Experiments in Rhythmetic Periodicity 187 
in room. Fifty-three males were placed on the south wall, and 
on the floor a few feet in front of them was placed a cage con- 
taining 40 females. The object was to see if they would be 
attracted to the females in preference to the rays of light at 
dawn, despite the fact that the air was motionless, 
Heavy rain and wind prevailed during the night, and at 5 
a. m. when I went to the room I found a cool, gray dawn, with 
less light than usual at that hour, but at the lighted window 
were 48 males; only 5 remained unmoved. All of these had 
passed by the cage of females, but not one had paused in his 
response to the lure of the soft light of dawn. But furthermore, 
I had placed at the window 10 females without a cage, but 
despite the fact that there were here five males to each female 
and in close proximity, there was not a single case of mating 
among them. 
I left them there and could pay no attention to them until 
evening. The sun shone intermittently during the day, and at 
times they were in the hot June sun, but none retreated to 
more comfortable quarters. During the evening, I watched them 
at short intervals to see at what hour their activity would begin. 
Until 8:30, all were quiet, but at 9 o’elock I found about half of 
the males fluttering wildly against the pane, as if they were 
trying to reach the moon, which was by this time shining in 
front of them. It seems that this action was actually influenced 
by the bright moonlight, for only ten minutes later when the 
moon was suddenly hidden by a cloud, all but two of the moths 
as suddenly ceased their activity. All this time the two cages 
of females, one with 50 that were four days old and the other 
with 40 moths 114 days old, were in the room, about ten feet 
away, but not one male showed the least indication of leaving 
the lighted window to pay them the slightest heed. This eter 
tling condition cannot be without significance in determining the 
Senses of these creatures, Lutz,* in referring to the case of 
Moths where the males are supposed to locate the females by 
odor, says: ‘‘that none of the experiments believed to have 
demonstrated that odor is the guiding factor in the case of moths 
have absolutely ruled out sound, and male moths have antennas 
quite as plumose, apparently as well fitted to receive sounds, 
as those of male mosquitoes.’ This statement, of course, pre- 
~ “nsect Sounds, Am. Mus. Nat. Hist. 50:337. 1924. 
