176 



PHYSIOLOGY OF NUTRITION 



During the germination of proteinaceous seeds also (such as those of the 

 Leguminosse^), the decrease in dry weight is due to loss of carbon, hydrogen 

 and oxygen. Protein decomposition occurs at the same time, with the formation 

 of asparagin and amino acids. Glucose is formed from the non-nitrogenous 

 substances, and the cellulose content increases. The table given below shows 

 analyses of seeds and seedlings of Lupinus luteus, the quantities being percent- 

 ages of the total dry weight of the seeds. Sulphates also appear, as a by- 



ToTAL Dry 

 Weight 



Proteins 



Aspara- 

 gin 



Other Nitro- 

 genous Sub- 

 stances 



Glu- 

 cose 



Cellu- 

 lose 



Seeds 



Seedlings... .'. 



Gain or loss during 

 germination 



100.00 

 81.70 



-18.30 



4S-07 

 II .06 



-34.01 



0.00 

 18.22 



-1-18.22 



11.66 

 23-97 



-I-12.31 



0.00 

 2.10 



-t-2.IO 



3-24 



6.47 

 +3.23 



product of protein decomposition in the germination of proteinaceous seeds; 

 lupine seeds with an equivalent sulphuric acid content of 0.385 g. were germi- 

 nated and showed a corresponding content of 0.610 g. when seven days old, and 

 one of 1.323 g. when fifteen days old. 



In the germination of fatty seeds (such as those of Hehanthus, Cucurbita, 

 Ricinus, etc. 2) the loss in dry weight occurs almost entirely through loss of car- 

 bon and hydrogen, while the amount of oxygen actually increases through 

 absorption. The stored fats decrease during this process and are replaced by 

 starch, which shows how the absorption of oxygen is to be interpreted. Fats 

 are much poorer in oxygen than starch, and the formation of starch from fats is 

 therefore possible only with addition of oxygen. The hydrolysis of fat results 

 in an increase in the fatty acid content of the seeds during germination. ' The 

 following experiment may serve as an illustration of this. Twenty grams of 

 poppy seeds contained 8.915 g. of fat and 0.975 g- of free fatty adds. After 

 germination for four days 3.77 g. of free fatty acids were present, and only 3.90 

 g. of fat. Glycerine, however, was not found in the seedlings. 



The following table illustrates the changes that occur during the germination 

 of sunflower seeds. The numbers represent percentages, on the basis of the 

 original total dry weight of the seeds.^ 



' Schulze. E., and UmUuft, W. Untersuchungen iiber einige chemische Vorginge bei der Keimung der 

 gelben Lupine. Landw. Jahrb. s: 821-868. 1876. 



2 Laskovsky, Die Keimung der Kfirbissamen in chemischer Beziehung. Moscow. 1874 ' 

 ' Frankfurt, 1894. [See note s, p. 171.] 



