12 



medicinal species. Yet there is much 

 evidence that leads one to believe that 

 Mexico and Central America are more 

 important as an original source of food 

 plants than are the South American 

 centers. 



American contributions to domesti- 

 cated animals were comparatively few, 

 the llama, alpaca, museovy duck and 

 guinea pig in South America, and in 

 Mexico the turkey, exhausting the list. 



Eurasia, particularly Asia as con- 

 trasted with America, yielded a very 

 much larger number of cultivated food 

 plants and domesticated animals. 

 Among the latter may be mentioned 

 cattle, the horse, sheep, goat, swine, 

 water buflfalo, yak, camel, goose, duck, 

 hen, guinea hen and pigeon. With the 

 exception of maize all the true cereals 

 are of Eurasian origin, including wheat, 

 barley, rye, oats, millet, Italian millet, 

 pearl millet, sorghum, rice, teff, ragi 

 and coix, while for convenience buck- 

 wheat may be placed here, although it 

 is not a true cereal. Among the vege- 

 tables are the turnip, cabbage, ruta- 

 baga, rape, chard, mustard, radish, beet, 

 parsnip, carrot, onion, leek, garlic, shal- 

 lot, spinach, eggplant, lettuce, endive, 

 salsify, celer}^, asparagus, globe arti- 

 choke, pea, soybean, cow-pea, chick- 

 pea, pigeon-pea, lentil, broad, hyacinth 

 and asparagus beans, taro, yam, sugar 

 cane, sesamum and various others. 

 Among the fruits the apple, pear, plum, 

 cherry, wine grape, apricot, peach, 

 prune, olive, fig, almond, persimmon, 

 quince, pomegranate, jujube, melon, 

 watermelon, cucumber, and in the 

 warmer regions the banana, coconut, 

 orange, lemon, pomelo, lime, date, 

 mango, breadfruit, jak fruit, rambutan, 

 litchi, longan, mangosteen and various 

 others. Practically all the cultivated 



THE IMPORTANCE OF PLANTS 



forage crops, including the hay grasses, 

 clovers and alfalfa, arc also of Eurasian 

 origin. 



In modern times, with steadily im- 

 proving intercommunication between 

 various parts of the world, man lias be- 

 come the most important single factor 

 in the actual dissemination of plants. 

 It can not, however, be too greatly over- 

 emphasized that it was not until after 

 the discovery of America in 1492 and 

 the succeeding period of European 

 colonial expansion that there was any 

 important distribution of cultivated 

 plants as between Eurasia and America 

 and vice versa. This fact has a very 

 striking bearing on certain persistent 

 claims that are made over and over 

 again regarding the origins of pre-Co- 

 lumbian civilizations in America, and 

 may be accepted as reasonably good 

 evidence that no ancient contacts be- 

 tween the two continents existed. The 

 earlv dissemination of cultivated plants 

 within the limits of the eastern or of 

 the western hemisphere is in itself an 

 excellent illustration of diffusion, but 

 a diffusion limited by barriers in the 

 form of broad seas that early civilized 

 man could not pass. Pioneer advanced 

 civilizations, whether in Eurasia or in 

 America, failed to keep pace with the 

 spread of early agriculture even within 

 the limits of the one hemisphere or the 

 other. The botanical, zoological and 

 agricultural evidence is wholly in sup- 

 port of the idea that pre-Columbian 

 civilizations in America were autoch- 

 thonous, gradually developed here 

 over a period of many centuries, quite 

 as parallel early civilizations were de- 

 veloped in Eurasia, the one having no 

 influence on the other until after the 

 period of European expansion follow- 

 ing the Middle Ages. 



