30 BULLETIN 137, U. S. DEPARTMENT OF AGRICULTURE. 



in the two samples was practically identical, while the diameters 

 showed the greatest variations found within a variety. 



The weakness of all grain measurements is not in the variation 

 but in the fact that the interval between varieties is not great. The 

 total range of averages is not large, and while many selections may 

 be distinguished, a great many more must remain inseparable be- 

 cause of identical or nearly identical dimensions. 



WEIGHT OF THE KERNEL. 



The weight of 1,000 kernels is a determination that has been con- 

 sidered indispensable in the appraisement of exhibition samples, 

 and it is also a very useful record in plant breeding. From the 

 nature of this factor it is to be expected that it will vary with con- 

 ditions and culture, but usually the variations are more or less par- 

 allel. In this investigation certain varieties have always been found 

 relatively high and others relatively low in kernel weight, regardless 

 of location or season. The character is, however, a varietal one and 

 not often useful in separating related strains. 



COMPOSITION OF THE KERNEL. 



The varietal ' character of any barley, as far as composition is 

 concerned, is subservient to climatic conditions. For example, if 

 it is grown in California it will be much lower in nitrogen than if 

 grown in Minnesota. The average differences in the composition 

 of all varieties grown at two places is often greater than that be- 

 tween the two most extreme varieties at either place. Despite this 

 fact, there is an actual varietal tendency. The Svanhals is reported 

 in Sweden to be relatively high in nitrogen for a 2-rowed barley, and 

 it is also high in this country. Analyses of samples of California 

 feed from many States in the West and in the Plains area showed 

 that this variety was always lower in nitrogen than other 6-rowed 

 forms. Le Clerc and Wahl (17) found that the average protein 

 content for Bay Brewing from all points was 10.73 per cent, while 

 for the ordinaiw 6-rowed variety it was 11.86 per cent. 



It is doubtful whether a factor with such wide and easily influ- 

 enced limits can be made to be of assistance in the separation of 

 strains, save in exceptional cases. It can, however, be used in the 

 description of varieties, and may be of much importance in the 

 selection of sorts adapted to satisfy market demands. 



PIGMENTATION. 



Color is one of the most easily determined characters of barley, 

 but, unfortunately, it is also one of the most treacherous distinctions. 

 The occurrence of pigments in certain cases and in certain tissues is 

 undoubtedly hereditary and is transmitted unfailingly from genera- 



