388 Prof. J. R, Green. On the 



The fate of the resting proteids presents no difficulty. Trans- 

 formed by the proteolytic ferment into peptone and later into as- 

 paragin, we can trace them at once into the cotyledons. There is 

 not a very great store of proteid in the seed ; and in the young plant, 

 at any rate before the development of chlorophyll, there is a con- 

 siderable amount of aspavagin. A comparison with the processes in 

 the lupin, where the transformations can be worked out without the 

 complication of the metamorphosis of a large amount of oil, indi- 

 cates the course of events. In so many other plants, too, the fact of 

 the transport of nitrogenous matter in the form of soluble amides 

 towards the seats of growth has been established, that it seems 

 unnecessary to look for any other form in this case.* 



III. The parts played by the Embryo and the Endosperm respectively in 

 the Process of Germination. 



Allusion has already been made to the statement of Sachs,f that 

 the ferments which cause decompositions in the reserve materials are 

 always formed in the young plant or embryo, and are excreted from 

 the latter into the endosperm. He quotes especially in support of 

 this view the fate of the seeds of Zea Mais, and those which, like the 

 date, have their non-nitrogenous reserves laid up in the form of cellu- 

 lose. Some years before,^ Gris claimed to have established that the 

 endosperm was, during germination, the seat of an independent life, 

 as much as the embryo was, and was by no means a passive con- 

 tributor to the latter. Some careful experiments were conducted by 

 Van Tieghem, and published by him in 1877, to which no allusion 

 is made by Sachs, but which throw an important light upon this 

 question. Part of his work, like that of Gris, was carried out on 

 Ricinus, seeds of which plant were deprived, by careful dissection, of 

 their embryos, and were exposed on damp moss for some weeks to a 

 temperature of 25 30 C. After several days of this exposure he 

 found the isolated endosperms were growing considerably, and at the 

 end of a month they had doubled their dimensions. The change was 

 caused by the enlargement of the constituent cells and the develop- 

 ment of air-spaces between them. In the interior of the cells he 

 found the aleurone grains to be gradually dissolving, and the oily 

 matter to be diminishing, though slowly. The dissolution extended 

 throughout the mass of the endosperm, and was not especially pro- 

 minent on the side that had been nearest to the cotyledons. He 



* Of. Sachs, ' Vorlesungen iiber Pflanzen-Physiologie,' Eng. Trans, by Marshall 

 Ward, p. 346. 



f Op. tit., p. 344. 



I G-ris, " Recherches anatomiques et physiologiques sur la Q-ermination." ' Ann. 

 des Sci. Nat.,' Ser. 5, Sot., vol. 2, 1864, p. 100. 



"Sur la digestion d' Albumen." ' Comptes Eendus/ vol. 84, p. 578. 



