SOME REMOTE ANCESTORS OF THE HORSE. 
37 
had begun. Nearly all the osteology of this animal resembles 
corresponding parts of our present horse, and it can be asserted 
with confidence that Anchitherium is in the direct ancestoral 
line of the present horse. The number of digits was three on 
all the limbs. The middle toe was large and well developed, 
while the outside ones only came to the ground, when it was 
marshy. In size this family varied from 3 to 4 feet in height, 
and was strictly a vegetable feeder, and had considerable speed. 
In the family of Anchitherium were the following genra: Hyp- 
ohippus, Anchihippus and Parahippus. These animals were 
closely allied to Anchitherium, whom they resembled very 
much in structure, the only difference being that they were 
somewhat larger. 
We now emerge from the Miocene formation to that 
of the Pliocene, and in doing so we place ourselves, as it 
were, on a more solid ground, and from this time onward can 
trace, almost without a break, the horse to his present place in 
mature. The first equine animal we meet with in the Pliocene 
Strata is that known as Hipparion, a most graceful animal 
indeed, resembling our present ass in size. The feet of Hippa¬ 
rion still possessed the extra toes, but these were now reduced 
to mere rudimentary appendages. In other respects the skel¬ 
eton was constructed on the same general plan as that of the 
present horse. The remains of this animal has been found in 
the Tertiary formation of Europe and Asia. Abundant remains 
have also been found in this country. The next animal we find 
closely related to Hipparion is an animal called Protohippur, 
and from which it does not differ in any essentiai manner. We 
now leave the Pliocene Strata, and advance upwards to that 
known as Quarternary, and in this formation we find the re¬ 
mains of horses differing in no particular manner from our 
present horse. Dr. Joseph Leidy, in summing up his conclu¬ 
sions on the extinct horses of this country during this epoch, 
says: “I think there is evidence in favor of the probability of 
there formerly having existed three distinct Species of horses 
during the Pliocene and Post-Pliocene in North America.” 
