass, or, in the presence of an epidemic, to boil all 
 water used for drinking purposes. 
 
 Fig. 117.— Flask fitted with porcelain bougie for filtering large quantities 
 
 of fluid. 
 
 Pasteur-Chamberland Filter. — This very perfect filter 
 consists of a piece of polished porcelain in the form of a 
 cylinder closed at one end and pointed at the other. It is 
 placed in another cylinder of glass or rubber, and the pointed 
 portion connected with a bottle containing the water, or 
 directly with the faucet of the water-pipe. The water courses 
 through the porcelain very slowly and comes out nearly free 
 from germs; pipe-clay, bisque, infusorial earth, and kaolin are 
 also good filters. The only disadvantage is the long time it 
 takes for the water to pass through. Pressure in the form 
 
238 ESSENTIALS OF BACTERIOLOGY 
 
 of an aspirator or air-pump is used to accelerate the pas- 
 sage. 
 
 These porcelain cylinders can easily be sterilized and the 
 pores washed out. 
 
 All the cylinders or bougies are not germ proof, so that they 
 must be tested, and most of them must be cleaned every 
 fourth day. In recent years a number of organisms have 
 been suspected of being so minute as to pass through a 
 Berkefeld or Pasteur filter. At least the poison or virus is 
 filterable, and, therefore, we cannot regard these as abso- 
 lutely safe. 
 
 Boiling as a Means of Purifying. — The only safe measure 
 in times of epidemics and with waters of unknown composi- 
 tion is boiling, not only of the drinking water, but all water 
 used for domestic purposes; and this should especially be 
 done in times of typhoid and cholera epidemics. 
 
 Varieties Found in Water. — The usual kinds found are 
 non-pathogenic, but, as is well known, typhoid, cholera, and 
 dysentery are principally spread through drinking-water, 
 and many other germs may find their way into the water. 
 Some of the common varieties give rise to fluorescence or 
 produce pigment. 
 
 Eisenberg gives 100 different varieties as ordinarily found. 
 Other intestinal diseases besides those mentioned above are 
 supposed to be water borne. Diarrheas in epidemic form 
 may come from suddenly changing a public supply, and 
 the presence of the Bacillus coli communis means sewage 
 contamination or fecal contamination; such contamination 
 may come from the droppings of birds or other animals and 
 need not necessarily imply human sewage, but 10 colon 
 bacilli in i c.c. water is a serious pollution. Ice supplies 
 require the same supervision as water supplies, for many 
 bacteria, like the typhoid bacillus, retain their vitality for 
 weeks after freezing. 
 
 Method of Examination. — (After that suggested by the 
 American Public Health Association, igi2 report.) — Since 
 the germs rapidly multiply in stagnant water, an examina- 
 
EXAMINATION OF AIR, SOIL, AND WATER 239 
 
 tion must not be delayed longer than possible after the 
 water has been collected. Every precaution must be taken 
 in the way of cleanliness to prevent contamination; sterilized 
 flasks with glass stoppers, pipets, and plugs must be at hand, 
 glassware sterilized in autoclave at 120° C. for fifteen minutes, 
 or dry heat at 160° C. for one hour, and the gelatin tubes or 
 agar dishes be inoculated on the spot. If this cannot be done, 
 the sample should be packed in ice until it arrives at the 
 laboratory. If it is necessary to send the sample by rail, 
 the bottle containing the sample should be wrapped in steril- 
 ized cloth, or the neck covered with tinfoil and the bottles 
 placed in tin boxes (about 4 ounces — 100 c.c. — is sufficient 
 for bacterial analysis), and then packed in cotton or paper 
 to prevent breakage and surrounded by plenty of ice until 
 it reaches its destination. As soon as it arrives at the lab- 
 oratory the sample is placed in a sterilized glass flask, and 
 the flask then closed with a sterile cotton plug. A sterilized 
 pipet is then dipped into the flask, and i c.c. of the water 
 withdrawn and added to a Petri dish. To a second dish, a 
 dilution of i c.c. of the sample with sterile distilled water is 
 added, and other dilutions made if desired. To each plate 10 
 c.c. of standard agar at a temperature of 40° C. is added. 
 Mix the water and media thoroughly by tipping the dish 
 back and forth, and place in incubator at 37° C. for twenty- 
 four hours. The incubator should be in a dark, well-venti- 
 lated, and moist place. Then count all the colonies present 
 on each plate, which will give the number per cubic centi- 
 meter. 
 
 Water that is very rich in germs requires dilution with 
 sterilized water fifty to one hundred times. Fewer colonies 
 will be found on agar than on gelatin, even at the same tem- 
 perature. 
 
 Special Media and Preparation. — In the preparation of 
 media for water analysis, sodium chlorid must not be used. 
 The reaction of most culture-media should be -j- 1 per cent, 
 to phenolphthalein. 
 
 Sugar broths should be neutral, and must be sterilized care- 
 
240 ESSENTIALS OF BACTERIOLOGY 
 
 fully in steam and not overheated, so as to prevent inversion 
 of the sugar. 
 Examination for Bacillus Coli and Sewage Bacteria. 
 
 — Instead of examining for typhoid bacilli, sewage contamina- 
 tion is best indicated by the presence of the colon group of 
 organisms, although their abundance rather than mere pres- 
 ence is to be considered. There are many closely related 
 bacteria which give reactions similar to the Bacillus coli, but 
 they are chiefly of fecal origin, and for practical purposes 
 they can be included in the colon group. 
 
 General Characteristics of Colon Group. — i. Fermentation of 
 dextrose and lactose with gas-production. 2. Short bacillus, 
 non-liquefying, Gram negative. 
 
 The committee of the Public Health Association recom- 
 mends the following procedure: 
 
 Two Methods. — Method a. — ^Applicable for sewage waters. 
 Preparation of an agar plate with a known volume of w^ater, 
 using lactose litmus-agar and incubating at 40° C. Bacillus 
 coli will show its presence by red colonies (acid fermentation 
 of the sugar) ; further testing is then needed to fully identify. 
 Not all red colonies Bacillus coli. 
 
 Method h. — Cultivation, at 40° C, of a measured quantity 
 of water in a fermentation tube containing a sugar broth. 
 If gas appears, a portion of the liquid is plated as in method a. 
 
 Additional Details. — If in twenty-four hours no red colonies 
 appear in the agar-lactose litmus Petri dishes. Bacillus coli 
 is considered absent, providing the sample was a polluted 
 one, so that the bacilli, if present, would be in a concentrated 
 form. Only i or 2 c.c. of water can be used, because the 
 ordinary water-bacteria spread rapidly and contaminate the 
 other bacteria. 
 
 If acid-forming colonies are found, five or six are fished for 
 subcultures on slanted agar, in fermentation tubes, milk, 
 gelatin, peptone solution, and nitrate broth. 
 
 If the water is not strongly contaminated, an imderground 
 water, for instance, or a mountain stream, the better way is 
 to inoculate two or three lactose or dextrose bouillon fermen- 
 
EXAMINATION OF AIR, SOIL, AND WATER 24I 
 
 taticn tubes and place in an incubator at 40° C. Note the 
 presence of gas, if any, at the end of twelve, twenty-four, 
 thirty-six, and forty-eight hours. // no gas forms, sewage 
 bacteria are absent. 
 
 If gas forms, plate at once a portion of the sediment as 
 above on lactose litmus-agar. Test the other fermentation 
 tubes for acidity, and the nature of the gas, whether any, and 
 how much is absorbed by a 2 per cent, solution of sodium 
 hydroxid. Bacillus colt should produce between jo and yo 
 per cent, of gas, of which about one-third is CO2 and is ab- 
 sorbed by the alkali; the remainder is hydrogen. The other 
 broth culture can be tested for the presence or absence of 
 unfermented sugar by Fehling's solution. 
 
 Diagnostic Points of Colon Bacillus. — Microscopic. — 
 Non-spore-bearing motile bacillus. 
 
 Gelatin. — Non-liquefactive. 
 
 Dextrose Broth. — Fifty per cent, gas; one- third absorbed, 
 CO2; two-thirds, hydrogen. 
 
 Milk (litmus) coagulated in forty-eight hours and rendered 
 acid; litmus colored red. 
 
 Peptone Solution. — Production of Indol. — (A peptone solu- 
 tion tube is inoculated with the culture and kept together with 
 a control four days at 37° C. Then 2 drops of concentrated 
 sulphuric acid and i centimeter of a 0.0 1 per cent, solution of 
 sodium nitrate are added. The appearance of a pink color 
 at the end of thrity minutes denotes the presence of indol.) 
 
 Presumptive Test. — If a water from a well or spring pro- 
 duces gas in the sugar broth and forms acid colonies on litmus- 
 lactose agar, the presumption is strong that there is sewage 
 contamination. If gas-production continues in a series of 
 samples carefully collected for several days or weeks, there 
 can be no doubt of a contamination, and especially if the well 
 or spring is protected from surface water. Algae w^hich grow 
 in service pipes, reservoirs, and deep wells may give rise to 
 non-acid gas fermentation, but all well-water that, without 
 further testing, . forms acid colonies on litmus-agar lactose 
 plates and ferments sugar broth, is open to suspicion, and if 
 16 
 
242 ESSENTIALS OF BACTERIOLOGY 
 
 there is evidence of the presence of typhoid fever or diarrheal 
 diseases, the water should be boiled and subjected to careful 
 analysis daily. There may be serious contamination and 
 the chemical tests show no appreciable increase in the chlorids. 
 
 Bile Media. — In recent years bile salts or fresh bile mixed 
 with lactose have been extensively used, as the bile inhibits 
 the action of many bacteria and allows the colon and ty- 
 phoid group to develop readily. 
 
 The Jackson bile media (see formula for media. Chap. X) 
 is placed in fermentation tubes of 40 c.c. capacity, and in- 
 oculated with varying proportions of the water to be tested. 
 Incubated at 37° C., and presence of gas looked for in twelve 
 hours, twenty-four hours, and forty-eight hours, and the 
 quantity and time noted. 
 
 In sewage and contaminated waters the lactose-bile gives 
 better results than any other medimji. 
 
 The Presumptive Test (Modified). — Plant yq-, i, and 10 
 c.c. of water into liver broth tubes. Transplant from these 
 into lactose bile in six and twelve hours. By using implan- 
 tations of both lactose bile and liver broth, and then trans- 
 planting the liver-broth cultures into other lactose bile, we 
 have in the original bile the vigorous Bacillus coli. The liver- 
 broth dilutions give all the gas formers, strong and weak, 
 and the difference between the original and the transplanted 
 gives an idea of the attenuated Bacillus coli present. Thus 
 all the gas formers are cultured. 
 
 Bacillus Typhosus. — By the use of bile media and other 
 special media as enrichment and then transplanting on 
 Hesse Agar, Conradi-Drigalski, or Endo media, the Bacillus 
 typhosus are increased in number and the possibilities of 
 diagnosing them made much easier. The Widal test is 
 used to differentiate Bacillus typhosus from Bacillus coli. 
 
 Quantitative Tests. — The number of acid colonies in i c.c. 
 and in 5 c.c. of water is taken as a measure of pollution, to- 
 gether with the total number of colonies of all bacteria present. 
 Thus in i c.c. on the gelatin plate at 20° C. there may be 
 
EXAMINATION OF AIR, SOIL, AND WATER 243 
 
 fifty colonies; on the agar plate at 37° C. ten colonies, five of 
 which were acid-formers, or presumably Bacillus coli. 
 
 To count the colonies which develop upon the plates, a 
 special apparatus has been designed, known as — 
 
 WolfhiigeVs Counter. — A glass plate divided into squares, 
 each a centimeter large, and some of these subdivided. This 
 plate is placed above the dish with the colonies, and the num- 
 ber in several quadrants taken, a lens being used to see the 
 smaller ones. 
 
 It is best to count all the colonies on the plate or dish. 
 
 Bacterial Treatment of Sewage. — Where sewage is to be 
 rendered innocuous before being allowed to flow into streams, 
 the process of nature has been imitated by the construction 
 of septic tanks in which the sewage remains excluded from 
 the air and subject to the action of the anaerobic bacteria 
 present in the sewage. The organic nitrogen is reduced, and 
 compounds of hydrogen and sulphur are formed. The 
 effluent is then filtered through coke-beds, w^here the aerobic 
 bacteria assist in further purification and over sand filters, or 
 exposed to the air on contact beds. No method of sewage 
 purification is very practical or safe. Pure water should not 
 depend oh the efficiency of sewage filtration, but should be 
 obtained from a reasonably pure source. 
 
 Sewage is also treated by sedimentation with alum and 
 filtration of the effluent over larger beds, or allowed to per- 
 colate through the soil, which is thereby enriched and utilized 
 for agriculture. It is also dried and sold in a compressed 
 form for fertilizer. 
 
 The Examination of the Soil. — The upper layers of the 
 soil contain a great many bacteria, but because of the diffi- 
 culty in analyzing the same, the results are neither accurate 
 nor constant. The principal trouble lies in the mixing of the 
 earth with the nutrient medium ; little particles of ground will 
 cling to the walls of the tube, or be embedded in the gelatin, 
 and may contain within them myriads of bacteria. As with 
 water, the soil must be examined immediately or very soon 
 after it is collected, the bacteria rapidly multiplying in it. 
 
244 ESSENTIALS OF BACTERIOLOGY 
 
 When the deeper layers are to be examined, some precau- 
 tions must be taken to avoid contamination with the other 
 portions of the soil. One method, very laborious and not 
 often practical, is to dig a hole near the spot to be examined 
 and take the earth from the sides of this excavation. 
 
 Frankel's Borer. — Frankel has devised a small apparatus 
 in the form of a borer, which contains near its lower end a 
 small cavity, which can be closed up by turning the handle, 
 or opened by turning in the opposite direction. 
 
 It is introduced with the cavity closed, and when it is at 
 the desired depth, the handle is turned, the earth enters the 
 cavity, the handle again turned, incloses it completely, and 
 the borer is then withdrawn. 
 
 The earth can then be mixed with the culture-medium in a 
 tube, and this gelatin then rolled on the walls of the tube after 
 the manner of Esmarch, or it can be poured upon a plate, 
 and the colonies developed therein. 
 
 Another method is to wash the earth with sterilized water, 
 and the water then mixed with the culture-medium, as many 
 of the germs are taken up by the water. 
 
 The roll-cultures of Esmarch give the best results, many of 
 the varieties usually found being anaerobic. 
 
 Animals inoculated with the soil around Berlin are said to 
 die almost always of malignant edema, and the soil of other 
 towns produces tetanus. Many of the germs found are nitro- 
 gen formers and play a great role in the economy of the soil. 
 
 Bacteria and Soil Fertility. — Nitrifying organisms are 
 found in the superficial layers of the earth. Organic matters 
 found in sewage and in the fecal evacuations of animals form 
 the basis for their activity, whereby nitrates, ammonias, and 
 nitric acid result. The nitrogen necessary for the growing 
 plant is thus produced. The nitromonas of Winogradsky 
 belongs to this group. The soil tends to destroy ordinary 
 disease-bacteria in a short time, but spores may remain dor- 
 mant for a number of years, as, for instance, the spores of 
 anthrax. 
 
 As bacteria are instrumental in transforming organic 
 
EXAMINATION OP AIR, SOIL, AND WATER 245 
 
 matter, their influence in making the soil more useful for 
 agricultural purposes has been the subject of much research. 
 The richer the soil, the greater the number of bacteria. 
 Most bacteria are found under the surface between i and 
 2 inches. 
 
 The rod-shaped organisms predominate. 
 
 From an agricultural standpoint the most important 
 bacteria are those capable of liberating nitrogen and break- 
 ing up protein substance. 
 
 Carbohydrates are added to soil by manure, by the growth 
 of grasses and crops, and these are decomposed by bacteria 
 and methane and hydrogen produced. 
 
 Ammonia Production, — Most soil bacteria can produce 
 ammonia; a few, the so-called urea bacteria, are capable of 
 rapid transformation — nitrification. 
 
 Ammonia, oxidized into nitrites or nitrates, is possible 
 through the agency of a group of micro-organisms given 
 especial prominence by Winogradski. Moisture conditions 
 and the presence of lime and mineral carbonates influence the 
 nitrifying organisms. 
 
 The character of the growing crop affects the accumulation 
 of nitrates; legumes assimilate nitrogen more rapidly than 
 non-legumes. 
 
 Denitrification. — The reduction of nitrates to nitrites and 
 ammonia is accomplished by a number of bacteria. Nitrate 
 reduction is of little importance in the field, but under exces- 
 sive manuring it may become so. Bacteria play the impor- 
 tant part of making available to vegetation the nitrogen of 
 the air. 
 
 Azofication. — Certain bacteria can fix atmospheric nitrogen 
 and make it serve, but the energy necessary must be fur- 
 nished by carbohydrates. 
 
 The enrichment of the soil by the growth of legumes has 
 been shown to be due to the bacteria contained in the nodules 
 or tubercles of the plant, these bacteria having the power to 
 fix nitrogen and deriving their energy from the plant juices, 
 
246 ESSENTIALS OF BACTERIOLOGY 
 
 the plants in turn utilizing the nitrogen compounds created 
 by the bacteria. 
 
 Soil Inoculation. — Artificial help to soils deficient in nitro- 
 gen-fixing organisms has been the subject of much experiment. 
 
 Nitragin. — Pure cultures of legume bacteria under the 
 above name have been tried. Dried cultures under the name 
 of nitro-bacterine have likewise been marketed, but neither 
 of these methods has proved valuable; the matter is still in 
 the experimental stage. 
 
 CHAPTER XXXII 
 BACTERIA IN MILK AND FOOD 
 
 The Bacteria of Milk. — Milk as secreted is sterile, but 
 at every step in its passage from the cow to the consumer it 
 is liable to contamination. Even the lower portion of th6 
 teat is a source of infection, owing to the presence of stag- 
 nated milk from the former milking, and, as milk ready for 
 consumption usually contains thousands to millions of bac- 
 teria to the cubic centimeter, sterilization or pasteurization 
 and supervision of the dairies should always be enforced for 
 milk used for infant feeding. 
 
 A standard milk should he free from pus and should not 
 contain more than 10,000 bacteria to thz cubic centimeter. 
 
 Leukocytes are normally found in milk, and only when 
 their number exceeds one million and pyogenic organisms are 
 also present can pus be said to exist. Pasteurization of un- 
 clean milk sometimes renders it more dangerous as a food 
 than untreated milk, because, by preventing the action of 
 lactic-acid formers, other bacteria are permitted to develop 
 and produce pathogenic toxins. 
 
 Pure Milk. — A pure milk is one that is obtained from a 
 healthy cow, well groomed, in a clean room, by a healthy, 
 clean person, in clean cans or bottles, and transported to the 
 
BACTERIA IN MILK AND FOOD 247 
 
 consumer in as short time as possible without further hand- 
 ling, keeping the container in the mean time at a low tern- 
 perature and protected from the air. Such treatment is safer 
 than any form of sterilization. 
 
 Classification of Milk. — {Abstract of resolutions adopted 
 by the Commission on Milk Standards at Richmond, Va., 
 May 2-j, 191 3.) : 
 
 Milk shall be divided into three grades, which shall be the 
 same for both large and small cities and towns. 
 
 Grade A. — Raw milk. — Milk of this class shall come from 
 cows free from disease as determined by tuberculin tests and 
 physical examinations by a qualified veterinarian, and shall 
 be produced and handled by employees free from disease 
 as determined by medical inspection of a qualified physician, 
 under sanitary conditions such that the bacteria count shall 
 not exceed 100,000 per cubic centimeter at the time of de- 
 livery to the consumer. It is recommended that dairies 
 from which this supply is obtained shall score at. least 80 on 
 the United States Bureau of Animal Industry score card. 
 
 Pasteurized Milk. — Milk of this class shall come from cows 
 frefe from disease as determined by physical examinations 
 by a qualified veterinarian and shall be produced and handled 
 imder sanitary conditions such that the bacteria count at no 
 time exceeds 200,000 per cubic centimeter. All milk of this 
 class shall be pasteurized under official supervision, and the 
 bacteria count shall not exceed 10,000 per cubic centimeter 
 at the time of delivery to the consumer. It is recommended 
 that dairies from which this supply is obtained should score 
 65 on the United States Bureau of Animal Industry score 
 card. 
 
 The above represents only the minimum standards under 
 which milk may be classified in grade A. 
 
 Grade B. — Milk of this class shall come from cows free 
 from disease, as determined by physical examinations, of 
 which one each year shall be by a qualified veterinarian, and 
 shall be produced and handled under sanitary conditions 
 such that the bacteria count at no time exceeds 1,000,000 per 
 
248 ESSENTIALS OF BACTERIOLOGY 
 
 cubic centimeter. All milk of this class shall be pasteurized 
 under official supervision, and the bacteria count shall not 
 exceed 50,000 per cubic centimeter when delivered to the 
 consumer. 
 
 It is recommended that dairies producing grade B milk 
 should be scored and that the health departments or the 
 controlling departments, whatever they may be, strive to 
 bring these scores up as rapidly as possible. 
 
 Grade C. — Milk of this class shall come from cow^s free 
 from disease as determined by physical examinations and 
 shall include all milk that is produced under conditions such 
 that the bacteria count is in excess of 1,000,000 per cubic 
 centimeter. 
 
 All milk of this class shall be pasteurized, or heated to a 
 higher temperature, and shall contain less than 50,000 bac- 
 teria per cubic centimeter when delivered to the customer. 
 It is recommended that this milk be used for cooking or manu- 
 facturing purposes only. 
 
 Whenever any large city or community finds it necessary, 
 on account of the length of haul or other peculiar conditions, 
 to allow the sale of grade C milk, its sale shall be surrounded 
 by safeguards such as to insure the restriction of its use to 
 cooking and manufacturing purposes. 
 
 Classification of Cream.— Cream should be classified 
 in the same grades as milk, in accordance with the require- 
 ments for the grades of milk, excepting the bacterial standards, 
 which in 20 per cent, cream shall not exceed five times the 
 bacterial standard allowed in the grade of milk. 
 
 Ice Cream. — Made and handled under sanitary conditions 
 it contains mostly Bacillus lactis acidi type, not dangerous; 
 but if made from milk and cream containing putrefactive 
 bacteria, freezing wall not prevent further growlh and bac- 
 terial poisons may be developed, causing sickness and death. 
 An examination of specimens collected gave as the lowest 
 count 50,000 bacteria per cubic centimeter, and the highest 
 150,000,000 per cubic centimeter. 
 
BACTERIA IN MILK AND FOOD 249 
 
 SOME BACTERIA FOUND IN MILK 
 
 Fermentation of Milk. — Lactic Acid Lactose. — Fermenta- 
 tion of miik is due to the conversion of milk-sugar into lactic 
 acid. This can be accomplished by a number of different 
 bacteria, such as Bacillus coli, streptococci and staphylo- 
 cocci, which are apt to be present about the dairy. The 
 lactic-acid bacteria are commonly present in sour milk, and 
 are chiefly concerned with fermentation. There are several 
 varieties, but principally three groups. 
 
 The first group, like the Streptococcus pyogenes, is called 
 the Bacterium lactis acidi group. Milk is curdled within 
 twenty-four hours without gas-formation. The milk has a 
 mild acid taste and agreeable odor. The curd is even, a 
 true lactic fermentation. 
 
 The second group resembles the Bacillus coli — Bacillus 
 lactis aerogenes. Indol and hydrogen sulphid often formed. 
 Milk curdles, but the curd shrinks. Not easUy emulsified. 
 This fermentation undesirable. 
 
 The third group, true lactic bacteria — Bacterium bulgari- 
 cum; exclusively lactic acid; curd easily broken. 
 
 Bacterium Acidi Lactici (Hiippe) . — Belongs to the same 
 group as the Bacillus coli conununis (see page 134). 
 
 Synonyms. — Bacillus acidi lactici; B. lactis aerogenes 
 (Escherich), 
 
 Origin. — ^In sour milk. 
 
 Form. — Short thick rods, nearly as broad as they are long, 
 usually in pairs, resembling B. coli. 
 
 Properties. — Immotile. Does not liquefy gelatin. Breaks 
 up the sugar of milk into lactic acid and carbonic acid gas, 
 the casein being thereby precipitated. The fermentation of 
 milk produced by this group is offensive; taste undesirable. 
 Curd is firm. 
 
 Stain. — Does not take Gram. 
 
 Growth. — Rapid and abundant; is facultative anaerobic. 
 Grows at 10° C. Grows in all media and in absence of car- 
 bohydrates. 
 
 Stab-culture. — A thick dry crust with cracks in it forms on 
 the surface after a couple of weeks. 
 
250 ESSENTIALS OF BACTERIOLOGY 
 
 Attenuation. — If grown through successive generations, 
 it loses power to produce fermentation. 
 
 Streptococcus Acidi Lactici (Grotenfeld) (1889). — 
 Widely distributed in nature. 
 
 Synonyms. — Bacterium lactis acidi; Bact. Giintheri. 
 
 Origin. — In sour milk. 
 
 Appearance. — Very short cells, often as large as oval cocci, 
 in pairs or small chains, outer ends pointed. 
 
 Properties. — Immotile. Stain with Gram. Growth best 
 at 3o°-35° C. 
 
 Growth. — Facultative anaerobic. Delicate, opaque, re- 
 sembling dewdrops. Bouillon containing glucose grows 
 cloudy. Gelatin not liquefied. Milk coagulated. Strong 
 acid reaction. Curd is soft and easily mixed within twenty- 
 four hours. Gas is not formed. 
 
 In lactose-agar stab no surface growth, but all along the 
 line. 
 
 Potato. — Scant growth. 
 
 Origin. — Almost always in sour milk, and the chief cause of 
 lactic acid formation. Found at times in combination with 
 B. acidi lactici and other bacteria. Sauer-kraut fermentation 
 is due to streptococcus of lactic acid and yeasts, the latter 
 producing gas. 
 
 Bacterium Bulgaricum. 
 
 Synonym. — Bacterium caucasicus {v. Freudenreich) . 
 
 Origin. — Present in milk. Thought to be a product cf 
 eastern countries, but now recognized as universal. Arises 
 from aHmentary tract. 
 
 Properties. — Produces large amount of acid at higher tem- 
 perature; non-motile. 
 
 Form. — Slender rods, 2 ju to 4 /x long, tending to form 
 threads. 
 
 Staining. — Gram positive. 
 
 Growth. — Best growth at 40° C. Very meager colonies, 
 hardly visible. Curdling homogeneous, changed later into 
 soluble products. Gelatin not liquefied. Used to produce 
 artificial buttermilks. 
 
BACTERIA IN MILK AND FOOD 251 
 
 Potato. — Growth wrinkled and many-folded, gray changing 
 to brown, extending over the entire surface as a thick cover- 
 ing or skin. 
 
 Agar Stroke. — Abundant, grayish, fatty, later on wrinkled 
 skin. 
 
 Gelatin Stab. — On surface, grayish, fatty exudate covered 
 with skin which slowly sinks as the media liquefy. Gelatin 
 liquefied. No gas in sugar bouillon; acid is formed; no 
 indol. Has been found in ropy or gelatinous bread and is 
 considered the cause. 
 
 Bacillus Butyricus (Hiippe). — This bacillus causes bu- 
 tyric-acid fermentation. Supposed to 
 be identical with Bacillus mesentericus. 
 
 Bacillus Amylobacter (Van Tieg- 
 ham) . — Synonyms. — Clostridium butyri- 
 cum (Frasmowsky); Vibrion butyrique of 
 Pasteur; Bacterium saccharobutyricus 
 (Klecki) (Fig. ii8). — Origin. — Found in 
 putrefying plant-infusions, in fossils and 
 conifera of the coal period, in cheese, 
 water, earth. 
 
 Form. — ^Large, thick rods, with 
 
 rounded ends, often found in chains, t^- „ t> .., 
 . , , .' ^ , ^, Fig. 118. — Bacillus 
 
 A large glancmg spore at one end, the amylobacter. 
 
 bacillus becoming spindle shaped in or- 
 der to allow the spore to grow; hence the name, Clostridium. 
 
 Properties. — Very motile; gases arise with butyric smell. 
 In solutions of sugars, lactates, and cellulose-containing 
 plants and vegetables it gives rise to decompositions in 
 which butyric acid is often formed. Casein is also dissolved.' 
 
 A watery solution of iodin will give the starch reaction 
 and color blue some portions of the bacillus; therefore 
 it has been called amylobacter. 
 
 Growth in Glucose Agar. — Rapid at 37°. Small indefinite 
 colonies with gas-bubbles. No growth in gelatin. 
 
 Bacillus Cyanogenes {Bacterium Syncyanum) (Hiippe). 
 — Origin. — Found in blue milk. 
 
252 ESSENTIALS OF BACTERIOLOGY 
 
 Form. — Small narrow rods about three times longer than 
 they are broad; usually found in pairs. The ends are 
 rounded. 
 
 Properties. — They are very motile; do not liquefy gelatin. 
 A bluish-gray pigment is formed outside of the cell, 
 around the medium. The less alkaline the medium, the 
 deeper the color. It does not act upon the milk otherwise 
 than to color it blue. 
 
 Growth. — Grows rapidly, obligate aerobe. 
 
 Colonies on Plate. — Depressed center, surrounded by ring 
 of porcelain-like bluish growth. Dark-brown appearance 
 under microscope. 
 
 Stab-culture. — Grows mainly on surface ; a nail-like growth. 
 The surrounding gelatin becomes colored brown. 
 
 Potato. — The surface covered with a dirty blue scum. 
 
 Attenuation. — ^After prolonged artificial cultivation loses 
 the power to produce pigment. 
 
 Staining. — By ordinary methods. Gram positive. 
 
 Red milk and yellow milk are due to other chromogenic 
 organisms, as, for instance, B. erythrogenes. 
 
 Examination of Milk. — American Standard. — Some bac- 
 teria are found in all milk as ordinarily handled. Strepto- 
 cocci and colon group, when present, always regarded with 
 suspicion. A high-cell leukocyte count, when accompanied 
 by chain bacteria, is an indication of udder disease. There 
 should be several samples taken one week apart and an 
 average made. Bacteria present may be counted in one of 
 three ways. 
 
 Stewart-Slack Method. — Centrifuge i to 2 c.c. of milk; 
 smear sediment on slide, and stain with Jenner or Wright 
 stain and count bacteria in field. 
 
 Prescott-Breed Method. — In a special capillary tube y^ 
 c.c. of milk is sucked up and spread over a square centimeter 
 on a microscopic slide, dried and fixed with methyl-alcohol. 
 Flood with xylol to dissolve fat, stain with methylene-blue 
 or Jenner, and decolorize slightly with alcohol. Focus 15 
 mm. of the specimen and count bacteria and cells present. 
 
BACTERIA IN MILK AND FOOD 253 
 
 Multiply by 5000. This equals the number in y-J-Q- c.c. 
 Count several fields and average the result. 
 
 The Plate Method. — Microscopic examination, while not 
 to be relied upon wholly, gives valuable and quick informa- 
 tion as to the general character of bacteria, their apparent 
 number, the presence or absence of barn-dirt and chain 
 bacteria. The microscopic count differs greatly from plate 
 count, because dead cells as well as living are shown. 
 
