IIOW PLANTS GROW FROM THE SEED. 
13 
31. The root keeps on growing under ground, and sending off more and more 
small branches or rootlets , each one adding something to the amount of absorbing 
surface in contact with the moist soil. The little stem likewise lengthens upwards, 
and the pair of leaves on its summit grow larger. But these soon get their full 
growth; and we do not yet see, perhaps, where more are to come from*. But now 
a little bud, called the Plumule , appears on the top of the stem (Fig. 22), just be¬ 
tween the stalks of the two seed-leaves; it enlarges and unfolds into a leaf; this 
soon is raised upon a new piece of stem, which car¬ 
ries up the leaf, just as the pair of seed-leaves were 
raised by the lengthening of the radicle or first joint 
of stem in the seed. Then another leaf appears on 
the summit of this joint of stem, and is raised upon 
its own joint of stem, and so on. Fig. 23 shows the 
same plant as Fig. 22 (leaving out the root and the 
lower part of the stem), at a later stage; c, c } are the 
seed-leaves ; l is the next leaf, which came from the 
plumule of Fig. 22, now well raised on the' second 
joint of stem ; and l' is the next, still very small and 
just unfolding. And so the plant grows on, the whole 
summer long, producing leaf after leaf, one by one, 
and raising each on its own joint of stem, arising 
from the summit of the next below; — as we see in 
Fig. 4, at the beginning of the chapter, where many joints of stem have grown 
in this way (the first with a pair of leaves, the rest with one apiece), and still 
there are some unfolding ones at the slender young summit. 
32. How the Seedling is nourished at the Beginning. Growth requires food , in plants 
as well as in animals. To grow into a plant, the embryo in a seed must be fed 
with vegetable matter, or with something out of which vegetable matter can be 
made. When a plant has established itself, — that is, has sent down its roots into 
the soil, and spread out some leaves in the air, — it is then able to change mineral 
matter (viz. earth, air, and water) which it takes in, into vegetable matter, and so 
to live and grow independently. But at the beginning, before its organs are 
developed and established in their proper places, the forming plant must be sup¬ 
plied by ready-made vegetable matter, furnished by the mother plant. On this 
supply the embryo germinating from the seed feeds and grows, —just as the new- 
