ON THE FORMATION OF ARGININ IN CONIFEROUS PLANTS. 47 



Plate VI. shows the influence of light upon the change 

 of nitrogenous compounds. Shoots were at first exposed to the 

 full day-light for 19 days, then a portion was kept in the dark 

 for 9 day, while the other portion was still exposed to the day- 

 light. The black lines refer to shoots exposed to the full day- 

 light. The red lines refer to shoots afterwards kept in the dark 

 for 9 days. 



The chief results obtained from the above four experiments 

 are : — 



1) . Arginin accumulates in a large quantity, in the dark as 

 well as in full day-light, in the first stage of germination but 

 disappears quickly when the shoots are further exposed to day- 

 light, most probably being directly used for the regeneration of 

 proteids. It, however, increases gradually when the shoots are 

 kept still further in the dark. 



2) . The formation and transformation of arginin in conifer- 

 ous plants are far greater and quicker than those of asparagine. 



3) . The addition of mineral nutriments accelerates the 

 transformation of arginin. 



4) . Asparagine is also present in a tolerably large quantity 

 in the shoots of coniferous plants. It must have also an import- 

 ant function. 



Although we have not been able to prove experimentally the 

 transformation of other amido-compounds into arginin, yet we 

 can deduce its probability from the following facts : — 



a) In the shoots, we find sometimes so much arginin that 

 we can not regard it as merely the primary decomposition 

 product. Thus I found in the shoots of Cryptomeria japonica 

 about 21% of the total nitrogen in the form of organic bases ; 

 while, when the proteids of the seed are treated with dilute or 

 strong hydrochloric acid, the nitrogen of the organic bases 

 amounts to only of the whole. Therefore if arginin came 



only from the hydrolytic decomposition of proteids, then we 

 should never find more than of the total nitrogen in the 



shoots. Further, I found that the proteids prepared from the 

 shoots of Pinus Thunbergii, have also the same chemical 

 nature, and produce, by the action of hydrochloric acid, almost 

 the same quantity of organic bases as those of the seeds. This 

 fact may hold good also in the shoots of other Coniferae. Now 



