Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/208

158 being half Hare half Rabbit. According to Prof. Haeckel, the pairing of the male Goat and female Sheep is very common in Chili, their progeny being fertile; while the Ram and female Goat rarely pair, and then without offspring. It is well known that some animals when confined in menageries, etc. will not breed. We see, therefore, upon what slight differences reproduction depends.

The absence of links between the different forms of plants and animals is often urged as an objection to the theory of the Evolution of Life. The not finding of links is due very often to not looking for them in the right place. Thus, a pigeon-fancier, not finding a link between the Carrier and Pouter, might have argued some years ago that they had descended from the primitive Carrier and Pouter, of whose origin he knew nothing. But it is well known now that these pigeons are the posterity of a common ancestor, the Rock Pigeon. Hence the transitional forms are between the Rock Pigeon and the Carrier, between the Rock and the Pouter. We have tried to show that the Struggle for Existence produces a divergence of character, so that in the course of time the posterity differs greatly from the parent stock. Now, if the intermediate animals die out, forms are left which have little in common with existing animals. In this manner may be explained the existence of such isolated unique forms as the Elephant, Sloth, Giraffe, so readily distinguished by their striking peculiarities. The Capuchins, among the South American monkeys, on the contrary, exhibit such a number of varieties, species, and genera that it is almost impossible to classify them, the transitional forms being so numerous. Many have argued that too much time is required in the development of the animal and vegetal kingdoms through the Survival of the Fittest. Physical and Geological science cannot at present assign any definite age to the Earth; and, from the rate at which deposits are formed at the present day, millions and