TRANSFORMATION OF INSECTS.

5

and take another form, wherein they remain rolled up like ahall, and either float at the surface of the water, for the pur-pose of breathing through the two tunnel-shaped tubes on thetop of their backs, or, if disturbed, suddenly uncurl theirbodies, and whirl over and over from one side of the vesselto the other. In the course of a few days these little water-tumblers are ready for another transformation ; the skin splitson the back between the breathing-tubes, the head, body, andlimbs of a mosquito suddenly burst from the opening, theslender legs rest on the empty skin till the latter fills withwater and sinks, when the insect abandons its native ele-ment, spreads its tiny wings, and flies away, piping its war-note, and thirsting for the blood which its natural weaponsenable it to draw from its unlucky victims.

The full-fed maggot, that has rioted in filth till its tenderskin seems ready to burst with repletion, when the appointedtime arrives, leaves the offensive matters it was ordained toassist in removing, and gets into some convenient hole orcrevice; then its body contracts or shortens, and becomesegg-shaped, while the skin hardens, and turns brown anddry, so that, under this form, the creature appears more likea seed than a living animal; after some time passed in thisinactive and equivocal form, during which wonderful changeshave taken place within the seed-like shell, one end of theshell is forced off, and from the inside comes forth a buzzingfly, that drops its former filthy habits with its cast-off dress,and now, with a more refined taste, seeks only to lap the solidviands of our tables, or sip the liquid contents of our cups.

Caterpillars, grubs, and maggots undergo a complete trans-formation in coming to maturity; but there are other insects,such as crickets, grasshoppers, 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 transformationsbeing only partial. For instance, the young grasshoppercomes from the egg a wingless insect, and consequently un-able to move from place to place in any other way than by