442 BACTERIOLOGY. 



faculty to so limited a degree as to make the matter 

 doubtful. 



When mixed with blood-serum of individuals suffer- 

 ing from this form of dysentery a positive agglutination 

 reaction is often obtained. 



It is pathogenic by both subcutaneous and intraperi- 

 toneal inoculation for the ordinary laboratory test-ani- 

 mals — i. e., mice, guinea-pigs, and rabbits. 



When injection is made beneath the skin, death results 

 in from two to four days, according to the dose and viru- 

 lence of the culture used. 



The most striking lesion is that observed at and about 

 the site of inoculation. This consists of cedema, hem- 

 orrhagic exudation, and, in delayed cases, more or less 

 of pus formation. The subcutaneous lymph-glands are 

 often enlarged and reddened, and a serous exudation is 

 frequently encountered in the great serous cavities. Of 

 the animals mentioned, the rabbit is most apt to survive 

 the subcutaneous inoculation. 



When injected into the peritoneal cavity, death takes 

 place in from a few hours to five or six days, according 

 to dose and virulence of the culture used. 



At autopsy the superficial lymph-glands are enlarged 

 and reddened ; the peritoneum contains more or less of 

 turbid fluid and small masses of leucocytes ; the pleural 

 and pericardial cavities may contain clear fluid ; the 

 spleen is swollen ; the adrenals and kidneys are con- 

 gested ; there may be a grayish exudate over the liver, 

 spleen, and intestines, the bloodvessels are injected ; the 

 small intestine may be filled with semifluid or fluid mat- 

 ter ; there may be ecchymosis of the intestinal mucosa, 

 and Peyer's patches may be enlarged and reddened. 



The distribution of the bacilli varies : sometimes 



