158 
MALARIA 
for man ( androphilic ) or animals (zoo- 
philic). We can present only the data that 
are available. At the present time there 
have been recognized the following species 
of Anopheles: barberi Coq., boydi Vargas 
(Ifranciscanus McCracken), crucians cru¬ 
cians King, crucians bradleyi King, cru¬ 
cians georgianus King, quadrimaculatus 
Say, punctipennis Say, pseudopunctipennis 
Theo., atropos D. & K., walkeri Theo., occi- 
dentalis D. & K., occidentalis freeborni 
Aitken., albimanus Wied. 
All of these species have been infected 
experimentally with one, two or all three 
species of plasmodium of human malaria 
except A. boydi, A. crucians georgianus, A. 
occidentalis and A~ occidentalis freeborni. 1 
At the present time it is generally agreed 
that A. quadrimaculatus and A. occiden¬ 
talis and its varieties are the principal 
transmitters of human malaria in North 
America. That this assumption is correct 
seems doubtful to the writer. Only a few 
years ago we knew nothing about A. 
walkeri, yet today we know that it is widely 
distributed, that it readily and eagerly 
bites man and that it has been experi¬ 
mentally infected with tertian and aestivo- 
autumnal malaria. Recently it was found 
naturally infected with malarial sporo¬ 
zoites. Only a few years ago A. barberi 
was not found north of Washington, D. C., 
yet today it is recorded from many locali¬ 
ties despite its minute size and the difficul¬ 
ties of finding it. We know very little of 
its biology or its feeding habits; experi¬ 
mentally it has been shown to transmit ter¬ 
tian malaria from man to man. A. pseudo¬ 
punctipennis is known to transmit malaria 
in Mexico and Argentina, but our form 
appears to play no part in its transmission. 
More information is required about this 
species in the United States. 
The question before us is the role of 
anophelines in the epidemiology of malaria. 
From our present knowledge the following 
i Though Herms and Gray (1940) record this 
species as the transmitter of malaria in Calif, and 
N. Mex., I can find no data of either experimental 
infection or infected specimens caught in the wild, 
except the work of Barber and Forbrich (1933) 
(New Mexico, for A. maculipennis ). 
factors would seem to have to be present 
in order that an epidemic might occur in a 
known malarious region: (a) a susceptible 
population exposed to mosquito attack; 
(b) a new strain of malaria (either a 
heterologous strain or an increase in the 
virulence of the prevalent strain); (c) a 
species or subspecies of anophelines present 
and readily susceptible to infection and 
androphilous; (d) favorable breeding 
grounds for a marked increase of the 
anopheline transmitters; and (e) human 
carriers with viable gametocytes of a new 
strain (herologous) or an increase in the 
virulence of the prevailing strain. 
Early work, based on the mosquito- 
theory, was carried on by Doty (1901- 
1909) on Staten Island, and in some small 
towns near New York City by Berkeley 
(1901) where malaria occurred in epidemic 
form. Their work was very successful and 
malaria soon disappeared (in 1909 only 5 
cases on Staten Island). Probably the first 
city-wide organized malarial control in the 
United States took place at Ithaca, N. Y., 
beginning after an epidemic of typhoid in 
1903 and an epidemic of malaria in 1904, 
when there were over 2000 cases in a popu¬ 
lation of 13,000. The health officer was 
given authority to require every physician 
to report each week every case of malaria 
and its location, to require a blood examina¬ 
tion of every suspected case, to appoint an 
inspector and two assistants to find and 
eliminate anopheline breeding places, and 
to issue instructions as to how malaria is 
contracted, how to avoid infection and in 
regard to isolating patients. There were 
1000 cases in 1905; none in 1908, and since 
that time Ithaca has been practically free 
of malaria. 
In 1905, when Ithaca suffered from a 
severe flood, there were extensive cat-tail 
marshes in the northern, southern and 
western portions of the city in which 
Anopheles bred in immense numbers. 
Though A. punctipennis bred commonly 
about the city and still does, A. quadri¬ 
maculatus was recorded as the dominating 
and most prevalent form. Beginning in 
1905 and continuing until 1912, all these 
