i8o 



MICRO-ORGANISMS AND DISEASE. [CHAP. 



Rietsch, by Koch and others, viz., death following in some 

 of the animals after injection of choleraic mucus-flakes or of 

 cultivations of comma-bacilli into the cavity of the small 

 intestine, were not due to cholera, but were probably due 

 either to the operation or to septic poisoning. Rodents, 

 carnivorous animals, and monkeys must be considered 

 insusceptible to cholera. 1 There is direct evidence that the 

 water contaminated with choleraic evacuations only, and of 

 course with comma-bacilli, when drunk by a large number 

 of persons did not produce cholera ; there is no definite 



FIG. 103. 



From a preparation of mucus flakes of the ileum of a case of typical cholera. 

 Comma-bacilli and minute straight bacilli, singly and in masses . Three lymph- 

 corpuscles containing in their interior numerous small straight bacilli. 



evidence that a cholera patient elaborates ready virus and 

 passes it out with the evacuations. 



Comma-bacilli of various species have been discovered in 

 other diseases of the alimentary canal ; in the fluid of the 



1 In connection with all the experiments said to have yielded positive 

 results on guinea-pigs, it must be mentioned that a variety of bacteria 

 are known, which although derived from normal but putrid secretions, 

 act very poisonously on rodents, e.g. the bacillus isolated by Bienstock 

 from normal human faecal matter ; the dumb-bell micrococcus isolated 

 by Pasteur and Sternberg from normal saliva, by Escherich from the 

 stool of milk-fed infants, by myself from sputum of pneumonia. 



