The Zoologist— Junk, 1808. 1229 



worm aats its way through the shell of the egg; sometimes the young 

 larva comes out of the egg tail foremost, as the hole in the shell is large 

 enough to allow of the exit of the tail, but is not large -enough for the 

 head to pass through, so the worm is condemned to die in the egg. 

 As soon as it is fairly hatched out the larva continues for some time 

 eating the egg-shell, and then crawls upon a leaf, going to the end of 

 it, where it rests for two or three hours, after which it begins to eat. 

 The hatching out tal<es place early in the morning, from five till ten 

 o'clock; rarely after that lime. 



The Polyphemus worm, like all other silk-worms, changes its skin 

 five times during its larval life. The moulting takes place at regular 

 periods, which come round about every ten days for the first four 

 moultings, while about twenty da\s elapse between the fourth and 

 fifth moulting. The worm ceases to eat for a day before moulting, 

 and spins some silk on the vein of the under surface of a leaf; it then 

 secures the hooks of its hind legs in the texture it has thus spun, and 

 there remains motionless; soon after, through the transparency of the 

 skin of the neck, can be seen a second head, larger than the first, 

 belonging to the larva withiu. The moulting generally takes place 

 after four o'clock in the afternoon ; a little before this time the worm 

 holds its body erect, grasping the leaf with the tw.o pairs of hind legs 

 only ; the skin is wrinkled and detached from the body by a fluid 

 which circulates between it and the worm ; two longitudinal white 

 bands are seen on each side, produced by a portion of the lining of 

 the spiracles, which at this moment have been partly detached; mean- 

 while the contractions of the worm are very energetic, and by it the 

 skin is pulled ofl' and pushed towards the posterior part; the skin 

 thus becomes so extended that it soon tears, first under the neck, and 

 then from the head. When this is accomplished the most difficult 

 operation is over, and now the process of moulting goes on very 

 rapidly. By repeated contractions the skin is folded towards the tail, 

 like a glove when taken off, and the. lining of the spiracles comes out 

 in long white filaments. When about one half of the body appears, 

 the shell still remains like a cap, enclosing the jaws ; then the worm, as 

 if reminded of this loose skull-cap, removes it by rubbing it on a leaf; 

 this done, the worm finally crawls out of its skin, which is attached to 

 the fastening made for the purpose. Once out of its old skin the 

 worm makes a careful review of the operation, with its head feeling the 

 aperture of every spiracle, as well as the tail, probably for the purpose 

 of removing any broken fragment of skiu which might have remained 



