Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/104

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EVOLUTION OF LIFE.

don gave rise to the Lophiodon-like animals; they divided into the Paleotherium and Anoplotherium, the roots of the odd- and even-toed orders. The Rhinoceros, of living even-toed, is the most ancient, the Horse the most modern, the Tapir being intermediate. The links binding the Horse and its ancestor, the Paleotherium, are furnished by the Hipparion and Anchitherium; these extinct animals, in , the structure of their teeth and feet, offering us a picture of what we see now in the Horse only in an embryonic condition: that is, the Horse, at one stage of its existence, is an Hipparion, while still earlier it is an Anchitherium. While the Paleotherium, descending from the Lophiodon, originated the odd-toed order, the Anoplotherium, coming from the same stock, divides into the Xiphodon and Anthracotherium branches. The Xiphodon, together with the Dichodon and Dichobune, were the earliest of Ruminants, of which there are the branches of the hollow-horned. Cow, Sheep, Goat, Antelope; the solid-horned. Deer, Giraffe; while the Camel and Llama, resembling each other in many respects, are represented by a separate stem. The Anthracotherium, the other branch coming from the Anoplotherium, divides into the stems of the Pig and Hippopotamus; nearly allied to the latter are the Sea-cow and Dugong, large herbivorous animals, found in bays and at the mouths of large rivers.

Leaving now the stem of the hoofed animals, or Ungulata, and turning to that of the Monkeys, etc., we find that many of the Prosimiae or Half-Apes are found in Madagascar, from which island the order spreads to the East Indies and Africa. These Half-Apes were regarded for a long time as Monkeys, but they differ from the true Monkeys in the number and structure of their teeth, as well as being characterized by the claw on the second toe. The different kinds of Half-Apes indicate and are the transitions to the beginnings of other orders. Thus, the Galeopithecus, flying