256 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XVI. 



"which "wakes" were held over the bodies of individuals who had died of 

 plague in the houses. At the time of this epidemic no rats were found 

 affected with plague. There is good reason to believe, however, that al- 

 though not found, yet the epizotic actually existed ; for, after an interval 

 of a year, a second outbreak occurred, this time among individuals 

 associated with a rag store. Rats affected with plague were found here, 

 and continued to be found affected with the disease in various parts 

 of the city at irregular intervals, for a period of two years. The only 

 epidemic plague associated with this epizotic plague was that which 

 occurred in some five individuals who worked in the rag store, and in 

 other five individuals who worked or lived in the cellars of the Central 

 Hotel. Plague-infected rats were found in the basement of certain tea 

 rooms in Gordon Street. A rat warren was discovered, which, when 

 the burrows were broken up, gave a bag of 67 rats which had either 

 been killed or found dead. Of these 67 rats no less than 40 had plague. 

 Rats affected with the disease were found in other places, and con- 

 tinued to be found, as I have remarked, for nearly two years ; but 

 no plague occurred in men. It is evident we were here dealing with 

 epizotic plague among rats of the species Mus decumanus. You note 

 the diseased animals were found in cellars and burrows — places 

 where rats of the species Mus decumanus are generally found — places 

 where they were more or less isolated from man. Had the epizotic 

 occurred among rats of the species Mus rattus, which inhabit houses, 

 a very different tale would have been told. It is interesting to note 

 the oradual disappearance of plague from Europe about the end of the 

 17th century — a time which was coincident with the invasion of the 

 brown rat and the displacement of the black rat by that species. The 

 species of rat affected by the disease has an important bearing on the 

 spread of plague in man, not from any inherent difference in suscepti- 

 bility to the disease in the particular species of rat, but because of 

 the habits of the species. Another important difference will be noticed 

 when I come to describe the fleas infesting these species of rats. 



Now while there is the striking difference in the habits of the 

 two species of rats, we have equally striking differences in the habits 

 of the people inhabiting Europe and the East. I have referred to the 

 fact, that, perhaps, the invasion of Europe by the brown rat may have 

 been aided by the change in the habits of the people. As pucca 

 buildings began to be erected, as drainage system developed, ^as stables 



