v PLAGUE IN THE EAT 119 



the j invariably, and without difficulty, picked out and 

 grouped quite correctly the cultures of the two strains. 



The parallel experiments made with the strain from 

 the protected rat (type No. 2) are these : — 



Experiment 7. — A rat (rat Ik) was inoculated 

 cutaneously with a trace of the growth of a two days 

 old agar subculture of the bubo of the rat 1b mentioned 

 in Series A. (experiments with strain of B. pestis derived 

 from protected rat). This rat was found dead on the 

 seventh day. Post mortem : — The inguinal glands were 

 found swollen and hemorrhagic ; small intestine and 

 lungs congested ; spleen not enlarged. The inguinal 

 glands were crowded with B. pestis, which by culture 

 was proved to be of the type No. 2. The heart's blood 

 did not yield colonies of B. pestis. The culture was 

 quite liquefied in forty-eight hours, owing to con- 

 tamination. 



The result of this experiment is, then, quite con- 

 firmatory of experiments mentioned in Series A., viz. 

 that B. pestis of type No. 2 does not cause the patho- 

 logical changes typical of B. pestis type No. 1, its effects 

 being chiefly bubo with crowds of B. pestis (type 2) 

 in it. 



Experiment 8. — A rat, 1l, was inoculated cutaneously 

 with a two days old agar subculture of material from the 

 bubo of rat lc of Series A., which had itself been inoculated 

 with a subculture of the bubo of rat 1b. 



Eat 1l was found dead on the fifth day — it died in 

 the night between the fourth and fifth days. The post- 

 mortem examination showed the inguinal glands corre- 

 sponding . to the inoculated side swollen and hemorrhagic ; 

 small intestine relaxed, containing sanguineous mucus ; 



