MORPHOLOGY OF THE BAELEY GRAIN. 21 



"secreting surface to the starch endosperm. The growth of the grain 

 m such cases is not normal. The stimulation of the vegetative 

 growth has been greater than the later starch infiltration could 

 balance. The embryo and general structure of the grain have 

 attained large proportions, but the starch infiltration has been incom- 

 plete. A normally grown and matured grain of 2-rowed barley pos- 

 sesses a highly developed starch endosperm. Although this endo- 

 sperm is the first part of the grain to commence active growth, it is 

 the last to be completed m the process of ripening. If any feature of 

 climate or culture interferes with the. process of starch deposition, the 

 grain remains high in nitrogen content. This excess is due more to 

 the absence of starch than to the presence of nitrogen. There is, 

 then, a large scutellum without the corresponding bulk of starch. 

 The enzymatic secretions mtended f or the conversion of a large endo- 

 sperm are more than sufficient for the reduced starch content, and 

 both diastatic power and nitrogen content are higher than usual. 



In substantiation of this view, measurements were made tipon two 

 samples of Prmcess barley. These were grown at Huntley, Mont., 

 iu 1911. One sample was produced upon dry land, while the second 

 came from a neighboring plat which had been irrigated. The thoU- 

 sand-berry weight of the irrigated barley was 45.5 grams, while that 

 from the diy-land plat was only 30.1 grams. The scutellums in 

 either case were quite uniform. Those from the irrigated sample 

 averaged a fit tie less than 2.6 millimeters in diameter, while those 

 from the dry-laud sample fell to 2.4 milhmeters. The scutellar areas 

 were, then, 5 square millimeters for the one and 4.3 square millimeters 

 for the other. That is to say, under such conditions that the grain 

 did not tlevelop to its fullest extent the scutellar area was reduced 

 approximately 14 per cent. However, at the same time, the total 

 reduction of the grain was 33 per cent. As the hidls are more or less 

 a constant factor, the actual reduction of endosperm was probably 

 far in excess of 33 per cent. This case is l)ut a slight exaggeration of 

 the conditions of incomplete development that usually obtain over a 

 considerable part of the upper Mississippi Valley. The scutellum of 

 2-rowe(l barleys in this section is, for the most part, likely to be rela- 

 tively a greater part of the grain than is normally the case in this 

 grouj). Such barleys grown in this section are likely to show a much 

 greater converting power- ihan has been suspected. 



EFFICIENCY OF CONVERSION. 



If (he ef)ne.liisioii~ nf the uiileis be correct, the application of these 

 facts to barley j)ro(lucli<)ii and utilization is of much importance. 

 If the se/'Tction of eiizynns takes place in (he epithelial layer, the 

 gross nioriiliology of (he grnin nuist gov<'rn i(s h<'havior in gernii- 

 nutiou, incjudiiig (hii,( niodilied form of g<'rniiiui(i<>n known iis 



