﻿IX, B, 5 



Walker and Barber: Malaria in the Philippines 431 



which at least one mosquito in the series became infected. The 

 fact that one mosquito in such a series became infected proved 

 that the gametes were capable of infecting. In Table XI are 

 given the total infections and the infections grouped according 

 to the above divisions, classified by species. 



Table XI. — Perceyitage of infected mosquitoes. 



Total dissected 



Total infected: 



Number 



Per cent 



Blooded females not separated from 

 empty females: 



Dissected 



Infected- 

 Number 



Per cent... __ 



Blooded emales only: 



Dissected 



Infected — 



Number _ _ 



Per cent 



Strictly comparative experiments: 



Dissected _ __ 



Infected — 



Number 



Per cent 



A.feb- 

 rifer. 



373 



132 

 35.38 



138 



24 

 17.39 



235 



108 

 45.95 



162 



108 

 66.66 



A. rossii. 



642 



63 

 9.81 



380 



28 

 7.36 



262 



35 

 13.35 



187 



35 

 18.71 



A. barbi- 

 rostris. 



205 



7 

 3.41 



93 



1 



1.07 



112 



6 

 5.35 



100 



6 

 6.0 



A. sinen- 

 sis. 



18 



18 



12 



A. mami- 

 latus. 



49 



3 

 6.12 



46 



1 



2.17 



2 

 66.66 



2 

 66.66 



Total. 



1,287 



205 

 15.92 



657 



64 

 8.21 



630 



151 

 23.96 



464 



151 

 32.54 



In the last section of Table XI, the experiments with the 

 several species are strictly comparable and the results give 

 a more accurate measure of the susceptibility of the first three 

 species. In the last two species the number of individuals 

 included in the data is insufficient to draw reliable conclusions. 



In 1910 de Vogel was able to infect "Myzomyia rossii" breeding 

 in brackish or salt water, but not those breeding in fresh water. 

 Banks (1907) also obtained infections of "Myzomyia ludlowii" 

 breeding in brackish and salt water, but he made no experi- 

 ments with those breeding in fresh water. As our experiments 

 were made with Anopheles rossii breeding in both fresh and 

 salt water, it is interesting to compare the susceptibility of the 

 mosquitoes from the two sources. Five hundred ninety-five 

 specimens of Anopheles rossii breeding in fresh water were dis- 

 sected, of which 58, or 9.74 per cent, were infected; 42 speci- 

 mens of Anopheles rossii which were bred in salt water were 

 dissected, of which 5, or 10.63 per cent, were infected. There- 



