6 THE CANADIAN ENTOMOLOGIST. 



directly near. The altitude of Coalburgh is 600 feet. As appears, the 

 changing of the larvae from New York to Virginia, about 40*^ latitude, 

 besides the difference of altitude, and the reverse, from Virginia to New 

 York, had no perceptible influence on the resulting butterflies of the 

 several broods, except in case of the last one, where the effect of the 

 change of climate was direct on part of them, both as to the form and the 

 size. The periods of the Catskill brood of June may have been 

 accelerated a trifle by transferance to Virginia, but not more, for the 

 weather in the mountains at that time was warm ; and the butterflies 

 retained their peculiarities of color, which, as I have stated, were very 

 marked. So also they retained their habit of lethargy, which, I may say 

 in passing, is a very serviceable habit in a two-brooded species of butter- 

 fly, in a mountain region, and exposed to sharp changes of temperature. 

 If the fate of the species depended on the last larval brood of the year^ 

 and especially if the larvae must reach a certain stage of growth before 

 they were fitted to enter upon their hybernation, it might well happen that 

 now and then an early frost, or a tempestuous season, would destroy all the 

 larvae of the district. The species in the Catskills, in such circum- 

 stances, would probably be about as scarce as it now is on Anticosti. 



On the other hand, the May brood, taken from Virginia to the 

 Catskills, suft^'ered no retardation of their periods, as compared with other 

 larvae of the same generation left at home, nor was there any change of 

 color, nor did any larva become lethargic. It might have been expected 

 that all of the last brood taken to the mountains would have become 

 lethargic, under the severe conditions to which they were exposed, but the 

 greater number resisted change even in this habit. From all which we 

 may conclude that it takes time to naturalize a stranger, and that habits 

 and tendencies, even in a butterfly, are not to be changed suddenly. 



The larvae of tharos are at no period protected by a web, either one 

 common to the community, as with phaeton, or one for each 

 individual, after the habit of jnylitta, according to Mr. Henry Ed- 

 wards, in lit. They are exposed, just as are the larvae of nydeis, and 

 the only shelter either of these species have is what the leaf over them 

 affords. I have left larvae of tharos on the growing food-plant, uncovered 

 by any net, till after first moult, expressly to test the point of a web, as it 

 had been suggested that these larvae might wholly change their natural 

 habit in confinement, something that, so far as I know, larvae never do. 

 The larvae of nycteis I have seen naturally on their food-plant until after 



