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of second posterior cell, a small patch of yellowish-white scales on first vein before 
its middle and another at its apex, the latter spot encroaching upon the costal 
vein. Length, 3-5 mm. 
It would have been of considerable interest to determine the susceptibility of 
A eisetii and A. cruzii to malaria on account of their peculiar tree-living habits, but 
it was almost impossible to obtain larvae of those species; and among hundreds of 
Anophelines caught within quarters and barracks which were examined and 
dissected, no specimens of this species were ever seen. It is extremely unlikely 
that they play any part whatever in the transmission of malarial fever in the 
Canal Zone at this time. The larvae of these species proved extremely interesting 
in comparison with the commoner species, such as Ce. albimana, A. fscudofuncti- 
fennis and Arr. ( ?) malefactor, the anatomical characters of the former indicating 
definitely a very marked alteration in habits. 
COLLECTION OF LARVAE 
In order that a large number of adults could be kept on hand 
from day to day, it was arranged that sanitary inspectors at the 
various districts along the Panama Railroad should send bottles 
containing larvae and pupae to the laboratory daily. Special 
collections of larvae were also made and excursions to breeding 
places made from time to time. Upon receiving them at the 
laboratory, larvae were transferred to a glass moist jar partly filled 
with fresh water. Predaceous larvae, such as dragon-fly larvae 
were removed or killed and the Anopheline larvae transferred to 
leeding tanks containing algae and organic debris. These glass 
breeding tanks were placed on a table in front of a window having 
an eastern exposure so that they got direct sunlight for a few hours 
in the morning. 1 he water in the breeding tanks was kept fresh and 
free from fouling by passing a jet of air through it with a Pacquelin 
cautery bulb, having a heavy glass perforated tip. This proved to 
be a very important addition to the technique of breeding out larvae. 
P or shade and shelter a few Lemma plants were placed in the tank. 
Several writers, collectors, and malarial investigators have 
mentioned the difficulties attendant upon the breeding out of 
Anopheles mosquitos from ova or very young larvae. Others have 
not mentioned the difficulties encountered or have not described the 
means used to obviate them. Banks, in the Philippine Journal of 
cience, Vol. II, No. 6, December, 1907, states, ‘In laboratory 
breeding experiments the plants in the water begin to die within 
