LIBRARV 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA 
 
 GIFTT OK 
 
 f\ 
 
 u 
 
l>e University of 
 
 KOTXDKI) 1IY JOHN I). ROCKEFELLER. 
 
 t COMPMUTIVE m EXPERIMENTtL STODV OF OiCILLI 
 PRODUCING BED PICMEHT. 
 
 A DISSERTATION 
 
 SUBMITTED TO THE FACULTIES OF THE GRADUATE SCHOOLS OF ARTS, 
 
 LITERATURE, AND SCIENCE, IN CANDIDACY FOR THE 
 
 DEGREE OF DOCTOR OF PHILOSOPHY 
 
 DEPARTMENT OF BACTERIOLOGY 
 
 BY 
 
 MARY HEFFERAN. 
 
 JENA, 
 
 GUSTAV FISCHER. 
 1904. 
 
H4 
 
 
Contents. 
 
 Page 
 
 A. Introductory 1 
 
 B. His tori cal and Descriptive 3 
 
 C. Comparative and Experimental Stud y (Tables I 
 
 -VIII) 20 
 
 I. Color determination of bacterial pigment 20 
 
 II. Variability in the Prodigiosus group 23 
 
 1. Introductory "23 
 
 2. Discontinuous variation or mutation 24 
 
 3. Range of normal variation 27 
 
 a) Growth and pigment on ordinary culture media . . 27 
 
 b) Growth and pigment on special solid media ... 29 
 
 c) Growth and pigment in non-proteid media .... 35 
 
 d) The effect of light upon pigment production ... 40 
 
 4. Summary 42 
 
 D. Notes on Groups of Red Chromogenic Bacilli . . 43 
 
 I. The Prodigiosus group 44 
 
 II. The Lactis erythrogenes group 44 
 
 III. The Rubricus group 44 
 
 Table IX 46 
 
 Table X 48 
 
 Bibliography 45 
 
 Reference List of Other Red Chromogenic Bacteria .... 54 
 
 1 si non 
 
A. Introductory. 
 
 The mechanical difficulties of observing structures so minute 
 as bacteria have led to the accumulation of much differential detail, 
 and to an insistence on all points of unlikeness in physiological 
 characters or cultural reactions. Further, the lack of uniform 
 methods and standards of comparison has tended to produce an 
 overwhelming multiplicity of inadequate species-descriptions, in 
 which any slight variation from existing descriptions, e. g. as regards 
 formation of colonies on gelatin, has been erected into a character 
 of specific importance. But with the publication of Marshall 
 Ward's series of studies on Thames bacteria, of F u 1 1 e r and John- 
 ston's work on the bacteria of the Ohio River, and of Jordan's 
 paper on some 600 germs found in the Mississippi River, a check 
 has been put to indiscriminate multiplication of bacterial "species". 
 Recently , again , the demonstration of linking intermediate para- 
 typhoid and enteritidis forms in the colon-typhosus group, and of 
 the marked range of individual variation occurring in other orga- 
 nisms, has rendered especially important the questions of varia- 
 bility and of the actual lines between "species", "varieties", and 
 "races". 
 
 The chromogenic bacteria afford, from the fact of their pig- 
 mentation, a particularly suitable field for observation; and the 
 non-parasitic nature of the special group here considered is another 
 factor favorable for comparative and for variation study. The 
 warping effect of parasitic life upon the physiological and morpho- 
 logical character of organisms is well known, and more characte- 
 ristic results are to be anticipated from the study of variation 
 in a group of saprophytic organisms than in a group of pathogenic 
 organisms. 
 
 The agreement, among a number of bacteria, in a characte- 
 ristic so marked as is pigment production, might conceivably place 
 a series of red or yellow chromogenic germs in a category by 
 themselves, and raise the question whether this agreement in color 
 production be paralleled by agreement in biochemical and other 
 features, and whether the pigmentation be a fixed, a variable, or 
 a vital character of the organisms. So far, however, attention has 
 not been directed to a series of chromogenic germs, with the 
 exception of the comparative work done byThumm, byRuzi^ka, 
 and by Jordan on strains of B. pyocyaneus, and of the chemical 
 studies on bacterial pigments in general, referred to below. The 
 best known of the red saprophytes, B. prodigiosus, has been 
 
 1 
 
quite fully discussed since its first descriptions; but no more than 
 two or three of its nearest relatives have at any time been in- 
 cluded with it in the study. 
 
 The parallel treatment attempted in this paper possesses certain 
 points of value; but comparison of a relatively large] number of 
 organisms has its obvious disadvantages as well as its advantages. 
 The number brought under discussion is plainly too great to per- 
 mit, in limited time and space, of extending the work on each 
 germ into detail, or of carrying out all possible tests, chemical, 
 spectroscopic and physiological. But, on the other hand, the com- 
 parison of so many red chromogenic bacteria must throw some 
 light on general features of relationship and variability which are 
 apt to be obscured or lost sight of when attention is concentrated 
 on a single organism or on a small group. 
 
 With these considerations in mind, I have attempted compara- 
 tive study of the following series of forty cultures of red chromo> 
 genie bacilli. A few of these, often referred to in bacteriological 
 literature, have been more or less completely studied as individuals, 
 e. g. B. prodigiosus, B. kiliensis, B. lactis erythro- 
 genes; but the majority, though frequently mentioned, have 
 received only the most cursory descriptions. I have therefore 
 prefixed to my comparative notes a brief description of each 
 "species" here discussed. A list of red chromogenic bacilli not 
 obtainable for study will be found at the close of the paper, where 
 are also tabulated the data regarding my series. 
 
 As an aid in determining the specificity of some members of 
 the series, I obtained from various laboratories eight cultures of 
 B. prodigiosus; the range of variability thus demonstrated for 
 that species and the other parallels or differences between the 
 allied cultures have suggested my closing note on grouping and 
 differentiation. 
 
 Red chromogenic bacilli described in this paper. 
 B. prodigiosus (Ehrenberg) I VIII 
 
 I, from University of Chicago. 
 
 II, from Rush Medical College, Chicago, 1902. 
 
 III, from Board of Health, Chicago, 1902. 
 
 IV, from University of Minnesota, 1903, 
 
 V, from University of Minnesota, 1903. 
 
 VI, from Yale University, 1903. 
 
 VII, from Ontario, Board of Health, 1903. 
 
 VIII, from University of Michigan, 1903. 
 
 'iber 
 
 indie us (Koch) I, from KraTs Laboratorium, 1900. 
 
 i, II O AJMAUMMMIIUIlj -LiTWS. 
 
 II, from Rush Medical College, Chicago, 1902; 
 obtained by them from Parke, Davis & Com- 
 pany, Detroit, 1899, obtained by the latter from 
 the University of Michigan (?) several years before. 
 
 B. ruber plymouthensis (Fiacher) I, from KraTs Laboratorium, 1899. 
 * * II, (B. No. 18), from air at Cold Spring 
 
 Harbor, L. I., I'.iu). 
 III, (II. No. ID), from air at Cold Spring 
 
 HarUr. 
 B. ki liens is (Breunije) from Rush Medical College, Chicago, 1902; obtained by 
 
 them from Parke, Davis & Company, 1&9. 
 B. ruber balticus (Breunig, Kruse) from Krai'* Laboratorium, 1900. 
 
s B^ 
 */&. 
 
 B. miniaceus (Zimmermann) I, from Krals Laboratorium, 1901 
 II, from Hoagland Laboratory, Brooklyn, 1899. 
 
 HI, from Rush Medical College, 1902; obtained 
 
 by them from Hoagland Laboratory, Brooklyn. 
 ^Y. rutilus (n. sp.) from the water of the Mississippi River, 1899. 
 "K amyloruber (n. sp.) from the water of the Mississippi River, 1901. 
 B. fuchsinus (Boekhout and de Vries) from Krai's Laooratorium, 19QO. 
 B. ruber (Miquel) from Krai's Laboratorium, 1900. 
 f^B. rubricus (n. sp.) from the water of the Mississippi River, 1901. 
 ^B. rufus (n. sp.) from the water of the Mississippi River, 1901. 
 B. ruber (Zimmermann) from Krai's Laboratorium, 1900. 
 B. havaniensis (Sternberg) from University of Chicago. 
 yt&. 1 act is ery thro genes (Hueppe) 1, from Krai's Laboratorium, 1900. 
 II, from the Mississippi River, 1901. 
 
 B. rubefaciens (Zimmermann) from Krai's Laboratorinm, 1900. 
 B. lactorubefaciens (Gruber) from Gruber, 1902. 
 B. ru til esc ens (n. sp.) from the water of the Mississippi River, 1901. 
 B. my co ides roseus (Scholl) from Krai's Laboratorium, 1900. 
 /BC mycoides corallinus (n. sp.) from the water of the Mississippi River, 1899. 
 B. latericeus (Adametz) from Krai's Laboratorium, 1900, 1903. 
 B. rubropertinctus (Grassberger) from Krals Laboratorium, 1902; not 
 
 named by Grassberger. 
 
 B. rosaceus metalloides (Tataroff) from Krai's Laboratorium, 1900 1 ). 
 B. mesentericus ruber (Globig) I IV 
 
 I, from Krai's Laboratorium, 1900, 1903. 
 
 II, from the water of the Mississippi River, 
 
 1901. 
 
 /<f III, IV, from the water of the Mississippi 
 
 River, 1901. 
 
 B. Historical and Descriptive. 
 
 B. prodigiosus is usually taken as a type of red pigment 
 producing bacteria, and is said to be the earliest chromogenic 
 bacterium known. Considering, however, the frequency with which 
 there are found in air different varieties of red pigment germs 
 not identical with, but much like Prodigiosus, the history usu- 
 ally connected with the name of Prodigiosus probably extends 
 to many varieties of this type. 
 
 The frequency with which certain of the red chromogenic bac- 
 teria appear upon food-stuffs has been a matter of observation 
 for centuries. L u c i a n , in one of his dialogues (2 d century A. D.), 
 makes Pythagoras give, as reason for forbidding his disciples to 
 eat beans, the fact that white cooked beans, if placed in the moon- 
 light, change into blood. Since the forbidding of beans as food is 
 common to various sects of ancient times, e. g. to the Egyptian 
 priests and to the Zoroastrians , from which latter Pythagoras 
 doubtless obtained the notion, the recognition of this pigmentation 
 appears to be of extreme antiquity. In the year 332 B. C. the so- 
 called "blood-miracle" was of service to Alexander the Great 
 in the conquest of Tyre. The bread of his besieging army was dis- 
 covered to be reddened when broken; but the priests quieted the 
 terrified soldiery by interpreting the omen to mean, that as the 
 "blood" was inside the bread, a bloody fate would fall upon those 
 inside, not outside, the city. For the story see Curtius Rufus, 
 Hist. Alexandri, chap. 2, bk. 4. 
 
 1) Previously described by the writer, cf. An unusual bacterial grouping. 
 (Centralbl. f. Bakt. Bd. VIII. 1902. p. 690.) 
 
The phenomenon of the "bleeding host", so often regarded as 
 a miracle in the Middle Ages, was due to a similar cause. The 
 composition of the sacramental bread, rich in starch and poor in 
 acid, was well adapted to the rapid growth of Schizomycetes ; but 
 the popular explanation of the phenomenon was that the host had 
 been stabbed by unbelieving Jews. The number of executions 
 and murders due to this belief was so great that Scheurlen, in 
 alluding to it, remarks that "dieser Saprophyt mehr Menschen um- 
 gebracht hat als mancher pathogene Bacillus". 
 
 Three nineteenth century appearances of this "blood miracle"' 
 as epidemic in a town or neighborhood are of interest. In the 
 year 1819, at Legnaro, near Padua, Italy, the whole district was 
 set in commotion by the appearance of red spots upon food. An 
 investigation was undertaken by physicians and professors of the 
 University of Padua, the fungus nature of the growth was dis- 
 covered, and two separate names given to it. B i z i o (23) called the 
 organism Serratia marcescens, the Serratia in compliment 
 to the savant who first propelled a boat by steam on the Arno. 
 His generic description is of interest: - -"Funguli acaules, senri- 
 sphaerica, capsulis contortis. Serratia marcescens. Vesicula tenuis- 
 sima, latice primo roseo, dehinc rubro repleta." Bizio reprinted 
 his paper of 1823 in volume I of his Opuscoli chimico-fisico, 
 1827, and several times later asserted his claim to priority in the 
 investigation of B. prodigies us. Meanwhile, the same epidemic 
 of Legnaro had been reported by Sette (25), and the name of 
 Zoogalactina immetropa given to the organism. More than 
 twenty years later, in January 1844, there appeared in the Jour- 
 nal de Pharmacie a report by various members of the French 
 Academy of Sciences, who had been commissioned to investigate 
 a reddening of the munition bread which was exciting among the 
 French soldiery much the same agitation as had prevailed among 
 the troops of Alexander. This report, and the treatment of the 
 phenomenon as new, brought out a letter from Bizio (24), emphasi- 
 zing his work of twenty-four years earlier, and giving the reference 
 to it. However, the next noteworthy epidemic of the sort in 
 Berlin in 1848, investigated by Ehrenberg (26), has not only 
 fixed upon the organism the name Prodigiosus then given to 
 it, but has connected the name of the German scholar with its 
 discovery. 
 
 Since Ehrenberg 's monograph many investigators have dealt 
 with the biological characteristics and the pigment of B. prodi- 
 giosus. A differentiation among the red germs was introduced much 
 later; thus, B. ruber indicus was first described in 1884, 
 B. ruber plymouthensis by Fischer in 1887, B. mesenteri- 
 cns ruber (Globig) in 1888, and B. lactis erythrogenes 
 (Hueppe) in 1889, etc. 
 
 B. prodigiosus (Ehrenberg). 
 
 This most common of all the pigment forms has been so com- 
 pletely described within the last few years that I can add little 
 
except in confirmation or contradiction of the results already ob- 
 tained. The following description of my culture B. prodi- 
 g i o s u s I , believed to be typical, will be used as a standard for 
 comparison of a series of similar forms. 
 
 Morph ology. 
 
 Ehrenberg described his organism as a monad. Erd- 
 mann (28), when it appeared in the cholera epidemic of 1866, 
 called it a bacillus. Schroeter (29) 1872) named it Bac- 
 terium prodigiosum, meaning by his use of the term Bac- 
 terium that it was non-motile. It was first called a Micrococcus 
 by Cohn (30) in 1872, and was known as such until Schotte- 
 lius (35) in 1887 described it as a motile rodlet. Wasserzug (37) 
 (1888) thought he could produce the coccus or the bacillus form 
 at will by growth on alkaline or acid agar. In 1896 Scheur- 
 1 e n (43) made a careful description of the morphology of B. p r o - 
 digiosus; a two day culture in neutral bouillon showed a rod 
 1,5 2 times as long as broad, with rounded ends. On the long 
 side were 24 flagella. On a two-day potato culture, the rods 
 were smaller, ellipsoid, and capsulated. Scheurlen ascribed this 
 variation to the production of unstable alkali (ammonia) by the 
 organism itself. The same thing was true for alkaline media. 
 Finally, Migula (10) (1900) adds, that the bacillus is 0,5 ji 
 broad and from 0,5 1,0 JLI long, sometimes occurring in chains of 
 26 bacilli. Motility increases and the rodlike form becomes more 
 marked in slightly acid media. Flagella are peritrichial , but vary 
 in number and length. 
 
 Cultural features 1 ). 
 
 Gelatin. Investigators have not differed as to the growth 
 of B. prodigiosus on gelatin and agar. On a gelatin plate 
 the growth takes place quickly ; after twentj -four hours at 20 25 C, 
 the deep colonies appear round, sharply contoured, granular and 
 gray. The surface colonies are thinner and more granular, white, 
 and round or slightly irregular on the edges. On the following 
 day the gelatin is completely liquefied, a red color appears, and 
 later the whole liquid becomes red and cloudy. 
 
 In a vigorous gelatin stab culture a deep funnel of lique- 
 faction appears in 24 hours. Pigment appears in 48 hours, and the 
 gelatin is rapidly liquefied to the bottom of the tube and colored 
 red throughout. Usually no pellicle is formed. The rapidity of 
 liquefaction as well as of pigment production varies according to 
 the quality of the medium and the degree of vigor of the cultures. 
 
 Agar. The character of the colonies on an agar plate is 
 quite uniform. In 24 hours the colonies appear in the depths, 
 ellipsoid, granular, and reddish. On reaching the surface they 
 spread out round, thinner, and granular, becoming bright red. The 
 color appears first in the center, and under low power the edges 
 are thin, transparent, and finely granular. The diameter reaches 
 37 mm in five days. 
 
 1) Unless otherwise specified, observations were made at room temperature, 
 18-24 C. 
 
On agar slant the growth appears first as a white smooth moist 
 layer, in 24 hours becoming bright red. In three or four days a 
 green fuchsin-like luster appears on the surface. Old cultures grow 
 darker in color (cf. table in section on pigment). 
 
 Potato. This was the culture medium used by the early 
 investigators. The growth and pigment production are here most 
 beautiful, particularly if the potato is fresh and slightly acid. A 
 white line appears in twelve to eighteen hours, which rapidly turns 
 red. The growth is luxuriant and the surface takes on a green 
 metallic luster in a few days, while the red color spreads over the 
 potato by means of the film of moisture. If the potato is dry, 
 growth and pigmentation are limited to the needle track, and the 
 superficial green appears as an abundant, dull, granular layer. 
 
 Blood serum. The growth is like that upon agar, but 
 slighter. The medium later undergoes liquefaction. 
 
 Bouillon. Ordinary neutral bouillon becomes cloudy in 12 
 to 18 hours. Later a ring of red color appears at the surface and 
 a flocculent red and white sediment accumulates. The surface 
 sometimes has a slight red pellicle and the whole liquid may be 
 tinged red. 
 
 Milk. In milk the red color appears at the surface, the pig- 
 ment, according to Fliigge (3) and Migula (10), adhering to 
 the fat droplets. A soft solid coagulum^s formed in 48 hours by 
 the simultaneous formation of "Milchsaure und Labferment" 
 (Gorini (41)). In ten days the coagulum shrinks to half its size, 
 leaving a clear watery serum. Little or no peptonization takes 
 place. 
 
 Gas production. The question of the production of gas 
 in sugar solutions by B. prodigiosus has occasioned some dis- 
 cussion. Liborius (34) (1886) described gas development by 
 B. prodigiosus in dextrose gelatine. Schottelius (35) (1887) 
 stated that this organism possessed in a marked degree the power 
 of converting sugar solution into alcohol and C0 2 , a statement 
 which has been embodied in Fraenkel's text book (4). S c h e u r - 
 len, however, disagrees with this conclusion of Schottelius. 
 He found that, in a peptone solution to which 2 % sugar had 
 been added, a gas bubble appeared upon inoculation with B. pro- 
 digiosus, did not increase, and, because of its absorption by 
 NaOH, was proved to be C0 2 ; but he believed this to be the 
 result of the action of succinic acid (which he had shown to be 
 a product of B. prodigiosus in potato culture) upon the sodium 
 carbonate used to neutralize the bouillon. When he tried a sugar 
 peptone bouillon neutralized by sodium-phosphate, or one to which 
 no alkali had been added, or an asparagin-sulphate-phosphate sugar 
 solution, he obtained no gas bubble. The bubble appeared, however, 
 when B. prodigiosus was grown in any medium which had 
 been neutralized by Na 2 C0 8 , even when the medium contained no 
 sugar. He also obtained gas without the presence of B. pro- 
 digiosus merely by the addition of a little succinic acid to the 
 medium. Ritter (47) (1900) confirms Scheurlen, and says 
 
that the gas of Liborius and Schottelius was only a chemi- 
 cal product of the action of succinic acid, which B. prodigiosus 
 forms from sugar upon Na 2 C0 3 . 
 
 My results differ from those of Scheurlen and of Ritter. 
 In standard bouillon, freed from muscle sugar by Theobald 
 Smith's method, neutralized by NaOH instead of by Na. 2 C0 3 , 
 and then having added to it iy 2 / dextrose, B. prodigiosus 
 I produced at the end of a week a bubble of gas in the fermen- 
 tation tube. Contrary to Scheurlen's observation, this did not 
 remain stationary but increased daily. 
 
 1) 7th day 4 mm 2) 7th day bubble 
 
 8th 7 8th 12 mm 
 
 10th 5 10th 19 
 
 12th 5 llth 
 
 17th 5 
 
 19th 
 
 31 mm 34,5 % 
 
 26 mm 34,5 % 
 
 All of the gas was absorbed by NaOH, showing that the gas 
 formed was C0 2 . Fermentation of the carbohydrate must have 
 taken place, for in this case no sodium carbonate had been added 
 to the medium, from which succinic acid could set C0 2 free. The 
 end reaction of the medium was acid to litmus. 
 
 In lactose and sucrose bouillon no gas was produced, nor did 
 any appear in asparagin-sulphate-phosphate solution to which 2 % 
 dextrose was added. 
 
 Oxygen relations. Liborius says (loc. cit. p. 172) that 
 such facultative anaerobes as Bac. crassus sputig, Bac. 
 pneumoniae, and Proteus vulgaris, which possess the 
 power to ferment sugar, do this equally well in the presence or in 
 the absence of oxygen. "Der B a c. p r o d i g i o s u s bietet den einzigen 
 Ausnahmsfall, daB Garung nur in den sauerstofffreien Kulturen 
 eintritt; aber auch hier ist nicht etwa die Garung ein Mittei, 
 dessen sich der Pilz bedient, um bei dem SauerstoffausschluB leben 
 und wachsen zu konnen, sondern er vermag ebensowohl in luft- 
 freiem Raum zu gedeihen, wenn gar kein garfahiges Material in Nahr- 
 substrat vorhanden ist. a My results on the anaerobic life of B. pro- 
 d i g i o s u s differ from those of Liborius and agree with those 
 of Ritter. In sugar bouillon B. prodigiosus grows, without 
 pigment, in the absence of oxygen. In sugar free bouillon no 
 growth takes place, although upon admission of air after fifteen or 
 twenty days development will proceed. Liborius' results can be 
 explained by the probable presence of muscle sugar in his so-called 
 sugarfree media. As I have shown above, absence of oxygen is 
 not necessary for gas production. 
 
 Temperature relations. B. prodigiosus develops at 
 37 1 / 2 C, but without pigment production, which is impeded at 
 a temperature of 35. Development is prevented by a tempera- 
 ture of 42 C. 
 
Nitrate reduction. B. prodigiosus, when grown in 
 nitrate solution , produces a marked reduction of nitrates into 
 nitrites. Grown in the fermentation tube, in sugarfree bouillon to 
 which 1 / KN0 3 has been added, further reduction is shown by 
 the appearance of gas bubbles at the end of the week. 
 
 Odor. The cultures of B. prodigiosus are characterized 
 by a strong odor of trimethylamine, although , S c h e u r len states 
 that this substance is not formed. It has also been stated that 
 the odor is absent in colorless races (Schottelius). It is absent 
 in non-proteid media. 
 
