v.j VARIOUS SPECIES OF COMMA-BACILLI. 85 



in the normal human intestine no comma-bacilli occur, I 

 think we shall be justified in showing some hesitation before 

 accepting his dictum. What we do know of the characters, 

 morphological and cultural, of the innumerable species of 

 bacteria occurring in the different parts of the normal human 

 intestine, is utterly insignificant as compared with what we 

 do not know of them, and a great deal of work will have to be 

 done still before any one is justified in saying that such and 

 such a form present in a certain disorder of the intestine is 

 not present in the normal state. Of course, if there are other 

 evidences, such as the direct test of physiological action on 

 the animal body, a conclusion can be drawn with certainty, 

 but in the absence of such a test and as I shall show this 

 test is not forthcoming as regards the cholera-bacilli and 

 cholera it is quite unjustifiable for any one to pronounce so 

 definitely as Koch did. Supposing that a particular patho- 

 logical state of the ileum, particularly the mucus-flakes 

 therein, were to favour the multiplication of the comma-bacilli 

 already present in very small numbers in the normal state, 

 then we should not be surprised to find that in choleracomma- 

 bacilli are abnormally numerous (see v. Emmerich's statements 

 in the Archiv f. Hygiene, Band III.). 



Mr. Watson Cheyne, in the discussion on Asiatic cholera 

 at the Medico-Chirurgical Society (March 1885), was 

 thought by some present to have made a great point when 

 he asked : How is it that if you want to demonstrate Koch's 

 cholera-bacilli you have only to examine the intestinal con- 

 tents of cholera cases, be they in India, in Egypt, France, or 

 anywhere else, while you cannot find them in other cases of 

 disease ? No doubt, cholera being a disease peculiar to the 

 human species only, and assuming that the cholera-intestine 

 favours the multiplication of the comma-bacilli, it would 

 follow that they are easily demonstrable in such cases ; but 



