74 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 Rumi- 
nants, 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 Ano- 
plotherium, divides into the stems of the Pig and Hippo- 
potamus; 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 Prosimiz 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 char- 
acterized 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 
