254 INTRODUCTION TO PLANT GEOGRAPHY 



(viii) South American (Peruvian-Ecuadorian-Bolivian and two minor 

 areas). Much further extensive as well as intensive investigation should, 

 however, be carried out before (if ever) broad generalizations may be 

 indulged in where so many intangibles are involved ; definite information 

 is still largely lacking. This is why such a fascinating and potentially 

 important subject does not receive more consideration in this book. 

 But it does seem that cultivated plants mostly originated in warm regions, 

 if often in their upland areas. 



As this book is in the press, there comes news of the discovery in Jericho 

 of a Neolithic culture considerably older than any formerly known. All 

 possibility of observing signs of the ancient cultivation which must have 

 existed around the site has been destroyed by modern agriculture. But 

 the large extent of the area of sedentary occupation constitutes reasonably 

 certain proof that agriculture of some sort must have been prosecuted 

 at that time, which on the evidence of carbon- 14 dating was around 

 7000 B.C. (K. M. Kenyon voce). Among other plants, Limim appears to 

 have been cultivated in the plains of Iraq as early as around 5000 B.C. 

 (H. Helbaek voce). 



