CULTIVATION 463 



biliary passages. Greig found, in a large series of post-mortem 

 examinations, that the cholera organism was present in the 

 gall-bladder in more than a quarter of the cases, and that, in a 

 considerable number of these, distinct pathological changes were 

 present. He has found it also in the urine, lungs, and spleen. 

 Another interesting fact observed by him was that in rabbits 

 inoculated intravenously with the living organism for the 

 purpose of obtaining agglutinating sera, infection of the gall- 

 bladder and the formation of gall-stones not infrequently 

 occurred. The all-important factor in the" pathology of the 

 disease, however, is the absorption of toxins from the bowel. 

 In cases in which there is the characteristic "rice-water" fluid 

 in the intestines, they occur in enormous numbers — almost in 

 pure culture. The lower half of the small intestine is the part 

 most affected. Its surface epithelium becomes shed in great 

 part, and the flakes floating in the fluid ^onsist chiefly of masses 

 •of epithelial cells and mucus, amongst which are numerous 

 spirilla. The spirilla also penetrate the follicles of Lieberkiihn, 

 and may be seen lying between the basement membrane and the 

 epithelial lining, which becomes loosened by their action. In 

 some very acute cases there may be relatively little desquamation 

 of epithelium, the intestinal contents being a comparatively clear 

 fluid containing the spirilla in large numbers. In other cases 

 of a more chronic type, the intestine may show more extensive 

 necrosis of the mucosa and a considerable amount of haemorrhage 

 into its substance, along with formation of false membrane at 

 places. The intestinal contents in such cases are blood-stained 

 and foul-smelling, there being a great proportion of other 

 organisms present besides the cholera spirilla (Koch). 



Cultivation. — (For methods, see p. 474.) 



The cholera spirillum grows readily on all the ordinary media, 

 and, with the exception of that on potato, growth takes place at 

 the ordinary room temperature. The most suitable temperature, 

 however, is that of the body, and growth usually stops about 

 16° C, though in some cases it has been obtained at a lower 

 temperature. Abundant growth occurs on media with suffici- 

 ently alkaline reaction to inhibit the growth of many intestinal 

 bacteria, e.g., Dieudonne's medium, p. 46. 



Peptone Gelatin. — On this medium the organism grows well 

 and produces liquefaction. In puncture cultivations at 22° C. 

 a whitish line appears along the needle track, at the upper part 

 of which liquefaction commences, and as evaporation quickly 

 occurs, a small bell-shaped depression forms, which gives the 

 appearance of an air-bubble. On the fourth or fifth day we get 