 B. prodigiosus II VIII. 
 
 Seven so-called B. prodigiosus cultures were obtained from 
 various sources (cf. prefatory list) for comparison with B. pro- 
 digiosus I. Cultures II and III agreed with the type in all 
 respects and were probably derived from it. B. p r o d i g i o s u s IV, 
 
 VI and VII were vigorous cultures showing characteristic lique- 
 faction of gelatin , coagulation of milk , red pigment with green 
 luster on agar and potato etc., but causing gas evolution in sucrose 
 as well as in dextrose bouillon. Agar colonies of B. prodigiosus 
 
 VII were sometimes spreading and proteus-like. B. prodi- 
 giosus V and VIII gave a less brillant pigment of a violet red 
 color without metallic luster. No. V produced a heavy orange red 
 membrane-like pellicle in sugar free bouillon, liquefied gelatin 
 more slowly, beginning with a cup-like depression, coagulated milk 
 only in 72 hours, but showed gas bubbles in dextrose, sucrose, 
 and even in lactose fermentation tubes sooner than any other 
 Prodigiosus culture, i. e. in 48 hours. B. prodigiosus VIII 
 produced a viscid growth in ordinary media, which formed long 
 threads when touched with the needle. It coagulated milk in 
 48 hours and liquefied gelatin rapidly, but produced no gas in 
 sugar bouillon. 
 
 B. ruber indicus (Koch, 50). 
 
 Isolated by Koch in India from the stomach of an ape, and, 
 according to K r u s e (52), again found byPasqualein Massua. I was 
 unable to obtain the descriptions of either of these investigators, 
 but that ofFraenkel (51) must correspond closely to the original, 
 since he relates how the organism was sent to the Berlin Labo- 
 ratory by Koch, between two pieces of filter paper in a letter. 
 It was subjected to all the fumigation which the sanitary police 
 deemed necessary for documents leaving a cholera country, was 
 "durchlocht, gechlort und geschwefelt", but survived. F r a e n k e 1 
 states that it differed from B. prodigiosus in developing pig- 
 ment at 37, and in its toxicity for guinea pigs and rabbits. 
 
 My two cultures, although evidently distinct for several years 
 (cf. prefatory list), were alike in every respect. They differed from 
 the Prodigiosus type as follows : 
 
 Gelatin stab, the liquefied portion colored red only at the 
 surface. Agar, colonies pink in 72 hours, 3 mm in diameter, edges 
 
slightly serrate, later spreading and red with green iridescence. 
 On slant agar and potato, pigment production usually poor, 
 growth luxuriant but dirty white. Unlike any other of the red 
 forms, B. ruber indicus produces pigment more readily on al- 
 kaline than on acid or neutral agar (cf. section on special media). 
 Bouillon, pellicle and sediment usually white, but in a peptone 
 and water solution vivid red pigment is formed. Milk, coagulum 
 completely peptonized in 10 days at 37 C. Gas, all C0 2 , is 
 formed from sucrose as well as from dextrose bouillon, but none 
 from lactose. Development with pigment takes place at 37 C. 
 Nitrate, reduced to nitrite and further to free nitrogen or 
 ammonia. Odor, not characteristic. 
 
 B. plymouth ensis (Fischer, 54). 
 
 Isolated from water and described by Fischer (1887). The 
 complete description is as follows: (Ein) "beweglich(er) Bacillus, 
 den ich in der Wasserleitung von Plymouth entnommenem Trink- 
 wasser fand und der sich nicht nur durch seine Gestalt (kleine, 
 dicke Stabchen mit abgerundeten Enden, kurze Faden bildend), 
 sowie durch die karmoisinrote Farbe des Pigments von den bisher 
 bekannten, einen roten Farbstoff bildenden Bakterien (Micro - 
 coccus prodigiosus, Bacillus ruber indicus Koch, und 
 Bacillus ruber Frank) unterscheidet, sondern auch durch eine 
 stark fadenziehende Beschaffenheit der Kulturen , sowie durch leb- 
 hafte Gasproduktion gut charakterisiert ist." Voges (55) (1893) 
 also made some observations on this form, which my results con- 
 firm and amplify. 
 
 The pigment formed by B. plymouthensis on ordinary 
 media could be distinguished from that of B. prodigiosus only 
 by its less vivid color and tendency to deteriorate into a violet 
 pink. Freshly rejuvenated cultures sometimes showed metallic 
 luster on agar, but, contrary to V o g e s' observations, not on potato. 
 The "fadenziehende" character, mentioned above, seemed constant 
 in B. plymouthensis I during two years' observation , after 
 which it disappeared. This character also appeared in a culture of 
 B. prodigiosus I, and is present in B. prodigiosus VIII 
 (cf. section on discontinuous variation). The main points of distinc- 
 tion between the Prodigiosus type and B. plymouthensis 
 are (1) slower liquefaction of gelatin beginning with a cupshaped 
 depression (cf. B. prod. V), (2) a vigorous (contrary to Voges) pro- 
 duction of gas, 7078 % of it C0 2 , in dextrose, lactose and suc- 
 rose bouillon. Gas, 42 % of it C0 2 , is also formed in a standard 
 asparagin sugar solution. Cultures ofB. plymouthensis I have 
 a strong fecal odor. 
 
 B. kiliensis (Breunig), B. ruber balticus (Kruse). 
 
 Isolated from water and described by Breunig (56) (1888). 
 A culture from Krai under the name B. ruber balticus corre- 
 sponds to the description of Breunig and to that of Laurent 
 (57), who worked on the variability of the "Bacille rouge de Kiel". 
 
10 
 
 A second culture, B. kiliensis, was atypical only in lack of the 
 characteristic pigment, which was revived on special media to the 
 violet red color without the usual green luster. These cultures 
 differed from B. prodigiosus as follows : 
 
 Morphologically larger, rodlets of a young potato culture 
 2,5 5 // in length, 0,60,8 /< in diameter; rodlets from an old 
 potato culture may reach 8,0 /i in length. Motility appears in 
 4 hours after inoculation on potato at 35 C, in 24 hours at room 
 temperature. Gelatin is rapidly liquefied, with a thick orange red 
 surface pellicle. B r e u n i g described the growth on potato as at 
 first sealingwax red and later like that of B. prodigiosus. My 
 cultures showed in 24 hours a slight growth of a red violet color, 
 which became luxuriant and darker until, in 10 days, it was heavy, 
 corrugated, and looked like iron rust. Green luster is often 
 seen. Bouillon cloudy, thick orange red pellicle, and red sedi- 
 ment. The production of gas by this form, so far as I can find, 
 has not been previously determined. It occurs readily in dextrose, 
 lactose, and sucrose bouillon, and unlike that of the forms so far 
 described, is only in small part (2028 ; ) C0 2 . In standard 
 asparagin solution with 1,0 / dextrose, gas to 14,3 of the tube 
 length was formed, none of it C0 2 . Development with pigment 
 occurs at 37 " C. The pigment is violet red and lacks the orange 
 red surface growth seen at room temperature. Nitrates are reduced 
 to nitrogen gas. Odor not characteristic. 
 
 B. miniaceus (Zimmermann). 
 
 Isolated in 1889 from water, by Zimmermann (59), who 
 has suggested that the organism seems identical with Dowdes- 
 well's B. rosaceus metalloides. Zimmermann described 
 it, however, and gave it the above name. Migula, commenting 
 on this form, said: "Zimmermanns Vermutung, dafi diese Art 
 identisch mit B. rosaceus metalloides ist, diirfte nicht rich tig 
 sein. Er schliefit sich eher an den Kieler Bacillus an." 
 
 Hoagland Laboratory, Brooklyn, furnished a culture, isolated 
 from water, which seemed identical with the B. miniaceus from 
 Krdl, except for a tendency to lose power of pigment production. 
 A second culture from Hoagland Laboratory, evidently identical 
 with the first, came into my hands as "B. rubrus", was colorless, 
 and could not be made to regain the chromogenic power. This 
 culture produced the typical amount of gas, 4045 / . 
 
 My cultures of B. miniaceus are more like B. ply mou- 
 th en sis than like B. kiliensis. Contrary to Zimmermann, 
 I find the bacillus motile in young cultures. Liquefaction of gelatin, 
 slower than B. plymouthensis, but not so slow as stated by 
 Zimmermann, i. e. begins within 5 days, and is complete in 
 three or four weeks. The liquid is red. Potato and agar, like 
 B. plymouthensis, metallic luster rarely seen and only on 
 glucose agar. Gas production like B. plymouthensis. Nitrates 
 reduced to nitrites only. No fecal odor. 
 
11 
 
 B. rutilus (n. sp.). 
 
 This organism was isolated in November, 1899, from the Illinois 
 River. One ccm of water was incubated for 24 hours in 0,55 carbol 
 broth, then plated in litmus lactose agar, where such a production of 
 pigment occurred that the plate was brilliantly colored. The red pig- 
 ment form grew luxuriantly upon isolation, arid, since it differed from 
 B. prodigiosus and from the others of the series, is here de- 
 scribed as a new species. Its vigor of growth and pigment pro- 
 duction have been slightly lessened by two years of cultivation 
 upon laboratory media. Its points of difference are as follows: 
 
 A short, actively motile bacillus, slightly larger on all media 
 than B. prodigiosus, but smaller than B. ruber balticus. 
 Gelatin, growth and liquefaction rapid, little pellicle, the whole 
 liquid vivid red. When first isolated, agar plate colonies always 
 showed pseudopodia-like ramifications; later, branching more rare, 
 or only on plates from old cultures. Growth and pigment best on 
 acid agar. No metallic luster ever seen on agar or potato. In 
 acid bouillon, the whole liquid colored red, no pellicle. The pre- 
 sence of dextrose and lactose increases the pigment, that of sucrose 
 does not. Milk, acid and coagulated in 24 hours, later peptonized 
 at 35 C. Gas production, in dextrose and sucrose bouillon, when 
 first isolated, 90 | of tube length, 65 % of this C0 2 . Later, 50 / 
 of tube length, all C0 2 . Nitrates reduced only to nitrites. Odor, 
 like B. prodigiosus. 
 
 B. amyloruber (n. sp.). 
 
 An organism which differed from B. prodigiosus, B. ruber 
 balticus etc., in pigment and in some other characters, was iso- 
 lated from Mississippi River water in 1901 ; because of its ability 
 to grow actively upon starchpeptone media it has been given the 
 above name. After passing through a summer upon neutral agar 
 the character of its growth was somewhat changed, tending to a 
 thin crusty or granular growth instead of one soft and luxuriant. 
 The pigmentation on ordinary media has undergone no deterioration, 
 remaining deep violet red. The chief points of deviation from the 
 forms already described are as follows: 
 
 Upon ordinary media the pigment is deep violet red, taking 
 orange color only on alkaline agar. Sugar free bouillon, little pig- 
 ment; sugar bouillon, colored deep violet red. Milk, peculiar; at 
 first, no change; later, a violet red coloration; after 15 days, a 
 tine red and white sediment of pigment granules and precipitated 
 casein, but no coagulation and no peptonization. No gas is evolved 
 in any sugar bouillon. Nitrates, reduced to nitrites. 
 
 B. fuchsinus (Boekhout and de Vries). 
 This name has been given to two different organisms; 1) to 
 a "new chromogenic bacillus" described by Boekhout and 
 de Vries in 1898 (60), and 2) to the red bacillus described but un- 
 named by Lustig in 1893 (8), named by Migula in 1900 (10). 
 Lustig's organism, which he described very completely, differs 
 morphologically from B. prodigiosus in that it is a rodlet two 
 
- 12 
 
 or three times as long as broad, and contains pigment granules 
 in the cell body. Its cultural features are like those of B. pro- 
 digiosus, with the exception of pigment production in the absence 
 of oxygen. This organism is called by Kruse (3) B. ruber 
 aquatilis. 
 
 Krai informed me that the B. fuchsinus sent out by him 
 was obtained from Boekhout and de Vries. According to the 
 description of these authors, their bacillus differs from B. pro- 
 digiosus in the following points: It is slightly longer, i. e., 
 1 1,5 u long. They describe it as non-motile, but later state that 
 in "Maizagar" it is longer and shows motility. It does not show 
 the metallic luster on ordinary agar, but does on potato and on 
 sodium tartrate agar. (B. prodigiosus often does not show it 
 on agar.) It peptonizes the casein in milk, and does not produce 
 gas in any sugar bouillon. 
 
 The culture which came to me from Krai showed no pigment 
 upon arrival , nor was I able to induce any pigment production 
 by various methods of rejuvenation, such as alternating series of 
 bouillon and gelatin cultures, growth on potato or on sodium 
 tartrate, agar etc., although the growth was rapid and luxuriant 
 on all media. After cultivating the organism for over a year, 
 I had begun to suspect that this form either was not B. fuchsinus, 
 or had lost its power of pigment production permanently, when I dis- 
 covered on a culture made on old dry agar a trace of red at the 
 top of the agar slant, where the agar was dryest By careful trans- 
 ference through a series of old dry agar tubes, I was able to 
 increase the pigment until it showed on the upper third and all 
 around the edge of the white agar growth, and also at the top of 
 growth on dry potato. This pigment was promptly lost, however, 
 when inoculation was made upon fresh media, and never showed 
 in gelatin or bouillon. My culture differed from the description 
 of Boekhout and d e Vries only in absence of pigment, and in 
 non-peptonization of casein 1 ). Nitrates are reduced to nitrites and 
 to free nitrogen gas. Gas is not formed from sugar bouillon. 
 
 B. ruber (Miquel). 
 
 This organism was sent to me from Krai's Laboratorium ; 
 the only description of it is contained in the following very kind 
 answer by Miquel to an inquiry concerning the organism: - 
 ,,Je n'ai jamais public* de travail sur le Bacillus ruber que vous 
 mentionnez .... Le bacille, qui possede les principaux caracteres 
 du Bacille rouge de Kiel, mais qui en differt par sa faculte 
 negative de liquifier la gelatine, fut donne" comme curiosit6 a 1'in- 
 stitut Pasteur d'ou il a Emigre un peu partout jusqu'au Labora- 
 toire de Dr. Krdl sans etre precede' d'un signalement quelqu'un. 
 Si le hazard me le faisait de nouveau rencontrer dans les eaux, 
 peut-etre en ferai-je Thistoire en raison de la beaute" de son pig- 
 
 U this paper is appearing in the Ccntralbl. f. Bakt. I receive through 
 the kindness of Dr. Boekhout a culture of B. fuchsinus showing luxuriant 
 red pigment. 
 
13 
 
 ment moidore; mais actuellement je n'en saurais dessiner une mo- 
 nographie precise: mes recherches sur ce micro-organisme datant 
 de plus de 10 ans." (1901). 
 
 I have completed Miquel's description as follows: 
 Morphology, a rodlet 23 /LI in length, often in chains of 
 several bacilli, non-motile, sporeless. Gelatin colonies, 48 hours, 
 small, irregular, finely granular, with well defined edges ; 72 hours, 
 show a peculiar corrugated, overlapping growth; the next day pig- 
 ment appears at the centre, and later they become deep violet red. 
 In gelatin stab, a red surface colony and a white needle track 
 growth; no liquefaction. 24 hours, surface colonies on agar 
 show a peculiar lined and cracked appearance under low power; 
 in 48 hours they are tinged red, and later look like B. prodi- 
 giosus colonies. Agar streak shows green luster and is like B. 
 prodigiosus or B. ruber kiliensis. Potato violet, red line 
 in 24 hours, later darker, often green luster. Does not spread 
 on potato. Blood serum not liquefied. Milk, no change except 
 pigmentation. Gas, 45 | of tube length in dextrose bouillon only, 
 79 / of gas C0 2 . Oxygen and temperature relations, like B. pro- 
 digious. Nitrates reduced to nitrites. No characteristic odor. 
 
 B. r ubricus (n. sp.). 
 
 In the autumn of 1901 three cultures were isolated in this 
 laboratory (University of Chicago) from the Mississippi and the 
 Missouri Rivers, which produced red pigment but showed marked 
 differences from B. prodigiosus and the cultures previously 
 described. These cultures do not grow rapidly, and the pigment 
 appears very slowly, the color beginning as pink or salmon pink, 
 and not attaining the characteristic brilliant red for some weeks. 
 Morphology, a small, slender, non-motile bacillus. Colonies, gela- 
 tin and agar, slow growing, small, round, non-characteristic, under 
 low power finely granular; color, yellow orange, deepening to red. 
 When first isolated, began to liquefy gelatin very slowly in ten 
 days. After a year's cultivation, the power of liquefying ordinary 
 gelatin had entirely disappeared. Agar slant, when dry and 
 growth limited, may develop bright red pigment in a few days; 
 when moist and spreading, may remain white or light pink for 
 weeks, gradually deepening in color. Potato slight or no growth. 
 Bouillon, cloudy, with pink pellicle. When first isolated, milk un- 
 affected; later, litmus milk cultures showed marked alkalinity. No 
 gas, nitrate not reduced, aerobic. May grow at 37 C, but better at 
 room temperature. 
 
 B. rufus (n. sp.). 
 
 Two cultures, much like B. r ubricus, were isolated at about 
 the same time and place. In pigment and in manner of develop- 
 ment this organism was hardly distinguishable from B. r ubricus, 
 but differed in showing luxuriant growth on potato, and in not 
 losing its power of liquefying gelatin slowly but completely. Milk, 
 unchanged or slightly alkaline in 15 days. 
 
14 
 
 B. ruber (Zimmermann). 
 
 This form was isolated from the Chemnitz water supply and 
 described by Zimmermann in 1890(61). Migula gives it the 
 name B. pseudoruber, since, he says, the name ruber had al- 
 ready been used by Frank, whose organism, he thinks, is not 
 identical with that of Zimmermann. Zimmermann himself 
 had mentioned Frank's form, but remarked, that identity with 
 his was impossible to determine because of the incomplete descrip- 
 tion of the former; he thinks that his organism is more likely to 
 be identical with Ei sen berg's red bacillus. 
 
 My culture of B. ruber Zimmermann, from Krai, differs 
 both from the original description and from that of Eisen- 
 b e r g 's bacillus (cf. Table X). It is non - liquefying, non-gas pro- 
 ducing, and non-luxuriant on potato. It differs from B. rubri- 
 cus and B. rufus in being an actively motile bacillus. Bouillon 
 shows a peculiar growth; no development is visible for three or 
 four days, then a thin pink pellicle forms on the surface which 
 sends floating cobwebby streamers down into the clear liquid. 
 This may still be seen after 26 days. Some pin-point pink colonies 
 attach themselves to the wall of the tube. Potato shows a slow 
 clear red growth, limited to the needle track. Litmus milk 
 becomes blue through alkali production. No development occurs 
 without oxygen , nor at 37 C. Blood serum not liquefied, nitrate 
 not reduced. 
 
 B. havaniensis (Sternberg). 
 
 Sternberg has unfortunately given this name to two different 
 organisms ; one, the color producing, he termed B. havaniensis (62), 
 the other, colorless, B. havaniensis liquefaciens. Kruse 
 and Migula describe the latter under the name B. havaniensis, 
 which properly belongs to the red form. Sternberg's descrip- 
 tion of the red form is as follows : A short oval bacillus, usually 
 in pairs, about 0,4 0,5 (j. in diameter. The cells are nearly sphe- 
 rical. It is an aerobic, non-liquefying, chromogenic bacillus, which 
 grows slowly at room temperature. On gelatin plate the colonies 
 are spherical, translucent, of a blood red color; on gelatin stab 
 there is an opaque carmine layer, with a scanty colorless growth 
 in the depths. On agar the growth is slow but continuous, of a 
 glistening red color, with wavy outlines. The organism frequently 
 fails to grow on acid potato, but sometimes develops on old dry 
 potato. Pigment is found only in the presence of free oxygen. - 
 Migula, in describing this organism, does not include it among 
 the red forms; he says that its growth on agar is brown, and that 
 it shows no growth on potato. 
 
 The culture here described is of unknown origin, having been 
 in the laboratory (University of Chicago), some years under the 
 name B. havaniensis. It agrees exactly with Sternberg's 
 description as far as that goes. Growth in bouillon is similar to 
 that described for B. ruber Zimmermann. Litmus milk is un- 
 
15 
 
 changed except for orange pigment at the surface. No gas is pro- 
 duced ; growth but no pigment occurs at 37 . It differs very little 
 from B. rubric us, i. e., only in bouillon and in milk. 
 
 B. lactis erythrogenes (Hueppe). 
 
 It was long ago observed in dairies that so-called bacterial 
 44 red milk" occured in one of two ways ; either red flakes appeared 
 on its surface, or the whole mass of liquid was colored red. The 
 former phenomenon is ascribed to B. prodigies us; the second 
 is usually due to an organism discovered in 1886 by Hueppe, 
 and described in 1889 by Grotenf eldt, (63) as B. lactis 
 erythrogenes. This organism, according to Grotenf eldt, 
 is a small rodlet, 11,4/4 long, non- motile and sporeless. 
 The gelatin colonies are small, round, and at first grey- 
 white, later yellow, as the gelatin becomes liquefied. Around 
 them the gelatin has a rose tint. A gelatin stab cul- 
 ture liquefies slowly from the top. After 1012 days the 
 liquefied portion is red, with a yellow sediment, while the solid 
 portion below is a weak rose color. The growth on potato 
 and agar is yellow, and after 6 8 days at 37 C, the pigment be- 
 comes a deep golden color. Bouillon is cloudy and yellow. Milk 
 undergoes a slow precipitation of casein, leaving a clear serum 
 which becomes blood red; the reaction is alkaline. The organism 
 is not pathogenic; the cultures are characterized by a sweet odor. 
 
 My culture of B. lactis erythrogenes, from Krai, agreed 
 closely with this description. Another culture, isolated in Novem- 
 ber 1901 from Mississippi River water, corresponded to the Krai 
 culture in all characters except that the color of the yellow pig- 
 ment was a shade lighter, with a tendency to appear much later 
 in the growth. The following details may be added to the descrip- 
 tion of these cultures: Growth on agar is moist, luxuriant and 
 yellow, while the medium becomes rose colored as in gelatin, and 
 even wine red. The yellow growth on potato shows often a slight 
 pink tinge, the potato becoming dark and discolored. Blood serum 
 not liquefied; no gas in sugar bouillon; no development without 
 free oxygen ; development with pigment at 37 C ; nitrates reduced 
 to nitrites. The sweet odor of the cultures is very noticeable. 
 
 B. rubefaciens (Zimmermann). 
 
 Isolated from the Chemnitz water supply and described by 
 Zimmermann in 1890(67). Characterized by a rose red color 
 which diffuses throughout solid media such as gelatin or agar. 
 Morphologically, a thin rodlet, 1 1.6 u long, often in chains of 
 two or three. Actively motile, no spores. Gelatin colonies ap- 
 pear as minute white dots in 48 hours; under low power, pearly, 
 thinner at the edge, which is well defined, finely granular. In gelatin 
 stab, small spherical white colonies occur along the needle track, 
 giving a characteristic appearance. The surface colony is yellowish, 
 and in old cultures a red tinge may be seen in the medium. No 
 
- 16 - 
 
 liquefactioo. Agar colonies, not characteristic in ten days, small, 
 white, with fragmented edges. An agar slant culture shows a 
 white, smooth, shining, somewhat luxuriant growth. In old cul- 
 tures the medium takes on a distinct wine-red color, clear and 
 transparent. Zimmermann does not specify this as true for 
 agar, only for gelatin and potato. A heavy cream white layer 
 forms on potato, which later becomes yellow brown. I observed 
 no rose color here, but a brown discoloration of the potato. 
 Bouillon becomes cloudy with a white surface pellicle; after 
 6 8 weeks it may show a slight reddish tinge. Litmus milk is 
 decolorized and acid, but coagulates at the end of ten days only 
 on boiling. No gas is formed, no growth at 37 C, nitrate reduced 
 to nitrite, facultative anaerobe. 
 
