62 GENERAL BOTANY 



that have been softened by lying in water this 

 scutellum can be seen lying on one side of the endo- 

 sperm, and can easily be removed from it. 



If we cut it open right down the middle, we shall 

 find inside a bud of tightly-packed leaves at the upper 

 end, that is the broader rounded end of the grain, 

 and at the lower the pointed tip of the radicle. The 

 axis between the two is attached to the scutellum 

 itself, so that the embryo is enclosed inside the 

 scutellum, and the latter appears to be part of it. 



In grains that have begun to germinate, that part 

 of the endosperm next the scutellum is not hard 

 and yellow as everywhere else, but is soft and 

 white. It is the same sort of change as we found 

 in the Castor, Date-seed and Palmyra-nut and is 

 due to the digestion of the endosperm by some 

 substance secreted from the scutellum. The change 

 in this case is from starch (with which the endo- 

 sperm is packed tight, and which being insoluble 

 in water cannot be absorbed by the plant) into 

 soluble sugar. This is, of course, why the grain be- 

 comes watery and rotten its substance is absorbed 

 by the young plant, just as is the endosperm of the 

 Castor, Date and Palmyra by their cotyledons. In 

 the last case the lower part of the cotyledon sur- 

 rounds the young bud for some time after germi- 

 nation, while the upper part is expanded inside the 

 seed. In the Coco-nut it nearly all remains inside 

 the seed, just as do those of the Pea, and we have 

 something not very different except only in shape 

 from the scutellum of the Maize. We may infer, 

 therefore, that the scutellum is indeed a cotyledon, 



