272 MOSQUITOES OF NORTH AMERICA 
Otto and Neumann have made experiments on the resistance of the adult 
Aédes calopus to cold. These were made in Germany, with imagos bred in con- 
finement. When calopus were placed outside the window with the temperature 
at the freezing point they died very quickly. When exposed to a temperature of 
4° ©. (39° F.) for one hour and then returned to the warm room they could 
still be revived, but longer exposure killed them. However, calopus can survive 
cool temperatures for a considerable time. Carter states that “ Guiteras placed 
thirty-three mosquitoes in an ice-box at 46.5° to 50° F., without food or water ; 
three of them survived to the eighty-seventh day, when they were eaten by ants.” 
Otto and Neumann, in a similar experiment, with a constant temperature of 
7° to 8° C. (45.5°-48° F.) kept calopus alive to the eighty-second day. In this 
experiment they employed 25 male and 25 female mosquitoes; they were fed 
with sugar, honey and water, and part of the females had sucked blood. Ina 
short time the insects became stiff and only moved very slowly; they nearly 
always sat on the bottom of the jar, es if they could no longer retain their hold 
on the glass sides. After three days fcur of the males died and none of the re- 
maining 21 males survived the fifteenth day. On the contrary but very few of 
the females died in the first two weeks and after 30 days about half of them still 
remained alive; on the fiftieth day three were alive; after 61 days but two, and 
after 71 days only one remained. 
THE BITING OF CADAVERS. 
An interesting observation made by Rosenau, Francis and Goldberger (Report 
of Working Party No. 2) indicates that the yellow-fever mosquito may bite a 
cadaver, and, if on a dependent portion, can draw blood. The two observations 
made on this point were as follows: 
“ Narciso Nadal (Case XX). A number of Stegomyie were applied twelve 
hours after death, only one of which apparently obtained blood. 
“Trinidad Martinez (Case XXII). A number of female Stegomyie fasciate 
were applied one-half hour after death, and three insects succeeded in feeding 
with blood.” 
These authors point out that, as the work of the French commission has shown 
that the blood of yellow-fever patients is not infective after the third day, the 
danger of the carriage of infection by mosquitoes which have fed upon cadavers 
must be very remote. The only chance of infection from such a source would 
be in the case of the death of the patient within the first three days. 
DISTANCE. OF FLIGHT. 
The distance of flight of the adult is a very important question. Calopus 
seems to be a strong flier, as is evidenced by a series of experiments carried on 
by Goeldi on the effect of a strong current of wind between two open windows, 
or by air currents produced by a mechanical ventilator. He found that calopus 
pays absolutely no attention to such currents, continuing its evolutions about 
him and stinging precisely as though the air current made no difference to it. 
This indicates that calopus would not easily be carried involuntarily by the 
wind. Opposed to these assertions of Goeldi are the observations of Otto and 
