Mating Instinct in Muths. 189 



the scales were carefully brushed. Male wings were then 

 neatly glued to the stumps, and thus the female presented the 

 appearance of a male. Under these circumstances the males 

 mated with the female quite as readily as they would have 

 done under normal conditions. 



I then tried the experiment of gluing female wings upon 

 the male. Here again the mating seemed to occur with 

 normal frequency, and I was unable to detect that the females 

 displayed any unusual aversion toward their effeminate- 

 looking consorts. 



It is also interesting to note that normal males pay no 

 attention to males with female wings. 



In another series of experiments the wings were cut 

 entirely off of males and females and the scales brushed off 

 of their bodies ; and yet these shabby males were readily 

 accepted by normal females, nor could I see that normal males 

 displayed any aversion to mating with wingless females. 



We are therefore forced to conclude that the melanic colora- 

 tion of the male has not been brought about through the 

 agency of sexual selection on the part of the female. In this 

 connexion it is interesting to notice that Plateau (1897) con- 

 cludes that insects are attracted only by the odours of flowers, 

 and not at all by their colour. 



In conclusion, it gives me great pleasure to express my 

 gratitude to Miss Caroline G. Soule for advice and aid; to 

 W. L. Tower, Esq., for his kindness in collecting many 

 cocoons of the moth ; and to Dr. Robert W. Fuller, who 

 provided me with the reagents used in the manufacture of 

 ethyl mercaptan. 



Summary of Conclusions. 



The male is positively chemotactic toward some substance 

 which emanates from the abdomen of the female, and which 

 he perceives • through olfactory organs situated upon his 

 antennae. 



Females thirty to sixty hours old are much more attractive 

 to males than are young females five to ten hours old. 



Virgin females are somewhat more attractive than are 

 fertilized ones of the same age. 



The male will mate at least four times either with the same 

 or with different females. 



Neither males nor females pay any attention to the appear- 

 ance of their partners. 



The melanic colour of the male has not been brought about 

 by sexual selection on the part of the female. 



