METAMORPHOSES. 33 



would have continued to reside there until its full growth had been at- 

 tained. Then it would have gnawed itself an opening, and, having entered 

 the earth, and passed a few months in a state of inaction, would at length 

 have emerged an elegant beetle furnished with a slender and very long 

 ebony beak : two wings, and two wing cases, ornamented with yellow 

 bands ; six feet ; and in every respect unlike the worm from which it 

 proceeded. 



That bee but it is needless to multiply instances, a sufficient 



number has been adduced to show that the apparentl} 7 extravagant suppo- 

 sition with which I set out may be paralleled in the insect world ; and that 

 the metamorphoses of its inhabitants are scarcely less astonishing than 

 would be the transformation of a serpent into an eagle. 



These changes I do not purpose explaining minutely in this place : they 

 will be adverted to more fully in subsequent letters. Here I mean merely 

 to give you such a general view of the subject as shall impress you with 

 its claims to attention, and such an explanation of the states through 

 which insects pass, and of the different terms made use of to designate 

 them in each, as shall enable you to comprehend the frequent allusions 

 which must be made to them in our future correspondence. 



The states through which insects pass are four: the egg; the larva; 

 the pupa; and the imago. 



The first of these need not be here adverted to. In the second, or im- 

 mediately after the exclusion from the egg, they are soft, without wings, 

 and in shape usually somewhat like worms. This Linne called the larva 

 state, and an insect when in it a larva, adopting a Latin word signifying a 

 mask, because he considered the real insect while under this form to be as 

 it were masked. In the English language we have no common term that 

 applies to the second state of all insects, though we have several for that 

 of different tribes. Thus we call the coloured and often hairy larvae of 

 butterflies and moths caterpillars; the white and more compact larva? of 

 flies, many beetles, &c., grubs or maggots 1 ; and the depressed larvas of 

 many other insects worms. The two former terms I shall sometimes use 

 in a similar sense, rejecting the last, which ought to be confined to true 

 vermes; but I shall more commonly adopt Linne's term, and call insects 

 in their second state, larvce. 



In this period of their life, during which they eat voraciously and cast 

 their skin several times, insects live a shorter or longer period, some only 

 a few days or weeks, others several months or years. They then cease 

 eating ; ' fix themselves in a secure place ; their skin separates once more 

 and discloses an oblong body, and they have now attained the third state 

 of their existence. 



From the swathed appearance of most insects in this state, in which 

 they do not badly resemble in miniature a child trussed up like a mummy 

 in swaddling clothes, according to the barbarous fashion once prevalent 



1 Gentils, or gentles, is a synonymous word employed by our old authors, but is 

 now obsolete, except with anglers. Thus Tusser, in a passage pointed out to me by 

 Sir Joseph Banks : 



" Rewerd not thy sheep when ye take off his cote 

 With twitches and patches as brode as a grote; 

 Let not such ungentlenesse happen to thine, 

 Least fly with her gentils do make it to pine." 

 D 



