544 APPLICATION OF METHODS OF BACTERIOLOGY 



from this form of dysentery a positive agglutination reaction 

 is often obtained. 



It is pathogenic by both subcutaneous and intraperitoneal 

 inoculation for the ordinary laboratory test-animals i. e. t 

 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 edema, hemor- 

 rhagic exudation, and in delayed cases, more or less of pus 

 formation. The subcutaneous lymph-glands are often en- 

 larged 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 subcu- 

 taneous 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 leukocytes; the pleural and peri- 

 cardial cavities may contain clear fluid; the spleen is swollen; 

 the adrenals and kidneys are congested; 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 matter; there may be ecchymosis 

 in the intestinal mucosa, and Peyer's patches may be 

 enlarged and reddened. 



The distribution of the bacilli varies : sometimes there 

 is a general invasion of the body by the bacilli; at others 

 they are only to be found at the local site of inoculation. 



