vii INFECTION OF ANIMALS WITH PLAGUE 187 



groin. Guinea-pig No. 10, which appeared otherwise 

 lively on July 5, was killed on that date, and on post- 

 mortem examination showed the following conditions : — 



Extensive oedema over abdomen and chest ; about the 

 place of inoculation a big cavity filled with grumous fluid. 

 Spleen not enlarged, no bacilli in it. In the inguinal 

 fluid were crowds of diplococci and streptococci ; as also 

 numerous bipolar bacilli like B. pestis. With a dilution 

 of the inguinal fluid an agar plate was made, and this 

 brought forth crowds of colonies just like those of 

 B. pestis. A guinea-pig, No. 11, was injected with one 

 of these plague-like colonies. This animal was found dead 

 on the fifth day, and gave evidence of typical plague with 

 the typical distribution of B. pestis in the bubo and 

 spleen. 



Guinea-pig No. 9, which had been injected with the 

 "rice-gelatine," developed a big abscess in the groin and 

 thigh ; on the eighth day it was quiet and off its feed, 

 and the bubo having opened spontaneously was discharg- 

 ing pus. This animal, which was better and fairly lively 

 again on the thirteenth day, was now killed, and showed 

 the following post-mortem appearances : — In the inguinal 

 region and about the thigh was a big cavity containing 

 grumous creamy pus ; spleen and liver and also lungs 

 showed numerous minute white nodules. In the pus of 

 the inguinal abscess were numerous clumps of B. pestis. 



In the next series a number of animals were inoculated 

 with earth and with sand which, after addition of small 

 particles of plague organs, had been dried for various 

 periods at the ordinary temperature of the laboratory. 



Experiment 6. — Of a guinea - pig dead on July 7 



