t> INSECTS INJURIOUS TO VEGETATION. 



Struggle begins, the chrysalis-skin bursts open, and from the rent 

 issues a butterfly, or a moth, whose small and flabby wings soon 

 extend and harden, and become fitted to bear away the insect in 

 search of the honeyed juice of flowers and other liquids that suf- 

 fice for its nourishment. 



The little fish-like animals that swim about in vessels of stag- 

 nant water, and devour the living atoms that swarm in the same 

 situations, soon come to maturity, cast their skins, and take an- 

 other form, wherein they remain rolled up like a ball, and either 

 float at the surface of the water, for the purpose of breathing 

 through the two tunnel-shaped tubes on the top of their backs, 

 or, if disturbed, suddenly uncurl their bodies, and whirl over and 

 over from one side of the vessel to the other. In the course of 

 a few days these little water-tumblers are ready for another trans- 

 formation ; the skin splits on the back between the breathing- 

 tubes, the head, body, and limbs of a mosquito suddenly burst 

 from the opening, the slender legs rest on the empty skin till the 

 latter fills with water and sinks, when the insect abandons its 

 native element, spreads its tiny wings, and flies away, piping its 

 war-note, and thirsting for the blood which its natural weapons 

 enable it to draw from its unlucky victims. 



The full-fed maggot, that has rioted in filth till its tender skin 

 seems ready to burst with repletion, when the appointed time 

 arrives, leaves the offensive matters it was ordained to assist in 

 removing, and gets into some convenient hole or crevice ; then its 

 body contracts or shortens, and becomes egg-shaped, while the skin 

 hardens, and turns brown and dry, so that, under this form, the 

 creature appears more like a seed than a hving animal ; after some 

 time passed in this inactive and equivocal form, during which 

 wonderful changes have taken place within the seed-like shell, 

 one end of the shell is forced off", and from the inside comes forth 

 a buzzing fly, that drops its former filthy habits with its cast-off 

 dress, and now, with a more refined taste, seeks only to lap the 

 solid viands of our tables, or sip the liquid contents of our cups. 

 Caterpillars, grubs, and maggots undergo a complete transfor- 

 mation in coming to maturity ; but there are other insects, such 

 as crickets, grass-hoppers, bugs, and plant-lice, which, though 

 differing a good deal in the young and adult states, are not subject 

 to so great a change, their transformations being only partial. For 



