584 THE BUTTERFLIES OF NEW ENGLAND. 



The 22iid May, 1826, I obtaiuecl a quantity of eggs of the species. The uew cater- 

 pillars were like those of 1819. They lived in tlie same way. They all stopped eating 

 toward the end of June and I Avas nearly as much astonished at it as the first time. 

 These larvae remained motionless during the month of July excepting a few Avhich 

 moved about as if searching for something. I supplied them with fresli and tender 

 leaves of which they partook sparingly. 



The 8th August, seven of these caterpillars appearing to me to have recovered tlie 

 size which they had at the beginning of lethargy, I placed them apart in a box and 

 provided them with their ordinary food. A little afterward I Avas sure that their 

 vital functions were in action as before. They grew rather quickly, moulted twice 

 and entered the chrysalis state, becoming butterflies in the course of the same month 

 of August. Nevertheless, the greater number of my euphrosine caterpillars were 

 still in their primitive aestival torpor ; they continued therein until the approach of 

 spring this year, 1827. At the time of the thaw, which commenced the 2Gth February, 

 a dozen endeavored to move languidly l^ut partook of almost no nourishment until 

 the temperature became a little higher. Afterwards they increased in size rather 

 slowly, moulted twice, and finally underwent their metamorphoses between the 7th 

 April and 10th May. But the winter, which was long and severe, although late, killed 

 two-thirds of the caterpillars in my entomological menagerie. 



Tlie 27th July, 1826, a euphrosine $ of the second brood furnished me again with a 

 quantity of eggs. The caterpillars moulted three times and afterwards became torpid 

 like their predecessors ; only none of them revived the same year. They remained in 

 this lethargic state the greater part of the winter. Their resuscitation took place the 

 26th February, 1827, that is, at the same time as tliat of most of the first caterpillars 

 of euphrosine, which had remained concealed in dry leaves since the close of June, 

 1826. In fact these two batches underwent their final metamorphoses together with- 

 out showing any sign leading one to suspect that some were born later than the others. 

 In closing these remarks I will add that this year, 1827, I wished to confirm anew what 

 I have said. I procured new caterpillars of euphrosine which have behaved exactly 

 in the same way as their elders. 



It appears from this very explicit account that euphrosyne at least is 

 double brooded, appearing on the wing in May and again in July-August ; 

 that both broods lay eggs very soon after eclosion ; that the caterpillars of 

 the second generation have attained half their size when Avinter forces 

 them to hibernate, while those of the spring brood, when half-grown (that 

 is, at the hibernating age) fall into a state of lethargy from which most do 

 not recover until spring ; a few, however, resume eating and produce the 

 July butterflies, — the progeny of the two broods thus uniting to form the 

 spring butterflies, when the same process is again repeated. 



Doubleday (Gen. diurn. Lep., i: 172-173), after giving an abstract of 

 the above memoir, oflfers the following comments: "In England we 

 rarely see the perfect insects of either A. selene or euphrosyne in the 

 autumn, but they are more often met with on the continent of Europe. 

 The second appearance of several species of this genus is to be explained 

 by this habit of the larvae, not by their being double brooded. It would 

 be curious to know if the specimens disclosed from the pupae in the 

 autunni have any progeny, and, if so, to learn their history. Probably it 

 will be found that the ovaries of the females are imperfectly developed, 

 and that they consequently never lay any eggs, or that they hibernate and 

 lay their eggs in the spring, as do the Vanessae." 



