MOSQUITO BREEDING IN SALT AND FRESH WATER. 339 



If this was the case with M. ludlowii Theob., then the ease with which 

 the larva? might be carried by the river currents toward to sea would 

 explain their present marine or littoral habitat. 



HYGIENIC FEATURES. 



The most important feature of this discovery from an economic stand- 

 point appears to be its bearing upon the general dispersal of pernicious 

 malaria in the Philippines. There would appear to be no barrier against 

 it from the standpoint of geographical position, either in altitude or in 

 remoteness from the sea. In fact, the demonstration of the parasites 

 of aastivo-autumnal malaria in individuals who have never been out of 

 the highland region, would be an accusation of overwhelming force against 

 M. ludlowii Theob., which has already been shown to carry the same 

 parasite at sea level. 4 



In Cervantes the crescent form of the jDarasite was found in the blood 

 of a little girl, P. C, aged 6 years and 5 months who had been suffering 

 from chills and fever for about two months previous to the time when 

 I saw her. She had always lived in the town of Cervantes and therefore 

 certainly contracted the disease locally and with M. ludlowii Theob. as 

 the transmitting agent. 



CONCLUSIONS. 



The most obvious conclusions are: 



That Myzomyia ludlowii Theob. is a species which, in the Philippines, 

 breeds in both salt and fresh water. 



That altitude has (up to 1,500 meters) no appreciable influence upon 

 its development. 



That there is little hope of ridding a community, like Cervantes, of 

 this insect, owing to the peculiar topographical features which are 

 practically irremediable because of their extent. 



That the present investigation made in a region where M. ludloivii 

 Theob. is found in great abundance and where no other anopheline was 

 encountered, gives a strong additional proof of its role as a transmitter 

 of wstivo-autumnal malaria. 



*This Journal, Sec. B. (1907), 2, 531 et seq. 