 B. lactorubefaciens (Gruber) (68). 
 
 Received from Gruber in November, 1902. Upon examination 
 it agreed closely with the original description. I found however, 
 that the deep growth in gelatin was sometimes arborescent, and 
 that the medium was tinged red. On agar and potato, a white 
 spreading growth. Bouillon is turbid, with pellicle and sediment. 
 The colonies are coli-like. Milk is made rose colored and very 
 slimy; litmus milk shows slight acidity, but does not coagulate at 
 room temperature. The organism does not develop at 37 C, which 
 fact, together with its behavior in milk, its lack of yellow pigment, 
 and its motility, distinguish it from B. lactis erythrogenes. 
 
 B. rutilescens (n. sp.). 
 
 Isolated from Mississippi River water in 1901. Its characters 
 connect it both with the Prodigiosus group and with the Lac- 
 tis erythrogenes group. Morphologically, an actively motile 
 bacillus, like B. rutilus and B. r ubefaciens, unlike B. lactis 
 erythrogenes. No spores. Gelatin plates show white, non 
 characteristic colonies which soon liquefy the gelatin. A stab cul- 
 ture is liquefied rapidly, with a white cumulus sediment, and a 
 white pellicle. Later the liquid portion becomes a beautiful clear 
 rose, and the floating pieces of sediment take on a pink tinge. 
 Agar colonies are often spreading, like those of B. rutilus or 
 B. ruber indicus, without pigment. Agar slant shows a luxu- 
 riant, smooth, moist, white growth, much like the pigmentless 
 culture of B. fuchsinus. Potato, luxuriant, white, and spreading. 
 Bouillon, marked turbidity, with white sediment and thin pellicle. 
 Litmus milk, at room temperature slightly acid, coagulating in 
 three days. At 37 C, coagulation in 48 hours, followed by partial 
 peptonization. Gas production, negative; facultative anaerobe, ni- 
 trates reduced to nitrites. Unlike B. rubefaciens, grows rapidly 
 at 37 C. 
 
 B. mycoides roseus (Scholl). 
 What seems to be the original description of this organism is 
 
17 
 
 a footnote to Grotenfeldt's article on B. lactis erythro- 
 genes (69) (1889), mentioning a bacillus isolated from earth by 
 Scholl, and studied in the laboratory of Hueppe at Wiesbaden. 
 The bacillus formed red felt-like colonies on gelatin, causing li- 
 quefaction. The gelatin had a red pellicle, but was not colored 
 throughout. Agar cultures were red in the dark. It grew quickly 
 at room temperature, and was morphologically like the anthrax 
 bacillus. 
 
 Ei sen berg (70), Kruse(3), and Migula(71) repeat this 
 description, the latter two authors adding only data as to solution and 
 spectrum analysis of the pigment as determined by Schneider (19). 
 Mace" (9 p. |256) mentions the organism. These are the only 
 descriptions that I have found. 
 
 My cultures, I and II, were identical in all reactions tested. 
 Morphologically B. mycoides roseus is usually smaller than 
 the anthrax bacillus, but like it variable in size, rodlets from 
 2 10 ju long occurring in the same culture. In very old agar 
 cultures, short, thick, often coccuslike, non-motile, no spores. Ge- 
 latin colonies are characteristic. They appear in three days as 
 minute white dots, under low power showing an opaque center and 
 edges broken or fringed as though crystallized; later the edges 
 lose their fringing and become smooth. In ten days the colonies 
 are 35 mm in diameter, somewhat creased and corrugated ; they 
 form slight depressions in the gelatin, but do not actually liquefy 
 it. Gelatin stab culture develops slowly a slight needle growth and a 
 dry, thick, corrugated pink colony on the surface. The needle growth 
 is often finely arborescent, like that of the colorless B. mycoides 
 figured by Lehmann and Neumann (7). Agar colonies appear 
 in 48 hours; under low power they show the characteristic fringed 
 edges seen in gelatin colonies. At five days they are pink and 
 small to the eye, less than 1 mm in diameter, edges smooth and 
 granular. Agar slant cultures show little development before 
 48 hours or three days. Then a salmon pink growth is seen, which 
 becomes dull, dry, and wrinkled, deepening in color as it gets 
 older, finally becoming vermilion. Potato, growth very slow, no 
 development for three or four days; at the end of ten days small 
 orange dots, or if the potato is kept wet, an elevated, warty, moist, 
 salmon pink growth. In 25 days a thick raised layer is seen, 
 which is more orange in color than on agar. Bouillon, slow de- 
 velopment, no turbidity. On the third day small round pink co- 
 lonies appear at the surface; at the end of ten days the surface 
 is covered with a thick agglomeration of salmon pink colonies, 
 some of which sink to the bottom as sediment. Milk, at the end 
 of ten days, shows only the characteristic salmon pink colonies 
 floating on the surface; after 20 days, decidedly alkaline. No gas, 
 no growth in the closed arm; growth and pigment nearly as good 
 at 37 C as at room temperature; nitrates reduced to nitrites. 
 
 B. mycoides corallinus (n. sp.). 
 
 This organism was isolated from Mississippi River water in 
 
 2 
 
18 - 
 
 1900, and has since been kept in stock in this laboratory (Uni- 
 versity of Chicago). Two years of artificial cultivation have some- 
 what changed its character, but it continues to show several 
 seemingly constant differences from B. inycoidesroseus, its 
 resemblance to which has led to the adoption of the name. 
 
 When first isolated, young cultures showed a large anthrax- 
 like bacillus, non- motile, sporeless; later the organism became 
 somewhat diminished in size. Gelatin colonies are characteristic, 
 but differ from B. mycoides roseus. They appear in three days 
 as minute points, which under low power have a peculiar woolly, 
 wispy look ; as they develop, they become pink, smooth, and raised. 
 Gelatin stab, slow development; a ten day growth is very charac- 
 teristic, a fine feathery development along the needle track, and a 
 raised, smooth, shining pink surface colony. The minute agar colo- 
 nies of 48 hours show microscopically the characteristic wispy fib- 
 rillar branching; high power shows that the branching is made up 
 of transparent beady ramifications extending in all directions. The 
 colonies are larger than those of B. mycoides roseus of the 
 same age. Agar slant culture is unlike B. mycoides roseus 
 in being smooth, moist, and salmon pink in color. Growth on potato 
 differs in the same way, the color deepening in 20 days to red. 
 In bouillon cloudiness appears in 24 hours; later the turbidity 
 increases, and a pellicle of small separate pink colonies covers the 
 surface, falls as sediment on shaking, and is re-formed. Litmus 
 milk shows strong alkali production and characteristic pigment. 
 Otherwise like B. mycoides roseus. 
 
 B. later ice us [?J (Adametz, 72). 
 
 I could not obtain the original description of this organism. 
 Migula (10) describes it as a non-motile rodlet, 35 times as 
 long as thick, slow growing and non-liquefying. Chester (1) adds 
 that the growth on agar is limited, moist, glistening, and reddish- 
 brown to yellowish-brown; bouillon is clear and alkaline, with 
 stringy sediment; potato, thin, moist, and reddish; litmus milk, 
 decolorized and coagulated; indol, negative; no growth at 36 C. 
 Lehmann and Neumann (7), who give a fuller description, 
 with plates, say that milk is not coagulated, the growth is from 
 vermilion to reddish brown ; no gas nor acid is formed from sugar, 
 but traces of indol occur. Their culture was isolated from air and 
 identified from Eisenberg's description (2). 
 
 My culture of B. latericeus, obtained from Krai, does 
 not agree with any of the above. Dyar (73) also notes the aber- 
 rancy of the culture which he received from the same source. 
 Dyar's culture, to which he gives the new name, B. fuse us 
 pallidior, agrees with that here described. 
 
 A short, non-motile bacillus, 11,3 n long, and 0,50,7 (i 
 broad, occurring single and in chains. Gelatin colonies after four 
 days small, granular, with slightly irregular and ragged edges. 
 Stab cultures show a slight needle growth, and on the surface a 
 
UN! 
 
 19 
 
 slow growing dry white colony, which after weeks lines a cup-like 
 cavity with a thin dry spreading cream pink growth. No other 
 evidence of liquefaction occurs than the cup shaped depression. 
 Agar colonies are dry and shining to the eye; under low power 
 the edge is ragged, showing the individual rodlets pushing out 
 into the surrounding medium, Agar slant and potato show at 
 first a dry shining whitish layer, which later becomes "crusty", 
 wrinkled, and dull pink. Bouillon remains nearly clear, develop- 
 ment taking place in a thick surface pellicle of paraffin-like con- 
 sistency, from which flakes fall to the bottom of the tube on 
 shaking. Litmus milk, not coagulated, but shows intense alkaline 
 reaction and peptonization after a few weeks at 35 C. Aerobic, 
 non-gas producing, nitrates reduced to nitrites, slight growth at 
 37 C. 
 
 B. rubropertinctus. 
 
 In his experiments with acid-resisting organisms, Grass- 
 berger (74) made, in 1899, from butter and from guinea pigs inocu- 
 lated with butter, six isolations of the bacillus described below. 
 My culture, obtained from Krai in 1901, agress in biological 
 characters with Grassberger's original notes. As he gave it 
 no name, I have called it on account of its staining reaction, 
 B. rubropertinctus. 
 
 Grassberger describes a 24 hours agar culture as showing 
 rods 1,53,0 ^ long, having no trace of acid resistance when 
 stained. Older cultures occasionally show longer bacilli, which 
 retain the stain slightly when treated with 3 % ac id alcohol, but 
 never evince the true tubercle bacillus reaction. I found that a 
 ten day potato culture, when stained on a cover glass together 
 with B. c o 1 i by hot carbol fuchsin , washed several times with 
 10 % H 2 S0 4 , and counter stained with methylene blue, resisted 
 the acid perfectly, remaining bright red in contrast to the blue 
 B. coli. The bacilli could not be mistaken for B. tuberculosis, 
 being much shorter and thicker. 
 
 Gelatin plate shows characteristic colonies, the deeper ones 
 ovoid in shape and granular, ttye superficial colonies irregular, with 
 crenate edges, folded surface, and red color. Stab culture, slight 
 needle growth and orange red surface colony as above, no lique- 
 faction. Agar colonies, very slow, being just visible to the naked 
 eye in five days; uniformly granular, and irregularly triangular. 
 On agar slant, growth lustreless, dry, and spreading, later wrinkled 
 and vermilion red. Grassberger records one culture that was 
 moist. Potato development, slow but constant; at the end of ten 
 days orange red, rough, granular, and moist. Bouillon, clear save 
 for slight cloudiness at the top; a salmon pink pellicle is formed, 
 which is constantly renewed as it sediments on shaking. Litmus 
 milk shows no change except for the development of a pink pellicle; 
 B. rubro pertinctus is not gas-producing, grows at 37, is 
 aerobic. Grassberger notes slight indol production and cauli- 
 flower-like odor. My culture did not show these characters. 
 
20 
 
 B. mesentericus ruber (Globig). 
 
 Isolated by Globig, 1888 (75), from potato. Described as 
 a slender, motile, bacillus, with oval, very resistant, spores. Gela- 
 tin colonies, round and yellow in the depths; on the surface 
 showing a fringe or halo of fine network, which breaks down in 
 34 days and liquefaction begins. Gelatin stab, funnel shaped 
 liquefaction. Agar colonies are non - characteristic. Agar streak, 
 dirty white and slightly wrinkled growth. On potato a dry growth 
 of a beautiful pink color. Globig described bouillon as clear, 
 with a thick pellicle; my cultures showed cloudiness and pellicle. 
 Litmus milk, curdled and acid. No gas is produced, nitrates are 
 reduced, growth with rose color at 37 C. 
 
 Two cultures from Krdl, 1900, 1903, differed from the above 
 description in not showing spores. Three cultures isolated from 
 the Mississippi River water at different times were used as the 
 basis of this description. 
 
 C. Comparatire and Experimental Study. 
 
 I. Color determination of bacterial pigment 1 ). 
 
 The increasing tendency towards the adoption of definite terms 
 of positive, negative, or quantitative value in bacterial descriptions 
 has not been generally extended to the determination of color 
 produced by bacteria. The pigmentation of an organism still 
 furnishes an opportunity for a more or less lax and undiscrimina- 
 ting nomenclature. Thus, among the red series one whole classi- 
 fication has been made on the basis of such divisions as these : 
 "Pigment carmine", "pigment flesh-colored," "brick-red", "reddish", 
 "rose-colored", "salmon-pink", "yellowish-reddish", "brownish-red", 
 "pinkish", "reddish-pinkish", "blood-red", "red-brick-red". These 
 distinctions may call up well defined color pictures to individual 
 workers, but it is evident that there are difficulties in the way of 
 fitting a new chromogenic organism to such an imaginative scheme. 
 
 In default of a more exact method, statistical biologists have 
 for some time employed a color top 2 ), upon which discs of the 
 primary colors may be arranged, showing sectors of definite pro- 
 portions ; when the top is rotated rapidly the colors blend and give 
 the intermediate tints. Any color may thus be matched, and the 
 percentage of primary colors which go to make it up very closely 
 determined. This method is easily applicable to bacterial colors, 
 and has been adopted in this study. Other color-terms appearing 
 
 1 ) The chemical nature of bacterial pigment, its solubility, and its spectrum 
 analysis has been discussed at length by Schroter (29), Cohn (30), Griffiths 
 (39), Scheurlen (43), Schneider (19), Rosenberg (45), Kraft (49), and 
 others. 
 
 2) The Milton Bradley color top has standard colors of the following wave- 
 lengths: Bed, 656061; orange, 606-611; yellow, 577582; green, 514519; 
 blue, 467472; violet, 419 424. For method cf. Davenport , C. B., Statistical 
 Methods. New York, 1899, p. 9. 
 
Vermilion 
 Orange red 
 Salmon pink 
 Pink 
 Violet red 
 Ked 
 Dark red 
 
 30 
 45 
 50 
 50 
 80 
 90 
 100 
 
 70 
 55 
 25 
 25 
 15 
 10 
 
 21 
 
 here are either quoted or applied to the culture media in distinction 
 from the bacterial pigments. 
 
 One difficulty, however, in determining bacterial pigment, is 
 the possible range of variation in any one organism under influence 
 of preliminary cultivation, reaction of media, and age of culture; 
 so that one color-determination may be insufficient for general 
 description. Neither can the mean of several determinations be 
 specified as the typical color of a given organism. But, allowing 
 for occasional degenerate or pigmentless cultures, if an organism 
 has been put through the regular course of rejuvenation and then 
 grown on slant agar of definite composition and reaction, the pig- 
 ment of young and of ten day old cultures can be fairly well charac- 
 terized. The appended tables will give an idea of the results of 
 this method; and the terms used in this paper to designate the 
 different reds will have definite meaning as follows : 
 
 Bed Orange White Blue 
 
 25 
 
 22 3 
 
 5 
 
 (see Table I p. 22.) 
 
 Of the cultures producing "insoluble" pigment on agar, which 
 are studied here, a division may be made into three groups, accord- 
 ing to color of pigment. 
 
 I. The B. prodigiosus group, including 
 
 B. prodigiosu s, 
 
 B. ruber indicus, 
 
 B. ruber plym outhensis, 
 
 B. kiliensis (B. ruber balticus), 
 
 B. miniaceus, 
 
 B. rutilus (n. sp.), 
 
 B. arayloruber (n. sp.), 
 
 B. fuchsinus, 
 
 B. ruber miquel. 
 
 The members of this group develop on agar a pigment in 
 mass, which shows a large percentage of pure red, with varying 
 quantities of orange and sometimes a small amount of blue, which 
 gives a violet tinge, or of black. They are characterized by the 
 fact that the amount of orange diminishes as the cultures age; 
 at the same time there is an addition of black, i. e., the cultures 
 grow darker. This group includes the "carmine", "blood red", 
 and "violet red" cultures. 
 
 II. The B. rubricus group, including 
 
 B. rubricus, 
 
 B. ruber zimmermann, 
 
 B. ha vaniensis, 
 
22 
 
 B. rufus (n. sp.), 
 
 B. rosaceus metalloides. 
 
 Since these cultures are slower in development, the pigment 
 appears somewhat later than in the organisms of group I. In 
 young cultures a large percentage of orange is present, and the 
 cultures never grow black, but keep the orange red tone. Here 
 are included "orange red", and "yellowish reddish" cultures. 
 
 Table I. 
 
 ROW Blue Blk V 
 Agar slant, 48 hrs. (1,5 % 4- ) 30 70 
 
 5 da. 75 25 (met. lus.) 
 
 ,, 10 
 
 Potato 48 hrs. 
 10 da. 
 
 Gel. stab (liq.) 
 Agar slant, 48 hrs. (1,5 / 
 ,, ,, 10 da. 
 surface 
 depth 
 
 Potato 48 hrs. 
 6 da. 
 
 Gel. stab. 10 da. (liq.) 
 
 10 da. (pellicle) 
 Agar slant, 24 hrs. (l,5<>/o +) 50 40 
 48 80 20 
 
 10 da. 68 14 
 
 nearly black 
 90 10 
 
 B. prodigiosus. 
 
 B. ruber balticus. 
 
 90 10 
 85 15 
 60 10 
 90 10 
 +) 85 15 (met. lus.) 
 
 30 (m. 1.) 
 
 B. rutilus (n. sp., 1900) 
 
 65 35 
 100 
 80 15 
 95 2 1 /, 
 90 10 
 70 30 
 
 5 
 
 2V, 
 
 (m. 1.) 
 
 10 
 
 3 15 
 
 10 
 Gel. stab. 10 
 
 B. ruber miquel. 
 
 (liq.) 
 
 Agar slant, 48 hrs. (1,5 % +) 80 20 (met. lus.) 
 
 B. ruber indicus. 
 
 Potato 
 Gel stab. 
 
 85 10 
 62 26 
 68 22 
 80 20 
 
 10 da. 
 48 hrs. 
 10 da. 
 
 10 (colony) 
 Agar slant, 48 hrs. (1,5 / ) 70 25 5 
 
 10 da. 80 10 
 
 Potato 5 30 
 
 Gel. stab. 10 (pellicle) 75 25 
 
 i, 10 (liq.) 100 
 
 B. ruber ply mouthen s is. Agar slant, 48 hrs. (1,5 / +) 57 35 
 
 10 da. 75 20 
 
 Potato 48 hrs. 30 22 23 
 
 10 da. 33 35 10 
 
 Gel. stab. 10 (pellicle) 80 20 
 
 >. , 10 (liq.) 100 
 
 B. rubricu s (n. sp.) (slow) Agar slant, 10 days 6330 2 
 
 B. havaniensis 10 55 45 
 
 B. rosaceus metalloides 10 5743 
 
 B. mycoides roseus 3 (1,5 / c +) 17 18 
 
 5 15 35 
 
 10 
 
 Potato 10 
 
 B. mycoides coral, (n.sp.) Agar slant, 10 
 
 Potato 10 
 
 12 
 10 
 
 10 
 
 (m.l.) 
 
 70 
 
 25 
 22 
 
 42 35 
 
 ,. (wrinkled) f>7 33 
 (1,5%-) 50 25 
 , (smooth) 28 42 
 
 III. The B. mycoides roseus group, including 
 B. mycoides roseus, 
 B. mycoides corallinus (n. sp.), 
 B. rubropertinctus, 
 B. latericeus (?). 
 
 4 
 
 12 
 
- 23 - 
 
 This group differs from the last in the presence of a con- 
 siderable percentage of white , with sometimes a trace of yellow. 
 Here would belong the so-called "salmon pink", "coral pink", 
 "rose", or "flesh colored" cultures. 
 
 Cultures producing "soluble" red pigment may be classed as 
 the Lactis erythrogenes group, including 
 B. lactis erythrogenes, 
 B. rutilescens (n. sp.), 
 B. rubefaciens, 
 B. lactorubefaciens. 
 
 B. mesentericus ruber is peculiar in producing its pink 
 or red pigment only on potato, not upon agar. 
 
 The term "Prodigiosus group" as used below, refers then to 
 the series of Group I as described. 
 
 II. Variability in the Prodigiosus group. 
 1. Introductory. 
 
 In the discussion of variability or variation as regards bac- 
 teria, several complicating factors are present. In the first place, 
 the facility with which bacteria, more than any other class of or- 
 ganisms, respond and adapt themselves to changes in the nature 
 of their environment is a constant character in their biology. 
 Again, a bacterial type, as we assume it, is more or less artificial, 
 developed and maintained by our methods of culture, which are so 
 arranged as to reduce or eliminate variation. And the old simple 
 distinctions between typical varieties are now complicated not only 
 by the natural variability of the organisms, but by the conception 
 of intermediary paratypes, each with its own possibilities of 
 variation. 
 
 The variability of bacteria, whether manifested spontaneously 
 or under compulsion, seems to find its expression principally in 
 the loss of certain characters or in their return after loss. If, for 
 instance, B. anthracis be exposed to a temperature of 42, 
 B. tetani to a gradual admission of oxygen, orB. prodigiosus 
 to the action of light, the organisms will all live and develop, but 
 one will lose its power of sporulation, another its virulence, the 
 other, its power of pigment production; and unless the abnormal 
 conditions be maintained for many generations, and the process 
 fostered by artificial selection, the organisms will, upon restoration 
 to their usual environment, revert to their original "normal" type. 
 These and many similar observations indicate that bacteria have a 
 certain number of biological characters, without which they may 
 continue to live; that these characters may be lost as a result of 
 environmental modification, but are so far typical that they tend 
 strongly to return. 
 
 This "tendency to return" finds its nearest explanation quan- 
 titatively, that is, in considering as a factor in variation not only the 
 effect of the environment upon the organism , but also the nature 
 of the compound of characters which we term a type. The aber- 
 
24 - 
 
 rant or white forms among the red, for example, may be considered 
 as due to sudden or irregular predominance of characters always 
 present, though latent or much in the minority; and the problem 
 before the student of variability is the determination of the "lowest 
 terms" to which an organism can be reduced, the discovery of the 
 minimum and the maximum of characters which can be found to 
 belong to each type. 
 
 The only means at our command for such investigation 
 is the modification of the nutritive medium. Such culture media 
 as agar, the composition of which is uncertain, do not give 
 definite results; and I have employed, as set forth below, 
 compounds whose elements and arrangement are more accurately 
 known. Whatever modifications of the organism, i. e., what- 
 ever response, by disappearance of characters, has followed change 
 in the environment, I have set down under the general head of 
 range of normal variation, reserving the term discontinuous 
 variation or mutation for the sudden appearance of by-forms with- 
 out any apparent cause. For such sports I do not offer expla- 
 nation. They may be due to a phenomenon parallel to what Wei s - 
 mann, speaking of budding, calls "abnormal differential nuclear 
 division", or they may arise in response to physical external causes, 
 confined to a very limited area, and invisible to us. But along 
 with the cases of "discontinuous variation" in the higher organisms, 
 they offer an interesting problem in the origin and differentiation 
 of varieties. 
 
