82 Records of the Indian Museum. [\'ol. Ill, 



it is one for sanitary science to deal with. It was clear, however, 

 that this attempted rat extermination provided an opportunity of 

 gaining information regarding the distribution of the various kinds 

 of rats throughout the country, since large numbers of them could 

 be collected from different localities and compared ; from this 

 comparison information of direct or indirect practical importance 

 might be gained. It has been kept well in view that to 

 obtain such information was the purpose of the present inquir}'. 

 Although the practical value of the information may not seem 

 great , it is hoped that the facts themselves will be of suggestive 

 value to those more acquainted with the aetiology of plague than 

 the writer. 



A Comparison between Rats found in the Ports of Bombay, 

 Calcutta, Madras and Rangoon. 



This question is of importance, for as a rule the sea-ports are 

 the doors by which the infection of plague enters a country. In all 

 probability plague entered the Bombay Presidency and Upper 

 India by the port of Bombay, and it certainly entered Burma 

 through Rangoon. 



In comparing the rodents of the four great ports, one important 

 fact stands out. Mus decumanus is common both in Bomba}* and 

 Calcutta; it is not uncommon in Rangoon, but it is absent from 

 the city of Madras. There must be a definite cause to account for 

 this. There is another peculiarity in the rodents of Madras. The 

 bandicoot is very rarely found in Bombay. It is uncommon in 

 Calcutta, where it is occasionally found burrowing near the numer- 

 ous tanks of that city. It is absent from Rangoon ; a smaller sort of 

 bandicoot is common there. In Madras, however, the large bandi- 

 coot is so common that the populace can kill as mau}^ as one hundred 

 of them daily, although it is too large to enter traps and has to be 

 killed by blows from sticks. The Madras bandicoot is an outdoor 

 rat, a dweller in drains and outhouses, having a total length of 

 about two feet ; it w^ould not be tolerated in the houses, where it 

 could not move without detection. Its mode of life is therefore 

 essentially the same as that of Mus decumanus. The rodent fauna 

 of Madras is therefore peculiar in two ways, in the presence of the 

 bandicoot and in the absence of Mus decumanus. These two pecu- 

 liarities are obviously associated with one another. The bandicoot 

 occupies exactly the same position among the rats of Madras that 

 Mus decumanus occupies among the rats of Bombay and Calcutta, 

 and since the bandicoot is much more powerful even than Mus 

 decumanus, there is no place for this latter rat in Madras unless it 

 can change its habits entirely. A consideration of the rodents of 

 Rangoon lends support to this view. In Rangoon Mus decumanus 

 is to be found, but it is much less common than in Bombay or 

 Calcutta ; this may be due to the presence of the small bandicoot, 

 Gunomys varius, which is, like Mus decumanus, an essentially 

 outdoor rat, and must compete with this latter species. Since the 



