122 VARIOUS FOOD-PLANTS 



us with energy which shall be immediately available at any 

 moment for the work of life. 



45. Food-plants in general. When considering the cereal 

 grains, we found tliat important facts regarding their special 

 value and present use were explained bj' the original geo- 

 graphical range and economic history of the species. We 

 have now to conclude our study of food-plants by a com- 

 parison, from this point of view, of the other kinds with 

 these, so that we may arrive at some further general itleas 

 concerning them. 



In the tal)ular view on pages 120-121 is given for each of 

 the species already referred to, a brief statement of its native 

 home and period of earliest cultivation, acc(jrding to the 

 opinion of recent authorities. Where these are doubtful 

 an interrogation mark in parenthesis has ))ecn placed after 

 the point in question. 



46. The primitive centers of agriculture. We have al- 

 ready seen that the three grains, wheat, i-ice, and maize, which 

 have played a supremely important i)art in th(> liistory of 

 mankind, are each native to a region which is widely separ- 

 ated from the homes of the other two, — wheat being in- 

 digenous to Mesopotamia, rice to soutlK.-astern Asia, and 

 maize to tropiral America. 



There is abundant evidence to show that it was in these 

 regions, and in the lands inunediately adjacent, that agri- 

 culture was hrst systematically pursued, and tluis made ]ios- 

 sible the development of the great civilizations of antiquit>-. 



It is certainly a fact of profound significance in human 

 history that wheat, the most valual)le of the grains, slujuld )>e 

 native to a region so near the junction of the three continents 

 of the eastern hemisphere. Antiquarian scholars are of the 

 opinion that from the fertile valley of the Tigris and Eu- 

 phrates as a center, agriculture, with the civilization which 

 it implies, extended to all the great ])eoi)les of Africa, Europe, 

 and soutliern nm\ western Asia. A more I'estricted civiliza- 

 tion of later development and less impoitance was that which 

 arose in the valley of the Hoanglio and Vangtse-Kiang, and 

 formed the beginning of f Ik^ prescul ( 'hinese Empire. Still 

 later, although many cenlmies before I he coming of Cohun- 



