26 TRANS. ST. LOUIS ACAD. SCIENCE. 



a deep gulf between. The same soundings further show {Map 

 in the '•'"Nature" No. 391) that at a depth of from 1,000 to 2,000^ 

 fathoms there is a ridge along the bottom of the North and South 

 Atlantic ocean, near the middle and in some near conformity 

 with the shores of the continents, of which the Azores, St. Paul's^ 

 and Tristan da Cunha, are peaks still rising above water, with 

 depths reaching to 3.000 and 3,450 fathoms on either side. It is 

 possible that the American continent extended further eastward 

 than now in the region of the West India islands in Tertiary 

 times. The distribution of animals and plants (according to Mr. 

 Wallace) furnishes some evidence of such an extension. But if 

 the possibility of crossing the Atlantic (even if the bottom ridge 

 in the middle had been raised above the ocean) be not entirely 

 excluded for all prehistoric peoples, it may still be considered as 

 absolutely impracticable for the most primitive men, and until 

 times long subsequent to the first peopling of this continent. If 

 it had been possible for the Guanches, or any other people of the 

 brown band of races, to cross the ocean in prehistoric times, any 

 such mixture, considering the near identity of type and genetic 

 origin of the two branches of the same stem, would have produ- 

 ced little or no change in the red Indian race. It is perhaps not 

 improbable that the glacial men of New Jersey, retiring north- 

 wardly, may still survive in the Esquimaux. But for the rest of 

 the American red race (if indeed they belong to the same race at 

 all), it is far more probable that the actual route by which they 

 reached this continent was by the passage in the region of Beh- 

 ring's Straits ; and such passage must have taken place as early 

 as the Pliocene period. 



In this view, the discovery of human remains in the Pliocene 

 of California becomes the more credible, and confirms the hypo- 

 thesis. It is supported by a general consideration of the geogra- 

 phical distribution of the Mammalia in Tertiary times. Prof. 

 Huxley has shown the importance of taking into view the existing 

 configurations of land and sea in reference to the distribution of 

 the Mammalia, and it can be scarcely less important in reference 

 to the earliest migrations of the human races. The Elephants 

 are known to have been native to the Palaearctic province. They 

 must have reached America by that same land connection across 

 the region of Behring's Straits. Fossil elephant remains abound 



