Rau — Sexual Selection Experiments in Cecropia Moth. 279 



the slightest movement on the part of the female. The male flutters 

 about, throwing himself bodily against her four or five times, and 

 then quietly waits. — 4:30. All is quiet. The male has no doubt dis- 

 covered that all attempts at attracting the female are futile. — ^April 28, 

 11:00 P. M. Death of the female. Mating has not taken place, although 

 the pair have been together for over three days. 



This shows that an old fertilized female would not 

 mate again, even with a spirited young male. 



How different was the behavior of these females, in 

 experiments 3 and 4, the one coldly indifferent, the other 

 wildly eager, and, strange to say, the older was the more 

 unladylike of the two. 



Experiment 5. — April 28, 11 :55 P. M. 



J' 3. Age 7 days 8:25 hours. Previously mated; wings badly 



damaged. 

 (^ 6. Age 6 days 9:25 hours. 

 (^27. Age days 6:05 hours. 

 5 25. Age days 6:55 hours. 



Object. — To see which male will be given the preference 

 by a normal virgin female, that is, if the female does the 

 choosing; or which of the three males will be victor in 

 the struggle for a mate. 



Behavior. — 11:55. The three males immediately become active as 

 follows: Male 3, which has previously mated and whose wings are 

 in no condition to flutter, wabbles along the floor, frequently falling 

 to one side. Male 6, the oldest unmated male, has fluttered wildly 

 about the female and has been beating against the domed ceiling and 

 the floor alternately for two minutes. The young male 27 has assumed 

 a position on the floor of the cage and gently vibrated the wings for 

 two or three minutes. Male 6, after resting a half minute, flutters 

 with male 27 wildly around the female, where she clings at the top 

 of the cage, slowly moving her wings to and fro. This commotion has 

 lasted about two minutes, during which time the males have often 

 knocked one another as well as the female to the floor. During all 

 this, male 3 has remained on the floor, nervously shaking his remnants 

 of wings and legs. All of the work so far has led to the conclusion 

 that the insects are monogamous. Yet we see that male 3, which is 

 pretty well on in age and has already mated, becomes sexually excited 

 when in the presence of others in that condition. 12:00 Midnight. All 



