Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/94

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EVOLUTION OF LIFE.

great number of neck-bones (cervical vertebrae), in the light character of the bones of the head, together with the structure of the foot, is probably the most bird-like of reptiles, and is to be considered together with the Megalosaurus, Hypsilopodon, and other Dinosauria, as the representative of the ancestors of birds. It is not possible to say exactly which Dinosaur was the progenitor of birds, but as the Compsognathus is the most bird-like of reptiles, we take it as our example. The idea of birds coming from reptiles is suggested by the following facts: 1st, existing birds have much in common with existing reptiles; 2d, birds and reptiles, at an early period of their existence, cannot be distinguished from one another, as in the case of the embryo chicken and turtle; 3d, the most ancient bird (Archeopteryx) is very reptilian, while certain extinct reptiles (Dinosauria) are very bird-like. These statements are facts accepted by naturalists, whether they are evolutionists or not; they seem to us to harmonize in warranting the conclusion that birds are modified reptiles. Among existing birds the Ostrich family is particularly interesting, as they seem to be the representatives of a class once much larger. The Ostrich is found in Africa, the Rhea in South America, the Emeu in New Holland, and the Cassowary in the East Indies. They are known as the running birds, their wings being 'quite rudimentary. With the Ostrich family is generally placed the Apteryx of New Zealand. It is a little bird, the miniature of the gigantic Dinornis, which stood nearly twice as high as the Ostrich. The Dinornis has died out very recently, if it be indeed extinct. This very wide distribution of the Ostrich family suggests that the order was once much larger, extending all over the earth, and that the present representatives are the sole survivors. This seems more natural than to suppose that the Ostrich, Rhea, and Cassowary appeared independently in parts of the earth so remote. If this view be correct, then