CARBOHYDRATES AND FATS 41 



These conclusions are based on the observations that 

 during the germination of the seeds of Arachis the carbo- 

 hydrate increases to 5*6 per cent of the dry weight, whilst in 

 Ricinus the increase is 10 per cent. The glycerine of the fat 

 would be sufficient to forni about 5 per cent of carbohydrate ; 

 this roughly was the amount observed in the case of Arachis, 

 but in Ricinus the amount was about three times as great. 



Maz6 has put forward the suggestion that the transforma- 

 tion of oil into sugar is effected by an enzyme. 



It has already been mentioned that glycerine so far has 

 not been demonstrated in germinating fatty seeds ; this may 

 be owing to its powers of rapid diffusion or to the fact that 

 it is used up in the synthesis of other substances. Thus 

 it has just been mentioned that Maquenne thought that it 

 might be the origin of the sugar in some cases at any rate ; 

 Green originally thought that such was the case in Ricinus, 

 an opinion which he no longer holds. Green and Jackson 

 state that there is reason to suppose that the protoplasm of 

 the endosperm of Ricinus is increased at the expense of the 

 initial reserve food-materials ; subsequently, further carbo- 

 hydrates for the nutrition of the embryo are formed by the 

 activity of this protoplasm : in other words, these authors do 

 not consider that the increase in sugar during germination and 

 the decrease in oil are directly associated ; the disappearance 

 of the latter and the formation of the former are " features of 

 a new metabolism set up in the cells as germination becomes 

 established". Also they express the opinion that the gly- 

 cerine may be used up in the formation of lecithin. 



Le Clerc du Sablon has put forward the idea that there 

 might be present an enzyme which acts on the fat without 

 liberating the glycerine. 



These views are concerned chiefly with the formation of 

 carbohydrates from fats ; a reversal of the process might or 

 might not explain the formation of fats from carbohydrates. 



The whole question is of considerable difficulty and, of 

 course, refuge may be taken in the hypothesis first put for- 

 ward by Nageli that the fats are products of the disintegration 

 of the protoplasm. Thus the carbohydrates might be assimi- 

 lated by the protoplasm which might produce the oil by some 

 catabolic process. 



