314 BACTERIOLOGY. 



hogs, horses, monkeys, cats, chickens, and sparrows. 

 Pigeons, hedgehogs, and frogs are immune, and dogs 

 and bo vines are apparently so. 1 Animals succumb to 

 subcutaneous inoculation in from two to three days. 

 According to Yersin, the site of subcutaneous inocu- 

 lation becomes cedematous and the neighboring lym- 

 phatics are enlarged in a few hours. After twenty-four 

 hours the animal is quiet, the hair is rumpled, tears 

 stream from the eyes, and later convulsions set in, which 

 last till death. The results found at autopsy are : blood- 

 stained oedema at the site of inoculation, reddening and 

 swelling of the lymphatic glands, bloody extravasation 

 into the abdominal walls, serous effusion into the pleu- 

 ral and peritoneal cavities ; the intestine is occasionally 

 hypersemic, the adrenal bodies congested, and the spleen 

 enlarged, often being studded with grayish points, sug- 

 gestive of miliary tubercles. The plague, or pest, ba- 

 cillus is detected in large numbers in the local oadema, 

 the lymph-glands, the blood, and the internal organs. 



As is the case in general with the group of hemor- 

 rhagic septicaemia bacteria, the members of which it 

 resembles in certain other respects, when death does not 

 result promptly after infection there is usually only 

 local evidence of the inoculation, the distribution of the 

 micro-organisms throughout the body being considera- 

 bly diminished. 



Animals that survive inoculation with this organism 

 usually exhibit a certain degree of immunity from sub- 

 sequent infection. 



Nuttall 2 notes that feeding-experiments have resulted 



iNuttall: Centralblat fur Bakteriologie uud Parasitenkunde, 1897, 

 Abt. i. Bd. xxii. S. 97. 

 2 Nuttall: loc. cit. 



