ORIGIN FROM CARBOHYDRATES 71 



although obscure, between protein and fat. Thus Stark * 

 found that the oil and protein content of the soy bean are 

 correlated, in that cultural conditions which influence the one 

 also influence the other in the opposite direction ; manuring 

 with lime, phosphate and organic substances results in an 

 increase of protein and a decrease in fat ; potash, on the other 

 hand, has an opposite effect. 



Origin from Carbohydrates. — The weight of evidence 

 favours the view that in the carbohydrates is to be found the 

 origin of fats in most instances. 



The conversion of carbohydrate to fat in plants, or parts 

 of plants, exposed to a low temperature ; the development of 

 fats in immature seed separated from the parent plant ; and 

 the fattening of animals on a carbohydrate diet, indicate the 

 close physiological connection between the two classes of 

 compounds. 



The evidence given by the facts relating to the development 

 of fats in storage organs such as the seed and structures of 

 vegetative propagation and to the changes which take place 

 in the germination of a fat-containing seed, may here be 

 given. 



Fat makes its appearance in the storage organ as that mem- 

 ber approaches maturity. There can be but little doubt that 

 it is formed in situ from materials in the immediate neighbour- 

 hood, a fact which is emphasized by many observations on the 

 development of fats in seeds isolated from the plant whilst in 

 an immature condition and originally containing little or no 

 fat. 



Quantitive results are not wanting. Numerous obser- 

 vations, amongst which those of Schmidt, Le Clerc du Sablon, 

 de Luca, Funaro, and Ivanow may be mentioned, show that 

 in the maturation of the seed, the increase in the amount of 

 fat and the decrease in the amount of carbohydrate are con- 

 current. This is illustrated in the accompanying tables 

 representing the results of two experiments by Le Clerc du 

 Sablon : — 



* Stark : " Journ. Amer. Soc. Agron.," 1924, 16, 636. 



