514 THE CURIOUS HISTORY OF A BUTTERFLY. 
devouring their egg-shells, refuse further food and undoubtedly 
hibernate in this state— which is nearly equivalent to remaini 
in the egg; for eggs of Lepidoptera may be found in midwinter 
in nearly all stages of development, according to the species. 
These juvenile larvæ represent the hiemal condition of one of the — 
two sets of individuals above mentioned; this we will term the ; 
æstival series; for by the end of the following June, the cater — 
pillars have attained their growth and, passing through the chrys- 
alis state, emerge as butterflies about the middle of July ; these 
are the butterflies of midsummer, continuing upon the wing until 
the end of September. In this butterfly, the eggs are wholly 
undeveloped at the birth of the female, and in the æstival series 
are not deposited until September; they hatch in from five to 
nine days and the young caterpillars, as we have said, pass directly 
into a state of hibernation, making the cycle of the year’s changes 
complete with a single generation. This history is quite similar to 
that of the New England species of Argynnis, all of which pi 
single-brooded, appear in early summer, lay their eggs m early 
autumn and hibernate as juvenile larvae ; but these have not super 
added the second series of individuals which form so striking : 
feature in the natural history of some of our native species of 
Brenthis. se. 
This second set of individuals, which we will term the MARE 
in contrast to the estival series, hibernates as half-grown pe 
pillars and produces the earliest brood of butterflies ; these 
their appearance about the middle of May, although yarn 
occasionally seen earlier; they are hardly common before. J w 
of the month and are as long-lived as their companions pe 
æstival series; they do not lay their eggs until the latter p 
series are becoming common ; the eggs hatch and the 
grow as usual for a few weeks, sloughing their integun 
beyond this point all the caterpillars do not develop 
continue in what would appear the natural way ; 
low them — it will be to their grave! As caterpliars s ay 
chrysalides they sleep and then appear in September 
frolicsome butterflies— doomed to an untimely end. - 
of the stival series are busily laying eggs to perpemua’™ 
i ly, one 
* For the phenomenon of midsummer is now repeated inversely; 
iting, the other emerging from the chrysalis. 
