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DOME-LIKE HOUSE OF CICADA.

Longitudinal Section Showing Pupa in Two Positions.

In localities where the soil is low and swampy, a remarkable chamber is built up by the larva, where the pupa may be found awaiting the time of its change to the winged state. These chambers were first noticed by S. S. Rathvon, at Lancaster, Pa., and are from four to six inches above the ground, and have a diameter of one inch and a quarter. When ready to emerge the insect backs down to an opening which is left in the side of the structure on a level with the surface of the ground, issues forth and undergoes its transformation in the usual manner. This peculiar habit of nest-building, which is so unlike what is customary with the Cicadidæ, or with Hemiptera in general, points to a high degree of intelligence among these insects, showing a remarkable ability to adapt themselves to environing circumstances. Undue moisture would be prejudicial to the pupa, as the larva seemed to know, through the guidance of the same dumb and unerring instinct which teaches it to cement its underground dwelling, but would that same instinct teach it to construct so wonderful a dome-like house as the one described for the preservation of its after-life, and one so eminently fitted by its position, shape, size and entrance to secure the necessary shelter, warmth and air for its protection and development? I apprehend not. Nothing short of a reason, similar to that in man, but differing in degree, would enable it to grasp the situation in which it found itself to be placed when nearing its final change, and plan with the view of carrying out the ultimate aim of its existence.