320 INSECTS INJURIOUS TO VEGETATION. 



insect extended and drew in at pleasure, and which, when 

 they were out, were kept in continual motion. On each side 

 of the middle of the head, there was a black and flexible kind 

 of antenna, very slender where it joined the head, and broader 

 towards the end, like the handle of a spoon. The first three 

 pairs of legs were equal in length, and armed with stout horny 

 claws. The other legs, if such they could be called, were ten 

 in nvimber, and so short that only the oval soles of the feet 

 were visible, and these were surrounded by numerous minute 

 hooks. The tail end of the body was as blunt as if it had 

 been cut off with a knife; it sloped a little backwards, and 

 consisted of a circular horny plate, of a dark gray color, which, 

 when the caterpillar retired within its case, exactly shut up one 

 of the holes in it. This caterpillar eat the leaves of the oak, 

 and fed mostly by night; while eating it came half way, or 

 more, out of its cocoon; and in moving laid hold of the leaf 

 with its fore legs, and then shortened its body suddenly, so as 

 to bring its cocoon after it with a jerk; and, in this way, it 

 went by jerks from place to place. When it had done eating, 

 it moored its case to a leaf by a few silken threads fastened to 

 one, and sometimes to both ends; and before moving again, 

 it came out and bit off these threads close to the case. It 

 could turn round easily within its case, and go out of either 

 end, as occasion required. So tenaciously did it cling to the 

 inside of its case with the little hooks of its hinder feet, that 

 all attempts to make it come wholly out, except by a force 

 which would have been fatal to the insect, were without effect. 

 This kind of caterpillar prepares for transformation by fasten- 

 ing both ends of its cocoon to a branch, and then stops up 

 each of the holes in it with a little circular silken lid, exactly 

 fitting the orifice, and made about the thickness of common 

 brown paper. There is no great difference in the size or form 

 of the chrysalids which produce the male and female moths; 

 they are about three quarters of an inch in length ; on both of 

 them the sheaths for the wings, antennae, and legs, are alike, 

 and are as plainly to be seen as on the chrysalids of other 

 winged moths. The chrysalis tapers very little, and does not 

 end with a point, but is blunt behind; and on the edge of 



