ORIGIN FROM CARBOHYDRATES 73 



he also found that a neutral oil would not enter the cell unless 

 there were present a minimum of 10 per cent, of free fatty 

 acid. It was therefore concluded that the free acid formed a 

 soap which emulsified the fat, in which condition it could move 

 from cell to cell, a conclusion which Schmidt supported by 

 his inability to detect either sugar or starch in the endosperm 

 of germinating fat-containing seeds. Rhine * has repeated 

 Schmidt's work and disagrees with his observations and con- 

 clusions. Rhine found that the rise of oils in the intercellular 

 space system was not dependent on the presence of free acid, 

 and that neutral fats do enter the cell from the intercellular 

 spaces, but this is dependent, not on the presence of free acid, 

 but on the water deficiency of the cell wall ; if the cell wall is 

 not allowed to lose water, which, from the experimental pro- 

 cedure, is likely to happen, there is no intake of fat. The 

 presence of relatively large quantities of sugar was established 

 in the endosperm of germinating seeds of the castor oil plant, 

 hemp and flax ; Schmidt found none. Rhine also points out 

 that the soap formation would appear to be improbable in 

 view of the pH values which occur. The formation of a soap 

 is dependent on a neutral or alkaline medium, an acid reaction 

 is inhibitive ; in the plants examined, the reaction was always 

 on the acid side ; in most tissues the pU was 6-2, the highest 

 value observed being 6-8. 



As may be read in the chapter on Respiration, the respi- 

 ratory ratios differ in accordance with the material consumed ; 

 from his comparison of these ratios in the hypocotyls of seed- 

 lings of fat-containing seeds and of starchy seeds, Rhine con- 

 cludes that the material respired by the former could not be 

 fat. Thus the general conclusion is reached that in normal 

 conditions fats are not translocated as such, and that the fat 

 contained in a seed undergoes hydrolysis and is converted 

 into sugar before transport takes place. 



Le Clerc du Sablon, Ivanow, Miller and others have thrown 

 much light on the hydrolysis of fats in their studies on the 

 germination of various fat-containing fruits and seeds. Lipase 



* Rhine : " Bot. Gaz.," 1926, 82, 154. 



