60 REV. PEOF. G. F. WRIGHT, ON THE INFLUENCE OF THE 
elevation of land over all the Northern hemisphere. This is 
evident from so many facts that we do not need to pause here 
for their full presentation. Briefly stated, the facts are that all 
the northern part of America stood at an elevation of between 
2.000 and 3,000 feet above that which it has at present. The 
same is also true of Northern Europe. During the Tertiary 
Period, also, as is well known, all the high mountain chains of 
the world received their present elevation ; marine strata of the 
Middle Tertiary Period being frequently found at an elevation 
of from 10,000 to 15,000 feet above the sea. In the latter part 
of the Tertiary Period, also, the animal species which now 
occupy the earth attained their present characteristics, while a 
large number of closely allied species which attained great 
prominence flourished for a while, but in connection with the 
vicissitudes of the Glacial Epoch either became extinct, or shifted 
the centre of their field of occupation. From the evidence of 
man’s co-existence with them during the closing stages of the 
Glacial Epoch, it would appear that he, too, came upon the scene 
soon after the close of the Tertiary Period, and was distributed 
over the surface of the earth while the elevation of the Tertiary 
Period still furnished land communication between the Eastern 
and Western hemispheres. 
Presumably this land communication was between Asia and 
North America in the region of Behring’s Straits and Behring’s 
Sea. Here an elevation of a few hundred feet would lay hare 
a vast tract of land furnishing pasturage for animals and all 
the means of sustenance that primitive tribes would demand. 
The same amount of elevation would also lay bare a border of 
the American continent all the way to California, which is now 
only slightly submerged ; and open the way for the dispersal 
through America both of man and of the now extinct animals 
with which he was associated. 
Clear evidence that this was the course of events is shown by 
man’s association with the mammoth. The remains of this huge 
species of elephant are found in great abundance in connection 
with those of man, not only over North-Western Europe, 
whither they had migrated in one direction from their original 
centre, hut all over Northern Siberia and the islands adjoining, 
and onward to Alaska and over the northern part of the 
United States, penetrating on the western coast as far south 
as Mexico. 
With these things in mind, we may now see how important 
a factor the Glacial Epoch probably was in affecting the 
destinies of man. This elevation of land at the beginning of 
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