1920] 



JONES— MAPLE SEEDS 



H5 



Accompanying after-ripening there is a considerable increase 

 in free reducing sugars. Free reducing sugar reaches a maximum 

 at the beginning of germination, and then diminishes as germina- 

 tion progresses. There is, no doubt, a considerable amount of 

 sugar used up in respiration during the long after-ripening period 

 in the germinator even at temperatures as low as 5 C. Whether 

 the appearance of considerable amounts of free reducing sugars is 

 merely correlated with after-ripening or is essential for the com- 

 pletion of after-ripening is not known. The formation of free 

 sugars may be favored by cool uniform temperatures and high 

 state of hydration of the embryo. 



TABLE IX 



Stage 



Kjeldahl nitrogen as percentage of total dry weight in 



F, 



Fa 



F, 



Dormant 



O.03 

 O.03 



O.03 



O.03 



? 



1.58 

 1.48 



1.63 



237 

 315 



5.56 

 S-SQ 



After-ripened 



Beginning germination, radicle 

 about 1 cm 



K. 2Q 



Seedlings with 2-3 cm. radicle 

 (with integuments) 



4. 73 



Seedlings with 5-6 cm. radicle 

 (integuments shed) 



~ 4 %J 



4 04 





t yr 



Seedlings with radicles 2-3 cm. long show an increase in poly- 

 saccharides, but a decrease in free reducing and sucrose or sucrose- 

 like sugars. Correlated with this increase in polysaccharides is a 

 considerable reduction in percentage of fat. The percentage of 

 ether extract drops from about 17 per cent in the dormant and 

 after-ripened seeds to slightly less than 14 per cent in the seedling 

 with a radicle 2-3 cm. long. The fats in the early stages of germina- 

 tion are probably converted into sugar or sugar-like materials, as 

 found in the haw by Eckerson (ii), in the sunflower by 

 Miller (19), and in the castor bean by Deleano (9). 



With germination there is the usual increase of the more 

 soluble nitrogen of F 2 . There is no significant change in relative 

 nitrogen value of the dormant and after-ripened seeds. Table IX 

 shows the relative amounts of nitrogen in the various fractions 

 at different stages of the seeds and seedlings. 



