254 Annals Entomological Society of America {[Vol. VIII, 
b. Demonstration of Flight. 
I, The Staining and Recovery of Marked Mosquitos: In 
his previous paper (1913-a) the writer devoted considerable 
space to the need-of collecting large quantities of larve and pupz 
and how these should be treated to yield a maximum amount 
of adults. At that time this was the only way adult mosquitos 
could be had in sufficiently large numbers. At Gatun, as 
already stated, the conditions met with presented a great 
improvement over this tedious and often disappointing method. 
ML 
GATUN CZ 
OLD 
\ #4 “/ FRENCH ca NAL | BREED! KG THE LE PRINCE EXPERIMENT 
f AREA | 
iv 
e 
HYDRAULIC FILL a 
The Anophelenes and Aedes teniorhynchus were so prolific 
that several thousand could be trapped within an hour. The 
special advantages of this, aside from the saving of time and 
expense, were, (1), that the adults matured in their natural 
environment and not in breeding cages; (2) they were an 
integral part of the hordes which would begin that same night 
their hasty journey to Gatun; (3) they were caught the same 
late afternoon they were to be liberated and could be set free 
at the exact moment that the flight began. The only unnatural 
feature was the addition of the tiny speck of anilin dye, but this 
can hardly produce much inconvenience to the mosquito since 
the spray used was extremely fine. If the spray had been very 
coarse and prolonged, it is easy to see how the speck of dye 
would cause mechanical irritation. 
