25 BRITISH BUTTERFLIES. 



so as fully-formed larvae, but within, and not without, the eggshell. This 

 is the case with Parnassius apollo, P. smintheus, and P. elodius, Argynnis 

 adippe, Bithys quercus, Pairalis betulae, Strymon (Thecla) w- album, 8. 

 pruni, Agriades cor y don, Plebeius aegon, Adopaea lineola, and possibly 

 also Urbicola comma. The young larva of Argynnis elisa, like that of A. 

 adippe, hybernates within the egg, but most remarkable of all are 

 the resting-periods of Argynnis aglaia and Dryas paphia, for, although 

 the larvae of these two species hatch in July or August, when there is 

 an abundance of food and a high temperature, they positively refuse 

 to feed, and, in exactly the same stage as they leave -the egg, pass 

 through the winter, awaiting the first warm days of spring before 

 partaking of their first food, i.e., they rest for fully six months after 

 hatching before making a single move towards food and ultimate 

 growth. Although, as already noted, Argynnis adippe must be said to 

 hybernate as an egg, yet the larva is fully formed in autumn, and it, 

 too, lives on until February, but inside the eggshell, whilst those of 

 A. aglaia and Dryas paphia live outside it. Scudder, evidently without 

 any definite knowledge on the point, notes (op. cit., p. 689) that larvae 

 may rest fully-formed throughout the winter in the unhatched egg, 

 and he thinks that " it is possible that, to the list of butterflies hyber- 

 nating in the larval stage, should be added those " Theclids and 

 Chrysophanids that ostensibly pass the winter in the egg state." 

 " If," he says, " as is probable, these eggs mature during the hot 

 season in which they are laid, and not in the succeeding, cooler, early 

 spring, when the caterpillar escapes, then the only difference between 

 these caterpillars and those of the Argynnids is that one passes the 

 winter within, the other without, the eggshell ; and their refusal to 

 escape in the warm weather points to premature hybernation, begin- 

 ning in a kind of lethargy." Certainly this is the case with regard to 

 our British egg-hybernating species, and one wonders whether both 

 phenomena are not shown in the American, as well as in the European, 

 Argynnids. Of the North American species, stated by Scudder to 

 hybernate as soon as hatched, he notes (op. cit., p. 561) of Argynnis 

 cybele, " the eggs hatch in about fifteen days, but the caterpillars from 

 them go immediately into hybernation without eating anything more 

 than their eggshell ; " of A. aphrodite, he says (p. 568), "it hybernates 

 direct from the egg," and of A.atlantis, " it hybernates as soon as hatched, 

 and before eating" (p. 577). Of Brenthis myrina and B. bellona 

 (op. cit. pp. 599, 616) he says, respectively, "winters sometimes just 

 from the egg, sometimes when half-grown," and " some larvae feed 

 until they have passed two or three moults and then winter, .... 

 while others hybernate at once after leaving the egg." Both these 

 latter statements require careful confirmation. Scudder notes (p. 689) 

 of this peculiarity of larvae hybernati.bg as soon as they leave the egg : 

 " The hybernation of caterpillars just born is a most surprising fact. 

 As they eat nothing, one would think they might at least have had the 

 protection of the eggshell and wintered within the egg, but, in the 

 cases in point, Satyrines and Argynnids, the eggs are naturally laid 



upon the leaves of plants which die down in winter 



Hybernation at this tender age is all the more surprising from the 

 fact, known only too well to everyone who has attempted to raise 

 butterflies from the egg, that the greatest mortality exists among 

 caterpillars in the first stage of existence, whether from natural causes 



