520
��rvoi_ v., vo. \&
��L
��and bent tibine are rubbed over the clypeus, the uiimeroua stiff hairs on which act like a comb or a brush in freeing the spine of dirt.
As the time approaclies for the issuing of the pupa, it gradually rises nearer and nearer to the surface ; and, for a jear or two before the appearance of any given brood, the pupa may be dug up within one or two feet of the surface.
In the year of their ascent, from the time the frost leaves tbo ground, they are found close to the surface, and also under logs and stones, seeming to await the op|H)rtune mo* ment, and apparently without feeding. They begin to rise from about the 20th of May in more southern localities, and but little later farthernorth. luWushingtoa, ihe present year, they began to rise in scauty numbers about the 23d, and were perhaps most numerously rising on the night of the 27th. Those in the city were somewhat earlier than those in the woods jiwt over on the Virginia aide. The unanimity with which all those which rise within a certain radius of a given tree crawl in a bee-line to the trunk of that tree, is most iuterestiug. To witness these pupae in such vast nambera that one cannot step on the ground without crush- ing several, swarming out of their subterranean boles and scrambling over the ground, all con- verging to the one central point, and then in a steady stream clambering up the trunk, and diverging again on the branches, is an experi- ence not readily forgotten, and affording good food for speculation on the nature of instinct. The phenomenon is most salisfaclorily wit- nessed where there is a solitory or isolated tree.
The pupae begin to rise as soon as the sun is hidden behind the horizon, and they continue, until, by nine o'clock, the bulk of them have risen. A few stragglers continue until mid- night. They instinctively crawl along the horizontal branches after they have ascended the trunk, and fasten themselves in any posi- tion, but preferably in a horizonlal position on the leaves and twigs. In about an hour after rising and settling, the skin splits down the middle of the thorax from the base of the clypeus to the base of the metanotura, and the forming cicada issues. Ecilysis is always an interesting phenomenon, and, when closely watched in our cicada, cannot fail to entertain.
There are five marked positions or phases in this act of evolving from the pupa-shell ; viz.. the straight or extended, the hanging head downward, the clinj;ing head upwanl, the flat- winged, and, Hnally, the roof-winged. In about three mimiles alter the shell splits, the forming
��imago extends from the rent, almost on the same plane with the (uipa, with all its membera straight, and still held by their tips within the exuvium. The imago then gradually bends backwards, and the members arc all loosened and separated. With the tip of the abdomen held within the exuvium, the rest of the body hangs extended at right angles from it. and i-emains in this |K>sition from ten to thirty min- utes or more, the wing-pads separating, and the front pair stretching at right angles from the body, and obliquely crossing the hind pair. They then gradually swell, crimp, and curl, until they form a more or less jwrfecl loop; and during all this time the legs are becoming firmer, and assuming the natural jx^sitiona. Suddenly the imago bends upward with a great deal of effort, and. clinging with its legs to the first object reached, — whether leaf, twig, or its own shell, — withdraws entirely from the ex- uvium, and hangs for the Brst time with its head up. Now the wings perceptibly swell and expand, until they are fully sti-etched, and hang flatly over the back, perfectly transparent with beautiful white veining. As they dry, they assume the roofed position, and during the night the natural colors of the si)eciea are gradually assumed.
The lime required in the transformation va- ries ; and though from the splitting of the skin, and the Aill stretching of the wings in the flat position, the time is usoally about tweotv min- utes, it may be, under precisely similar "condi- tions, five or six times as long. But there are few more beautiful sights than to see this IVesh* forming cicada in all the different positions, cliuging and clnstering in great numbers to the outside lower leaves and branches of n largs tree. In the moonlight, such a tree looks for all the world as though it were full of beautitUl white blossoms in various stages of expansion ■
That this insect, in its distribution an<l in its numbers, has been and is l>eiDg seriously affected by our civilization, must he apparent to every observer. The records show that the numbers have decreased in the successive ap- pearances of certain broods, owing lai^ely to the presence of our domestic animals in Uw woods. Then, again, the clearing of land and the building of towns and cities have all 1 " " their effect upon the decrease of this oicadsi Tiiere are doubtless many places in Brooblyi N.Y., where the insect appeared years ago, io which there will be none t present year. And similarly, I be1iev« tb^l whereas around every tree that has planted more than seventeen years, or upt land that grew trees seventeen years ago, the
��� �
