48 



FATS, OILS, AND WAXES 



obtained from the leaves of CJieyiopodium vulvaria, from the 

 blossoms of Crataegus Oxyacantha, from species of Pyrus, and 

 from the seeds of Fagus (see p. 266). 



Lecithins form compounds with sugar, and it is stated that 

 all lecithins of a vegetable origin are in combination with carbo- 

 hydrates ; galactose, glucose and pectose having been identified. 

 The amount of this combined sugar varies pretty considerably ; 

 it may be as high as 16 per cent according to Winterstein 

 and Hiestand.* 



Formation of Lecithin. 



The following table, due to Green and Jackson,f shows the 

 relation between the lecithin, fatty acid, and oil of the endo- 

 sperm of Ricinus, expressed in per cent of weight of the seeds 

 at different stages in their germination : — 



From this it appears that lecithin is formed during germination ; 

 although there is, during the early stages of germination, a 

 diminution in the quantity present. It was found when once 

 the maximum was reached that this amount remained constant 

 until the whole of the endosperm was used up. 



The products of the decomposition of lecithin, viz. a fatty 

 acid, glycerophosphoric acid, and choline, have been detected by 

 Green and Jackson in the endosperm of germinating seeds of 

 Ricinus, and they suppose that the action is reversible, so that 

 the lecithin is formed by the combination of the products of 

 decomposition of the oil and protein reserves of the seeds. 

 Thus the oil provides the fatty acid and the glycerol, of which 

 the latter combines with phosphorus, obtained from the 

 aleurone grains, to form glycerophosphoric acid. The choline 



* Winterstein and Hiestand : loc. cit. 

 t Green and Jackson : loc. cit. 



