Rau — Sexual Selection Experiments in Cecropia Moth. 287 



Behavior. — 8:40. When placed together male 61 gently moves the 

 wings, male 59 rests quietly while the female moves to male 61 and 

 both hang from the top. Male .59 slowly moves behind the female, and. 

 now all three form a single file, the female in the center. They make 

 a handsome showing all in a row, majestically waving the wings. 

 After a few seconds male 59 in the rear, crowds in front of the 

 female between her and his rival, whereupon the latter drops to the 

 floor. The wings of the female are still moist; this prevents active 

 movements. Male 61 has crept part way up the side of the cage, and 

 all remain quiet. No insect in the cage shows any eagerness to mate. 

 We little wonder at this when we remember that none is over 5 hours 

 old. — May 2, Midnight. They have been watched all day, with no evi- 

 dence of mating. — May 3, 8:00 A. M. Not yet mated. — 8:47. Mating 

 has at last taken place with male 61, the brightly colored insect with 

 crippled antenna and one fore-leg lacking. This one, incidentally, is 

 slightly younger. 



Experiment 13.— May 1, 9 :20 P. M. 



(j'SS. Age days 5:40 hours. Wings removed. 

 c^41. Age 2 days 5:50 hours. 

 9 60. Age days 5:35 hours. 



Object. — In Experiment 6 the difference in the age of 

 the males was too great. In this experiment we shall 

 find whether the female prefers a normal insect, 2 days 

 old, to a mutilated one, 5 hours old. 



Behavior. — 9 : 20. After three-quarters of a minute of absolute quiet, 

 the female and male 58 crawl to the top from opposite directions. At 

 the first attempt he falls, but at once remounts, and as he reaches the 

 top, draws near the female. Her wings now gently but rapidly flutter, 

 sometimes striking the remnants of his wings. Male 41 lies on the 

 floor directly beneath. The female, clinging to the wires with the 

 body in a vertical position, like a boy swinging on a horizontal bar, 

 comes nearer to male 58, and in so doing she turns her body completely 

 about three times, each time bringing her so much nearer to the male.^ 

 He drops to the floor (no doubt accidentally, being mutilated), while 

 the female clings to the cage just above him, spreading her wings to 

 the fullest extent. — 9:26. Male 41 lazily lies at the bottom of the cage; 

 male 58 again attempts to reach the top but stops about half way. At 

 the top the female slowly moves her wings. They are still somewhat 

 moist, and perhaps this movement is really because they are being 

 inflated. Male 58 has resumed his efforts to reach the top where the 

 female rests, and sometimes eagerly moves his stubs of wings; male 41 

 is fluttering on the bottom of the cage. — 9:35. For five minutes male 41 

 has been flapping his wings, occasionally flitting to the top and throw- 

 ing himself violently against the female. She flaps her wings as she 

 clings to the dome, and occasionally flies about. At length all are at 



