The Nuptial Plight 125 
were set free at five minutes before midnight and sat down with- 
out even trying to come in that night? It is surprising that out 
of the 5 experienced fliers, two returned, while of the very 
young ones 8 came in. It seems to me that this experiment 
shows clearly that the one direction is far more favorable for 
the return of the moths than the other; if it is not the motion 
of the air that creates this response from a certain direction, 
then what is it? 
Exp. 15. June 17. Wind, southeast; station, 1% miles 
northwest. Twenty-six eynthias, 6 of which were 1% days old 
and 20 were less than one day old, were liberated near the path 
of the wind at a distance of 11% miles, at 10:52 p. m. Only one 
returned, aged 114 days, after a flight of 124 hours. 
Exp. 16. June 17. Wind, southwest; station, 34 mile north- 
west. Nineteen males, less than one day old, were set free at 
1l p.m. None of these returned. This lot was liberated in an 
ailanthus bush; this is the food plant of the caterpillars, and 
the insects upon emerging throw off the peculiar odor of this 
. tree; hence it might be that the odor of this tree had something 
to do with diverting their attention or confusing them. 
Exp. 17. June 17. Wind, southeast; station, 214 miles 
northwest. Twenty moths, 114 days old, were liberated in 
Forest Park at 11:25 p. m. Two returned from this flight of 
21 miles, one after only an hour and the other 41% hours. 
Exp. 18. June 17. Wind, southeast; station, 2 miles north. 
Twenty male eynthias, aged 1144 days, were taken to a point 
north, in Forest Park, at 11:35 p. m. One returned the same 
night, after 2 hours, and another did so the next night. 
Exp. 19. June 17. Wind, southeast; station, 1/5 mile 
northwest. For this experiment, all the cynthia moths on hand 
Were used. They were all held captive after having returned 
from previous flights, and their ages were as follows: 2 days 
old, 19; 8 days old, 2; 4 days old, 2; 17 days old, 2. These 25 
Were taken out a short distance, 1/5 mile, in the general diree- 
tion toward which the wind was blowing, at 11:50 p. m. Eight 
of this lot returned, the first after only five minutes and the 
last after two hours and six minutes. All of these eight were 
two days old, but, of course, these predominated in the lot. 
Exp. 20. June 20. Wind, southeast, station, 114 mile west. 
