NATURE OF PLANTS 



135 



is treated with the eosin solution referred to above it will be 

 seen that at first the water enters by way of the little stalk just 

 as did the food that was supplied to the growing grain. In 

 this way water is supplied directly to the root of the embryo 

 which lies near the stalk as shown in Fig. 86, B. If two seeds 

 are soaked until soft and then sectioned so as to cut one across 

 and the other longitudinally through the embryo it will be seen 



Fig. 86. Grain and seedling of corn: A, two views of a grain — s, point of 

 attachment of style; p, stalk attaching the grain to cob; emb, location of 

 embryo. B, longitudinal section of a grain. The embryo consists of a 

 plumule, pi, root, r, and scutellum, sc. en, endosperm. C, cross-section of 

 a grain showing endosperm, en, surrounding the embryo, emh. D, diagram 

 of the outer cells of the scutellum, showing the elongated cells that bring 

 about a solution and absorption of the foods stored in the endosperm. E-G, 

 stages in the growth of the seedling. 



that the endosperm forms the larger part of the grain and that 

 the embryo is relatively small, consisting of a stem and root, a 

 plumule of several closely wound leaves, and a shield-like organ, 

 the scutellum (Fig. 86, B, C). The entire embryo may easily be 

 removed from the endosperm with a knife if the seed is thoroughly 

 soaked. Unlike the two preceding examples the corn is a mono- 

 cotyledon and many regard the scutellum as a modified coty- 

 ledon. This organ forms the enzymes which put into soluble 