 2. Discontinuous variation or mutation. 
 
 Variations of bacterial cultures, apparently spontaneous in 
 character, have been frequently noted. D y a r (65) considered that 
 when tubes were filled with media from the same flask, inoculated 
 at the same time from the same culture, and grown on the same 
 shelf, variation resulting in such a series was "discontinuous". The 
 possibility of contamination in bacterial cultures which may thus 
 suddenly vary is always a question, which can only be decided by 
 testing the new variety through a sufficient number of unchanged 
 differential characters, as was done by Dyar in studying a "crusty" 
 variety of B. lactis erythrogenes. The tendency, upon plating 
 such a variety, for some of the colonies to revert to the parent 
 type may be viewed as proof of the true nature of the variation. 
 
 Among chromogenic cultures the most frequently observed 
 "sport" variation is in the appearance of colorless colonies upon 
 a plate where the majority of colonies are normal. Such colonies 
 are of course more numerous in plates made from old or dege- 
 nerate cultures, and decrease gradually with successive transferences. 
 Thus, five B. prodigiosus cultures which were obtained from 
 different laboratories showed the following variations in the early 
 platings. All the plates were made in the same way, and were 
 second dilution. The original agar cultures were evidently young, 
 were all growing well, and were all pink or red in color except 
 
25 
 
 No. V, which showed no pigment, and, as I was informed, had not 
 for at least two months back. The first result on 48 hour agar 
 plate was: 
 
 B. prod. IV, 200 small colonies, apparently all orange red. 
 
 B. prod. V, 2 pink colonies, 48 white. 
 
 B. prod. VI, 300 to 400 colonies, all red. 
 
 B. prod. VII, 35 soft spreading white colonies, 3 pink. 
 
 B. prod. VIII, 5 smooth round colonies, all violet red. 
 
 All the agar streak inoculations from red colonies, and some 
 from white ones, gave ordinary red cultures of varying intensity; 
 and it was evident that the number of abnormal white colonies which 
 appeared as "sports" on the plates were in each case only an indi- 
 cation of the degree to which the colorless variations of the original 
 cultures had gained an ascendency over the red type through con- 
 tinued unfavorable conditions, probably because of long intervals 
 between transferences. That this was the case was shown by a 
 second plating after rejuvenation, fifteen days later. The results of 
 this were: 
 
 B. prod. IV. 400 brilliant vermilion colonies. 
 
 B. prod. V, 50 violet red colonies, 5 white ones. 
 
 B. prod. VI, all red. 
 
 B. prod. VII, 683 colonies, some spreading, all vermilion. 
 
 B. prod. VIII, 26 smooth violet red colonies, 1 white. 
 
 There are, however, exceptions to the good results of rejuve- 
 nation, unless plating and careful selection of colonies is a part of 
 the process. It sometimes occurs that an old culture on neutral agar 
 which has stood in the stock case two or three months will give a 
 brillant pigment on the first transference to neutral agar again, while 
 successive inoculations will seem to diminish the pigment production. 
 The first vigor may be the result of natural selection, but I have 
 no explanation to offer for the later deterioriation in this case. 
 
 Light colored or colorless colonies which appear as discontinuous 
 variations upon plates often give rise to apparently constant varie- 
 ties. Such a colony of B. ruber miquel produced a luxuriant 
 white agar streak, which showed only a few pin-point dots of red. 
 This was allowed to grow for several weeks, and the next and 
 several future transfers gave pure white cultures with all the other 
 characters of B. ruber miquel. Davis 1 ) notes "sports" of B. r o s a - 
 ceus metalloides which gave rise to dark and to light colored 
 varieties. 
 
 Among my series several instances of discontinuous variation in 
 mass cultures have appeared. A "crusty" variety of B. amylo- 
 ruber occurred, as in the case of Dyar's B. lactis erythro- 
 genes, after a summer's storage. The original culture had not 
 become contaminated, the pigment of the wrinkled crusty culture was 
 identical in violet red color and rapidity of development with that 
 
 1) Davis, N. F. (Science, Vol. XIII. 1901. p. 324.) 
 
26 
 
 of the original, and all the other characters were true. Upon plating, 
 some colonies gave rise to the original soft smooth growth ; a series 
 of cultures made after exposing the variety for varying lengths^ of 
 time to the sunlight also showed one tube like the original, a tube 
 made after 30 minutes' exposure. This result is explicable on the 
 theory of the selective action of sunlight, as noted below. 
 
 Variations in colony contour, noted in the case of B. ruber 
 indicus, B. rutilus, B. fuchsinus, B. amyloruber, and 
 rarely for B. kiliensis, where proteus-like and round surface 
 colonies appeared on the same plate, are to be explained partly 
 through physical conditions of the media, and partly by spontaneous 
 variations which arise in the viscidity of the capsular envelope or 
 in the motility of the organism. Agar streaks from the proteus 
 colonies were sometimes slightly more spreading, but the next plate 
 might show total reversion to the round type. 
 
 B. plymoutheusis is recorded in the original description as 
 differing from B. prodigiosus in marked viscosity on agar and 
 potato cultures. Dyar (loc. cit.) uses viscidity of B. plymouthen- 
 s i s to distinguish it from B. prodigiosus and B. rosaceus 
 metalloides. My culture also differed in producing gas in lactose 
 and sucrose bouillon and in standard asparagin dextrose solution, 
 as well as in a strong fecal odor. During a two years' obser- 
 vation of this culture, viscosity seemed as constant a character of 
 B. plymouthensis as any other of these differences. But the 
 next year, upon revival of the cultures after two months' summer 
 storage, B. prodigiosus I was found to evince the agar culture 
 viscosity of B. plymouthensis. Contamination naturally suggested 
 itself as first explanation, but plating and examination showed the 
 prodigiosus culture to be true in all other respects as noted 
 above, and it was necessary to ascribe the viscosity to a variation 
 which had arisen in the old summer culture and become dominant 
 accidentally in the first plating. Three different cultures now show 
 this peculiarity, the third, B. prodigiosus VIII, presenting it when 
 received at the laboratory. These observations make it necessary 
 to drop the character of viscosity or capsule formation as differen- 
 tial for B. plymouthensis. 
 
 In general, what we are in the habit of regarding as important 
 biological characters are not subject to sudden or spontaneous vari- 
 ation; i. e M the power of liquefying gelatin, of producing gas, or 
 of coagulating milk, does not appear or disappear abruptly with no 
 apparent cause. As has been observed in varieties appearing in the 
 same culture of B. coli 1 ), the variants are chiefly due to a 
 morphological change, such as the production of more or less of the 
 capsular substance upon which often depends the configuration of 
 surface colonies, or to change in an easily disturbed physiological 
 character such as excretion of pigment. 
 
 1) Smith, T., and Reagh, A. L. The agglutination affinities of rela- 
 ted bacteria parasitic in different hosts. (Journ. ofMed. Research, Vol. IX. 1903, 
 p. 270.) 
 
27 
 
 3. Range of normal variation. 
 
 a) Growth and pigment on ordinary culture media. 
 
 Morphology. 
 
 All the cultures of the Prodigios us group, except B. kilien- 
 sis and B. ruber miquel, are small, actively motile bacilli. 
 B. kiliensis is distinctly larger than B. prodigiosus, while 
 B. ruber miquel is larger still and non-motile. None have spores. 
 A gelatinous capsule is often present in B. prodigiosus and 
 B. ruber plymouthensis. All of these organisms tend to be 
 somewhat larger on solid media, especially on potato. 
 
 B. prodigiosus and B. kiliensis showed peritrichial flagella ; 
 the others were not examined for flagella. 
 
 Cultural features. 
 
 Gelatin. Plate colonies vary but slightly beyond the diffe- 
 rences in appearance due to variation in the viscosity of the medium. 
 In general the colonies are all like those described for B. pro- 
 digiosus, with slight variations as to time and manner in which 
 pigment and liquefaction appear. B. ruber miquel only, does not 
 liquefy gelatin. The same variations in time and degree of lique- 
 faction are seen in gelatin tube cultures, even in parallel inocu- 
 lations made at the same time, into the same lot of gelatin and 
 from the same culture. This is, however, not an unusual variation 
 in a series of tubes inoculated from one colony, and is probably due 
 in part, as shown by W hippie 1 ), to slight physical disturbances 
 in the action of the proteolytic enzyme. 
 
 A gar. Variation in the agar colonies, principally in contour 
 and in coloration, is due to the same causes as in the gelatin colo- 
 nies. Proteus- like colonies often occur, i.e., in B. ruber indicus, 
 B. rutilus, B. fuchsinus, and rarely in B. kiliensis, but the 
 usual Prodigiosus form is round. Pigment usually appears in 
 granular masses throughout the colony, but often the colonies show 
 fine concentric rings of pigmentation, with darker or lighter centres. 
 My attempts to make accurate colored reproductions of these proved 
 futile, since they are quite inconstant. One plate of B. prodigio- 
 sus IV may be normally and uniformly pigmented; on another all 
 colonies may become red from the edges inward, leaving at first a 
 white centre; other cultures may have violet red centres and white 
 edges. It is noticeable in such variations that they do not occur 
 on the same plate, i. e., they are regular responsive, and not sport 
 variations. 
 
 Potato. The tendency to consider potato as a rejuvenating 
 medium for B. prodigiosus is borne out by the vigorous growth 
 and pigmentation of B. prodigiosus I VIII on this medium, 
 cf. also B. kiliensis, rutilus, amyloruber, and ruber 
 miquel. For B. ruber indicus, B. plymouthensis, and 
 B. miniaceus, however, potato cultures were unsatisfactory for 
 chromogenesis. 
 
 Bouillon. Dense turbidity is always produced in bouillon by 
 
 1) W hippie, G. C., On the physical properties of gelatine, etc. (Techno- 
 logy Quarterly. Vol. XV. 1903. p. 159.) 
 
 \ 
 
 ** f> - 
 
 V* 
 
28 
 
 all of these cultures, but great variation is shown in the amount of 
 pigment elaborated and in the formation of pellicle. The amount of 
 sugar present in the medium has an effect upon pigment production, 
 as noted in the descriptions of the separate cultures; the reaction 
 of the bouillon is also a feature, more pigment being produced ir. 
 bouillon of slightly acid reaction. Usually in sugar free neutral 
 bouillon B. prodigiosus I IV, VI, VII, and B. ruber miquel 
 show slight coloration of the liquid and a red surface ring, but 
 little true pellicle ; B. k i 1 i e n s i s and B. prodigiosus V give thick 
 orange red surface membranes, while B. plymouthensis,B. raini- 
 aceus, and B. prodigiosus VIII show color only in a pink or 
 violet surface ring, and B. ruber indicus usually lacks pigment 
 entirely in ordinary meat bouillon but produces it in abundance iu 
 a peptone solution. On the other hand B. rutilus and B. amylo- 
 ruber color the entire liquid deep red, in observing which fact 
 we may remember their recent isolation. 
 
 Milk. All except B. amylo ruber and B. ruber miquel 
 acidify milk in 24 hours and coagulate it in from 24 (B. rutilus) 
 to 72 hours at room temperature. Some of the cultures show pep- 
 tonization of the casein. B. amyloruber does not coagulate, but 
 precipitates the casein, while B. ruber miquel produces no change 
 in milk except that of red pigmentation. Almost no variation is seen 
 in these reactions in milk. 
 
 Gas production. The appended table shows that great vari- 
 ation is evinced in this respect, not only in the group, but in the 
 same organism at different times, with different stocks of bouillon. 
 The table gives only the limits of numerous determinations made 
 with neutral 1,5 /o dextrose bouillon. 
 
 Table II. 
 
 
 Dex 
 
 Per cent, 
 of Gas 
 
 trose 
 
 Per cent. 
 ofC0 2 
 
 Lac 
 
 Per cent, 
 of Gas 
 
 :tose 
 
 Per cent. 
 ofC0 2 
 
 Sacci 
 
 Per cent, 
 of Gas 
 
 larose 
 
 Per cent. 
 ofCO 2 
 
 B. prodigiosus I, II, III 
 
 034,5 
 
 100 
 
 
 
 
 
 IV 
 
 10 
 
 
 
 
 
 
 10-20 
 
 
 V 
 
 70 
 
 55 
 
 32 
 
 20 
 
 70 
 
 50 
 
 VI 
 
 40 
 
 98 
 
 
 
 
 40 
 
 98 
 
 VII 
 
 1020 
 
 
 
 
 
 
 1020 
 
 
 VIII 
 
 __ 
 
 
 
 
 
 
 
 
 
 
 B. ruber indicus I, II 
 
 30-70 
 
 100 
 
 
 
 
 
 2025 
 
 100 
 
 B. kiliensis (B. r. bait.) 
 
 30-40 
 
 26-28 
 
 27 
 
 21 
 
 30 
 
 20 
 
 B. plymouthensis I, II 
 
 7078 
 
 7078 
 
 38-42 
 
 7072 
 
 2530 
 
 7075 
 
 B. miniaceuB I, II, III 
 
 4000 
 
 40-05 
 
 36-40 
 
 3557 
 
 30-53 
 
 2070 
 
 B. rutilus (n. sp.) 
 
 2891 
 
 100-65 
 
 
 
 
 
 6-88 
 
 100-60 
 
 B. ruber miquel 
 
 3446 
 
 7779 
 
 
 
 
 
 
 
 B. amvloruber (n. sp) 
 
 __ 
 
 
 
 ___ 
 
 
 
 
 
 
 
 and B. fuchsinus 
 
 
 
 
 
 
 
 It is to be remarked that, except in the case of B. rutilus, 
 th relation of C0 2 to the total gas produced remains fairly con- 
 stant for each organism. B. rutilus produced 6065 %> C0 2 at 
 first, but with gradual loss, after isolation, of the power to produce 
 
29 
 
 a large amount of gas, it seemed also to lose the power to form 
 anything but C0 2 . B. prodigiosus I usually failed to produce 
 gas in 1/ dextrose, 1,5 2 | being more favorable. 
 
 Oxygen and temperature relations. All of this group 
 are facultative anaerobes, but grow without pigment in the absence 
 of oxygen. Only B. ki lien sis and B. ruber indicus produce 
 pigment at 37 C, although all are able to grow at that temperature. 
 
 Indol production, nitrate reduction, odor. No 
 indol is formed by the members of this group. Nitrate is reduced 
 to nitrite in each case and often to free gas. The trimethylamine 
 odor is often present in cultures of the Prodigiosus group, and a 
 strong fecal odor is characteristic ofB. plymouthensis, B. pro- 
 digiosus V, and VIII. 
 
 B. ruber indicus only is said to be pathogenic for labora- 
 tory animals. 2 ccm of a 48 hour bouillon culture inoculated intra- 
 peritoneally killed a mouse in 48 hours. Unfortunately I was unable 
 to make an autopsy. 20 ccm of a 48 hour agar suspension failed 
 to produce any effect upon a guinea pig 1 ). 
 
 b) Growth and pigment on special solid media. 
 
 The earlier investigators of red chromogenic bacteria, Ehren- 
 berg (26), Fresenius (27), and Cohn (30), concerned them- 
 selves chiefly with the systematic position of B. prodigiosus; Erd- 
 mann (28), and Schroeter (29) worked with the chemical nature 
 of the pigment; Schottelius (35) was the first to pursue ecolo- 
 gical studies upon the pigment production, without, however, much 
 attention to the composition of the cultural media. His conclusions 
 as to the conditions necessary for pigmentation were 1) a sufficient 
 supply of atmospheric air, 2) a suitable temperature. Wasser- 
 zug (37) experimented upon the effect of alkaline and of acid media, 
 obtaining colorless races in alkaline bouillon. K uebler (38) repeated 
 Wasserzug's procedure , but contradicted him and confirmed 
 Schottelius in asserting the non-permanency of white cultures 
 obtained by high temperature and alkaline media. 
 
 The next important paper on the subject was that of Gale- 
 otti (15), who studied eight chromogenic organisms, among them 
 B. prodigiosus, L us tig's "red bacillus", and B. lactis ery- 
 throgenes. He found that B. prodigiosus gave less pigment 
 in liquid media than in solid, but that this was not due, as Wasser- 
 zug had thought, to lack of oxygen, since an atmosphere of pure 
 oxygen produced no better chromogenesis. He decreased the amount 
 of peptone in the agar, and inferred that a scarcity of proteid did 
 not prevent pigment production. B. prodigiosus was the only 
 organism of his series in which pigment production could be impeded 
 
 1) Subcutaneous inoculation of 2 ccm. 48 hr. agar slant culture, suspended 
 in 5ccm 0,85 % Nacl solution, causes illness in rabbits. A large abscess forms 
 at the site of inoculation, from which a vigorous and pigmentforming culture of 
 B. ruber indicus was isolated at the end of two weeks. Abscesses are also 
 formed by B. prodigiosus 1 and VII, B. rutilus (n. sp.) , and B. amylo- 
 ruber (n. sp.). Further investigations upon the pathogenicity as well as upon 
 the agglutinative properties of these organisms are in progress. 
 
30 
 
 by a high temperature without interfering with the luxuriance of 
 development. White light had a limiting, red light very little effect 
 upon the pigment; lack of oxygen and also pure oxygen were both 
 detrimental 1 ). Galeotti thus concluded 1) that the power of 
 chroinogenesis in bacteria is not connected indissolubly with the life 
 of those bacteria; such microorganisms may be able to live without 
 producing their characteristic pigment. 2) that the conditions of life 
 which affect the chromogenic power are generally those which have 
 an unfavorable influence upon the bacteria themselves in all their 
 functions. 3) that, given conditions unfavorable to the production 
 of pigment by any special chroraogenic microorganism, that organism 
 will, in a longer or shorter period of time, reacquire the power of 
 pigment production by adapting itself to the unfavorable conditions. 
 
 G a 1 e o 1 1 i ' s first conclusion is supported by most investigators 
 of bacterial chromogenesis, and by all the observations which are here 
 cited as to the ease with which the power of pigment production is 
 lost by some microorganisms. His second and third generalizations 
 are, however, debatable. 
 
 Noesske (18) says, speaking of B. pyocyaneus and 
 B. prodigiosus, "Nicht trotz, sondern infolge zu uppiger 
 Vegetationsbedingungen sistiert mauchmal die Farbstoffbildung auf 
 unserer gebrauchlichen Bouillon." Noesske is supported by 
 Wool ley (21), who concludes that B. pyocyaneus, B. jan- 
 thinus, and B. prodigiosus show better development but less 
 pigment in sugar media as compared with sugar free media; pig- 
 ment is produced more easily in 1 / than in 2 / sugar media, 
 with the exception of B. prodigiosus, which is alike in both 
 cases, but better in glucose than in lactose or saccharose. 
 
 The presence of sugar in nutritive media was, according to 
 Wasserzug, detrimental to the pigment production of B. pro- 
 digiosus; but Laurent (57) found that the influence of sugar 
 could be counteracted by the addition of alkali, i. e., that the in- 
 jurious effect was only indirect, through the acid formed from the 
 sugar by the bacteria. 
 
 Although no very definite conclusions can be drawn from media 
 containing so many unknown elements as our ordinary bouillon or 
 agar, a few preliminary experiments were made with agar as to the 
 effect following on the elimination of some of its constituents. Cul- 
 tures which had been 4 months on neutral sugar -free agar were 
 transferred to similar fresh agar slant tubes. After rejuvenation by 
 the bouillon, gelatin, and agar plate method, sugar -free and 1 
 
 1) cf. Pfeffer, W. Ber. der Kgl. Sachs. Gesellsch. d. Wissensch. Leipzig, 
 math.-phys. Klasse. 1896, p. 379, re Baumgartens Jahresb. 1896, p. 705. 
 ,,Farbstoffbildende Bakterien verraogen den Sauerstoff locker zu binden (ahnlich 
 wie das Hamoglobin) und ihn im sauerstofffreien Raum wieder abzugeben. Der 
 Trager dieser Erscheinung ist der Farbstoff, der die gleiche Wirkung auch iso- 
 liert im alkoholischen Extrakt zeigt, wahrend bei farblosen Bakterien em Gleiches 
 noch nie beobachtet ist. Die Farbstoffbildung, die bisher mehr als eine Luxus- 
 produktion erscheint, erscheint hiernach vieljeicht in einem fiir die Art un- 
 gleich zweckmassigeren Sinne, indem sie vielleicht die Bedeutung hat, dem betr. 
 Bakterium eine stete bereite Sauerstoffreserve zu sichern." 
 
31 - 
 
 dextrose agar slant tubes were inoculated from the same colonies, 
 with the following results: 
 
 Table III. 
 
 
 5 days, 
 
 Rejuvenated 
 
 
 Sugar-free 
 neutral 
 
 24 hrs. 
 
 24 hrs. 
 
 5 days 
 
 5 days 
 
 
 agar, after 4 
 months on 
 
 Sugar- 
 free 
 
 Glucose 
 
 Sugar- 
 tree 
 
 Glucose 
 
 
 neutr. agar 
 
 agar 
 
 agar 
 
 agar 
 
 agar 
 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 B. prodigiosus I 
 
 lux. 
 
 red 
 
 lux.' deep 
 
 lux. 
 
 pink, 
 
 lux. 
 
 red 
 
 lux. 
 
 red and 
 
 
 
 
 
 pink 
 
 
 trace 
 
 
 
 
 white 
 
 B. ruber indicus I 
 
 
 
 pins 
 
 
 
 
 
 
 
 
 
 
 
 pink, 
 
 >> 
 
 pink and 
 
 
 
 
 
 
 
 
 trace 
 
 
 white 
 
 B. II 
 
 
 
 - 
 
 
 
 n 
 
 n 
 
 
 
 >' 
 
 pink, 
 
 
 
 pink and 
 
 
 
 
 
 
 
 
 
 trace 
 
 
 white 
 
 B. ruber balticus 
 
 
 
 orange 
 
 1 7J 
 
 
 
 pink, 
 
 orange 
 
 >> 
 
 red at 
 
 
 
 red 
 
 
 
 trace 
 
 
 red 
 
 
 top 1 ) 
 
 B. ruber plym. I 
 
 ?j 
 
 pink 
 
 J> 
 
 pink 
 
 >j 
 
 red, 
 
 thin 
 
 red, 
 
 
 
 violet red, 
 
 
 
 
 
 trace 
 
 
 luster, 
 
 
 trace 
 
 
 lustre 
 
 B. ruber miquel 
 
 
 
 red 
 
 thin 
 
 orange 
 red 
 
 
 
 pink 
 
 
 
 orange 
 
 
 
 violet red 
 
 B. rutilus (n. sp.) 
 
 
 
 pink 
 
 5> 
 
 red 
 
 
 
 
 
 
 
 red 
 
 N 
 
 red and 
 
 
 
 
 
 
 
 
 
 
 
 white 
 
 B. amyloruber 
 
 wrink- 
 
 violet 
 
 j) 
 
 deep 
 
 ii 
 
 
 
 ft 
 
 violet 
 
 ,, 
 
 dark 
 
 (n. sp.) 
 
 led 
 
 red 
 
 
 pink 
 
 
 
 
 red 
 
 
 violet red 
 
 B. plym. II 
 
 lux. 
 
 pink 
 
 T) 
 
 
 
 j> 
 
 red, 
 
 n 
 
 
 
 
 
 red, luster 
 
 
 
 
 
 
 
 luster 
 
 
 
 
 
 B. kiliensis 
 
 
 
 red, 
 
 | 
 
 )J 
 
 
 
 
 
 red, 
 
 fair 
 
 
 
 J> 
 
 red, trace 
 
 
 
 trace 
 
 
 
 
 trace 
 
 
 
 
 
 B. miniaceus 
 
 >j 
 
 
 
 
 pink 
 
 
 red, 
 
 thin 
 
 pink, 
 
 >J 
 
 red, luster 
 
 
 
 
 
 trace 
 
 
 luster 
 
 
 trace 
 
 
 
 
 A comparison of the five-day sugar- free agar growth shows 
 B. plymouthensisl and B. rutilus' to have been apparently 
 greatly benefited by the rejuvenating process, B. kiliensis and 
 B. plymouthensis II as adversely affected, and the others as 
 not affected at all. This may be due in part to the fact that no 
 particular attempt was made to wait for colonies showing the 
 highest pigmentation, but only to inoculate both tubes from the 
 same colony. 
 
