MOEPHOLOGY OF THE BAELEY GRAIN. 13 



and, later, Pfeffer ^ in his review of Hansteen's work. The work of 

 Hansteen is of some significance. He found that when the products 

 of convereion were constantly removed, the endosperm was able to 

 digest itself. His conclusion, however, that the endosperm is entirely 

 capable of self-digestion is rather too sweeping, especially since he 

 hhnseK foimd a very active secretion of diastase in the scutellum, the 

 existence of which function is hard to understand if it be superfluous. 

 It is much more probable that the method used by Hansteen merely 

 exaggerated the normal action of such diastase as would naturally 

 be expected to be present in the endosperm of the ripened gram, 

 for a certain mmute amount of diastase is necessarily present in the 

 cells of the endosperm to carry on the process of starch infiltration. 

 This is, however, merely that phase of diastase needed for the trans- 

 location of the starch while the barley grain is formmg. Indeed, 

 accordmg to the figures of Brencliley, the amount of diastase in the 

 growing grain decreases as the grain approaches maturity. It is 

 even reasonable to expect that not only would traces of this enzym 

 remain potentially functional in the endosperm of the ripened seed, 

 but that the coUs of this endosperm, once able to produce this fer- 

 ment, would retam such ability to some degree, even in their less 

 active condition. The effect of such smaU. quantities of local diastase 

 is not, however, to be confused with the vigorous attack that actually 

 takes place in the process of germination. The conclusions of the 

 wiitei-s are supported by those of many investigators, as above cited. 

 The theory that the aleurone layer is active in endosperm reduc- 

 tion has more in its favor than has that of the self -digest ion of the 

 endosperm. The aleuron(^ liijor is obviously high in vital energy. 

 Its cells have th(^ unmistakable aspect of active protoplasm. Their 

 nuclei are largo and present a sharp contrast to the distorted plasmic 

 centei-s of the en<losperm cells. The aspect of this layer during 

 gerniinati(m also hnuls much to the support of the hy]3othesis of its 

 b(5ing functional. As previously noted, it is not digested with the 

 (nulosyxM-m, but persists until the endosperm is almost entirely ab- 

 soibi^d. \Vh(Mi germination is carried only to that point where the 

 puip()S(is of malting have been attained, the aleurone layer is still 

 intiu^i. As shown in figure 'A, almost perfect sections of this tissue 

 may be obtain(i<l from onlinary dried brewers' gj-ains, in which the 

 (!7ilii-o starch endosperm has been dcistroycul. In still furth(M- sii])])()i t. 

 of th(» uh'ii, the disint(?gration i?i ii, newly germinatijig s(mm1 ])I()('(m^<1s 

 most rapidly dinsctly adjac(iiit lo I he ahmroiu^ layei-. A( (•(Mtaiii 

 stages this diastatic movement inay Ix^ scm-ii to have ])i()gi(^sse(l 

 imtil the thickest part of ihe en(los])('iiii is in ii, way siiii(niii<h'(l with 

 diir(wt(Ml starch ctsUs. 



' Tferifir, Wllhelm. UntcrHuchiinKon voii llftrm Iltirthold llumlijoii Im iHjtunl.sdicn liistlliil. miSKe- 

 IQhrtcn, UUrr dlo I'raaoheti dor KnllwininK dor Itcscrvesloffe uiih Hamcn. Unrlclilc, KoiiIkIIcIi t-'iicJilspho 

 Ciniell<M<hart der WlHucnwhaflcn, T>elp/.If, MathnmatlRoh-physlscho CIiiksp, Md. I'.. \>. r2\ 12.s, Iko.'). 



