10 



labor enabled those individuals en- 

 dowed with the proper mental capacity 

 tlie opportunity to devote time and 

 thought to other than the previously 

 dominant factor of providing the neces- 

 sary daily food. 



The probability is that the actual 

 cultivation of plants preceded the do- 

 mestication of animals, for animals 

 under close domestication must be pro- 

 vided with food. Possibly in some parts 

 of the world man did follow his flocks 

 and herds before he actually com- 

 menced tilling the soil, but it was the 

 actual planting and care of crop plants 

 that definitely removed man from the 

 nomadic class and provided the basis 

 on which higher civilizations could be 

 developed. . . . 



^ ^ i^ 4i He lii 



If, however, there be any single 

 factor that has permitted or encour- 

 aged the development of civilization 

 over and above all others, it is probable 

 that agriculture should be given this 

 credit. Just when agriculture was first 

 practiced we do not know, but we can 

 approximate the places where its de- 

 velopment first became manifest. Just 

 how the discoveries were made that 

 certain food plants could be profitably 

 grown is immaterial— they were in any 

 ease unquestionably accidental. Agri- 

 culture is not the invention of any one 

 man or any one people, but numerous 

 individuals in the dim past and among 

 di\'crse peoples in various parts of the 

 world have contributed to it, now in 

 this direction, now in that. Let it be 

 emphasized here that modern man has 

 not added a single basic food plant or 

 domesticated animal to the long list of 

 those selected and tamed by prehistoric 

 man, for every important species was 

 already in domestication somewhere in 

 the world at the dawn of recorded his- 

 tor\'. 



In tracing the origin of cultivated 



THE IMPORTANCE OF PLANTS 



plants many factors are involved. 

 Plants long in cultivation have by selec- 

 tion and hvbridi/.ation frequently as- 

 sumed strikingly different and reason- 

 ably fixed forms, as indicated by such 

 common vegetables as tlie cabbage, 

 kohlrabi, Brussels sprouts, kale and 

 cauliflower, all derived from the native 

 FAiropean Brassica oleracea Linn. It is 

 therefore sometimes difficult to prove 

 that this or that feral type is really the 

 parent form of this or that cultivated 

 plant. Were such distinct forms as 

 those of the Brassica mentioned above 

 found in nature as wild plants, most 

 botanists would unhestitatingly accept 

 them as distinct species. Convincing 

 evidence is that provided when we find 

 the parent species growing in its native 

 habitat and can positivelv prove that it 

 is the wild prototype; but here one 

 must constantly be on guard, because 

 cultivated plants introduced into re- 

 mote regions even in modern times 

 have frequently become naturalized in 

 their new homes and from their present 

 occurrence appear quite or almost as 

 though they were indigenous species in 

 their new homes. The wild ancestors of 

 nearly all cultivated plants are now 

 known and we can with confidence 

 state that this species is a native of that 

 region and that that species comes 

 from Mexico or Asia Minor or China, 

 as the case may be. Even when we do 

 not actuallv know the wild parent of 

 such important cultivated plants as to- 

 bacco, maize and the common garden 

 bean, we can with confidence state that 

 they originated in some part of North 

 or South America, and that the coco- 

 nut came originally from some part of 

 the Old World tropics. 



A brief survey of the approximate 

 places or origin of cultivated plants 

 and of domesticated animals empha- 

 sizes the striking fact that most of the 



