COO a eo a VON RNY ON Neen rr RINE 
SS ed Navan ane ne Rea ee bi aes 
THE CURIOUS HISTORY OF A BUTTERFLY. 515 
but to them is this boon denied ; the cold autumnal blasts sweep 
them away before the eggs are half developed in their ovaries. It 
is, in fact, a vain effort of Nature to develop a second brood which, 
in a more southern climate, with a longer season, would prove 
successful. 
But we have said that this was the history of some only; and 
this fact proves the salvation of the vernal series; when about 
half grown, in the middle of August, while the weather is still 
2 hot, a portion of the caterpillars suddenly cease to eat and fall 
3 into a state of lethargy. Something similar to this, if we may 
trust the observations of Vandouer, as related by Doubleday, has 
been noticed in a European species of this genus, but earlier in 
the season, when it would seem to be more unaccountable, because, 
so far as we can see, less necessary. ‘Having succeeded,” says 
W. Doubleday, “in obtaining some eggs of this species (B. 
Euphrosyne), which were laid about the middle of May, I fed 
the young larve produced from them until'the end of June, when 
they all fell into a state of complete torpidity, in which most of 
them remained until the following spring. But in August a por- 
tion of them woke from. their sleep, fed with voracity, changed 
their skins twice, became pupz and in a few days perfect insects. 
Tt was only at the end of the following February that the others 
commenced feeding, changed their skins twice and after the first 
week in April became pup, from which the perfect insects 
appeared at the usual time.” By this account, the butterflies lay 
their eggs on their first appearance ; either they differ in toto from 
their congeners in America or there is some error in this statement. 
The state of lethargy into which our August caterpillars sometimes 
fall may perhaps be better denominated premature hibernation, 
for they do not arouse themselves until the following spring, when 
hey again resume the cycle of changes peculiar to the vernal 
_ Series, and by this extraordinary habit preserve its history. 
_ Here we have two independent series in the same species, each 
Single-brooded, but one making an effort toward a second genera- ` 
“oy invariably ending in disaster; the butterfly may therefore 
be Properly considered as “ single-brooded,” although differing 
tig from other single-brooded butterflies, by presenting three 
oe distinct apparitions of the perfect form. Whether, by any lethar- 
Bic freaks, the caterpillars of the two series even unite their faces 
nd finally have a synchronous and parallel development, we are 
