38 THE GROWTH OF GROUPS 



points would have been examined more carefully, if 

 from the first the work had been undertaken in order to 

 throw light on the manner of evolution. 



The destruction of rats was carried out in many of 

 the large towns throughout India and Burmah on a large 

 scale, according as funds and other local conditions 

 allowed. To mention one case ; in Rangoon the muni- 

 cipal authorities paid daily to the townsfolk sums of 

 money varying from 25 to 30, as rewards for the 

 bodies of rats ; indeed the whole system of extermination 

 in that town must have cost the municipality as much 

 as 40 daily, and this rate of expenditure was continued 

 for over a year. 



In July 1907, the Government of India issued a 

 circular to the local sanitary departments in India and 

 Burmah, inviting them to co-operate with the Indian 

 Museum in studying the varieties and habits of the 

 common rats of those countries, with a view to obtaining 

 knowledge that might be useful against plague. This 

 circular met with considerable response, so that within 

 the following year over two thousand rats were received 

 by the Museum from different places. It was my duty 

 to examine these specimens at the Museum, and also 

 to visit the towns of Rangoon, Madras, Bombay, Poona, 

 Belgaum, where it was possible to examine the animals 

 in large numbers and to inquire into their circumstances. 

 It was while visiting these places that the more interesting 

 information was obtained. 



At the commencement of the investigation, when 

 large numbers of specimens were being collected at the 

 Museum from various places, the question arose as to 

 how they should be classified. The great majority of 



