1915] Behavior of Anopheles 241 
added buoyancy reduces the muscular effort needed to reach 
the surface, and probably reduces the mortality due to fatigue 
among the larve. 
At the laboratory, larve of A. tarsimaculata taken from 
fresh water were transferred into a pan containing saline water 
from the marsh. This produced intense stimulation and a 
large mortality resulted. Pupation was accelerated among 
mature larve. The adults that emerged were placed into a 
large cage containing a plate of fresh water and a plate of salt 
water, both from actual habitats. <A liberal blood meal was 
given. Eggs were found only in the plate with fresh water. 
Continuing the experiment, but using pupe collected at the 
salt marsh habitat, eggs were deposited in both salt and fresh 
water. There appears to be a natural selection as to water 
suitable for oviposition, and in nature such must be the case, 
for many bodies of water are encountered which appear excel- 
lent breeding areas, yet are found wholly devoid of larve. At 
the same time the entire surrounding territory may be literally 
alive with Anophelenes. When very young larve are thrust 
into saline water, attunement to the rapid change is quicker 
than when older larve are so treated. 
The general belief is that Anopheles will not breed in salt 
water. This is because the average observer fails to learn that 
the genus Anopheles contains a large number of species which 
can be grouped into several very distinct sections. The 
chances are if all Anophelenes bred in the same kind of waters, 
we would have a far fewer number of species. 
DeVogel (1907) found a species of Anopheles breeding in a 
pool containing 2.8% of NaCl; and after considerable study, he 
arrived at the conclusion that the eggs of species which can live 
very well in sea-water, develop in such water even when evap- 
orated to one-half its original bulk, but that the larve do not 
appear to transform to adults if the concentration exceeded 
33% of the original quantity. This in the main part is also 
true of A. tarsimaculata on the Canal Zone. Banks (1908) 
found Anopheles ludlowii Theob. breeding in both salt and fresh 
water, quite like tarstmaculata. Howard, Dyar and Knab 
(1913) criticize Banks’ work as inconclusive and believe his 
fresh-water ludlowti was none other than A. rosiz, and there is 
ample room for such doubt since determinations were made 
only from larvee—a difficult task. 
