﻿IX, B, 5 Walker and Barber: Malaria in the Philippines 391 



The larvse were found always along the banks of densely shaded 

 brooks, limited in distribution, and more plentiful during the 

 cool season. 



Schiiffner (1902) attempted experimental infections at Deli, 

 Sumatra, with an anopheline described by him as "Anopheles la," 

 which he considered a variety of his "Anopheles I" (Anopheles 

 rossii). From his description and figure this species appears 

 to be Anopheles maculatus. He was unable to get this species 

 to bite or to suck human blood. 



Stephens and Christophers (1906) list Anopheles maculatus 

 among the species that have been proved to be capable of trans- 

 mitting malaria, but in view of the confusion existing at the time 

 they write as to the identity of this species their statement is not 

 conclusive. In their diagnosis of this species they state that 

 the female of Anopheles maculatus has four white bands on the 

 palpi, which does not correspond to the revised species of Stanton, 

 but rather to Anopheles karwari. 



Stanton (1912) states that both he and Doctor Watson have 

 found this species infected in nature, in the Federated Malay 

 States, and that he has been able to infect it under experimental 

 conditions with the parasites of subtertian malaria. 



One other species, Anopheles {Nyssorhynchus) fuliginosus 

 Giles, has been bred from our collection of larvse, but not in suf- 

 ficient numbers to determine its ability to transmit malaria. 

 This species, however, is included by Stephens and Christophers 

 (1906) among those capable of transmitting malaria; and Stan- 

 ton (1912) states that he has infected Anopheles fuliginosus 

 experimentally. 



II. METHODS 



This investigation was conducted at the Calamba Sugar Estate, 

 Canlubang, Laguna Province, Luzon, about 60 kilometers from 

 Manila. A moderate amount of malaria existed there among the 

 Japanese and Filipino laborers. As malaria was not prevalent 

 in Manila, Canlubang offered a satisfactory place for carrying 

 on our experiments within a reasonable distance from the Bureau 

 of Science. The officials of the Calamba Sugar Estate cooperated 

 freely in the investigation. We are especially indebted to the 

 resident physician of the company. Dr. Isaac S. Diller, who not 

 only made available to us the hospital and patients for infection 

 experiments, but took us into his home and permitted us to use 

 one of his rooms in which to set up our temporary laboratory. 



The Calamba Sugar Estate is situated in Laguna Province, 

 Luzon, near the borders of a large lake, Laguna de Bay. Along 



