96 THE CANADIAN ENTOMOLOGIST. 



of other species, her attractive pow-^r, as showi 1 think by the experi- 

 ments quoted, affecting the males of her own species only. Therefore I 

 cannot see how the scarcity of any specks of Atticii would be the means 

 of producing hybrids ; surely the absence of the males of one species 

 would not increase the attractive powers of the female to such an extent 

 as to affect the males of another species ; if so, why did not the female 

 promethea exposed by Mr. Bethune attract some of the male cecropias that 

 came so freely to their own female. 



There is another point to be considered in this comparison of birds 

 and moths. During the breeding season a pack of Grouse consists of one 

 male and several females, therefore if half of the pack were killed by 

 hunting, the male would in all probability be amongst them. But in the 

 moths the sexes are, I believe, nearly equal, and even if a species was 

 extensively damaged by parasites, we have no reason for thinking that 

 both sexes would not be represented by the few that escaped the attacks 

 of their enemies, in which case there would be no need of their recurring 

 to another species. 



Dr. Hagen says that in the year that Columbia was taken in Maine, the 

 Atticii were extensively attacked by parasites in that neighborhood. In 

 this locality (Montreal) in 1874, the year that Mr. Pearson found 

 Columbia, the Atticii were remarkably free from parasites ; I do not think 

 there was more than one in eight affected. Mr. Pearson found five 

 cocoons of promethea (it is always rare here), four of which produced the 

 moth ; the other was dead in the chrysalis, but had not been attacked by 

 parasites. Mr. Pearson also found twelve cocoons of cecropia on one 

 tree, all of which produced the moth, and from a large number of cocoons 

 of cecropia and polyphemus, taken in various places around Montreal, the 

 number affected by parasites was comparatively small. 



I suppose the reason that cecropia and promethea are selected as the 

 parents of Columbia is that the dark color of the latter bears a slight 

 resemblance to the smoky color of tl»f male promethea, but how is it that 

 there is no trace of the falcate priim„-ies of that insect in either sex of 

 Columbia, and how is it that in Columbia there is no trace of the very 

 remarkable manner in which the cocoon of promethea is attached to its 

 food plant ? 



Dr. Hagen mentions several instances of hybrids having occurred 

 amongst the Atticii while in confinement. I do not think much import- 

 ance should be attached to this circumstance, as the interbreeding of 



