4 
INTRODUCTION. 
In the Tertiary Age, North America presented a very different aspect from that of to-day. 
The sea covered nearly the whole of that portion of the United States south of the junction of the 
Ohio river with the Mississippi. Highlands were visible in the Tennessee region, and in parts of 
Arkansas and also of Mexico, but a greater portion of the section named was under the sea. In ' 
Kansas, and westward to the Rocky Mountains, there were immense lakes, which, drying up, left 
in their beds the remains of many creatures whose species are now extinct, but which are illus¬ 
trated in this work. What was equally singular is the fact that all of North America possessed a 
mild climate, and was covered by a luxuriant vegetation of marvellous diversity, with tropical plants 
growing in profusion along the shores of the Arctic sea. The giant trees of California are the 
representative types of the forests that distinguished the Tertiary epoch. This period is also 
called the “ Age of Mammals ” for the reasons above given. Among the numerous species, the 
prototypes of those now existing, and which have undergone wonderful change through constant 
progression, was the horse, which appeared during this era, but very dissimilar in form from that 
which it has since assumed. The primitive horse was scarcely larger than a fox, and had three 
hoofed toes on the hinder feet, and no less than four similarly hoofed toes on the fore feet. 
Remains have also been discovered showing the horse to have increased in size to that of 
a sheep, when one of the toes on each fore foot was dropped; and still later it developed into a 
single-hoofed animal, the size of an ass, with side toes scarcely long enough to touch the ground. 
The Quaternary Age is that in which we live, but it has already extended over a very long 
period of time, and far beyond the grasp of transmitted history. It has been within this age that 
some of the mightiest forces and catastrophes of nature have combined to precipitate extraordinary 
changes both in climate and conditions. By reason, as is supposed, of the shifting of the declina¬ 
tion of the earth, a great deluge of ice was sent crashing down over the northern regions of both 
continents, converting the mild climates theretofore existing into perpetual frost, as we now find it. 
Not alone this, but the animals which roamed those regions were destroyed by the moving fields 
of ice and snow ; such monsters as the mammoth, mastodon, woolly rhinoceros, sabre-toothed 
tiger, cave bear, Irish elk and other species, became extinct during this period, whose bones, how¬ 
ever, are plentifully found deeply imbedded in the earth upon the spot where they so suddenly per¬ 
ished, to teach us how wonderful are the ways of Providence, and how feeble is the power and 
understanding of man, but for whose care God is ever watchful and considerate. 
