309 



each side being quite narrow. After this the white stripes become much 

 wider and are changed to yellow, and the intervening brownish portions be- 

 come black; so that the full grown caterpillar may be described as yellow, 

 with a dorsal and three lateral black stripes on each side; the head is black, 

 the neck or upper part of the first segment is yellow, as are also the first 

 joints of the legs, of which there are sixteen; the hinderniost pair of fleshy 

 legs are rather long and entirely black, and separated from each other so as 

 to give the tail a forked appearance when elevated. The j^osture of these 

 caterjiUlars, when not eating, is very odd; the body is bent, with both 

 extremities turned upwards, being supported then by the four intermediate 

 pairs of fleshy legs. They have also a singular jerking motion of the head 

 backwards Avhen disturbed, either by being touched, or even by gently shak- 

 ing the branch upon which they happen to be, and then bend themselves 

 still more Into the form of the letter U. These caterpillars appear about the 

 last of July or first of August, and other broods continue to come forth till 

 the 20th or 30th of August, — at least this was the case during the year 1820. 



On the 15th of August, 1822, I found some about two thirds grown. 

 Tliey feed from thirty-five to thirty-seven days or about five weeks. The 

 individuals of each brood keep together upon the branch where they were 

 hatched, devouring in their progress every leaf from the extremity down- 

 wards to the trunk. I have seen branches eight feet in length thus stripped, 

 without satisfying them; after which they attack the branch which happens 

 to be nearest to them. As they move along they carry a silken line with 

 them; and they form under the branch a sort of network' with silk to 

 Avhich they retire for j^i'otectlon during high Avinds and rainy weather. 

 They change their skins twice at least, perhaps a greater number of times. 



These tvv^o moultlngs I observed to take place on the 20th and 26th days 

 of their age ; but I never discovered any other changes of their skins while 

 they remained in the caterpillar state. The largest caterpillar of this kind 

 that I have seen measured one inch and three quarters In length. At the 

 end of five weeks they cease feeding, descend from the trees, enter the earth, 

 and within twenty-four hours afterwards are changed to chrysallds of a 

 brown color. Their descent always takes place during the night, and on 

 the following morning not one of the brood will be seen on the tree. Those 

 which I fed in flower pots half filled with earth became chrysalids in the 

 earth, and remained in the pupa state till the 20th of July of the following 

 year. On the 22d July, 1821, 1 also found two of the millers apparently just 

 disclosed from the pupas on the side of a building In the open air. 



Aug. 2, 1848. Larva found on Andromeda. Black above and beneath, 



* This was added to the original notes at a subsequent time. Does it refer to this in- 

 sect, or to some other nearly like it ? 



