300 INSECTS INJURIOUS TO VEGETATION. 



antenna, very slender where it joined the head, and broader to- 

 wards the end, hke 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 number, 

 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 cater- 

 pillar prepares for transformation by fastening 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 vi^hich 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 chrysa- 

 lids of other winged moths. The chrysalis tapers very little, and 

 does not end vv'ith a point, but is blunt behind ; and on the edge 

 of each of the rings of the back, there is a transverse row of little 

 pointed teeth which shut into corresponding notches in the ring 

 immediately behind them. These teeth are evidently designed 

 to enable the chrysalis to move towards the mouth of its case, and 

 to hold with, when it is engaged in forcing off the lid in order to 



