DISTINCTIONS IN CULTIVATED BARLEYS. 



29 



very extreme types the use of these variants must rest upon statis- 

 tical methods. 



At any place, the product of a variety in the same season is suffi- 

 ciently uniform to give a decided indication of the average size of 

 the kernel with 100 measurements. The size of the kernel is, how- 

 ever, but partially dependent on variety. Table VI gives a summary 

 of measurements made upon samples of grain of three varieties of 

 barley grown at various points in the United States. In this table 

 the columns marked " Greatest " and " Least " have very little sig- 

 nificance, but the averages are quite instructive. The variation is 

 remarkably uniform. The length and the lateral and dorso-ventral 

 diameters of Princess each differ about 0.5 of a millimeter in the 

 averages, while the dimensions of Primus each vary 0.4 mm. and 

 those of Chevalier II 0.2 mm. It does not necessarily follow that 

 Princess is the most variable of the three. This variety was sub- 

 jected to more extreme conditions than the other two, and in two 

 locations the development was hardly normal. 



Table VI. 



-Dimension measurements {in millimeters) of 100 kernels of each of 

 three varieties of barley. 



Variety and place of production. 



Princess: 



Huntley, Mont, (irrigated) 



Huntley, Mont, (dry land) 



McPherson, Kans 



Plainfleld, Cal 



Morris, Minn 



Primus: 



Svalof , Sweden 



St. Paul, Minn 



Bonsall, Cal 



Amarillo, Tex 



Milwaukee, Wis 



Fort Atkinson, Wis 



Chevalier II: 



Warren, Minn 



Plandreau, N. Dak 



Erie, Pa 



Plainfleld. Cal 



St. Paul, Minn 



Milwaukee, Wis 



Length. 



Great- 

 est. 



10.0 

 9.9 

 9.6 



10.2 

 9.6 



10.1 

 10.4 

 9.8 

 10.0 

 10.5 

 10.4 



10.0 



10.0 

 9.8 

 10.0 

 10.2 

 10.4 



Least. 



9.0 



8.7 

 8.8 

 9.0 

 8.7 



9.1 

 8.7 

 9.0 

 8.9 

 9.6 

 9.0 



8.3 



9.0 

 8.8 

 8.2 

 8.3 

 8.4 



Aver- 



9.3 

 9.2 

 9.2 

 9.5 

 9.1 



9.6 



9.6 

 9.5 

 9.6 



9.4 

 9.6 

 9.4 

 9.4 

 9.5 

 9.6 



Lateral diameter. 



Great- 

 est. 



3.8 

 3.4 

 3.7 

 4.0 

 3.7 



4.2 

 3.9 

 3.8 

 3.7 

 4.0 

 3.9 



3.8 

 3.7 

 4.0 

 4.0 

 3.8 

 4.0 



Least. 



3.3 

 3.0 

 3.1 

 3.3 

 3.0 



3.4 



3.4 

 3.2 

 2.9 

 3.4 

 3.4 



3.1 

 3.1 

 3.2 

 3.3 

 3.0 

 3.2 



Aver- 



3.6 

 3.2 

 3.3 

 3.7 



3.4 



3.8 

 3.7 

 3.6 

 3.4 

 3.8 

 3.7 



3.6 

 3.5 

 3.6 

 3.7 

 3.5 

 3.6 



Dorso-ventral diam- 

 eter. 



Great- 

 est. 



Least. 



2.2 

 2.0 

 2.2 

 2.3 

 2.0 



2.5 

 2.5 

 2.6 

 2.2 

 2.4 

 2.4 



2.2 



2.2 

 2.5 

 2.5 

 2.1 

 2.3 



Aver- 



2.7 

 2.2 

 2.5 

 2.6 

 2.3 



2.9 

 2.8 

 2.8 

 2.5 

 2.6 

 2.8 



2.6 

 2.6 

 2.8 

 2.8 

 2.6 

 2.7 



Of the three measurements, that of length is obviously the most 

 dependable. The actual variation is no greater, and since it is based 

 upon a much larger figure it is relatively less. Also, the two diame- 

 ters are more affected by ripening conditions than is the length and 

 are therefore less serviceable for local distinctions. The length seems 

 to be determined by varietal and climatic influences early in the life 

 of the plant, while the diameters are dependent upon the quantnVy 

 of starch infiltration at ripening time. This is well illustrated in 

 the two samples of Princess from Huntley, Mont., one of which was 

 grown by irrigation and one on dry land. The length of the kernels 