 When we compare the results of 24 hours for the two agars, 
 we find some interesting differences; the cultures are divisible at 
 once into two classes. B. prodigiosus I, B. ruber indicus I 
 and II, B. ruber balticus, B. ruber miquel, B. rutilus, and 
 B. amyloruber, all show more pigment on sugar free agar. With 
 the exception of B. ruber miquel, which was thin on sugar free 
 agar, the development was of about the same degree of luxuriance 
 on all. Three other cultures , B. plymouthensisl and II and 
 B. miniaceus, gave a surprising result in comparison with the others, 
 maximum pigmentation with green luster upon the sugar medium, 
 
 1) Later, more luxuriant and darker pigment on glucose agar. 
 
32 
 
 and very little or none at all upon the sugar free agar. B. kill en sis 
 is also of interest; it is a degenerate culture of feeble pigmentation, 
 and still shows a lingering tendency to return to normal if oppor- 
 tunity affords, i. e., upon a fresh transfer from an old culture, or 
 upon transference to a new (here a sugar) medium. 
 
 The five day growth presents the same differences, though less 
 distincfly. The mosaic appearance of B. ruber indicus and 
 B. rutilus is a beautiful expression of the existence of some pig- 
 ment-producing individuals among the mass of those not producing 
 pigment. This seems to argue that, here on solid media at least, 
 the presence of sugar has the effect not of modifying the pigment, 
 but of either permitting it unmodified or of inhibiting it. That the 
 acid formed from the sugar is the inhibiting influence may be ques- 
 tioned because of the early appearance of the differentiation. The 
 effect of acid directly upon the pigment may explain the more violet 
 red color of B. ruber miquel after five days, and the darker 
 color of B. a m y 1 o r u b e r. The 'late and luxuriant appearance of pig- 
 ment inB. ruberbalticuson sugar agar is a peculiar result entirely 
 inexplicable on the acid theory. It is to be noted that the three 
 cultures which produce early luxuriant pigment on sugar agar are 
 among those, of the whole series, which produce the most active fer- 
 mentation of sugars in the fermentation tube. 
 
 It seemed possible to obtain some light upon the question of 
 growth-luxuriance and pigment-luxuriance by eliminating the bouillon 
 from the ordinary agar medium. Accordingly a series was grown 
 upon agar 1,5 %, peptone 1 | , and water. This medium was first 
 tried of different reactions, 1,5 | acid, neutral, and 1,5 | alkaline 
 to phenolphthalein. The same medium, neutral, was used with the 
 addition severally of 1 | pure dextrose, lactose, and saccharose. 
 Two differences between the "meat-free" medium and the ordinary 
 nutrient agar were noticeable, though hardly measurable. The growth 
 is more limited, i. e., less spreading and "massy", and the pigment 
 is in general more intense in the former. Some of this depends, without 
 doubt, upon the vigor of the culture, a particularly vigorous strain being 
 able to overcome slight differences in the media, expressed, in feeble 
 strains like B. kiliensis, by a series showing distinct gradation. 
 
 (See Table IV p. 33.) 
 
 This 48 hour table brings out several points : 
 
 1) The tendency to violet red pigment on the more acid, to 
 orange red on the more alkaline media. 
 
 2) The similarity of pigment color on dextrose and saccharose 
 agar to that on sugar free agar of acid reaction. That is, acid is 
 probably formed from assimilation of these two sugars. 
 
 3) The similarity of pigment color on lactose agar to that formed 
 on sugar free neutral agar; i. e., lactose is probably not easily 
 assimilated. 
 
 This and the last named point seem to afford evidence of the 
 activity of sucrase but not of lactase. 
 
33 
 Table IV. 
 
 48 hours. 
 
 1,5 
 Gr. 
 
 Agar 1 
 Pigm. 
 
 r\ 01 
 .,<J / 
 
 Gr. 
 
 Pept< 
 
 Pigm. 
 
 Dne 1 
 1,5 
 Gr. 
 
 Pigm 
 
 Agar 1 
 1 L Dex. 
 Gr.|Pigra. 
 
 ,5 %, Peptone 1 
 1 % Lact. |1 % 
 Gr. |Pigm. Gr. 
 
 7, 
 
 Sacch. 
 Pigm. 
 
 B. prod. I 
 
 + + 
 
 violet 
 
 _l_ 
 
 violet 
 
 si. 
 
 
 
 + 
 
 violet 
 
 + 
 
 red 
 
 + 
 
 violet 
 
 
 
 red 
 
 
 red 
 
 
 
 
 red 
 
 
 + 
 
 
 red 
 
 B. II 
 
 + + 
 
 violet 
 
 + 
 
 violet 
 
 si. 
 
 
 
 + + 
 
 violet 
 
 + 
 
 orang 
 
 + 
 
 violet 
 
 
 
 red 
 
 
 red 
 
 
 
 
 red 
 
 
 red 
 
 
 red 
 
 B. III 
 
 ++ 
 
 violet 
 red 
 
 + 
 
 violet 
 red 
 
 si. 
 
 
 
 ++ 
 
 violet 
 red 
 
 + 
 
 r r| g 
 
 + 
 
 violet 
 red 
 
 B. IV 
 
 + + 
 
 red 
 
 + + 
 
 ver- 
 
 _J__I_ 
 
 ver- 
 
 + + 
 
 dalrk 
 
 + + 
 
 orang 
 
 + + 
 
 dark 
 
 
 
 + + 
 
 
 milion 
 
 
 milion 
 
 
 red 
 
 
 re? 
 
 
 red 
 
 
 
 
 
 + + 
 
 
 + 
 
 
 luster 
 
 
 luster 
 
 
 luster 
 
 B. V 
 
 + + 
 
 red 
 
 + 
 
 red 
 
 si. 
 
 si. 
 
 + 
 
 violet 
 red 
 
 + 
 
 orang 
 
 + 
 
 violet 
 red 
 
 B. VI 
 
 + + 
 
 violet 
 
 + 
 
 red 
 
 + 
 
 red 
 
 + 
 
 violet 
 
 + + 
 
 orang 
 
 + + 
 
 dark 
 
 
 
 red 
 
 
 + 
 
 
 + 
 
 
 red 
 
 
 red 
 
 
 violet 
 
 
 
 luster 
 
 
 
 
 
 
 + 
 
 
 + + 
 
 
 red 
 
 
 
 
 
 
 
 
 
 
 
 
 
 lustre 
 
 B. VII 
 
 + + 
 
 ver- 
 
 + + 
 
 ver- 
 
 + + 
 
 ver- 
 
 + + 
 
 violet 
 
 + + 
 
 orang 
 
 _!__!_ 
 
 violet 
 
 
 
 milion 
 
 
 milion 
 
 
 milion 
 
 
 red 
 
 
 red 
 
 
 red 
 
 
 
 + + 
 
 
 + + 
 
 
 + + 
 
 
 lustre 
 
 
 + + 
 
 
 lustre 
 
 B. VIII 
 
 _l- 
 
 violet 
 
 4. 
 
 violet 
 
 _j_ 
 
 violet 
 
 _^. 
 
 violet 
 
 4. 
 
 violet 
 
 _l_ 
 
 violet 
 
 
 
 red 
 
 
 red 
 
 
 red 
 
 
 + 
 
 
 
 
 + 
 
 B. r. ind. I 
 
 & 
 
 orange 
 red 
 
 dry 
 
 orange 
 red 
 
 dry 
 
 orange 
 red 
 
 
 dark 
 red 
 
 dry 
 
 orange 
 
 dry 
 
 orange 
 red 
 
 B. II 
 
 + + 
 
 orange 
 
 r 
 
 orange 
 
 
 pale 
 
 + 
 
 dark 
 
 + 
 
 orange 
 
 + 
 
 orange 
 
 
 dry 
 
 red 
 
 dry 
 
 red 
 
 dry 
 
 orange 
 
 
 red 
 
 
 j 
 red 
 
 
 red 
 
 
 
 -j- 4. 
 
 
 _(- 
 
 
 red 
 
 
 4. 4. 
 
 
 ii 
 
 
 _l_ 4. 
 
 
 
 luster 
 
 
 
 
 
 
 
 
 
 
 
 B. r. bait. 
 
 f -f 
 
 orange 
 
 4- 
 
 orange 
 
 4- 
 
 
 
 + + 
 
 violet 
 
 .f 
 
 orange 
 
 
 dark 
 
 
 
 red 
 
 
 red 
 
 
 
 
 red 
 
 
 red 
 
 
 red 
 
 
 
 + + 
 
 
 + 
 
 
 
 
 luster 
 
 
 + 
 
 
 + + 
 
 B. r. miquel 
 
 4- 
 
 red 
 
 sl. 
 
 
 
 4- 
 
 
 
 4. 
 
 dark 
 
 4. 
 
 
 
 4. 
 
 dark 
 
 
 
 + 
 
 
 
 
 
 
 red 
 
 
 
 
 red 
 
 B. r. ply. I 
 
 sl. 
 
 
 
 si. 
 
 
 
 si. 
 
 
 
 + + 
 
 dark 
 
 + 
 
 pink 
 
 + + 
 
 dark 
 
 
 
 
 
 
 
 
 
 red 
 
 
 
 
 red 
 
 
 
 
 
 
 
 
 
 duster 
 
 
 
 
 luster 
 
 B. rutilus 
 
 [-4- 
 
 violet 
 
 4. 
 
 red 
 
 si. 
 
 orange 
 
 + 
 
 
 
 _l_ 
 
 orange 
 
 _}_ 
 
 violet 
 
 
 
 red 
 
 
 + 
 
 + 
 
 red 
 
 
 
 
 red 
 
 
 red 
 
 B. amylo- 
 ruber 
 
 ++ 
 
 violet 
 red 
 
 ++ 
 
 red 
 
 + 
 
 orange 
 
 si. 
 
 pale 
 violet 
 
 + 
 
 violet 
 red 
 
 ++ 
 
 violet 
 red 
 
 
 
 _j__|_ 
 
 
 
 
 si. 
 
 
 
 
 _j_ 
 
 
 _i_i_ 
 
 B. ply. II 
 
 [- + 
 
 
 
 -|- 
 
 
 
 4. 
 
 
 .4. 
 
 dots 
 
 + + 
 
 
 
 r + 
 
 dots 
 
 
 
 
 
 
 
 
 
 red 
 
 
 
 
 red 
 
 B. kiliensis 
 
 + 
 
 deep 
 pink 
 
 + 
 
 pale 
 pink 
 
 + 
 
 ~ 
 
 + + 
 
 dark 
 red 
 
 + + 
 
 ~ 
 
 + + 
 
 pink 
 
- 34 
 
 4) The orange red color of B. ruber iudicus I and II on 
 acid agar is probably due to alkali-production. Query: - - Is the 
 large amount of acid formed byB. ruber indicus in bouillon and 
 on ordinary meat agar, as evinced by its better growth on alkaline 
 meat agar. a result of the meat albumins? 
 
 5) The range of color in B. amyloruber, as follows: 
 
 Red Orange Blue 
 
 1,5 / acid 87 10 3 
 
 Saccharose 70 20 10 
 
 Dextrose 50 30 20 
 
 Neutral and Lactose 65 15 20 
 
 1,5 % alkaline 45 55 
 
 6) the inhibition of pigment by dextrose in the case of B. ru- 
 tilus, although the saccharose tube shows evidence of assimilation, 
 i. e., is like 1,5 / acid. 
 
 After five days' growth some of these cultures were slightly less 
 characteristic, as would naturally result from the constantly increasing 
 complexity of the metabolic products. For example, B. pro- 
 digiosus IV had become vermilion on 1,5 % acid agar, no doubt 
 as a result of the alkali produced by the vigorously growing culture. 
 Other of the more slowly developing cultures bore out the results 
 of the first 48 hours, e. g., B. prodigiosus I IV had produced 
 orange red pigment on 1,5 alkaline agar, and B. plymouthen- 
 sis I slight violet red color on acid agar. Metallic green luster 
 had appeared for several cultures, noticeably for B. ruber balti- 
 cus on 1,5 % acid agar, and for B. plymouthensis I and II 
 on dextrose and on saccharose agar. Orange red color had 
 changed to red on lactose agar for B. prodigiosus V and for 
 B. rutilus, but excepting these and the colorless lactose agar cul- 
 tures of B. ruber miquel and B. plym. II, the orange tone still 
 held for the series on this medium, i. e., the alkali produced by the 
 bacteria was not neutralized by acid formed from the sugar. It 
 would seem that since B. ruber balticus, B. plymouthensis I, 
 and B. miniaceus ferment lactose with gas production, these cul- 
 tures would show a decrease of the orange tone. 
 
 Although the relative results arrived at on the above media are 
 of some value, their absolute value is lessened because of the 
 unknown factors present in agar and peptone. Agar itself contains 
 a certain amount of carbohydrate, galactose (Bauer, Jour. Prakt. 
 Chemie, B. XXX. p. 367), which is probably assimilable by the organisms. 
 A further reduction of the medium, by leaving out the peptone, 
 resulted in very feeble white growth in five days. Three cultures 
 only showed a trace of pigment, B. ruber indicus II, 
 B. rutilus, and B. prodigiosus VII. The last named showed 
 a green iridescence on the thin pink layer. 
 
 In the endeavor to do away with agar and still have a solid 
 medium for pigment production, the following mixtures were employed, 
 and gave interesting comparative results. The flour and starch were 
 cooked, poured into Petri dishes, sterilized by discontinuous method, 
 and inoculated. 
 
- 35 
 
 Table V. 
 
 
 Eice flour 35 %, 
 
 Starch 10 %, 
 
 Starch 10/ , 
 
 
 Pept. 1 /., 
 
 Pept. 1 %, 
 
 water 
 
 
 water 
 
 water 
 
 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 B. prodigiosus I 
 
 good 
 
 red 
 
 good 
 
 red 
 
 slight 
 
 slight, 
 
 
 
 
 
 
 
 pink 
 
 B. ruber balticus 
 
 fair 
 
 dark red 
 
 luxuriant 
 
 intense 
 
 thin 
 
 pink 
 
 B. kiliensis 
 
 good 
 
 red 
 
 spreading 
 good 
 
 red luster 
 red 
 
 spreading 
 
 n 
 
 pink 
 
 B. ruber miquel 
 
 fair 
 
 red 
 
 luxuriant 
 
 violet red 
 
 slight 
 
 red 
 
 B. rutilus (n. sp.) 
 
 good 
 
 dark red 
 
 
 
 cream 
 
 
 
 
 
 
 
 
 
 white 
 
 
 
 B. amyloruber 
 
 good 
 
 violet red 
 
 luxuriant 
 
 intense 
 
 spreading 
 
 pink 
 
 (n. sp.) 
 
 
 
 spreading 
 
 violet red 
 
 
 
 
 
 
 
 luster 
 
 
 
 Rice flour, which gave luxuriant growth when used with bouillon 
 by Schneider (19) and P e t r o w (58), gives good pigment, but rather 
 a thin dry layer, when bouillon is omitted. 
 
 The similarity between B. ruber balticus and B. kiliensis 
 was brought out by their development on starch and water. On 
 the other hand B. prodigiosus, B. ruber miquel, and 
 B. rutilus scarcely developed at all on cooked starch, but with the 
 addition of 1 % peptone gave a luxuriant growth. B. rutilus was 
 peculiar here in its absence of pigment, while B. amyloruber for 
 the first time produced, in addition to its usual vivid dark red color, 
 a distinct green metallic luster. The development of this organism 
 was evidently at its height of luxuriance on the starch-peptone 
 medium. Considerable liquefaction of the solid starch also took 
 place, an evidence of the production of a diastatic ferment by 
 B. amyloruber. After two weeks the semi-solid mass on this 
 plate was rubbed up in distilled water, filtered germ free and tested. 
 12 ccm peptonized 5 ccm of 10 % gelatin and water in two hours 
 at 37 C. A half inch cube of 10 % cooked starch was not liquefied 
 by the filtrate in 24 hours at 37 C, and I am unable to adduce 
 any evidence, other than that of the first observation, for the presence 
 of diastase. Fermi (22), and G o r i n i (41) report negative results as 
 regards diastatic ferments from B. prodigiosus and "B. ruber". 
 
 c. Growth and pigment in non-proteid media. 
 
 The value of the above experiments as to the affect of sugars 
 could only be tested by their repetition with non-proteid media, 
 where all the elements which go to make up the nutritive supply of 
 the organisms are definitely known. The only investigations of this 
 sort hitherto undertaken for red chromogenic forms have been upon 
 B. prodigiosus and B. kiliensis. Those upon the latter orga- 
 nism, by Laurent (57), were carried out mainly to test the effect 
 of acid in the medium, and led Laurent to the conclusion that an 
 alkaline reaction was most favorable to growth and pigmentation. But 
 
36 
 
 since in every case Laurent used media which contained either 
 saccharose or glycerine, and in which the initial alkaline reaction 
 had only the effect of neutralizing the acid produced by the organism 
 from these substances, his results prove nothing definite as to the 
 reaction best for non-fermentable media. As, also, the results of 
 Kuntze (46), Noesske (18), Luckhardt (16), and Sulli- 
 yan (20) upon B. prodigiosus in non-proteid media have dis- 
 agreed, the following tables of experiments on the Prodigiosus 
 series will be of interest 1 ). 
 
 Table VI. 
 
 
 Sol. A. 
 
 Sol. B. 
 
 Sol. C. 
 
 Sol. D. 
 
 Sol. E. 
 
 Sol. F. 
 
 
 
 
 
 
 
 Asp. 
 
 
 
 
 
 
 
 0,2 / 
 
 
 Asp. 0,2 o/o 
 MgSO 0,lo/o 
 KjHP0 4 0,lo/ 
 
 Asp. 
 0,2 o/o 
 KHP0 4 
 
 0,1 o/o 
 
 Asp. 
 
 0,2% 
 MgS0 4 
 
 Asp. 
 0,2% 
 
 Asp. 1,0 / 
 MgSO, 0,1 % 
 <HP0 4 0,lo/ 
 
 K ^ 
 
 
 
 
 
 
 
 Glycerine 
 
 
 
 
 
 
 
 2,0 % 
 
 
 Or. Pigm. 
 
 Or 
 
 Pigm. 
 
 Or. 
 
 Pigm. 
 
 Gr. |PIgm. 
 
 Or. 
 
 Pigm. 
 
 Gr. |pigm. 
 
 B. prod. I 
 
 
 
 
 
 
 
 
 
 
 
 15 
 
 days 
 
 
 -j- -}- 
 
 
 
 -f 
 
 
 
 
 
 
 
 
 
 
 
 ~H~i~ 
 
 5 da. 
 
 ~\~ ~\~ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 tr. 
 
 
 
 B. II 
 
 4.4. 
 
 
 
 -f 
 
 
 
 
 
 
 
 
 
 
 
 + + 
 
 5 da. 
 
 _j__j_ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 tr. 
 
 
 
 B. III 
 
 + + 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 + + 
 
 5 da. 
 
 + 4- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 tr. 
 
 
 
 B. IV 
 
 + -|_ 
 
 
 
 4- 
 
 
 
 
 
 
 
 
 
 
 
 + + 
 
 
 + + 
 
 
 
 B. V 
 
 _|__{- 
 
 
 
 
 
 
 
 
 
 
 
 
 + + 
 
 
 
 _j_ i 
 
 
 
 B. VI 
 
 _!__{_ 
 
 
 
 _^_ 
 
 
 
 
 
 __ 
 
 
 
 ii 
 
 
 
 ii 
 
 
 
 B. VII 
 
 + + 
 
 48 hrs. 
 
 + 
 
 48 hrs. 
 
 
 
 
 
 
 
 + + 
 
 48 hrs. 
 
 + + 
 
 
 
 
 
 3da.+ + 
 
 
 + 
 
 
 
 
 
 f 
 3da.+ + 
 
 
 
 B. VIII 
 
 + + 
 
 
 
 -- 
 
 
 
 
 
 
 
 
 
 
 6 da. 
 
 + + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 tr. 
 
 
 
 B. rub. ind. I 
 
 + 
 
 48 hrs. 
 
 + 
 
 + + 
 
 + 
 
 + + 
 
 +tr. 
 
 + + 
 
 + + 
 
 
 + + 
 
 
 
 
 
 3da.+ + 
 
 
 
 
 
 
 
 
 
 
 
 B. 11 
 
 + 
 
 48 hrs. 
 
 4- 
 
 -f + 
 
 + 
 
 + 4- 
 
 +tr. 
 
 _}._}- 
 
 + 
 
 48 hrs. 
 
 + + 
 
 
 
 
 
 ~T~ 
 
 
 
 
 
 
 
 
 4- 
 
 
 
 
 3da.+ + 
 
 
 
 
 
 
 
 
 
 
 
 B. rub. bait. 
 
 
 
 
 -f 
 
 
 
 
 
 
 
 
 
 
 
 + + 
 
 3 da. 
 
 + + 
 
 
 
 B. plym.I 
 B. .. miquel 
 
 + + 
 
 - 
 
 - 
 
 -r 
 
 
 
 +sl. 
 
 
 
 
 
 
 
 +_ + 
 
 -f si. 
 
 + + 
 
 si. 
 
 B. rutil. (n. sp.) 
 
 -j_ 
 
 
 
 _|- 
 
 
 
 -j-gl. 
 
 
 
 
 
 
 
 ii 
 
 
 _l__i_ 
 
 
 
 B. amylo- 
 ruber (n. sp.j 
 B. plym. II 
 
 + + 
 
 15 days 
 
 -r 
 
 
 +8l. 
 
 ^-~ 
 
 +? 
 
 ~~ 
 
 si. 
 
 15 days 
 
 
 
 
 1) The water used in these solutions was redistilled in glass. The inocu- 
 lations were made in flasks of Jena glass previously cleaned in acid and rinsed 
 repeatedly in distilled water. The reaction was neutral to phenolphthalein. 
 
