STORAGE OF FOOD IN THE SEED 
13 
15. Examination of the Four-o’clock Seed. — Examine the external 
surface of a seed! of the four-o’clock. and try the hardness of the 
Fic. 4. Germinating Peas, growing in Water, 
one deprived of its Cotyledons. 
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 section, 
as seen with the mag- 
nifying 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. 
16. Examination of the Kernel of Indian 
Corn. — Soak some grains of large yellow 
field corn * for about three days. 
1 Strictly speaking, a fruit. 
2 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. 
Fie. 5. 
1 pa8 
Seeds with En- 
dosperm, Longitudinal 
Sections. 
I, asparagus (magnified). 
II, poppy (magnified). 
3 Reserve food derived from the part of the ovule (nucellus) just outside 
of the embryo sac (Fig. 124) is called perisperm. 
4 The varieties with long, flat kernels, raised in the Middle and Southern 
States under the name of ‘“‘ dent corn,’’ are the best. 