 Certified milk should have less than 10,000 bacteria to the 
 cubic centimeter. According to the average taken from a 
 count of four specimens, a rating is given to the milk, and 
 this rating is to be interpreted only as other conditions are 
 considered, such as cleanliness of the cattle and stalls, and 
 chemic composition and method of handling the product. 
 
 Temperature. — Milk kept at 10° F. or lower will not allow 
 ordinary bacteria to develop to any considerable extent; 
 kept at a higher temperature, bacteria develop rapidly. 
 
 Separating or centrifuging permits the bacteria to be con- 
 centrated, and top-milk and cream contain more bacteria per 
 cubic centimeter than whole milk. 
 
 Time, an element. 
 
 Milk freshly drawn, under proper precautions, may con- 
 tain but few bacteria, but in forty-eight to seventy-two hours 
 on ice bacteria will increase enormously. Market milk as 
 ordinarily found in cities may contain millions of bacteria 
 per cubic centimeter. 
 
 Pasteurization. — Milk heated to 60° C. for twenty minutes is 
 called pasteurized. This increases the keeping quality and 
 tends to destroy the vegetative forms of pathogenic bacteria. 
 
 To kill lactic acid, the instantaneous method, higher tem- 
 perature, a few seconds only for pathogenic organisms is 
 required. Pasteurization is beneficial only when there are 
 supervision and inspection of original supply. 
 
 Milk as Source of Contagion. — Harmless Varieties. — 
 Sour milk contains the Bacterium lactis acidi and is not 
 dangerous, and is even considered beneficial, as, for instance, 
 buttermilk. 
 
254 ESSENTIALS OF BACTERIOLOGY 
 
 Neutral Forms. — Many species of air and chromogenic 
 varieties found in milk have no pathogenic properties, 
 neither do they affect the composition of the milk. 
 
 Injurious Organisms. — Human diseases, like typhoid, 
 diphtheria, and scarlet fever, may be conveyed through 
 milk, the infection coming from some one concerned in 
 handling the particular supply. The milk acts as a favorable 
 medium for the pathogenic organisms that accidentally find 
 their way into it. Animals wading in infected water have 
 infected the milk. Utensils washed in polluted water have 
 been found to be the cause in some epidemics of typhoid. 
 Carriers, persons who harbor the diphtheria and typhoid 
 bacteria, but who are not affected with illness, may likewise 
 start epidemics of a kind, especially if working about dairies. 
 Bacteria may enter milk from the animal, as Bacillus tuber- 
 culosis from diseased udder. Infantile diarrheas from the 
 putrefactive Bacillus coli group, streptococcic sore throat 
 from udder disease, are other forms of disease originating in 
 milk. 
 
 Butter and Cheese. — Butter is milk-fat separated by 
 creaming and churning, and as such partakes somewhat of 
 the bacterial nature of the milk from w^hich it is derived. 
 The flavor of butter is due to the character of the acid bac- 
 teria used in souring the milk. By eliminating the gas-form- 
 ing bacteria and by keeping his starting cultures pure the 
 butter-maker can control and develop flavors as easily as 
 the wine-maker. Pure cultures of lactic acid are supplied 
 to butter-makers and used in creameries to inoculate sweet 
 cream and milk. Bacteria coming from unclean utensils, 
 polluted water, or dirty milk undoubtedly affect the flavor 
 and often produce a poor quality of butter. Disease bacteria 
 are not often conveyed through butter, although it is claimed 
 that Bacillus tuberculosis has been found in salted butter. 
 
 Cheese. — The fat and casein salts and sugar-of-milk sepa- 
 rated by curdling from the bulk of soluble portion of milk 
 constitutes cheese. The curdling is accomplished by acid 
 bacteria normally in milk, so-called acid curd cheeses, or by 
 
BACTERIA IN MILK AND FOOD 2$$ 
 
 the use of rennet to form a curd, rennet curd cheese, to which 
 all the important varieties belong. Milk for cheese should 
 be free from Bacillus coli or other deleterious bacteria. The 
 milk for cheese cannot be pasteurized as for butter. 
 
 Testing Milk for Bacillus Coli. — ^A sample of milk is incu- 
 bated at 35° C. for a few hours, noting the curd, whether 
 firm or soft and gassy. 
 
 Wisconsin Test. — Milk curdled by rennet; curd cut and 
 drained and jars kept at 30° C. to 40° C. The curd should 
 have clean acid odor and taste. 
 
 After the curd has been formed, the cheese is allowed to 
 ripen, and this is due to acid-forming bacteria, which permit 
 the pepsin in the rennet to act. Various molds, notably 
 Penicillium and Oidium lactis, are used to give certain 
 foreign cheeses their characteristic flavor. 
 
 Condensed milk has few bacteria in it. The sugar and 
 condensation heat tend to prevent further growth of micro- 
 organisms. 
 
 Concentrated unsweetened milk is a form of pasteurized 
 milk which is reduced in volume one-fourth. It is not always 
 sterile, and bacteria may develop in it if exposed to warmth 
 and air. 
 
 Buttermilk and similar fermented drinks depend on 
 Bacillus lactis acidi and added yeasts. Bacillus bulgaricus 
 gives more acid and allows partial sterilization. 
 
 Foods as a Source of Infection. — Foods eaten after little 
 or no cooking, such as fruits, salads, and the like, and also, 
 oysters, are possible sources of bacterial diseases, and the 
 so-called ptomain poisoning observed after the consumption 
 of ice-cream, sausage, canned meats, etc., is the result of the 
 action of bacteria or their products. 
 
 Oysters and fish from sewage-polluted waters have pro- 
 duced typhoid. Vegetables grown in manured ground or 
 sprinkled with polluted water may be a possible source of 
 disease. The practice of exposing meats and other food to 
 street dust and flies is no doubt responsible for some disease. 
 
 Alcohol and Vinegar Fermentations. — On grapes are to 
 
256 ESSENTIALS OF BACTERIOLOGY 
 
 be found all forms of air bacteria as well as molds and yeasts, 
 some beneficial, some harmful. The acid of grape- juice de- 
 stroys many of the harmful forms, but some persist and 
 must be dealt with by the wine-maker. 
 
 The various yeasts produce alcohol from the sugar of the 
 grape. Vinegar bacteria likewise form a small amount of 
 acetic acid. The wine-maker's success lies in obtaining a 
 clean, unbruised grape, aiding the work of the wine yeasts, and 
 preventing the injurious forms from working. The grapes are 
 crushed and the juice allowed to settle. Pure cultures of 
 tested yeast are used as starters of fermentation. 
 
 Fermentation is regulated by burning sulphur, which in- 
 hibits the growth of molds and harmful bacteria. After 
 fermentation is completed the wine is cleared and freed from 
 all organisms and kept as nearly as possible in a sterile con- 
 dition. 
 
 Beer. — The fermentation is produced by yeasts and with 
 a mixture of grains. Barley or other grains which have been 
 allowed to germinate produce malt. The malt contains the 
 enzjrmes which change starch into sugar. Then, by boiling, 
 the enzyme is destroyed and fermentation by yeasts is per- 
 mitted. The yeasts in modern breweries are pure cultures. 
 
 Wild yeasts or lactic-acid bacteria may contaminate beer. 
 
 Alcohol, brandy, and whisky are likewise the product of 
 yeast fermentation, some sugary substance furnishing the 
 material. 
 
ORGANS AND CAVITIES OF THE HUMAN BODY 257 
 
 CHAPTER XXXIII 
 
 BACTERIOLCGIC EXAMINATION OF THE ORGANS AND 
 CAVITIES OF THE HUMAN BODY 
 
 The body, on account of its constant contact with the sur- 
 rounding air, is necessarily exposed to infection, and we would 
 be likely to find on the skin and in the oral, anal, and nasal 
 cavities the varieties of microorganisms commonly around us. 
 Through the water and food the body is also contaminated, 
 but some organisms by predilection inhabit the mouth, intes- 
 tine, and other cavities, and form there a flora distinctly their 
 own. 
 
 The Skin. — The majority of microorganisms met with on 
 the skin are non-pathogenic, although underneath the nails 
 and in the hair pus-forming microorganisms often occur, 
 producing sometimes serious abscesses on other parts of the 
 body. 
 
 In the sweat-glands and the sebaceous glands various 
 organisms have been found. The Staphylococcus pyogenes 
 seems to be present constantly. 
 
 In foul-smelling perspiration of the feet Rosenbach found 
 microorganisms pathogenic for rabbits. 
 
 Micrococcus cereus albus and flavus, Diplococcus liquefa- 
 ciens albus and flavus. Staphylococcus pyogenes aureus, and 
 Streptococcus pyogenes are found underneath the nails. 
 
 In eczema, Diplococcus albicans tardus, Diplococcus 
 citreus liquefaciens, Diplococcus flavus liquefaciens, and 
 Ascobacillus citreus. 
 
 In colored sweat. Micrococcus haematoides, Bacillus 
 pyocyaneus. 
 
 A diplococcus is found in acute pemphigus. 
 
 The lepra bacillus, the tubercle bacillus in lupus, and the 
 t3rphoid bacillus in the eruption of typhoid fever are a few of 
 the specific germs found on the skin during the disease stage. 
 17 
 
258 ESSENTIALS OF BACTERIOLOGY 
 
 Infection results through some damage of the superficial 
 layers. The injury may be very slight — an expanded hair- 
 foJlicle may suffice to permit entrance of suppurative organ- 
 isms. 
 
 The Conjunctiva. — The micrococcus of trachoma, the 
 Kocli-Weeks bacillus, considered to be the specific cause of 
 acute catarrhal conjunctivitis, or "pink eye," and the Bacillus 
 xerosis, are special germs found on the conjunctiva; the other 
 varieties of air- and water-organisms, and those usually 
 present on the skin, are also found. Loffler's bacillus and 
 the pneumococcus have been found in some forms of con- 
 junctivitis. The Koch-Weeks bacillus is the most contagious. 
 
 A special diplobacillus, known as the bacillus of Morax- 
 Axenfeld, produces a stubborn form of conjunctivitis. 
 
 The gonococcus is found in ophthalmia of the new-born. 
 
 The Mouth. — The mouth is a favorite seat for the devel- 
 opment of bacteria. The alkaline saliva, the particles of 
 food left in the teeth, the decayed teetji themselves, all fur- 
 nish suitable soil for their growth. 
 
 Quite a number of germs have been isolated and their 
 properties partly studied. Many have some connection with 
 the production of caries of the teeth, as Miller has well shown 
 in his careful studies. The Leptothrix buccalis, found in 
 nearly all mouths, is a long chain or filamentous bacillus which 
 stains blue with iodin. It was formerly considered the cause 
 of tartar on the teeth. 
 
 The Spirillum sputigenum, Spirocha?ta dentium, Micro- 
 coccus gingivae pyogenes, Bacillus dentalis viridans, Bacillus 
 pulpae pyogenes, micrococcus of sputum septicemia, and 
 Micrococcus salivarus septicus are a few of the organisms 
 cultivated by Miller and Biondi from the mouth and sup- 
 posed to be separate varieties. Besides these, the pneumo- 
 bacteria, diphtheria bacillus, and tubercle bacillus are often 
 met with, the first two in the mouths of healthy persons. 
 The expired air in quiet respiration is free from bacteria, but 
 in coughing, sneezing, etc., large numbers of organisms are 
 violently ejected and the atmosphere about tubercular 
 
ORGANS AND CAVITIES OF THE HUMAN BODY 259 
 
 patients is often saturated with tubercle bacilli. The bac- 
 teria may enter the system from the pharynx to the tonsils 
 and cervical glands by means of the lymphatics. 
 
 Ear. — In the middle ear of new-born infants no pathogenic 
 organisms have been found, but quite a number of non- 
 pathogenic ones. In affections of the ear the pnemnobacillus 
 and the Staphylococcus pyogenes are most frequent. 
 
 When the streptococcus is present in acute suppurations, 
 there is great danger of mastoiditis. In chronic otitis the 
 gas-forming bacteria, as well as Bacillus pyocyaneus, is often 
 found. 
 
 Nasal Cavity. — The nasal secretion, containing as it does 
 dead cells and being alkaline in reaction, forms a good soil for 
 the growth of germs. 
 
 Diplococcus coryzae. Micrococcus nasalis. Bacillus fcetidus 
 ozaenae, Bacillus striatus albus et flavus, Bacillus capsulatus 
 mucosus, and Vibrio nasalis are some of the organisms de- 
 scribed by various observers. 
 
 Stomach and Intestine. — The secretion of the stomach 
 is in its normal state not a favorable soil for the development 
 of bacteria, yet some germs resist the action of the gastric 
 juice and flourish in it. When the acids of the stomach are 
 diminished in quantity or absent altogether, the conditions 
 for the growth of bacteria are more favorable. The alimen- 
 tary canal of the new^-born infant is sterile, but in a few 
 hours after birth microorganisms begin to appear. 
 
 Some gastric bacteria normally present are Sarcina ventric- 
 uli, Bacterium lactis aerogenes. Bacillus subtilis, Bacillus 
 amylobacter, Bacillus megaterium. 
 
 The intestinal organisms are more numerous, and the 
 mucous lining of the intestines and the secretions there present 
 are favorable to germ-growth. 
 
 Bacillus geniculatus Boas considers a sign of carcinoma of 
 the stomach, and is always present, he claims, when the con- 
 tents contain lactic acid. 
 
 Some investigators consider digestion dependent on micro- 
 bic activity, but experiments with animals have shown that 
 
26o ESSENTIALS OF BACTERIOLOGY 
 
 life and digestion can proceed in a perfectly sterile condition. 
 Food and air sterilized will not develop bacteria in the feces. 
 
 In the feces of the young a great many bacteria have been 
 found that are supposed to stand in close relation with the 
 intestinal disorders common to nurslings. The majority of 
 bacteria usually present in the intestines are non-pathogenic. 
 The following varieties may be met with in the feces: Micro- 
 coccus aerogenes, Bacillus subtilis, Bacillus butyricus, Bacil- 
 lus putrificus coli, Bacillus lactis aerogenes, Bacillus coli 
 commune, Bacillus subtiliformis, and the bacteria of cholera, 
 dysentery, and typhoid, besides many yeast-cells. 
 
 Genito-urinary Passages. — In vaginal secretion Bumm 
 has been able to find a number of organisms, some of which 
 closely resemble the gonococcus; thus, there is the Diplococ- 
 cus subflavus. Micrococcus lacteus faviformis, Diplococcus 
 albicans amplus, and the vaginal bacillus. 
 
 In the urethra of healthy persons bacteria are sometimes 
 found, usually having entered from the air. 
 
 In the normal secretions around the prepuce a bacillus 
 called the smegma bacillus has been discovered. The spiro- 
 chaete of syphilis can be obtained from lesions about the 
 genitalia. 
 
 From urethral pus a number of diplococci other than the 
 gonococci have been isolated. 
 
 From the urine itself a great number of bacteria have been 
 obtained, but mostly derived from the air, finding in the 
 urine a suitable soil. The colon and typhoid bacilli gain 
 entrance into the bladder, possibly by way of the urethra, 
 and produce cystitis. In a larger number of typhoid fever 
 patients the bacilli are found in the urine. 
 
 Microorganisms of the Blood. — Many of the bacteria 
 described in this book are found in the blood of the animal 
 infected; anthrax bacilli are always found in the blood. 
 
 When animals are subcutaneously injected with pneumo- 
 cocci they are found in large quantities in the blood. The 
 diseases of a hemorrhagic nature affecting fowls and swine 
 usually show the presence of bacteria in the vascular system. 
 
GERMICIDES, ANTISEPTICS, AND ANTISEPSIS 261 
 
 Bacteria may be recovered from the blood in all forms of 
 septic infection, such as general sepsis, malignant endocar- 
 ditis, puerperal sepsis, and typhoid fever. Tubercle bacilli 
 are rarely if ever obtained from the blood. 
 
 Staining Blood Specimens. — A drop of blood is spread on 
 a cover-glass and stained with the ordinary dyes; but in 
 order to eliminate the coloring-matter of the red corpuscles 
 and bring the stained bacteria more prominently into view, 
 Gunther recommends that the blood, after drying and fixing, 
 should be rinsed in a dilute solution of acetic acid (i to 5 per 
 cent.). The hemoglobin is thereby extracted, and the cor- 
 puscles appear then only as faint outlines. 
 
 Instead of "fixing" by heat, Canon employs alcohol for 
 five minutes, especially in staining for influenza bacilli, which 
 have been detected in the blood. 
 
 Blood Cultures. — ^As large a quantity of blood as pos- 
 sible — never less than 10 c.c. — is taken from a superficial 
 vein, the median basilic, for example, by means of a sterile 
 antitoxin syringe, a small incision being made through the 
 skin over the vein in order to avoid skin infection. The 
 blood so obtained is immediately transferred to culture-tubes, 
 where the organisms are allowed to develop, and are then 
 studied in- the customary manner. 
 
 CHAPTER XXXIV 
 GERMICIDES, ANTISEPTICS, AND ANTISEPSIS 
 
 Sunlight, pure air, and ordinary soap and water are effec- 
 tive disinfectants. Too often the burning of chemicals and 
 the dipping of hands into antiseptic solutions partake of the 
 nature of religious sacrifice, and the more nauseous the odor, 
 the more effective is the incense supposed to be. Much of 
 the perfunctory fumigation by the boards of health after the 
 
262 ESSENTIALS OF BACTERIOLOGY 
 
 minor contagious diseases, instead of teaching the people a 
 lesson, create a false impression of security, and permit them 
 to neglect the commoner means of ordinary cleanliness 
 because of this assumed virtue of fumigation. The whole 
 subject of fumigation and quarantine regulation needs more 
 careful investigation and study. 
 . A germicide is an agent capable of destroying bacterial life. 
 
 An antiseptic solution or substance is one that can inhibit 
 or prevent the growth of bacteria without necessarily de- 
 stroying them. 
 
 A disinfectant must be germicidal. 
 
 A deodorant may have no germicidal or antiseptic properties. 
 
 Preservative's are substances which prevent fermentation, 
 but they are not always germicides. 
 
 In considering the value of a germicide, the strength in 
 which it acts is the main consideration. Some very weak 
 chemicals will inhibit and destroy the growth of bacteria if 
 used in sufficiently concentrated solutions. Some bacteria 
 will die in an acid medium; others are destroyed by too much 
 alkali. Some bacteria are very readily destroyed in pure 
 cultures, but are resistant to a considerable degree in the 
 body tissues. Again, a germicide may be ideal in laboratory 
 experiments, but wholly impractical at the clinic. 
 
 A I : 300,000 solution of mercuric chlorid (corrosive sub- 
 limate) will prevent the development of anthrax spores, but 
 a I : 1000 solution is needed to destroy them. 
 
 Germicides are tested by action in various dilutions or in 
 gaseous form on threads impregnated with virulent and spore- 
 forming organisms. The length of time is noted that it takes 
 to destroy anthrax bacilli or pyogenic organisms. 
 
 The infected material is subjected to the solution and then 
 inoculated on media and compared with control, or tested for 
 virulence on animals. Spore-forming organisms are very 
 resistant to the most potent agents. 
 
 Heat is perhaps the best general germicide. For all articles 
 that can be subjected to boiling or the direct flame there is 
 no safer agent. 
 
GERMICIDES, ANTISEPTICS, AND ANTISEPSIS 263 
 
 Superheated steam , or steam under pressure, is now in 
 general use in sterilizing surgical dressings and instruments, 
 and requires less time than ordinary steam. 
 
 The salts of metals of high atomic weights come next in order. 
 Bichlorid of mercury and cyanid of mercury are the most 
 powerful of chemical germicides, but in the human body they 
 can be used in dilute solutions only, and in contact with 
 highly albuminous solutions, insoluble and inert albuminates 
 are liable to form, lessening the germicidal value. A i : 200 
 solution combined with an acid like citric will destroy the 
 spores of anthrax in one hour, but much weaker solutions will 
 destroy the anthrax bacilli in the blood, and for all practical 
 purposes a i : 2000 solution is suflScient, destrojdng bacterial 
 life in a few minutes. 
 
 One per cent, solution soda lye, NaOH, kills most bacteria 
 in a few minutes, and, therefore, hot soapsuds is quite effec- 
 tive as a germicide. 
 
 Phenol in 5 per cent, solution will destroy most of the bac- 
 teria in less than five minutes. Tricresol, a combination of 
 cresols, has three times the disinfecting power of phenol. 
 
 Formaldehyd, in gaseous. form or in a liquid spray, is a very 
 efficient germicide, and from the fact that it is not destruc- 
 tive to fabrics or paper has^come into general use as a dis- 
 infectant. In combination with potassium permanganate 
 or in suitable generators it is employed in houses after infec- 
 tious diseases. It has no effect on insects, and where it is 
 necessary to destroy these, other agents, known as insecti- 
 cides, must be used in connection with the gas. The gas 
 should be in a moist state — from 6 to 16 ounces for an ordi- 
 nary room are needed; the room should be made as air-tight as 
 possible, and the gas evolved as speedily as possible. 
 
 In the permanganate method 8 ounces (by weight) of 
 potassium permanganate crystals are placed in a large tin 
 vessel ten times the capacity of the disinfectant used. One 
 pint of formaldehyd solution is quickly poured over the 
 crystals. Formaldehyd gas is thereby generated at once. 
 
264 ESSENTIALS OF BACTERIOLOGY 
 
 This will produce enough gas for disinfection of 1000 cubic 
 feet. 
 
 Solid formaldehyd in the form of candles is useful for small 
 rooms, and some health boards employ it exclusively. 
 
 Sulphur dioxid, or sulphurous acid gas, is a germicide and 
 insecticide, and is much used in disinfecting ships after yellow 
 fever and malaria. It is obtained by burning sulphur in a pan 
 over water, and about 3 pounds to 1000 cubic feet are 
 necessary. 
 
 Copper sulphate, i part to 1,000,000 of water, is effective 
 in destroying algce, and is useful in large reservoirs as a tem- 
 porary disinfectant. 
 
 Alcohol, iodin, chlorin, potassium permanganate, hydrogen 
 dioxid, the salts of silver, lead, and zinc, salicylic acid, boric acid, 
 anilin dyes {methyl-violet and methylene-blue) , naphthalin, and 
 creosols are a few of the substances in use as antiseptics and 
 germicides in surgery. Their power varies with the strength 
 of the solution and all have limitations. 
 
 In surgical operations more dependence is placed today 
 on securing and maintaining a germ-free or aseptic condition 
 than on the attempt to destroy germ life by chemicals. The 
 irritation of antiseptics in some instances prevents the natural 
 body defenses (phagocytes) from acting, and in abdominal 
 operations, where no pus has been encountered, the blood- 
 serum is sufficient or normal salt solution is alone used. 
 
 Sterilization of Hands, etc, — It has been shown by elaborate 
 experiments that the skin, the hair, and clothing harbor many 
 bacteria, some of a pathogenic nature. The surgeon who is 
 anxious to secure good results should carefully attend to his 
 toilet; the use of operating gowns, rubber gloves, operating 
 shoes, face guards is now universal. The toilet of the hands 
 of the surgeon is as important as that of the field of operation, 
 but with the use of rubber gloves the painstaking directions as 
 to the employment of a half-dozen or more cleansing agents 
 and germicides are no longer followed. 
 
 Soap is an efficient germicide, the lye being in most cases 
 powerful enough to prevent the growth of germs. 
 
GERMICIDES, ANTISEPTICS, AND ANTISEPSIS 265 
 
 Filtration. — In the laboratory, and on a larger scale in the 
 management of water-works, filtration is a method of steril- 
 ization, acting as it does by mechanically separating bacteria 
 from a solution. 
 
 General Measures for Disinfection. — For discharges — 
 urine, feces, sputum, vomitus — solution of phenol, 5 per cent., 
 also fresh milk of lime, i part lime to 4 parts water. Lime 
 is of value only when sufficient alkali present. Blankets, woolen 
 clothing, soiled handkerchiefs, linen, boiling in steam, for- 
 maldehyd gas, or hot-air exposure. 
 
 Articles of little value should be burned. Books can be sub- 
 jected to formaldehyd vapor or immersed in gasolene. 
 
 The hands and body w^ashed in strong soapsuds and then 
 in I : 1000 mercuric chlorid solution. 
 
 Tincture of iodin, for the skin and hairy parts, painted 
 over the field of operation, has come into vogue as a very 
 efficient antiseptic. 
 
 Woodwork and floors should be washed with soapsuds 
 and I : 1000 solution of mercuric chlorid, the room itself 
 subjected to formaldehyd vapor. 
 
 Testing the Value of Disinfectants. — Rideal-Walker 
 Standard. — For comparing one disinfectant with another, 
 they are compared with phenol solutions of known strength 
 in their action on a culture of some microorganism (the 
 Bacillus typhosus is now used in most laboratories). A 
 Standard temperature of 20° C. has been adopted by the 
 workers of the United States Hygienic Laboratory, and some 
 changes have been made by them in the Rideal-Walker 
 method, so that it is referred to as the "Hygienic Labor- 
 atory Phenol Coefficient.^' 
 
 The medium is made of beef-extract, according to the 
 American Health Association standard, and must have a 
 reaction of +1.5 in test-tubes containing 10 c.c. each of the 
 medium. 
 
 The organism is a twenty-four-hour-old filtered broth 
 culture of the Bacillus typhosus. Temperature of cultures 
 and dilutions must be brought up to 20° C. 
 
266 
 
 ESSENTIALS OF BACTERIOLOGY 
 
 One- tenth of a cubic centimeter of the culture is 
 added to 5 c.c. of the disinfectant dilution. The phenol 
 control is made of different dilutions, from 5 to 10 strengths 
 being employed. The disinfectant to be tested is likewise 
 diluted, depending on the solubility, etc. An accurately 
 graduated pipet distributes yV ^.c. of the culture to each 
 one of the dilutions, both of the phenol control and the test, 
 and the tubes are then shaken gently three times. At 
 intervals of two and one-half minutes a platinum loopful 
 (the loop 4 mm. in diameter) is transferred from each tube 
 and planted in the tube of broth medium. The inoculated 
 tubes are then placed in an incubator at 37° C. for forty- 
 eight hours, and at the end of this time results are recorded. 
 
 The coefficient is determined and recorded as in the ex- 
 ample here given. 
 
 Example. 
 
 Name of disinfectant to be tested, A. 
 Temperature, 20° C. 
 Culture used. Bacillus typhosus, o.i 
 fectant. 
 
 c.c. to 5 c.c. disin- 
 
 DlLUTION 
 
 Phenol: 
 
 I : 80 . . 
 
 I : 90. . 
 
 I : 100. 
 
 I : no. 
 Disinfectant 
 
 I :350- 
 
 I :375- 
 
 I : 400 . 
 
 I : 500. 
 
 I : 650. 
 
 Time Exposed in Minutes 
 
 + — 
 
 + i + 
 
 + I + 
 
 iy2 
 
 15 
 
 The weakest disinfectant dilution that kills within two and 
 one-half minutes (1-375) is divided by the weakest phenol 
 
GERMICIDES, ANTISEPTICS, AND ANTISEPSIS 267 
 
 dilution (i:8o), thus -^ = 4.69, and the same is done for 
 the strength that kills in fifteen minutes, namely: 
 
 ^- 5.9X 
 
 no 
 
 The average of these, ^^^^-^^^ = 5.30, is called the co- 
 efficient. In other words, disinfectant A has a value of 
 5.30 times that of phenol. A disinfectant with a phenol 
 coefl5cient less than i is of very low germicidal value. 
 
268 
 
 CHIEF CHARACTERISTICS 
 
 CHIEF CHARACTERISTICS 
 PART I.— 
 
 This classification into non-pathogenic and pathogenic is not strictly correct, as 
 
 
 
 special 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product 
 
 ACETI. 
 
 Bacillus. 
 
 Short motile rods in 
 zooglea; aerobic. 
 
 Ferment. 
 
 ACIDI LACTICI. 
 
 Bacillus. 
 
 Short, immotile rods; 
 aerobic. 
 
 
 ACIDI LACTICI. 
 
 Streptococcus. 
 
 Short, immotile, oval 
 cocci. 
 
 .... 
 
 ACTINOBACTER, 
 
 Bacillus. 
 
 Immotile rods with 
 capsule; facul. an- 
 aerob. 
 
 
 Aerogenes. 
 
 Bacillus. 
 
 Identical with B. 
 acid lactici. 
 
 
 Aerophilus. 
 
 Bacillus. 
 
 Slender rods in threads ; 
 immotile; oval 
 spores; aerobic. 
 
 
 Agilis. 
 
 Micrococcus. 
 
 Mobile diplococci 
 with fine flagella. 
 
 Red pigment. 
 
 Alba, 
 
 Beggiatoa. 
 
 Cocci and spirals with 
 sulphur. 
 
 
 Alba. 
 
 Sarcina. 
 
 Small cocci in packets 
 
 White pigment. 
 
 Albicans amplus. 
 
 Micrococcus. 
 
 Large cocci and dip- 
 lococci. 
 
 .... 
 
 Albicans tardissi- 
 
 Micrococcus. 
 
 Diplococci colored by- 
 
 
 MUS. 
 
 
 Gram. 
 
 
 Albicans tardus. 
 
 Micrococcus. 
 
 Diplococci not motile. 
 
 .... 
 
 Allii. 
 
 Bacillus. 
 
 Very small rods. 
 
 Alkaloid pigment. 
 
 Amyliferum. 
 
 Spirillum. 
 
 Rigid spirilla with 
 spores; turns blue 
 with iodin. 
 
 
 Amylobacter. 
 
 Bacillus. 
 
 See Butyriaim, with 
 
 which it is identical. 
 
 Aquatilis. 
 
 Micrococcus. 
 
 Very small cocci in ir- 
 regular groups. 
 
 
 Arachnoidea. 
 
 Beggiatoa. 
 
 Very thick filaments 
 containing sulphur; 
 motile. 
 
 
 Arborescens. 
 
 Bacillus. 
 
 Thin rods, with round- 
 ed ends in threads, 
 andsingly ;immotile. 
 
 Yellow pigment. 
 
 Attenuatum. 
 
 Spirillum. 
 
 Threads with narrow- 
 ed ends. 
 Small cocci in pairs 
 
 
 AURANTIACA. 
 
 Sarcina. 
 
 Orange-yellow pig- 
 
 
 
 and tetrads; strongly 
 
 ment. 
 
 
 
 aerobic. 
 
 
 AURANTIACUS. 
 
 -Bacillus. 
 
 Motile, short thick 
 
 ' Orange-yellow pig- 
 
 
 
 rods, often in long 
 
 ment. 
 
 
 
 threads. 
 
 i 
 
OF THE PRINCIPAL BACTERIA 
 
 269 
 
 OF THE PRINCIPAL BACTERIA. 
 NON-PATHOGENIC BACTERIA. 
 
 many of the non-pathogenic varieties have disease-producing properties under 
 conditions. 
 
 Culture Characters. 
 
 Not liquefy; membran- 
 ous growth. 
 
 Not liquefy; small white 
 points, porcelain-like; 
 slow. 
 
 Growth faster than above 
 appearance same. 
 
 Liquefy rapidly; small 
 yellow-gray colonies. 
 
 Slowly liquefying, form- 
 ing a cone with rose- 
 red color. 
 
