14 STEPPES AND DESERTS. 



around the colossal ruins of the Aztec fortress which rises 

 in the wilderness, like an American Palmyra, on the solitary 

 banks of the Gila. The long-horned Rocky Mountain Sheep 

 abounds on the arid limestone rocks of California. The Vicunas, 

 Huanacos, Alpacas, and Lamas, belong to South America ; 

 but the two first named of all these useful animals, i. e., the 

 Buffalo and the Musk Ox, have retained their natural 

 freedom for two thousand years, and the use of milk and 

 cheese, like the possession and cultivation of farinaceous 

 grasses, ( 27 ) has remained a distinguishing characteristic of 

 the nations of the old world. 



If some of the latter have crossed from northern Asia to 

 the west coast of America, and if, keeping by preference to 

 the cooler mountain regions, ( 28 ) they have followed the lofty 

 ridge of the Andes towards the south, their migration must 

 have taken place by ways in which they could not be accom- 

 panied by their flocks and herds, or bring with them the 

 cultivation of corn. "When the long shaken empire of the 

 Hiongnu fell, may we conjecture that the movement of this 

 powerful tribe may also have occasioned in the north-east of 

 China and in Corea a shock and an impulse which may have 

 caused civilized Asiatics to pass over into the new continent? 

 If such a migration had consisted of inhabitants of the 

 Steppes in which agriculture was not pursued, this hazardous 

 hypothesis (which has hitherto been but little favoured by 

 the comparison of languages) would at least explain the 

 striking absence of the Cereals in America. Possibly one 

 of those Asiatic priestly colonies whom mystic dreams 

 sometimes impelled to embark in long voyages, (of which 



