SOME FACTS ABOUT MALARIA, 9 
In such a locality, therefore, the infection is constantly passed on 
by means of the mosquitoes from the older children or from adults to 
the newly born infants, so that the locality may remain malarious for 
very many years, in fact indefinitely. 
In the same way a newcomer arriving in such a locality will very 
probably become infected, especially if he sleeps in an infected house, 
even for one night, at a time when mosquitoes are flying and biting. 
A locality is malarious only when it contains persons infected with 
the parasites, and also sufficient numbers of the proper species of 
mosquitoes to carry the infection to the healthy persons. 
Fic. 1.—Anopheles quadrimaculatus: Male and female mosquitoes. Greatly enlarged. 
(Original. ) 
THE MALARIAL MOSQUITOES. 
There are in the United States only three species of mosquitoes 
which commonly carry malaria, namely, Anopheles quadrimaculatus 
Say, Anopheles crucians Wied., and Anopheles punctipennis Say. 
Several other species of Anopheles are occasionally found, but are not 
important malarial factors, 
Anopheles quadrimacylatus (figs. 1, 4, 5, 6) is commonly found in 
the more Northern States, and A. crucians (fig. 2) more abundantly 
in the Southern States, particularly in the coastal region. 
A. punctipennis (fig. 8) occurs in both Northern and Southern 
States. It has been found to carry quartan and tertian malaria in 
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