80 Prof. J. Reynolds Green and Mr. H. Jackson. [Mar. 22, 



the protoplasm in the endosperm for the nutrition of the outlying embryo 

 as its growth continues. Apart from such secretion the endosperm contains 

 no carbohydrate material, while the latter seems to be essential for the 

 maintenance of merismatic tissue. The fact that this carbohydrate substance 

 is cane-sugar coincides with the observation of Brown and Morris* that 

 cane-sugar is always present in the growing embryo of the barley-grain. 

 It appears to be a form of carbohydrate very suitable for serving as a 

 temporary reserve material, more easily utilisable than starch, and therefore 

 formed where the deposit of the reserve will be of very short duration, 

 as in the case of the embryo, and in that of the foliage-leaf, where Brown 

 and Morris found it at a very early period of the photosynthetic construction. 

 Indeed, from the results of analyses of the mixed sugars then present they 

 suggested that it might even be the first sugar formed.t 



It may again be noted that in the case of Bicinus its formation is 

 accompanied or speedily followed by the secretion of invertase. The enzyme 

 is not present in the resting seeds, but develops in the endosperms after 

 exposure to a temperature of 25° C. in moist earth or sawdust for 48 hours 

 or less, though germinative changes are not visible so soon in the external 

 appearance of the seeds. The amount of the enzyme increases continuously 

 all the time of germination, and the invert sugar increases coincidently. 

 The protoplasm appears to keep up a secretion of cane-sugar and the 

 invertase seems to keep working on the latter, so as to supply invert 

 sugar at once to the protoplasm of the cells and to the young absorbing 

 embryo. 



It will be seen from what has been said that we do not associate the 

 formation of this carbohydrate material during the germination directly 

 with the diminution in quantity of the oil which is taking place at the 

 same time. Our experiments lend no support to the views of Sachs that 

 the oil was directly transformed with either sugar or starch. The two 

 processes are features of a new metabolism set up in the cells as germination 

 becomes established. To this point we shall return later. 



The Acids of the Germinating Seeds. 



The question of the nature of the acid to which the reaction of the 

 germinating seed is due remains to be dealt with. Evidence of acidity can 



* Brown and Morris, "Researches on the Germination of some of the Graminea?, :) 

 ' Journ. Chem. Soc.,' vol. 57 (1890), p. 518. 



t Brown and Morris, "A Contribution to the Chemistry and Physiology of Foliage 

 Leaves," ' Journ. Chem. Soe., ! May, 1893, p. 673. 



