20 THE INSECT WORLD. 



Tlie egg state, which is common to them, as to all other articu- 

 late animals, it is unnecessary to explain. Nearly all insects lay 

 eggs, though some few are viviparous. There often exists in the 

 extremity of the abdomen of the female a peculiar organ, called 

 the ovipositor, which is destined to make holes for the reception 

 of the eggs. By a wonderful instinct the mother always lays her 

 eggs in a place where her young, on being hatched, can find an 

 abundance of nutritious substances. It will not be needless to 

 observe that in most cases, these aliments are quite different to 

 those which the mother seeks for herself 



In the second stage, that is to say, on leaving the egg — the larva 

 period — the insect presents itself in a soft state, without wings, and 

 resembles a worm. In ordinary language, it is nearly always called a 

 worm, or grub, and in certain cases, a caterpillar. 



I.innasus was the first to use the term '' larva "' — taken from the 

 Latin word larva ^ " a mask " — as he considered that, in this form, the 

 insect was as it were masked. During this period of its life the insect 

 eats voraciously, and often changes its skin. At a certain period it 

 ceases to eat, retires to some hidden spot, and, after changing its skin 

 for the last time, enters the third stage of its existence, and becomes a 

 chrysalis. In this state it resembles a mummy enveloped in bandages, 

 or a child in its swaddling clothes. It is generally incapable of either 

 moving or nourishing itself It continues so for days, weeks, months, 

 and sometimes even for years. 



While the insect is thus apparently dead, a slow but certain change 

 is going on in the interior of its body. A marvellous work, though 

 not visible outside, is being eftected, for the different organs of the 

 insect are developing by degrees under the covering which surrounds 

 them. When their formation is complete, the insect disengages itself 

 from the narrow prison in which it was enclosed, and makes its 

 appearance, provided with wings, and capable of propagating its kind 

 in short, of enjoying all the faculties which Nature has accorded to its 

 species. It has thrown off the mask ; the larva and pupa has dis- 

 appeared, and given place to the perfect insect. 



To show the reader the four states through which the insect passes 

 in succession, in Fig. i6 is represented the insect known as the 

 Hydi'Ophilus* firstly, in the egg state ; secondly, as the larva, or 

 caterpillar ; thirdly in the pupa ; and fourthly as the perfect insect or 

 imago. The different degrees of transformation and evolution which 

 we have just described, are those which take place either completely 



■* A kind of water-beetle. — Ed. 