 Slow growth in small 
 
 white colonies. 
 Slowly liquefy; gray col- 
 onies; growth fairly 
 
 rapid. 
 Small white points, not 
 
 Hauefying; very slow 
 
 growth. 
 Grows slowly on surface, 
 
 the boundary raised; 
 
 twice as large as above. 
 Bright-green pellicle on 
 
 agar. 
 
 Light-yellow colonies; 
 serrated edges. 
 
 Colonies, radiating fr;ara 
 an oval center like 
 roots; later on colored 
 yellow; slowly liquefy. 
 
 Rapidly liquefy; little 
 orange-yellow colonies, 
 not growing in high 
 temperature. 
 
 Slowly growing; nail cul- 
 tures; shining and 
 orange-yellow; not li- 
 quefy. 
 
 Actions. 
 
 Produces acetic-acid 
 fermentation. 
 
 Lactic-acid fermenta- 
 tion; precipitates 
 casein. 
 
 Alcohol is formed af- 
 ter the lactic-acid 
 fermentation. 
 
 Causes fermentation 
 with gas and alcohol. 
 
 Is colored by Gram' 
 method. 
 
 Decomposes albumin. 
 
 Habitat. 
 
 Air. 
 
 Air; sour milk 
 
 Sour milk. 
 
 Air. 
 
 Old cultures. 
 
 Drinking-water. 
 
 Sulphur springs. 
 Air and water. 
 Vaginal secretion. 
 
 Urethral pus. 
 
 Skin in eczema. 
 
 Green slime of 
 
 onions. 
 Water. 
 
 Old distilled water. 
 Sulphur water. 
 
 London Water- 
 works. 
 
 Stagnant water. 
 Air and water. 
 
 Water. 
 
 Discoverer. 
 
 Kiitzing. 
 Pasteur. 
 
 Grotenfeldt. 
 
 Duclaux. 
 
 Miller. 
 Liborius. 
 
 Ali-Cohen. 
 
 Vauch. 
 
 Zimmerman. 
 
 Bumm. 
 
 Bumm. 
 
 Unna, 
 Tommasoli. 
 
 Griffiths. 
 
 Van Tiegham. 
 
 Bolton. 
 Agardh. 
 
 Frankland. 
 
 Warming. 
 Koch. 
 
 Frankland. 
 
27© 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. , Product. 
 
 AURANTIACUS. 
 
 Micrococcus. 
 
 Oval cocci in pairs and Orange-yellow Dig- 
 
 
 
 singly; immotile. 
 
 ment in water, al- 
 cohol, and ether; 
 insoluble. 
 
 Aurea. 
 
 Sarcina. 
 
 Cocci in packets. 
 
 1 Golden-colored pig- 
 
 
 
 ' ment; soluble in 
 
 
 
 alcohol. 
 
 Aureus. 
 
 Bacillus. 
 
 ; Straight motile rods : Golden-yellow pig- 
 
 
 
 lying parallel. 
 
 ment. 
 
 Balticus. 
 
 Bacillus. 
 
 Short rod. 
 
 Phosphorescence. 
 
 BlENSTOCKII. 
 
 Bacillus. 
 
 See Putrificiis, colt. 
 
 
 BiFIDUS. 
 
 Bacillus. 
 
 Slender diplococcus, 
 pointed ends, non- 
 motile, anaerobic. 
 
 
 BiLLROTHII. 
 
 Micrococcus 
 
 Groups of cocci sur- 
 
 
 
 (ascococcus). 
 
 rounded with cap- 
 sule; zooglea, aero- 
 bic. 
 
 
 Brunneus. 
 
 Bacillus. 
 
 Motile rods. 
 
 Brown pigment. 
 
 Butyric-acid fer- 
 
 Bacillus. 
 
 Large, slender motile 
 
 Diastase. 
 
 mentation. 
 
 
 rods in pairs ;spores; 
 facul. anaerobin. 
 
 
 BuTYRicuM (amy- 
 
 Clostridium. 
 
 Thick motile rods en- 
 
 Amyloid substance. 
 
 lobacter). 
 
 
 1 a r g i n g for the 
 spores; obligate 
 . aerobic. 
 
 
 C^RULEUS. 
 
 Bacillus. 
 
 Rods in long chains. 
 
 Blue pigment, not sol- 
 uble in water, alco- 
 hol, or acid. 
 
 Candicans 
 
 Micrococcus. 
 
 Masses of cocci. 
 
 
 (candidus). 
 
 
 
 
 Carotarum. 
 
 Bacillus. 
 
 Threads of rods that 
 bend in various di- 
 rections; oval spores 
 
 
 
 Catenula. 
 
 Bacillus. 
 
 Motile rods with 
 spores. 
 
 .... 
 
 Caucasicus. 
 
 Bacillus. 
 
 Motile rods, with 
 spores in each end. 
 
 
 
 Cerasinus siccus. 
 
 Micrococcus. 
 
 Very small cocci, 
 singly and in pairs; 
 aerobic. 
 
 Cherry-red pigment. 
 
 Cereus albus. 
 
 Micrococcus. 
 
 Cocci in short chains 
 and bunches.colored 
 by Gram. 
 
 
 Cereus flavus. 
 
 Micrococcus. 
 
 Staphylococcus and 
 streptococcus, and 
 in zooglea, colored 
 by Gram. 
 
 
 
 Chlorinus. 
 
 Bacillus. 
 
 Large rods, motile. 
 
 Green pigment, sol- 
 
 
 
 green-colored, due 
 
 uble in alcohol. 
 
 
 
 to chlorophyll; 
 
 
 
 
 aerobic. 
 
 
OF THE PRINCIPAL BACTERIA 
 Bacteeia. — (Continued.) 
 
 271 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Round orange-yellow col- 
 
 
 Water. 
 
 Cohn. 
 
 onies, mostly on sur- 
 
 
 
 
 face; slow growth; not 
 
 
 
 
 liquefying. 
 
 
 
 
 Liquefy; bright golden 
 
 
 
 Exudate of pneu- 
 
 Mace. 
 
 layer on potato. 
 
 
 monia. 
 
 
 Slow-growing, chrome- 
 
 
 Water and skin of 
 
 Adametz and 
 
 yellow, whetstone in 
 
 
 eczema. 
 
 Unha. 
 
 shape; not liquefy. 
 
 
 
 
 Do not liquefy; require 
 
 
 Baltic Sea. 
 
 Fischer. 
 
 glucose for growth. 
 
 
 
 
 Oval colonies after three 
 
 Feces of infants 
 
 
 Tissier. 
 
 days on glucose agar. 
 
 breast-fed. 
 
 
 
 Creamy layer on surface 
 
 
 Putrid broth. 
 
 Cohn. 
 
 of gelatin. 
 
 
 
 
 
 
 Maize. 
 
 Schroter. 
 
 Liquefy rapidly; gray veil 
 
 Casein precipitates 
 
 Air. 
 
 Hueppe. 
 
 on surface of potato. 
 
 and changed into 
 butyric acid; am- 
 monia set free. 
 
 
 
 N3t cultivated. 
 
 Forms butyric acid in 
 
 Air, earth, and 
 
 Prazmowski 
 
 
 presence of lactic 
 
 water. 
 
 and Van 
 
 
 acid. 
 
 
 Tiegham. 
 
 Liquefy; a deep-blue lay- 
 
 
 
 Water. 
 
 Smith. 
 
 er on potato. 
 
 
 
 
 Not liquefy; nail-shaped 
 
 
 Air around old cul- 
 
 Fliigge. 
 
 in test-tube. 
 
 
 tures. 
 
 
 Rapidly liquefy on sur- 
 
 
 Cooked carrots 
 
 A. Koch. 
 
 face, a network center 
 
 
 and beets. 
 
 
 on potato; round, light 
 
 
 
 
 gray; grow rapidly. 
 
 
 
 
 
 Causes albumin to- 
 
 Old cheese. 
 
 Duclaux. 
 
 
 ferment. 
 
 
 
 
 Ferments milk, pro- 
 
 Kefir; grain. 
 
 Kern. 
 
 
 ducing the kefir 
 
 
 
 
 drink. 
 
 
 
 On potato; rapidly form- 
 
 
 Water. 
 
 List. 
 
 ing cherry-red scum, 
 
 
 
 
 not developed on gela- 
 
 
 
 
 tin. 
 Not liquefy; small, wax- 
 
 
 Pus. 
 
 Passet. 
 
 like drops; thick gray 
 
 
 
 
 layer on potato; 
 
 
 
 
 growth rapid. 
 
 
 
 
 Not liquefy; dark-yellow 
 
 
 Pus. 
 
 Passet. 
 
 colonies; wax-like ap- 
 
 
 
 
 pearance. 
 
 
 
 
 Liquefy; greenish-yellow 
 
 
 Water. 
 
 Engelman. 
 
 colonies. 
 
 
 
 
272 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Chlorinus. 
 
 Micrococcus. 
 
 Cocci in zooglea. 
 
 Green pigment, sol- 
 uble in alcohol and 
 water. 
 
 CiNNABAREUS. 
 
 Micrococcus. 
 
 Large oval cocci in 
 
 Brown-red pigment; 
 
 
 
 pairs ; aerobic. 
 
 foul odor. 
 
 ClTREUS. 
 
 Bacillus (asco- 
 
 Straight and bent 
 
 Citron - yellow pig- 
 
 
 coccus). 
 
 rods in bundles; 
 motile. 
 
 ment. 
 
 ClTREUS. 
 
 Micrococcus. 
 
 Large round cocci in 
 
 Cream-colored pig- 
 
 
 
 chains of eight and 
 
 ment. 
 
 
 
 more. 
 
 
 ClTREUS CONGLOM- 
 
 Micrococcus. 
 
 Diplococci and tet- 
 
 
 ERATUS. 
 
 
 rads; aerobic. 
 
 
 Claviformis. 
 
 Bacillus 
 
 Small rods; spores; 
 
 
 
 (tyrothrix). 
 
 true anaerobin. 
 
 
 Cloac.e. 
 
 See Proteus. 
 
 
 
 CONCENTRICUM. 
 
 Spirillum. 
 
 Thick motile spirals 
 with flagella; 
 aerobic. 
 
 
 
 CORONATUS. 
 
 Micrococcus. 
 
 Cocci singlyandstrep- 
 tococci; aerobic. 
 
 
 CORYZ^. 
 
 Micrococcus. 
 
 Large diplococci with 
 rounded ends, the 
 contact surfaces fiat. 
 
 
 Crepesculum. 
 
 Micrococcus. 
 
 Round and oval cocci, 
 singly and in zo- 
 oglea. 
 
 
 Cyaneus. 
 
 Micrococcus. 
 
 Oval cells. 
 
 Blue pigment. 
 
 Cyanogenus (blue 
 
 Bacillus. 
 
 Motile rods in chains; 
 
 Alkali and a pigment 
 
 milk). 
 
 
 spores; aerobic. 
 
 deepened by acids. 
 
 DiCHOTOMA. 
 
 Cladothrix. 
 
 Various forms — rods, 
 spirals, and cocci, in 
 long threads. 
 
 
 DiFFLUENS. 
 
 Micrococcus. 
 
 Oval cocci; aerobic. 
 
 Fluorescent pigment, 
 soluble in water. 
 
 DiSTORTUS. 
 
 Bacillus 
 
 Motile rods; spores; 
 
 Alkali. 
 
 
 (tyrothrix) . 
 
 aerobic. 
 
 
 Dysodes. 
 
 Bacillus. 
 
 Long and short rods; 
 
 An odor resembling 
 
 
 
 spores. 
 
 peppermint and 
 turpentine. 
 
 Endoparagogicum. 
 
 Spirillum. 
 
 Dry motile spirals, 
 joined in peculiar 
 shapes. 
 
 
 Erythrosporus. 
 
 Bacillus. 
 
 Motile rods and 
 
 Greenish-yellow pig- 
 
 
 
 threads; spores, 
 
 ment. 
 
 
 
 slender. 
 
 
 FiGURANS 
 
 Bacillus. 
 
 Large motile rods; 
 
 
 (mycoides). 
 
 
 spores ;long threads; 
 aerobic. 
 
 
 FiLIFORMIS. 
 
 Bacillus 
 
 Short motile rods; 
 
 
 
 (tyrothrix). 
 
 spores in one end. 
 
 
or THE PRINCIPAL BACTERIA 
 
 273 
 
 Bacteria. — {Continued.) 
 
 Culture Characters. 
 
 Actions. 
 
 Yellow-green layer on 
 gelatin. 
 
 Not liquefy; slow growth; 
 bright-red points. 
 
 Slow growth; after two 
 weeks small yellow 
 points which take va- 
 rious shapes on potato; 
 citron-yellow layer; 
 growth more rapid. 
 
 Dirty, cream-colored col- 
 onies, which are raised 
 and moist. 
 
 Lemon-yellow colonies. 
 
 Not liquefying; concen- 
 trically disposed colon- 
 ies; very slow growth; 
 not growing on potato. 
 
 A halo formed around 
 the colonies. 
 
 White, raised glassy col- 
 onies, at first like pneu- 
 mococci, later culture 
 flattened; not lique- 
 fying. 
 
 Bluish-green colonies. 
 Not liquefying; small 
 
 white colonies. 
 Cultivated in infusion of 
 
 plants. 
 
 Do not liquefy; small 
 granular, yellow col- 
 onies; green fluores- 
 cence. 
 
 Does not liquefy; green 
 fluorescence; white col- 
 onies. 
 
 Liquefying; root-like pro- 
 cesses extending in the 
 gelatin; feather form in 
 test-tube. 
 
 Ferments milk, giving 
 rise to alcohol. 
 
 No pathogenic action. 
 
 Changes milk to deep- 
 blue color. 
 
 Milk made viscid and 
 casein precipitated. 
 
 Causes casein to be 
 precipitated from 
 milk. 
 
 Habitat. 
 
 Boiled eggs. 
 
 Air and water. 
 Skin in eczema. 
 
 Water. 
 
 Dust and blennor- 
 rhagic pus. 
 
 Fermenting albu- 
 min. 
 
 Putrefying blood. 
 
 Air. 
 
 Acute coryzal 
 cretion. 
 
 Putrefying infu- 
 sions. 
 
 Cooked potatoes. 
 Air of certain 
 
 countries. 
 Water. 
 
 Air. 
 
 Air. 
 
 Bread and yeast. 
 
 Trunk of worm- 
 eaten tree. 
 
 Air and putrefying 
 substances. 
 
 Garden-earth. 
 
 Discoverer. 
 
 Cohn. 
 
 Flugge. 
 
 Unna and 
 Tommasoli. 
 
 List. 
 
 Bumm. 
 Duclaux. 
 
 Kitasato. 
 
 Flugge. 
 Hajek. 
 
 Cohn. 
 
 Cohn. 
 Fuchs. 
 
 Cohn. 
 Schroter. 
 
 Duclaux. 
 Zopf. 
 
 Sorokin. 
 
 Cohn. 
 
 FlUgge. 
 
 Duclaux. 
 
 18 
 
274 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 Name. 
 
 GEIfUS. 
 
 FiSCHERI. 
 
 Bacillus. 
 
 FiTZIANUS. 
 
 Bacillus. 
 
 Flava. 
 
 Sarcina. 
 
 Flavus. 
 
 Bacillus. 
 
 Flavus desidens. 
 
 Streptococcus. 
 
 Flavus liquefa- 
 
 CIENS. 
 
 Flavus tardi- 
 
 gradus. 
 Fluorescens f<e- 
 
 TIpUS. 
 
 Fluorescens 
 liquefaciens. 
 
 Fluorescens niva- 
 lis. 
 
 Micrococcus. 
 Micrococcus. 
 Micrococcus. 
 
 Bacillus. 
 Bacillus. 
 
 Fluorescens pu- Bacillus. 
 
 TRIDUS. 
 
 Fcetidum. 
 
 Fcetidus. 
 Fuscescens. 
 
 FULVUS. 
 
 FUSCUS LIMBATUS. 
 
 FUSIFORME. 
 
 GlTNICULATUS. 
 
 GiGANTEUS URE- 
 THRA. 
 
 Grass. See Tim- 
 
 othy. 
 Graveolens. 
 
 H/EMATODES. 
 
 Cladothrix. 
 Clostridium. 
 
 Micrococcus. 
 Sarcina. 
 Micrococcus. 
 Bacillus. 
 
 Bacillus. 
 
 Bacillus 
 
 (tyrothrix). 
 Micrococcus. 
 
 Bacillus. 
 
 Micrococcus. 
 
 Biology. 
 
 Product. 
 
 Short rods in threads; 
 spores as large as 
 the rods. 
 
 Small cocci in pack- 
 ets. 
 
 Small rods; immotile. 
 
 Phosphorescence. 
 
 Pigment. 
 Pigment. 
 
 Cocci and diplococci Yellow-brown pig- 
 in chains; aerobic, j ment. 
 
 Cocci and diplococci Pigment, 
 in zooglea. 
 
 Cocci in short chains, Chrome-yellow pig- 
 
 and diplococci. 
 Small diplococci. 
 
 Short motile rods; 
 
 very thin. 
 Short rods; motile. 
 
 Motile rods; short, 
 with rounded ends. 
 
 Threads twisted in 
 spirals; very irreg- 
 ular. 
 
 Rods of varying 
 length; very motile; 
 a large spore in one 
 end ; anaerobic. 
 
 See Crepesculum, with 
 
 Round cocci. 
 
 Short rods; very mo- 
 tile; facultatively 
 anaerobic. 
 
 Spindle-shaped, with 
 pointed ends. 
 
 Rods variable length; 
 spores. 
 
 Streptococci in thick 
 knots. 
 
 Small rods, nearly as 
 broad as they are 
 long. 
 
 ment. 
 Blue-green pigment: 
 acids turn red. 
 
 Green fluorescent 
 
 pigment. 
 Blue-green pigment. 
 
 Green fluorescent 
 pigment. 
 
 Strong gas-produc- 
 tion; very foul odor. 
 
 which it is identical. 
 Brown pigment. 
 
 A bitter substance. 
 
 Foul gas. 
 
 Cocci in little zooglea. Red pigment. 
 
or THE PRINCIPAL BACTERIA 
 Bacteria. — {Continued.) 
 
 275 
 
 Culture Characters. 
 
 Actions, 
 
 Habitat. 
 
 Discoverer. 
 
 Not liquefying; requires 
 
 
 
 Beyerinck. 
 
 peptone for growth. 
 
 
 
 
 Transparent on surface; 
 
 Produces ethylic alco- 
 
 Unboiled hay-in- 
 
 Zopf. 
 
 dark center in t.ie deei) ; 
 
 hol in meat extract. 
 
 fusion. 
 
 
 not liquefying. 
 
 
 
 
 Liquefying. 
 
 
 Vomited matter. 
 
 de Bary. 
 
 Liquefying; yellow viscid 
 
 
 Drinking-water. 
 
 Mace. 
 
 colonies; foul odor. 
 
 
 
 
 Yellow porcelain-white 
 
 
 Air and old cul- 
 
 Flugge. 
 
 colonies. 
 
 
 tures; water. 
 
 
 Liquefying rapidly; yel- 
 
 
 Air and old cul- 
 
 Flugge. 
 
 low colonies. 
 
 
 tures; water. 
 
 
 Softens gelatin; yellow 
 
 
 Air. 
 
 Flugge. 
 
 beads, isolated. 
 
 
 
 
 Little button-like colon- 
 
 
 Post-nasal space. 
 
 Klamann. 
 
 ies that later on sink 
 
 
 
 
 in, surrounded by vio- 
 
 
 
 
 let-green color; lique- 
 
 
 
 
 fying; growth rapid. 
 
 
 
 
 Liquefying; white, sunk- 
 
 .... 
 
 Water and air; 
 
 Flugge. 
 
 en, iridescent colonies. 
 
 
 conjunctival sac. 
 
 
 Quickly liquefying; 
 
 Colors the glacial wa- 
 
 In snow and ice of 
 
 Schmolck. 
 
 growth rapid; small 
 
 ters green. 
 
 Norway. 
 
 
 white points; later on, 
 
 
 
 
 surrounded by blue- 
 
 
 
 
 green fluorescence. 
 
 
 
 
 Not liquefying; transpar- 
 
 
 All putrefactions. 
 
 Flugge. 
 
 ent at first, then green 
 
 
 
 
 fluorescence and urin- 
 
 
 
 
 ary odor. 
 
 
 
 
 
 
 
 Lacrimal canal. 
 
 Cohn. 
 
 Liquefying; growth rapid; 
 
 
 Old cheese and se- 
 
 Liborius. 
 
 small colonies that soon 
 
 
 rum of mice in- 
 
 
 become filled up with 
 
 
 oculated with 
 
 
 fluid and assume a 
 
 
 garden-earth. 
 
 
 spherical form. 
 
 
 
 
 Conic rusty-red colonies. 
 
 
 Excrement of horse. 
 
 Cohn. 
 
 Small brown colonies, 
 
 
 In foul eggs. 
 
 Scheiben- 
 
 along needle-track little 
 
 
 
 zuber. 
 
 branches; not liquefy. 
 
 
 
 
 
 
 Spongy layer on 
 
 Warming. 
 
 
 
 sea-water. 
 
 
 
 
 Air and milk. 
 
 Duclaux. 
 
 No growth on gelatin; on 
 
 
 Normal urine and 
 
 Lustgarten. 
 
 agar, thin drops; nearly 
 
 
 urethra. 
 
 
 transparent ; very slow 
 
 
 
 
 growth; in bouillon, a 
 
 
 
 
 flaky precipitate. 
 Liquefying; irregular 
 
 
 
 
 
 Skin between toes. 
 
 Bordoni- 
 
 grayish, later green- 
 
 
 
 Uffreduzzi. 
 
 ish, colonies, with very 
 
 
 
 
 foul odor. 
 
 
 
 
 Grows best on white of 
 
 
 Sweat of man. 
 
 Zopf. 
 
 egg at 37° C; red layer. 
 
 
 
 
276 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 / 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Hansenii. 
 
 Bacillus. 
 
 Medium large rods. 
 
 Yellow pigment; in- 
 soluble. 
 
 Hay. See SubtiUs. 
 
 
 
 
 Hoffman's. See 
 
 Pseudodiphtheri 
 
 a. 
 
 
 Hyacinthi. 
 
 Bacillus. 
 
 Short rods in dumb- 
 bell shapes. 
 
 .... 
 
 Hyalina. 
 
 Sarcina. 
 
 Round cocci in groups 
 of 4 to 34. 
 
 
 Ianthinus. 
 
 Bacillus. 
 
 See Bacillus violaceus. 
 
 
 Indicus. 
 
 Bacillus. 
 
 Short, motile rods; no 
 
 Scarlet pigment al- 
 
 
 
 spores; anaerobin 
 facul. 
 Very regular packets 
 
 tered by heat. 
 
 Intestinalis. 
 
 Sarcina. 
 
 
 
 
 of cocci, eight in each. 
 
 
 Jequirity. 
 
 Bacillus. 
 
 Medium-sized rods; 
 
 Ferment called 
 
 
 
 spores. 
 
 abrin. 
 
 KUHNIANA. 
 
 Crenothrix. 
 
 Long threads, break- 
 ing up into cocci. 
 Theyareensheathed. 
 
 
 Lacteus favifor- 
 
 Micrococcus. 
 
 Diplococci; not decol- 
 
 
 MIS. 
 
 
 orized by Gram. 
 
 
 Lactis erythrog- 
 
 Bacillus. 
 
 Short immotile rods; 
 
 Yellow pigment and 
 
 enes. 
 
 
 round ends. 
 
 red pigment. 
 
 Leptomitiformis. 
 
 Beggiatoa 
 
 Filaments medium 
 size. 
 
 
 Leucomel^num. 
 
 Spirillum. 
 
 Two or three spirals; 
 dark granular con- 
 tents; clear spaces 
 between. 
 
 
 LiNEOLA. 
 
 Bacillus. 
 
 Short motile rods in 
 zooglea, with flagel- 
 la. 
 
 Short motile rods; 
 
 
 LlODERMOS. 
 
 Bacillus. 
 
 
 
 
 rounded ends. 
 
 
 LiTORALIS. 
 
 Merismopedia. 
 
 Cocci in groups of 
 fours, containing 
 sulphur. 
 
 
 LiTOREUS. 
 
 Bacillus. 
 
 Oval rods, never in 
 chains or zooglea. 
 
 
 LiVIDUS. 
 
 Bacillus. 
 
 Medium-sized rods; 
 
 Deep blue-black 
 
 
 
 motile. 
 
 pigment. 
 
 LUTEA. 
 
 Sarcina. 
 
 Cocci singly and in 
 
 Pigment citron-yel- 
 
 
 
 fours. 
 
 low. 
 
 LUTEUS. 
 
 Bacillus. 
 
 Short immotile rods. 
 
 Pigment; soluble in 
 
 
 
 with large . oval 
 
 water; acids inten- 
 
 
 
 spores. 
 
 sify. 
 
 LUTEUS. 
 
 Micrococcus. 
 
 Oval cocci. 
 
 Pigment, not acted 
 upon by acid or al- 
 kali. 
 
OF THE PRINCIPAL BACTERIA 
 Bacteria. — (Continued.) 
 
 277 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 On potato, a yellow 
 growth which changes 
 with age. 
 
 
 Yellow skin of 
 nutrient infu- 
 sions. 
 
 Rasmussen. 
 
 
 •••• 
 
 Slime of diseased 
 hyacinth-bulbs. 
 
 Wakker. ' 
 
 
 
 Marshes. 
 
 Kutzing. 
 
 Liquefying; oval colon- 
 ies; scarlet-colored. 
 
 
 Intestine of mon- 
 key. 
 
 Koch. 
 
 
 .... 
 
 Intestine of fowls. 
 
 Zopf. 
 
 Colonies brick - colored 
 from oxid of iron. 
 
 Ferment causes oph- 
 thalmia. 
 
 Infusion of jequir- 
 
 ity bean. 
 Drinking-water of 
 
 wells. 
 
 Sattler. 
 Rabenhorst. 
 
 Not liquefying; white col- 
 onies; grow well on po- 
 
 .... 
 
 Mucus of vagina 
 and uterus. 
 
 Bumm. 
 
 tato. 
 Small, round yellow dots, 
 later on cup-shaped, 
 with rose-colored pe- 
 riphery; liquefying. 
 
 
 In red milk and 
 feces. 
 
 Sulphur waters. 
 
 Grotenfeldt. 
 Tr^visan. 
 
 
 
 Water over rot- 
 ting plants. 
 
 Perty. 
 
 Slimy layer on potatoes. 
 
 
 Stagnant water. 
 
 Mullet. 
 
 Liquefying; transparent, 
 then thick layer on po- 
 tato; like gum. 
 
 
 Air and potatoes. 
 Sea-water. 
 
 Fliigge. 
 
 Oersted and 
 Rabenhorst. 
 
 
 
 Sea-water. 
 
 Warming. 
 
 Ink-spot at first, slowly 
 liquefying; blue- violet 
 colored later on; slow 
 
 
 Berlin Water- 
 works. 
 
 Flugge and 
 Proskauer. 
 
 growth. 
 
 Not liquefying; little ele- 
 vations; citron-yellow 
 center; yellow layer 
 on potato. 
 
 Not liquefying; irregu- 
 lar in form; golden- 
 yellow colored. 
 
 Do not liquefy; small 
 citron-yellow colonies 
 on potato. 
 
 .... 
 
 Air. 
 
 Air. 
 Air. 
 
 Schroter. 
 
 Fliigge. 
 SchrSter. 
 
278 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 Name. 
 
 LUTEUS. 
 
 Maidis. 
 
 Marsh. 
 
 Megaterium. 
 
 Melanosporus. 
 
 Merismopedi- 
 
 OIDES. 
 
 M esentericus fus 
 cus (potato). 
 
 Mesentericus 
 
 VULGATUS (potato) 
 
 Mesenteroides. 
 Miller's. 
 
 MiNUTA. 
 
 Mir.\rii.is. 
 
 Multipediculosus 
 Mycoides. See 
 Nasalis. 
 
 Navicula. 
 
 NiTRIFICANS. 
 
 Nivea. 
 nodosus parvus. 
 
 Genus. 
 
 Micrococcus. 
 
 Bacillus. 
 
 Spirillum. 
 
 Bacillus. 
 
 Bacillus. 
 
 Bacillus. 
 
 Bacillus. 
 Bacillus. 
 
 Leukonostoc. 
 
 Bacillus. 
 Sarcina. 
 Beggiatoa. 
 
 Bacillus. 
 
 Rasmosus. 
 
 Micrococcus. 
 
 Bacillus. 
 Micrococcus. 
 Beggiatoa. 
 Bacillus. 
 
 Biology. 
 
 Diplococci very mo- 
 tile. 
 
 Rods with pointed 
 ends, very motile; 
 seldom in threads; 
 oval spores. 
 
 See Plicatile. 
 
 Large motile rods; 
 
 spores; aerobic. 
 Rods; aerobic. 
 
 Threads of rods which 
 are formed from 
 cocci-like spores; 
 zooglea in packets. 
 
 Small motile rods 
 with spores. 
 
 Thick motile rods in 
 threads; spores. 
 
 Masses of cartilagin- 
 ous zooglea, com- 
 posed of rods and 
 cocci; arthrospores. 
 
 Delicate rods, slightly 
 
 curved; immotile. 
 Cube-shaped packets 
 
 Very wide threads, 
 rounded ends and 
 curled; sulphur 
 granules. 
 
 Long, slender rods. 
 
 Diplococci, motile; 
 also streptococci. 
 
 Spindle-shaped rods. 
 
 Small cocci. 
 
 Very thin filaments. 
 
 Rods formed at an- 
 gles; immotile. 
 
 Product. 
 
 Yellow pigment, turn- 
 ing brown-red. 
 
 Black pigment, not 
 acted upon by acids 
 or alkalis. 
 
 Diastase. 
 
 Amyloid material. 
 Forms saltpeter. 
 
OF THE PRINCIPAL BACTERIA 
 Bacteria. — (Continued.) 
 
 279 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Round, light-yellow col- 
 
 
 Water. 
 
 Adametz. 
 
 onies, growing larger 
 
 
 
 
 in a few days; on pota- 
 
 
 
 
 to a slimy covering 
 
 
 
 
 with moldy odor; 
 
 
 
 
 slowly liquefying. 
 
 
 
 
 Gray points in deep, veil- 
 
 In solutions of sugar 
 
 In maize and in 
 
 Paltauf and 
 
 like on surface; lique- 
 
 an aldehyd is pro- 
 
 pellegra; feces. 
 
 Heider. 
 
 fying; on potato, a 
 
 duced. 
 
 
 
 wrinkled skin of 
 
 
 
 
 brownish color. 
 
 
 
 
 Yellow irregular masses; 
 
 
 Cooked cabbage. 
 
 De Bary. 
 
 thick layer on potato. 
 
 
 
 
 First gray, then black. 
 
 
 Air and potatoes. 
 
 Eidam. 
 
 pellicle. 
 
 
 
 
 
 .... 
 
 Stagnant water. 
 
 Zopf. 
 
 Liquefying; white colo- 
 
 
 Potato. 
 
 Flugge. 
 
 nies, ray-like periphery 
 
 
 
 
 brown layer on potato. 
 
 
 
 
 Yellow colonies, dark cen- 
 
 Coagulates milk and 
 
 Air and old pota- 
 
 Flugge. 
 
 ter, ciliary processes at 
 
 forms diastase out of 
 
 toes. 
 
 
 periphery; brown layer 
 
 starch. 
 
