350 



head to the ends of the closed wings, five sixteenths of an inch. 

 Expansion of the wings five eighths of an inch. 



These worms, or caterpillars, grow to the length of about half 

 an inch. Though varying somewhat in hue, they are mostly of 

 a pale yellowish green color, with two blackish lines along the 

 top of the back, and a brownish head. Under a magnifier, a 

 few short hairs can be seen on the body, arising singly from little 

 black points, arranged in threes on each side of every ring ; and 

 there are usually two, more or less conspicuous, semicircular, 

 blackish spots on the top of the first ring. They have sixteen 

 feet ; the first three pairs being jointed, and ending with a point 

 or claw, the others fleshy tubercles without proper joints. They 

 are very impatient of being touched, and on being taken into the 

 hand, move with great agility, and by jerks, both forwards and 

 backwards. When the trees are shaken, the insects spin down, 

 and hang suspended by threads. Probably most of them leave 

 the trees in the same way, when their course is finished. In 

 some places, it was observed that they all took their departure 

 during heavy showers, towards the end of June. My official 

 engagements, at that time, prevented my observing their progress 

 abroad. 



All the specimens sent to me, that remained alive, together 

 with a few from my trees, were put into a wide-mouthed bottle, 

 and were supplied with leaves. About the 28th of June, some of 

 these worms began to cover themselves with a transparent web, 

 formed of a few delicate silken threads. One of them was trans- 

 formed to a chrysalis within its web on the 5th of July, and be- 

 came a winged moth on the 9th ; having remained in the chrys- 

 alis state only four days. Others were more tardy in their 

 transformations ; and one still remains a chrysalis. More than 

 half of the whole were unable to take this form, having perished 

 in the worm state from the attacks of an internal parasite, a 

 minute grub, which, after preying on the vitals of its victim, left 

 the body, and spun itself a little oval whitish cocoon or pod, from 

 which it emerged soon afterwards as a tiny four-winged ichneu- 

 mon fly. 



The chrysalis of the palmer-worm is only one-quarter of an 

 inch long. It is of a pale brown color, and differs from that of 



