THE GASTRIC CONTENTS AND VOMIT 163 



The Boas-Opplcr bacillus, or B. geniculatus, is very charac- 

 teristic of carcinoma of the stomach, though it does not occur 

 in every case. It is very rare in other conditions ; I have seen 

 it occasionally in simple chronic gastritis, but here it is present 

 in numbers which are scanty as compared with the profusion 

 in which it occurs in malignant disease. It is a bacillus of 

 larg'e size, and has a, tendency to grow into long threads, 

 which are readily visible under a J-inch lens (Plate IV., Fig. 5). 

 In a wet specimen these threads usually seem continuous, but 

 on examining a dried and stained specimen, they may be seen 

 to be composed of bacillary segments, much like the chains 

 of the anthrax bacillus. In a wet unstained specimen these 

 threads are very easily recog'nized, as they are highly refrac- 

 tile and are non-motile. Another characteristic feature is 

 the presence of an obtuse angle in some portion of the 

 length of many of the threads, whence the name B. geni- 

 culatus is derived. The organism does not form spores. It 

 stains by Gram, and I have noted in several cases the presence 

 of a phenomenon which is very rare amongst bacilli, that of 

 longitudinal fission in a small number of the chains, which 

 thus come to form double rows of bacilli in close lateral ap- 

 proximation. That this is not a mere effect of staining is 

 shown by the fact that occasionally the two bacilli at one end 

 of this double thread will turn away from one another, so that 

 it looks as if there were true branching" at the extremity of the 

 filament. 



Cultures may readily be obtained on media rather highly 

 acidified with lactic acid, but are not requisite for the identifi- 

 cation of the bacillus. 



In addition to the Boas-Oppler bacillus, the vomit may con- 

 tain a few yeasts, distinguished by their large size, oval or 

 spherical shape, and by the way in which they reproduce them- 

 selves by budding; there may also be a few bacteria of other 

 sorts. But in many cases the bacilli are present in a state of 

 almost absolute purity, and in large numbers, so that they 

 form tangled masses. 



In nearly all cases in which the bacillus is found the vomit 

 contains no hydrochloric acid, or only a trace. To test for it 

 filter some of the vomit and place a drop or two of the filtrate 

 on a white porcelain tile; place a drop of a 0'5 per cent, alco- 

 holic solution of dimethyl-amido-azo-benzol close to it and 



