METAMORPHOSES OF INSECTS. 105 



the common Glow-worm has already afforded us an example of 

 this (Fig. 428). Nearly all Insects lay eggs ; some of them are, 

 however, viviparous. At the extremity of the abdomen of the 

 female, there is often a dart, a saw, or some other organ, fitted 

 to make holes for the reception of the eggs ( 667) ; and by an 

 admirable instinct, the mother always lays them in a place, where 

 her young will find near them the food which they will require ; 

 and yet, in the greater number of cases, this food is not the 

 same as she would seek for herself. During the early period of 

 their lives, insects change their skin several times, and nearly 

 always display some very singular phenomena, of which we have 

 already seen an example amongst the Batrachian Reptiles. The 

 greater number of them, at the time of their coming forth from 

 the egg, neither resemble their parents, nor have the form which 

 they will themselves acquire at a later period ; and before arriv- 

 ing at a perfect state, they undergo changes so considerable, 

 that we cannot better designate them than under the name of 

 metamorphoses. 



681. Insects, in general, pass through three very distinct 

 states, known under the names of the larva state, the pupa or 

 chrysalis state, and the imago or perfect state ; but the changes 

 which take place are not always equally great ; sometimes these 

 ch nges render the animal perfectly different, at other times 

 they only consist in the development of wings ; and these vari- 

 ous degrees of transformation are known under the names of 

 complete, and of incomplete, metamorphosis. 



682. The insects which undergo a complete metamorphosis, 

 are always more or less vermiform (or worm -like), when they 

 come from the egg, and when they are in a larva state ; their 

 body is long, almost entirely soft, and divided into moveable 

 rings, of which the regular number is thirteen. Sometimes they 

 are completely destitute of feet ; at other times they are pro- 

 vided with a variable number of these organs ; but the conform- 

 ation of these is not at all analogous to that of the same parts 

 in the adult animal. They have, nearly always, simple eyes, 

 but they are sometimes entirely destitute of them ; their mouth 



