258 



Those in which zygote formation seemed 

 less abundant were : — 



M. rossii 

 M. turkhudi 

 M. barbirostris 



It should be noted, however, that in these 

 experiments M. rossii became infected, while in 

 nature it has never been found infected by us. 



There are, moreover, many considerations 

 which lead to the conclusion that in nature all 

 species of Anopheline are not equally concerned in 

 the transmission of malaria. 



We may have countless numbers of M. rossii, 

 as in Calcutta (environs), and get a malarial index 

 of o, and this appears to hold good in Madras, 

 Bombay, and, as far as our observations go, 

 universally. On the other hand, where we find 

 M. listoni, M. culici fades, P. jeyporensis, in India, 

 we have a high endemic index. 



The group of mosquitoes, those associated 

 with intense malaria, are small dark mosquitoes 

 with unhanded legs [Myzomyia, group i). 



M. FUNESTA AND P. COSTALIS IN AfRICA 



The former mosquito is, like M. listoni, 

 which it closely resembles, a breeder in clean 

 waters, streams, springs, etc., while P. costalis is 

 found breeding in shallow pools about houses and 

 frequents towns (in Africa), which M. funesta 

 does not. 



M. funesta was found by us to be infected 

 in the Lagos hinterland to the extent of twenty- 

 five to fifty per cent. 



