INSECTS IN RELATION TO OTHER ANIMALS 208 
himself to be bitten by the insects. Though previously free 
from the malarial organism, he contracted a well-marked 
infection as the result of the inoculation. 
Furthermore, it 1s highly probable that malaria cannot be 
transmitted to man except through the agency of the mos- 
quito. This appears from the oft-cited experiment of Doc- 
tors Sambon and Low on the Roman Campagna, a_ place 
notorious for malaria. There the experimenters lived during 
the malarial season of 1900, freely exposed to the emanations 
of the marsh and taking no precautions except to screen 
their house carefully against mosquitoes and to retire indoors 
before the insects appeared in the evening. Simply by ex- 
cluding Anopheles mosquitoes, with which the Campagna 
swarmed, these investigators remained perfectly immune from 
the malaria which was ravaging the vicinity. 
In a later experiment on the island of Formosa, one com- 
pany of Japanese soldiers was protected from mosquitoes and 
suffered no malaria, while a second and unproteeted company 
contracted the disease. 
The evident preventive measures to be taken against ma- 
laria are (1) the avoidance of mosquito bites, by means of 
screens, and washes of eucalyptus oil, camphor, oil of penny- 
FOval, ‘Oil Of tar, etc, applied to exposed parts:ot the body; 
(2) the isolation of malarial patients from mosquitoes, 1n 
order to prevent infection; (3) the destruction of mosquitoes 
-in their breeding places, especially by the use of kerosene and 
by drainage. During unavoidable exposure in malarious 
regions, quinine should be taken in doses of six to ten grains 
during the day at intervals of four or five days (Sternberg). 
Culex and Anopheles.—The mosquitoes of North America 
number one hundred and twenty-five known species. Of these 
only the genus Anopheles transmits malaria to man, though in 
India, Ross found that Culev transmits a form of malaria to 
sparrows. These two common genera are easily distinguish- 
able. In Culex the wings are clear; in Anopheles they .are 
spotted with brown. In Culex when resting, the axis of the 
