468 THE SEED AND ITS GERMINATION. 



two hours, all the starch will be found to have been converted 

 into and dissolved as soluble carbohydrates, sugar, and dextrin. 

 The change in this case is attributed to the ferment, diastase, 

 one part of which, it is claimed, can convert two thousand 

 parts of starch into sugar. It will be noted that in the pro- 

 cess above described the temperature (68 C.) is much higher 

 than that at which ordinary germination proceeds. 



Dubrunfaut 1 has given the name maltin to a ferment far more 

 active than diastase, found in ah 1 germinating cereals. This is 

 able to convert into a soluble state from one hundred thousand 

 to two hundred thousand times its weight of starch. It forms 

 with tannic acid an insoluble compound which retains its power 

 for a long time. In good barley meal there is one per cent of 

 maltin. 



1220. The oil in oily seeds is in germination carried through 

 a long series of changes. It is first transformed into starch, and 

 then follows the same course as starch, alread}' described. 2 



1221. Van Tieghein has shown that oleaginous albumen, rich 

 in aleuron, has an activity of its own which enables it to digest 

 itself, so to speak, and thus become at once fit for the embryo 

 to use ; on the other hand starchy albumen and cellulosic albu- 

 men must be first acted on by the embryo, and thus become 

 dissolved and ready for use. 8 



1222. The changes which take place in a germinating seed 

 are accompanied by direct or indirect oxidation of a portion of 

 the nutrient matters, a release of energy, and an evolution of 

 carbonic acid. 4 The amount of CO 2 given off by germinating 

 seeds and the rise of temperature serve as measures of the 

 process of oxidation. 



1223. It is not proved that germination can be hastened by 

 chemical means. Experiments with dilute chlorine water seem 

 to show that the time can be somewhat lessened, but the results 

 are discordant. 6 



1224. It has been asserted recently that the presence of mi- 

 crobes, the minute organisms to which putrefaction is due, is 



1 Comptes Rendus, Ixvi., p. 274. 



a Peters, Vereuchs-Stationen, iii., 1861, p. 1 ; Miintz, Ann. de Chimie et 

 de Physique, ser. 4, tome xxii. p. 472. 



8 Ann. des Sc. iiat., ser. 6, tome iv., 1877, p. 189. 



* For the changes in the horny endosperm of the date palm see Sachs, 

 Botanische Zeitung, 1862, p. 241. 



6 See M. Carey Lea, American Journal of Science, xxvii., 1864, p. 373, 

 and xliii., 1867, p. 197. 



