16 



FOUNDATIONS OF BOTANY 



the outer coat by cutting it with a knife. From seeds which have 

 been soaked in water at least twenty-four hours peel off the coatings 

 and sketch the kernel. Make a cross-section of one of the soaked 

 seeds which has not been stripped of its coatings, and sketch the sec- 

 tion as seen with the magnifying glass, to show the parts, especially 

 the two cotyledons, lying in close contact and encircling the white, 

 starchy-looking endosperm. 1 



The name endosperm is applied to food stored in parts of the 

 seed other than the embryo. 2 With a mounted needle pick out the 

 little almost spherical mass of endosperm from inside the cotyledons 

 of a seed which has been deprived of 

 its coats, and sketch the embryo, noting 

 how it is curved so as to enclose the 

 endosperm almost completely. 



19, Examination of the- Kernel of In- 

 dian Corn. Soak some grains of large 

 yellow field corn 3 for about three days. 



Sketch an unsoaked kernel, so as to 

 show the grooved side, where the germ 

 lies. Observe how this groove has be- 

 come partially filled up in the soaked 

 kernels. 



Remove the thin, tough skin from 



FIG. 6. Lengthwise Section of 



Grain of Corn. (Magnified 



about three times.) 



tion of food from it ; r, 

 primary root. 



, yellow, oily part of endosperm-, one of the latter, and notice its transpar- 

 w, white, starchy part of en- ency. This skin the bran of unsifted 

 dosperm ; p, plumule ; *, the CQrn meal _ doeg not exact l y correspond 

 shield (cotyledon), in contact . 



with the endosperm f or absorp- to the testa and inner coat of ordinary 

 the seeds, since the kernel of corn, like all 

 other grains (and like the seed of the 

 four-o'clock), represents not merely the seed, but also the se,ed-vessel 

 in which it was formed and grew, and is therefore a fruit. / 



1 Buckwheat furnishes another excellent study in seeds with endosperm. 

 Like that of the four-o'clock, it is, strictly speaking, a fruit ; so also is a grain 

 of corn. 



2 In the squash seed the green layer which covered the embryo represents 

 the remains of the endosperm. 



3 The varieties with long, flat kernels, raised in the Middle and Southern 

 States under the name of " dent corn," are the best. 



