Rau — Copulation, Oviposition in Samia Cecropia Linn. 311 



To summarize then, only seven pairs remated with 

 their original mates, four males mated with more than 

 one female, and only one female mated with more than 

 one male. 



From so large a series of experiments, and from the 

 fact that in only a few instances and under exceptional 

 conditions mating occurred more than once, I think we 

 must conclude that the species is monogamous. In this 

 decision we need not be disconcerted by the small per- 

 centage of cases of remating, when we consider the un- 

 natural conditions under which the experiments must 

 necessarily be carried on. In nature, where the male 

 must expend in finding the female much vital energy, 

 which is not replenished by taking food or drink, mating 

 may occur but once. In 1909 I was led to observe 

 whether the males were polygamous or monogamous by 

 observing that the males were greatly in excess of the 

 females. At first it was thought that many males were 

 required to fertilize one female, but it was later observed 

 that the insects were not polygamous. In the work of 

 this year the sexes appeared in about equal numbers: 

 101 males to 104 females. 



The aforementioned author was led to observe that 

 the males were polygamous from the fact that in ^*most 

 of the collection of Cecropia cocoons * * * the 

 female pupae outnumbered the males by five to one, 

 and twice by three to one.'' ''For this reason," the 

 author says, ''I inferred that the males were polyg- 

 amous." While it is shown that eleven males mated 

 two females each, it is not shown how many insects, if 

 any, refused to reraate. 



In my previous work I suggested that at one time 

 the species may have been polygamous. May it not be 

 possible that those few exceptional individuals which 

 mated often may have exhibited this primitive trait? 



