HESPEULDl; EPAllGYllEUS TITVRUS. 1409 



The process by which these parts are pressed flat, aud made to adhere to the body. 

 Is connected, uo doubt, with the act by which] the pupa escapes through the narrow 

 slit on the back of the skin of its larva; but when the larva skin is gently removed, 

 aud the pressure prevented, these parts will all remain free, and dry up in au irregular 

 connection, aud shrivel in au irregular fusion. Or if, immediately after the removal 

 of the larva skin, the young animal be placed in water with a few drops of alcohol, 

 the parts will remain expanded, aud may afterwards be preserved in that condition in 

 a stronger liquid. So that we m.ay derive imperfect butterflies directly from larvae, 

 suiliciently similar to the butterfly which escapes from the pupa to be readily recog- 

 nized, and presenting all the characters of the perfect butterfly, except the imperfect 

 articulations of the legs aud autenuae. the unconnected maxillae, aud the vesicular 

 ■wings. . . . 



When the metamorphosis of the larva is allowed to go on undisturbed, this immature 

 butterfly, with a comparatively loug abdomen, still further contracts. The abdomen 

 especially is considerably shortened and thickened, though its joints remain movable. 

 But the head and thorax and all their appendages are soldered together, and form 

 a solid, immovable case ; aud the connection of the external appendages becomes so 

 intimate, that, instead of appearing like independent parts, they assume rather the 

 appearance of outlines of those organs carved upon a surface, as if they were 

 mere iudications of the parts to be developed in these regions, but seeming to be as yet 

 unformed. Nevertheless, as I have shown above, they were all independent shortly 

 before, aud have become gradually more aud more united in the perfect pupa. (Class, 

 ins. embryol. data, 11-13.) 



Life history. This butterfly is single brooded in the north, double 

 brooded in the south, and in both fegions hibernates as a chrysalis. In 

 the south the butterflies first appear in the latter part of March and con- 

 tinue to emerge from the wintering chrysalids for at least a month, and to 

 fly for certainly a month longer ; the members of the second brood are conse- 

 quently emerging from chrysalids from the middle of June probably until 

 the middle of August, and they continue on the wing until at least the 

 end of September. In the north the butterflies usually make their appear- 

 ance during the first week in June, but not unfi-equently as early as the 2 2d 

 or 24th of May, even toward the northern limits of its range ; indeed the 

 earliest record in the northern states is the earliest above mentioned, at 

 Milford, N. H. (IVliitney) ; they usually become abundant by the middle 

 of June and continue to emerge from the chrysalis untU the very end of the 

 month, although by this time they ordinarily become uncommon in the 

 southern parts of New England ; they continue, however, to fly until the 

 end of July or the first week of August. The eggs, wliich are deposited 

 singly, are first laid about the middle of Jime, sometimes by the end of 

 the first week, and the females arc still ovipositing at the middle of July 

 and undoubtedly until August ; they hatch, according to French, in about 

 four days ; the caterpillars may be found fully grown between the middle 

 of July and the end of September when the last have gone into winter 

 quarters and changed to chiysalis. Mr. Angus writes of a chrysalis which 

 disclosed the imago while in his hand, about the middle of August ; this 

 individual was unquestionably from caterpillars of the same year, and 

 may, perhaps, be considered as an accidental phenomenon ; yet possibly it 



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