METAMORPHOSES OP INSECTS. 105 



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

 this (Fig. 328). Nearly all Insects lay eggs ; some of them are, 

 however, viviparous. There often exists at the extremity of the 

 abdomen of the female, a dart, a saw, or some other organ, 

 fitted to make holes for the reception of the eggs ; 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 tunes, 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. 



623. Insects, in general, pass through three very distinct states, 

 known under the names of the larva state, the chrysalis state, and 

 the imago or perfect state ; but the changes which take place, are 

 not always equally great ; sometimes these changes render the 

 animal perfectly different, at other times they only consist in the 

 development of wings ; and these various degrees of transforma- 

 tion are known under the names of complete, and of incomplete, 

 metamorphosis. 



624. 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 com- 

 pletely destitute of feet ; at other times they are provided witli 

 a variable number of these organs ; but the conformation 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 is usually fur- 