 
 
 on potato, penetrating 
 
 
 
 
 the substance. 
 
 
 
 
 
 Converts molasses in- 
 
 Beet-root juice. 
 
 Cienkowski, 
 
 
 to a gelatinous mass. 
 
 
 
 Liquefies; not growing 
 
 
 Caries of teeth. 
 
 Miller. 
 
 on the surface. 
 
 
 
 
 Grows slowly; reacts to 
 
 
 Sour milk. 
 
 De Bary. 
 
 iodin, turning blue. 
 
 
 
 
 
 
 Sea-water. 
 
 Cohn. 
 
 Insect-shaped colonies. 
 
 
 Potatoes. 
 
 ■ 
 Flugge. 
 
 Grayish points, raised. 
 
 
 Nasal space and 
 
 Hack. 
 
 opaque; rapid growth; 
 
 
 secretion. 
 
 
 not liquefying. 
 
 
 
 
 
 
 
 Potatoes. 
 
 Reinke and 
 Berthold. 
 
 
 
 
 Soil. 
 
 VanTiegham 
 
 White flakes. 
 
 
 
 Sulphur waters. 
 
 Rabenhorst. 
 
 Slow growth at 37° C; 
 
 
 Urethral secretion. 
 
 Lustgarten. 
 
 in agar a white line. 
 
 
 
 
 which in the center 
 
 
 
 
 becomes poroiis. 
 
 
 
 
28o 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Oblongus. 
 
 Micrococcus. 
 
 Motile cocci, singly 
 and in filaments; 
 aerobic. 
 
 .... 
 
 OCHROLEUCUS, 
 
 Micrococcus. 
 
 Cocci in pairs and 
 packets; spores. 
 
 Yellow pigment. 
 
 Paludosa. 
 
 Sarcina. 
 
 Spheric, transparent, 
 colorless cocci. 
 
 
 Pasteurianus. 
 
 Bacillus. 
 
 Differs from Bacillus 
 aceti in that the 
 cells contain an 
 amyloid matter. 
 
 
 Pflugeri. 
 
 Bacillus. 
 
 Short rods in threads. 
 
 Phosphorescence. 
 
 Phosphorescens 
 
 Bacillus. 
 
 Motile; round, short 
 
 Phosphorescence. 
 
 GELIDUS. 
 
 
 rods; aerobic. 
 
 
 Phosphorescens 
 
 Bacillus. 
 
 Large motile rods. 
 
 Phosphorescence. 
 
 INDICUS. 
 
 
 
 
 Phosphorescens, 
 
 Bacillus. 
 
 Motile rods. 
 
 Phosphorescence. 
 
 North Sea. 
 
 
 
 
 Photometricus. 
 
 Bacillus. 
 
 Motile, red-colored 
 
 Sulphur and red pig- 
 
 
 
 rods. 
 
 ment caused by 
 light. 
 
 Plicatile. 
 
 Spirillum. 
 
 Long motile, thin 
 spirals; round ends. 
 
 
 POLYMYXA. 
 
 Clostridium. 
 
 Motile rods in threads 
 
 Amyloid colored 
 
 
 
 with spores. 
 
 blue by iodin. 
 
 PRODIGIOSUS. 
 
 Bacillus. 
 
 Short motile rods; 
 
 Red pigment, sol- 
 
 
 
 aerobic. 
 
 uble in alcohol 
 trimethylamin. 
 
 Proteus mirabilis. 
 
 Bacillus. 
 
 Very motile, short 
 rods; aerobic. 
 
 
 Proteus vulgaris. 
 
 Bacillus. 
 
 Rods sometimes 
 curved as spirillum. 
 
 .... 
 
 Proteus Zenkeri. 
 
 Bacillus. 
 
 Motile rods. 
 
 
 
 PSEUDO-DIPHTHE- 
 
 Bacillus. 
 
 Small rods, similar to 
 
 
 RLE(Hoflfnjan). 
 
 
 the true bacillus; 
 immotile. 
 
 
 PUTRIFICUS COLI. 
 
 Bacillus. 
 
 Slender motile rods; 
 long threads; spores. 
 
 
 Pyogenes tenuis. 
 
 Micrococcus. 
 
 
 
 Radiatus. 
 
 Bacillus. 
 
 Motile rods with 
 rounded ends; an- 
 aerobic oval spores. 
 
 Strong-smelling gas. 
 
or THE PRINCIPAL BACTERIA 
 
 281 
 
 BACTEmA.^iContinued.) 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Grows best in cultures to 
 
 Causes gluconic fer- 
 
 Beer. 
 
 Boutroux. 
 
 which glucose and am- 
 
 mentation. 
 
 
 
 monium tartrate have 
 
 
 
 
 been added. 
 
 
 
 
 Liquefying; slow growth; 
 
 
 Urine. 
 
 Prove. 
 
 thin yellow membrane; 
 
 
 
 
 sulphurous odor. 
 
 
 
 
 .... 
 
 
 Water from sugars 
 
 Schroter. 
 
 
 
 factory. 
 
 
 
 
 
 Heavy beers. 
 
 Hansen. 
 
 Not liquefying; requires 
 
 
 Putrid meat and 
 
 Ludwig. 
 
 glucose; grows well on 
 
 
 fish. 
 
 
 potato. 
 
 
 
 
 Not liquefying; grows 
 
 .... 
 
 Salt fish. 
 
 Forster. 
 
 best with glucose and 
 
 
 
 
 salt. 
 
 
 
 
 Liquefying; grows best 
 
 
 Tropical seas. 
 
 Fischer. 
 
 at 30° C. 
 
 
 
 
 Liquefying; colonies look 
 
 
 Water around 
 
 Fischer. 
 
 as if punched out; 
 
 
 Kiel. 
 
 
 grows best at 15° C. 
 
 
 
 
 Movements depend upon 
 
 .... 
 
 
 Engelman. 
 
 light. 
 
 
 
 
 
 
 Stagnant water. 
 
 Ehrenberg. 
 
 Thick skin on potato. 
 
 Causes fermentation in 
 dextrin solutions. 
 
 
 Prazmowski. 
 
 Little red colonies; lique- 
 
 
 Bread and pota- 
 
 Ehrenberg. 
 
 fying rapidly; espe- 
 
 
 toes. 
 
 
 cially abundant on 
 potatoes. 
 Liquefying slowly; 
 
 
 
 
 
 Putrefaction. 
 
 Hauser. 
 
 opaque center, irregu- 
 
 
 
 
 lar processes. 
 
 
 
 
 Liquefying quickly. 
 
 
 Putrefaction. 
 
 Hauser. 
 
 Not liquefying; thick 
 
 
 Putrefaction. 
 
 Hau.ser. 
 
 white layer on potato. 
 
 
 
 
 Grows at ordinary tem- 
 
 Not virulent. 
 
 In diphtheric 
 
 Wellenhof. 
 
 perature, rapidly form- 
 
 
 membrane and 
 
 (Hoffman.) 
 
 ing on surface a brown- 
 
 
 normal pharynx. 
 
 
 ish growth; pin-head 
 
 
 
 
 colonies raised above 
 
 
 
 
 surface; not liquefying. 
 
 
 
 
 
 Decomposes albumin. 
 
 Human feces. 
 
 Bienstock. 
 
 On agar, a glassy growth. 
 
 
 Closed abscesses. 
 
 Rosenbach. 
 
 Liquefying; growth rap- 
 
 Not pathogenic. 
 
 In serum of white 
 
 Luderitz. 
 
 id ; colonies like molds, 
 
 
 mice inoculated 
 
 
 from center radiating 
 
 
 with earth. 
 
 
 in all directions and 
 
 
 
 
 through the gelatin; 
 
 
 
 
 the air must be ex- 
 
 
 
 
 cluded. 
 
 
 
 
282 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Radiatus. 
 
 Streptococcus. 
 
 Small cocci in chains. 
 
 
 Ramosus liquefa- 
 
 Bacillus. 
 
 Motile rods. 
 
 
 CIENS. 
 
 
 
 
 Reitenbachii. 
 
 Merismopedia. 
 
 Cocci in packets or 
 plates; colorless cell- 
 w a 1 1 containing 
 chlorophyll. 
 
 
 RosACEtrs. 
 
 Micrococcus. 
 
 Large cocci in pairs 
 and tetrads. 
 
 Red pigment. 
 
 Rosea. 
 
 Sarcina. 
 
 Spheric cocci in cubi- 
 cal packets. 
 
 .... 
 
 Rosea perseina. 
 
 Beggiatoa. 
 
 Long rods with cocci- 
 
 Pigment called bac- 
 
 
 
 shaped bodies in 
 
 teriopurpurin. 
 
 
 
 them, containing 
 
 
 
 
 sulphur and a red 
 
 
 
 
 pigment. 
 
 
 ROSEUM. 
 
 Spirillum. 
 
 Very short curved 
 
 Pigment soluble in al- 
 
 
 
 rods; motile and 
 
 cohol. 
 
 
 
 spores. 
 
 
 Ruber. 
 
 Bacillus. 
 
 Motile rods in groups. 
 
 Brick-red pigment. 
 
 Rub RUM. 
 
 Spirillum. 
 
 Motile; short spirilla; 
 aerobic. 
 
 Pale- rose pigment. 
 
 RUFUM. 
 
 Spirillum. 
 
 Long motile spirals. 
 
 Red-rose pigment. 
 
 RUGULA. 
 
 Spirillum 
 
 Motile rods, in long 
 
 
 
 (vibrio) . 
 
 spirals, singly and 
 in chains, with flag- 
 ellaand spores; an- 
 aerobic. 
 
 
 Saprogenes. 
 
 Bacillus. 
 
 Large rods, terminal 
 spores ; facultatively 
 anaerobic. 
 
 
 Scaber. 
 
 Bacillus 
 
 Short motile rods in 
 
 Tyrosin and leucin 
 
 
 (tyrothrix) . 
 
 chains; spores; 
 aerobic. 
 
 are formed. 
 
 Scheurlen's. 
 
 Bacillus. 
 
 Short motile rods; 
 spores. 
 
 
 Septicus. 
 
 Bacillus. 
 
 Non-motile rods in 
 threads and spores; 
 anaerobic. 
 
 .... 
 
 Serpens. 
 
 Spirillum. 
 
 Long, lively threads, 
 with three windings. 
 
 
 SiMILIS. 
 
 Bacillus. 
 
 Immotile rods; trans- 
 parent spores. 
 
 
 Spinosus. 
 
 Bacillus. 
 
 Large motile rods; 
 spores; true anaero- 
 bin. 
 
 
 SUBFLAVUS. 
 
 Micrococcus. 
 
 Diplococci colored by 
 Gram's fluid. 
 
 
 SUBTILIFORMIS. 
 
 Bacillus. 
 
 Immotile rods in 
 
 
 
 
 threads; transparent 
 
 • 
 
 
 
 spores. 
 
 
OF THE PRINCIPAL BACTERIA 
 
 283 
 
 Bacteria. — (Continued.) 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Liquefying; white colon- 
 
 
 Air. 
 
 Flugge. 
 
 ies with greenish tinge; 
 
 
 
 
 funnel-shaped in test- 
 
 
 
 
 tube. 
 
 
 
 
 Liquefying; concentric 
 
 
 Air. 
 
 Flugge. 
 
 colonies; funnel-shaped 
 
 
 
 
 in test-tube. 
 
 
 
 Caspary. 
 
 Not liquefying; small red 
 
 
 Air. 
 
 Flugge. 
 
 knobs, with fecal odor. 
 
 
 
 
 
 
 Marshes. 
 
 Schroter. 
 
 .... 
 
 
 Marshes. 
 
 Zopf. 
 
 Not liquefying; thick 
 
 
 Blennorrhagic pus. 
 
 Mace. 
 
 violet colonies; deep 
 
 
 
 
 red on potato. 
 
 
 
 
 
 
 Boiled ri&e. 
 
 Frank. 
 
 Not liquefying; grows 
 
 
 Dead mice. 
 
 Esmarch. 
 
 slowly; pale-rose col- 
 
 
 
 
 onies. 
 
 
 
 
 
 
 Stagnant water. 
 
 Perty. 
 
 Liquefying rapidly ; round 
 
 Causes cellulose to 
 
 Vegetable infu- 
 
 MiiUer. 
 
 yellow dots with zone; 
 
 ferment. 
 
 sions and tartar 
 
 
 fecal odor. 
 
 
 of teeth. 
 
 
 Grows slowly; foul odor. 
 
 .... 
 
 Putrefaction. 
 
 Rosenbach. 
 Duclaux. 
 
 Growth best at 39° C; 
 
 
 In carcinomatous 
 
 Scheurlen. 
 
 slowly liquefying on 
 
 
 and normal 
 
 
 potato; a yellow 
 
 
 mamma. 
 
 
 wrinkled skin, under- 
 
 
 
 
 neath whicha red color. 
 
 
 
 
 
 
 Putrid blood. 
 
 Klein. 
 
 
 .... 
 
 Stagnant water. 
 
 Miiller. 
 
 Grows rapidly. 
 
 
 Human feces. 
 
 Bienstock. 
 
 Liquefying; spiny periph- 
 
 Albuminous decom- 
 
 Garden-earth. 
 
 Luderitz. 
 
 ery; foul odor due to 
 
 position. 
 
 
 
 methylmercaptan. 
 
 
 
 
 Liquefying; yellow dots. 
 
 .... 
 
 Vaginal secretion 
 and lochial dis- 
 cbarges. 
 
 Bumm. 
 
 Grows best at 37° C. 
 
 
 
 Human feces. 
 
 Bienstock. 
 
284 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 SuBTiLis (hay ba- 
 cillus). 
 
 Bacillus. 
 
 Large motile rods, 
 three times longer 
 than broad, in 
 threads, with flag- 
 ella and spores; 
 aerobic. 
 
 
 Syncyaneus. 
 
 Bacillus. 
 
 Same as Cyanogenus. 
 
 
 Synxanthus (yel- 
 low milk). 
 
 Bacillus. 
 
 Short, thin motile 
 rods. 
 
 Yellow pigment, solu- 
 ble in water; simi- 
 lar to anilin colors. 
 
 Tenue. 
 Tenuis. 
 
 Spirillum. 
 
 Bacillus 
 (tyrothrix). 
 
 Large motile spirals 
 
 with flagella. 
 Motile rods in long 
 
 chains; spores. 
 
 .... 
 
 Termo. 
 
 Bacillus. 
 
 Short motile, cocci- 
 like rods in zooglea. 
 
 
 TUMESCENS. 
 
 Bacillus. 
 
 Shortrodswith spores. 
 
 
 TuRcrous. 
 Ulna. 
 
 Undula. 
 
 URE.E. 
 
 Bacillus 
 (tyrothrix). 
 
 Bacillus. 
 
 Spirillum. 
 Bacillus. 
 
 Short immotile rods 
 
 in long chains; 
 
 spores; aerobic. 
 Very large rods in 
 
 chains and singly; 
 
 not very motile; 
 
 large spores. 
 Long motile spirals, 
 
 with flagella. 
 Short rods; spores; 
 
 aerobic. 
 
 Carbonate of ammo- 
 nium. 
 
 Ferment, propyla- 
 min. 
 
 Urin^. 
 Urocephalus. 
 
 Sarcina. 
 
 Bacillus 
 (tyrothrix). 
 
 Small cocci in fami- 
 lies. 
 
 Cylindric motile rods 
 with spores; anae- 
 robic. 
 
 Cubic packets of 8 
 to 64 cocci. 
 
 Rods motile, often in 
 bundles of four. 
 
 .... 
 
 Ventricula. 
 Ventriculi. 
 
 Sarcina. 
 Bacillus. 
 
 .... 
 
 Versicolor. 
 
 Micrococcus. 
 
 Small cocci. 
 
 .... 
 
 ViOLACEUS. ■ 
 
 Bacillus. 
 
 Motile rods, round 
 end; spores. 
 
 Violet pigment, sol- 
 uble in alcohol. 
 
 Violaceus. 
 
 Bacillus. 
 
 Immotile rods, form- 
 ing large spores. 
 
 Violet pigment, like 
 anilin. 
 
 ViRENS. 
 
 Bacillus. 
 
 Straight rods;-spores; 
 immotile; green 
 tinged. 
 
 Supposed to contain 
 chlorophyll. 
 
OF THE PRINCIPAL BACTERIA 
 Bacteria. — (Continued.) 
 
 285 
 
 Culture Characters. 
 
 Liquefying; gray center, 
 wreath - like border; 
 thick layer on potato. 
 
 In boiled milk a yellow 
 pigment is formed. 
 
 Liquefying; opaque cen- 
 ter, yellow layer next, 
 and the periphery 
 lobed ; funnel-shaped 
 in test-tube. 
 
 On boiled carrots a wrin- 
 kled, gelatinous disk. 
 
 A pellicle formed on sur- 
 face of milk; a heavy 
 precipitate beneath. 
 
 On boiled egg little zoog- 
 lea. 
 
 Resembling a globule of 
 fat; grows well in mu- 
 cous urine. 
 
 Not liquefying. 
 
 Round colonies with dark 
 center; slow growth; 
 not liquefying. 
 
 Not liquefying; irides- 
 cent yellow surface. 
 
 Not liquefying; center 
 deep violet; color re- 
 mains on agar a long 
 time. 
 
 Liquefying; transparent 
 colonies, surrounded 
 by violet zone. 
 
 Actions. 
 
 Precipitates casein; 
 forms a pellicle on 
 milk. 
 
 Splits urea into ara- 
 monii carbonas. 
 
 Peptonizes albumin. 
 
 Habitat. 
 
 Soil and dust, hay, 
 etc. 
 
 Boiled milk and 
 potatoes. 
 
 Stagnant water. 
 
 Fermenting cheese 
 and milk. 
 
 Connected with 
 putrefaction of 
 plants. 
 
 Boiled carrots. 
 
 Fermenting milk 
 and cheese. 
 
 Putrefying water 
 and boiled eggs. 
 
 Discoverer. 
 
 Vegetable 
 
 sions. 
 Stale urine. 
 
 infu- 
 
 Bladder. 
 Fermenting milk 
 
 Contents of stom- 
 ach. 
 
 Stomach of dogs 
 fed on meat. 
 
 Air. 
 Water. 
 
 Boiled potato and 
 water. 
 
 Stagnant water. 
 
 Ehrenberg. 
 
 Ehrenberg. 
 
 Ehrenberg. 
 Duclaux. 
 
 Dujardin. 
 
 Zopf. 
 Duclaux. 
 
 Cohn. 
 
 Mailer. 
 Miquel. 
 
 Welcker. 
 Duclaux. 
 
 Goodsir. 
 Raczynssky. 
 
 Flugge. 
 Zopf. 
 
 Schrotcr. 
 VanTiegham 
 
286 
 
 CHIEF CHARACTERISTICS 
 
 Non-Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 ViRESCENS. 
 
 Bacillus. 
 
 Short motile rods 
 
 Deep-green pigment. 
 
 
 
 with flagella very 
 
 turning yellow- 
 
 
 
 broad. 
 
 brown. 
 
 ViRGULA. 
 
 Bacillus 
 
 Slender im motile 
 
 
 
 (tyrothrix) . 
 
 rods; spores aerobic. 
 
 
 ViRIDIS. 
 
 Bacillus. 
 
 Little immotile rods; 
 oval spore, which is 
 tinged green. 
 
 
 Viscosus. 
 
 Bacillus. 
 
 Motile rods, rounded 
 ends, usually in 
 pairs. 
 
 Green pigment. 
 
 Viscosus. 
 
 Micrococcus. 
 
 Streptococci of glob- 
 
 Gummy substance 
 
 
 
 ular cells. 
 
 called viscosa, and 
 ferment. 
 
 VlTICULOSUS. 
 
 Micrococcus. 
 
 Oval cocci in large 
 groups. 
 
 
 VOLUTANS. 
 
 Spirillum. 
 
 Long spirals with 
 flagella. 
 
 .... 
 
 ZOPFII. 
 
 Bacillus. 
 
 Long motile rods, 
 breaking up into 
 spores like cocci. 
 
 
 PART II.— 
 
 Name. 
 
 Aerogenes Capsu- 
 
 LATUS. 
 
 Alkaligenes. 
 Alvei. 
 
 Amylovorus. 
 
 Anthracis Symp- 
 tomatici. 
 
 Anthracis. 
 
 Articulorum 
 (diphtheriticus). 
 
 Genus. 
 
 Bacillus. 
 
 Bacillus. 
 Bacillus. 
 
 Micrococcus. 
 Bacillus. 
 
 Bacillus. 
 
 Micrococcus. 
 
 Biology. 
 
 Usuallyfound in pairs, 
 resembling diplo- 
 cocci, capsulated; 
 obligate anaerobe. 
 
 Rods like colon and 
 typhoid, motile. 
 
 Rods with large 
 spores. 
 
 Oval cells, never in 
 chains. 
 
 Large slender rods 
 with swellings at 
 spore ; anaerobic. 
 
 Straight rods, slightly 
 concave ends; im- 
 motile ; aerobic; 
 spores. 
 
 Oval cocci in long 
 chains, identical 
 with pyogenes. 
 
 Product. 
 
 Gas with character- 
 istic odor. 
 
 Produces alkali in 
 mannite and milk. 
 
 Forms butyric acid. 
 Rancid odor. 
 
 Toxalbumin. 
 
OF THE PRINCIPAL BACTERIA 
 Bacteria. — {Concluded.) 
 
 287 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Deep round colonies, the 
 
 
 Green sputum. 
 
 Frick. 
 
 vicinity colored green; 
 
 
 
 
 grows on surface; slow 
 
 
 
 
 growth; not liquefying. 
 
 
 
 
 
 
 Milk. 
 
 Duclaux. 
 
 .... 
 
 
 Water. 
 
 VanTiegham. 
 
 Rapid growth, liquefying ; 
 
 
 Water and earth. 
 
 Frankland. 
 
 small hair-like pro- 
 
 
 
 
 cesses from colonies; 
 
 
 
 
 later on, viscid and in 
 
 
 
 
 threads, with green 
 
 
 
 
 fluorescence. 
 
 
 
 
 
 Mucoid fermentation 
 
 Beer and wine. 
 
 Pasteur. 
 
 
 in wine and beer. 
 
 
 
 Not liquefying; a fine 
 
 
 Air. 
 
 Fliigge. 
 
 network in the colony; 
 
 
 
 
 mucoidlayer on potato. 
 
 
 
 
 
 
 Marshes. 
 
 Ehrenberg. 
 
 Not liquefying; forms 
 
 
 Intestinal c n- 
 
 Kurth. 
 
 thick coils like braided 
 
 
 tents of fowls. 
 
 
 hair. 
 
 
 
 
 PATHOGENIC BACTERIA. 
 
 Culture Characters 
 
 Acid reaction in litmus 
 milk; coagulates casein 
 with cavity-formation 
 due to gas. 
 
 Colonies like typhoid. 
 
 Liquefying; growths ra- 
 diating from center 
 downward; on potato 
 a dry yellow layer. 
 
 Liquefy gelatin; grow 
 only in atmosphere of 
 hydrogen. 
 
 Liquefying; granular col- 
 onies with irregular 
 border; on potato a 
 dry, creamy layer; in 
 test-tube a thorny, 
 prickly track. 
 
 Grows well on gelatin; 
 pale-gray colonies; not 
 liquefying; slow 
 growth on potato. 
 
 Actions. 
 
 Causes fermentation; 
 can produce gas 
 from proteid alone. 
 
 Feces and water. 
 
 Produces a disease in 
 bees called "foul 
 brood." 
 
 "Fire-blight" in pear 
 
 trees. 
 Causes quarter evil in 
 
 animals. 
 
 Causes splenic fever in 
 animals; malignant 
 pustule in man. 
 
 Fatal in mice and rab- 
 bits. 
 
 Habitat. 
 
 Discoverer. 
 
 Intestinal con- | Welch. 
 
 tents; earth; 
 
 water; raw 
 foods. 
 
 Larvae of bees. 
 
 Blood and tissues. 
 
 Petruschky. 
 
 Cheshire and 
 Cheyne. 
 
 Burrill. 
 Bollinger- 
 
 Found in tissues Rayer and 
 and excreta of i Davaine. 
 diseased animals. 
 
 Mucous membrane 
 of diphtheria. 
 
 Loffler and 
 Cohn. 
 
288 
 
 CHIEF CHARACTERISTICS 
 
 Pathogenic 
 
 Name. 
 
 AVISEPTICUS. 
 BOIVtBYCIS. 
 
 See 
 
 Bordet-Gengou, 
 botulinus, 
 
 BoviSEPTicus. See 
 Bubonic Plague 
 
 (Pestis). 
 
 BUCCALIS. 
 
 Catarrh ALis. 
 
 Cattle Plague 
 
 (Texas fever). 
 Cavicida. 
 
 Chauv^i. See 
 
 Cholera asiatice, 
 
 CHOLERiE GALLI- 
 
 NARUM (chicken 
 cholera) . 
 
 Cholera nostras 
 (Finckler). 
 
 COLI COMMUNIS. 
 
 Crassus sputig- 
 enus. 
 
 Decalvans. 
 
 Genus. 
 
 Biology. 
 
 Hemorrhagic Se 
 Micrococcus. 
 
 See Whooping- 
 Bacillus. 
 
 Hemorrhagic Se 
 Bacillus. 
 
 Leptothrix. 
 
 Micrococcus. 
 
 Bacillus. 
 
 Symptomatic 
 Spirillum. 
 
 Bacillus. 
 
 Spirillum. 
 
 Bacillus. 
 
 Bacillus. 
 
 Micrococcus. 
 
 pticemia. 
 Oval cocci in chains 
 
 and zooglea; motile. 
 cough. 
 Large rounded ends; 
 
 motile; flagellated; 
 
 anaerobic. 
 pticemia. 
 Short thick rods with 
 
 indistinct capsule. 
 
 Long threads in thick 
 bundles, containing 
 masses of cocci and 
 spirals. 
 
 Diplococci at times 
 resembling gono- 
 coccus. 
 
 See Hemorrhagic Sep 
 
 Little rods twice as 
 long as broad. 
 
 Anthrax (Rauschbra 
 Motile, spiral-shaped 
 rods, often in chains; 
 very short fiagella 
 on ends, and strictly 
 aerobic; spores have 
 not been found. 
 
 Immotile, cocci-like 
 rods ; without spores ; 
 strictly aerobic. 
 
 Motile.comma-shaped 
 rods; strictly aero- 
 bic. 
 
 Short motile rods, 
 slightly curved, 
 without spores; fac- 
 ultatively anaerobic. 
 
 Short, thick rods with 
 rounded ends. 
 
 Spheric cells in great 
 numbers. 
 
 Product. 
 
 Butyric acid; and 
 powerful toxin. 
 
 ticemia and Swine 
 
 Propionic acid 
 through decomposi- 
 tion of sugar, 
 nd^. 
 
 Ptomain-like mus- 
 carin and toxalbu- 
 min, soluble in 
 water. 
 
 Toxalbumin. 
 
OF THE PRINCIPAL BACTERIA 
 
 Bacteria. — {Continued.) 
 
 289 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 
 Causes "fiacherie" in 
 
 Intestines of silk- 
 
 B6champ. 
 
 
 silkworms. 
 
 worms. 
 
 
 Gelatin colonies appear 
 
 Sausage and meat 
 
 Intestine of pig. 
 
 Van Ermen- 
 
 as small semi-trans- 
 
 poisoning. 
 
 
 gem. 
 
 parent spheres. 
 
 
 
 
 Does not liquefy gelatin; 
 
 Causes bubonic plague 
 
 Tissues. body 
 
 Yersin and 
 
 white, point-like col- 
 
 
 fluids, and secre- 
 
 Kitasato. 
 
 onies turning gray and 
 
 
 tions of plague 
 
 
 then brown. 
 
 
 ' patients. 
 
 
 
 Causes dental caries. 
 
 Teeth slime. 
 
 Robin. 
 
 At 37° on agar, round. 
 
 Not pathogenic. 
 
 Mucous secretions 
 
 R. Pfeiffer. 
 
 gray colonies, serrated 
 
 
 healthy persons. 
 
 
 edges. 
 
 
 
 
 Plague. 
 
 
 
 
 Not liquefying; irregular 
 
 Kills guinea-pigs. 
 
 Human feces. 
 
 Brieger. 
 
 scale-like colonies, mak- 
 
 
 
 
 ing the gelatin viscid. 
 
 
 
 
 Liquefying slowly, small 
 
 Causes cholera Asia- 
 
 Feces of cholera 
 
 Koch. 
 
 depressed scars giving 
 
 tica in man and a 
 
 patients. 
 
 
 a frosted appearance. 
 
 similar trouble in 
 
 
 
 or like ground glass; 
 
 animals. 
 
 
 
 on potato, aithin brown 
 
 
 
 
 layer; in test-tube, a 
 
 
 
 
 funnel-shaped lique- 
 
 
 
 
 faction, with a bubble 
 
 
 
 
 of air in the top, the 
 
 
 
 
 funnel taking six or 
 
 
 
 
 seven days to form 
 
 
 
 
 well. 
 
 
 
 
 Not liquefying; small iso- 
 
 Causes chicken chol- 
 
 Blood and feces of 
 
 Pasteur. 
 
 lated white disks; in 
 
 era in fowls; not 
 
 diseased fowls. 
 
 
 test-tube, a granular 
 
 acting on man. 
 
 
 
 track: very faint. 
 
 
 
 
 Liquefying rapidly; col- 
 
 Harmless in man; fatal 
 
 Feces of cholera 
 
 Finckler and 
 
 onies yellow-brown 
 
 to guinea-pigs. 
 
 nostras and ca- 
 
 Prior. 
 
 thick masses; in test- 
 
 
 ries of teeth. 
 
 
 tube, funnel formed in 
 
 
 
 
 twenty-four hours. 
 
 
 
 
 dissolving all gelatin 
 
 
 
 
 in two days; profuse 
 
 
 
 
 gray mass on potato. 
 
 
 
 
 Not liquefying; dark cen- 
 
 Fatal to guinea-pigs 
 
 Feces of nursing 
 
 Escherich. 
 
 ter, undulated per- 
 
 and rabbits; causes 
 
 infants; water; 
 
 
 iphery; green-colored 
 
 diarrhea in man; 
 
 choleraic stools. 
 
 
 layer on potato; milky 
 
 ferments sugar. 
 
 
 
 layer on surface of 
 
 
 
 
 test-tube. 
 
 
 
 
 Not liquefN-ing;, oval. 
 
 Mice and rabbits die 
 
 Sputum. 
 
 Kreibohm. 
 
 grayish, slimy colonies; 
 
 in forty-eight hours 
 
 
 
 nail-shaped growth in 
 
 with gastro-enteritis. 
 
 
 
 test-tube. 
 
 
 
 
 .... 
 
 Causes alopecia area- 
 ta. 
 
 In roots of hair. 
 
 Thin. 
 
 19 
 
290 
 
 CHIEF CHARACTERISTICS 
 
 Pathogenic 
 
 Name, 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Dentalis viri- 
 dans. 
 
 Bacillus. 
 
 Slightly curved rods, 
 round ends. 
 
 Gray pigment. 
 
 
 Diarrhea of In- 
 
 Bacillus. 
 
