GERMINATION OF OILY SEEDS 



39 



cent and the sugar had risen to 14 per cent. It was further 

 found that the sugar contained in the resting seed has a slight 

 excess of non-reducing sugar, which increased more rapidly 

 than the reducing sugar ; finally, however, the latter variety 

 preponderated. 



Le Clerc du Sablon also found the same relation between 

 oil and sugar to obtain during germination of rape, hemp, 

 poppy, almond, and walnut. 



Similar observations have been made by Green and Jack- 

 son,* who found that in the resting seed of Ricinus the most 

 abundant sugar is sucrose, which gives place to invert sugar in 

 the early stages of germination. Subsequently the sucrose 

 increases in amount, and occurs in quantities greater than the 

 invert sugar ; thus there is reason for supposing that the sucrose 

 is a temporary reserve food. 



The following table which summarizes the changes in the 

 sugar content is taken from Green and Jackson's paper : — 



Miller has found that in the sunflower, Helianthus annuus, 

 the amount of ether extract of the cotyledons diminishes grad- 

 ually from the beginning of germination, the most rapid deple- 

 tion occurring during the period between the first appearance 

 of the seed-leaves above ground and the point of full expansion. 

 Also, the greatest increase in the hypocotyl and roots coincides 

 with the period of maximum depletion from the seed-leaves. 

 With regard to the sugar content. Miller states that the resting 

 embryo contains about 4 per cent of sucrose, during ger- 

 mination there is a decrease, and this is followed by a gradual 

 increase until the seed-leaves begin to unfold. Up to this 

 stage the cotyledons contain only a non-reducing sugar, but as 



* Green and Jackson : " Proc. Roy. Soc, Lond.," B., 1906, 77, 69. 