JW 
 
 37 \ ' 
 
 These series bring out interesting results in the behavior of the 
 cultures. In standard aspafagin solution (Sol. A), B. prodigiosus I, 
 tested five times, and B. prod. II VI and VIII, tested twice, grew 
 luxuriantly, i. e., showed dense white cloudiness, but showed no trace 
 of pigment. B. ruber balticus, B. plymouthensis I and 
 II and B. r u t i 1 u s gave the same results , except that B. 
 rutilus developed less cloudiness. On the other hand B. prod. 
 VII, B. ruber indicus I and II, B. ruber miquel, and 
 B. amyloruber produced a good red coloration of the medium, 
 but none grew luxuriantly, except B. ruber miquel and B. 
 prod. VII. 
 
 In the next series (Sol. B), MgS0 4 was eliminated from the 
 medium in an attempt to determine whether this substance be neces- 
 sary for the elaboration of red bacterial pigment, as has been shown 
 for the fluorescent pigment. Nearly all the cultures developed, 
 although less readily than in Sol. A; three of them, B. ruber 
 indicus I and II, and B. prodigiosus VII, although showing 
 scarcely any cloudiness, colored the solution a beautiful red in 
 48 hours. With these three cultures which gave pigment in the 
 absence of MgSO 4 further tests were made. A pure 0,2 / solution 
 of asparagin was prepared, and flasks were inoculated by touching 
 the surface of an agar plate colony with a fine needle, or from a 
 growth in Sol. B. In each case B. ruber indicus I and II produced 
 no distinguishable cloudiness of the solution, but slowly and gradually 
 colored it as deep a red as they did the standard solution. B. pro- 
 digiosus VII failed to show pigment here, and control cultures of 
 B. ruber balticus and B. ruber miquel also remained perfectly 
 clear and colorless. 
 
 These results point toward one of two conclusions. Either the 
 pigment of some cultures of what is here designated as the Prod i- 
 giosus group has a different chemical basis from that of others of 
 the group, or on the other hand, great variation occurs among these 
 cultures in their ability to elaborate the same pigment out of the 
 same synthetic material. The results of chemical and spectroscopic 
 analysis of the pigments of B. prodigiosus, B. ruber balticus, 
 and B. ruber indicus (19), (45), (49) give us no reason to believe that 
 they are essentially different. Further, the fact that some cultures 
 do not produce pigment in a 0,2% asparagin solution even in the 
 presence of MgS0 4 , while others beside B. ruber indicus have 
 this power, indicates a continuous, rather than a discontinuous variation 
 of the ability to elaborate pigment. Whatever the cause of this may 
 be, it appears from my results to the present time that the different 
 strains or varieties are very constant in their ability or non-ability 
 to form pigment in the above solutions, whether the latter be in- 
 oculated from young or old cultures on various media. 
 
 In his work on B. prodigiosus, Kuntze used 12 % 
 asparagin and 0,1 0,2 / K 2 HP0 4 , obtaining pigment if MgS0 4 were 
 added in smallest crystals. In order to determine whether lack of 
 pigmentation in my series was due to an insuffiency of the organic 
 compound, I increased the asparagin content to 1 %. The first trial 
 
38 
 
 added B. ruber balticus only to the list of color producers. A 
 second set of flasks was inoculated from five day potato cultures, 
 with the result that B. prod. I III developed a slight trace of 
 pigment. Growth was most luxuriant for all the cultures in this 
 solution, but on the other hand B. ruber indicus I lost its power 
 of producing color by the concentration of the medium. 
 
 Standard asparagin solution with the addition of 2,0 / glycerine 
 allowed luxuriant growth, but of the whole series B. plymouthensisl 
 only showed a slight trace of pigment. 
 
 It seems evident from these experiments that the conclusions 
 drawn by Kuntze and Noesske regarding the necessity of MgS0 4 
 for pigment formation, and of phosphorus for growth, in the case of 
 B. prodigiosus, do not hold for all of the various strains going 
 under this name. Out of eight strains three did not form pigment 
 even under these conditions, although all were cultures in the height 
 of vigor; one culture produced pigment in the absence of one, and 
 two strains of a closely related form in the absence of both the 
 above substances. 
 
 The more luxuriant development of some of the non-pigmented 
 cultures in comparison with the slighter growth of other colored ones, 
 notably B. ruber indicus, seems to confirm the statement made 
 by Noesske and quoted previously in this paper. Further light 
 upon the subject of correlation of chromogenesis and growth, as well 
 as upon the effect of the presence of carbohydrate in the nutritive 
 medium, was obtained by the following experiments. 
 
 Table VII. 
 
 
 Sol. fl. 
 
 Sol. I 
 
 Sol. K 
 
 
 Asp. 0,2 % 
 MgSO A 0,1 % 
 
 Dextrose l'o/ 
 
 Asp. 0,2% 
 MgSO 4 0,1 % 
 K,HP0 4 0,1% 
 Lactose 1,0% 
 
 Asp. 0,2% 
 MgS0 4 0,1% 
 K 2 fiP0 4 0,1 % 
 Saccharose 1,0% 
 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 (ir. 
 
 Pigm. 
 
 B. prod. I. 
 
 4-4- 
 
 tr. 4 da. 
 
 4-4- 
 
 
 
 + + 
 
 
 
 B. prod. II 
 
 4-4- 
 
 tr. 8 da. 
 
 4-4- 
 
 
 
 + + 
 
 
 
 B. prod. Ill 
 
 .j_.|- 
 
 tr. 3 da. 
 
 _j_ _). 
 
 
 
 4- + 
 
 tr. 3 da. 
 
 B. prod. IV 
 
 + + 
 
 4 da. 
 
 + + 
 
 
 
 + 4- 
 
 
 
 
 
 + 15 da. 
 
 
 
 
 
 B. prod. V 
 
 + + 
 
 + tr. 3 da. 
 
 + + 
 
 
 
 + + 
 
 4- tr. 3 da. 
 
 
 
 tr. 15 da. 
 
 
 
 
 
 B. prod. VI 
 
 _l__j_ 
 
 tr. 8 da. 
 
 + + 
 
 
 
 4-4- 
 
 + 8 da. 
 
 B. prod. VII 
 
 4-4- 
 
 + tr. 4 da. 
 
 + + 
 
 + 3 da. 
 
 _l__j_ 
 
 + 4 da. 
 
 
 
 + + 15 da 
 
 
 + tr. 15 da. 
 
 
 + +15 da. 
 
 B. prod. VIII 
 
 + + 
 
 + tr. 4 da 
 
 + + 
 
 
 + + 
 
 + tr. 8 da. 
 
 B. rub. ind. I 
 
 _^._j_ 
 
 
 
 ^_ 
 
 + 4- 
 
 _l__^. 
 
 
 
 B. rub. ind. II 
 
 _j__^_ 
 
 + 8 da. 
 
 ^. 
 
 
 _l__j_ 
 
 
 
 B. rub. bait. 
 
 4-4- 
 
 + 3 da. 
 
 + + 
 
 
 
 4-4- 
 
 + tr. 
 
 B. rub. pty. I 
 
 + + 
 
 
 si. 
 
 
 
 _^_^_ 
 
 + 
 
 B. rub. miquel 
 
 + + 
 
 + 3 da. 
 
 si. 
 
 + 4 da. 
 
 + + 
 
 + 
 
 
 
 
 
 + + 8 da. 
 
 
 
 B. rutilus (n. sp.) 
 
 4. _|_ 
 
 + 8 da. 
 
 ,|_ 
 
 
 + 4- 
 
 
 
 B. amyloruber (n. sp.) 
 
 ++ 
 
 
 + 
 
 + 
 
 + 4- 
 
 
 
 B. plym. II 
 
 4-+ 
 
 
 
 + + 
 
 
 
 + + 
 
 
 
- 39 - 
 
 When this table is compared with Table VI the similarity of 
 results with Sol. E and Sol. H is at once noticeable, the presence 
 of dextrose producing much the same effect as the concentration of 
 the medium by increasing the asparagin content. \Vith the addition 
 of dextrose to a standard asparagin solution, growth is luxuriant in 
 all cases, but although there is an increase of pigment production 
 over Sol. A, where in most cases there was none at all, still the 
 amount of pigment for B. prod. I VI and VIII is at most only 
 a trace. On the other hand, B. prod. VII shows a development of 
 pigment, which at the end of fifteen days is as strong as in the 
 standard solution in three days; and B. ruber indicus I and II 
 show, as in Sol. E, more luxuriant growth with a lessening of pigment 
 production. 
 
 Comparing the effect of the different carbohydrates, we see that 
 saccharose behaves on the whole like dextrose, although in some 
 cases the pigment failed to appear in Sol. K, where it did appear 
 in Sol. H. Lactose gives quite different results. In fact, Sol. I con- 
 taining lactose behaves exactly like Sol. A with no carbohydrates, 
 i. e. pigment is produced with B. prod. VII, B. ruber indicus I 
 and II, B. ruber miquel and B. amyloruber only, these, with 
 the exception of B. prod. VII, showing less luxuriant growth than 
 the rest of the series. This seems an exceedingly interesting result, 
 and falls in line with the conclusion drawn from Table IV, where the 
 color of the pigment gave evidence of the peculiar lack of effect of 
 the presence of lactose. 
 
 It is difficult, even here, to arrive at any general conclusion in 
 regard to the relation of growth luxuriance and pigment luxuriance. 
 As has just been stated, the majority of the cultures showing pigment 
 in Sol. I have grown less luxuriantly than the others. The same 
 thing was true with Sol. A. Again, B. ruber indicus I and II 
 tended to lose entirely their power to form pigment when the growth 
 luxuriance was increased by concentrating the medium or by adding 
 glycerine or sugar. 
 
 These facts, taken in connection with that of less massy growth 
 and more vivid pigment on peptone agar as against the more com- 
 plex meat peptone agar, seem to argue in confirmation of Noesske's 
 and Wool ley's views. On the other hand, Sol. H, in which dextrose 
 induces luxuriant growth, shows pigment, though only traces of it, in 
 fourteen cases, against four cases in Sol. A without dextrose. It may 
 be that here the sugar contributes chemical or physiological aid to 
 pigment formation as well as to vegetative luxuriance. The contrary 
 effect of glycerine points to this conclusion, since here we have 
 luxuriant growth without pigment. 
 
 In this connection also, some of the atypical cultures which have 
 virtually lost the power of forming pigment are interesting. Both 
 B. fuchsinus and B. miniaceus III are among the most 
 vigorous strains of the series in rapidity and amount of development. 
 The latter and B. kiliensis, although colorless, have lost none 
 of their vigor in the fermentation of sugar to gas formation, or in the 
 
40 
 
 liquefaction of gelatin or coagulation of milk. These facts do not 
 support, then, Galeotti's second conclusion, that the conditions of 
 life which affect the chromogenic power are generally those which 
 have an unfavorable influence upon the bacteria themselves in all their 
 functions. 
 
 d) The effect of light upon pigment production. 
 
 Following the methods of Buchner and of Marshall Ward, 
 Dieudonn6 (13) confirmed the simpler experiments ofGaleotti (15) 
 regarding the effect of light upon bacterial chromogenesis. He used 
 B. prodigiosus and B. fluorescens, and found that the direct 
 sunlight of March, July, and August hindered development in 
 half an hour, while 48 hours of exposure entirely prevented pigmen- 
 tation and trimethylamine production. B. prodigiosus also lique- 
 fied gelatin more feebly. Eleven hours of incandescent electric light 
 killed both organisms. According to Dieud onus's investigations, 
 these effects were produced by the light and not by the heat rays, 
 the violet and ultra violet rays being the destructive agents, and the 
 red and yellow rays having no effect. The injury is chiefly to the 
 germs themselves, the chemical change produced in the medium being 
 a very small factor. Similar results were obtained with B. c o 1 i , 
 B. typhosus, and B. anthracis, confirming those of Ward, who, 
 however, limits the injurious effect to the violet end of the blue, the 
 actinic rays. 
 
 Beck and Schultz (14) criticised Dieudonn6's methods, and 
 observed no injury to the development of B. prodigiosus, B. 
 pyocyaneus etc., from exposure to colored light, though in some 
 cases there was an influence upon chromogenesis (2 3 days). Diffuse 
 daylight was beneficial, darkness sometimes proving injurious, 
 (Staphyl. pyog. aureus and B. fluorescens). Direct sunlight 
 (3 days) produced colorless cultures. 
 
 The results of Beck and Schultz do not seem very conclusive; 
 the non-effect of the colored light may have been due to the slight 
 intensity of the rays which passed through their light filters. In a 
 recent paper Oliver (17) used colored glass plates. 
 
 A simple comparative study as to the effect of direct sunlight 
 upon a series of my organisms gave the following results. One loop- 
 ful-inoculations were made upon slant agar from 18 hour bouillon 
 cultures which had been grown in the dark ; these were used as 
 controls. The cloudy bouillon cultures were then exposed to the 
 March sunlight (according toDieudonnd as effective as that of 
 July), and similar agar slant cultures inoculated at intervals. These 
 agar cultures were then grown in the dark and examined after 24 hours, 
 48 hours, and ten days. The results are appended. 
 
41 
 
 Table VIII. 
 
 
 24 hours' growth after exposure to sun of 
 
 
 min. 
 
 5 min. 
 
 15 min. 
 
 30 min. 
 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 Gr. 
 
 Pigm. 
 
 fe. prod. I 
 B. niberbalt. 
 3. ruber miq. 
 
 + + 
 
 E 
 
 dotted 
 
 
 
 dotted 
 
 
 
 dotted 
 
 
 
 5. rutilus (n. sp.) 
 5. amylor. (n. sp.) 
 B. rosac. metali. 
 
 w 
 
 si. 
 
 + -f 
 
 
 
 tt 
 
 
 
 
 
 
 
 prod. I 
 5. niberbalt. 
 S. ruber miq. 
 J. rutilus (n. sp.) 
 5. amylor. (n. sp.) 
 5. rosac. metali. 
 
 + + 
 + 4- 
 + + 
 4- + 
 
 48 hours' growth after exposure to sun 
 
 - red 
 
 _l_ 
 
 pink 
 
 _l_ 
 
 pink 
 
 - red 
 
 4- + 
 
 pink 
 
 -1-4- 
 
 4- pink 
 
 --red 
 - red 
 
 + + 
 
 orange red 
 4- slight red 
 
 + + 
 
 orange red 
 pink 
 
 - red 
 
 mge 
 
 + + + 
 
 + +red 
 
 *J+ 
 
 + 4-+ red 
 
 pink 
 pink 
 pink 
 pink 
 f red 
 
 10 days' growth after exposure to sun 
 
 J. prod. I 
 
 4- + 
 
 + 4- red 
 
 thin 
 
 pink 
 
 thin 
 
 piuk 
 
 thin 
 
 pink 
 
 5. ruber bait. 
 3. ruber miq. 
 
 + + 
 
 + + red 
 + + red 
 
 thin 
 
 pink 
 
 + 4- red 
 
 thin 
 
 pink 
 
 + red 
 
 thin 
 
 pink 
 + dull red 
 
 5. rutilus (n. sp.) 
 
 _l__l_ 
 
 + + red 
 
 thin 
 
 pink 
 
 thin 
 
 pink 
 
 thin 
 
 pink 
 
 $. amylor. (n. sp.) 
 
 4.+ 
 
 + + dark red 
 
 -j--j- 
 
 4- + dark red 
 
 4--|- 
 
 + 4- dark red 
 
 -1-4- 
 
 4- + dark rec 
 
 5. rosac. metali. 
 
 4-4- 
 
 + + orange 
 
 + + 
 
 + 4- orange 
 
 -f 
 
 4- 
 
 thin 
 
 pale 
 
 prod. I 
 ruber bait, 
 ruber miq. 
 rutilus (n. sp.) 
 amylor. (n. sp.) 
 rosac. metali. 
 
 48 hours after 2 hours exposure to sun. 
 Growth normal, pigment faint pink 
 
 thin, faint pink 
 
 very slight, slight 
 
 normal, faint pink 
 
 thinner normal 
 
 no development 
 
 From the tables it will be seen that the 24 hour cultures pre- 
 sented a curious developmental result. The cultures of B. ruber 
 balticus which had been made after 30 minutes' exposure to the 
 sun showed more development than the control, while the other 
 exposures exhibited a comparative decrease of effect, a 5 minutes' 
 exposure giving less growth than one of 15 minutes. Greater 
 development of a 15 minutes' exposure as compared with one of 
 5 minutes was also shown by B. prodigiosus, B. ruber miquel, 
 and B. amyloruber, so that the possibility of an accidental 
 mechanical error, e. g., the transference of a loopful of germs crowded 
 at one side of the tube by heliotaxis, was excluded from consideration. 
 The experiment was repeated for B. ruber balticus, B. 
 rutilus, and B. amyloruber with the same results. 
 
 A possible explanation of the phenomenon may be suggested. 
 Gotschlich (5) has remarked that brief exposure of a culture to 
 an injurious influence may react beneficially to the culture as a whole, 
 by cutting out the weaker organisms, and leaving only the u Aus- 
 nahmezellen" ; that is, that there may be selective death-rate. On this 
 
42 
 
 supposition the first effect of the sunlight was the destruction of a 
 great number of the less resistant organisms, which accounts for the 
 slighter mass-development of the cultures after the 5 minute exposure. 
 For the remaining and more resistant cells we must then assume that 
 the actinic effect of a 15 minute exposure was stimulating, promo- 
 ting cell division, somewhat as exposure to increased osmotic pres- 
 sure 1 ) or to lack of oxygen, to heat, etc., induces it in unfertilized 
 parthogenetic eggs. As the eggs in these experiments must be 
 exposed only briefly and then returned to their normal environment 
 if maximal results are to be obtained, so with the bacterial cells. 
 The accelerating effect of the sunlight on growth does not seem to 
 be an enduring one, for later observations upon the same cultures 
 show that development is in reality permanently hindered; as much, 
 in the case of B. prodigiosus, B. ruber balticus, and B. 
 rutilus, by 5 minutes' exposure as by one of 30 minutes, and 
 nearly as much by 5 minutes as by one of 2 hours. 
 
 The pigmentation of B. amyloruber and B. ruber balticus 
 also showed, in the 48 hour agar culture, a distinctly better color 
 after the 15 minute exposure. The chromogenesis of the others of 
 the series was markedly decreased by a 5 minute exposure, and only 
 B. ruber miquel showed any recovery after ten days. The greater 
 resistance of B. amyloruber, which was as brilliantly pigmented 
 after two hours' exposure to the sun as at first, was probably due to 
 its recent isolation from river water. 
 
 No attempt was made to determine the further history of these 
 cultures. 
 
 4. Summary. 
 
 The experimental and comparative work done on these cul- 
 tures of pigment bacteria may be roughly summarized as follows: 
 
 1) Notwithstanding the occasional loss of power of pigment 
 production by a previously chromogenic organism, the character of 
 the pigment is markedly constant among red chromogenic bacteria. 
 By constancy is here understood the appearance of pigment of definite 
 color upon nutritive media of known composition and under defined 
 environmental conditions. 
 
 2) A collection of about forty red cultures selected at random 
 fell readily into four main groups, according to slight but constant 
 differences in the character of the pigment as determined by a 
 standard color scale. 
 
 3) Sports, or discontinuous variations, such as white or light 
 colored colonies on a plate, viscosity of growth etc. sometimes oc- 
 cur. In general however the socalled important biological characters 
 are not subject to discontinuous variation. 
 
 1) Loeb, J., Further Experiments on Artificial Parthenogenesis and the 
 Nature of the Process of Fertilization. (Amer. Jour, of Physiol. IV. 1900. p. 178.) 
 Matthews, A. P,, Some Ways of Causing Mitotic Division in Unfertilized 
 Arbacia Eggs. (Amer. Jour, of Physiol. IV. 1900. p. 343.) 
 
43 
 
 4) Considerable nonnal variation in biological characters is 
 seen among the members of the Pro digios us group on ordinary 
 media. In many cases this does not exceed the variations shown 
 by a series of inoculations made from the same culture. It was 
 noticeable that although gas production varied for most of these 
 organisms, the ratio of C0 8 to the total gas remained comparatively 
 constant. 
 
 5) Within comparatively narrow limits the pigment color of the 
 Prodigiosus group may be altered by changing the composition 
 of the nutritive medium. 
 
 6) Also by variation in the composition of the nutritive medium, 
 cultures usually distinct from one another in pigment character can 
 be made to approximate, e. g. to change from orange to violet 
 red; or to assume pigment qualities previously foreign to them, 
 e. g. metallic luster. The former characters are regained upon 
 transference to the original medium. 
 
 7) There is a tendency to violet red pigment in more acid, to 
 orange red in more alkaline media. 
 
 8) Dextrose and saccharose in peptone agar medium favor 
 pigment formation much more than does lactose. 
 
 9) The ability or non-ability to produce pigment in non-proteid 
 media is a particularly constant character for each of the different 
 members of the Prodigiosus group; but strains which are 
 otherwise approximate in biological characters may differ in this 
 ability. 
 
 10) Two strains in the Prodigiosus group, viz. B. ruber 
 in die us I and II, differed from all the others in the ability to 
 produce pigment in pure asparagin solution, without MgS0 4 or 
 K 2 HP0 4 . 
 
 11) The effect upon pigment production of adding dextrose and 
 saccharose to a standard asparagin solution is similar to that of 
 concentrating the solution by increase of asparagin content. Here 
 again, lactose is shown to be without effect upon pigment. 
 
 12) There is probably little or no correlation between luxuriance 
 or vigor and the power of pigment formation. Hence pigment 
 production does not appear to be essential to the life-processes of 
 an organism. 
 
 I). Notes on Groups of Bed Chromosome Bacilli. 
 
 The division into groups of the pigment bacteria by means of 
 the color scale falls in closely with the division according to other 
 biological characters as shown by the species description table. 
 Aside from the differentiation made in the discussion of pigment 
 production above, the inter-relationship of the members of some 
 groups may be briefly described as follows: 
 
44 
 
 I. The Prodigiosus group. 
 
 A. Gelatin liquefied. 
 
 1. No gas in dextrose, lactose, or saccharose. 
 
 B. prod. VIII, B. amyloruber, B. fuchsinus. 
 
 2. Gas in dextrose only. 
 B. prod. I, II, III. 
 
 3. Gas in dextrose and saccharose only. 
 
 B. prod. IV, VI, VII, B. ruber indicus I, II, 
 B. rutilus. 
 
 4. Gas in dextrose, lactose and saccharose. 
 
 B. prod. V, B. plymouth ensis, B. miniaceus, B. 
 kilien sis. 
 
 B. Gelatin not liquefied. 
 
 1. Gas in dextrose only. 
 B. ruber miquel. 
 
 n. The Lactis erythrogenes group. 
 
 The members of this group are characterized by the production 
 of soluble red pigment. The appended table shows also some inter- 
 mediary forms described by Dyar (loc. cit.). 
 
 
 
 
 1 
 
 Sol. red. pig. 
 
 Insol. pig. 
 
 Gel. liq. 
 
 Agar gr. 
 
 Milk 
 
 Gr. at 
 
 37V, 
 
 1)B. lactis ery. I 
 
 _ 
 
 agar, gel. and milk 
 
 yellow 
 
 + 
 
 lux. soft 
 
 coag. alk. 
 
