NATURE OF PLANTS 



121 



a fruit is called a grain and may be compared to a bean pod with 

 a single seed. We can still see upon the grain (Fig. 86, A) 

 at j the position of the style while at p appears the remains of 

 the stem that fastened the sporophyll to the cob. The long 

 threads, often called the silk, that projects from the ears of corn 

 are greatly elongated stigmas for catching the microspores. 

 While the outer parts of the grain of corn are very hard if it 

 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 



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; cmb, 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, cmb. D, dia- 

 gram 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. 



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

 this way water is supplied directly to the stem 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 



