CLASSIFICATION 153 



A classification similar to that of Hackel is adopted by Ascherson 

 and Graebner (Syn. Mitteleur. Fl. vol. ii., 1901). 



The classification adopted by most of the early authors is highly 

 artificial, being based chiefly upon the characters of the ears and grains 

 alone, and often had reference to comparatively few forms, or to those 

 confined to one or two limited wheat-growing regions. 



In order to obtain a wider view of the subject, and to discover the 

 natural relationships of the cultivated wheats, I have critically examined, 

 during the last twenty years or more, living specimens from all parts of 

 the world. 



Nearly two thousand forms have been grown annually side by side, 

 and their morphological characters in the young and mature states, as 

 well as their habit of growth, ripening period, susceptibility to the attacks 

 of fungi, and other characters, have been investigated and compared. 



In determining the limits of the several races, I have not only taken 

 into account the usual morphological characters of the inflorescences, 

 but have given especial weight to the characters of the leaves and vege- 

 tative organs generally, being convinced that these have undergone little 

 change, and indicate natural genetic relationships more clearly than the 

 ears and grain, the modification of which has been the special object of the 

 cultivator from the earliest date. 



I find, for example, that the length, amount, and arrangement of the 

 hairs on the young leaf-blades are much more constant and character- 

 istic features of a race than the size, shape, and colour of its ears and grain. 



I have also taken into consideration anatomical features and the 

 results of hybridisation, as well as archaeological evidence, and the dis- 

 tribution of endemic forms in the older wheat-growing areas of the 

 Eastern Hemisphere. 



Two wild species of wheat are known, and the cultivated wheats, none 

 of which are found wild, fall into eleven natural groups. To these 

 groups I have applied the term " race " rather than the term " species," 

 although they might with equal justice be designated " cultivated species," 

 for the methods used in their grouping and delimitation are the same as 

 those adopted in the case of wild species. 



My conclusions regarding the number and classification of the races 

 of wheats are indicated below. 



With the exception of the addition of the three new races, III., VII., 

 and X., the list and the chief distinguishing characters of the groups, 

 whether termed " races " or " species," agree closely with those given 

 by Scringe and almost all authorities since his time. 



SPECIES I. T. aegilofmides, Hal. . . Wild Small Spelt. 

 RACE I. 7'. m<nuict*ccum, L. . . Small Spelt. 



