88 INTERNAL ORGANS. 



in cellular tissue, to be used at a fixed epoch of 

 the caterpillar's life, when its continued existence 

 depends upon this reserve force. On opening the 

 body, we find a great quantity of fatty matter, in 

 continuous layers of convoluted lobules, strapped 

 down by the muscles between which it has pene- 

 trated, enwrapping the whole intestinal canal, 

 and filling every space that can be found between 

 the different organs of the body. 



This explains the voracity of the caterpillar, 

 and shows that the main end of its existence is to 

 gormandize and grow ; examining its interior, we 

 find that the muscles occupy hardly more space 

 than twice the thickness of the skin to which they 

 are attached ; and their very object is to move the 

 creature to a feeding spot or remove the old in- 

 tegument to admit of a larger growth and a greater 

 capacity for food ; those of the head are almost 

 exclusively attached to the jaws. The general 

 cavity of the body is mostly occupied by the ali- 

 mentary canal and its appendages, the glands and 

 nerves and even the tracheae really requiring an 

 insignificant amount of space ; and whatever is 

 not occupied by these organs, necessary to the 

 assimilation of food, is choked up with the fatty 

 masses embedded in the cellular tissue. 



