. 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.} 
The name endosperm is applied to food stored in parts of the 
seed other than the embryo. 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 * 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 
- Fic. 6.— Lengthwise Section of kernels. 
Grain of Corn. (Magnified 
about three times.) 
Remove the thin, tough skin from 
- y,yellow, oily part of endosperm; °° of the latter, and notice its transpar- 
w, white, starchy part of en- ency. This skin —the bran of unsifted 
dosperm; p, plumule; s, the ¢orn meal — does not exactly correspond 
shield (cotyledon), in contact : ‘ 
with the endosperm for absorp- 0 the testa and inner coat of ordinary 
tion of food from it; r, 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 seed-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 ayer which covered the embryo represents 
the remains of the endosperm. 
- 8 The varieties with long, flat kernels, raised in the Middle and Southern 
States under the name of ‘dent corn,” are the best. 
