204 MOSQUITOES OF NORTH AMERICA 
Kinoshita states further that Anopheles listoni does not occur in Japan and 
that the country has always been free from pernicious malaria in spite of the 
fact that persons suffering with pernicious malaria frequently come to Japan. 
On the other hand, Kinoshita found that both in Formosa and Japan Anopheles 
sinensis is the principal transmitter of tertian malaria. By experimentation 
he found that about 50 per cent of this species became infected with tertian 
parasites; quartan parasites developed in this mosquito only at low tempera- 
tures and the parasites of pernicious malaria never. Another interesting point 
in this connection is that he not rarely found new infections of tertian malaria 
in winter, while this was not the case with pernicious malaria. The explanation 
lies in the fact that in Formosa Anopheles sinensis is active throughout the 
winter. 
It will thus be seen that negative results with a given species of Anopheles 
are not conclusive unless the experiments are conducted with all types of malaria 
and under the most favorable conditions. Furthermore it would appear that 
different species of Anopheles, where susceptible to the same types of malaria, 
may be so in different degrees. Grassi, Bignami and Bastianelli, in their early 
experiments, had found that a certain proportion of the Anopheles appeared to 
be naturally immune and failed to develop the malaria parasite, even under the 
most favorable conditions. This proved to be the case with all the species of 
Anopheles and of parasites experimented upon by them. 
In a recent paper Dr. Samuel T. Darling discusses the relation of the various 
species of Anopheles to malaria in the Panama Canal Zone. His careful studies 
show that Anopheles albimanus is the principal transmitter of malaria, both 
wstivo-autumnal and tertian, in that region. He found that 70.8 per cent of 
the individuals of this species which he induced to bite malarial patients became 
infected. He also found that this was the species which frequented houses most, 
constituting in Ancon, during October, 1908, 72.5 per cent of the Anopheles 
found, and in some villages being the only species present. Of Anopheles 
pseudopunctipennis it was found that 12.9 per cent of the individuals experi- 
mented with became infected, while of 17 A. malefactor none became infected. 
Anopheles argyritarsis and A. tarsimaculata were later found by him to be 
malaria transmitters. 
The brothers Sergent have recently found sporozoits, probably malarial, in 
the salivary glands of Anopheles algeriensis and A. hispaniola in Algeria. In 
addition to the malaria-bearing forms above mentioned, Theobald in the fourth 
volume of his monograph lists Anopheles barbirostris, A. pseudopictus and A. 
theobaldi as transmitters of the malarial parasites. 
THE HABITS OF ANOPHELES MOSQUITOES. 
The general points of difference between adults of this group and those of 
other mosquitoes are very well understood, the long palpi of the female as con- 
trasted with the short palpi of the females of most other mosquitoes, for example. 
The other points of difference will appear from the systematic descriptions. 
