36 FATS, OILS, AND WAXES 



produced from carbohydrates ; the work of Schmidt,* Le Clerc 

 du Sablon,f and others has shown that as the carbohydrates 

 disappear so fats appear. For example, in the case of the 

 almond the seeds when they begin to ripen are rich in carbo- 

 hydrates and poor in fats, whereas the reverse is true when 

 they are fully matured. The same holds true for the seeds of 

 Ridnus and Ptzonia. The nature of the carbohydrates used up 

 in this process varies in different plants ; thus it is stated that 

 in the case of the olive mannite is the carbohydrate. This 

 statement, due to de Luca, is not accepted by other investiga- 

 tors of the same plant ; according to Funaro the mannite does 

 not appear until after the oil has been formed. 



In the case of Ridnus seeds the oil is formed from glucose, 

 and in Pceonia principally from starch. The facts that fat may 

 be translocated as such, provided it be an emulsion sufficiently 

 fine, or in the form of fatty acid or glycerine, suggest that the 

 fats in seeds have not been formed in situ, but have been con- 

 veyed there. This may be true to a certain extent, but con- 

 sideration of the fact that fat will appear as the carbohydrates 

 disappear in immature seeds removed from the parent plant, 

 together with the facts relating to the formation of fats in vege- 

 tative organs under the influence of cold (p. 3), leads to the 

 conclusion that the substances in question are formed at the 

 expense of carbohydrates. Further, corroborative evidence is 

 afforded by well-ascertained facts relating to similar problems 

 in animals. 



Ivanow, I experimenting with rape seed, has shown that 

 they contain a lipase which may either hydrolyse a fat or may 

 synthesize one from fatty acid and glycerine. Thus, if a 

 glycerine extract of the seed be mixed with oleic acid, fat is 

 synthesized, but, on diluting with water, the fat is split up 

 again. This same author has published important observa- 

 tions on the synthesis of fats in oily seeds mainly from the 

 carbohydrates glucose, sucrose, and starch. These substances 

 are synthesized in the order given, the last two being first 



* Schmidt: "Flora," 1891, 74, 300. 



fLe Clerc du Sablon: " Compt. rend.," 1893, 117, 524; 1894, "9. 6l J 

 1896, 123, 1048; "Rev. Gen. Bot.," 1895, 7, 145; 1897, 9> 3 I 3- 

 J Ivanow: " Ber. deut. hot. Gesells.," 1911, 29, 595. 

 Ibid., "Beith. hot. Centr.," 1912, 28, 159. 



