CHOLERA. 167 



magnifying power ( x 800) beneath the loosened epithelium 

 of the villi, in the follicles, and in the surrounding connec- 

 tive tissue. They are especially numerous near the ileo- 

 caecal valve, and are distributed, not in masses, but usually 

 in ones, twos, and threes, scattered thickly through these 

 tissues. 1 



On post-mortem examination of the guinea pigs, in which cholera had 

 been experimentally produced, "the blood was fluid, thicker and darker 

 than natural, the tissues of the thoracic and abdominal walls were re- 

 markably dry, the small intestine was throughout distended, congested, and 

 paralyzed-looking, and occupied a much larger proportion of the abdominal 

 cavity than usual. The caecum was distended with fluid or semi-fluid con- 

 tents. If the animal died early the fluid was not quite clear in the small 

 gut, there being present traces of food ; still the watery character was very 

 manifest, and mucous flakes were abundant. If the animal died on the 

 second or third day no food remains were to be seen, and the fluid in the 

 small gut was the counterpart of the typical cholera stool of man. In 

 either case the comma bacilli were demonstrated microscopically, and by 

 cultivation as in man." 



While the organisms in the broth injected could be frequently counted in 

 a microscope field, in a drop of the small bowel contents from an animal 

 having received such broth, the bacilli might be so numerous that counting 

 them, without dilution of the fluid examined, was an impossibility. On 

 floating the bowel in water, the stripping of the epithelium could be well 

 demonstrated "immediately after death," a fact which appears to dispose of 

 Macnamara's assertion that this separation of the membrane is always a 

 post-mortem appearance. In animals which died about the eighth day 

 the appearances were very similar to those met with in cases of Asiatic 

 cholera, when the patients have succumbed during the stage of reaction, 

 and no bacilli can be found in the intestinal canal or in the surrounding 

 tissues. In the earlier stages the bacilli can be demonstrated in sections 

 lying under the partially-detached epithelium, or in the lumina of Lieber- 

 kuhn's follicles. 



In fluid cultivations, as has already been mentioned, the 

 comma bacilli, or little groups of them, assume various forms, 

 all of which, however, may be looked upon as made up of 

 more or less perfect spirals. At the point of division, just 

 before division take places, there is a small clear space which, 

 by some authorities, has been looked upon as a spore. In some 

 of Macleod's preparations this appearance was so marked that 

 it was difficult to convince oneself that it was not due to 

 actual spore formation, but as drying for twenty-four hours 

 completely destroyed the activity of the bacillus in which 

 these clear spaces were most marked, and as they could not 



1 It is not my intention to give the complete pathological anatomy of cholera, 

 except so far as it is associated with the presence of the cholera bacilli. 



