DAA The Philippine Journal of Science 1915 
are averse to the use of bed nets. In a temporary hospital in 
a very malarious region in Luzon, which we visited before day- 
light in order to observe the behavior of mosquitoes, we found 
but few of the nets in use, although nearly all beds were provided 
with them. 
In summary, we believe that the destruction of larve by larvi- 
cides and where practicable by the abolition of breeding and 
lurking places offers more encouragement than any other anti- 
malarial measures in the Philippines. These measures should 
be supplemented by others as conditions advise. Where re- 
sources are adequate, all breeding places of all mosquitoes should 
receive attention, but in case means are limited, the stream 
breeders, Anopheles febrifer and A. maculatus, should be erad- 
icated or much reduced, and the streams should be freed from 
them for as great a distance as possible from towns or camps. 
The destruction of these species is made easier by the restricted 
nature of their breeding places, and the cleaning of a very 
jungly stream has been shown to be a practical possibility. 
Filarize were found only once during this work. No special 
search was made for them, but species occurring in the blood 
during the day must be very uncommon among Filipino children, 
else they would have been oftener observed in the course of 
examination of thousands of thick smears. In the one positive 
case, an adult Japanese at Canlubang, filariz were found in blood 
specimens taken at midday on several successive days, but were 
fewer than in specimens taken early in the morning. 
GENERAL SUMMARY 
1. The commonest species of Anopheles in the portion of the 
Philippines covered by our survey are A. rossii, A. febrifer, A. 
barbirostris, A. maculatus, and A. sinensis. It is probable that 
_ these are the commonest species of anopheles over the whole 
Archipelago. 
2. The results of this work and that of the work of Walker 
and Barber indicate that Anopheles febrifer and, to a less ex- 
tent, A. maculatus are the chief transmitters of malaria in the 
Philippines. 
3. Anopheles febrifer is a stream breeder widely distributed 
and often occurring abundantly in the breeding places. It seeks 
houses and readily bites human beings. 
4, The distribution of malaria in the Philippines, as indicated 
by nearly 7,000 examinations of spleen or blood of school 
children, is by no means universal but is most abundant in 
