84 THE BACTERIA IN ASIATIC CHOLERA. [CH. 



morphological appearances, Koch had found, as he might 

 have done by more careful examination, that in the fluid of 

 the mouth of man, in the intestinal contents of various in- 

 testinal disorders in man and animals, and in the normal con- 

 tents of the intestines of some animals, comma-bacilli iden- 

 tical in morphological respects with the comma-bacilli in 

 Asiatic cholera were constantly present, I am inclined to 

 think that he would have adhered to his opinion formed be- 

 fore he went out to Egypt, viz., that the distribution of the 

 comma-bacilli in the intestine in cases of cholera (sent him to 

 Berlin from India some time previously), proves them to be 

 septic organisms. 



It is, I think, necessary to go back to this history of the 

 discovery 'of the choleraic comma-bacilli, in order to show 

 that the importance ascribed to them by Koch in relation to 

 cholera may have had a good deal to do with his inability to 

 find comma-bacilli anywhere else except in cholera cases. 

 Koch says that since comma-bacilli occur only in cholera, 

 and since he has failed to find them in the normal intestine, 

 he concludes that the organisms and the disease stand in a 

 direct relation. Now from his having failed to find comma- 

 bacilli in a variety of localities where we now know that they 

 constantly occur, his positive statement that they do not 

 occur in the normal intestine loses a good deal of its value ; 

 for, as will be pointed out below, even if they did occur in 

 very small numbers amongst the myriads and myriads of 

 bacteria normally inhabiting the alimentary canal, it would 

 be well-nigh impossible to demonstrate them ; it would at 

 any rate require long and exhaustive examination by many 

 workers to establish their presence or absence on a reliable 

 basis. If any one who has failed to find comma-bacilli in a 

 variety of localities in which he has searched for them, but in 

 which they have been shown by others to exist, tells us that 



