RES Barber et al.: Malaria in the Philippines 231 
at from 1 to 1.5 kilometers from the town. At the time of our 
survey the larve of A. febrifer were more numerous in this river 
than in any other stream, except one, surveyed in the Philippines. 
Doctor Daywalt informs us that in the wet season there is a 
spring in the town itself at the margin of which larve of A. 
febrifer were found. He sent us some specimens of mature ano- 
pheles caught in houses in the town during the rainy season and 
among these was one A. febrifer. So it is evident that this 
species either breeds in or near the town or is able to reach it 
by flight from a distance. Mangarin is situated in a highly 
malarious region, and there is more or less intercommunication 
with the inhabitants of the San Jose Estate and other places 
where malaria is, or has been, very prevalent. 
Limay, Bataan Province, shows a parasite index of only 6.8. 
It is situated on the coast near the foot of the mountains, and 
a lumber mill is situated in it and connected by a railway with — 
the mountains at the foot of which the town lies. Shortly be- 
fore this region was surveyed for mosquitoes, there had been a 
freshet, so that few larve of any kind were found, but a few 
larve, apparently A. febrifer, were found in a brook at the 
edge of the town. 
Of the coast towns situated well above high tide, Puerto Prin- 
cesa, Palawan Island, shows a parasite rate of 28.6. Numerous 
larvee of A. febrifer and A. rossi were found in a small stream 
at the edge of this town. Like Mangarin, Puerto Princesa is 
in more or less communication with a highly malarious region. 
The results of this work tend to confirm the preliminary 
conclusion of Walker and Barber that the chief carrier of the 
Philippine Islands is Anopheles febrifer. The mosquito survey 
has shown the wide distribution of this species, the abundance 
of its breeding places, and the large numbers of larve often 
found in them. Further it has been shown that this species is 
house-seeking and readily bites human beings. Its distance of 
flight is at least 170 paces, and the number found in houses 
in some localities was large in comparison with the number of 
larvee found in the neighboring breeding places. — 
The distribution of malaria agrees, in general, with the dis- 
tribution of A. febrifer. In every malarious town in which 
it was possible to make an adequate anopheles survey, either 
larve of A. febrifer were found in or near the locality or adults 
were caught in the houses. The high rate of malaria occurring 
in “ditch” towns where A. febrifer breeds in close proximity to 
houses tends to strengthen the evidence against this species. 
