444 



PLANT PHYSIOLOGY 



As has been shown by S. Ivanov, the character of the oil, also, 

 changes during ripening. In the beginning of this process, 

 saturated fatty acids prevail; later, the unsaturated acids 

 increase in proportion until they become more abundant, and 

 toward the end of ripening, the seeds are filled with neutral fat 



8-VI 12-VII 15-Vll 19-Vll 22-VII 26-VII 29-vil 3-Vlll 

 Fig. 138. — Course of the accumulation of substances during the ripening of 



wheat grain. 



of mostly unsaturated acids. He presents the following scheme, 

 based on these data, for the formation of fats in ripening seeds: 



carbohydrates C 



glycorin- 



"\ 



saturated fatty acids — > unsaturated fatty acids ^ 



oil 



From Thatcher's data, it follows that ash is accumulated 

 (luring ripening. As it proceeds, the quantitative relations 



