SEXUAL SELECTION EXPERIMENTS IN THE 

 CECROPIA MOTH.* 



Phil Rau. 

 Introduction. 



This paper gives an account of an experimental search 

 for the factors at work in determining the choice of mates 

 in Samia cecropia Linn. 



While there has been much contention in the field of 

 Sexual Selection, it has been based too largely upon 

 theory. The present paper is not an attempt to prove 

 or disprove any theory extant, but merely to pick up 

 the simple facts which living material offers us. 



The seventy-three experiments were divided among 

 several problems as follows: 



Given the opportunity of choice : 



1. Do the males mate with the younger or older fe- 

 males? 



2. Do the females mate with the younger or older 



males? 



3. Do the males mate with the beautiful or the unat- 

 tractive and dilapidated females? 



4. Do the females mate with the beautiful or the unat- 

 tractive and dilapidated males? 



5. Do the females mate with the wingless or normal 

 males ? 



6. Is the female capable of mating when both antennae 

 are removed? 



7. Is the male capable of mating when: 



(a) one-half of each antenna is removed; 



(b) all of either antenna is removed; 



(c) both antennae are removed? 



*Read before the Entomological Section, April 27, 1911, and pre- 

 sented by title to The Academy of Science of St. Louis, April 3, 1911. 



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