 Motile, medium-sized 
 
 Toxalbumin. 
 
 
 fants. 
 
 
 rods; spores; aero- 
 bic. 
 
 
 
 Diarrhea of 
 
 Meat-poisoning 
 (Enterilidis sporo- 
 
 genes). 
 Diphtheria. 
 
 Diphtheria of 
 
 Calves (Vitu- 
 
 lorum). 
 Diphtheria in 
 
 Pigeons (Colum- 
 
 barum). 
 Diplobacillus of 
 
 Conjunctivitis. 
 
 Bacillus. 
 
 Bacillus. 
 
 Bacillus. 
 Bacillus. 
 Bacillus. 
 
 Rods in groups of two 
 and singly; round 
 ends; spores. 
 
 Immotile, middle- 
 sized rods, rounded 
 ends; facultative 
 anaerobic. 
 
 Long rods in threads. 
 
 Short rods in groups. 
 
 Non-motile; usually 
 occurs in pairs. 
 
 Toxalbumin. 
 
 
 Duck Cholera. 
 
 Bacillus. 
 
 Similar to chicken 
 cholera bacillus; 
 immotile. 
 
 .... 
 
 
 Dysenteric. 
 
 Dysentery (epi- 
 demic). 
 
 Bacillus. 
 Bacillus. 
 
 Resembles typhoid 
 
 bacillus. 
 Short motile rods; 
 
 very thin. 
 
 First slightly 
 then alkaline. 
 
 acid, 
 
 Enteritidis. 
 
 Bacillus. 
 
 Resembles typhoid 
 bacillus. 
 
 .... 
 
 
 Enteritidis sporo- 
 genes. See Diar 
 
 Erysipelas of 
 SwiNE(Rothlauf; 
 rouget du pore). 
 
 rhea of Meat Poi 
 Bacillus. 
 
 soning. 
 
 Small, slender motile 
 rods; facultatively 
 anaerobic. 
 
 Two vaccines, 
 give immunity 
 
 which 
 
 FCETIDUS OZiENA. 
 
 Bacillus. 
 
 Short rods, very mo- 
 tile; in pairs and 
 chains. 
 
 Foul gas. 
 
 
 Frog Plague. 
 Gangrene. 
 
 Bacillus. 
 Micrococcus. 
 
 See Swine Plague. 
 Oval cocci in zooglea. 
 
 
 
 Gigantea. 
 
 Leptothrix. 
 
 Long rods, cocci and 
 short rods in one; 
 thread also spiral. 
 
 
 
OF THE PRINCIPAL BACTERIA 
 
 291 
 
 Bacteria. — (Continued.) 
 
 Culture Characters, 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Not liquefyini:; round, 
 
 Septic processes and 
 
 In caries of teeth. 
 
 Miller. 
 
 sharply outlined col- 
 
 death in mice and 
 
 
 
 onies, with bluish gray 
 
 pigs. 
 
 
 
 opalescence. 
 
 
 
 
 Not liquefying; green 
 
 Causes green diarrhea 
 
 Feces of infants 
 
 Lesage. 
 
 colonies with foul odor. 
 
 in animals when in- 
 
 suffering from 
 
 
 ~ 
 
 travenously injected, 
 and is the cause of 
 green diarrhea in in- 
 fants. 
 
 green diarrhea. 
 
 
 .... 
 
 Causes death in ani- 
 
 Blood and juices 
 
 Klein. 
 
 
 mals, with symptoms 
 
 of choleraic diar- 
 
 
 
 of septicemia. 
 
 rhea. 
 
 
 Not liquefying; little yel- 
 
 Gives rise to diphthe- 
 
 Diphtheric exu- 
 
 Loffler 
 
 lowish colonies; a mem- 
 
 ria in man and ani- 
 
 date. 
 
 (Klebs). 
 
 branous layer on po- 
 
 mals. 
 
 
 
 tato. 
 
 
 
 
 
 When inoculated in 
 
 Diphtheric mem- 
 
 Loffler. 
 
 
 mice causes death. 
 
 brane of calf. 
 
 
 Whitish patches. 
 
 Necrosis in pigeons 
 
 Diphtheric mem- 
 
 Loffler. 
 
 
 and other animals. 
 
 brane in pigeons. 
 
 
 Addition of blood-serum 
 
 Found in subacute 
 
 Conjunctival se- 
 
 Morax. 
 
 to media necessary; 
 
 conjunctivitis. 
 
 cretion. 
 
 
 liquefying. 
 
 
 
 
 Small round yellow col- 
 
 Fatal for ducks, but 
 
 Blood of diseased 
 
 Cornil and 
 
 onies like wax-drops; 
 
 not for chickens or 
 
 ducks. 
 
 Toupet. 
 
 not liquefying. 
 
 pigeons; less active 
 than chicken chol- 
 era; causes diarrhea 
 and exhaustion. 
 
 
 
 Resembles typhoid bacil- 
 
 Produces one variety 
 
 In dysenteric 
 
 Shiga. 
 
 lus in many respects. 
 
 of dysentery. 
 
 stools. 
 
 
 Not liquefying; concen- 
 
 The cause of epidemic 
 
 In feces and mes- 
 
 Chantemesse 
 
 trically arranged colon- 
 
 dysentery in man; 
 
 enteric glands. 
 
 and Widal. 
 
 ies; dry yellow mem- 
 
 enteritis in guinea- 
 
 
 
 brane on potato. 
 
 pigs. 
 
 
 
 Resembles typhoid ex- 
 
 Produces enteritis in 
 
 Intestinal con- 
 
 Gartner. 
 
 cept that it ferments 
 
 man and animals. 
 
 tents; its toxin 
 
 
 dextrose. 
 
 
 in meat of dis- 
 eased animals. 
 
 
 Very delicate silver-gray 
 
 Causes erysipelas in 
 
 Blood and organs 
 
 Loflfler. 
 
 clouds on the gelatin, 
 
 swine and other ani- 
 
 of diseased ani- 
 
 
 like bone-cells; not liq- 
 
 mals; the German 
 
 mals. 
 
 
 uefying; in test-tube a 
 
 "Rotlauf," French 
 
 
 
 very faint clouding. 
 
 "rouget du pore." 
 
 
 
 Small greenish colonies 
 
 Mice are killed by in- 
 
 Secretion of per- 
 
 Hajek. 
 
 which soon become 
 
 jection; rabbits af- 
 
 sons suflFering 
 
 
 liquefied and indistin- 
 
 fected with progres- 
 
 from ozena. 
 
 
 guishable; a foul odor 
 
 sive gangrene. 
 
 
 
 produced. 
 
 
 
 
 Grayish colonies with 
 foul odor. 
 
 
 
 Gangrenous tissue. 
 
 Eberth. 
 
 Causes caries of teeth. 
 
 Diseased teeth of 
 
 Miller. 
 
 
 
 animals. 
 
 
292 
 
 CHIEF CHARACTERISTICS 
 
 Pathogenic 
 
 Name, 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 GiNGIV/E P Y G- 
 
 Bacillus. 
 
 Short thick rods with 
 
 
 ENES. 
 
 
 rounded ends. 
 
 
 Glanders (Rotz, 
 
 Bacillus. 
 
 Slender, immotile 
 
 
 Mallei). 
 
 
 rods; usually singly; 
 spores; facultative- 
 ly anaerobic. 
 
 
 'G0NORRHCE.E 
 
 Micrococcus. 
 
 Diplococci kidney- 
 
 
 (Gonococcus). 
 
 
 shaped; motile; do 
 not color with Gram. 
 
 
 Grouse Disease. 
 
 Bacillus. 
 
 Small rods and oval 
 cocci in chains; im- 
 motile. 
 
 .... 
 
 H^MATOCOCCUS 
 
 Diplococcus. 
 
 Cocci seldom in 
 
 
 BOVIS. 
 
 
 chains; surrounded 
 by a pale zone 
 
 
 HEMOPHILIA NEO- 
 
 Micrococcus. 
 
 
 
 NATORUM. 
 
 
 
 
 Hemorrhagic 
 
 Bacillus. 
 
 Short rods, twice as 
 
 .... 
 
 Septicemia (In- 
 
 
 lon<? as broad; im- 
 
 
 fectious Pleuro- 
 
 
 motile. 
 
 
 pneumonia, Wild 
 
 
 
 
 Plague, German 
 
 
 
 
 Swine Plague, 
 
 
 
 
 Cattle Plague, 
 
 
 
 
 Steer Plague, 
 
 
 
 
 Rabbit Septice- 
 
 
 
 
 mia). 
 
 
 
 
 Hog Cholera 
 
 Bacillus. 
 
 Very motile oval rods, 
 
 Peptonizes milk with. 
 
 (Swedish swine 
 
 
 similar to hemor- 
 
 out coagulation. 
 
 plague). 
 
 
 rhagic septicemia. 
 
 
 Icteroides. 
 
 Bacterium. 
 
 Once supposed to be 
 the cause of yellow 
 fever. Identicalwth 
 Sanarelli. 
 
 
 Influenza. 
 
 Bacillus. 
 
 Very minute rods or 
 in clumps. 
 
 
 Insectorum. 
 
 Micrococcus. 
 
 Oval cells in chains 
 and zooglea; strep- 
 tococci. 
 
 
 Intracellularis 
 
 Diplococcus. 
 
 Resembles gonococ- 
 
 
 Meningitidis. 
 
 
 cus in morphology 
 and arrangement in 
 interior of leuko- 
 cytes. 
 
 
 Koch-Weeks. 
 
 Bacillus. 
 
 Resembles influenza 
 bacillus. 
 
 
 Lactis aerogenes. 
 
 Bacillus. 
 
 Short, thick immotile 
 rods. 
 
 
OF THE PRIJJCIPAL BACTERIA 
 
 293 
 
 Bacteria. — {Contin ued . ) 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Growth rapid; liquefying; 
 
 Fatal to mice, with 
 
 Suppurating pulp 
 
 Miller. 
 
 round colonies, visible 
 
 septic processes. 
 
 of tooth. 
 
 
 to naked eye in twenty- 
 
 
 
 
 four hours. 
 
 
 
 
 Light yellow, like honey. 
 
 Glanders is caused by 
 
 In epithelium and 
 
 Lofiier. 
 
 colonies, turning red- 
 
 the bacillus in man 
 
 ulcerated glands. 
 
 
 brown, in a few days. 
 
 and animals. 
 
 
 
 Grow on blood-serum. 
 
 Gonorrhea in man. 
 
 Gonorrheal pus; 
 in pus-cells and 
 epithelium. 
 
 Neisser. 
 
 Not liquefying; small 
 
 Fatal for mice and 
 
 In blood and or- 
 
 Klein. 
 
 scales which turn gray 
 
 guinea-pigs. 
 
 gans of diseased 
 
 
 in a few days, the edges 
 
 
 grouse. 
 
 
 serrated. 
 
 
 
 
 Best at 38° C; not lique- 
 
 Fatal for rabbits and 
 
 Blood and organs 
 
 Babes. 
 
 fying; small white 
 
 rats; hyperemia of 
 
 of animals dis- 
 
 
 points; sparse growth 
 
 lungs and spleen; 
 
 eased with hemo- 
 
 
 on potato; transparent. 
 
 blood - exudate in 
 peritoneal cavity. 
 
 globinuria. 
 
 
 .... 
 
 Supposed to be the 
 
 Found in this dis- 
 
 Klebs. 
 
 
 cause of the disease. 
 
 ease. 
 
 
 White isolated pinhead 
 
 A disease having dif- 
 
 Blood and serum 
 
 Huppe. 
 
 points, not growing on 
 
 ferent names in dif- 
 
 of diseased ani- 
 
 
 potato; best at 37° C. 
 
 ferent animals.char- 
 
 mals. 
 
 
 not liquefying. 
 
 acterized by edema, 
 hemorrhage, and 
 septicemia. 
 
 
 
 Very good growth on gel- 
 
 In experiment, ani- 
 
 Not spread through 
 
 Salmon and 
 
 atin and potatoes; a 
 
 mal's death in four 
 
 tissue, butin cap- 
 
 Selander. 
 
 yellow-brown color. 
 
 to eight days; bac- 
 
 illaries of dis- 
 
 
 
 teria in little emboli 
 
 eased swine. 
 
 
 
 in capillaries. 
 
 
 
 Grow best on blood-agar; 
 
 Produces epidemic in- 
 
 Secretions of res- 
 
 Pfeiffer. 
 
 colonies very small. 
 
 fluenza. 
 
 piratory tract. 
 
 Kitasato, 
 
 almost transparent. 
 
 
 
 Canon. 
 
 
 A contagious disease 
 
 Stomach of 
 
 Burrill. 
 
 
 in the chinch-bug. 
 
 chinch-bug. 
 
 
 Transparent colonies, 
 
 Causes epidemic cere- 
 
 In cerebrospinal 
 
 Weichsel- 
 
 forming thin layer on 
 
 brospinal meningi- 
 
 fluid and nasal 
 
 baum. 
 
 Loffler's blood-serum 
 
 tis. 
 
 secretions. 
 
 
 and glycerin agar. 
 
 
 
 
 Rarely grows, except on 
 
 Most common cause of 
 
 Conjunctival se- 
 
 Koch and 
 
 serum agar. 
 
 acute contagious 
 conjunctivitis. 
 
 cretion. 
 
 Weeks. 
 
 Small, porcelain-like 
 
 Fatal to guinea-pigs 
 
 Feces of nursing 
 
 Escherich. 
 
 disks with depressed 
 
 and rabbits; coagu- 
 
 infants and of 
 
 
 center; funnel-shaped 
 
 lates milk; decom- 
 
 cholerine. 
 
 
 In test-tube with gas. 
 
 poses sugary solu- 
 tions. 
 
 
 
294 
 
 CHIEF CHARACTERISTICS 
 
 Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Lepr^. 
 
 Bacillus. 
 
 1 Slender, immotile 
 rods with pointed 
 ends. 
 
 
 LiQUEFACIENS CON- 
 JUNCTIVA. 
 
 Micrococcus. 
 
 Single cocci; never 
 in threads. 
 
 
 Lupus. 
 
 Bacillus. 
 
 Same as Tuberculosis. 
 
 
 Malignant Edema 
 (Gangrenous Sep- 
 ticemia, Vibrio 
 Septique). 
 
 Bacillus. 
 
 Large, slender rods, 
 rounded ends, often 
 in threads; motile, 
 with, flagella and 
 spores; strongly 
 anaerobic. 
 
 Soluble vaccine. 
 
 Mammitis of Cows. 
 
 Micrococcus. 
 
 Oval cocci in chains; 
 streptococci; facul- 
 tatively anaerobic. 
 
 
 Mammitis of 
 Sheep. 
 
 Micrococcus. 
 
 Streptococci and in 
 fours. 
 
 
 Melitensis 
 (Malta Fever). 
 
 Metchnikovi 
 
 Micrococcus. 
 
 Spirillum 
 (vibrio). 
 
 S/x in diameter; occurs 
 singly or in chains 
 of two or more; said 
 to be flagellated. 
 
 Motile spirals with 
 flagella; aerobic. 
 
 An alkaline vaccine 
 which will cause im- 
 munity. 
 
 Neapolitanus. 
 
 Bacillus. 
 
 Small immotile rods, 
 with rounded ends; 
 no spores; faculta- 
 tively anaerobic. 
 
 Produces acids in gel- 
 atin cultures. 
 
 NOMiE. 
 
 Bacillus. 
 
 Small rods, with 
 rounded ends, grow- 
 ing often in long 
 threads. 
 
 
 Ole^. 
 
 Oxytocus perni- 
 
 CIOSUS. 
 
 Bacillus. 
 Bacillus. 
 
 Motile aerobic; does 
 not liquefy gelatin. 
 
 Short rods with round 
 ends. 
 
 Alkali in milk. 
 
 Paratyphoid. 
 
 Bacillus. 
 
 Resembles typhoid 
 bacillus. 
 
 Indol sometimes pro- 
 duced. 
 
 Perfringens. See 
 Pestis. See Bubon 
 
 Aerogenes capsu 
 ic Plague. 
 
 latus. 
 
 
OF THE PRINCIPAL BACTERIA 
 Bacteria. — (Continued.) 
 
 295 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 On blood-serum round 
 
 Causes leprosy in man 
 
 Leprous tissue. 
 
 Hansen. 
 
 white plaques with ir- 
 
 and animals. 
 
 
 
 regular borders. 
 
 
 
 
 Liquefying; growth rap- 
 
 On cornea of rabbits 
 
 Normal human 
 
 Gombert. 
 
 id; colonies on surface. 
 
 .causes slight cloud- 
 
 conjunctiva. 
 
 
 with little radiating 
 
 ing. 
 
 
 
 branches from a dark 
 
 
 
 
 center; those in deep, 
 
 
 
 
 berry-shaped. 
 
 
 
 
 Liquefying; thick center, 
 
 Animals quickly die 
 
 Garden-earth. 
 
 Pasteur. 
 
 radiating periphery; in 
 
 with extensive gan- 
 
 
 
 high culture in test- 
 
 grene and edema. 
 
 
 
 tube, gas-bubbles arise. 
 
 
 
 
 with foul odor. 
 
 
 '. 
 
 
 Not liquefying; brown, 
 
 Causes contagious 
 
 Mammary gland. 
 
 Nocard and 
 
 round granular colon- 
 
 marrrritis in cows: 
 
 
 Mollereau. 
 
 ies; grows slowly; in 
 
 coagulates milk. 
 
 
 
 test-tube, heavy de- 
 
 
 
 
 posit along the needle's 
 
 
 
 
 track. 
 
 
 
 
 Liquefying; round cen- 
 
 Causes contagious gan- 
 
 Found in the milk 
 
 Nocard 
 
 ters with zone of lique- 
 
 grenous mammitis 
 
 of diseased 
 
 
 faction; cone-shaped 
 
 in sheep. 
 
 sheep. 
 
 
 in test-tube. 
 
 
 
 
 Small, round, slightly 
 
 Causes Malta fever. 
 
 Best obtained 
 
 Bruce. 
 
 raised disks; do not 
 
 
 from spleen. 
 
 
 liquefy. 
 
 
 
 
 Grows quickly; colonies. 
 
 Causes vibrion septi- 
 
 Feces of fowls. 
 
 Gamaleia. 
 
 some like cholera As- 
 
 cemia in guinea-pigs 
 
 
 
 iatica, others like chol- 
 
 and pigeons. 
 
 
 
 era nostras; liquefying. 
 
 
 
 
 Not liquefying; thin pearl 
 
 Causes death in some 
 
 Cholera epidemic 
 
 Emmerich. 
 
 like scales in several 
 
 animals; not the 
 
 of Naples, 1884. 
 
 
 layers; wrinkled and 
 
 cause of cholera. 
 
 
 
 mucous layers on po- 
 
 
 
 
 tato. 
 
 
 
 
 Granular spheric colonies 
 
 No action on mice or 
 
 In necrotic tissue 
 
 Schimmel- 
 
 in the deep, fiat on the 
 
 rabbits. 
 
 of noma. 
 
 busch. 
 
 surface; not liquefying; 
 
 
 
 
 growth rapid; best at 
 35° C. 
 
 
 
 
 Whitish growth on cul- 
 
 Causes olive-gall on 
 
 
 Savastano. 
 
 ture-media. 
 
 olive plant. 
 
 
 
 Small yellow granular 
 
 Intravenous injection 
 
 Sour milk. 
 
 Wyssokow- 
 
 colonies; nail-culture 
 
 causes death in mice 
 
 
 itsch. 
 
 in test-tube. 
 
 and rabbits; turns 
 milk acid. 
 
 
 
 Ferments glucose, but not 
 
 Causes continued 
 
 Intestinal con- 
 
 Widal, Gwyn, 
 
 lactose or saccharose; 
 
 fevers. 
 
 tents. 
 
 Schott- 
 
 does not coagulate 
 
 
 
 muUer. 
 
 milk. 
 
 
 
 
296 
 
 CHIEF CHARACTERISTICS 
 
 Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Pneumonia (Pneu- 
 
 Bacillus. 
 
 Short, immotile rods, 
 
 
 mococcus of Fried- 
 
 
 singly or in diplococ- 
 
 
 lander). 
 
 
 ci, surrounded with 
 capsule; no spores; 
 not colored with 
 Gram; facultatively 
 anaerobic. 
 
 
 Pneumonia (Pneu- 
 
 Bacillus. 
 
 Short, oval rods, of- 
 
 .... 
 
 mococcus of Fran- 
 
 
 ten in chains; immo- 
 
 
 kel; Micrococcus 
 
 
 tile ; no spores ; in the 
 
 
 of Pasteur). 
 
 
 tissue surrounded 
 with capsule, col- 
 ored with Gram; 
 facultatively anae- 
 robic. 
 
 
 Pneumonicis 
 
 Bacillus. 
 
 Short, thick motile 
 
 .... 
 
 AGILIS. 
 
 
 rods in pairs. 
 
 
 Proteus septicus. 
 
 Bacillus. 
 
 Slightly curved rods, 
 swelled in portions, 
 sometimes in long 
 threads; motile. 
 
 Foul gas. 
 
 PsiTTACi (perni- 
 
 Micrococcus. 
 
 Streptococci and 
 
 
 ciosus). 
 
 
 zooglea. 
 
 
 Pyocyaneus. 
 
 Bacillus. 
 
 Thin, motile rods; fa- 
 
 Pyocyanin, a non- 
 
 , 
 
 
 cultatively anaero- 
 bic. 
 
 poisonous pigment. 
 
 Pyocyaneus /3. 
 
 Bacillus. 
 
 Forms a brown-yel- 
 low pigment ; other- 
 wise identical with 
 above. 
 
 .... 
 
 Pyogenes (Strepto- 
 
 Micrococcus. 
 
 Streptococci and 
 
 
 coccus erysipela- 
 
 
 zooglea. 
 
 
 tis— Fehleisen). 
 
 
 
 
 Pyogenes albus. 
 
 Micrococcus. 
 
 Staphylococci and 
 streptococci; facul- 
 tatively anaerobic. 
 
 .... 
 
 Pyogenes aureus 
 
 Micrococcus. 
 
 Staphylococci and 
 
 Ptomain, toxalbumin, 
 
 (micrococcus of 
 
 
 zooglea; faculta- 
 
 and pigment. 
 
 osteomyelitis, 
 
 
 tively anaerobic. 
 
 
 Becker). 
 
 
 
 
 Pyogenes citreus. 
 
 Micrococcus. 
 
 Same as Pyogenes au- 
 reus. 
 
 
 Pyogenes fcetidus. 
 
 Bacillus. 
 
 Short motile rods in 
 pairs. 
 
 
 Pyogenes tenuis. 
 
 Micrococcus. 
 
 Cocci without defin- 
 ite arrangement. 
 
 
 Relapsing Fever 
 
 Spirillum. 
 
 Long, wavy spirals; 
 
 
 (Obei-meier). 
 
 
 motile. 
 
 
OF THE PRINCIPAL BACTERIA 
 
 Bacteria. — {Continued.) 
 
 297 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Does not liquefy; grows 
 
 An accompaniment of 
 
 Pneumonic and 
 
 Friedlander. 
 
 quickly; a button-like 
 
 pneumonia, not a 
 
 other sputum, 
 
 
 colony; in test-tube, as 
 
 cause; animals not 
 
 and lung tissue. 
 
 
 if a nail driven in the 
 
 affected. 
 
 
 
 gelatin with head on 
 
 
 
 
 surface. 
 
 
 
 
 Does not liquefy; grows 
 
 Causes pneumonia in 
 
 Sputum of lung 
 
 A. Frankel. 
 
 slowly; small, well-de- 
 
 man, septicemia in 
 
 affections and se- 
 
 
 fined masses; in test- 
 
 animals; also serous 
 
 rous inflamma- 
 
 
 tube, little separate 
 
 inflammations in 
 
 tions. 
 
 
 globules, one above 
 
 man, as pleurisy. 
 
 
 
 the other. 
 
 peritonitis, etc. 
 
 
 
 Liquefying; dark granu- 
 
 Pneumonia in rabbits. 
 
 From rabbits' 
 
 Schon. 
 
 lar colonies; thick sed- 
 
 
 pneumonia. 
 
 
 iment in test-tube. 
 
 
 
 
 Growth rapid; liquefy- 
 
 Fatal for mice in one 
 
 From a child dy- 
 
 Babes. 
 
 ing ; colonies have foul 
 
 to three days. 
 
 ing of intestinal 
 
 
 odor, are small, thick 
 
 
 gangrene. 
 
 
 branches, but soon all 
 
 
 
 
 liquid. 
 
 
 
 
 
 Causes disease in gray 
 
 In blood of par- 
 
 WolfT. 
 
 
 parrots. 
 
 rot's disease. 
 
 
 Liquefying; large, flat 
 
 Fatal for animals; col- 
 
 Pus. 
 
 Gessard. 
 
 colonies with greenish 
 
 ors the dressings 
 
 
 
 fluorescence; on po- 
 
 green. 
 
 
 
 tato, yellow-green 
 
 
 
 
 skin; deeply coloring 
 
 
 
 
 the pulp. 
 
 .... 
 
 .... 
 
 Ernst. 
 
 Not liquefying; round 
 
 Suppuration and sep- 
 
 Pus. 
 
 Rosenbach. 
 
 punctiform colonies; 
 
 ticemia in animals. 
 
 
 
 slow-growing. 
 
 
 
 
 Liquefying; white opaque 
 
 Suppuration and ab- 
 
 Pus. 
 
 Rosenbach. 
 
 colonies. 
 
 scess. 
 
 
 
 Liquefying; small colon- 
 
 Causes abscesses and 
 
 Pus. 
 
 Rosenbach. 
 
 ies with a yellow- 
 
 suppuration in man 
 
 
 
 orange pigment in cen- 
 
 and animals. 
 
 
 
 ter; yeast-like smell; 
 
 
 
 
 a moist layer on potato. 
 
 
 
 
 Colonies, citron-yellow 
 
 .Suppuration. 
 
 Pus. 
 
 Passet. 
 
 color. 
 
 
 
 
 Not liquefying; mucous 
 
 Fatal to animals. 
 
 Pus. 
 
 Passet. 
 
 layer on potato; very 
 
 
 
 
 thick; in test-tube, a 
 
 
 
 
 slicht layer on surface, 
 
 
 
 
 and small points along 
 
 
 
 
 the track. 
 
 
 
 
 On surface, transparent; 
 
 
 Pus of abscesses. 
 
 Rosenbach. 
 
 thin growth; grows 
 
 
 
 
 slowly. 
 
 
 
 
 Cannot be cultivated. 
 
 Causes fever in man 
 
 Blood of man dur- 
 
 Obermeier. 
 
 
 and animals, and is 
 
 ing an attack of 
 
 
 
 the cause of relaps- 
 
 the disease. 
 
 
 
 ing fever. 
 
 
 
298 
 
 CHIEF CHARACTERISTICS 
 
 Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Rhinoscleroma. 
 
 Bacillus. 
 
 See Pneumococcus of 
 
 Friedlander, with 
 
 Sahvarius pyog- 
 enes. 
 
 Micrococcus. 
 
 Very small round coc- 
 ci and staphylococ- 
 ci. 
 
 
 Salivarius septi- 
 cus. 
 
 Salivarius septi- 
 cus. 
 
 Bacillus. 
 Micrococcus. 
 
 Short, immotile rods, 
 encapsulated in 
 pairs, sometimes 
 long chain; aerobic. 
 
 Cocci singly and in 
 zooglea; aerobic. 
 
 : 
 
 Saprogenes No. 
 II. 
 
 Bacillus. 
 
 ■ 
 
 Short rods; faculta- 
 tively anaerobic. 
 
 Foul gas. 
 
 Saprogenes No. 
 III. 
 
 Bacillus. 
 
 Very short rods; fac- 
 ultatively anaero- 
 bic. 
 
 Foul gas. 
 
 Saprogenes fceti- 
 
 DUS. 
 
 Bacillus. 
 
 I mmotile rods; 
 spores. 
 
 Foul gas. 
 
 Senile Gangrene. 
 
 Septicemia after 
 Anthrax. 
 
 Bacilli 
 Micrococcus. 
 
 Thin rods; immotile; 
 
 singly and in pairs; 
 
 ends somewhat 
 
 thickened; aerobic; 
 
 spores. 
 Motile streptococci. 
 
 
 Septicemia of 
 Mice. 
 
 Bacillus. 
 
 Smallest bacillus 
 known; immotile. 
 
 
 Septicemia of 
 Rabbits (Cuni- 
 culicida). 
 
 Septicus acumina- 
 
 TUS. 
 
 Bacillus. 
 Bacillus. 
 
 See Hemorrhagic Septi 
 
 Thin, lancet-shaped 
 rods; very slender. 
 
 cemia. 
 
 Septicus agrig- 
 
 ENUS. 
 
 Bacillus. 
 
 Very short rods. 
 
 .... 
 
 Septicus liquefa- 
 
 CIENS. 
 
 Micrococcus. 
 
 Streptococci and dip- 
 lococci. 
 
 
 
 Septicus ulceris. 
 
 Bacillus. 
 
 1 
 1 
 
 Oval rods; motile. 
 
 Gas; no odor. • 
 
OF THE PRINCIPAL BACTERIA 
 Bacteria. — {Contin tied.) 
 
 299 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 which it is identical. 
 
 
 
 Frischl. 
 
 Slowly liquefying; small 
 
 Locad abscess in ani- 
 
 Saliva. 
 
 Biondi. 
 
 white opalescent col- 
 
 mals. 
 
 
 
 onies. 
 
 
 
 
 Not liquefying; gray cir- 
 
 Fatal to animals. 
 
 Saliva of healthy 
 
 Biondi. 
 
 cular colonies; trans- 
 
 
 persons. 
 
 
 parent zone; in test- 
 
 
 
 
 tube, separated. 
 
 
 
 
 Not liquefying; round 
 
 Fatal to animals. 
 
 Saliva of puer- 
 
 Biondi. 
 
 colonies; separated 
 
 
 peral women. 
 
 
 dots in test-tube. 
 
 
 
 
 Grows quickly; on agar. 
 
 Produces septicemia 
 
 Sweat of feet. 
 
 Rosenbach. 
 
 hyaline drops which 
 
 in rabbits. 
 
 
 
 quickly coalesce, and 
 
 
 
 
 form a mucoid layer 
 
 
 
 
 with a foul odor, that 
 
 
 
 
 of perspiring feet. 
 
 
 
 
 Forms a fluid gray band 
 
 Suppuration in rabbit. 
 
 Putrid marrow of 
 
 Rosenbach, 
 
 on agar; odor of pu- 
 
 
 bone. 
 
 
 trefaction. 
 
 
 
 
 Not Hquelving; thin. 
 
 Rabbits killed with 
 
 Mesenteric glands 
 
 SchotteUus. 
 
 transparent layer; pu- 
 
 large doses. 
 
 of swine with 
 
 
 trid odor. 
 
 
 erysipelas and of 
 healthy swine. 
 
 
 Round yellow colonies; 
 
 Causes gangrene in 
 
 In gangrenous tis- 
 
 Tricomi. 
 
 liquefying in thirty-six 
 
 mice, similar to se- 
 
 sue and blood of 
 
 
 hours; best growth at 
 
 nile gangrene of 
 
 senile gangrene. 
 
 
 37° C. 
 
 man. 
 
 
 
 In bouillon virulence de- 
 
 Septicemia in rabbits. 
 
