286 Trans. Acad. Sci. of St. Louis. 



the male, thereby gently stroking his wings and lateral parts of the 

 abdomen. Once more male 17 knocks the female to the floor, and as 

 she again starts for the top he defiantly takes his position just ahead 

 of her. Her persistence is stubborn, but his hindrance at last stops 

 her progress. After a few seconds male 62 drops beside the female, 

 whereupon male 17 flies up to the top and apparently awaits the 

 female. Male 62 and the female together have climbed part way up 

 and are clinging to the side wires, when male 17 comes down and 

 flutters wildly about the female with great commotion. At last, arter 

 so much exertion, he has won her recognition, and we now see the 

 pair flitting merrily about each other for just a minute and a half. 

 Meanwhile male 62 betakes himself again to the dome, and in a short 

 time after her merry frolic we see the female slowly making her way 

 back to him. As she drav/s nearer and nearer to the jealously coveted 

 place, the fluttering on the part of male 17 becomes more and more 

 violent, until again he succeeds in beating her to the floor; he promptly 

 joins her there and they resume their merry whirls. But the female 

 heeds him for only one-half minute, and then turns back to her first 

 choice. It is now 8:37 P. M. The female comes directly in front of 

 male 62, and closing her wings on either side of him (both hang free) 

 almost hides him from view. In this position she violently flaps her 

 wings, and as they close over the male they strike the lateral portions 

 of his body and the under sides of his wings. He is motionless and 

 unresisting. And now while male 17 quietly remains below, these two 

 playfully wheel about each other in alternating circles. At 8:42 all 

 become quiet, the chosen pair at the top, and male 17 hanging a short 

 distance away. May 2, 8:00 A. M. The female in copulo with male 62. 



Tliroiigliout tlie experiment it was clearly evident that 

 her preference was for the dilapidated male, which was 

 the younger, but it seemed that the eagerness and 

 strength of male 17 might prevent the mating. 



Experiment 12. — May 1, 8:40 P. M. 



(^59. Age day 5:00 hours. 



(^61. Age day 4:50 hours. A beautiful insect; the usual 

 dark rings of pubescence on the abdomen are bright 

 red; one antenna somewhat deformed and right fore- 

 leg missing. 



9 67. Age day 2:35 hours. 



Object. — To see, when both males are of almost the 

 same age, whether a slightly deformed one of abnormally 

 bright color will mate in preference to a perfect insect 

 of only normal color. 



