I5Y JAMIvS M. I'KTUIK. 129 



Albumoses and peptones were identified in plants by 

 Schulze* and Neunieisterf in 1894, and in the unripe seeds 

 by Frankfurtt, Nedokutschajeff^, and Zaleski^l. 



It seems most probable, then, that the highly complex 

 globulins and albumins of the seed-reserves are formed, iu 

 great part, from these proximate cleavage-products which 

 are still to be recognised as simpler proteins. 



There is no doubt, however, that amino-acids also exist in 

 the ripening seeds, for Wassilieff** has identified, in unripe 

 seeds of Lupinus, arginin, histidin, phenylalanin, valin ; 

 and Schulzeft found, in addition to the above, tyrosin and 

 lysih in unripe seeds of Pisiim sativum, but these amino- 

 acids were found only in very small amounts. It is most 

 probable that they are the result of very slow hydrolysis of 

 the proteins in the seeds, by the ferments present. 



Accompanying those essential cleavage-products in the 

 plant-sap, there occur the cleavage-products of other sub- 

 stances set free in the metabolism, such as cholin, betain, 

 trigonellin, vernin, allantoin, purins, nucleins, etc. These 

 are also conveyed to the ripening seed, and are deposited 

 there, with the protein. They are estimated in the analyses 

 with the nonprotein-nitrogen compounds ; and, as far as we 

 know, are unsuitable material for the protein-synthesis. 



As the seeds ripen and the total nitrogen-content increases, 

 there occurs a relative change in the distribution of the 

 nitrogen, as designated by the terms protein- and nonprotein- 

 nitrogen respectively. 



In order to interpret this change, the following are 

 selected from a series of experiments carried out at the be- 

 ginning of 1909, on the ripening of seeds. 



♦ Journ. prak. Chem. B. 27, 358; 32, 449. 



t Zeit. f. Hiol. B. xii. 



X Landw. Versuchs. B.4', 453. 



§ Versuchs-Stat. 1902, 1903. 



IT Ber. d. Bot. Ges. 23. 



** Journ. exp. Landwirtsehaft. (riiss. ) 1904, S.34. 

 +t Zeit. pliysiol. Chem. 65, 1910, S.431. 



