Читать книгу Intelligence in Plants and Animals онлайн

96 страница из 113

Although Cicadas abound most upon the oaks, yet there seem to be no trees or shrubs that are exempt from their attacks, unless it be the various species of pines and firs. The punctured limbs languish and die soon after the eggs are laid, and as often happens are broken off by the winds; but when this is the case the eggs never hatch, for the moisture of the living branch seems necessary for their proper development.

The eggs are one-twelfth of an inch in length, and one-sixteenth of an inch through the middle, but taper to an obtuse point at each end. They are of a pearl-white color. The shell is so thin and delicate that the form of the inclosed insect can be seen before the egg is hatched. One writer claims that fifty-two days, and others that fourteen days, constitute the period required for the hatching of the egg.

When it bursts the shell the young insect is one-sixteenth of an inch long, and is of a yellowish-white color, excepting the eyes and the claws of the fore-legs, which are reddish. It is clothed with small hairs. In form it is grub-like, larger proportionally than the parent, and provided with six legs, the first pair being very large, shaped like lobster-claws, and armed beneath with strong spines. Little prominences take the place of wings, and under the breast is a long beak for suction. Its movements, after leaving the egg, are very lively, and nearly as quick as some of the ants. But after a few moments their instincts prompt them to reach the ground. They do not attain this end by descending the body of the tree, nor by casting themselves off precipitately, but, running to the side of the limb, deliberately loosen their hold and drop to the ground, making the perilous descent with the utmost safety. This seems almost incredible, but it has been repeatedly observed by scores of honest witnesses.

Правообладателям