Tertiary Fossils of Canada, ^c. 199 



and European climates so characteristic of the time. The climate 

 of western Europe in short, would under such a state of things be 

 greatly reduced in mean temperature, the climate of America 

 would suflfer a less reduction of its mean temperature, but would 

 be much less extreme than at present ; the general effect being 

 the establishment of a more equable but lower temperature 

 throughout the northern hemisphere. It is perhaps necessary to 

 add that the existence on the land, during this period of depres- 

 sion, of large elephantine mammals in northern latitudes, as for 

 instance the Mammoth and Mastodon, does not contradict this con- 

 clusion. We know that these creatures were clothed in a manner to 

 fit them for a cool climate, and an equable rather than a high tem- 

 perature was probably most conducive to their welfare, while the 

 more extreme climate consequent on the present elevation and dis- 

 tribution of the land may have led to their extinction. 



The establishment of the present distribution of land and water, 

 giving to America its extreme climate, leaving its seas cool and 

 throwing on the coasts of Europe the heated water of the tropics, 

 would thus affect but slightly the marine life of the American 

 coast, but very materially that of Europe, producing the result so 

 often referred to in these papers, that our Canadian Pleistocene 

 fauna differs comparatively little from that now existing in the 

 gulf of St. Lawrence, though in so far as any difference subsists 

 it is in the direction of an arctic character. The changes that 

 have occurred are perhaps all the less that so soon as the Lau- 

 rentide hills to the north of the St. Lawrence valley emerged from 

 the sea, the coasts to the south of these hills would be effectually 

 protected from the heavy northern ice drifts and from the arctic 

 currents, and would have the banefit of the full action of the 

 summer heat, advantages which must have existed to a less extent 

 in western Europe. 



It is farther to be observed that such subsidence and elevation 

 would necessarily afford great facilities for the migration of arctic 

 marine animals, and that the difference between the modern and 

 newer pliocene faunas must be greatest in those localities to which 

 the animals of temperate regions could most readily migrate after 

 the change of temperature had occurred. 



It has been fully shown by many previous writers on this sub- 

 ject, that the causes above referred to are sufficient to account for 

 all the local and minor phenomena of the stratified and unstra 



