X, B, 8 Barber et al.: Malaria in the Philippines 185 
With regard to the avidity for human blood and the habit of 
house visiting of anopheles under natural conditions, we have 
data from two localities: namely, the San Jose Estate, Mindoro, 
and the Iwahig penal colony, Palawan. 
The region occupied by the San Jose Sugar Estate is com- 
paratively flat and not much above sea level. It was formerly 
covered with cogon grass. Some three years ago it was noted 
for a very large amount of malaria with a high mortality, but 
at the present time very severe cases are few and the mortality 
from malaria is almost nil. Latent malaria is still present to 
a considerable degree, as shown by the figures in Table I. 
Barber spent the month of May, 1914, on the estate, and during 
this time a squad of assistants made visits almost daily to houses 
belonging to the estate for the purpose of catching mosquitoes, 
especially anopheles. The mosquitoes were caught in test tubes 
or by means of nets of gauze or cobweb and were brought fresh, . 
often living, into the laboratory for identification. Dr. G. W. 
Daywalt, resident physician of the estate, has for many months 
kept mosquito catchers employed on the estate, and he ascribes 
much of the diminution of malaria to this part of the work. He 
kindly put at our disposal his squad of trained mosquito catchers 
to assist our own employees. We take this opportunity of ac- 
knowledging this and other courtesies shown us by Doctor Day- 
walt during our visit to the estate. 
The results of the mosquito catching are given by barrios 
in Table I. The number of days on which mosquitoes were 
caught, 25 in all, are given for each barrio. When morning 
and afternoon visits were made on the same day to a given local- 
ity the two visits are recorded as one. 
It is seen that the ratio of Anopheles febrifer to A. rossi varies 
greatly in different barrios. ‘Two barrios, “J” and Magbando, 
show a relatively large number of A. febrifer. Barrio “J” was 
at that time a small barrio of only seven or eight houses. It 
is comparatively new and is situated about 2 kilometers from the 
center of population of the estate. There was a minor outbreak 
of malaria in this barrio earlier in the season, and the general 
locality has in the past been notably malarious. Larve of 
A. febrifer were found by us in moderate numbers in a ditch fed 
by the seepage from an irrigation canal near this barrio, and they 
also occurred in small numbers in grass at the edge of the very 
swift water of the canal itself. They were abundant in a brook 
flowing through a wooded swamp less than half a kilometer 
distant. Some oiling of the seepage ditch near the barrio had 
been done, but little or none was done farther up this ditch or 
