Experiments in Rhythmetic Periodicity 161 
Now the cages were shifted, so the air was blown from the 
males upon the females. Within a few seconds after the ex- 
change of positions, the hitherto active males quieted down in 
the breeze of pure air and remained motionless; the females, 
now placed in the stream of air from the males’ cage, just as 
readily showed response. Within two minutes, four of the 
ten, heretofore stubbornly indifferent, became violently active, 
and in five minutes two more gently responded. The others 
remained unmoved up to the conclusion of the experiment 
ten minutes later. 
This experiment shows clearly that some of the females do 
respond to the odors of the males, and the proportion of these 
compares well with the proportion of females which responded 
when the air was agitated by fanning in the box experiments. 
Exp. 8. June 3. The material was 12 male cecropias which 
had come in that morning at dawn, and 22 from the previous 
Morning. The two cages were placed side by side, with two 
cages of females from one to three days old between them and 
the fan, as in previous eperiments. However, before the females 
were placed there, the stream of pure air was permitted to 
Play upon the two cages of males for an hour. During all 
this time there was not a quiver of response, although at seiaeig 
the strong breeze deflected the wings. Almost immediately 
after the two cages of females were placed between the males 
and the fan, there was very active response among the 22 males 
which had come in the day before; this activity soon developed 
into a very excited flapping and fluttering, and was partici- 
pated in by almost all of this group; this riotous excitement 
lasted for fifteen minutes. The 12 moths in the other a 
which had come in at dawn that morning, were strangly differ- 
ent; despite the fact that they shared equally the wind as it 
came from the cages of the females, and despite the fact ae 
their cage touched that of their neighbors where they could 
undoubtedly hear, see and smell the activity, there was abso- 
lutely no reaction on the part of even one ma e. I si at a 
loss to explain this exceedingly strange behavior; if at sind 
not for the fact that other males responded to such stimuli in 
experiments conducted during their first day in the laboratory, 
One would conclude that the fatigue of the flight that morning 
had made them numb to sounds, odors, etc, whereas those 
