X,B,3 Barber et al.: Malaria in the Philippines 243 
unable to find more than one or two larve after considerable 
search. We found that the foreman of the camp had been using 
moderate amounts of crude carbolic acid in this stream. We 
could find no malaria in the camp, and there were few mos- 
quitoes about. 
A large proportion of laborers recruited from the large centers 
of population in the Philippines are undoubtedly little infected 
at the start, and as experience has shown they offer little or no 
resistance to the disease. When brought into construction camps 
they have suffered severely with malaria. Once well infected 
it is difficult to eradicate the epidemic in the camp, and as such 
populations are rarely permanent, gamete carriers are spread 
throughout the country. The supervision of such camps and 
the prevention of malaria in them becomes a matter of general 
as well as of local importance. 
We have had no opportunity of judging the success of quinine ~ 
prophylaxis in any locality in the Philippines except at the Iwahig 
penal colony in Palawan, where 5 grains of quinine per day are 
given to each colonist. The amount of acute and latent malaria 
in this colony and the results of the mosquito survey there are 
given in Table IV and the accompanying text. Since anopheles 
mosquitoes are abundant there and the region is very malarious, 
it is probable that the prevalence of malaria in the colony is 
materially reduced by the prophylaxis, but as the data show it 
is by no means wholly prevented. Quinine prophylaxis is gen- 
erally considered advisable only as a temporary measure or in 
an intensely malarious region where more permanent antimala- 
rial means are impracticable. 
Measures have already been taken by the Bureau of Health 
by which quinine is made available to people in many localities 
at comparatively little cost. Such measures are not only of the 
greatest value in curing the sick, but the number of gamete 
carriers is undoubtedly reduced. It is difficult, however, to get 
people to follow a quinine treatment persistently enough to get 
rid of latent malaria and consequently of the gametes of the 
parasite, and many probably do not take quinine at all. There- 
fore, in order to get permanent results, the distribution of quinine 
should be supplemented by measures for the prevention of the 
transmission of the disease. 
Bed nets, efficacious where intelligently used, are not to be 
relied on for an ignorant population, as shown by the results of 
the mosquito survey at Iwahig where many anopheles were 
found inside of badly adjusted nets. Many people in the Islands 
