The members of this family are spread over the whole of the Eastern Hemisphere and New Holland, being particularly numerous in Africa and India, while the more northern portions possess but one species. All, without exception, are inhabitants of the woods, and rarely leave the shelter of their favourite trees, except during the period of migration, or when, as with the more southern species, they are wandering for a short season over the face of the country. In disposition they are timorous, restless, and extremely averse to associate with other birds, indeed, they frequently avoid the society of their own congeners. Their life may be described as an incessant and noisy search for food, in pursuit of which they hurry rapidly from tree to tree and place to place. Insects and larvæ afford them their principal means of subsistence, and hairy caterpillars (avoided by most other birds) are with them favourite tid-bits--the hairs from the bodies of these caterpillars adhere to the coats of the Cuckoo's stomach, and become, as it were, embedded by the process of digestion. Many also consume small reptiles. Some species prepare suitable receptacles for their young; but the greater number deposit their eggs in the nests of other birds. THE COMMON CUCKOO. The COMMON CUCKOO (_Cuculus canorus_) represents a group possessing a slender body, a small, weak, slightly-curved beak, long, pointed wings, a long, rounded tail, short, partially-feathered feet, and plumage of a sombre hue. The male is deep ash-grey, or greyish blue, on the mantle, and greyish white, marked with black, on the under side; the neck, cheeks, throat, and the sides of the neck, as far down as the breast, are pure ash-grey; the quills of the wings leaden black, and those of the tail black, spotted with white. The eye is of a bright yellow; the beak black, but yellowish towards its base; and the foot yellow. The female resembles the male, but has scarcely perceptible reddish stripes on the back and under side of the neck. The length of the male is fourteen inches; breadth twenty-four and a half; length of wing, nine inches; length of tail, seven and three-quarter inches. The female is about an inch shorter. This Cuckoo frequents almost every part of Europe, Asia, and Africa, and breeds in all northern portions of the Eastern Hemisphere; it only visits India, China, Java, the Sundainu Islands, and South-western Africa in the course of its migrations. In England it usually appears about the middle of April.