Appendix. 145 



larvae from the first generation hibernate, and appa- 

 rently all those from the second. 



Discussion of Results. There are four generations of 

 this butterfly at Coalburgh, the first being Marcia and 

 the second and third Tharos. None of the larvae from 

 these were found to hibernate. The fourth generation 

 under the exceptional conditions above recorded (Exp. 

 4) produced some Tharos and more Marcia the same 

 season, a large proportion of the larvae also hibernating. 

 Had the larvae of this brood been kept at Coalburgh, 

 where the temperature remained high for several weeks 

 after they had left the egg, the resulting butterflies 

 would have been all Tharos^ and the larvae from their 

 eggs would have hibernated. 



The altitude of the Catskills, where Mr. Edwards was, 

 is from 1650 to 2000 feet above high water, and the al- 

 titude of Coalburgh is 600 feet. The transference of the 

 larvae from the Catskills to Virginia (about 48 lat.) and 

 vice-versa^ besides the difference of altitude, had no per- 

 ceptible influence on the butterflies of the several broods 

 except the last one, in which the climatic change exerted 

 a direct influence on part of them both as to form and 

 size. The stages of the June Catskill brood may have 

 been accelerated to a small extent by transference to 

 Virginia, but the butterflies reserved their peculiarities 

 of colour. (See Exp. 5.) So also was the habit of 

 lethargy retained. 5 The May brood, on the other hand, 



5 Mr. Edwards remarks that the habit of becoming lethargic 

 is of great service to a digoneutic species in a mountain region 

 where it is 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 hiberna- 

 tion, it might well happen that now and then an early frost or 

 a tempestuous season would destroy all the larvae of the 

 district." 