 Blood of animal 
 
 Charrin. 
 
 stroyed. 
 
 but not in chickens 
 
 dead from an- 
 
 
 
 or guinea-pigs. 
 
 thrax. 
 
 
 Not liquefying; small 
 
 Septicemia in house- 
 
 Putrefying liquids. 
 
 Koch. 
 
 flocculent masses in 
 
 mice, but not field- 
 
 
 
 the deep; grows very 
 
 mice. 
 
 
 
 slowly; in the test- 
 
 
 
 
 tube producing a faint 
 
 
 
 
 cloud. 
 
 
 
 
 At 37° C. on blood-serum 
 
 Pathogenic for rabbits 
 
 Navel stump of 
 
 Babes. 
 
 small transparent 
 
 and guinea-pigs; fev- 
 
 child dead of 
 
 
 plates; later on. turn- 
 
 er; and bacilli in 
 
 septicemia. 
 
 
 ing yellow. 
 
 blood and organs. 
 
 
 
 Not liquefying; brown 
 
 Septicemia in mice 
 
 Earth of recently 
 
 Nicolaier. 
 
 center, a ring, then 
 
 and rabbits. 
 
 plowed fields. 
 
 
 yellow zone. 
 
 
 
 
 Liquefying; a thin gran- 
 
 Pathogenic for mice 
 
 Blood and organs 
 
 Babes. 
 
 ular streak, the surface 
 
 and rabbits, produc- 
 
 of child dying of 
 
 
 sunken in; later, cone- 
 
 ing edema, in the 
 
 septicemia. 
 
 
 like, the walls covered 
 
 serum of which the 
 
 
 
 with leaf-shaped col- 
 
 cocci abound. 
 
 
 
 onies. 
 
 
 
 
 Liquefying; yellow col- 
 
 An ulcer in inoculated 
 
 In blood of child 
 
 Babes. 
 
 onies, taken up with 
 
 animals, followed by 
 
 with gangrenous 
 
 
 gas later on. 
 
 paralysis and death. 
 
 ulcer. 
 
 
300 
 
 CHIEF CHARACTERISTICS 
 
 Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 SePTICUS VESIC/E. 
 
 Bacillus. 
 
 Rods always single; 
 very motile; oval 
 spores. 
 
 
 Smegma. 
 
 Bacillus. 
 
 Slender curved rods, 
 
 
 
 
 identical with what 
 
 • - »• 
 
 
 
 was known as syph- 
 
 
 
 
 ilis bacillus of Lust- 
 
 
 
 
 garten. 
 
 
 Soft Chancre. 
 
 Bacillus. 
 
 Minute oval rods, 
 chiefly in groups or 
 chains. 
 
 
 Sputigenxjm. 
 
 Spirillum. 
 
 Curved, comma- 
 shaped rods; motile. 
 
 
 Subflavus. 
 
 Micrococcus. 
 
 Diplococci like gono- 
 cocci; colored by 
 Gram. 
 
 
 Swine Plague 
 
 Bacillus. 
 
 Motile, oval rods. 
 
 Causes casein precipi- 
 
 (American and 
 
 
 similar to that of 
 
 tate in milk and acid 
 
 French) . 
 
 
 hog cholera. 
 
 formation. 
 
 Sycosiferus fceti- 
 
 Bacillus. 
 
 Short, straight immo- 
 
 On potatoes a foul 
 
 DUS. 
 
 
 tile rods, often in 
 threads. 
 
 odor. 
 
 Syphilis (Spiro- 
 
 Spirocheta. 
 
 Small delicate spirals. 
 
 
 cheta pallida). 
 
 
 dif^cult to stain. 
 
 
 Tetanus. 
 
 Bacillus. 
 
 Large, slender motile 
 
 Ptomains, tetanin. 
 
 
 
 rods, with spores in 
 
 tetanotoxin, spas- 
 
 
 
 one end, drumstick 
 
 motoxin; alsoatox- 
 
 
 
 shape, often in 
 
 albumin. 
 
 
 
 threads; true anae- 
 
 
 
 
 robic. 
 
 
 Tetragenus. 
 
 Micrococcus. 
 
 Large round cells, uni- 
 ted in groups, usual- 
 
 
 
 
 ly of four, and sur- 
 rounded by a cap- 
 sule; immotile; 
 aerobic. 
 
 
 Timothy Grass. 
 
 Bacillus. 
 
 Extremely acid-fast; 
 resembles tubercle 
 bacillus: in cultures 
 may show club for- 
 mation and branches 
 
 
 TOXICATUS. 
 
 Micrococcus. 
 
 Cocci singly and in 
 pairs. 
 
 
OF THE PRINCIPAL BACTERIA 
 Bacteria. — (Continued.) 
 
 301 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Not liquefying; small pin- 
 
 Pathogenic for mice 
 
 In urine of cys- 
 
 Clado. 
 
 head colonies, growing 
 
 and rabbits, produc- 
 
 titis. 
 
 
 slowly; never larger; a 
 
 ing death. 
 
 
 
 brown center, yellow 
 
 
 
 
 periphery. 
 
 
 
 
 Not cultivated. 
 
 
 Normal preputial 
 
 Alvarez and 
 
 
 
 secretions. 
 
 Tavel. 
 
 Has not been cultivated. 
 
 Produces soft chancre. 
 
 In the sore. 
 
 Ducrey. 
 
 Not cultivated. 
 
 Causes death in ani- 
 
 In caries of teeth 
 
 Lewis. 
 
 
 mals. 
 
 and saliva. 
 
 
 Growth slow; liquefying; 
 
 No result on mucous 
 
 Normal secretion 
 
 Bumm. 
 
 on tenth day yellow 
 
 membrane; injected 
 
 of vagina and 
 
 
 points with thready 
 
 under skin, abscess 
 
 urethra. 
 
 
 boundary; on potato, a 
 
 results. 
 
 
 
 brown, thread - like 
 
 
 
 
 growth aftertwo weeks. 
 
 
 
 
 Not liquefying; growth 
 
 Found in American 
 
 Found in capil- 
 
 Billings, 
 
 similar to typhoid 
 
 and French swine 
 
 laries in little 
 
 Rietsch, and 
 
 germ ; on potatoes 
 
 plague, in frog 
 
 emboli; not 
 
 Eberth. 
 
 good growth. 
 
 plague, and Texas 
 
 spread in organs 
 
 
 
 fever- animals af- 
 fected locally. 
 
 of diseased ani- 
 
 
 
 mals. 
 
 
 Slow growth; not liquefy- 
 
 On human skin causes 
 
 From sycosis of 
 
 Tommasoli. 
 
 ing; after four days, lit- 
 
 eruption, vesicular 
 
 the beard. 
 
 
 tle white points, which 
 
 around hairs, then 
 
 
 
 do not change for sev- 
 
 it becomes pustular; 
 
 
 
 eral weeks, then the 
 
 similar to sycosis. 
 
 
 
 superficial ones are 
 
 
 
 
 mucus-like; nail 
 
 
 
 
 growth; on potatoes. 
 
 ^. 
 
 
 
 rapid growth. 
 
 
 
 
 On blood-serum thin 
 
 Supposed to cause 
 
 In tissue and se- 
 
 Schaudinn. 
 
 growth. 
 
 syphilis. 
 
 cretions of syph- 
 ilitics. 
 
 
 Liquefy gelatin slowly; 
 
 Produces tetanus in 
 
 Earth and manure. 
 
 Nicolaier and 
 
 colonies have radiated 
 
 man and animals. 
 
 
 Kitasato. 
 
 appearance; a thorny 
 
 
 
 
 growth along the track 
 
 
 
 
 in test-tube. 
 
 
 
 •« 
 
 Not liquefying; little por- 
 
 Fatal to guinea-pigs 
 
 Found in cavern- 
 
 Gaffky. 
 
 celain-like disks; thick 
 
 and white mice. 
 
 ous phthisical 
 
 
 slimy layer on potato. 
 
 
 lungs. 
 
 
 Colonies visible in thirty- 
 
 May produce tuber- 
 
 Infusions of tim- 
 
 Moeller. 
 
 six hours, scale-like 
 
 cles. 
 
 othy grass. 
 
 
 and grayish white. 
 
 
 
 
 
 Supposed to be the 
 
 Found in the Rhus 
 
 BurriU. 
 
 
 cause of Rhus (pois- 
 
 toxicodendron. 
 
 
 
 on ivy) poisoning. 
 
 
 
302 
 
 CHIEF CHARACTERISTICS 
 
 Pathogenic 
 
 Name. 
 
 Genus. 
 
 Biology. 
 
 Product. 
 
 Tuberculosis. 
 
 Bacillus. 
 
 Slender rods, usually 
 in pairs; not motile; 
 spores not definitely 
 determined ; facul- 
 tatively anaerobic. 
 
 Kochin or paratolin, 
 a glycerin extract of 
 the pure culture (tu- 
 berculin). 
 
 Typhoid. 
 
 Bacillus. 
 
 Slender motile rods, 
 sometimes in 
 threads ; flagella, 
 but no spores; 
 facultatively anae- 
 robic. 
 
 Typhotoxin and 
 toxalbumin. 
 
 Typhoid of Swine 
 
 (swine plague). 
 Tyrogenum. 
 
 Spirillum 
 (vibrio) . 
 
 See Swine Plague. 
 
 Spiral-shaped rods; 
 aerobic. 
 
 .... 
 
 Whooping-cough. 
 
 Bacillus. 
 
 Short oval. 
 
 .... 
 
 Welchii. 
 Xerosis. 
 
 See ASrogenes 
 Bacillus. 
 
 capsulatus. 
 
 Similar to diphtheria 
 bacillus. 
 
 
OF THE PRINCIPAL BACTERIA 
 
 305 
 
 Bacteria. — (Concluded.) 
 
 Culture Characters. 
 
 Actions. 
 
 Habitat. 
 
 Discoverer. 
 
 Grows best on blood-ser- 
 
 Causes tuberculosis, 
 
 In all organs and 
 
 Koch. 
 
 um and glycerin agar 
 
 local and general, in 
 
 secretions of tu- 
 
 
 at 37° C, forming little 
 
 man and lower ani- 
 
 bercular persons. 
 
 
 white crumbs on the 
 
 mals. 
 
 
 
 surface; under micro- 
 
 
 
 
 scope a hairy, matted 
 
 
 
 
 coil is seen; growths 
 
 
 
 
 on potatoes when air- 
 
 
 
 
 tight have been ob- 
 
 
 
 
 tained. 
 
 
 
 
 Not liquefying; little 
 
 Gives rise to enteric 
 
 Found in dejecta 
 
 Eberth. 
 
 whetstone-shaped yel- 
 
 or typhoid fever in 
 
 and spleen and 
 
 
 low colonies inthe deep, 
 
 man. 
 
 urine of typhoid 
 
 
 and leaf-shaped ones 
 
 
 patients. 
 
 
 on the surface; on po- 
 
 
 
 
 tato, a very transpar- 
 
 
 
 
 ent, moist layer. 
 
 
 
 
 Liquefy rapidly; small 
 
 Several animals have 
 
 From old cheese. 
 
 Deneke. 
 
 round colonies; dark 
 
 died from inocula- 
 
 
 
 funnel-shaped liquefac- 
 
 tions. 
 
 
 
 tion in test-tube. 
 
 
 
 
 Blood agar. White 
 
 Produces spasmodic 
 
 Found in whoop- 
 
 Bordet- 
 
 growth on surface. 
 
 cough in animals. 
 
 ing cough. 
 
 Gengou. 
 
 Differs from diphtheria 
 
 
 Found in patho- 
 
 Kuschbert 
 
 bacillus in not produc- 
 
 
 logic conditions 
 
 and 
 
 ing acid in bouillon. 
 
 
 of conjunctiva, 
 sometimes in 
 normal eye. 
 
 Neisser. 
 
INDEX 
 
 Abbe's condenser, 44 
 Achorion schonleinii, 224 
 Acid, boric, 264 
 
 curd cheese, 254 
 
 dyes, 48 
 
 salicylic, 264 
 Acid-fast bacteria, 116 
 Actinomyces, cladothrix, 228 
 
 strep tothrix, 228 
 Actinomycosis, 228 
 Aerobes, 28 
 
 facultative, 28 
 
 obligate, 28 
 Aerobioscope, 234 
 African tick fever, 218 
 Agar, bile salt, MacConkey's, 75 
 
 blood-, 76 
 
 fuchsin-lactose, 77 
 
 glycerin-, 69 
 
 lactose litmus, 72 
 
 nutrient, 71 
 Agar-agar, 69 
 
 Age, influence of, on bacteria, 30 
 Agglutination test for tubercle ba- 
 cilli, 121 
 in cholera, 152 
 in typhoid fever, 140 
 Pfeiffer's cholera, 153, 154 
 Agglutinins, 40 
 Aggressins, 32 
 Air, bacteria in, 232 
 
 Hesse's method of collecting, 
 
 233 
 Petri method of collecting, 
 
 232, 233 
 Sedgwick-Tucker method of 
 
 collecting, 234 
 varieties, 234 
 examination of, 232 
 sewer, bacteria in, 235 
 
 Albumin, blood, solution dried, 78 
 Alcohol, 264 
 
 fermentation, 255 
 Alcoholic solution, saturated, 49 
 Alexin, 40 
 Algae, fission, 21 
 
 Alkaline anilin- water solutions, 51 
 methylene-blue, 50 
 stains, 49 
 Alkaloids, cadaveric, 34 
 Allergy, 42 
 Altered reactivity, 42 
 Alum, 236 
 Amboceptors, 40, 42 
 Amebae, examination for, 199 
 Ammonia production, 245 
 Amoeba coli, 198 
 dysenteriae, 198 
 Anaerobes, 28 
 facultative, 28 
 obligate, 28 
 true, 28 
 Anaerobic bacteria, 180 
 cultivation, 82 
 
 Botkin's method, 84 
 Buchner's method, 84 
 Esmarch's method, 83 
 Frankel's method, 84 
 Hesse's method, 83 
 Liborius's method, 82 
 Park's method, 85 
 Roux's method, 84 
 Wright's method, 85 
 Anaphylaxis, 42 
 Anilin dyes, 47, 264 
 acid, 48 
 basic, 48 
 Anilin-oil, 48 
 water, 49, 50 
 dyes, so 
 
 30s 
 
3o6 
 
 INDEX 
 
 Animal inoculation, 91 
 
 celloidin sacs, 93 
 
 cerebral membranes, 93 
 
 cutaneous, 91 
 
 eye, 92 
 
 guinea-pigs, 91 
 
 intraduodenal, 93 
 
 intraperitoneal, 92 
 
 intratracheal, 93 
 
 intravenous, 92 
 
 methods, 91 
 
 obtaining material after, 94 
 
 subcutaneous, 92 
 Animals as culture-media, 81 
 
 tuberculosis in, 119 
 Anthrax 105 
 
 symptomatic, 187 
 Anthraxin, 109 
 Antiformin method of collecting 
 
 tubercle bacilli, 117 
 Antigens, 41 
 Antisepsis, 261, 262 
 Antiseptics, 261, 262 
 Antistreptococcic bacterins, 166 
 serum, 166 
 vaccines, 166 
 Antitoxic serum, 39 
 
 unit, 133 
 Antitoxin, formation of, accord- 
 ing to lateral-chain theory, 
 
 of diphtheria, 131 
 
 specific action, 38 
 
 tetanus, 183 
 unit for, 183 
 Antituberculous serum, 122 
 Antitj^phoid bacterins, 139 
 
 vaccines, 139 
 Arnold's steam sterilizer, 64 
 Artesian well water, 236 
 Arthrosporous bacteria, 26 
 Artificial cultivation, 62 
 Asbestos, 236 
 Asexual cycle in man, 199 
 Aspergillus flavus, 226 
 
 fumigatus, 226 
 
 glaucus, 226 
 Asporogenic bacteria, 26 
 Autoclave, 64, 65 
 Avicidus bacillus, 193 
 Azofication, 245 
 
 Bacillary dysentery, 199 
 Bacillus acidi lactici, 249 
 
 aerogenes capsulatus, 186 
 
 amylobacter, 251 
 
 amylovorus, 232 
 
 anthracis, 105 
 
 avicidus, 193 
 
 avisepticus, 192 
 
 Boas-Oppler, loi 
 
 botulinus, 144 
 
 bovisepticus, 192 
 
 butyricus, 251 
 
 capsule, of Pfeiffer, 159 
 
 chauvei, 187 
 
 coli, 134 
 
 diagnostic points of, 241 
 
 in milk, Wisconsin test for, 
 
 255 
 
 in urine, 102 
 
 in water, examination for, 240 
 colon, 134 
 
 bacillus typhosus and, differ- 
 entiation, 142 
 comma, of cholera, 148 
 cyanogenes, 251 
 diphtheria, 126 
 
 products of, 131 
 dysenteriae, 145, 199 
 
 products, 147 
 enteritidis, 135 
 
 sporogenes, 187 
 fluorescens, 171 
 hay, TOO 
 icteroides, 219 
 Klebs-LofiEler 126, 
 Koch-Weeks, 161 
 lactis aerogenes, 249 
 lepra, 122 
 mallei, 124 
 megaterium, 99 
 melitensis, 162 
 mesentericus vulgatus, 98 
 Milzbrand, 105 
 murisepticus, 195 
 mycoides, 99 
 oedematis, 184 
 
 maligni, 184 
 of anthrax, 105 
 of bluish-green pus, 171 
 of bubonic plague, 190 
 of chancroid, 178 
 
INDEX 
 
 307 
 
 Bacillus of chicken cholera, 193 
 of cholera, 148 
 of diphtheria, 126 
 
 products, 131 
 of dysentery, 145 
 
 products, 146 
 of enteric fever, 135 
 of erysipelas of swine, 194 
 of fowl septicemia, 193 
 of glanders, 1 24 
 of influenza, 160 
 of lepra, 122 
 
 of malignant pustule, 105 
 of pertussis, 161 
 of phlegmonous emphysema, 
 
 186 
 of rhinoscleroma, 159 
 of soft chancre, 178 
 of splenic fever, 105 
 of symptomatic anthrax, 187 
 of tetanus, 180 
 of typhoid fever, 135 
 paracolon, 143 
 paratyphoid, 143 
 perfringens, 187 
 pestis, 190 
 pneumoniae, 159 
 potato, of Fliigge, 98 
 proteus vulgaris, 147 
 pyocyaneus, 171 
 ramosus, 99 
 root, 99 
 rotz-, 124 
 
 saccharobutyricus, 187 
 Shiga, 199 
 smegma, 123 
 subtilis, 100 
 suipestifer, 133 
 suisepticus, 192 
 tubercle, no 
 
 products of, 1 20 
 tuberculosis, no 
 
 products of, 1 20 
 typhosus, 135 
 
 colon bacillus and, differentia- 
 tion, 142 
 
 from blood, 143 
 
 in water, 138 
 
 diagnostic points, 242 
 
 products, 139 
 violaceus, 102 
 
 Bacillus vulgatus, 98 
 
 Welchii, 186 
 
 Wurzel, 99 
 
 X, 219 
 Bacteremia, 33 
 Bacteria, acid-fast, 116 
 
 aerobic, 28 
 
 anaerobic, 28, 180 
 cultivation of, 82 
 Botkin's method, 84 
 Buchner's method, 84 
 Esmarch's method, 83 
 Frankel's method, 84 
 Hesse's method, 83 
 Liborius's method, .82 
 Park's method, 85 
 Roux's method, 84 
 Wright's method, 85 
 
 and soil fertility, 244 
 
 arthrosporous, 26 
 
 asporogenic, 26 
 
 avenues of entrance, 32 
 
 biologic activities, 26, 28 
 
 Brownian movements, 23 
 
 causing disease, 29 
 
 chemic activities, 26 
 composition, 22 
 products, 29 
 
 chief characteristics, 268-303 
 
 cholera, 148 
 
 classification, 22 
 
 colonies of, growth and appear- 
 ances, 87 
 
 colon-typhoid group, 133 
 
 cultivation, 62 
 
 defenses to invasion, 34 
 
 development of, 21 
 
 diseases from, 29 
 
 distribution, 26 
 
 effects of, general, 33 
 local, ss 
 
 endosporous, 24 
 
 facultative, 27 
 
 fermentation by, 29 
 
 filterable, 218 
 
 fluorescence of, 30 
 
 gas-forming, 30 
 
 general effects, $^ 
 
 growth of, 27 
 
 how cause disease, 30 
 
 in air, 232 
 
3o8 
 
 INDEX 
 
 Bacteria in air, Hesse's method of 
 collecting, 233 
 
 Petri method of collecting, 
 232, 233 
 
 Sedgwick-Tucker method of 
 collecting, 234 
 
 varieties, 234 
 in artesian well water. 236 
 in blood, 260 
 in butter, 254 
 in buttermilk, 255 
 in cheese, 254 
 in condensed milk, 255 
 in conjunctiva, 258 
 in cream, 248 
 in ear, 259 
 in feces, 260 
 in filtered water, 236 
 in food, 246 
 
 in geni to-urinary passages, 260 
 in ice-cream, 248 
 in intestine, 259 
 in milk, 246, 249 
 in mouth, 258 
 in nasal cavity, 259 
 in pneumonia, 155 
 in sewer air, 235 
 in skin, 257 
 in soil, 232, 243 
 in stomach, 259 
 in urethra, 260 
 in urine, 102, 260 
 in vagina, 260 
 
 in water, method of examination, 
 2_38_ 
 
 varieties, 238 
 in well water, 236 
 infective, 33 
 influence of age on, 30 
 
 of electricity on, 28 
 
 of heat on, 28 
 
 of light on, 28 
 
 of moisture on, 28 
 
 of oxygen on life and growth 
 of, 27 
 
 of Rontgen rays on, 28 
 
 of temperature on life and 
 growth, 27 
 local effects, 33 
 locomotion, 23 
 methods of studying, 43 
 
 Bacteria, nitrification by, 29 
 
 non-pathogenic, 29 
 table of, 268-287 
 
 odors from, 30 
 
 of hemorrhagic septicemia, 192 
 
 origin, 26 
 
 oxidation by, 29 
 
 parasitic, 27 
 
 pathogenic, 29, 97 
 table of, 287-303 
 
 phosphorescence by, 30 
 
 pigmentation by, 30 
 
 plant diseases due to, 231 
 
 pyogenic, 33 
 
 quantity of, infection depend- 
 ing on, 32 
 
 reduction by, 29 
 
 reproduction, 24 
 
 sewage, examination for, 240 
 
 specific, ss 
 nature, 27 
 
 spore contents, 25 
 formations, 24 
 
 staining of, 47 
 
 structure of, 21, 22 
 
 suppurative, 33 
 
 tables of, 268-303 
 
 types, 21 
 
 ultra-microscopic, 218 
 
 unstained, examination of, 45 
 
 vibratory movements, 23 
 Bacterial vaccines, 95 
 
 treatment of sewage, 243 
 Bactericides, 41 
 Bactericie du charbon, 105 
 Bacterins, 95 
 
 anticholera, 153 
 
 antistreptococcic, 166 
 
 antityphoid, 139 
 
 counting of, 96 
 
 preparation of, 95 
 
 standardization of, 95 
 Bacteriologic examination of or- 
 gans and cavities, 257 
 Bacteriolysins, 41 
 Bacterium acidi lactici, 249 
 
 bulgaricum, 250 
 
 caucasicus, 250 
 
 coH commune, 134 
 
 guntheri, 250 
 
 lactis acidi, 250 
 
INDEX 
 
 309 
 
 Bacterium prodigiosum, 97 
 as cancer remedy, 98 
 saccharobutyricus, 251 
 syncyanum, 251 
 termo, 147 
 tumefaciens, 232 
 Zopfii, 100 
 
 Basic dyes, 48 
 
 Beer fermentation, 256 
 
 Beggiatoa alba, 228 
 
 Bichlorid of mercury, 62 
 
 Biedert's method of collecting 
 tubercle bacilli, 116 
 
 Bile, lactose-, 76 
 salt agar, MacConkey's, 75 
 
 Biologic activities, 26, 28 
 
 Black-leg, 187 
 
 Blastomyces, 223 
 
 Blastomycetes, 220, 222 
 
 Blastomycetic dermatitis, 223 
 
 Blender, 44 
 
 Blood albumin, solution dried, 78 
 bacillus typhosus from, 143 
 bacteria in, 260 
 coagulum, 74 
 cultures, 261 
 specimens, staining, 57, 261 
 
 Blood-agar, 76 
 
 Blood-serum, 69 
 coagulation of, 72 
 human, preparation of, 74 
 mixture, Loflfler's 74 
 nutrient, preparation of, 72 
 preservation, in liquid state, 74 
 sterilization of, 73 
 test, Gruber-Widal, 140 
 
 Bluish-green pus, bacillus of, 171 
 
 Boas-Oppler bacillus, loi 
 
 Boiled eggs, 78 
 
 Boiling as means of purifying wa- 
 ter, 238 
 
 Bordet's cholera test, 155 
 
 Borer, Frankel's, 244 
 
 Boric acid, 264 
 
 Botkin's method of cultivating an- 
 aerobic bacteria, 84 
 
 Bouillon filtrate, Denys', 120 
 guinea-pig, 78 
 
 Bovine farcin du boeuf, 231 
 tuberculosis, human tuberculo- 
 sis and, relation, 119 
 
 Bowhill's orcein stain, 60 
 
 Bread mash, 69 
 
 Brill's disease, 219 
 
 Broth, nitrate, 70, 71 
 nutrient, 71 
 sugar, 71 
 
 Brownian movements, 23 
 
 Bubonic plague, 190 
 
 Buchner's method of cultivating 
 anaerobic bacteria, 84 
 
 Budding fungi, 220 
 
 Buerger's method of staining cap- 
 sule, 61 
 
 Butter, bacteria in, 254 
 
 Buttermilk, bacteria in, 255 
 
 Cadaveric alkaloids, 34 
 
 Calmette's ophthalmic tuberculin 
 reaction, 121 
 
 Cancer remedy, bacterium prodigi- 
 osum as, 98 
 
 Capsule bacillus of Pfeiffer, 159 
 of spore, 25 
 stain, 61 
 
 Buerger's method, 61 
 Hiss' method, 52, 61 
 of Welch, 53 
 
 Carbolfuchsin, 49 
 
 Carbolthionin stain, 52 
 
 Carriers, cholera, 153 
 typhoid, 139 
 
 Catarrhal conjunctivitis, 258 
 
 Cattle-fever, Texas, 208 
 
 Cell-contents, 22 
 
 Celloidin sacs for animal inocula- 
 tion, 93 
 
 Cell-wall, 22 
 
 Cerebral membranes, animal in- 
 oculation by, 93 
 
 Cerebrospinal meningitis, epi- 
 demic, 177 
 
 Chancre, soft, 178 
 
 Chancroid, 178 
 
 Charbon symptomatique, 187, 189 
 
 Charcoal sponge, 236 
 
 Cheese, bacteria in, 254 
 
 Chemic activities, 26 
 composition, 22 
 products of bacteria, 29 
 
 Chicken cholera, 193 
 
3IO 
 
 INDEX 
 
 Chlorin, 264 
 Cholera, 148 
 
 bacteria, 148 
 
 carriers, 153 
 
 chicken, 193 
 
 comma bacillus of, 148 
 
 hog, 133 
 
 red, 152 
 Chromatin stain, Wright's, for ma- 
 larial organisms, 204 
 Chromium trioxid for staining 
 
 spores, 60 
 Cladothrices, 227 
 Cladothrix actinomyces, 228 
 
 dichotoma, 227 
 Classification, 22 
 Clostridium butyricum, 251 
 Coagulating ferments, 30 
 Coagulation of blood-serum, 72 
 Coagulum, blood, 74 
 Cocci, pyogenic, 163 
 Coley's fluid, 166 
 Colitis contagiosa, 135 
 Colon bacillus, 134 
 
 bacillus typhosus and, differ- 
 entiation, 142 
 Colon-typhoid group, 133 
 Colonies, growth and appearances, 
 
 . ^7 . 
 
 impression of, 88 
 
 macroscopic appearance, 87 
 
 microscopic appearance, 88 
 Combinor, 42 
 
 Comma bacillus of cholera, 148 
 Complement, 40, 42 
 
 deviation of, 42 
 
 fixation of, 42 
 Completor, 42 
 
 Concentrated staining solutions, 48 
 Condensed milk, bacteria in, 255 
 Condenser, Abbe's, 44 
 Conjunctiva, bacteria in, 258 
 Conjunctivitis, catarrhal, 258 
 
 diplobacillus of, 171 
 
 epidemic, 161 
 Conradi-Drigalski medium, 76 
 Copper sulphate, 264 
 Copula, 40 
 
 Corrosive sublimate, 262 
 Cotton plugs or corks, 66 
 Cover-glass preparations, 54 
 
 Cream, classification of, 248 
 Crenothrix kiihniana, 227 
 Cresols, 264 
 Crown gall, 232 
 Cultivation, 62 
 artificial, 62 
 
 of anaerobic bacteria, 82 
 Botkin's method, 84 
 Buchner's method, 84 
 Esmarch's method, 83 
 Frankel's method, 84 
 Hesse's method, 83 
 Liborius's method, 82 
 Park's method, 85 
 Roux's method, 84 
 Wright's method, 85 
 Culture-media, inoculation of, 78 
 nutrient, preparation of, 67, 70 
 reaction, 70 
 solid transparent, 69 
 sterilization of, 62, 70 
 Cultures, blood, 261 
 fresh egg, 77 
 glass slide, 78 
 plate, 79 
 
 pure, by boiUng, 81 
 rolled, 80 
 stab, 78 
 stroke, 78 
 test-tube, 78 
 thrust, 78 
 Cutaneous inoculation of animals, 
 
 91 
 Cutting sections, 56 
 Cytase, 40 
 Cytolysins, 40 
 Cytolytic serum, 40 
 
 Decolorizing agents, 49 
 
 Denitrification, 245 
 
 Denys' B. F. tuberculin, 120 
 
 Deodorants, 262 
 
 Dermatitis, blastomycetic, 223 
 
 Dermo-tubercuHn reaction of von 
 
 Pirquet, 121 
 Desmon, 40 
 Development, 21 
 Deviation of complement, 42 
 Diastatic ferments, 29 
 
INDEX 
 
 3" 
 
