384 Prof. J. R. Green. On the 



disappeared. The amount of material extracted by the ether is about 

 the same for the first three days, when it gradually and regularly 

 diminishes, and at the same time gradually changes its character, be- 

 coming much more acid, and containing increasing quantities of water. 

 The endosperm altogether is much more watery at that stage, a certain 

 amount coming away with the ether, and having to be separated by 

 decantation before evaporating the latter. At the conclusion of the 

 period, a considerable amount of acid is left in the endosperm, which is 

 soluble in water and in ether. The quantities of this acid and of the 

 sugar increase up to the fourth day, and then remain fairly constant, 

 a slight further increase only being noticed in the acid. This is to 

 be accounted for by the rapid development of the plant at about that 

 time, the material leaving the endosperm being that at whose expense 

 this growth takes place. 



No glycerine could be detected in the endosperms throughout. 



In the second set of experiments, in which the endosperms were 

 separated from the embryos, no quantitative estimation was made 

 of the sugar, as its formation coincidently with the disappearance of 

 the oil had been noted continually. 



Taking the endosperms alone as shown in the table (p. 385), they 

 bear out the hypothesis based upon the examination of the whole plant. 

 The acid which was dialysable increased in the endosperms up to the 

 fourth day, and then gradually diminished, pointing to an absorption 

 taking place at a rather faster rate than its formation. Taking the 

 whole plant, the acid increased slightly after this time, showing that 

 it was not used in the growing-points quite so rapidly as it was 

 absorbed, but still was undergoing metamorphosis there. 



The fact that at the close of the period during which the endo- 

 sperm supplies nutriment to the embryo only sugar and dialysable 

 acid are present in its cells, besides a little proteid matter, seems a 

 fair indication that these are the bodies into which the reserve 

 material of the oil is transformed for absorption. 



The reserve materials of the resting endosperm are thus found to 

 be all replaced by derivatives which are capable of absorption by 

 dialysis. 



There is still left a very important question to discuss. Starting 

 with oil and proteids in the resting seed, we find crystallisable acid, 

 sugar, and asparagin passing into the young embryo, and we note 

 intermediate bodies in the shape of the various fatty acids present in 

 castor oil, and of peptone. We find, further, that glycerine which 

 can be liberated from the oil by the ferment, and by laboratory 

 methods, escapes notice however closely it is looked for. What are 

 the probable decompositions that take place, and how can these 

 explain the various products found ? . 



We have clearly first the splitting of the oil into the fatty acids 



