—— ee FY 
524 
Mosquitoes of the genus Anopheles are at certain times numerous while at 
others they are not to be found. During the latter portion of the rainy 
season the Anopheles begin to multiply, reaching their maximum during 
the months of November and December. This coincides with the increase 
in malarial infections at this post, as is shown in the following table: 
Number Number 
Month, of infee- Month. of infee- 
tions. tions. 
1904. 1905—continued. 
ROUND wcantidteduct stent 24 || April ___ 10 
BODUIMDG occas idan enecienen 57 || May 2 14 
ss | ere Se pe a 4 Il PUNG..nccccnucapkataadiice 17 
OV GIG cn lieidnnticdince 66} duly 2.2... db ees ll 
DOOCRDOE caeccntcdiwennss 76 fh ADRURL 5... Lak clea 29 
1905. September____._..-__. 31 
January 76 Qoto Pele nn chittekebawsen 43 
February ____-------------- 97 November 54 
Oa 20 December 126 
During the five months in which I was stationed at Camp Stotsenberg I observed 
386 cases of malaria in the blood of which I was able to demonstrate the parasite. 
Of these, 248 occurred in Americans and 138 in natives. As regards the type of 
infection, 98 were infected with the tertian plasmodium, of which 63 were Amer- 
icans and 35 natives; 8 with the quartan, of which 2 were Americans and 
6 natives; and 272 with the estivo-autumnal plasmodium, 183 being Americans 
and 89 natives. Of the «stivo-autumnal infections, 258 were due to the tertian 
estivo-autumnal plasmodium and 14 to the quotidian variety. There were 8 com- 
bined infections with the tertian and the estivo-autumnal-tertian plasmodium. 
The following table illustrates the character of the infections as regards their 
initial attacks: 
Initial attacks, 227; in Americans, 227; in natives, 0. 
Recurrent attacks, 38; in Americans, 18; in natives, 20. 
Latent infections, 115; all in natives. 
From a consideration of the data given above, several points of interest 
may be noted. 
1. In regard to the type of plasmodium present, all varieties of malarial 
infection occur at Camp Stotsenberg, the westivo-autumnal ones being the 
most numerous, the tertian next, and the quartan infections rare. 
In the past there has been considerable discussion regarding which types 
of malarial infection were the most prevalent in the Philippines, and I 
have always maintained that here, as in almost all tropical regions, the 
eestivo-autumnal fevers are the commonest and certainly my studies at 
Camp Stotsenberg have only confirmed my belief. However, it must 
be admitted that the type of infection present in one locality can not 
be considered as a criterion in judging of that to be found in another. 
This is well shown by the fact that at Camp Gregg, 50 miles north 
of Stotsenberg, the prevailing malarial infections are tertian in character. 
