FATS, WAXES, AND LIPOIDS 153 



carbohydrates. Sugars are commonly spoken of as being "fat- 

 tening" and during the sugar season in cane-growing regions, 

 the Negroes who work in the cane fields get noticeably fatter. 

 All this tends to show a connection between the fats and the car- 

 bohydrates, but more definite experimental evidence is at hand. 

 Schmidt (1891), Le Clerc du Sablon (1893-1897), Ivanov (1911- 

 1912), and others have shown with castor beans, peony, almond, 

 walnut, rape, and other fatty seeds, that the fat makes its ap- 

 pearance in the storage organ as the plant approaches maturity, 

 and that this appearance of the fat is accompanied by a decrease 

 in the carbohydrates present. For the almond the following 

 figures (from Le Clerc du Sablon) are given, which are typical 

 of other plants as well : 



Glucose, sucrose, and starch appear to be the foods commonly 

 used for this transformation, the latter being first hydrolyzed to 

 monosaccharides. In many evergreens similar changes from car- 

 bohydrates to fats are observed during cold weather, the carbo- 

 hydrates reappearing on the approach of warm weather. 



How are the carbohydrates transformed into the fatty acid 

 and the glycerol? If we compare the formulae of a hexose and 

 glycerol, it is easy to see how two molecules of glycerol could be 

 derived from one of glucose. During the World War methods of 

 producing glycerol from sugar by means of fermentation were 

 developed to a high degree of perfection by the Central Powers. 

 The more difficult problem is to form the organic acids from sugar. 

 If a hexose is compared with a fatty acid containing six carbon 

 atoms, such as caproic acid, it would seem not impossible to pro- 

 duce one from the other. Two changes only would be needed. 



HHHHH O HHHHH O 



H— C— C— C— C— C— C H— C— C— C— C— C— C 



HHHHH OH OH OH OH OH OH H 



caproic acid a hexose 



