Ostriches are extremely shy and remarkably swift birds, so that they are difficult either to stalk or to ride down. When brought to bay, or when running loose in captivity, they should be approached with great caution, as a kick from their strongly clawed feet will prove fatal to an animal of the size of a jackal, if not also to a human being. The vision of these giant birds is very strongly developed and capable of sweeping the country to the distance of at least a mile; and their senses of hearing and smell are also good, although taste appears to be practically wanting. Occasionally ostriches indulge in a kind of dance; and they are also subject, when startled, to sudden collapse, which may have given rise to the old fable of their burying their heads in the sand and leaving their bodies exposed. If allowed sufficient space, ostriches thrive remarkably well in confinement; and ostrich-farming, for the sake of the lovely white plumes of the cocks, has become an important industry, not only in Africa, but in many other parts of the world. Ostrich-farming was commenced in Algeria, and by 1865 had been introduced in Cape Colony, whence it has spread northwards, while it has also been established in Egypt, southern Russia, California, Patagonia, and Argentina. The cocks are clipped regularly every eight months. THE PIED HORNBILL (_Buceros bicornis_) The hornbills, which are as large as big eagles, are some of the most extraordinary and bizarre of all birds, not only on account of the huge beaks from which they take their name, but from their strange and unique nesting-habits. In the enormous development of the beak these Old World birds are paralleled by the toucans of tropical America, although the two groups are in nowise nearly related. Such a huge and apparently unnecessary structure might at first sight seem too heavy and bulky for the bird by which it is carried; but internally the beak is generally a mere delicate tissue of bone, so that its weight is really very slight. Indeed, these enormous beaks are in most cases probably much less of an incumbrance to their owners than are the matinee hats favoured by ladies of the present day.