6 BULLETIN 1074, U. S. DEPARTMENT OE AGRICULTURE. 



Harz, in 1885 (104), classified and described a large number of 

 wheats in a manner similar to that of Koernicke and Werner. The 

 common and club wheats were considered as a single species. 



Hackel, in 1887 (101), classified the genus Triticum according to 

 a key very similar to the one adopted by Koernicke and Werner. 

 Hackel recognized three species, sativum Lam., monococcum L., and 

 polonicum L. ; and three races of sativum-, namely, spelta, dieoccum, 

 and tenax. In the latter he included vulgare, compactum* turgidum, 

 and durum as subraces. 



Yilmorin, in 1889 (199), grouped the wheats into 50 sections, 

 according to their leading characters. Each section was briefly de- 

 scribed and the synonyms were given. The common and club wheats 

 were considered as one species. 



Eriksson, in 1895 (88), subdivided the botanical groups of 

 Koernicke and Werner into smaller groups which he called subvarie- 

 ties, based chiefly on the density of the spike, the thickness of the 

 kernel, and the length of the rachis. He also gives an excellent re- 

 view of the literature on wheat classification. 



Heuze, in 1896 (112), published a second edition of his "Les 

 Plantes Cereales," in which were included rather complete histories 

 and descriptions of the varieties of wheat. 



Cobb, in 1896 (69), keyed 54 varieties of wheat which he was 

 growing in New South Wales, Australia, using the leading plant, 

 spike, and kernel characters. In 1905 (72) he proposed to classify 

 wheat varieties by a microscopic examination of the aleurone layer. 

 This method, however, is impracticable for classification purposes in 

 the field, or even with certainty in the laboratory, when closely re- 

 lated varieties are considered. 



Howard and Howard, in 1909 (121), classified the wheats of India 

 largely according to the methods of Koernicke and Werner and of 

 Eriksson. They (120) also consider in detail the characters used in 

 classification. 



Eichardson, in 1913 (158) , described many of the wheats of Aus- 

 tralia and gave the history of each variety. He did not arrange them 

 in a classified order. 



The Union of South Africa in 1919 (181) published descriptions 

 and synonyms of the wheat varieties of South Africa which also 

 designated the areas where the varieties should be grown in that 

 country. 



Ducellier, in 1920 (82) , published a classification and descriptions 

 of the wheats of the Hoggar and oasis regions of Algeria, Only a 

 few varieties were fully described. 



