case by degrees, and then creeps forward, leaving the pupa case behind, still immovably fixed upon the plant. [Illustration: EVENING FLIGHT OF EPHEMERÆ. Page 269.] "Behold," says Réaumur, "the dragon-fly new born, but very different from those which traverse the air, or rest upon the plants around. It is quite in disguise. The body, though longer than the pupa case out of which it was drawn, has not got all its natural length. The wings, which are the large and useful organs of these flies, have as yet very little more volume than they had when enclosed in the short and straitened pupa case. They are merely furrowed plates, or laminæ, of some thickness, and arranged one over the other, as if packed together. One can scarcely conceive how each of these wings can acquire its proper dimensions,--how it is to enlarge and lengthen sufficiently. They are folded into plaits like a fan, or like the leaf of a tree just about to be developed; hence they naturally appear very narrow, and the cause of their appearing so short is, that each of their longitudinal portions is folded up like the paper lanterns, more frequently used by nuns than by other persons." The remaining portion of the dragon-fly's history will be found in the next chapter.[S] Some curious instances are given by various authors of the escape of more than one insect from the same pupa. Thus we are told that a male and female emperor moth were once produced from one larva, and therefore one pupa, of extraordinary size. Messrs. Kirby and Spence tell us of a German entomologist who says, that two specimens of the pine-lappet moth were once produced from one pupa, which was of the remarkable size of two inches in length and one in thickness. But these are very rare instances, the common and almost universal rule being that one pupa only contains one insect. Nothing now remains for us to add to the insect's history in the pupa state. Already,--for it is Spring far advanced,--the air is becoming peopled with insect tribes-- "The insect youth are on the wing, Eager to taste the honied spring, And float amid the liquid noon." A thousand times ten thousand, nay, thousands of thousands, are already in the air; and the low hum of their wings may be heard if we stand breathless and listen in the midst of some sequestered spot, far from the roar and bustle and strife of town life. But the great life-season of the insect world is yet to come; and though May whispers it is nigh, June, July, and August must bring it to us, and with it a teeming multitude of insect flutterers more numerous than the stars of heaven, or the sand-grains of the sea-shore. PART IV.--THE IMAGO. CHAPTER I. THE NEW-BORN PERFECT INSECT.