HOW PLANTS GROW PR031 THE SEED. 
21 
into sugar, and dissolved in the water which is absorbed from the ground ; the coty¬ 
ledon imbibes this, and sends it into the radicle, r, to make the root, and into the 
plumule, p, enabling it to develop the set of leaves, 
wrapped up one within another, of which it consists, 
and expand them one after another in the air. Fig. 
47 shows a sprouting grain, sending down its first 
root, and sending up the plumule still rolled together. 
Fig. 48 is the same, more advanced, having made a 
whole cluster of roots, and unfolded two or three 
leaves. Nourished abundantly as it is, both by the 
maternal stock in the grain, and by what these roots 
and leaves obtain and prepare from the soil and the 
air, the young corn gets a good start, is ready to avail 
itself of the summer’s heat, to complete its vegeta¬ 
tion, to blossom, and to make and lay up the great 
amount of nourishment which we gather in the crop. 
46. The Onion. The cotyledon in Indian Corn, and 
most other plants which have only one, stays under 
ground. In the Onion it comes up and makes the 
first leaf, — a slender, thread-shaped one, — and in¬ 
deed it carries up the light seed on its summit. In 
Indian Corn, all the early joints of stem remain so 
short as not to be seen ; although later it makes long 
joints, carrying up the upper leaves to some distance 
from one another. In the Onion, on the contrary, the 
stem never lengthens at all, but remains as a thin 
plate, broader than it is long, with the roots springing from one side of it and the 
sheathing bases of the leaves covering it on the other. 
47. Number of Cotyledons or Seed-Leaves. Indian Corn (Fig. 46) and all such 
kinds of grain-plants, the Onion, Lilies, and the like, have only one seed-leaf or 
cotyledon to their embryo; therefore they are called Monocotyledonous Plants, 
and the embryo is called monocotyledonous , — a long word, meaning “with one 
cotyledon.” 
48. The embryo of the Morning-Glory (Fig. 19), of the Maple (Fig. 27), 
Bean (Fig. 32-34), Almond, Peach, and Cherry (Fig. 36-38), Oak (Fig. 40), 