 _ 
 
 2) II 
 
 - 
 
 n j> 
 
 pale yel. 
 
 + 
 
 1 
 
 
 
 
 
 3) B. ery. rugat. 
 
 
 
 
 
 
 
 
 Dyar 
 
 
 
 (Dyar) 
 
 yellow 
 
 + 
 
 folded 
 
 
 
 
 
 4) B. helvolus 
 
 
 
 
 
 
 
 
 Zimm. 
 
 
 
 n 
 
 
 
 + slowly 
 
 lux. soft 
 
 
 
 ? 
 
 5) B. granul. 
 
 
 
 
 
 
 
 
 Dyar g 
 6) B. rubefaciens 
 
 + 
 
 gel. and agar 
 
 pale yel. 
 yellowish 
 
 + 
 
 granular 
 smooth 
 
 coag. acid. 
 
 ? 
 
 
 
 
 in gel. 
 
 
 
 
 
 7) B. lactorubef. 
 
 + 
 
 + milk 
 
 white 
 
 
 
 > 
 
 
 
 
 
 8) B. rutilescens 
 
 + 
 
 gel. and agar 
 
 
 
 + 
 
 lux. 
 
 j> 
 
 + 
 
 
 
 
 
 
 smooth 
 
 
 
 A culture from Krdl of B. ros e oflu or esc ens Tataroff, 
 which is said by Migula to be identical with B. lactis ery- 
 throgenes, was evidently atypical, showing thin white growth 
 and no pigment. It was non-motile, non-liquefying, and had no 
 effect upon milk. 
 
 III. The Rubricus group. 
 
 These cultures were of interest because they are typical forms 
 of a group of red chromogenic organisms quite different from the 
 Prodigiosus group. I have no doubt that the whole series of 
 small and non-motile, non-liquefying, slow growing red forms, i. e. 
 
45 
 
 distinct from B. ruber miquel, are much more closely related 
 than the members of the P r o d i g i o s u s group , if they are not 
 all identical. This includes forms isolated and described by 
 Dyar, B. zeta, B. delta, B. ferruginous, B. salmoneus, 
 B. rhodocrous Overbeck, B. finitimus ruber, B. haema- 
 t o i d e s Wright etc. Some of these are recorded as liquefying 
 gelatin slowly or very slowly. The pigment ranged from salmon 
 pink and orange to red. Milk is either unchanged or alkaline. 
 
 I desire to express my grateful thanks to -Professor Edwin 
 O.Jordan, of the University of Chicago, under whose advice and 
 direction the work embodied in "this paper was carried out 
 (See Table IX p. 4647, Table X p. 4851.) 
 
 Bibliography 1 ). 
 General. 
 
 1) Chester, F. D., Manual of determinative bacteriology. New York 1901. 
 
 2) E is en berg, J., Bakteriologische Diagnostik. Hamburg und Leipzig 1891. 
 
 3) Fliigge, C., Die Mikroorganismen. Leipzig 1896. 
 
 4) Fraenkel, C., Grundrifi der Bakterien kunde. Berlin 1894. 
 
 5) Kolle, W. and Wassermann, A., Handbuch der pathogenen Mikro- 
 organismen. Jena 1902. 
 
 6) La far, F., Technical Mycology, transl. Salter. Vol. I. Lond9u 1898. 
 
 7) Lehmann, K. B. and Neumann, E. 0., Atlas and principles of bac- 
 teriology, ed. from the second German ed. by G. H. Weaver, Phila. and 
 London 1901. 
 
 8) Lustig, A., Diagnostik der Bakterien des Wassers. Jena 1893. 
 
 9) Mac, E., Traite pratique de bacte'riologie. Paris 1891. 
 
 10) Migula, W., System der Bakterien. Bd. II. Jena 1900. 
 
 11) Steinberg, G. M., Manual of bacteriology. New York 1892. 
 
 12) Zimmermann, O. E. E. , Die Bakterien unserer Trink- und Nutzwasser. 
 Chemnitz. I und II. 1890. III. 1900. 
 
 13) Dieudonne*, A., Beitrage zur Beurteilung der Einwirkung des Lichtes auf 
 Bakterien. (Arb. aus dem Kaiserl. Gesundheitsamte. Bd. IX. Wien 1894. 
 p. 405. (cf. full bibliography there given). 
 
 13a) , Beitrage zur Kenntnis der Anpassungsfahigkeit der Bakterien an ur- 
 spriinglich ungiinstige Temperaturverhaltnisse. Ib. 1894. p. 492. (with biblio- 
 graphy). 
 
 14) Beck, M. und Schultz, P., Ueber die Einwirkung sogenannten mono- 
 chromatischen Lichtes auf die Bakterienentwickelung. (Zeitschr. f. Hyg. 
 Bd. XXIII. 1896. p. 490.) 
 
 15) Galeotti, G. , Eicherche biologiche sopra alcuni batteri cromogeni. (Lo 
 Sperimentale. VoL XLVI. 1892. Fasc. 3. p. 261.) 
 
 16) Luckhardt, A. E., Ueber Variabilitat und Bedingungen der Farbstoff- 
 bildung bei Spaltpilzen. Diss. Freiburg 1901. 
 
 17) Oliver, C. A., An experimental study of the effects of change of color 
 upon pigment-bacteria, (Amer. Journ. Med. Sci. Vol. CXXIII. 1902. p. 647.) 
 
 18) Noesske, H., Versuche iiber die Bedingungen der Farbstoffbildung des 
 Bacillus pyocyaneus. (Beitr. z. klin. Chirurg. Bd. XVIII. Tubingen 1897. 
 p. 103.) 
 
 19) Schneider, P., Die Bedeutung der Bakterienfarbstoffe fur die Unter- 
 scheidung der Arten. Diss. Basel 1894. (Arb. d. bakt. Inst. Karlsruhe. 1895. 
 Abdr. im Centralbl. f. Bakt. Bd. XVI. p. 633.) 
 
 20) Sullivan, M. X., The chemistry of bacterial pigments. (Abstr. im CentralbL 
 f. Bakt, Bd. X. 1903. p. 386.) 
 
 1) Articles not seen by the writer are bracketed [ ], and the place from 
 which the reference was obtained is subjoined. 
 
46 
 
 
 
 
 Bio 
 
 
 
 Morphology 
 
 Cultural Features 
 
 Name of Organism 
 
 Source 
 
 . . 
 
 
 Nutrient 
 broth tube 
 
 Nutrient 
 agar tube 
 
 Gelatine 
 plate 
 
 Gelatine 
 stab 
 
 Potato tube 
 
 Fermentatioa 
 tube 
 
 bi 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -^ 
 
 
 
 
 
 
 
 , &,* 
 
 
 & 
 
 ^ 
 
 
 ^j 
 
 2 a 
 
 
 
 J3 
 
 gjM 
 
 o 
 
 1 
 
 
 & 
 
 
 1 
 
 i o3 o 
 
 I 
 
 1 
 
 G 
 
 
 
 
 
 i-s 
 
 
 
 1 
 
 i| 
 
 I 
 
 I 
 
 1 
 
 1 
 
 d 
 
 _g 
 
 K^ 
 
 J'-| | 5 
 
 i 
 
 
 
 -c 
 
 25 
 
 I 
 
 O QQ 
 
 
 
 ^^ 
 
 3"^ 
 
 
 "" 
 
 H 
 
 P 
 
 B! 
 
 
 
 i 
 
 i 
 
 1 > 
 
 H 
 
 o-l 
 
 B. prodigiosus I, II, 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 III 
 
 
 -f- 
 
 
 
 ~~ 
 
 
 
 
 
 4- 
 
 
 
 
 
 -(- 
 
 4* 
 
 .:- 
 
 _(- 
 
 4- 
 
 4- 
 
 4- 
 
 B. prodigiosus IV, 
 VI, Vft 
 
 
 4- 
 
 
 
 + 
 
 
 
 
 
 4- 
 
 
 
 
 
 + 
 
 + 
 
 f 
 
 + 
 
 4- 
 
 4- 
 
 4- 
 
 B. prodigiosus V 
 
 
 4- 
 
 
 
 + 
 
 
 
 + 
 
 4- 
 
 
 
 
 
 + 
 
 
 
 -r 
 
 4- 
 
 4- 
 
 4- 
 
 4- 
 
 B. VIII 
 
 
 4- 
 
 
 
 4- 
 
 
 
 
 
 4- 
 
 
 
 
 
 _j- 
 
 
 
 4- 
 
 4- 
 
 4- 
 
 4- 
 
 4- 
 
 B. ruber indicus I, II 
 
 
 4- 
 
 
 
 
 
 
 4r 
 
 
 
 
 
 
 ^_ 
 
 _l_ 
 
 
 4- 
 
 4- 
 
 
 4- 
 
 B. ruber plymouth- 
 ensis I, ft, III 
 B. kiliensis, B. ruber 
 
 
 4- 
 
 
 
 4- 
 
 ^ 
 
 
 
 4- 
 
 
 
 
 
 * 
 
 + 
 
 + 
 
 
 4- 
 
 4- 
 
 4- 
 
 balticus 
 
 
 4- 
 
 
 
 4- 
 
 
 
 4- 
 
 4- 
 
 
 
 
 
 4- 
 
 4 
 
 4- 
 
 4- 
 
 4- 
 
 4- 
 
 4- 
 
 B. miniaceus I, II, III 
 
 
 + 
 
 
 
 + 
 
 _ 
 
 
 
 4- 
 
 
 
 _ 
 
 + 
 
 h 
 
 -1- 
 
 + 
 
 4- 
 
 4- 
 
 4- 
 
 B. rutilus (n. sp.) 
 
 
 4- 
 
 
 
 4- 
 
 
 
 
 4- 
 
 
 
 
 
 4- 
 
 
 
 
 4- 
 
 4- 
 
 4- 
 
 B. amyloruber (n. sp.) 
 
 
 4- 
 
 
 
 4- 
 
 . 
 
 
 
 4- 
 
 
 
 
 
 + 
 
 + 
 
 + 
 
 + 
 
 4- 
 
 4- 
 
 4- 
 
 B. fucnsinus 
 
 
 4- 
 
 
 
 4- 
 
 
 
 -- 
 
 4- 
 
 
 
 
 4- 
 
 4 
 
 4 
 
 -r 
 
 4- 
 
 4- 
 
 4- 
 
 B. ruber miquel 
 
 
 4- 
 
 
 
 
 
 
 
 -r 
 
 4- 
 
 
 
 
 
 4- 
 
 
 + 
 
 -r 
 
 4- 
 
 4- 
 
 4- 
 
 B. rubricus (n. sp.) 
 
 
 4- 
 
 
 
 __ 
 
 
 
 4- 
 
 4- 
 
 
 
 
 
 + 
 
 
 
 + 
 
 _ 
 
 
 
 
 
 
 
 B. rufus (n. sp.) 
 
 
 4- 
 
 
 
 
 
 4- 
 
 -t- 
 
 
 
 
 
 _l_ 
 
 
 
 -r 
 
 __ 
 
 
 4- 
 
 
 
 B. ruber zimmermann 
 
 
 
 
 
 + 
 
 
 4- 
 
 
 
 
 
 
 
 _l_ 
 
 
 
 
 , __ 
 
 4- 
 
 
 
 
 B. havaniensis 
 
 
 4- 
 
 
 
 
 
 - 
 
 4- 
 
 
 
 
 
 
 
 + 
 
 ' 
 
 4- 
 
 
 
 
 
 
 
 
 B. lactis erythrogenes 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 I, II 
 
 
 4- 
 
 
 
 -- 
 
 
 
 4- 
 
 4- 
 
 
 
 
 
 4- 
 
 - 
 
 4- 
 
 h 
 
 4- 
 
 4- 
 
 4- 
 
 B. rubefaciens 
 
 
 4- 
 
 
 
 4- 
 
 
 4- 
 
 4- 
 
 
 
 
 
 4- 
 
 - 
 
 - 
 
 r 
 
 4- 
 
 4- 
 
 4- 
 
 B. lactorubefaciens 
 
 
 4- 
 
 
 
 + 
 
 
 4- 
 
 4- 
 
 
 
 
 
 4- 
 
 - 
 
 ; 
 
 4- 
 
 4- 
 
 4- 
 
 4- 
 
 B. rutilescens (n. sp.) 
 
 
 4- 
 
 _ 
 
 4- 
 
 _ 
 
 4- 
 
 4- 
 
 _ 
 
 _ 
 
 + 
 
 _ 
 
 + 
 
 4- 
 
 4- 
 
 4- 
 
 + 
 
 B. mycoides roseus 
 B. mycoides coral- 
 
 
 4- 
 
 
 
 
 
 4- 
 
 
 ; 
 
 4- 
 
 + 
 
 
 
 ' r 
 
 4* 
 
 4- 
 
 4- 
 
 
 
 linus (n. sp.) 
 B. latericeus (?) 
 
 
 4- 
 
 i 
 
 - 
 
 
 4- 
 4- 
 
 4- 
 
 4- 
 
 ~ 
 
 J 
 
 J 
 
 -r 
 
 
 
 r 
 
 4- 
 
 4- 
 
 4- 
 4- 
 
 
 
 B. rubro pertinctus 
 B.rosaceus metalloides 
 
 
 4- 
 
 
 
 - 
 
 
 4- 
 
 4- 
 
 -i- 
 
 4- 
 
 
 
 -t- 
 
 F* 
 
 
 ' 
 
 4- 
 
 i 
 
 4- 
 4- 
 
 4- 
 
 
 
 B. mesentericus ru- 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 ber, 1-IV 
 
 
 r 
 
 
 
 -r 
 
 
 4- 
 
 
 
 
 
 4- 
 
 
 
 4- 
 
 4- 
 
 4- 
 
 4- 
 
 
 
- 47 - 
 
 IX. 
 
 logy 
 
 Biochemical Features 
 
 Pathogenesis 
 
 SL : 3 : 1 
 
 > ~ is 
 
 = r c8 
 
 Liquefaction Gas production 
 
 Milk 
 
 Nutrient agar tubes 
 
 Mice 
 
 A 
 
 precip 
 
 lus 
 
 4- 
 
 lus 
 
 4- 
 
 lus 
 
 Lus rare 
 hts 
 
 lus 
 lus 
 
 + 
 + 
 
 sweet 
 
 red 
 red 
 
 red 
 red 
 
- 48 
 
 Table 
 
 
 
 
 Bio 
 
 
 
 Morphology 
 
 Cultural Features 
 
 
 
 
 
 
 
 
 
 Nutrient 
 broth tube 
 
 Nutrient 
 agar tube 
 
 Gelatine 
 plate 
 
 Gelatine 
 stab 
 
 Potato tube 
 
 Fermentation 
 tube 
 
 Name of Organism 
 
 Source 
 
 
 
 
 
 
 
 
 
 fc 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 "i :L 
 
 
 
 
 
 
 
 
 
 1> 
 
 o| 
 
 
 
 ? 
 
 | 
 
 
 -g 
 
 .2 
 
 
 
 =3 
 
 ^a 
 
 1 
 
 ~ 
 
 2 
 
 12 
 
 
 a 
 
 11 
 
 i 
 
 
 1 
 
 -S 
 IS 
 
 
 
 ll 
 
 
 
 - 
 
 1^ 
 
 
 -j~ 
 
 1 
 
 1 
 
 13 
 Q 
 
 1 
 
 S * 
 
 1 
 
 ! 
 
 5 
 
 I 
 
 g 
 
 1 
 
 1^ 
 
 B. rubidus (Eisenberg) 
 B. ruber aquatilis 
 
 
 + 
 
 
 
 4- 
 
 
 
 + 
 
 + 
 
 
 
 
 
 + 
 
 --. 
 
 + 
 
 + 
 
 + 
 
 
 
 + 
 
 (Lustig) 
 
 water 
 
 -j- 
 
 
 
 - 
 
 
 
 j_ 
 
 
 
 
 
 _i_ 
 
 _;_ 
 
 4_ 
 
 i 
 
 1 
 
 
 
 
 B. sardinae (Du Bois 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 St. Se"vrin) 
 
 
 4- 
 
 
 
 f- 
 
 
 + 
 
 4- 
 
 
 
 
 
 + 
 
 + 
 
 -r 
 
 4- 
 
 4- 
 
 4- 
 
 
 B. carneus (Tils) 
 
 
 + 
 
 
 
 + 
 
 
 
 
 
 _ 
 
 _ 
 
 + 
 
 + 
 
 + 
 
 _^ 
 
 _l_ 
 
 + 
 
 
 B. ruber Berolinensis 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (Fraenkel) 
 
 water 
 
 4- 
 
 
 
 _l_ 
 
 
 
 
 
 __ 
 
 __ 
 
 _j_ 
 
 
 j 
 
 _ L 
 
 t 
 
 _j. 
 
 
 B. sulfureus (Holz- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 schewnikoff, 
 
 
 -f 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B. subfulvus (Matzu- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 schita). B. tuberi- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 genus 4, (Gonner- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 mann) 
 
 
 _j- 
 
 
 j. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B. pneumonicus agi- 
 lis (Schon) 
 
 
 + 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B. viguali (Matzu- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 schita) (B. Vigual) 
 
 
 -f 
 
 
 ~ 
 
 
 
 _l_ 
 
 _j_ 
 
 
 
 _J_ 
 
 
 _;_ 
 
 
 _l_ 
 
 red 
 
 
 B. liquefaciens com- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 munis (Stern berg) 
 
 
 4- 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -f 
 
 
 
 B. pyocinnabareus 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 wrinkl. 
 red 
 
 
 
 (Ferchmin) 
 
 pus 
 
 -r 
 
 
 
 
 
 __ 
 
 i 
 
 i 
 
 
 
 _ 
 
 _i_ 
 
 i 
 
 i 
 
 i 
 
 
 red 
 
 
 B. The've'nm 
 
 pus 
 
 4- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B. ruber lactis (Conn) 
 B. rubiginosus (Keru) 
 B. tuberosus (Kern) 
 
 milk 
 
 4- 
 
 
 
 
 
 
 
 
 
 + 
 
 
 
 + 
 
 + 
 
 + 
 
 + 
 
 
 + 
 
 
 
 
 + 
 
 + 
 
 
 
 B. rubescens (Zim- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 mermann) 
 
 
 -\- 
 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 _i_ 
 
 
 
 _j_ 
 
 ! 
 
 dry 
 
 
 
 B. velatus (Matzu- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 J 
 
 
 
 schita) 
 
 
 4- 
 
 
 
 
 
 
 
 
 
 4- 
 
 
 
 
 \ 
 
 red 
 
 
 B. colere laterum 
 
 water 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B. exiguus (Wright) 
 B. haematoides 
 
 
 .^_ 
 
 
 
 
 
 
 
 
 + 
 
 
 
 
 
 
 + 
 
 
 
 
 
 
 (Wright) 
 
 B. epsilon (Dyar) 
 
 air 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 + 
 
 
 
 B. zeta (Dyar) 
 
 air 
 
 4- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B. delta (Dyar) 
 
 water 
 
 4- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 + 
 
 
 
 
 B. ferruginous (Dyar) 
 B. finii inm-i ruber 
 
 air 
 
 -i 
 
 
 
 
 
 
 
 
 + 
 
 
 
 + 
 
 
 
 
 
 
 
 (Dyar; 
 
 
 _l_ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B. salmoneus (Dyar) 
 
 
 4- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 49 - 
 
 X. 
 
 
 logy 
 
 Biochemical Features 
 
 Pathogenesis 
 
 
 
 6 
 
 Liquefaction 
 
 Gas prodaction 
 
 
 
 Milk 
 
 
 Nutrient agar tube 
 
 ! Mice 
 
 fs 
 
 1 
 
 if 
 
 
 
 i 
 
 I 
 
 1 
 
 a o 
 
 QQ 
 
 1 
 1 
 
 1 
 
 
 
 
 fe 
 
 CO 
 
 1 
 
 i 
 
 li 
 
 If 
 
 P 
 
 li 
 1 
 
 o 
 
 1 Gelatine 
 
 .a 
 
 a 
 
 1 
 
 | 
 
 1 
 
 1 
 
 1 
 
 55 
 
 1 
 
 I 
 
 5 
 
 1 
 
 i 
 
 I 
 
 8 
 
 1 
 
 II 
 
 si 
 
 a 
 
 
 
 + 
 
 -I- 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 brick 
 
 
 
 
 
 + 
 
 * 
 
 
 -f- 
 
 
 + 
 
 
 
 
 
 
 +? 
 
 H 
 
 ? 
 
 
 red 
 
 
 
 
 red 
 
 + 
 
 
 + 
 
 * 
 
 
 4- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 | 
 
 
 * 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 f 
 
 
 
 + 
 
 
 _i_ 
 
 
 
 
 
 
 _j_ 
 
 
 
 ^_ 
 
 
 
 
 
 red 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 + 
 
 | 
 
 
 + 
 
 + 
 
 
 
 
 
 
 
 + 
 
 
 + 
 
 
 pink 
 yellow 
 
 red 
 
 red 
 
 
 
 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 red 
 
 
 + 
 
 
 
 
 - 
 
 + 
 
 
 
 
 
 
 + 
 
 
 
 + 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 si. 
 
 
 
 
 
 
 
 
 
 
 - 
 
 ~ 
 
 ; 
 
 
 pink 
 
 
 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 + 
 
 + 
 
 
 
 red 
 
 
 
 pink 
 
 
 
 sL 
 
 
 
 
 
 
 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 4- 
 
 
 brick 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 reddish- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 pink 
 
 
 
 
 
 
 
 
 
 
 
 
 
 _i_ 
 
 
 
 
 
 
 salmon 
 
 
 
 
 
 
 
 
 
 
 
 
 Sl. 
 
 
 
 
 
 
 
 
 
50 - 
 
 Table X 
 
 
 
 
 Bio 
 
 
 
 Morphology 
 
 Cultural Features 
 
 Name of Organism 
 
 Source 
 
 
 Nutrient 
 hroth tube 
 
 Nutrient 
 agar tube 
 
 Gelatine 
 plate 
 
 Gelatine 
 stab 
 
 Potato tube 
 
 Fermentation 
 tube 
 
 
 i 
 
 
 
 
 
 
 
 
 
 - 
 
 ~ 
 
 
 jj 
 
 g 
 
 
 
 s 
 
 a 
 
 
 
 1 
 
 I 
 
 a 
 
 X 
 
 Q 
 1 
 
 1 
 1 
 
 Q 
 
 1 Wrinkled 
 
 Charac- 
 teristic app 
 ranee 
 
 5 
 p. 
 
