14 The Philippine Journal of Science 



Table V. — Controlled series. Dissections according to gamete carriers 



1918 



Species of Anopheles. 



Crescents only. 



Benign tertian 

 only. 



Benign tertian 

 plus crescents. 



Benign tertian 



plus quartan 



plus crescents. 



Dis- 

 sected. 



Pos- 

 itive. 



Dis- 

 sected. 



Pos- 

 itive. 



Dis- 

 sected. 



Pos- 

 itive. 



Dis- 

 sected. 



Pos- 

 itive. 





61 



101 



73 



42 



113 



159 



160 

 117 

 82 

 21 



5 

 18 



4 



5 

 12 



3 



P. cent. 

 65.6 

 29.7 

 11.0 

 4.8 

 32.7 

 28.3 



15. 6 

 16.2 



0.0 

 0.0 

 20.0 

 50.0 

 75.0 

 100.0 

 83.3 

 33.3 



8 

 28 



P. cent. 

 25.0 

 3.6 





P. cent. 





P. cent.. 



A. indcfinitus, brackish water . 



A. indefinitus, "known" 



A. indefinitus, "probable" 













n 



0.0 





























Type Giles, "probable" . 



Type Giles and indefinitus. 

























i 





8 







0.0 



18 



33.3 

 20.0 







A. barbirostris 





10 



15 

 8 



6.7 

 12.6 













3 



0.0 





2 



0.0 









2 

 5 

 2 

 6 



50.0 











40.0 



0.0 



40.0 





















1 



0.0 



Total 







976 



24.1 



46 



6.5 



67 



22.8 



24 



8.8 





It will be noted in Table V that the majority of the carriers 

 harbored crescents. Where two sorts of gametes occurred in 

 one or more carriers in the course of a feeding experiment, there 

 was in most cases doubt as to which kind of parasite infected 

 the mosquitoes. However, in the case of barbirostris exposed 

 to three carriers having different kinds of parasites, it seems 

 clear that the mosquito found infected was infected with benign 

 tertian. Well-formed sporozoites were present in the oocysts 

 in the gut. Only six days intervened between exposure to the 

 quartan carrier and dissection, and only four days intervened 

 in the case of the crescent carrier, periods of time too short 

 for the formation of sporozoites. So it is at least highly prob- 

 able that the effective gamete was from the benign-tertian 

 carrier in which the interval between feeding and dissection 

 was eight days. In the case of the single positive dissection 

 in sinensis the evidence is less clear, but it is highly probable 

 that the single positive mosquito found was infected with sub- 

 tertian. Only two small oocysts were found in the gut, these 

 apparently not over 6 days old (measurement 22.1 and 30.6 

 microns in diameter, respectively), and ten days had elapsed 

 since the last exposure to a benign-tertian or to a quartan 



