THE IDENTIFICATION OF VARIETIES OF BARLEY. 3 



discovered during the progress of the work, and (4) to form the 

 basis for a discussion of all the agricultural varieties grown upon 

 the farms in America. 



There is also a distinctly experimental phase to the work. Cer- 

 tain types of barley are likely to succeed in certain areas, while others 

 are as definitely unsuited to specific regions. A more thorough co- 

 ordination of the work of the various stations with reference to types 

 of varieties should be o£ service in experimentation. It is possible 

 also that a study of the existing forms of barley may be useful to 

 pathologists in determining the degrees of immunity to disease of 

 the various groups. 



REVIEW OF THE LITERATURE. 



Although the genus Hordeum to which the cultivated barleys be- 

 long obtains its name direct from the Latin name, there is little to 

 be gained in a review of the literature before Linnseus. Almost all 

 of the pre-Linnsean authors recognized the distinction between 2- 

 rowed and 6-rowed barleys. Linnseus (1753, p. 84—85), amplifying 

 his scheme of 1748, described six forms, four species and two varie- 

 ties, viz : 



Hordeum vulgare. Hordeum distichon. 



Hordeum vulgare eoeleste. Hordeum distichon nudum. 



Hordeum hexastichon. Hordeum zeocriton. 



Gustav Schuebler (1818) named seven species, using in their sepa- 

 ration fertility, color, adherence of flowering glumes, and density. In 

 this work he made for the first time the distinction between nutans 

 and erectum-. These were subdivisions of distichon and not of the 

 rank of the seven species. 



Seringe (1819) suggested four species, hexastichon, vulgare, zeo- 

 criton, and distichon. In 1841 he followed closely the scheme of 

 Linnseus, although he made several subdivisions. 



Up to and including Seringe, all treatments were based upon 

 limited collections. As a greater number of varieties were assem- 

 bled, the problem of classifying them called for a marked expansion 

 of the systems. The first of the more modern treatments was that 

 of Heuze in 1872. This was really a remarkable contribution, and 

 in both arrangement and material was the obvious forerunner of 

 both "Die Saatgerste" of Kornicke (1882) and of the treatment 

 in the " Handbuch des Getreidejoaues " of Kornicke and Werner 

 (1885) . " Die Saatgerste," as later amplified under the title of " Die 

 Arten und Varietaten des Getreides " in the " Handbuch des Ge- 

 treidebaues" (Bd. 1), has been widely accepted as the best modern 

 authority. In part this credit is well bestowed. Kornicke used the 

 variety as a unit, and although he sometimes went too much into 



