378 Prof. J. R. Green. On the 



Thus the germinating seeds are seen to contain at least two ferments, 

 both working towards the utilisation of the reserve materials in the nutri- 

 tion of the embryo. 



The glyceride ferment is capable only of producing fatty acid and 

 glycerine from the oil. The changes cannot, however, end with this 

 decomposition. Fleury had noticed in 1865* that there was free acid 

 formed during germination. Miintz had pointed out tliat the reaction 

 of the embryo was strongly acid, and that at no stage in the germina- 

 tion could he detect glycerine in any of the tissues.f Again, sugar is 

 present in the germinating endosperms in abundance. 



Before making experiments on the possible decompositions of the 

 bodies resulting from the action of the ferments, it seemed advisable 

 to examine more carefully the contents of the endosperm. Some 

 seeds were germinated till the endosperms were on the point of sepa- 

 rating from the cotyledons ; they were then removed, and the endo- 

 sperms ground up in a mortar with distilled water. This solution 

 was strongly acid. It filtered nearly clear, but was a little opales- 

 cent, which appearance was found under the microscope to be due to 

 very minute drops of oil or fatty acid. The solution was then 

 dialysed with distilled water for two days, when the dialysate was 

 found to be acid in reaction. The power of dialysis of the free fatty 

 acids was presumably small, they being extremely greasy liquids, very 

 much like the oil itself. Careful experiments showed that they had 

 no power of dialysis, or at most an extremely feeble one, whether 

 tested as they were or made up into an emulsion. After two days' 

 exposure in a dialyser, the outside liquid had the merest trace of 

 acidity. The experiment noted above,J when the digestion was 

 carried out in a dialyser, also negatives the theory of their being able 

 to pass a membrane, for, though glycerine passed out during the 

 experiment, the action of the dialysate remained neutral. As, then, 

 ricinoleic acid will not dialyse, there was evidently another acid in 

 the germinating endosperm. The dialysate of its extract was next 

 evaporated to dryness on a water-bath, and the residue extracted with 

 ether. A certain amount of insoluble matter was left, and the extract 

 therefore filtered. On slowly evaporating the ether, it deposited a 

 crystalline residue, which was freely soluble in water with a resulting 

 acid reaction. 



An extract of the cotyledons gave exactly similar results. This 

 new acid was really the cause of the acid reaction of the whole of the 

 tissues of the young plant, already shown to exist by several of the 

 writers already quoted. 



The extracts themselves, of both endosperms and cotyledons, 



* Op. dt. 

 f Op. cit. 

 I P. 375. 



