CULTURE PERIOD AND NATIVE HOME 125 



Old ^^'orkl before the beginning of the Christian Era, or in 

 the case of New World forms, to have been in cultivation, 

 at most only a few centuries before Columbus discovered 

 America. By plants of recent culture are to be understood 

 such as have been introduced into agriculture since the discov- 

 ery of America. A glance at the tabular view will show that 

 none of these '' modern " or " recent " plants are native to 

 regions within or near to the primitive centers of agriculture. 

 Some of these plants occur wild in both the Old and the New 

 World; namely, raspberries, the garden currant, and the field 

 mushroom. Those confined to the Old World are buckwheat, 

 rhubarb, and sago: those of the New World are the butter- 

 nut, hickory, pecan-nut, Jerusalem artichoke, garden straw- 

 berry, and northern fox-grape. 



The Brazil-nut and "carrageen" are the only other food- 

 plants included in our list. Of these the wild product so 

 fully satisfies the demand, that the plants have never been 

 cultivated, and their native homes are thus without special 

 significance in the matter under consideration. It is, how- 

 ever, a confirmation of the principle ahove stated, that no 

 plant of any considerable agricultural importance has been 

 derived from regions Avhich are remote from the primitive 

 centers of agriculture, or cut off from early communication 

 with them, even though the climate may be highly favorable. 

 This is true of South Africa, Australia, and New Zealand. 



The facts we have stated show plainly that the native home 

 of a cultivated food-plant stands in close relation Avith its 

 importance to mankind. That is to say, just as we found 

 that a knowledge of the chemical composition of plant-foods 

 enabled us to understand in what manner and how much 

 they were used, so now it appears that to know the original 

 geographical ranges of cultivated plants helps us to explain 

 the time and area over which their use has extended. Of 

 course, many other considerations often need to be taken 

 into account in order satisfactorily to explain all that is 

 known regarding the differences in extent and duration of 

 such usefulness. What should be insisted upon is that geo- 

 graphical facts are of fundamental importance in discussing 

 the economic history of food-plants. 