 1 
 00 
 
 I 
 
 r 
 
 Luxurian 
 
 o 
 
 B. rhodochrous Over- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 beck (Dyar) 
 
 
 4_ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B. rubefaciens pyo- 
 genes (Matzuschita) 
 Bact. rubrum (Mi- 
 
 
 + 
 
 
 
 + 
 
 
 
 + 
 
 + 
 
 
 
 + 
 
 
 
 
 + 
 
 + 
 
 + 
 
 + 
 
 
 gula) 
 
 
 _;_ 
 
 _j_ 
 
 
 
 
 
 
 
 
 
 
 
 _^_ 
 
 
 
 
 
 
 
 Bact. erythromyxa 
 Zopf (Migula) 
 B. nibescens (Jordan) 
 
 
 + 
 
 
 
 
 
 
 
 
 + 
 
 
 
 
 
 + 
 
 
 
 
 + 
 
 
 
 
 Bact. carnosum 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (Kern) 
 
 
 j_ 
 
 
 
 
 
 
 
 _l_ 
 
 
 
 __ 
 
 
 
 
 
 
 
 _I_ 
 
 _j_ 
 
 
 
 
 Bact. roseum (Losski) 
 
 
 -j- 
 
 
 
 
 
 
 
 + 
 
 _|- 
 
 
 
 
 
 
 
 
 
 4. 
 
 -f 
 
 4- 
 
 rose 
 
 
 B. nitrogenes (Mat- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 zuschita) B. deni- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 trificans II, Burri 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 and Stutzer) 
 
 
 + 
 
 
 -r 
 
 
 
 _j_ 
 
 _^_ 
 
 
 
 
 _^_ 
 
 
 
 ^_ 
 
 _>_ 
 
 _|_ 
 
 _{_ 
 
 
 B. rubescens (Matzu- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 schita) (B. oogenes 
 hydrosulfureus j. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Zorkendorfer) 
 
 
 -f 
 
 
 
 _^_ 
 
 
 
 _l_ 
 
 
 
 
 
 
 
 
 
 
 ^. 
 
 _^_ 
 
 ^_ 
 
 ^. 
 
 
 B. subrubiginosus 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (Maschek) 
 
 
 >|. 
 
 
 _j_ 
 
 
 
 
 
 
 
 
 
 
 _j_ 
 
 
 
 B. lupini (Matzu- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 schita) 
 
 
 _j_ 
 
 
 i 
 
 
 
 
 
 
 
 
 
 
 _j_ 
 
 
 
 B. pseudomycoides 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (Migula) 
 B. coccineus (Pansini) 
 
 
 J 
 
 
 
 
 J 
 
 
 + 
 
 
 
 
 
 + 
 
 + 
 
 + 
 
 J 
 
 + 
 
 + 
 
 
 B. rubellus (Okada) 
 
 
 f 
 
 
 
 + 
 
 + 
 
 
 + 
 
 
 
 + 
 
 
 
 + 
 
 + 
 
 
 
 
 B. thermophilus 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 liquef. aerobiuB 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (Oprescu) 
 
 
 _|_ 
 
 
 
 
 _ 
 
 _l_ 
 
 !_ 
 
 
 
 
 
 
 
 _^. 
 
 _j_ 
 
 
 B. thermophilus 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 liquef. tyrogenes 
 (Oprescu) 
 
 
 + 
 
 
 
 4. 
 
 1 + 
 
 + 
 
 
 + 
 
 
 
 
 
 + 
 
 + 
 
 
 B. mycoides ruber 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (Matzuschita) 
 
 
 _|_ 
 
 
 -f 
 
 J. 
 
 
 
 
 
 
 
 
 
 4. 
 
 4- 
 
 
 B.Dan teci (LeDantec) 
 
 
 + 
 
 
 
 -f 
 
 
 
 
 
 
 
 
 
 _l_ 
 
 
 
 
 B. apicum (Cane- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 strini) 
 
 
 i 
 
 
 4_ 
 
 _l_ 
 
 
 
 
 
 
 
 
 
 -1- 
 
 
 
 B. rubiginosus (Ca- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 tiano) 
 
 
 _j_ 
 
 
 
 4- 
 
 _l_ 
 
 
 
 
 
 
 
 _j_ 
 
 
 
 r 
 
 -|- 
 
 _j_ 
 
 
 
 B. subcoccineus (Ca- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 tiano) 
 
 
 -;- 
 
 
 
 -f 
 
 _l_ 
 
 
 
 
 
 
 
 _j_ 
 
 _ 
 
 f 
 
 J. 
 
 _j_ 
 
 
 
 B. kermesinus (Ta- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 taroff) 
 
 
 -f 
 
 + 
 
 -i- 
 
 -f 
 
 
 _j_ 
 
 + 
 
 -|- 
 
 
 
 
 -f 
 
 
 + 
 
 
 
 
 B. rosaceus marga- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 rineua (Jolles and 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Winkler) 
 
 
 _|_ 
 
 __ 
 
 + 
 
 _l_ 
 
 
 
 
 
 
 
 ^_ 
 
 ._ 
 
 _(_ 
 
 _ _ 
 
 _l_ 
 
 -f 
 
 
 B. subrubeum (Kern) 
 
 
 -f 
 
 
 
 
 4- 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
continued. 
 
 - 51 
 
 logy 
 
 Biochemical Features 
 
 I Pathogenesis 
 
 h^ 
 
 
 I 
 
 Liquefaction 
 
 Gas production 
 
 
 
 Milk 
 
 
 Nutrient agar tubes 
 
 Mice 
 
 1 Grows at bod? 
 temperature 
 
 Facultative 
 anaerobe 
 
 I 
 
 | Gelatine 
 
 | 
 
 Blood serum 
 
 1 
 
 1 
 
 Saccharose 
 broth 
 
 1 Nitrate reduced 
 
 1 
 
 I 
 
 'o 
 c 
 
 1 
 
 1 
 
 3 
 
 Alkaline 
 
 5 
 
 'S 
 
 .2 
 1 
 
 Fluorescence 
 
 Intra-peritoneal 
 inoculation 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 pink 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 + 
 
 
 
 -r 
 
 
 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 red 
 
 
 
 + 
 
 
 
 
 _ 
 
 
 
 
 
 
 
 
 
 
 
 
 red 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 pink 
 
 
 
 
 + 
 
 
 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 flesh 
 
 red 
 
 
 + 
 
 
 
 ~ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 rose 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 red 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 reddish 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 red 
 
 
 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -}- 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 red 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 +55 
 
 + 
 
 
 + 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 + 
 
 + 
 
 
 
 red 
 
 
 
 + 
 
 + 
 
 
 I 
 
 + 
 
 + 
 
 
 
 
 
 
 
 
 + 
 
 
 
 
 red 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 path, for bees 
 
 + 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 red 
 
 
 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 4- 
 
 + 
 
 
 
 
 orange 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 red 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 rose 
 
 
 
- 52 
 
 21) Woolley, P. G., Experiments made to determine the effect of sugar upon 
 the pigment-formation of some chromogenic bacteria. (Johns Hopkins Bull. 
 
 Vol. X. 1899. p. 130.) 
 
 22) Fermi, GL, Die Leim- und Fibrin-losenden und die diastatischen Fermente 
 der Mikroorganismen. (Archiv f. Hygiene. Bd. X. p. 154.) 
 
 B. prodigiosus. 
 
 23) 1819. Bizio, B. [Gazzetta privilegiata di Venezia. Aug. 24.] Spica No. 44 
 below. 
 
 1823. [Bibliot. Ital. o sia Giorn. di letterat., scienze ed arti. Vol. XXX- 
 p. 275, Milano.l Spica No. 44 below. 
 
 24) 1844. See also id., Comptes rendus, Paris. Vol. XVIII. p. 951. 
 
 25) 1824. Sette [Memoria storico-naturale sull' arrossamento straordinario di 
 alcune sostanze ah'mentose. Venice]. Spica, ib. 
 
 26) 1839. Ehrenberg, Chr. G. [Monatsber. iiber die zur Bekanntmachung ge- 
 eigneten Verhandl. d. Kgl. preufl. Akad. der Wissenschaften, Berlin.] Migula. 
 
 27) 1850. Fresenius, G. [Beitrage zur Mykologie. Frankfurt a. M. 1850 bis 
 1863]. 
 
 28) 1866. Erdmann, O. Bildung von Anilinfarben aus Proteinkorpern. (Journ. 
 f. prakt. Chemie. Bd. III. p. 385.) 
 
 29) 1872. Schroeter, J., Ueber einige durch Bakterien gebildete Pigmente. 
 (Cohns Beitr. z. Biol. der Pflanzen. Bd. I. Heft 2. p. 109.) 
 
 30) 1872. Cohn, F., Untersuchungen iiber Bakterien. (Beitr. z. Biol. d. Pflanzen. 
 Bd. I. Heft 2. p. 127. See p. 151 ff., Ueber Pigmentbakterien.) 
 
 31) 1875. - [I. Heft 3. p. 142 ff.?J 
 
 32) 1875. Helm, O., Ueoer Monas prodigiosa und den von ihr erzeugten Farb- 
 stoff. (Archiv f. Pharmacie. Bd. III. p. 19.) 
 
 33) 1879. Wernich, A., Versuche iiber die Infektion mit Micr. prodigiosus. 
 (Cohns Beitr. z. Biol. d. Pflanzen. Bd. III. p. 105 (pubd. 1883). 
 
 34) 1886. Liborius, P., Beitrage zur Kenntnis des Sauerstoffbedurfnisses der 
 Bakterien. (Zeitschr. f. Hygiene. Bd. I. p. 115.) 
 
 35) 1887. Schottelius, M., Biologische Untersuchungen iiber den Micrococcus 
 prodigiosus. (Printed from Festschr. fur Koelliker. Leipzig. Abstr. in 
 Centralbl. f. Bakt. Bd. II. p. 439 (1887). 
 
 36) 1888. Strazza, G. Beitrage zur Lehre iiber die Biologic der Mikroorga- 
 nismen. (Wiener med. Jahrb. Heft 1.) 
 
 37) 1888. Wasserzug, E., Variations de forme chez les bacteries. (Ann. dePInst. 
 Past T. II. p. 75, 153.) 
 
 38) 1889. Kuebler, P., Ueber das Verhalten des Micr. prodigiosus in saurer 
 Fleischbriihe. (Centralbl. f. Bakt. Bd. V. p. 333.) 
 
 39) 1892. Griffiths, A. B. Sur la matiere colorante du Monas prodigiosa. 
 (Comptes rendus de 1' Academic de Science. T. CXV. p. 321.) 
 
 40) 1892. Gorini, C. [Studi experimentali sul latte. Roma.] (Abstr. in Centralbl. 
 f. Bakt. Bd. XII. p. 666.) 
 
 41) 1893. Das Prodigiosus-Labferment. (Hygien. Rundschau. Bd. III. p. 381.) 
 
 42) Bordoni-Uffreduzzi, G., Fall von fuchsinahnlicher Bakterienfarbung 
 des Fleisches. (Hygien. Rundschau. Bd. IV. p. 12.) 
 
 43) 1896. Scheurlen, E., Geschichtliche und experimentelle Studien iiber den 
 Prodigiosus. (Archiv f. Hygiene. Bd. XXVI. p. 1.) 
 
 44) 1899/1900. Spica, P., Sulla materia colorante prodotta dal Micrococcus 
 prodigiosus. (Kivendicazione di prioritd, per Bartolomeo Bizio.) (Atti del Reale 
 Istituto Veneto di scienze, lettere, ed arti. Vol. LIX. Parte seconda, dis- 
 perse 10. p. 10251031.) 
 
 45) 1899. Rosenberg, W. W., Beitrage zur Kenntnis der Bakterien farbstoffe, 
 insbes. der Gruppe des Bact. prodigiosum. Diss. Wiirzburg. 
 
 46) 1900. Kuntze, W., Ein Beitrag zur Kenntnis der Bedingungen der Farbstoff- 
 bildung des B. prodigiosus. (Zeitschr. f. Hygiene. Bd. XXXIV. p. 169.) 
 
 47) 1900. Ritter, G. Zur Physiologic des B. prodigiosus. (Centralbl. f. Bakt. 
 Bd. VI. p. 206.) 
 
 48) 1900. Marx, H., Die Pathogenitat des B. prodigiosus. Eine Bemerkung zur 
 Farbs toff prod uktion der Bakterien. (Archiv f. lain. Chirurgie. Bd. LXII. 
 p. 347.) 
 
53 
 
 49) 1902. Kraf t,E., Beitrage zur Biologic des B. prodigiosus und zum chemischen 
 Verhalten seines Pigments. Diss. Wiirzburg. 
 
 49a) 1903. Bertarelli, E., Untersuchungen und Beobachtungen iiber die Bio- 
 logie u. Pathogenitat des Bacillus prodigiosus. (Centralbl. f. Bakt. Bd. XXXI V. 
 p. 193.) 
 
 B. ruber indicus (Koch). 
 
 50) K o c h , R. f Berichte iiber die Reise zur Erforschung der Cholera. 1884.] M i gu 1 a. 
 
 51) Fraenkel, C., Grundrifl der Bakterienkunde. 1891. p. 229. 
 
 52) Fliigge, op. cit. as 3), p. 302. 
 
 53) Migula, op. cit. as 10), p. 306. 
 
 B. plymouthensis (Fischer). 
 
 54) Fischer, B. Bakteriologische Untersuohungen auf einer Reise nach West- 
 indien. (Zeitschr. f. Hygiene. Bd. II. 1887. p. 74.) 
 
 55) Voges, O. , Ueber einige im Wasser vorkommende Pigmentbakterien. 
 (Centralbl. f. Bakt. Bd. XIV. 1893. p. 314.) 
 
 B. ruber balti CUB \ (Breunig)> 
 B. ruber kiliensis / 
 
 56) Breunig, J. [Bakteriologische Untersuchung des Trinkwassers der Stadt 
 Kiel. Diss. Kiel, 1888.] Migula. 
 
 57) Laurent, E., Etude sur la variability' du bacille rouge de Kiel. (Ann. de 
 1'Inst. Pasteur. T. IV. 1890. p. 465.) 
 
 58) Petrow, N., Ueber einen neuen roten Farbstoff bildenden Bacillus. (B. sub- 
 kiliensis). (Arbeit des Bakt. Inst. der Grossh. Hochschule zu Karlsruhe, 1902. 
 p. 273.) 
 
 B. miniaceus (Zimmermann). 
 
 59) Zimmermann, op. cit. as 12), Reihe I. p. 46. 
 
 B. fuchsinus (Boekhout and de Vries). 
 
 60) Boekhout, F. W. J., und de Vries, J. J. Ott, Ueber einen neuen 
 chromogenen Bacillus. (Centralbl. f. Bakt. Bd. IV. 1898. p. 497.) 
 
 B. ruber (Zimmermann). 
 
 61) Zimmermann, O. E. R., op. cit. as 12), Reihe I. p. 24. 
 
 B. havaniensis (Sternberg). 
 
 62) IS tern berg, G. M., Manual of bacteriology. 1892. p. 718. 
 
 B. lactis erythrogenes (Hueppe). 
 
 63) Grotenfeldt, G., Studien iiber die Zersetzungen der Milch. (Fortschr. der 
 Med. Bd. VII. 1889. p. 41.) 
 
 64) Tatarof f [Die Dorpater Wasserbakterien. Diss. Dorpat, 1891. p. 21, p. 60?] 
 Migula. 
 
 65) Dyar, H., On certain bacteria from the air of New York City. (Ann. N. Y. 
 Acad. Sci. Vol. VIII. 1895. p. 324.) 
 
 66) Galeotti, G., see No. 15, ante. 
 
 B. rubefaciens (Zimmermann). 
 
 67) Zimmermann, op. cit. as 12), Reihe I, p. 26. 
 
 B. lactorubef aciens (Gruber). 
 
 68) Gruber, Th., Ueber einen die Milch rosa farbenden Bacillus. (Centralbl. f. 
 Bakt, Bd. VIII. 1902. p. 457.) 
 
 B. mycoides roseus (Scholl). 
 
 69) Grotenfeldt, loc. cit, p. 46. 
 
 70) Ei sen berg, op. cit. as 2), p. 84. 
 
 71; Migula, op. cit, p. 482 (B. mycoides)! 
 
 B. latericeus (Adametz). 
 
 72) Adametz, L., [Die Bakterien der Trink- und Nutzwasser. Mitteil. der osterr. 
 Versuchsst f. Brauerei u. Malzerei in Wien. Heft 1. 1888. p. 50.] Chester, 
 op. cit as 1), p. 173. 
 
 73) Dyar, loc. cit. as 65), p. 361. 
 
B. rubropertinc tu s. 
 
 74) Grass berger, R., Ueber die nacn intraperitonealer Injektion von Markt- 
 butter bei Meerschweinchen entstehenden Veranderungen. (Miinch. med. Woch. 
 1899. p. 343.) 
 
 B. mesentericus ruber (Globig). 
 
 75) Globig, Ueber einen Kartoffelbacillus mit ungewb'hnlich widerstandsfahigeu 
 Sporen. (Zeitschr. f. Hygiene. Bd. III. 1888. p. 323.) 
 
 B. rosaceus metalloid es (Tataroff). 
 
 76) Tataroff [Die Dorpater Wasserbakterien. Diss. Dorpat, 1891.] Migula. 
 
 77) Hefferan, Mary, An unusual bacterial grouping. (Centralbl. f. Bakt. 
 Bd. III. 1902. p. 689.) 
 
 Reference list of red chromogenic Bacteria. 
 
 (cf. Table X.) 
 
 B. rubidus Eisenberg. Bakt. Diagnostik, p. 88. 1891 
 
 B. ruber lactis (Conn). Rep. Conn. Agric. Sta. 1899 
 
 Bact. pyocinnabareum (Ferchmin. "red pus") Centralbl. f. Bakt. Bd. XIII. 
 
 p. 103. 1894 
 
 Bact. rubiginosum (Kern) Arb. d. techn. Hochschule zu Karlsruhe. Bd. I. 
 
 Heft 4. 1896 
 
 B. rubiginosus (Catiano). Cohns Beitrage. Bd. VII. p. 538. 1896 
 
 B. subcoccineus 539. 1896 
 
 B. coccineus (Pansini). Virchows Archiv. Bd. CXXI1. 
 
 p. 437 1890 
 
 B. sardinae (Du Bois St. Se'vrin). Ann. Past. T. VIII. p. 152. 1894 
 
 B. rubellus (Okada). Centralbl. f. Bakt. Bd. XI. p. 1. 1892 
 
 B. carneus (Tils). ' Zeitschr. f. Hyg. Bd. IX. p. 294. 1890 
 
 Bact. rubrum (Migula). Migula. p. 488. 1900 
 
 Bact. erythromyxa (Zopf). p. 487. 
 
 (Zopf himself (Ber. d. deutsch. botan. Gesellsch. 1891. p. 22) , calls his 
 
 form a micrococcus). 
 Bact. pseudomycoides (Migula). 
 
 Bact. carnosum (Kern) cf. Kern above also Migula. p. 485. 
 Bact. tuberosum (Kern) p. 490. 
 B. rubescens (Jordan). Rep. Mass. State Bd. of Health, p. 835. 1890 
 
 B. roseus (Fischer) Die Bakterien des Meeres. p. 22 1894 
 
 B. rubrofuscum (Fischer) p. 36 
 
 B. mesentericus roseus (Zimmermann). Zimmermann. II. p. 26 1890 
 
 See Lustig. p. 72. Name (Kruse) see Fliigge p. 303. 
 Bact. roseum (Losski). Die Mikroorganismen des Bodens. Diss. Dorpat. See 
 
 Migula, p. 484. 
 B. kermesinus (Tataroff). Die Dorpater Wasserbakterien. Diss. Dorpat. 1891 
 
 See Migula p. 858. 
 
 B. exiguum (Wright). Mem. Nat. Acad. Sci. Vol. VII. p. 447. 1895 
 
 B. haematoides (Wright). p. 448. 
 
 B. epsilon (Dyar). Ann. N. Y. Acad. Sci. Vol. VIII. p. 369. 1895 
 
 B. zeta - p. 369. 
 
 B. delta p. 368. 
 
 B. ferrugineus (Dyar) p. 361. 
 
 B. fimt iiniis ruber (Dyar) ,, p. 361. 
 
 B. salmoneus (Dyar) 
 B. rhodochrous (Overbeck. Dyar) 
 
 (Overbeck himself called the organism a micrococcus) 
 
 See his art., Nov. Act. Leop. Carol. Acad. Vol. LV. D. 16. 1891 
 
 B. ruber berolinensis (Fraenkel, p. 252) Fliigge. Die Mikroorganismen. 
 
 p. 303. 1896 
 
 B. sulfureus (Holzschewnikoff). Fortschr. d. Med. Bd. VII. p. 201. 1889 
 
 B. subfulvus (Matzuschita) = "B. tuberigenus 4", Gonnermann, Landw. 
 
 Jahrb. Bd. XXIII. p. 656. 1894 
 
 B. velatus (Matzuschita) "B. tuberigenus 5". Gonnermann, Landw. 
 
 Jahrb. Bd.XXIII. p. 657. 
 
55 
 
 B. Lupini (Matzuschita) "B. tuberigenus 7", Gonnermann, Landw. Jalirb. 
 
 Bd. XXIII. p. 657. 
 B. pneumonicus agilis (Schou). Fortschr. d. Med. Bd. III. p. 483. 1885 
 
 See Neumann, Zeitschr. f. klin. Med. Bd. XIII. p. 73. 1888 
 
 B. viguali (Matzuschita) = Bac. [i Vigual, Fliigge. Bd. II. p. 283. 
 B. liquefaciens communis (Sternberg). Fliigge. Bd. II. p. 315. 
 B. rosaceus margarinicus (Jolles and Winkler). Zschr. f. Hyg. Bd. XX. p. 105. 1895 
 B. nitrogenes (Matz.) B. denitrificans II. Burri und Stutzer, Centralbl. f. 
 
 Bakt. Abt. II. Bd. I. p. 362. 1895 
 
 B. erubescens (Matzuschita) = B. oogenes hydrosulfureus Zorkendorfer, Arch. 
 
 f. Hvg. Bd. XVI. p. 391. 1893 
 
 B. subruoiginosus Maschek. 
 
 B. rubefaciens pyogenes (Matzuschita). Centralbl. f. Bakt. Bd. XXIX. p. 378. 1901 
 B. subrubeus (Bact. subrubeum Kern). [Arb. aus d. Hochsch. zu Karlsruhe. Bd. I. 
 
 p. 450.1 
 
 B. thermophilus liquef. aerobius (Oprescu). Arch. f. Hyg. Bd. XXXIII. p. 166. 
 B. tyrogenus Ebenda, p. 171. 1898 
 
 B. subthermophilus (Matzuschita) = B. thermophilus IV Rabinowitsch. Zeitschr. 
 
 f. Hyg. Bd. XX. p. 161. 1895 
 
 B. sacchanphilus (Laxa). Centrabl. f. Bakt. Abt. II Bd. IV. p. 362. 1898 
 
 B. mycoides ruber (B. mycoides roseus?) Matzuschita. Archiv f. Hyg. Bd. XLI. 
 
 p. 251. 1901 
 
 B. Danteci (Le Dan tec). Ann. Past. Bd. V. 1891. p. 656. Named by K ruse, 
 
 Fliigge. Bd. II. p. 270. 
 
 B. apicum (Canestrini) Fliigge, Bd. II. p. 233. 
 B. mesentericus rubiginosus (Senger). Centralbl. f. Bakt. Bd. III. p. 603. 
 
Printed by Hermann Pohle, Jena. 
 

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 131000 
 
 rOLOGY 
 
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 THE UNIVERSITY OF CALIFORNIA LIBRARY 
 

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