58 FATS, OILS, AND WAXES . 



found acceptance ; it was, for instance, supported by Czapek * 

 in his work on the surface tension of the external limiting 

 membrane, and Green and Jackson f considered that lipins 

 exercise considerable influence on the transport of material 

 from cell to cell. On the other hand, further work on the 

 uptake of inorganic salts and dyes by the vegetable cell and 

 on the surface tension of solutions, indicate the imperfections 

 of Overton's theory. It, however, stimulated investigation 

 on the nature of the plasma membrane and, generally, 

 on permeability, a subject which is without our present 

 province. J 



Palladin§ suggested that lipins play a part in respiration 

 in that the more these substances are extracted with organic 

 solvents, the more is respiration depressed as measured by the 

 output of carbon dioxide in the presence of water during 

 definite periods of time. This thesis involves many problems. 

 Thus, if respiration be a matter of enzyme action, then, 

 presumably, there must be some essential connection between 

 lipin and enzyme. There is no doubt that fats are utilized 

 in respiratory processes ; are they, after desaturation, built 

 up into lipins which are then oxidized for the liberation of 

 energy ? The evidence available on these points relates 

 either to the animal or to the chemical laboratory. Vernon, 1| 

 working on animal tissues, found that if the material were 

 extracted with organic solvents, in order to remove the lipins, 

 the oxidase reaction rapidly disappeared, which means that 

 oxidase reaction is somehow dependent on the cell lipins. 



Further, Gallagher ^ isolated from the potato a lipin 

 which in the presence of oxygen acquired the property of 

 immediately oxidizing guaiacum in the presence of oxidase. 

 If this be significant in respiration, it indicates that oxidase 

 plays an essential part in the process, a conclusion which is 



♦ Czapek : " Ueber eine Methode zur direkten Bestimmung der Ober- 

 flachenspannung der Plasmahaut von Pflanzenzellen," Jena, 1912. 



t I.oc. cit. 



X See Stiles : " Permeability." New Phyt. Reprint, No. 13. 1924- 



§ Palladin : " Ber. deut. bot. Gesells.," 1910, 28, 120. Palladin and 

 Stanevitsch : " Biochem. Zeit.," 1910. 26, 351. 



II Vernon : id., 1912, 47, 374 ; 1914, 60, 202. 



*\ Gallagher : " Biochem. Journ.," 1923, 17, 515. 



