468 Changes in the Seed accompanying Germination: [Dec. 16, 



In the resting seed the ferment exists in the form of a zymogen, as 

 is the case with those of the stomach and other digestive organs. 

 This is, however, very readily converted into the active ferment by 

 contact with dilute acids. The point was somewhat difficult of proof, 

 but was ascertained by a modification of the method adopted by 

 Langley and Edkins* in their work on the condition of the ferment in 

 the gastric glands. From this paper it appears that while both 

 alkalis and C0 2 destroy both the ferment and the zymogen, the latter 

 is much more easily affected by C0 2 than the former. I found this 

 to be the case with the extracts of the seeds. After a stream of C0 2 

 had been passed through them, treatment with acid failed to make 

 them active, though the acid soon developed ferment-power in 

 extracts not treated with the gas. The reaction of the resting seeds 

 was neutral. 



The proteids existing in the seeds of Lujoinus have been ascertained 

 by Vinesf to consist of hemialbumose and globulin. I prepared from 

 a quantity of the resting seeds a considerable bulk of these by the 

 methods Vines describes, and submitted them in a state of fair purity 

 to the action of the ferment. The outcome of a long series of experi- 

 ments so carried out was that the proteids of the seeds were changed 

 by the ferment in much the same way as fibrin. There was soon a 

 quantity of parapeptone formed, which was soluble readily in weak 

 acids or alkalis. This was followed or accompanied by the appear- 

 ance of peptone, and later, leucin and asparagin were formed. The 

 latter bodies were obtained in -some quantity by the method described 

 by v. Gorup-BesanezJ for the separation of leucin from other bodies 

 in the fluids in which it is found. 



This course of digestion of the seed proteids was confirmed by 

 examination of the seeds at different stages in their natural germina- 

 tion. In those which were just starting, parapeptone in quantity was 

 present in the germinating cotyledons; a little later abundance of 

 peptone was found. In no case was peptone found in the radicles, but 

 from these plenty of asparagin was easily obtainable. 



Besides the biuret test for the peptone a more delicate one was 

 generally used, which has been described by many writers. It 

 consists in freeing the solution from all other proteids by boiling with 

 freshly prepared ferric acetate and then adding to it acetic acid and 

 phosphotungstate of soda. Peptone is then precipitated. 



The conclusions which seem to follow from the whole course of the 

 experiments are : — 



1. There exists in the seed of the lupin when germinating a proteo- 



* * Journal of Physiology,' toI. 7, p. 371 (1886). 

 t ' Journal of Physiology,' vol. 3, p. 93 (1881). 



X ' Anlcitung zur qualitatiren und quantitativen Zoochemischen Analyse.' 



