208 INFECTIONS OF THE DIGESTIVE TRACT 



In this connection it should not be forgotten that Klein 

 isolated from the fseces in an outbreak of diarrhoea an 

 organism which very probably is identical with B. 

 aerogenes capsulatus. This organism was given the name 

 B. enteritidis sporogenes. The position of the organism 

 described by Klein is open to some suspicion because 

 while it is stated by him to produce gas and butyric acid 

 in the very characteristic manner observed by Welch 

 and Nuttall for B. aerogenes capsulatus, it differs from 

 the latter in having motility and apparently in sporulat- 

 ing much more readily. Cultures sent by Dr. Klein to 

 Professor Welch contained bacilli which agreed in every 

 detail with pure cultures of B. aerogenes capsulatus. 1 

 As, however, the faeces sometimes contain bacteria 

 having the morphology of B. aerogenes capsulatus but 

 differing from this organism in forming spores much 

 more readily, it is possible that Klein was in reality 

 dealing with impure cultures of B. aerogenes capsulatus. 

 I am disposed to believe, after a careful review of the 

 available evidence on the subject, that Klein had an 

 organism distinct from B. aerogenes capsulatus, though 

 he may have had this also. 



B. aerogenes capsulatus belongs in the group of anaerobic 

 putrefactive microorganisms capable of making butyric 

 acid and hydrogen. If careful biochemical tests be made, 

 there is no difficulty about distinguishing the gas-bacillus 

 from other anaerobes that occur in the human diges- 

 tive tract. The bacillus of malignant oedema is some- 



1 See "Manual of Bacteriology by Muir and Ritchie," American 

 Edition, p. 354, 1904. 



