Endosperm of Hordeum vulgare during Germination. 7 



In the case of maize he found the first indications of action in the 

 cells lying next the scutellum, and this gradually extended along the 

 periphery of the endosperm until, within fourteen or fifteen days,, 

 this was completely emptied of its contents, with the exception of a 

 few cells in the central portions. He states that this action is not 

 due to any direct influence of the plaster, as suggested by Griiss,. 

 since it takes place also in contact with water only. In the coty- 

 ledons of Lupinus the depletion takes place even with greater 

 rapidity than in normal germination, and no difference is observed 

 whether the cut surface in contact with the water or gypsum, as the 

 case may be, is on the side adjacent or opposite to the axial organs. 

 With the isolated endosperms of maize and wheat, on the other 

 hand, Puriewitsch states that the case is different, since self-deple- 

 tion proceeds much more rapidly through the surface originally in 

 contact with the scutellum than it does from the opposite side. The 

 author also found that the depletion of the endosperm is much 

 retarded in the case of maize and wheat by the presence iii the 

 water of 2 per cent, of dextrose or glycerine, or by 3 per cent, of 

 cane sugar, and that it is completely arrested by 1*5 per cent, of 

 sodium chloride or potassium nitrate. The results on the whole are 

 regarded as contradicting the conclusions of Brown and Morris that 

 the endosperm is merely an inactive storehouse of reserve material, 

 and Puriewitsch considers that this is further borne out by the 

 behaviour of isolated endosperms in an atmosphere of water and by 

 the action of anesthetics such as ether and chloroform. Under these 

 latter conditions, he states that the endosperms of maize and wheat 

 remain unchanged, but that the depletive action recommences as 

 soon as the disturbing influences are removed. Attempts were 

 made, by applying food material in the form of weak sugar solu- 

 tions, to induce a re-deposition of reserve material in the self-de- 

 pleted tissue. These attempts were wholly unsuccessful in the case 

 of maize and wheat, but the emptied cotyledons of Lupinus albus and 

 Phaseohis multiftcrus, the bulbs of Hyacinthus orientalis, and the 

 rhizomes of Curcuma amada and Iris germanica were all capable of 

 re-forming starch within their cells. 



It will be noticed that in the recent work of Hansteen, Pfeffer, 

 Griiss, and Puriewitsch, there is a general agreement that the amyli- 

 ferous cells of the endosperm of the Grasses have a definite power of 

 digesting their reserve materials, this power being entirely inde- 

 pendent of any influence of the embryo, and the only necessary con* 

 dition for its exhibition being that the products of metabolism shall 

 not be allowed to accumulate within the endosperm. The conclusion 

 is, in fact, that the starch-bearing endosperm-cells are still living 

 units, just as are the cells of the cotyledons of Lupinus, Phaseolus, and 

 Ricinus, which are admitted on all hands to have self-depletive power. 



