HOLMES DISTRIBUTION OF THE HUMAN RACE. 29 



It would, therefore, appear most probable (if not quite certain) 

 that the Pacific coasts from the Aleutian Islands to the isthmus 

 were peopled by the ancestors of the red Indian race before the 

 region to the eastward of the Sierras and Rocky Mountains was 

 occupied by them. The ocean barrier at the isthmus once cut oft; 

 the Pliocene men would readily follow the mastodons and camels 

 to the western coasts of South America, and thence ascend to the 

 higher plateaus and spread over the eastern slopes of the Andean 

 ridge. It is along these coasts and in the lower lands of Mex- 

 ico, Central America, and Peru, that the oldest remains of fixed 

 habitation and civilization are found. Not that these remains 

 were the work of the very first settlers, or of peoples that were 

 then migrating from the north ; but that these remains may be 

 taken as some evidence that these parts of the continent had been 

 the seats of longest occupation, where higher stages of progress 

 had first been attained to. The oldest of these civilizations must 

 have been quite recent in comparison with the first date of human 

 occupation : those of the elevated basins of Mexico and Cuzco 

 were still flourishing at the discovery of America. The older 

 seats of civilization in Central America had been abandoned long 

 before the arrival of the Spaniards. When the earthworks of the 

 Ohio Mound-builders were first discovered, they were covered by 

 ancient forest growths, and showed the same signs of high anti- 

 quity that they now do. These earlier peoples and civilizations 

 appear to have spread northeastwardly from Central America 

 ■over northern Mexico and into the valley of the Mississippi ; 

 whence their successors seem to have retired southwardly, again, 

 at a more recent period, or to have become extinct in that area 

 when more barbarous tribes pressed down upon them from the 

 northern regions. There is nothing yet known by which it can 

 be determined whether the most ancient Mound-builders of the 

 Ohio valley, or the Stone-builders of Palenque and Uxmal, were 

 the more ancient ; but the simpler earthworks and ruder imple- 

 ments of the former would seem to indicate a lower stage of pro- 

 gress, if not a higher antiquity. The mounds and other remains 

 of towns in southeastern Missouri and in other southern States, 

 and especially the pottery and other implements found therein, 

 indicate a period much more recent than that of the earthworks 

 of the Ohio valley ; and they exhibit a stage of progress in arts 



