22 
nation can be induced to bite malarial patients and prove efficient hosts 
for the infective sporozoites. This was indicated in a series of experi¬ 
ments made with some of the specimens collected at Talladega 
Springs. This occurred six weeks after they were subjected to the 
artificial conditions of the New Orleans laboratory. 
The results of dissecting 2,122 specimens of Anopheles in the 
Mississippi series have been reported in a previous paper. (Mitz- 
main, 1915.) 
A total of 1,211 specimens was dissected previous to May 15, after 
which time infected mosquitoes in nature were found. It is of course 
realized that this lot may possibly include individuals of the spring 
brood, but unless infections are involved it is found convenient to 
include them. In this connection it is pointed out that the oppor¬ 
tunity for receiving the initial infection favors the rejuvenated 
winter forms, which are the first to secure blood previous to egg lay¬ 
ing and the death of the brood. 
The 1,211 specimens were distributed as to species as follows: 
A. quadrimaculatus , 1,081 specimens. 
A . punctipennis , 97 specimens. 
A. crucians , 30 specimens. 
The remaining mosquitoes dissected during the month of May were 
used as indicators of the first appearance of the sporogonic cycle of 
the malaria parasite for this district. These included 902 specimens 
of A. qvwlrimaculatus and 9 specimens of A. punctipennis. None of 
the latter became infected, but 3 specimens of A. quadrimaculatus 
showed malaria organisms between May 15 and May 26. 
It has been previously stated that the occasional sporadic flight and 
consequent activity of Anopheles mosquitoes were witnessed early in 
the investigation during February 11-14. Upon the first day of the 
mosquito attacks the maximum temperature had risen 6.5° C.—from 
12.5° C. of the previous day to 19° C.—which rise continued for the 
three following days to a maximum of 21° C. 
When men and horses were exposed in the woods the biting ap¬ 
peared general without apparent host preference. House infestation 
was reported to be unusually severe, although complaints by the 
plantation negroes were not generally credited. Besides dissecting 
as many captured specimens as possible, during the intervals of col¬ 
lecting an effort was made to ascertain the pathogenic effect, if any, 
of the biting of the infesting Anopheles. Fifteen persons besides 
myself complained of the biting of mosquitoes upon this occasion, 
and the subsequent medical histories of these individuals were ac¬ 
curately followed for a period of four-five weeks. No case of clini¬ 
cal malaria developed in any of these persons; none of them was 
using quinine in any form. From this time, extending through 
March and April, four reliable observers, technically trained or col- 
