I.] THE HISTORY OF THE COMMA-BACILLUS. 7 



as not altogether unimportant for the cholera-process, whilst 

 everything else gave the impression that it was something 

 secondary ; for the bacteria first described always advanced 

 beyond the others, they forced their way farther in, and gave 

 one the impression that they had smoothed the way for the 

 other bacilli. 



" With regard to the contents of the intestine, at first no 

 clear idea could be formed, as the only cases which came 

 before us for examination were not suitable ; in these, also, 

 the contents of the intestine were already putrid and bloody. 

 There were an enormous quantity of various bacteria in 

 these contents, so that there was no possibility of attending 

 to the real cholera-bacilli. Not till I had dissected a couple 

 of acute and uncomplicated cases, in which no haemorrhage 

 had as yet set in, and in which the contents of the intestines 

 had not yet turned to putrid decomposition, did I recognise 

 that the purer and fresher the cases the more did a special 

 kind of bacteria prevail in the contents of the intestines also, 

 and it was soon clear that these were the same bacteria 

 which I had seen in the mucous membrane. This discovery 

 naturally turned my attention more and more to this kind 

 of bacteria. I investigated them in all kinds of ways in order 

 to establish their special peculiarities ; and am able to give 

 the following information regarding them. 



" These bacteria, which I have called comma-bacilli on 

 account of their peculiar shape, are smaller than the tubercle- 

 bacilli. One scarcely forms a correct idea of the thickness, 

 length, and breadth of bacteria by giving their dimensions in 

 numbers ; I therefore prefer to compare the dimensions of 

 bacteria with other objects, so that one can immediately form 

 a tolerably good idea. As the tubercle-bacilli are known to 

 everybody, I will compare the cholera-bacteria with them. 

 The cholera-bacilli are about half, or at most two-thirds, as 



