POLYMORPHIC BUTTERFLY. 265 
by this means to capture it. It is a shy insect and darts out of 
its course at the least motion.” Speaking of the autumn brood, — 
which he considers a distinct species, he adds (loc. cit.): “its 
flight is rather more graceful than that of P. Ajax [i. e. the spring 
brood] ; it sometimes alights in the muddy places by the roadsides 
where little streamlets cross, especially during the heat of the 
irtland, too, remarks: “these two species are readily 
recognized by their peculiar mode of flight ;”* but Edwards makes 
no comment “pon this point. 
“ Many eggs,” says Biwig i “are destroyed by insects and 
spiders. There is a minute scarlet spider scarcely larger than the 
egg itself, that mounts upon it and from a puncture extracts the 
contents. I frequently met the shells so despoiled before I dis- 
covered the cause, and have since observed the marauder in its 
operations. I have also lost in a single night, owing as I sup- 
posed to crickets, numbers of eggs laid in confinement.” Speak- 
ing of the caterpillar he says: “Ihave . . . seen spiders feeding 
upon them, attacking even the head, and they have other enemies 
among the insects! They are very little troubled by ichneumon 
flies in this valley, and I have rarely lost a chrysalis from that 
cause. Consequently no Papilio is so abundant here throughout 
the season. I find on breeding them that a considerable percentage 
of the eggs do not hatch, and that more or less of the larvæ die 
at every moult, as well as in the effort to change to chrysalides. 
Multitudes of chrysalides, must be destroyed in the winter by birds 
and mice as they are but imperfectly concealed under stones and 
roots, or even among the stems of the grasses, so that of the tens 
of thousands of eggs that are annually deposited, but a very 
small proportion produce butterflies.” The caterpillar is, however, 
sometimes attacked by Trogus exesorius Brullé, the imago of which 
escapes from the chrysalis by cutting a circular opening, usually 
through one of the wings. 
Desiderata. Although so carefully studied by Mr. Edwards, there 
are still sorne points in the history of Ajax which require inves- 
tigation. The distribution of the insect in the west and. of each 
form throughout its natural range should be more definitely deter- 
mined. The season of the apparition of the different varieties -in 
the extreme southern states, and of the different broods of Mar- 
cellus everywhere, is still unknown and will require careful study ; - 
* Trans. Entom., Soc. Lond., n. s. i, 1851, Proc. ci. 
