AXTMAL METAMORPHOSIS. 179 



All insects, however, do not sliow such complete transforma- 

 tions as those we have been considering. In some the young 

 maintain a constantly active condition in every stage. In others, 

 as the Orthoptera (which includes locusts, crickets, grasshoppers, 

 and earwigs) and the Hemiptera (bugs and plant-lice), the larval 

 state is passed while in the egg, and the young is hatched in the 

 exact likeness and with the habits of the parent, with perfectly- 

 developed eyes, antennae, jointed legs, and maxillary organs ; the 

 only difference, except size, being that the wings and their cases 

 do not burst through the thoracic rings until after a second moult. 



The larval stage is frequently aquatic. Thus, the beautiful 

 dragon-fly passes its early life as an ignoble water-grub, living in a 

 stagnant pond, soiled with mud and fiUh, gliding steaUhily along 

 the bottom, and greedily seizing worms, water-slugs, and even 

 small fishes, for its prey. The May-flies, caddis-worms, and gnats 

 also spend the earlier part of their existence in the water. 



Many larvae, again, pass their early stage buried in the soil, 

 while others, as stag-beetles, goat-moths, etc., burrow in the wood 

 of trees, or in the bodies of other caterpillars or beetles, as the 

 young of the ichneumon flies, which live as parasites during their 

 sluggish infancy, feeding on the fatty portion of the caterpillar, in 

 which the eggs have been deposited by their careful parent ; while 

 the gad-fly begins its life inside a horse, the judicious mother 

 having placed her eggs on some part of the horse's body which he 

 is sure to lick, and so carry the young grub to its natural warm 

 home ; and the larva of the RJiipidius lives in the abdomen of 

 the cockroach. 



So great is the resistance of the pupal stage to vicissitudes of 

 temperature, that in it insects have been known to be frozen into 

 a solid mass of ice, and still retain their vitality ; and in addition, 

 many, before passing into the crysalis state, envelope themselves 

 in a mantle of silk, which still further protects them from the 

 assaults of wind and rain, while some, as the caddis-worms, pro- 

 tect their larval state by building round themselves a dwelling 

 formed of pieces of grass or rushes, or multitudes of minute 

 shells, or grains of sand agglutinated together by a silken 

 thread ; making use, in fact, of any materials that may be 

 supplied to them : fragments of broken glass of various colours, 



