All insects, however, do not exemplify “metamorphosis” in so perfect a manner as does the butterfly. The beetles, flies, bees, etc., and many other insects, undergo a process of metamorphosis essentially resembling that of the butterfly; the characteristic feature of this form of development being that while the caterpillar stage is passed in activity, the pupa or chrysalis is quiescent; and from this resting-pupa the active, winged insect comes forth. The dragon-flies, crickets, grasshoppers, and their allies, undergo, on the other hand, a less perfect series of changes than the foregoing insects. The young grasshopper, on leaving the egg, bears first a close resemblance to the perfect insect. It is, further, not of worm-like conformation, and in these two points differs from the larva of the other forms. Then, thirdly, it does not inclose itself in a cocoon-case, but passes its chrysalis stage in a free and active condition. In this respect it again differs from the butterfly chrysalis; and its perfect form is attained simply by the development of the wings. So that, in reality, the chief difference between the young and the perfect form of the grasshopper consists in the non-development in the former of the wings, which are thus characteristic of the adult form. The dragon-flies illustrate an essentially similar kind of metamorphosis, but also exemplify differences in the details of their development. The young of the dragon-fly are active creatures, inhabiting the water of pools; the eggs from which they are produced having been deposited by the parent in bunches on the leaves of water-plants. The larvæ are of brownish color, and possess six legs, and a peculiar apparatus of jaws, consisting of a pair of nippers attached to a movable, rod-like stem. This apparatus can be folded upon the head, when it gives to the larva the appearance of being masked, and hence the name of “mask” which has been applied to this structure. But on the approach of some unwary insect, the jaws can be rapidly extended to seize the unfortunate victim, and convey it to the mouth of its captor. The dragon-fly’s young are thus purely aquatic in habits, and propel themselves along by ejecting water, which has been used in breathing, from the posterior extremity of the body. Having arrived at the close of its chrysalis-stage of development--the chrysalis differing from the larva simply in its greater size, and in the development of the wings and perfect body within the pupa-skin--the insect at length fixes its body to some water-plant. The pupa-skin next splits along the back, and the mature, winged insect slowly emerges therefrom. The crumpled wings soon dry, and acquire their normal consistence; and the dragon-fly, freed from the trammels of a mundane existence, mounts into the air, and “revels in the freedom of luxury and light.” Tennyson has aptly described this change in his lines: To-day I saw the dragon-fly Come from the wells where he did lie.