The Nuptial Flight 91 
tance in the same direction, and liberated at 10:15; at 11:25 it 
returned again. The temperature was now falling; the large 
number of park lights which the moth had to pass seemed to 
exert no disconcerting influence. 
Exp. 6. May 7. Wind, same; station, 11/6 mile east. Once 
more this weary moth was taken out to a more distant point 
in the same direction, and liberated at 11:50 p. m., but it never 
came back. The temperature fell low that night, with rain and 
Snow, so we must abandon the experiment without knowing 
Whether exhaustion, lack of odor perception, adverse weather 
conditions or the presence of some other female elsewhere caused 
the failure of this moth to return. Later tests proved that both 
rain storms and greater distances than this may be surmounted 
by these creatures. 
Exp. 7. May 14. Four females of various ages had been 
kept at the windows for several days, and this morning 7 young 
native males were found in the room. 
Exp. 8. May 15. While the east windows were closed, 12 
native males flew in during the night through the west windows. 
However, they did not remain in the west room, but moved to 
the east room, probably attracted by the light rays of dawn 
more than by the odor of the females, for all were at rest on 
the window sash, instead of the cages on the table. Judging 
from the perfect condition of the wings, all were quite young. 
Exp. 9. May 16. Since May 14 and 15 had given us 19 
wild males, and I was in need of more material, I made special 
effort to get them by opening all the windows and placing to 
advantage (in relation to wind) my best females. But none 
came during that night. This inactivity may well be attributed 
to the low temperature, which was only 50° F., between 1 and 4 
a.m. We know from earlier investigations* that a low tem- 
Perature retards the activity of these creatures and, by conserv- 
ing their stored energy, which cannot be replaced, prolongs their 
ife. Heavy rains and thunderstorms oceurred during the night 
also, but on other oceasions these elements did not deter the 
a in their flights when temperature conditions were favor- 
able. 
Exp. 10. May 17. With the thermometer fluctuating be- 
—— ones 
“Trans. Acad. Sci. St. Louis. 23: No. 1, 1914. 
