4 
CULTURE PERIOD AND NATIVE HOME 125 
Old World 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 above stated, that no 
plant of any considerable agricultural importance has been 
derived from regions which 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 with 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. 
