860 



SCIENCE. 



[N. S. Vol. XXIV. No. 626. 



were hemorrhagic, (Edematous and showed 

 necrotic changes which extended in some in- 

 stances to the muscles. Gas-formation was 

 not usually noted as a prominent feature. 

 These pathological alterations were not con- 

 fined to the site of inoculation but had ex- 

 tended to the subcutaneous connective tissues 

 throughout the body and were especially pro- 

 nounced in the axillae and in the groin. It is 

 unnecessary to enter here into the details as 

 to the character of the organisms recovered 

 from these lesions. 



We may contrast with these findings the 

 observations made upon herbivorous animals, 

 including the buffalo, goat, horse, elephant 

 and camel. In the case of the camel, elephant 

 and horse the preponderant bacteria in the 

 Gram-stained fields were small Gram-negative 

 organisms which were regarded as special 

 forms of B. coli. In the case of the goat the 

 fields contained some Gram-positive bacteria 

 and of the Gram-negative ones a considerable 

 number were of considerably greater length 

 than the dominant small forms which were 

 regarded as belonging in the class of colon 

 bacilli. In the case of the buffalo, mixed 

 fields were found as regards the Gram-staining 

 and many of the positive organisms were 

 found to be small diplococci and small bacilli. 

 In none of these animals were seen any organ- 

 isms suggesting B. aerogenes capsulatus ex- 

 cepting in the case of the buffalo where the 

 number of bacilli of this type was very small. 

 Spore-holding organisms were not observed, 

 but moderate numbers of free spores were 

 noticed in all the fields except those from the 

 elephant. In the fields showing the largest 

 number of spores their occurrence was far less 

 frequent than in the lion, tiger, wolf or cat. 



The mixed flora of these different herbivo- 

 rous animals, grown upon peptone bouillon, 

 failed to show the production of methyl mer- 

 captan excepting in the case of the horse, 

 where a moderate reaction was obtained. 



Observations were also made upon the effect 

 of suspensions of the mixed flora from her- 

 bivorous animals when injected subcutane- 

 ously. The quantities of suspension used 

 were usually about twice as great as in the 

 case of the suspensions from the carnivorous 



animals. With the exception of the suspen- 

 sions obtained from the horse, the pathogen- 

 icity of these suspensions was found to be 

 slight, the guinea-pigs frequently living two 

 or thi'ee days or entirely recovering. In the 

 horse were found hemorrhagic and (Edematous 

 lesions with necrosis, similar to those found 

 in the carnivorous animals. These lesions 

 were, however, less pronounced than in the 

 case of the suspensions from the carnivorous 

 animals. In the case of the elephant a con- 

 siderable quantity of fibrinous exudate was 

 found about the point of inoculation. No 

 oedema or necrotic change was observed in the 

 subcutaneous tissues. 



A further confirmation of the radical differ- 

 ences existing in the intestinal tracts of car- 

 nivora and herbivora is furnished by a series 

 of observations with the Welch-Nuttall incu- 

 bation test. Suspensions were made from the 

 feces of all the types of animals mentioned 

 and equal quantities of these suspensions were 

 infused intravenously into a series of living 

 rabbits. The rabbits were then quickly killed 

 and incubated. On examination after twenty- 

 four hours it was found that all the rabbits 

 infused with suspensions from carnivora 

 showed in an extreme degree the characteristic 

 putrefactive changes in the liver, cellular tis- 

 sues, etc., induced by pure cultures of B. 

 aerogenes capsulatus or of the bacillus of 

 symptomatic anthrax. The rabbits infused 

 with suspensions made from the feces of the 

 herbivora showed similar but very much 

 slighter changes in each case. The results 

 for each group of animals separated the her- 

 bivora sharply from the carnivora. Examina- 

 tion of the livers showed the number of bac- 

 teria in the carnivorous series to be many 

 times greater than in the herbivorous series. 

 The microorganisms were regarded as being 

 almost certainly B. aerogenes capsulatus on 

 account of their morphology and failure to 

 sporulate. The bacilli of symptomatic an- 

 thrax readily sporulate in the incubated rab- 

 bits. The gas-bacillus (B. aerogenes capsu- 

 latus) does not sporulate under these circum- 

 stances. 



These differences in the appearance and be- 

 havior of the bacteria derived from typical 



