270 



These differences hold good in other countries, 

 e.g., in Italy. Here the mortality from malaria 

 in the north is comparatively trifling, while in 

 the south and the islands it is severe. 



Here the difference may be due to differences 

 in climate, but this explanation does not suffice 

 in the examples in India we have mentioned. 



Again, we have great irregularities in the 

 distribution of the species of parasite. The quar- 

 tan, for instance, in the Duars (Bengal) is 

 exceedingly common amongst the native children, 

 but in Lahore it is rare. 



Similar differences have been noted in Algeria, 

 where over large areas the quartan parasite is 

 extremely rare, yet in a few localities it occurs in 

 seventy per cent, of cases (Billet). 



So in India, as a whole, we have certain 

 .small areas where malaria is intense, e.g., the 

 Duars, Jeypore (Madras), and Kanara (Bombay) 

 (Christy), where we also find blackwater fever; yet 

 in others, as in the Central Provinces, where 

 apparently all the conditions are favourable, we 

 have only a moderate intensity. 



We require, then, to examine carefully the 

 endemic indices over large areas in order to get 

 an accurate idea of the variations in endemic 

 malaria. The instances we have given will shew 

 how erroneous it is to say broadly, ' such and 

 such a country is highly malarial,' for while this 

 may be true of one district it might be quite untrue 

 of another. 



Further, after having established these broad 

 data, it will be necessary to make a close survey 

 of each individual district in order to endeavour 

 to explain the factors at work. 



