208 Trans. Acad. Sct. of St. Louis 
species of Saturniids in one locality have different periods of 
flight helps, of course, to keep the species from interbreeding. 
10. The seat of odor perception is probably located in the 
antennae. Complete removal of these appendages renders the 
male incapable of finding the female. The part of the an- 
tenna containing this sense organ is undoubtedly the basal re- 
gion, since removal of only a portion of each antenna does not 
impede the action of the male, and neither does blinding the 
eyes of the males adversely affect it. 
11. Light rays of certain intensities exert greater influence 
in first arousing the males of all four species than do females, 
for they will often ignore a nearby female to fly to a stream of 
light coming in at a distant window. While the heavily ova- 
laden females are supposed to be more or less sessile, they too 
attempt, in a goodly portion of cases, to struggle (they are too 
heavy to fly) to the light. 
Throughout these pages the reader is often reminded of the 
erudity of the technique, of the improvised apparatus, and 
the limitations encountered in turning one’s home into a Sa- 
turniid laboratory. By this time the thought doubtless enters 
the mind of the reader that experimental work on light reac- 
tions, odor responses and wind velocity should have the benefit 
of a well appointed laboratory. The writer had not gotten far 
into the experiments before he keenly felt the need of such ap- 
paratus, But making the most of any material at hand, he suc- 
ceeded without refined machinery in clearing up several puzzling 
problems in the lives of these mysterious creatures. 
However, the last word has not been said on sex attraction 
and rhythmic periodicity in these moths. Some of the problems 
can be solved with crude, improvised apparatus, and others re- 
quire the use of the highly technical apparatus of a psycholog- 
ical laboratory. From time to time during the course of the 
work, I jotted down these unsolved problems, and I record them 
here in the hope that some one with adequate facilities will un- 
dertake their solution. 
Long distant experiments, five- or ten-mile flights, with 4 
careful study of wind direction and velocity, and a study of the 
relation of wind velocity to speed of flight. 
Horizontal flight vs. vertical flight. In these tests all the 
work was done on a horizontal plane. In a vertical test flight 
