Identifier: americanauniver08beac (find matches)
Title: The Americana : a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc. of the world
Year: 1903 (1900s)
Authors: Beach, Frederick Converse, 1848-1918 Rines, George Edwin, 1860-
Subjects: Encyclopedias and dictionaries
Publisher: New York : Scientific American Compiling Dept.
Contributing Library: Robarts - University of Toronto
Digitizing Sponsor: University of Toronto

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
food becomes difficult to obtain,the animal being compelled to devote nearly allits time to getting enough to eat. Cause of the Evolution.— The evolution ofthe horse, adapting it to live on the dry plains,probably went hand in hand with the evolutionof the plains themselves. At the commencementof the Age of Mammals the western part of theNorth American continent was by no means ashigh above sea-level as now. Great parts of it hadbut recently emerged, and the Gulf of Mexicostill stretched far up the valley of the Mis-sissippi. The climate at that time was probablyvery moist, warm and tropical, as is shown bythe tropical forest trees, found fossil even asfar as Greenland. Such a climate, with the lowelevation of the land, would favor the growthof dense forests all over the country, and tosuch conditions of life the animals of the be-ginning of the Mammalian period must have beenadapted. During the Tertiary the continent wassteadily rising above the ocean-level, and at the HYlOHIlPUS.
Text Appearing After Image:
SKELETON FROM MIDDLE MIOCENE BEDS, NEAR PAWNEEBUTTE, COLORADO. HORSE same time other influences were at work tonuke the climate continually colder and drier.I he coming on of a cold, dry climate restrictedand thinned the forests and caused the appear-ance and extension of open, grassy plains. Theancient forest inhabitants were forced either toretreat and disappear with the forests, or toadapt themselves to the new conditions of life.The ancestors of the horse, following the lattercourse, changed with the changing conditions,and the race became finally as we see it to-day,one of the most highly specialized of animals inits adaptation to its peculiar environment. Atthe end of the Age of Mammals the continentsstood at a higher elevation than at present, andthere was a broad land connection between Asiaand North America, as well as those now exist-ing. At this time the horse became cosmopoli-tan, and inhabited the plains of all the greatcontinents, excepting Australia. It is a question wh

Note About Images