62 ORIENTAL PLAGUE chap. 



juices of the bubo, and of the heart-blood, proved conclu- 

 sively that the microbe was not B. pestis. All these 

 cultures were pure growths of one and the same species — 

 which was not B. pestis. Numerous other experiments 

 with the same material gave like positive results. 



To sum up the facts so far with reference to the 

 George Royle rat : there was obtained by experiment on 

 the guinea-pig, as also by culture, with the inflamed lung 

 of the rat in question, a microbe which acted pathogeni- 

 cally in the guinea-pig, both subcutaneously and intraperi- 

 toneal^, and on the rat when injected subcutaneously. 

 The result of the inoculation of these animals was pro- 

 duction in them of a hsemorrhagic septicaemia, with the 

 copious presence, in the exudations of the inflamed parts 

 and tissues, of a single definite species of bacillus. The 

 post-mortem appearances were in their character not un- 

 like those of plague, except that the spleen was not much 

 enlarged, or at least not so distinctly as in plague. The 

 microbe recovered from the tissues of the dead animals 

 showed in its general morphology and staining power a 

 remarkable similarity to B. pestis ; so much so that film 

 specimens, such as are shown, would no doubt justify the 

 provisional diagnosis of B. pestis. I refer here particularly 

 to the stained film specimen of the peritoneal exudation 

 of a guinea-pig dead after intraperitoneal injection, shown, 

 and to the film specimen of the spleen juice of a guinea- 

 pig dead after injection subcutaneously with culture 

 (Figs. 47 and 48). 



Another point which it is necessary to insist on is the 

 important one that neither in the guinea-pig nor in the 

 rat have I been able to produce with this bacillus, whether 

 using the animal tissues or culture, any positive result 



