68 The American Geologist. January, 1892 
been found. When Europeans landed on the new continent the 
horse was an unknown animal to the natives. So it had evidently 
long been extinct. 
All the horses now found in either North or South America came 
from stock originally brought over by Europeans. But here 
we have evidence in the association of a human implement and a 
horse’s skull that man and horse had lived together, and the 
peculiar fracture of the skull of the latter leads to the belief that 
the animal had met its death at the hands of man. 
This fact opens several questions. What became of the race 
of horses that once lived on the continent? Were they exterm- 
inated by savage man as civilized man has exterminated the 
bison? Did they once serve as beasts of burden or were they 
used only as food? Were they wild or domesticated? 
It seems probable that they were not used for any other pur- 
pose than as food, and that they existed only in a wild state, for 
it is scarcely reasonable to suppose that having once been used by 
man and so domesticated their use would ever have been forgotten 
or the breed allowed to die out, Neither is it probable that they 
were exterminated solely by the agency of contemporaneous man, 
for we know that in spite of the use of the bison by the Indians of 
North America their numbers did not decrease to any great ex- 
tent. It was only when civilized man began his destructive work 
that the bison began to disappear. 
What then was the cause of the disappearance of the horse? 
If it were demonstrated that this early horse existed prior to the 
ice-age his disappearance might be attributed reasonably to the 
cold that prevailed, or to some of the attendant conditions. 
While Dr. Cope considers the ‘‘Equus beds” as of Tertiary age, 
Messrs. Gilbert, Russell and McGee have given much evidence 
that they are middle or late Quaternary. The coérdination of the 
strata of the southern states with the drift sheet of the northern 
has not yet been elucidated. The early Pleistocene was connected 
by a link which has not yet been discovered, with the latest 
Pliocene. Whether that link consisted largely of the advent of 
the ice-age, or the outburst of the Quaternary eruptive forces that 
characterize this date in the western and Pacific states, or both of 
these cotemporaneously, it is evident that it was marked by great 
physical changes such that the habitability of the country by 
many of the larger mammals was destroyed. 
Mr. Cope has given a description of this skull in the October 
number of the American Naturalist. He considers it Equus 
excelsus Leidy,and remarks that it is the first that has come to light 
inthe United States. 
THE SPANISH GOVERNMENT HAS DETERMINED to hold a _his- 
torical and archeological international exhibition next year, and 
especially honors the United States by its invitation and applica- 
tion for aid. The Spanish exposition will in no wise compromise 
