THE LARVA. 41 



Insects present a great diversity of structure; they 

 are sometimes furnished with a distinct horny head, 

 with eyes, antennae, and strong biting jaws, some- 

 times quite destitute of these organs ; and the former 

 are either wholly unprovided with feet, or furnished 

 with six jointed legs upon the three first segments of 

 the body, which are not unfrequently accompanied 

 by a variable number of fleshy clasping organs upon 

 the hinder segments, to which the name of prolegs is 

 commonly given. 



So generally are these preparatory states of Insects 

 known, that our ordinary language possesses names 

 even for the different forms which they present ; thus 

 those which are furnished with a head and feet are 

 called either caterpillars or grubs, apparently according 

 as they feed in the air, or concealed within the sub- 

 stance which furnishes their nourishment ; whilst 

 those in which neither head nor feet are to be ob- 

 served, are commonly known as maggots. Entomo- 

 logists, however, require one common term by which 

 to express the first stage of Insect life, and accord- 

 ingly they denominate all these creatures larvae, from 

 a Latin word signifying a mask, the insect appearing 

 to be, as it were, concealed within a mask during this 

 period of its existence. 



The principal, or indeed the only business of the 

 insect in this stage consists in eating, which it does 

 most voraciously ; and as its bulk increases in propor- 

 tion to this gluttonous consumption of food, its skin, 

 as might be expected, soon becomes too tight for it. 

 This at least is the case with the epidermis, or outer- 

 most layer of the skin, which, however delicate it may 

 be, consists of a substance of the same nature as the 

 hard horny skin of a mature insect, and appears to 



