38 FATS, OILS, AND WAXES 



no change in the iodine value. The observations of Schmidt, 

 however, have been corroborated by Miller, who found that in 

 Helianthus annuus the iodine value decreased from 1 36*2 

 for the seed to 67-4 for a seedling with the plumule just 

 elongating. 



Further corroboration is given by Ivanow* who, for his 

 study on the transformation of fats during germination, selected 

 flax, hemp, rape, and poppy seeds, since each is characterized 

 by the possession of fats rich in acids of a specific series. 

 Thus the oil of hemp seed is rich in acids of the unsaturated 

 linolenic series, whilst poppy-seed oil is rich in acids of the 

 saturated fatty acid series. 



By ascertaining the iodine and other values of the fats of 

 these seeds at different periods of germination, it was found 

 that the acids disappeared in the sequence linolenic, linolic, 

 oleic, and, finally, palmitic; in. other words, the acids were 

 consumed at a rate inversely proportional to their degree of 

 saturation. 



Ivanow considers that the fall in the iodine value of the 

 fats is due rather to the rapidity with which the more un- 

 saturated fatty acids are used up in the formation of carbo- 

 hydrates rather than to their oxidation. He further found 

 that the saturated fatty acids not uncommonly exist in a free 

 state whilst the unsaturated acids occur in the form of 

 glycerides. 



Von Fiirth also found that during germination the acetyl 

 value decreased from 87*5 in the resting seed to 50 5 in the 

 young seedling, from which he concluded that the normal fatty 

 acid does not change into hydroxy fatty acid. Also, he could 

 find no proof of the fatty acid breaking down into simpler 

 substances as indicated by the molecular weight remaining 

 practically constant. 



This hydrolysis is the first action, but it is not the final one 

 since carbohydrates quickly appear during the germination of 

 such seeds. Since the days of de Saussure, who was the first 

 to draw attention to this phenomenon, much evidence relative 

 to this carbohydrate formation has accumulated. 



In the case of Ricinus le Clerc du Sablon found that the 

 resting seed contained 69 per cent of oil and 4 per cent of 

 sugar, but in a seedling 1 1 cm. high the oil had fallen to 1 1 per 



* Ivanow: " Jahrb. wiss. Bot.," 1912, 50, 375. 



