It is concluded from this series of experiments that 
Ce. albimana, the common white hind-footed mosquito-a, 
extremely hardy, rapidly developing, adaptable mosquito-is the 
transmitter of malignant tertian and of simple tertian malarial fever 
m the Canal Zone at this time. Specimens of this species infected 
with simple tertian parasites became infective between nine and 
eleven and a half days after the first feeding. When infected bv 
ma ignant tertian parasites, sporozoites appeared in the salivary 
g ands as early as the eleventh day in some mosquitos, and later 
than twelve and a half days in others. 
Ce. (?) tarsimaculata appears to be as susceptible to the 
malignant tertian parasite as Ce. albimana , and no doubt if a 
favourable opportunity had presented it would have been found 
tertian matoi wouId have b <*n equally susceptible to 
transmi ^' “^°( nnct ‘^ enr,is ’ s only slightly concerned in the 
onwT , f “ a ! anaI fever ' if at aiI > not only fmm the fact that 
condit • r T ° f 1,rty '° ne “osquitos under the most favourable 
rela^7 S f mfeCted - but fron > additional fact that 
relatively few specimens are taken in quarters at this time. 
malaria, f 7"" ‘ S not concerned in the transmission of 
malarial fever in the Canal Zone at this time. 
showed development m o f SqUlt ° S maIariaI 2 yg° tes . rented 
tSilKUS. A fc " “ 
species bit and fa bl,,n&s, l e - whe re mosquitos of any of the 
of ova • and to t 'l !° h . eC ° me infect «i, twenty showed development 
Ce (?) Zrl ; hC kn ° Wn species, aitJne and 
•J&srss- szr : “ t -> * ™ 
development of ova. ^ become infect ed six showed 
ova are not necessarv ’ f 3P ^ ar tbat fecundation and development of 
Under the most appare^ ^ Zyg ° te5 ' 
out of the lot of susceotihlcv , ourable circumstances one or two 
and these, no doubt p OS s * n ° P lebnes w ’d fail to become infected, 
parasite. ss ess an active immunity toward the malarial 
