X, B, 38 Barber et al.: Malaria in the Philippines 233 
occurred in the immediate neighborhood of a malarious barrio. 
In both localities A. febrifer was also found. However, A. macu- 
latus is relatively scarce, and probably plays a far less part in 
the transmission of malaria than A. febrifer.: 
Watson * believes that A. maculatus (= A. wilmori) is the 
chief carrier in certain hill regions of the Federated Malay 
States. He reports this species from a Dutch island off Singa- 
pore, where malaria is intense, and from Hongkong. In any 
case, antimalarial measures directed against A. febrifer would 
be equally efficacious against A. maculatus, which has similar 
habits. 
In general, the highest indexes of malaria have been found 
in well-watered, but not necessarily swampy regions; and small 
clear streams, especially where in close proximity to houses, 
offer more danger than swamps, lakes, or wholly stagnant 
water. 
SEASONAL INDEX OF MALARIA 
From information obtained locally in malarious towns re- 
garding the worst ‘‘fever’” months, it would appear that March, 
April, and May, in the hot dry season, are most free from mala- 
ria, but the evidence is not without contradictions. For the rest 
of the year the information obtained varied widely in different 
localities, but the rainy season and the cooler dry months were 
more often mentioned as malarious. Where the number of latent 
cases is large, we would expect a proportion of these cases 
to become acute at times when there is the most exposure to 
weather—the rainy season and the cool season, when the nights 
are often decidedly chilly and thinly clad people suffer from cold. 
As shown in Table VI, towns examined twice give a percentage 
of positives obtained during the hot dry season lower in nearly 
every case than that obtained between July and December 1. 
In some cases the slides obtained in the hot months were in 
poorer condition for examination, but making allowance for this 
there is still a lower percentage for the hot dry season. 
A very important matter in the epidemiology of malaria is 
the time of the year when most infections occur. This is a 
matter difficult to determine from statistics obtained from the 
indigenous population of a malarious district where a large 
percentage of the people harbor parasites the year around. 
Some information may be obtained from isolated epidemics 
* Trans. Soc. Trop. Med. & Hyg. (19138), 59. 
