86 
form of all the present ungulates. and therefore, of the Horse. It 
was associated with a form already shown --the Coryphodon and 
also with another,—the Hyracotherium. Its own name is Phena- 
cous; in size 16 was somewhat larger than a sheep, and possessed 
five hoofed toes on each foot, though possibly only three were used 
in walking ; its brain was very small. Its restored form is shown 
on the next slide. 
We have now got as far back as we can get in our researches at 
present, though of course the Phenacodus itself, on our theory, must 
have had ancestors. From this very generalized form, we are 
taught, different genera -and species of hoofed animals were 
developed along various lines, according as variations in their own 
structure fell into harmony with the physical conditions by which 
they were environed. As one geographical change succeeded 
another, those forms which, by virtue of some fortunate variation 
in their structure, were able to accommodate themselves to the 
new conditions, survived and flourished ; all who could not do this 
perished, and such must have been the case with immense numbers. 
There is a little uncertainty still prevalent as to whether the 
development of our Horse took place in the Old World, or in the 
New. Did we receive our horses from America, er did some of our 
early forms find their way over there? Probably there were 
developments in both continents. The Phenacodus however, has 
not yet been discovered on this side of the Atlantic. In those 
same old lake deposits of the Rocky Mountain district occur the 
remains of a genius they call Orohippus, corresponding to the 
Hyracotherium of the Old World, having four toes on the front 
legs and three behind ; and a little higher in the beds the Mesohippus: 
appears with three toes in front and only a rudimentary fourth. 
This leads us on to Miohippus having the fourth digit in a still 
more rudimentary condition; and thence to the Hipparion, and 
thus the chain is completed. 
About sixty were present and the usual vote of thanks was 
accorded. 
