34 THE POPULAR SCIENCE MONTHLY 



separating species from varieties, that is, their sterility when crossed 

 among themselves, or their failure to produce fertile offspring. At- 

 tempts to cross these types have never given results. 



Ordinary wheat may be divided into numerous varieties or sub- 

 species, reciprocally fertile, which are grouped about the following sub- 

 species : 



Emmer (T. dicoccum). 



Spelt (T. spelta). 



Wheat proper (T. tenax}. 



The first two subspecies differ from the third in that the ear has a 

 fragile rachis and the grains remain covered by glumes which must be 

 removed by a somewhat complicated process, whereas in the third spe- 

 cies the grains on ripening fall from the ear the rachis of which is not 

 articulated. I shall give here only what is most essential for the under- 

 standing of what is to follow. Now, it is evident that emmer and spelt 

 are inferior to true wheat because of the fragility of the rachis of the ear 

 and because of their enclosed grains. Whenever it is possible wheat is 

 grown instead of emmer or spelt. 



Not to prolong the discussion of these classifications, let us say at 

 once that wheat proper is represented in cultivation in various parts 

 of the world by a considerable number of varieties, but it is difficult 

 even for the specialist to distinguish them. One of these varieties, 

 having a non-articulated rachis (Triticum durum), the hard wheat of 

 the Mediterranean countries, is so closely related to emmer that the 

 systematic affinity of the wheats with an articulated rachis and those 

 with a non-articulated rachis can not be questioned. 2 Each year, in 

 agricultural experiment stations organized according to the principles 

 of Vilmorin, Eimpau or Svalb'f, new races are brought to light and are 

 tested out in suitable soils and climates. I do not wish to tire you by 

 a dry enumeration of all these forms; even had I the time for it I 

 should not be competent to perform this task. 



Which of all these varieties of cereals first appeared in cultivation ? 

 To this question we may reply that it is certain to-day that emmer was 

 cultivated by the Egyptians from the time of the first dynasty, or 

 about 6,000 years ago. The glumes preserved in the tombs show that 

 the grain was already at that time freed from its envelopes by the use 

 of special machines ; it was not simply flailed or tramped out by cattle. 

 Einkorn and emmer have also been found among the debris of the 

 granaries of the lake-dwellers of Switzerland. Hard wheat, which of 

 all the kinds of wheat proper most nearly resembles emmer, has also 

 been cultivated in Egypt since very ancient times. If we regard the 



a Aaronsohn, Aaron, ' ' Agricultural and Botanical Explorations in Pales- 

 tine," Bulletin No. 180, United States Department of Agriculture, 1910, Bureau 

 of Plant Industry, 64 pp., 9 pis., 12 text figures. 



