140 Trans. Acad. Sct. of St. Louis 
mined by rhythmic activity or by light stimuli (moonlight and 
dawn) cannot yet be determined. 
Exp. 11. May 30. Wind, east; station, 14 mile east. Three 
native males which had come in at dawn were liberated at 9 
p. m. in this unfavorable wind; none returned. 
Exp. 12. May 30. The moon shone all night, and the wild 
moths came in at the following hours: one each at 11:00, 11:40, 
11:55, 12:01; 12:05 and 3:15. Here again their activity is 
centered in the two periods, the midnight and the dawn hour. 
Exp. 13. June 1. One more wild male came in at dawn 
with the cecropias. 
Exp. 14. June 1. The moon that night was half obscured 
in a haze. One native polyphemus came in at 11:45, and 8 more 
during the dawn hour. This, added to the evidence of previ- 
ous nights, certainly indicates two periods of activity in the 
night, the same as the sister species. The wind was blowing from 
the south, and all these moths came in from the north. 
Exp. 15. June 6. During the dawn, one native wild poly- 
phemus flew to the roof. There were 6 cages of female 
ceeropias there, but no polyphemus; the only females of their 
own species in our possession at the time were on a table inside 
the laboratory. The arriving male spent no time on the roof, 
but flew in at the open window and went directly to the cage 
of females of his own species on the table. 
Exp. 16. June 10. One native polyphemus came in at 
dawn. 
Exp. 17. June 15. Wind, imperceptible; station, 4 mile 
north. The 8 bred males used in this test were 4, 2, 1 and % 
days old. They were liberated at 10:58 p.m. Only one of these 
returned ; it was 2 days old and came in with the cecropias the 
following dawn. 
Exp. 18. June 18. Despite the fact that the female poly- 
phemus had been displayed constantly, since June 10 no native 
males had come in until this morning when at 2:20 one came 
and alighted on the cage. There were cages of female cynthias 
all about, but this male made no mistake in his selection. This 
is probably the end of the polyphemus season. 