 Dieudonne's medium, 77 
 
 for spirillum cholerae, 151 
 Diphtheria, 126 
 
 antitoxin of, 131 
 
 methods of diagnosis, 130 
 
 Neisser's stain for, 5 2 
 
 streptococcus in, 133 
 
 toxins of, 131 
 Diplobacillus of conjunctivitis, 
 
 171 
 Diplococcus intracellularis men- 
 ingitidis, 177 
 
 lanceolatus, 157 
 
 pneumoniae, 155, 157 
 Discharges, disinfection of, 265 
 Disinfectants, 62, 262 
 
 testing value of, 265 
 Disinfection, general measures for, 
 265 
 
 of discharges, 265 
 Distribution, 26 
 Dourine, 204 
 Dry heat, 64 
 Drying specimens, 54 
 Dum-dum fever, 208 
 Dunham's modified peptone wa- 
 ter, 77 
 
 peptone solution for spirillum 
 cholerae, 150 
 
 rosalic acid solution, 77 
 Dyes, acid, 48 
 
 aniUn, 47, 264 
 
 anilin-oil water, 50 
 
 basic, 48 
 Dysentery, 145, 198 
 
 bacillary, 199 
 
 Ear, bacteria in, 259 
 
 Edema, malignant, 184 
 
 Eggs, boiled, 78 
 fresh, cultures, 77 
 
 Ehrlich's lateral-chain theory of 
 immunity, 36 
 
 Electricity, influence of, on bac- 
 teria, 28 
 
 Eisner's typhoid medium, 76 
 
 Emphysema, phlegmonous, 186 
 
 Emphysematous gangrene, 186 
 
 Endo medium, 77 
 
 Endogenous infection, 31 
 
 Endosporous bacteria, 24 
 
 Entamoeba histolytica, 198 
 
 Enteric fever, 135 
 
 Epidemic cerebrospinal meningi- 
 tis, 177 
 conjunctivitis, 161 
 
 Erysipelas, 164 
 of swine, 194 
 
 Esmarch's cubes, 68 
 method of cultivating anaerobic 
 
 bacteria, 83 
 tubes, 80 
 
 Estivo-autumnal form of mala- 
 rial protozoa, 201 
 
 Exogenous infection, 31 
 
 Extracellular toxins, 31 
 
 Eye, inoculation of animals by, 
 92 
 
 Facultative aerobes, 28 
 
 anaerobes, 28 
 
 bacteria, 27 
 Farcin du boeuf, bovine, 231 
 Farcy-buds, 125 
 Fat-splitting ferments, 30 
 Favus, 225 
 Feces, bacteria in, 260 
 
 cholera bacteria in, 153 
 Fermentation, 29 
 
 alcohol, 255 
 
 beer, 256 
 
 tube, 81 
 
 vinegar, 255 
 Ferments, 29 
 
 coagulating, 30 
 
 diastatic, 29 
 
 fat-splitting, 30 
 
 hydrolytic, 30 
 
 inverting, 29 
 
 proteolytic, 29 
 Fertility, soil, bacteria and, 244 
 Filter materials, 236 
 
 Pasteur-Chamberland, 237 
 
 Petri's sand, 233 
 Filterable organisms, 218 
 Filtered water, 236 
 Filters, 67 
 Filtration, 265 
 
 sterilization by, 67 
 Finkler-Prior vibrio, 154 
 
312 
 
 INDEX 
 
 Fishing, 88 
 Fission algae, 21 
 
 fungi, 21 
 Fixateur, 40 
 
 Fixation of complement, 42 
 Flagella, 23 
 
 Loffler's mordant for, 51 
 
 stain, with Loffler's mordant, 61 
 Flagellates, 197 
 
 Flask to receive blood-serum, 72 
 Fliigge's potato bacillus, 98 
 Fluorescence, 30 
 Food, bacteria in, 246 
 Foods as source of infection, 255 
 Foot, Madura, 230 
 Formaldehyd, 263 
 
 solid, 264 
 Fowl septicemia, 193 
 Fractional steriHzation of Tyn- 
 
 dall, 65 
 Frankel's borer, 244 
 
 method of cultivating anaerobic 
 bacteria, 84 
 of staining tubercle bacilli, 115 
 
 pneumococcus, 157 
 Fresh egg cultures, 77 
 Fuchsin-lactose-agar, 77 
 Fungi, budding, 220 
 
 fission, 21 
 
 ray-, 228 
 
 staining, Unna's method, 61 
 
 thrush, 222 
 
 Gabbet's acid blue, 51 
 
 modification of Frankel's method 
 of staining tubercle bacilH, 115 
 Gametes, 200 
 
 Gangrene, emphysematous, 186 
 Gangrenous mastitis of sheep, 196 
 Gas phlegmons, 186 
 Gas-formati©n, 30 
 Gelatin, 69 
 
 nutrient, 71 
 
 potato, 76 
 Gelatinous membrane, 22 
 Genito-urinary passages, bacteria 
 
 in, 260 
 Germicides, 261, 262 
 Germination, 25 
 Giemsa's stain, 53 
 
 Glanders, 124 
 
 Glass plating, 80 
 slide cultures, 78 
 
 Glossina morsitans, 208 
 palpalis, 208 
 
 Glycerin-agar, 69 
 
 Gonococcus, 174 
 allied varieties, 176 
 Neisser, 174 
 Neisser's stain for, 175 
 Wertheim's medium for, 78 
 
 Gram's iodin solution, 51 
 
 method of double staining, 58 
 of tissue staining, 58 
 
 Granulobacillus immobihs, 187 
 
 Growth, 27 
 
 Gruber-Widal blood-serum test, 
 140 
 
 Guinea-pig bouillon, 78 
 
 Guinea-pigs, 91 
 
 Giinther's stain for blood speci- 
 mens, 261 
 
 Hands, sterilization of, 264 
 Hanging block, 47 
 
 drop, 46 
 Haptophore group, 37 
 Hay bacillus, 100 
 Heat, 49 
 
 as disinfectant, 63 
 
 as germicide, 262 
 
 dry, 64 
 
 influence of, on bacteria, 28 
 
 moist, 64 
 Hemolysins, 41 
 Hemolysis, 41 
 Hemorrhagic septicemia, 190 
 
 bacteria of, 192 
 Herpes tonsurans, 225 
 Herpetomonas, 208 
 Hesse's medium for t3rphoid, 75 
 
 method of collecting bacteria 
 from air, 233 
 of cultivating anaerobic bac- 
 teria, 83 
 Hiss' capsule stain, 52, 61 
 
 medium for plating, 75 
 Hoffman, pseudobacillus of, 129 
 Hog cholera, 133 
 Homogeneous system, 43 
 
INDEX 
 
 313 
 
 Host, susceptibility of, 33 
 Hot-air sterilizer, 63 
 Hueppe's fresh egg cultures, 77 
 Hydrogen dioxid, 264 
 Hydrolytic ferments, 30 
 Hydrophobia, 209 
 Hygienic laboratory phenol coeffi- 
 cient, 265 
 Hypersensitiveness, 42 
 Hypersusceptibility, 42 
 Hyphomycetes, 223 
 
 Ice cream, 248 
 Immunity, 34, 35 
 acquired, 35 
 active, 35 
 passive, 36 
 Ehrlich's lateral-chain theory, 
 
 36 
 from intentional infection or in- 
 toxication, 35 
 lock and key theory, 39 
 Metchnikoff 's phagocytic theory 
 
 of, 36 
 natural, 35 
 theories of, 36 
 unit, 133 
 Impression of colonies, 88 
 Incubator, 74 
 Index, opsonic, 41 
 
 negative phase, 41 
 positive phase, 41 
 India ink method of identifying 
 
 spirochseta pallida, 211 
 Indol reaction in cholera, 152 
 Infantile paralysis, epidemic, 218, 
 
 219 
 Infection, 30, 31 
 avenues of, 1,2 
 cardinal conditions for, 32 
 depending on quantity of bac- 
 teria, 32 
 endogenous, 31 
 exogenous, 31 
 foods as source of, 255 
 mixed, 33 
 pathogenesis, 31 
 sources of, 31 
 susceptibility to, 33 
 virulence of, 32 
 
 Infective bacteria, 33 
 Influenza, 160 
 Infusoria, 197, 198 
 Inoculating potatoes, manner of, 
 ■ 68 
 
 Inoculation, animal, 91. See also 
 Animal inoculation. 
 of culture-media, 78 
 Insecticides, 263 
 Insoluble toxins, 31 
 Inspissator for blood-serum, 73 
 Instruments, sterilization of, 45 
 Intensifiers, 48 
 Intestine, bacteria in, 259 
 Intracellular toxins, 31 
 Intraduodenal animal inoculation, 
 
 93 
 
 Intraperitoneal injections of ani- 
 mals, 92 
 
 Intratracheal inoculation of ani- 
 mals, 93 
 
 Intravenous injections of animals, 
 92 
 
 Inverting ferments, 29 
 
 lodin, 264, 265 
 
 as used in Gram's method, 49 
 solution, Gram's, 51 
 
 Iris blender, 44 
 
 Jackson bile media, 242 
 Jenner's stain, 53 
 
 for malarial organisms, 203 
 
 Kala-azar, 208 
 
 King's solution dried blood albu- 
 min, 78 
 
 Klatsch preparations, 88 
 
 Klebs-Loffler bacillus, 126 
 
 Klein's method of staining spores, 
 60 
 
 Koch's alkaline methylene-blue, 50 
 bacillen emulsion, 120 
 rules in regard to bacterial cause 
 of disease, 94 
 
 Koch- Weeks bacillus, 161 
 
 Kiihne's method of staining spores,. 
 60 
 
 stam, 51 
 
314 
 
 INDEX 
 
 Laboratory, small requirements 
 
 of, 85 
 Lactose litmus agar, 72 
 Lactose-bile, 76 
 Lateral-chain theory of immunity, 
 
 Ehrlich's 36 
 Law, Weigert's, 38 
 Leishman-Donovan bodies, 208 
 Leishman's stain, 53 
 Lens, oil-immersion, 43 
 Lepra bacillus, 122 
 Leprosy, 122 
 Leptothrix buccalis, 228 
 
 gigantea, 228 
 
 innominata, 228 
 
 maxima, 228 
 Liborius's method of cultivating 
 
 anaerobic bacteria, 82 
 Life cycle of malarial sporozoa, 
 199 
 
 of protozoa, 198 
 Light, influence of, on bacteria, 28 
 Lime, 265 
 
 Litmus agar, lactose, 72 
 Lock and key theory of immunity, 
 
 39 
 Locomotion, 23 
 
 Loflfler's alkaline methylene-blue, 
 50 
 
 blood-serum mixture, 74 
 
 mordant for flagella, 51, 61 
 
 stain for tissues, 59 
 Luetin reaction, 216 
 Lye, soda, 263 
 Lysis, 42 
 
 MacConkey's bile salt agar, 75 
 Macrocytase, 36 
 Macrogamete, 201 
 Macrophages, 36 
 Madura foot, 230 
 Mai de pis, 196 
 
 Malarial organisms, methods of 
 examination for, 203 
 protozoa, estivo-autumnal form, 
 201 
 forms of, 201 
 quartan form, 201 
 tertian form, 201 
 sporozoa, life cycle of, 199 
 
 Malignant edema, 184 
 
 pustule, 105 
 
 tertian form of malarial pro- 
 tozoa, 201 
 Mallein, 126 
 Malta fever, 162 
 Mash, bread, 69 
 
 potato, 68 
 Mastigophora, 197 
 Mastitis, gangrenous, of sheep, 196 
 Measles, 219 
 Media, culture-, inoculation of, 
 
 nutrient, preparation of, 67 
 preparation of, 70 
 reaction of, 70 
 solid transparent, 69 
 sterilization of, 70 
 Mediterranean fever, 162 
 Membrane, gelatinous, 22 
 Meningitis, epidemic cerebro- 
 spinal, 177 
 Meningococcus, 174, 177 
 Mercuric chlorid, 262 
 Mercury, bichlorid of, 62 
 Merozoites, 199 
 Metals, salts of, 263, 264 
 MetchnikofT's theory of immunity, 
 
 36 
 Methylene-blue, alkaline, 50 
 Microbe en huit, 193 
 Micrococcus albicans, 176 
 
 cereus albus, 169 
 fiavus, 169 
 
 cholera gallinarum, 193 
 
 citreus, 176 
 
 gonorrhoeae, 174 
 
 melitensis, 162 
 
 meningitidis, 177 
 
 of mal de pis, 196 
 
 of sputum septicemia, 157 
 
 pyogenes citreus, 169 
 tenuis, 169 
 
 subflavus, 176 
 
 tetragenus, 170 
 
 ureae, 102 
 Microcytase, 36 
 Microgametes, 201 
 Microphages, 36 
 Microscope, 43 
 Microsporon furfur, 224, 226 
 
INDEX 
 
 315 
 
 Milk as source of contagion, 253 
 
 bacillus coli in, Wisconsin test 
 for, 255 
 
 bacteria in, 246, 249 
 
 classification of, 247 
 
 condensed, bacteria in, 255 
 
 culture-medium, 77 
 
 examination of, 252 
 for tubercle bacilli, 116 
 
 pasteurized, 247, 253 
 
 pure, 246 
 
 raw, 247 
 
 red, 252 
 
 yellow, 252 
 Milzbrand bacillus, 105 
 Mixed infection, ;^^ 
 Moist heat, 64 
 
 Moisture, influence of, on bac- 
 teria, 28 
 Molds, 220, 221 
 
 examination of, 226 
 
 true, 223 
 Morax-Axenfeld diplobacillus of 
 
 conjunctivitis, 171 
 Mordant, Loffler's, for flagellaj 51 
 
 for flagella, 61 
 Mordants, 48 
 
 Moro's tuberculin test, 121 
 Mouse septicemia, 195 
 Mouth, bacteria in, 258 
 
 white, 222 
 Mucor mucedo, 224 
 Mycetoma, 230 
 Mycobacterium tuberculosis, no 
 
 Nagana, 204, 206 
 Naphthahn, 264 
 Nasal cavity, bacteria in, 259 
 NeedlQs, platinum, 45 
 
 sterilization of, 79 
 Negri bodies, 209 
 Neisser's gonococcus, 174 
 
 stain for diphtheria, 52 
 for gonococcus, 175 
 NicoUe's stain, 52 
 Nitiagin, 246 
 Nitrate broth, 70, 71 - 
 Nitrification, 245 
 
 by bacteria, 29 
 Nitro-bacterine, 246 
 
 Nocardia farcinica, 231 
 Noguchi's luetin reaction, 216 
 Novy's jars, 85 
 Nutrient agar, 71 
 
 blood-serum, preparation of, 72 
 
 broth, 71 
 
 culture-media, preparation, 67, 
 70 
 
 gelatin, 71 
 
 Obligate aerobes, 28 
 
 anaerobes, 28 
 Odors from bacteria, 30 
 Oidiomycosis, 223 
 Oidium, 221, 223 
 
 albicans, 222 
 
 coccidioides, 223 
 
 lactis, 222 
 Oil-immersion lens, 43 
 Oocysts, 201 
 Ophthalmic tuberculin reaction of 
 
 Calmette, 121 
 Opsonic index, 41 
 
 negative phase, 41 
 positive phase, 41 
 Opsonins, 41 
 
 Orcein stain, Bowhill's, 60 
 Origin, 26 
 
 Oxidation by bacteria, 29 
 Oxygen, influence of, on life and 
 
 growth of bacteria, 27 
 
 Pappenheim's method for staining 
 tubercle bacilli in urine, 115 
 
 Paracolon bacillus, 143 
 
 Paralysis, epidemic infantile, 218, 
 219 
 
 Parasites, 27 
 
 Parasitic bacteria, 27 
 thrush, 222 
 
 Paratyphoid bacilU, 143 
 
 Park's method of cultivating an- 
 aerobic bacteria, 85 
 
 Pasteur-Chamberland filter, 237 
 
 Pasteurized milk, 247, 253 
 
 Pathogenic bacteria, 29, 97 
 table of, 287-303 
 yeasts, 222 
 
 Pear blight, 232 
 
3i6 
 
 INDEX 
 
 Penicillium glaucum, 223 
 Peptone water, modified Dunham, 
 
 77 
 Pertussis, 161 
 Pest, 190 
 Petri dish, 80 
 
 method of collecting bacteria 
 from air, 232, 233 
 
 sand-filter, 233 
 Pfeiffer's capsule bacillus, 159 
 
 cholera reaction and agglutina- 
 tion, 153, 154 
 Phagocytes, 36 
 Phagocytic theory of immunity, 
 
 Metchnikoff's, 36 
 Phenol, 263 
 
 coefficient, Hygienic Labora- 
 tory, 265 
 
 solutions, 50 
 Phlegnjonous emphysema, 186 
 Phlegmons, gas, 186 
 Phosphorescence, 30 
 Pigmentation, 30 
 Pink eye, 161, 258 
 Piroplasma bigeminum, 208 
 
 bovis, 208 
 
 hominis, 209 
 Pityriasis versicolor, 226 
 Plague, bubonic, 190 
 Plant diseases due to bacteria, 231 
 Plants, splitting, 21 
 Plasmodium falciparum, 201 
 
 malariae, 201 
 
 vivax, 201 
 Plate cultures, 79 
 
 method of examining milk for 
 bacteria, 253 
 Plating, glass, 80 
 
 streaked surface, 79 
 Platinum needles, 45 
 Pneumococcus, 157 
 
 Frankel's, 157 
 Pneumonia, 155 
 
 bacteria in, 155 
 Poliomyelitis, infantile, 218, 219 
 Potassium iodid medium, 76 
 
 permanganate, 264 
 Potato as culture-media, 67 
 
 as medium, 67 
 
 bacillus of Fliigge, 98 
 
 mash, 68 
 
 Potatoes, manner of inoculating, 
 68 
 
 test-tube. 68 
 Potato-gelatin, 76 
 Precipitin serum, 40 
 Precipitins, 39 
 
 Prescott-Breed method of exam- 
 ining milk for bacteria, 252 
 Preservatives, 262 
 Protein contents of bacterial cell, 
 
 29 
 Proteolytic ferments, 29 
 Proteus mirabilis, 147 
 
 Zenkeri, 148 
 Protozoa, 197 
 
 life-cycle of, 198 
 
 malarial, estivo-autumnal form, 
 201 
 forms of, 201 
 quartan form, 201 
 tertian form. 201 
 Pseudobacillus of Hoffman, 129 
 Pseudodiphtheria, 129 
 Ptomains, 29, 34 
 Puerperal fever, 165 
 Pure cultures by boiling, 81 
 Pus, bluish-green, bacillus of, 171 
 Pustule, malignant, 105 
 Putrefaction, 30 
 Pyemia, 33 
 Pyocyanin, 173 
 Pyogenic bacteria, 33 
 
 cocci, 163 
 
 Quartan form of malarial pro- 
 tozoa, 201 
 Quarter-evil, 187 
 
 Rabies, 209 
 
 RauschlDrand, 187, 189 
 
 Ray-fungus, 228 
 
 Reaction. See Test. 
 of culture-media, 70 
 
 Reactivity, altered, 42 
 
 Receptors, 36 
 free, 41 
 
 of first order, 36 
 of second order, 36 
 of third order, 37 
 
INDEX 
 
 317 
 
 Red milk, 252 
 
 Reduction by bacteria, 29 
 
 Relapsing fever, 217 
 
 Removing excess of stain, 55 
 
 Rennet curd cheese, 255 
 
 Reproduction, 24 
 
 Rhinoscleroma, 159 
 
 Rideal-Walker standard for dis- 
 infectants, 265 
 
 Ring- worm, 225 
 
 Rolled cultures, 80 
 
 Romanowsky's stain, 53 
 
 Rontgen rays, influence of, on bac- 
 teria, 28 
 
 Root bacillus, 99 
 
 Rosalie acid solution, Dunham's, 
 
 77 
 Rotz-bacillus, 124 
 Rouget du pore, 194 
 Roux's double stain, 52 
 
 method of cultivating anaerobic 
 bacteria, 84 
 
 test-tube, 68 
 
 Saccharomyces albicans, 221 
 cerevisiae, 220 
 mycoderma, 221 
 niger, 221 
 rosaceus, 221 
 
 Saccharomycetes, 220 
 
 Salicylic acid, 264 
 
 Salts of metals, 263, 264 
 
 Sand-filter, Petri's, 233 
 
 Saprophytes, 27 
 
 Sarcina, 103 
 aurantica, 104 
 lutea, 103 
 ventriculi, 104 
 
 Sarcodina, 197 
 
 Schizogony, 199 
 
 Schizomycetes, 21 
 
 Schizophyceae, 21 
 
 Schizophyta, 21 
 
 Schweinerotlaufbacillus, 194 
 
 Sedgwick's expanded tube for air- 
 examination, 233 
 
 Sedgwick-Tucker method of col- 
 lecting bacteria from air, 233 
 
 Sedimentation test in typhoid 
 fever, 142 
 
 Septicemia, 33 
 
 fowl, 193 
 
 hemorrhagic, 190 
 bacteria of, 192 
 
 mouse, 195 
 
 sputum, micrococcus of, 147 
 Serum, antistreptococcic, 166 ' 
 
 antitoxic, 39 
 
 antituberculous, 122 
 
 blood-, 69 
 
 coagulation of, 72 
 human, preparation of, 74 
 nutrient, preparation of, 72 
 preservation of, in liquid 
 
 state, 74 
 sterilization of, 73 
 
 cytolytic, 40 
 
 precipitin, 40 
 
 test, Wassermann, 42 
 Sewage bacteria, examination for, 
 240 
 
 bacterial treatment of, 243 
 Sewer air, bacteria in, 235 
 Sexual cycle in mosquito, 201 
 Sheep, gangrenous mastitis of, 196 
 Shiga bacillus, 199 
 Side-chain theory of immunity, 
 
 EhrUch's, 36 
 Skin, bacteria on, 257 
 Sleeping sickness, 205, 207 
 Small-pox, 218 
 Smear culture, 78 
 Smegma bacillus, 123 
 Smith's fermentation tube, 81 
 Soap, 264 
 Soda lye, 263 
 Soil bacteria in, 232, 243 
 
 examination of, 232, 243 
 
 fertility, bacteria and, 244 
 Soluble toxins, 31 
 Soor, 222 
 
 Spatula for lifting sections, 57 
 Specimens, drying, 54 
 Spirillum, 103 
 
 aquatilis, 154 
 
 berolinense, 154 
 
 bonhoffii, 154 
 
 cholerae, 148 
 
 allied varieties, 154 
 products, 152 
 
 danubicum, 154 
 
3i8 
 
 INDEX 
 
 Spirillum dunbarii, 154 
 
 milleri, 154 
 
 obermeieri, 217 
 
 of relapsing fever, 217 
 
 of Wernicke, 154 
 
 rubrum, 103 
 
 schuylkilliensis, 154 
 
 weibeli, 154 
 Spirochaeta pallida, 209 
 Spironema pallidum, 209 
 Splenic fever, 105 
 Splenomegaly, tropical, 208 
 Splitting plants, 21 
 Sporangium, 224 
 Spore contents, 25 
 
 formations, 24 
 requisites for, 25 
 Spores, resistance of, 26 
 
 staining, 59 
 
 Klein's method, 60 
 Kiihne's method, 60 
 Weigert's method, 61 
 Sporidium vaccinale, 219 
 Sporocyte, 199 
 Sporogenic bodies, 25 
 Sporogony, 199 
 Sporozoa, 197, 198 
 
 malarial, life cycle of, 199 
 Sporozoites, 201 
 Sputum septicemia, micrococcus 
 
 of, 157 
 Stab culture, 78 
 Stain, alkaline, 49 
 
 Bowhill's orcein, 60 
 
 capsule, 61 
 
 Buerger's method, 61 
 Hiss' method, 61 
 
 carbolthionin, 52 
 
 flagella, with Loflfler's mordant, 
 61 
 
 Frankel's, for tubercle bacilli, 
 
 Giemsa's, 53 
 
 Giinther's, for blood specimens, 
 
 261 
 Hiss' capsule, 52, 61 
 Jenner's, 53 
 
 for malarial organisms, 203 
 Koch's, 50 
 Kiihne's, 51 
 Leishman's, 53 
 
 Stain, Loflfler's, 50 
 for tissues, 59 
 Neisser's, for diphtheria, 52 
 
 for gonococcus, 175 
 NicoUe's, 52 
 removing excess of, 55 
 Romanowsky's, 53 
 Roux's double, 52 
 Welch's capsule, 53 
 Wright's, 53 
 
 for malarial organisms, 204 
 Ziehl-Neelsen, 50 
 Staining, 47 
 
 blood specimens, 57, 261 
 fungi, Unna's method, 61 
 general method, 54 
 Gram's double method, 58 
 
 for tissues, 58 
 malarial organisms, 203 
 of tissue sections, 54, 56, 57 
 solutions, 48 
 compound, 48 
 concentrated, 48 
 formulas of, 49 
 stock, 48 
 special methods, 58 
 spores, 59 
 
 Klein's method, 60 
 Kuhn's method, 60 
 Weigert's method, 61 
 tubercle bacilli in sputum, 117 
 Staphylococcus, 23 
 epidermidis albus, 168 
 pyogenes, 164 
 albus, 168 
 aureus, 166 
 Steam, superheated, 263 
 Stegomyia fasciata, 219 
 Sterilization by filtration, 67 
 fractional, of Tyndall, 65 
 of blood-serum, 73 
 of culture-media, 62, 70 
 of hands, 264 
 of instruments, 45 
 of needles, 79 
 Sterilizer, Arnold's steam, 64 
 
 hot-air, 63 
 Stewart-Slack method of examin- 
 ing milk for bacteria, 252 
 Stock staining solutions, 48 
 Stomach, bacteria in, 259 
 
INDEX 
 
 319 
 
 Streaked surface plating, 79 
 Streptococcus, 23 
 
 acidi lactici, 250 
 
 erysipelatis, 164 
 
 in diphtheria, 133' 
 
 lanceolatus, 157 
 
 puerperaHs, 165 
 
 pyogenes, 164 
 Streptothrices, 227 
 Streptothrix actinomyces, 228 
 
 farcinica, 231 
 
 madurae, 230 
 Stroke culture, 78 
 Structure, 21, 22 
 
 Subcutaneous inoculation of ani- 
 mals, 92 
 Substance sensibilatrice, 40 
 Sugar broths, 71 
 Sulphur dioxid, 264 
 Sulphurous acid gas, 264 
 Suppurative bacteria, ^$ 
 Surra, 204 
 Susceptibihty, S3 
 
 acquired, ss 
 
 inherited, S3 
 
 natural, 37, 
 Swine, erysipelas of, 194 
 Symptomatic anthrax, 187 
 Syphilis, 209 
 
 luetin reaction in, 216 
 
 Wassermann reaction in, 211 
 results, 216 
 Noguchi modification, 214 
 
 Temperature, influence of, on 
 
 life and growth of bacteria, 27 
 Tertian form of malarial protozoa, 
 
 201 
 Test, agglutination, for tubercle ba- 
 cilli, 121 
 in cholera, 152 
 in typhoid fever, 140 
 Pfeiffer's cholera, 153, 154 
 Bordet's cholera, 155 
 Gruber-Widal blood-serum, 140 
 luetin, 216 
 
 Pfeiffer's cholera, 153, 154 
 sedimentation, in typhoid fever, 
 142 
 
 Test, tuberculin, Calmette's oph- 
 thalmic, 121 
 Moro's, 121 
 von Pirquet's, 121 
 
 Wassermann, in syphilis, 211 
 Noguchi's modification, 214 
 results, 216 
 
 Widal, in typhoid fever, 140 
 
 Wisconsin, for bacillus coli in 
 milk, 255 
 Test-tube, 66 
 
 cultures, 78 
 
 potatoes, 68 
 
 Roux's, 68 
 Tetanolysin, 183 
 Tetanospasmin, 182 
 Tetanus, 180 
 
 antitoxin, 183 
 unit for, 183 
 Texas cattle-fever, 208 
 Thermostat for blood-serum, 73 
 Thrush fungus, 222 
 
 parasitic, 222 
 Thrust-culture, 78 
 Tick fever, African, 218 
 Tinea, 225, 226 
 Tissue preparations, 56 
 Torula cerevisiae, 220 
 Toxalbumins, 30, 34 
 Toxemia, 33 
 Toxins, 30, 31, 34 
 
 of diphtheria, 131 
 
 extracellular, 31 
 
 insoluble, 31 
 
 intracellular, 31 
 
 nature of, 34 
 
 soluble, 31 
 Toxoid of diphtheria, 131 
 Toxone of diphtheria, 131 
 Toxophore group, 37 
 Treponema pallidum, 209 
 Trichophyton tonsurans, 224, 225 
 Tricresol, 263 
 
 Tropical splenomegaly, 208 
 Trypanosoma, 204 
 
 brucei, 206 
 
 castellani, 207 
 
 equiperdum, 208 
 
 Evansi, 208 
 
 hominis, 207 
 
 lewisi, 205 
 
320 
 
 INDEX 
 
 Trypanosoma neprevi, 207 
 
 Rougetii, 208 
 
 ugandense gambiense, 207 
 Trypanosomes, 204 
 Trypanosomiasis, human, 207 
 Tsetse fly, 208 
 Tsetse-fly disease, 206 
 Tubercle bacillus, no 
 products of, 120 
 Tuberculin B. E., 120 
 
 Denys' B. F., 120 
 
 Koch's B. E., 120 
 
 R, 120 
 
 reaction, ophthalmic, of Cal- 
 mette, 121 
 
 residuum, 120 
 
 test, Moro's, 121 
 von Pirquet's, 121 
 
 use of, 120 
 Tuberculocidin, 120 
 Tuberculosis, no 
 
 bovine, human tuberculosis and, 
 relation, 119 
 
 in animals, 119 
 Tubes, Esmarch's, 80 
 Tyndall's fractional sterilization, 
 
 65 
 Types, 22 
 
 Typhoid carriers, 139 
 fever, 135 
 
 sedimentation test in, 142 
 Widal reaction in, 140 
 medium, Eisner's, 76 
 for typhoid, 75 
 Typho toxin, 139 
 Typhus fever, 219 
 
 Ultra-microscopic organisms 
 
 218 
 Unna's borax methyl-blue, 51 
 
 method for staining fungi, 61 
 Urethra, bacteria in, 260 
 Urine, bacillus coli in, 102 
 
 bacteria in, 102, 260 
 
 examination of, for tubercle be 
 cilli, 115 
 
 Vaccines, 95 
 
 antistreptococcic, 166 
 
 Vaccines, antityphoid, 139 
 
 bacterial, 95 
 Vaccinia, 218 
 Vagina, bacteria in, 260 
 Variola, 218 
 
 Vibratory movements, 23 
 Vibrio cholerae, 148 
 
 Finkler-Prior, 154 
 
 Metchnikovii, 154 
 
 tyrogenum, 154 
 Vibrion butyrique of Pasteur, 251 
 
 septique, 184 
 Vinegar fermentation, 255 
 Virulence of infection, 32 
 von Pirquet's dermo-tuberculin 
 
 test, 121 
 
 Wassermann reaction in syphilis, 
 211 
 Noguchi modification, 214 
 results, 216 
 Water, artesian well, 236 
 
 bacillus coli in, examination 
 for, 240 
 typhosus in, diagnostic points 
 of, 242 
 bacteria in, method of examina- 
 tion, 238 
 varieties, 238 
 boiUng of, as means of purifying, 
 
 238 
 cholera bacillus in, 152 
 examination of , 232, 235, 238 
 filtered, 236 
 purity of, 235 
 well, 236 
 Weak solutions, 50 
 Weigert's law, 38 
 
 method of staining spores, 61 
 Welch's capsule stain, 53 
 Well water, 236 
 Wernicke's spirillum, 154 
 Wertheim's medium for gonococ- 
 
 cus, 78 
 White mouth, 222 
 Whooping-cough, 161 
 Widal reaction in typhoid fever, 
 
 140 
 Wire cage, 66 
 
INDEX 
 
 321 
 
 Wisconsin test for bacillus coli in 
 
 milk, 255 
 Wolfhugel's counter, 243 
 Woolsorter's disease, 109 
 Wright's chromatin stain for ma- 
 larial organisms, 204 
 
 method of cultivating anaerobic 
 bacteria, 85 
 
 stain, 53 
 Wurzel bacillus, 99 
 
 Yaws, 217 
 
 Yeasts, 220 
 
 examination of, 226 
 pathogenic, 222 
 
 Yellow fever, 219 
 milk, 25 
 
 Ziehl-Neelsen stain, 50 
 Zooglea, 23 
 
 21 
 
SAUNDERS' BOOKS 
 
 Skin, Genito-Urinary, 
 Dentistry, Chemistry, and 
 Eye, Ear, Nose, and Throat 
 
 W. B. SAUNDERS COMPANY 
 
 West Washington Square Philadelphia 
 
 9, Henrietta Street Covent Garden, London 
 
 Our Handsome Complete Catalogue will be Sent on Request 
 
 Stelwag'on on the Skin 
 
 A Treatise on Diseases of the Skin. By Henry W. 
 Stelwagon, M. D., Ph. D., Professor of Dermatology in the 
 Jefferson Medical College, Philadelphia. Octavo of 1309 pages, 
 with 356 text-cuts and ^^ plates. Cloth, $6.50 net. 
 
