470 INSECTA. 



making the pod, they are themselves becoming smaller in proportion to 

 the waste, especially shorter. In a silk-worm which had begun to 

 spin, there was nothing in the stomach or gut ; the whole animal was 

 somewhat shortened, and the gut had two lateral bands running through 

 its whole length, contracting it on the inside, which threw the inter- 

 mediate surface into folds or cells, like the colon in the human subject. 



Of the external changes in the parts, and the motions which bring it 

 from the maggot-state to the chrysalis. — The cuticle or skin of the 

 maggot becomes dry or hard, and of course somewhat transparent ; the 

 rings become rounder and narrower from joint to joint; when the 

 separation is taking place the rings are natter. About the end of 

 twenty-four hours, at the union of the rings, a silky appearance is 

 observed, which is in the direction of the rings, and which is the 

 dried wrinkled skin. There is a considerable motion in the body of 

 the animal, which separates the cuticle from the body, for the body is 

 seen moving within the cuticle. The fore-legs are the last parts 

 that are withdrawn. The dark spots before mentioned [spiracles] 

 become more diffused, or spread ; and at last a darkish line is observed 

 running along the sides of the animal, uniting the dark spots into one 

 line. 



The worm now continues its vermicular motion pretty violently, and 

 a small part on the upper part of the neck opens like a slit, which is 

 continued over the head between the two horny bodies, and divides 

 these into two as far as the mouth. The head now, being separated 

 from its covering all round, slips backward upon the animal, and the 

 animal passes forward through this slit in the neck and back part of 

 the head, so that the covering of the head, the teeth, and face, fall 

 down upon the breast. It now increases its motion and works itself 

 out of the skin, by shoving it backward to the tail, until at last all 

 comes off. In this operation it loses the tail and posterior feet. Before 

 these operations take place, a new cuticle is formed, or perhaps that part 

 which was muscular in the caterpillar-state for the motion of both the 

 body and hind feet, becomes dry and forms itself into a new cuticle, 

 which serves for the covering of the chrysalis. This new skin is at 

 first soft and pale, but in a very little time hardens and becomes 

 brown. 



Of the addition it receives between spinning and the chrysalis. — Within 

 the horny convex plates of the head (which to appearance compose the 

 head) are formed the antennae or horns ; and upon the thigh part of 

 the second and third pairs of the anterior parcel of feet are formed 

 the wings ; and the six legs of the parcel are changed in their form and 

 adapted to their future state. These parts do not exist in the cater- 



