GERMINATION OF SEEDS. 



223 



favourable material is thus obtained for quantitative de- 

 terminations, inasmuch as darkness has a considerable 

 retarding influence on the metabolism of nitrogenous com- 

 pounds. Since a description of the methods of analysis 

 adopted in these investigations would be out of place here, 

 the publications concerned with this question are included 

 in the bibliography and will receive no further notice. 



In the subjoined table is a list of some of the plants 

 that have been more systematically examined, with . the 

 nitrogenous compounds resulting from proteohydrolysis 

 during germination that have been isolated and identified, 

 as well as with a notice of the etiolated or chlorophyllous 

 condition of some of the seedlings. It has been found that 

 the effect of insolation is to materially alter the quantity 

 in which these bodies are found in etiolated seedlings ; this 

 alteration is in cases so extreme as to effect a qualitative 

 difference : — 



For the sake of convenience, amido-valerianic acid and 

 phenyl-amido-propionic acid are designated by their shorter 

 names, butalanin and phenylalanin, in this table. 



The occurrence of these compounds is certain, all having 

 been isolated and identified, both qualitatively and quan- 