 Eighth Edition published November, 1916 
 
 The demand for eight editions of this work in such a short period indicates 
 the practical character of the book. In this edition the articles on Frambesia, 
 Oriental Sore, and other tropical diseases have been entirely rewritten. The new 
 subjects include Occupational Dermatoses, Paraflfinoma, Purpura Annularis, Telan- 
 giectodes, Xanthoma Elasticum, and Ulerythema Ophryogenes. George T. Elliot, 
 M. D., Professor of Dermatology, Cornell University, says: "It is a book that I 
 recommend to my class at Cornell, because for conservative judgment, for accurate 
 observation, and for a thorough appreciation of the essential position of dermatol- 
 ogy, I think it holds first place." 
 
 Our books are revised frequently, so that the editions 
 you find here may not be the latest. Write us 
 about any books in which you are interested 
 
SAUXDEJ^S' BOOKS ON 
 
 Schamber^'s Diseases of the 
 Skin and Eruptive Fevers 
 
 Diseases of the Skin and Eruptive Fevers. By Jay 
 
 F. ScHAMBERG, M. D., Profcssor of Dermatology and the In- 
 fectious Eruptive Diseases, Philadelphia Polyclinic. Octavo of 
 585 pages, illustrated. Cloth, $3.25 net. 
 
 THIRD EDITION— published September. 1915 
 
 Dr. Schamberg takes up all diseases of the skin, giving special 
 emphasis to those diseases met most frequently in general practice. 
 The work is particularly full on actinotherapy, rontgenotherapy, and 
 radium, these modern measures being discussed in a separate chap- 
 ter as well as under the various diseases. The exanthemata are 
 considered in a special chapter, diagnosis and treatment being given 
 unusual space. In addition, there are described the usual and the 
 accidental eruptions occurring in such diseases as typhoid, epidemic 
 cerebrospinal meningitis, influenza, malaria, tonsilHtis, etc. This 
 is an important feature. All the new vaccines and serums are con- 
 sidered — their use both in diagnosis and treatment. The many 
 comparative tables of symptoms and the wealth of reHable pre- 
 scriptions make " Schamberg " a most practical work for the gen- 
 eral practitioner as well as for the specialist. 
 
 Johns Hopkins Hospital Bulletin 
 
 "The descriptions of the eruptions are so clear and concise that the appearance of a 
 disease can readily be imagined. The arrangement of diagnosis of many of the diseases is 
 excellent, the points considered being placed opposite one another in parallel rows." 
 
 Asher's Chemistry (b Toxicology for Nurses 
 
 Chemistry and Toxicology for Nurses. By Philip Asher, 
 Ph. G., M. D., Dean and Professor of Chemistry, New Orleans Col- 
 lege of Pharmacy. l2mo of 190 pages. Cloth, ;?i.25 net. 
 
 Dr. Asher's one aim in writing this book was to emphasize throughout the applica- 
 tion of chemical and toxicologic knowledge in the practice of nursing. This he has 
 succeeded in doing. The nurse, both in training-school and in graduate practice, 
 will find it extremely helpful because the subject is made so clear. October, 1914 
 
GENirO-URINARY DISEASES. 
 
 Norris* Gonorrhea in Women 
 
 Gonorrhea in Women. By Charles C. Norris, M. D., 
 Instructor in Gynecology, University of Pennsylvania. With an 
 Introduction by John G. Clark, M. D., Professor of Gynecology, 
 University of Pennsylvania. Large octavo of 520 pages, illus- 
 trated. Cloth, $6.50 net. 
 
 A CLASSIC 
 
 Dr. Norris here presents a work that is destined to take high place among 
 publications on this subject. He has clone his work thoroughly. He has 
 searched the important literature very carefully, over 2300 references being 
 utilized. This, coupled with Dr. Norris' long experience, gives his work the 
 stamp of authority. The chapter on serum and vaccine therapy and organo- 
 therapy is particularly valuable because it expresses the newest advances. 
 Every phase of the subject is considered : History, bacteriology, pathology 
 sociology, prophylaxis, treatment (operative and vci&^xzwLdX)^ gonorrhea during 
 pregnancy, parturition and the puerperiuviy diffuse gonorrheal peritonitis, and 
 all other phases. Further, Dr. Norris considers the rare varieties of gonorrhea 
 occurring in men, women, and children. Published May, 1913 
 
 Coolid^e on Nose and Throat 
 
 Manual of Diseases of the Nose and Throat. By Algernon 
 CooLiDGE, M. D., Professor of laryngology. Harvard Medical 
 School. Octavo of 360 pages, illustrated. Cloth, $1.50 net. 
 
 READY REFERENCE 
 
 This new book furnishes the student and practitioner a guide and ready 
 reference to the important details of examination, diagnosis, and treatment. 
 P^stablished facts are emphasized and unproved statements avoided. Anat- 
 omy and physiology of the different regions are reviewed. 
 
 PubUshed September, 191S 
 
SAUNDERS' BOOKS ON 
 
 Braasch's Pyelography 
 
 Pyelography (Pyelo-Ureterography). By William F. 
 Braasch, M. D., Mayo Clinic, Rochester, Minn. Octavo of 
 323 pages, with 296 pyelograms. Cloth, $5.00 net. 
 
 296 PYELOGRAMS 
 
 This new work is the first comprehensive collection of pyelograms ever 
 issued in book form. The 300 pyelograms included were selected from 
 several thousand made at the Mayo Clinic during the past five years. You get 
 the outlines of normal pelves, those of pathologic conditions, and those of con- 
 genitally abnormal pelves. In addition to the pyelograms, you get a des- 
 criptive text, intrepreting the outlines, pointing out their great value in diagnosis. 
 You get the history of pyelography and the exact technic — selection of 
 medium to be injected, preparation of solution, method of injection, sources 
 of error, etc. The work is a most complete one, beautifully gotten up, and 
 contains much matter of great diagnostic value. Published March, 1915 
 
 Og'den on the Urine TWrd Edition 
 
 Clinical Examination of Urine and Urinary Diag- 
 nosis. A Clinical Guide (or the Use of Practitioners and 
 Students of Medicine and Surgery. By J. Bergen Ogden, 
 M. D., Medical Chemist to the Metropolitan Life In- 
 surance Company, New York. Octavo, 418 pages, 54 text- 
 illustrations, and a number of colored plates. Cloth, $3.00 
 
 net. Published October, 1909 
 
 "We consider this manual to have been well compiled ; and the author's own 
 experience, so clearly stated, renders the volume a useful one both for study 
 and reference." — The Lancet, London. 
 
 Vecki's Sexual Impotence Fifth Edition 
 
 Sexual Impotence. By Victor G. Vecki, M. D. 
 i2mo volume of 400 pages. Cloth, ;g2.25 net. 
 
 "A scientific treatise upon an important and much neglected subject. . . . The 
 treatment of impotence in greneral and of sexual neurasthenia is discriminating 
 and judicious."— /^A«j Hopkins Hospital Bulletin. Published December, 1915 
 
DISEASES OF THE EYE. 
 
 DeSchweinitzV 
 Diseases of the Eye 
 
 The New (8th) Edition 
 
 Diseases of the Eye: A Handbook of Ophthalmic 
 Practice. By G. E. deSchweinitz, M. D., Professor of 
 Ophthalmology in the University of Pennsylvania, Philadelphia, 
 etc. Handsome octavo of 754 pages, 386 text-illustrations, 
 and 7 chromo-lithographic plates. Cloth, $6.00 net. 
 
 Published June, 1916 
 
 WITH 386 TEXT-ILLUSTRATIONS AND 7 COLORED PLATES 
 
 Dr. deSchweinitz's book has long been recognized as a standard authority 
 upon eye diseases, the reputation of its author for accuracy of statement 
 placing it far in the front of works on this subject. For this edition Dr. 
 deSchweinitz has subjected his book to a most thorough revision. Many 
 new subjects have been added, a number in the former edition have been 
 rewritten, and throughout the book reference has been made to vaccine and 
 serum therapy, to the relation of tuberculosis to ocular disease, and to the 
 value of tuberculin as a diagnostic and therapeutic agent. 
 
 The text is fully illustrated with black and white cuts and colored plates, 
 and in every way the book maintains its reputation as an authority. 
 
 Johns Hopkins Hospital Bulletin 
 
 " No single chapter can be selected as the best. They are all the product of a finished 
 authorship and the work of an exceptional ophthalmologist. The work is certainly one of 
 the best on ophthalmology extant, and probably the best by an American author." 
 
 deSchweinitz and Holloway on Pulsating 
 
 £X0phthaIm0S published August, 1908 
 
 Pulsating Exophthalmos. An analysis of sixty-nine cases not pre- 
 viously analyzed. By George E. deSchweinitz, M. D., and Thomas 
 B. Holloway, M. D. Octavo of 125 pages. Cloth, $2.00 net. 
 
 "The book deals very thoroughly with the whole subject, and in it the most com 
 plete account of the disease will be found."— British Medical Journal. 
 
 Jackson's Essentials of Eye Fourth Revised Edition 
 
 Essentials of Refraction and of Diseases of the Eye. By 
 Edward Jackson, A. M., M. D., Emeritus Professor of Diseases of the 
 Eye, Philadelphia Polyclinic. Post-octavo of 261 pages, 82 illustra- 
 tions. Cloth, $1.25 net. In Saunders^ Question-Compend Series. 
 
 "The entire ground is covered, and the points that most need careful elucidation are 
 made clear and ea.sy."— Johns Hopkins Hospital Bulletin. Published AprU, 1906 
 
SAUNDERS' BOOKS OX 
 
 GET A*^^-«I^#v* THE NEW 
 
 THE BEST /\II16riCan STANDARD 
 
 Illustrated Dictionary 
 
 The New (9th) Edition 
 
 The American Illustrated Medical Dictionary. A new 
 
 and complete dictionary of the terms used in Medicine, Surgery, 
 Dentistry, Pharmacy, Chemistry. Veterinary Science, Nursing, 
 and all kindred branches; with over loo new and elaborate 
 tables and many handsome illustrations. By W. A. Newman 
 Borland, M.D. Large octavo of 1 179 pages. Flexible leather, 
 
 I5.OO net; with thumb index, ^5.50 net. Published September, 1917 
 OVER 2000 NEW WORDS IN THIS EDITION 
 
 For this edition the book has been subjected to a thorough revision and 
 entirely reset, adding thousands of important new terms. This work is more 
 than a medical dictionary — it is a Medical Encyclopedia. 
 
 Howard A. Kelly, M.D., 
 
 Professor of Gynecologic Surgery, Johns Hopkins University, Baltimore 
 
 "Dr. Dorland's Dictionary is admirable. It is so well gotten up and of such conve- 
 nient size. No errors have been found in my use of it." 
 
 Pilcher's Practical Cystoscopy 
 
 Practical Cystoscopy. By Paul M. Pilcher, M.D., Con- 
 sulting Surgeon to the Eastern Long Island Hospital. Octavo of 
 504 pages, with 299 illustrations, 29 in colors. Cloth, $6.00 net. 
 
 SECOND EDITION— published November, 1915 
 
 To be properly equipped, you must have at your instant command the 
 information this book gives you. It explains away all difficulty, telling you 
 7v/iy you do not see something when something is there to see, and telling you 
 /io7a to see it. All theory has been uncompromisingly eliminated, devoting 
 every line to practical, needed every-day facts, telling you how and when to 
 use the cystoscope and catheter — telling you in a way to make you hio7C'. 
 
 Bransford Lewis* M. D., S^. Louis University 
 
 " I am very much pleased with Dr. Pilcher's ' Practical Cystoscopy.' I think it is the 
 best in the English language now." 
 
DISEASES OF THE EYE. 
 
 Haab and DeSchweinitz's 
 External Diseases qf the Eye 
 
 (Published February, 1909) 
 
 Atlas and Epitome of External Diseases of the Eye. 
 
 By Dr O. Haab, of Zurich. Edited, with additions, by G. E. 
 deSchweinitz, M. D., Professor of Ophthalmology, University of 
 Pennsylvania. loi colored illustrations and 244 pages of text. 
 Cloth, ;^3.oo net. Third Edition. Saumiefs' Atlases. 
 
 Stokes* The Third Great Plague 
 
 The Third Great Plague: A Discussion of Syphilis for 
 Every=day People. By John H. Stokes, A. B., M. D., Head 
 
 of Section on Dermatology and Syphilology, Division of Med- 
 icine, The Mayo Clinic. i2mo of 204 pages. Cloth, $1.50 
 
 net. Published October, 1917 
 
 American Pocket Dictionary New (loth) Edition 
 
 The American Pocket Medical Dictioxary. Edited by W. A. 
 Newman Borland, M. D. Containing the definition of the principal 
 words used in medicine and kindred sciences. 707 pages. Flexible 
 leather, with gold edges, $1.25 net; with thumb index, $1.50 net. 
 
 " I am struck at once with admiration at the compact size and attractive exterior. 
 I can recommend it to our students without reserve." — James W. Holland, M. D.. 
 Emeritus Professor of Medical Chemistry and Toxicology at the Jeferson Medical College, 
 Philadelphia. Published September, 1917 
 
 Jackson on the Eye Prepanngf-New (3d) Edition 
 
 A Manual of the Diagnosis and Treatment of Diseases of 
 THE Eye. By Edward Jackson, A. M., M. D., Professor of Ophthal- 
 mology, University of Colorado. i2mo of 615 pages, with 184 illus- 
 trations. 
 
SAUNOEKS' BOOKS ON 
 
 Barnhill and Wales' 
 Modern Otology 
 
 A Text-Book of Modern Otology. By John F. Barn- 
 hill, M. D., Professor of Otology, Laryngology, and Rhinology, 
 and Earnest de W. Wales, M. D., Clinical Professor of 
 Otology, Laryngology, and Rhinology, Indiana University School 
 of Medicine, Indianapolis. Octavo of 598 pages, with 314 original 
 illustrations. Cloth, $5.50 net. 
 
 SECOND EDITION 
 
 This work represents the resuUs of personal experience as practitioners and 
 teachers, influenced by the instruction given by such authorities as Sheppard, 
 Dundas Grant, Percy Jakins, Jansen, and Alt, Much space is devoted to 
 prophylaxis, diagnosis, and treatment, botli medical and surgical. There is a 
 special chapter on the bacteriology of ear affections — a feature not to Ijc found 
 in any other work on otology. Great pains have been taken with the illus- 
 trations. A large number represent the best work of Mr. H. F. Aitken. 
 
 Frank AUport. M. D., 
 
 Professor of Otology, Northwestern University, Chicago. 
 
 "I regard it as one of the best books in the English language on this subject. The 
 pictures are especially good, particularly as they are practically all original and not the old 
 reproduced pictures so frequently seen." Published January, 1911 
 
 Davis* Accessory Sinuses 
 
 Development and Anatomy of the Nasal Accessory 
 Sinuses in Man. By Warren B. Davis, M. D., Corinna 
 Borden Keen Research Fellow of the Jefferson Medical College, 
 Philadelphia. Octavo of 172 pages, with 57 original illustra- 
 tions. Published March, 1914 Cloth, $3.50 net. 
 ORIGINAL DISSECTIONS 
 
 This book is based on the study of two hundred and ninety lateral nasal 
 walls, presenting the anatomy and physiology of the nasal accessory sinuses 
 from the sixtieth day of fetal life to advanced maturity. It was necessary for 
 Dr. Davis to develop a ne7v technic by which the accessory sinus areas could 
 be removed en fuasse at the time of postmortem examinations, and still per- 
 mit of reconstruction of the face without marked disfigurement. 
 
GEXITO URINARY AND NOSE, THROAT, Etc. 9 
 
 Greene and Brooks' 
 Genito-Urinary Diseases 
 
 A Text-Book of Genito-Urinary Diseases. By Robert 
 H. Greene, M.D., Professor of Genito-Urinary Surgery at 
 Fordham University; and Harlow Brooks, M. D., Assistant Pro- 
 fessor of Clinical Medicine, Universityand Belleviie Hospital Medi- 
 cal School. Octavo of 666 pages, illustrated. Cloth, $5.50 net. 
 
 FOURTH EDITION— published May. 1917 
 
 This new work covers completely the subject of genito-urinary diseases, 
 presenting both the medical and surgical sides. Kidney diseases are very elabo- 
 rately detailed. 
 
 New York Medical Journal 
 
 " As .a whole the book is one of the most satisfactory and useful works on genito- 
 urinary diseases now extant, and will undoubtedly be popular among practitioners and 
 
 students." 
 
 Gleason on Nose, Tliroat, 
 and Ear 
 
 A Manual of Diseases of the Nose, Throat, and Ear. By 
 
 E. Baldwin Gleason, M. D., LL. D., Professor of Otology, 
 Medico-Chirurgical College, Graduate School of Medicine, Uni- 
 versity of Pennsylvania, Philadelphia. i2mo of 590 pages, pro- 
 fusely illustrated. Cloth, $2.75 net. Published October, 1914 
 
 THIRD EDITION 
 
 Methods of treatment have been simplified as much as possible, so that in 
 most instances only those methods, drugs, and operations have been advised 
 which have proved essential. A feature consists of the collection of formulas. 
 
 American Journal of the Medical Sciences 
 
 " For the practitioner who wishes a reliable guide in laryns^ology and otology there ar 
 few books which can be more heartily commended." 
 
 Wilcox on Genito-Urinary and Venereal Dis- 
 eases Second Edition, published January. 1909 
 
 Essentials of Genito-Urtnary and Venereal Diseases. By 
 St.arling S. Wilcox, M. D., Lecturer on Genito-Urinary Diseases and 
 Syphilology, Starling-Ohio Medical College, Columbus, Ohio. i2mo of 
 321 pages, illustrated. Cloth, $1.25 net. In Saunders' Quest ion-Com- 
 pends. 
 
SAUNDERS' BOOKS ON 
 
 Head's Modern Dentistry 
 
 Modern Dentistry. By Joseph Head, M. D., D.D.S., Den- 
 tist to the Jefferson Hospital, Philadelphia. Octavo of 374 
 pages, with 309 illustrations. Cloth, $5.00 net. 
 
 Published December, 1917 
 
 Dr. Head's book is a complete and up-to-date text-book on dentistry. 
 It gives you the principles upon which successful work must be based — 
 the technic in full, and the results of original experiments, with formulae, 
 instruments, and methods. It brings out clearly the various factors which 
 influence the diagnosis, and carefully details the methods of treatment. 
 The subject of vaccines is gone into very fully, giving you preparation and 
 use of autogenous, stock, and special vaccines. Particularly useful are 
 the sections on mouth hygiene, local anesthesia by novocain, electrolysis, 
 tooth discoloration, care of children's teeth and gums, orthodontia for 
 the general practitioner of dentistr}^, cement, .v-ray study, and the use of 
 emetin. Over three hundred original. illustrations show the student just 
 how the procedures are to be carried out. 
 
 Kyle's Nose and Throat 
 
 Diseases of the Nose and Throat. By D. Braden Kyle, 
 M.D., formerly Professor of Laryngology in the Jefferson Medical 
 College, Philadelphia; Consulting Laryngologist, Rhinologist, 
 and Otologist, St. Agnes' Hospital. Octavo, 856 pages; with 
 272 illustrations and 27 lithographic plates in colors. Cloth, 
 
 ;^ 4. 50 net. Published November, 1914 
 
 FIFTH EDITION 
 
 This work has now reached its fifth edition. With the practical purpose 
 of the book in mind, extended consideration has been given to treatment, each 
 disease being considered in full, and definite courses being laid down to 
 meet special conditions and symjitoms. 
 
 Pennsylvania Medical Journal 
 
 " Dr. Kyle's crisp, terse diction has enabled the inclusion of all needful nose and throat 
 knowledge in this book. The practical man, be he special or general, will not search in 
 vain for anything he needs." 
 
CHEMISTRY AMD DENTISrii 
 
 Holland's 
 Chemistry and Toxicology 
 
 A Text-Book of Medical Chemistry and Toxicology, 
 
 By James W. Holland, M. D., Emeritus Professor of Medical 
 Chemistry and Toxicology , Jefferson Medical College, Phila- 
 delphia. Octavo, 678 pages, illustrated. Cloth, ^3.00 net. 
 
 FOURTH EDITION— published April. 1915 
 
 Dr. Holland's work is an entirely new one, and is based on his thirty-five 
 years' practical experience in teaching chemistry and medicine. Recognizing 
 that to understand physiologic chemistry students must first be informed upon 
 points not referred to in most medical text-books, the author has included in his 
 work the latest views of equilibrium of equations, mass-action, cryoscopy, os- 
 motic pressure, etc. Much space is given to toxicology. 
 
 American Medicine 
 
 " Its statements are clear and terse ; its illustrations well chosen; its development lojfi- 
 cal, systematic, and comparatively easy to follow. . . . We heartily commend the work." 
 
 Ivy's Applied Anatomy and Oral Surgery 
 
 Applied Anatomy and Oral Surgery for Dental Students. 
 By Robert H. Ivy, M. D., D. D. S., Assistant Oral Surgeon to the 
 Philadelphia General Hospital. 1 2mo of 290 pages, illustrated. Cloth, 
 $1.75 net. Second Edition published July, 1917 
 
 This work is just what dental students have long wanted — a concise, practical work 
 on applied anatomy and oral surgery, written with their needs solely in mind. No 
 one could be better fitted for this task than Dr. Ivy, who is a graduate in both den- 
 tistry and medicine. The text is well illustrated with pictures that you will find ex- 
 tremely helpful. 
 
 "I am delighted with this compact little treatise. It seems to me just to fill the 
 bill."— H. P. KuHN, M. D., Western Dental College, Kansas City. 
 
 Oertel on Bri^ht's Disease 
 
 The Anatomic Histological Processes of Bright's Disease. By 
 HoRST Oertel, M. D., Director of the Russell Sage Institute of Path- 
 ology, New York, Octavo of 227 pages, with 44 illustrations and 6 
 colored plates. Cloth, jJIS-OO net. 
 
 These lectures deal with the anatomic histological processes of Bright's disease, and 
 in a somewhat different way from the usual manner. Everywhere relations are em- 
 phasized and an endeavor made to reconstruct the whole as a unit of interwoven 
 processes. Published December, 1910 
 
 " Dr. Oertel gives a clear and intelligent idea of nephritis as a continuous process. 
 " We can strongly recommend this book as thoughtful, scientific, and suggestive." — 
 The Lancet, London. 
 
SAU.XDEKS' BOOK'S ON 
 
 Goepp's Dental State Boards 
 
 E>ental State Board Questions and Answers. By R. 
 
 Max Goepp, M. ])., Professor of Clinical Medicine at the Phila- 
 delphia Polyclinic. Octavo of 428 pages. Cloth, ;^3. 00 net. 
 
 SECOND EDITION 
 
 This new work is along the same practical lines as Dr. Goepp's successful 
 work on Medical State Boards. The questions included have been gathered 
 from reliable sources, and embrace all those likely to be asked in any State 
 Board examination in any State. They have been arranged and classified in 
 a way that makes for a rapid resume of every branch of dental ])ractice. and 
 the answers are couched in language unusually explicit — concise, definite, 
 accurate. Published February, 1916 
 
 McConnell's Pathology and Bacteriology Dent&l 
 
 General Pathology and Bacteriology" for Dental 
 Students. By Guthrie McConnell, M. D., Assistant 
 Surgeon, Medical Reserve Corps, U. S. N. 121110 of 314 
 
 pages, illustrated. Second Edition published January, 1918 
 
 This work was written expressly for dentists and denial students, em- 
 phasizing throughout the application of pathology and bacteriology in 
 dental study and practice. There are chapters on disorders of metab- 
 olism and circulation ; retrogressive processes, cell division, inflam- 
 mation and regeneration, granulomas, progressive processes, tumors, 
 special mouth pathology, sterilization and disinfection, bacteriologic 
 methods, specific micro-organisms, infection and immunity, and labora- 
 tory technic. 
 
FA'E, EAR, NOSE, AXD THROAT. 13 
 
 Bass and Johns' Alveolodental Pyorrhea 
 
 Alvkolodental Pyorrhea. By Charles C. Bass, M.D., Professor 
 of Experimental Medicine, and Foster M. Johns, M. D., Instructor in 
 the Laboratories of Clinical Medicine, Tulane Medical College. Octavo 
 of 168 pages, illustrated. Cloth, $2.50 net. Published June, 1915 
 
 This work discusses alveolodental pyorrhea from the viewpoint of infeqtion by the 
 Endamoeba buccalis in a simple, concise way, in the light of recent information. 
 
 Gleason's Nose and Throat Fourth Edition. Revised 
 
 Essentials of Diseases of the Nose and Throat. By E. B. 
 Gleason, S.B., M.D., Clinical Professor of Otology, Medico-Chirurgical 
 College, Graduate School of Medicine, University of Pennsylvania, 
 Post-octavo, 241 pages, 112 illustrations. Cloth, $1.25 net. In 
 Saunders^ Question-Compend Series. Published October, 1914 
 
 "The careful description which is given of the various procedures would be sufficient 
 to enable most people of average intelligence and of slight anatomical knowledge to 
 make a very good attempt at laryngoscopy."— JAe Lancet, London. 
 
 Grant on the Face, Mouth, and Jaws 
 
 A Text-Book of the Surgical Principles and Surgical Dis- 
 eases OF the Face, Mouth, and Jaws. For Dental Students. By 
 H. Horace Grant, A. M., M. D., Professor of Surgery and of Clinical 
 Surgery, Hospital College of Medicine, Louisville. Octavo of 231 pages, 
 with 68 illustrations. Cloth, $2.50 net. Published September, 1911 
 
 Preiswerk and Warren's Dentistry 
 
 Atlas and Epitome of Dentistry. By Prof. G. Preiswerk, of 
 Basil. Edited, with additions, by George W. Warren, D. D. S., Pro- 
 fessor of Operative Dentistry, Pennsylvania College of Dental Surgery, 
 Philadelphia. With 44 lithographic plates, 152 text-cuts, and 343 pages 
 of text. Clotli, $3.50 net. Saunders' Hand-Atlases. August, 1906 
 
 Grunwald and Grayson on the Larynx 
 
 Atlas and Epitome of Diseases of the Larynx. By Dr. L. 
 GRtJNWALD, of Munich. Edited, with additions, by Charles P. 
 Grayson, M. D., University of Pennsylvania. With 107 colored figures 
 on 44 plates, 25 text-cuts, and 103 pages of text. Cloth, 1^2.50 net. In 
 Saunders* Hand-Atlas Series. Published 1898 
 
 Mracek and Stelwagon's Atlas of Skin 1'^';^;^ 
 
 Atlas and Epitome of Diseases of the Skin. By Prof. Dr. 
 Franz Mracek, of Vienna. Edited, with additions, by Henry W. 
 Stelwagon, M. D., Jefferson Medical College. With 77 colored 
 plates, 50 half-tone illustrations, and 280 pages of text. Cloth, $4.00 
 net. In Saunders' Hand-Atlas Series. Published July, 1903 
 
14 SAUNDEXS'- BOOKS ON 
 
 Theobald's 
 Prevalent Diseases of the Eye 
 
 Prevalent Diseases of the Eye. By Samuel Theobald, 
 M. D., Clinical Professor of Ophthalmology and Otology, Johns 
 Hopkins University. Octavo of 550 pages, with 219 text-illustra- 
 tions and 10 plates. Cloth, $4.50 net. Published July, 1906 
 
 Chas. A. Oliver, M. D.. 
 
 Cli7iical Professor of Ophthalmology, Woman's Medical College, Fhila. 
 " I feel I can conscientiously recommend it, not only to the general physician and 
 medical student, but also to the experienced ophthalmologist." 
 
 Wells* Chemical Patholo^ 
 
 Chemical Pathology. By H. Gideon Wells, Ph.D., 
 M. D., Professor of Pathology in the University of Chicago. 
 Octavo of 616 pages. Cloth, $3.25 net. Second Edition 
 
 Published March, 1914 
 Wm. H. Welch, M.D.,y<?/««^ Hopkms University. 
 
 " The work fills a real need in the English literature of a very important subject, and I 
 shall be glad to recommend it to my students." 
 
 Stelwa|»on's Essentials of Skin seventh Edition 
 
 Essentials of Diseases of the Skin. By Henry W. Stelwagox, 
 M. D., Ph. D., Professor of Dermatology in the Jefferson Medical 
 College, Philadelphia. Post-octavo of 292 pages, with 72 text-illustra- 
 tions and 8 plates. Cloth, $1.25 net. In Saunders' Question-Compend 
 Series. Published August, 1909 
 
 " In line with our present knowledge of diseases of the skin. . . . Continues to main- 
 tain the high standard of excellence for which these question cornpends have beea 
 noted." — The Medical News. 
 
Saund^^iCQ C 
 
 nrnT^w^rii 
 
 illu^ 
 
 DATE DUE SLIP 
 
 UOTVERSITY OF CALIFORNIA MEDICAL SCHOOL LIBRARY 
 
 THIS BOOK IS DUE ON THE LAST DATE 
 STAMPED BELOW 
 
 stion- 
 d best 
 
 rec 
 wit 
 
 -'■-/- - 
 
 Sta 
 
 
 cop 
 
 liioS 
 
 anc 
 
 
 se\ 
 
 
 
 ^f^5 
 
 
 ?'# 18 1936 
 
 
 ^^ 1339 
 
 
 FEB 2 9 1940 
 
 
 MAY17I5C 
 
 
 NOV 1 4 1940 
 
 
 iAR 9- t943 
 
 
 950 
 
 now 
 rature 
 Jnited 
 se in- 
 i,000 
 evised 
 their 
 
 SIDNEY 
 
 IS. By 
 
 s. By 
 
 Law- 
 
 Vi^VlilTMER, 
 
 JTICS. 
 
 iENRY 
 
 , M.D. 
 
 3>/i-10,'34 
 
Saunders' Compends 
 
 ESSENTIALS OF GYNECOLCXiY. 8th ed. With 57 illustrations. 
 By Edwin B. Cragin, M. D. Revised by F. S. Mathews, M. D. 
 
 .-.>^^~^'^'=^^-'*^ OF THE SKIN. 7th edition. 
 
 ;i^« Ball I M.V. 
 
 ESSENTj 
 Soil! 
 
 3577;? 
 
 .(ARY