﻿IX, B, 5 Walker and Barber: Malaria in the Philippines 433 



INFECTION OF THE SALIVARY GLANDS 



Of the 332 mosquitoes in which the salivary glands were dis- 

 sected out for the determination of infection, 21, or 6.32 per 

 cent, contained sporozoites. The total percentage of infected 

 salivary glands is of no particular significance, as it depends 

 upon the time elapsing between the meal of infective blood 

 and the date of dissection and upon the species of anopheline. 

 Therefore, the distribution of the mosquitoes dissected for 

 the salivary glands and the percentages infected are classi- 

 fied in Table XIII according to the species and to the time of 

 development. 



Table XIII. — Infected salivary glands. 



Species. 



Anopheles febrifer: 



Dissected 



Infected — 



Number _. 



Per cent 



Anopheles rossii: 



Dissected 



Infected — 



Number 



Per cent 



Anopheles barbirostris: 



Dissected 



Infected — 



Number 



Per cent 



Anopheles sinensis: 



Dissected 



Infected — 



Number 



Per cent 



Anopheles macidatus: 



Dissected 



Infected — 



Number 



Per cent 



Days after infective feeding. 



10 



11 







12 



21 



3 

 14.28 



32 





 



13 



13 



1 



1100.00 



14 



3 



21.42 



54 



14 



13 



15 



15 



2 

 13. 33 



10 



22 



16 



37 



6 



16.21 



16 



18 



Total. 



11 111 



20 



54.54 :18.01 



125 



75 



21 



1 



4.76 



The earliest day after the infective meal of blood that sporo- 

 zoites were found in the salivary glands was the twelfth, in 

 both Anopheles febrifer and in Anopheles maculatus infected 

 with Plasmodium prsecox (falciparum), the parasite of sub- 

 tertian malaria. These infections were found during the warm 

 season; in the cool season the period of development of the 



