100 Trans. Acad, Sci. of St. Louis 
attraction. The females were in the west windows, and the wind 
from the northeast was blowing in at the east windows, so the 
wind passed over the males first and touched the females later. 
After an hour the males were found fluttering, and when the 
lights were turned on, they fluttered violently about the lamps, 
but they did not approach the cages; they wandered out of the 
windows instead. Of course the males’ agitation cannot be at- 
tributed to the presence of the females, because at this hour, 
3:30 a, m., they always become active. After watching them for 
some time I was convinced that they registered no reaction to 
the females near by in this position, and when they wandered 
away I did likewise. On the morning of the following day I 
found 10 of these marked moths clinging to the eages of these 
females. I have no record of the wind throughout the night, and 
do not know whether their eventual success was due to shifting 
breezes, their aimless wanderings, or some other cause. 
Exp. 23. May 23. In Exp. 20, I describe the dearth of 
females, and the marvel that so many males should react to a 
few aged specimens and a single young one. Even these were 
now a day nearer the grave, and not a new one had appeared 
to replenish the stock. The cages were watched from 8 to 4:30 
a. m., but not a native male came to them. During the entire 
period, only 3 came in, and these were marked ones, which have 
been recorded in a previous experiment. Was this due to the 
fact that these females had become so impoverished as to be 
impotent to exercise their attraction, or can it be that the un- 
usual influx of native males at the previous dawn had included 
about all the stray males in the region? I can hardly imagine 
the latter to be true, since I saw the moths coming in from only 
one quarter of the compass. The three which did come 1 
had made successful flights previously, but again one cannot 
tell whether, because of their experience or superior sensitive- 
ness, they could react to weaker female emanations, or whether 
they were aided in their return by something akin to place 
memory. 
Exp. 24. May 23. Wind, east; station, 30 feet west. The 
test on the preceding evening indicated that the males cannot 
find the females, even in close proximity, if the wind is blow- 
ing in the wrong direction. Now we liberated at 8 p. ™. 23 
