40 AGRICULTURAL AND BOTANICAL EXPLORATIONS IN PALESTINE. 



naturally wishes to develop forms which are not so difficult for him 

 to handle, and along this line he has succeeded in obtaining a rigid 

 rachis in barley as well as in wheat. An important difference between 

 the cultivated two-rowed barle} 7 {Hordeum distichon) and the wild 

 barley (Hordeum spontaneum) is the fragile rachis of the latter. 

 But more than this has been accomplished with wheat. Forms have 

 been developed in which the grains are very readily removed from 

 the glumes. In barley and oats this has not been done to the same 

 extent. We have, it is true, naked varieties of these two cereals, but 

 these varieties have not been extensively cultivated, doubtless on ac- 

 count of their relatively smaller yield, and until a comparatively 

 recent date their cultivation has been confined to the Orient. In 

 wheat, on the contrary, naked grains and a rigid rachis are the 

 general rule, these two characteristics differentiating the cultivated 

 forms from the primitive type and making the former incapable of 

 perpetuating itself without the intervention of man. 



CULTIVATED WHEATS WITH A BRITTLE RACHIS. 



Among the known cultivated wheats there are three that still 

 retain the brittle rachis: Einkorn (Triticum monococcum) , emmer 

 (Triticum dicoccum) , and spelt (Triticum spelta). 



It is known that the cultivation as grain crops of einkorn, emmer, 

 and spelt is steadily decreasing. An attempt has been made in com- 

 paratively recent times both in this country and in Russia to cultivate 

 einkorn and emmer as forage plants. It is interesting to note that, 

 except for these attempts, these wheats are cultivated to-day only by 

 the Basques, the primitive Swabians, the Serbes, and that peculiar 

 people the Bactrians of Persia. 



The cultivated wheats with a rigid rachis are therefore derived 

 from the wheats with a brittle rachis. But of the three species which 

 have this common character, which one shall we select as the proto- 

 type and why make this selection to the exclusion of the others? 



EINKORN AND ITS PROTOTYPE DISTINCT FROM OTHER WHEATS. 



More than fifty years ago Balansa discovered Triticum monococ- 

 cum aegilipoides in the wild state. This differs from the culti- 

 vated Triticum monococcum only in minute characters and is without 

 doubt its prototype. Balansa believed that he had found the progen- 

 itor of the cultivated wheats, an opinion that Haussknecht also ac- 

 cepted at the time. But experiments in crossing undertaken more 

 than thirty years ago by Vilmorin led him to assert that whereas all 

 the other species of wheats crossed with each other perfectly and gave 

 mongrels, or fertile offspring, he had never succeeded in crossing 



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