ORIGIN OF DOMESTICATED ANIMALS 213 
The best of evidence exists to show that the modern horse 
has developed from a diminutive five-toed ancestor not much 
larger than a jack rabbit. Fig. 37 shows this animal restored, 
and compared in size with the head of the common horse. The 
story is too long to be recited here, but should be read in col- 
lateral literature. Space permits us to note only the significant 
fact that actual relics have been found in western North America, 
and are still in existence, showing the entire evolution of the 
horse from the little five-toed animal just mentioned, up through 
the forms with three toes, to the present form with one, the so- 
called “splint bones” at the side being all that is left of the 
original digits II and IV, all traces of Nos. I and V having 
long since disappeared. Along with this reduction in the number 
of toes has gone a gradual increase in the size of the body and 
a hardening of the teeth till the readaptation was complete from 
a small and probably timid animal living on soft feed and low 
ground to the swiftest of all animals, of good size, subsisting on 
upland grasses and prairies and fitted for locomotion on hard land. 
More than to any one else we are indebted for this history to 
Professor H. F. Osborn of the American Museum of Natural 
History, New York, who is now completing his material for an 
almost perfect history of the horse, from the diminutive ancestor 
down, or rather up, to the modern domesticated form, with many 
distinct types between, but merging into each other gradually 
and distinguished by differences almost imperceptible. Differ- 
ing though they do from the modern horse, these many forms 
are clearly horselike, and, moreover, they are connected by un- 
mistakable links that bind them all together as one of the 
greatest evolutionary achievements of the earth. 
As has been intimated, this history has been largely traced 
through fossil remains found in western America, especially in 
Wyoming. Europe affords evidences of the same evolutionary 
processes, and without a doubt the same course of development 
could be traced in Asia, as will likely one day be done, if exten- 
sive explorations are made in that country. 
