232 SCIENCE PROGRESS. 



supposition that some of the amido-compounds were con- 

 verted into amides during germination, and this view has 

 been subsequently confirmed. He holds at present that 

 the amido-acids and bases are further decomposed with 

 formation of nitrogenous residues, which unite with anitro- 

 genous compounds to form the amides synthetically. The 

 latter are to be regarded as the material from which the pro- 

 teins of the growing plant are produced, so that they form 

 transitory nitrogenous reserve-substance in etiolated seed- 

 lings. This further chemolysis of the amido-compounds 

 with formation of nitrogenous residues cannot of course be 

 ascribed to enzymolysis ; here again the physiologist must 

 rely on the omnipotent properties of protoplasm for " ex- 

 planation ". 



Thus asparagin can be, to a certain extent, compared 

 with urea, as Boussingault did. Both are partly produced 

 in proteohydrolysis, urea arising from lysatin, 1 while both 

 are produced in major amount through synthetic processes, 

 asparagin (resp. glutamin) from nitrogenous residues of pro- 

 teohydrolysis and anitrogenous compounds, urea through 

 union of ammonia and carbon dioxide to form ammonium 

 carbamate, and subsequent decomposition of this. 



The question of proteinic regeneration forms still a sub- 

 ject of animated discussion, and no definite statement can 

 be made as to the process. The majority of investigators, 

 among which Boussingault, Schulze, C. O. Miiller and 

 Prianischnikow may be mentioned, deny that proteins can 

 be regenerated from amides in the dark, whereas Kinoshita, 

 Hansteen and Zaleski affirm that regeneration occurs. 

 Pfeffer and Borodin ascribe to light an indirect influence, 

 in so far as formation of carbohydrates is concerned, while 

 Miiller asserts that its effect is direct. Also, whereas some 

 observers, as C. O. Miiller, affirm that carbohydrates are 

 not concerned in the regeneration of proteins, light being 

 the determining factor, others, as Pfeffer, Borodin, Kino- 

 shita, Hansteen and Zaleski asseverate that carbohydrates 

 are essential to the process. E. Schulze apparently holds 



1 Lysatin is perhaps a mixture of equal molecules of arginin and lysin 

 (Hedin) ; if this be so, the urea would arise from the arginin. 



