426 



SPIRILLUM CHOLEIUE ASIATICS. 



Movement of 

 the comma 

 bacilli. 



Involution 

 forms. 



By the employment of this method we also see that 

 the comma bacilli are motile. The movement is as a 

 rule very active, either turning round their axis or shoot- 

 ing forwards; in the case of the longer spirilla it is 

 slower, and more of an oscillating character. The 

 movement is, as a rule, most active at the margin of the 

 drop, in the neighbourhood of the air. 



The comma bacilli multiply very rapidly. When the 

 maximum of development has occurred in a drop culti- 





'G- 



Fig. 119. (After Koch.) Section of the intestinal 

 mucous membrane from a case of cholera. 



A Brunner's gland (a) cut transversely. 



In the interior (b) and between the epithelium and the 



basal membrane (c) are numerous comma bacilli X 



600. 



vation involution appearances generally commence, at 

 first in a few, and later in numerous individuals. The 

 dying bacilli lose their characteristic form, shrivel up or 

 swell out, and in such a state take up the colouring 

 matter only slightly or not at all. In the swollen 

 plumper rod there is often such a subdivision of that 

 portion of the plasma which takes on the stain that, on 

 treatment with aniline colours, an unstained spot remains 

 in the middle of the rod which recalls the appearance 

 of the spores of other bacteria, and has in fact been 

 erroneously looked on as spores. Further, according to 



