COMPARISON OF THE PARTS OF THE SOAKED SEEDS.
_Morning-Glory_. A seed covering. Some albumen. Two cotyledons. A
caulicle.
_Sunflower_. An outer covering.[1] An inner covering. Two cotyledons. A
caulicle.[2]
[Footnote 1: The so-called seed of Sunflower is really a fruit. The outer
covering is the wall of the ovary, the inner the seed-coat. Such closed,
one-seeded fruits are called akenes.]
[Footnote 2: The plumule is sometimes visible in the embryo of the
Sunflower.]
_Bean_. A seed covering. Two cotyledons. A caulicle. A plumule.
_Pea_. The same as the Bean.
They have also learned how the first leaves in the last three differ from
those of the Morning-Glory, being considerably thicker in the Sunflower,
and very much thicker in the Bean and Pea. Why should the Morning-Glory
have this jelly that the others have not? Why do the first leaves of the
Sunflower change so much as the seedling grows? What becomes of their
substance? Why do those of the Bean shrivel and finally drop off? By this
time some bright pupil will have discovered that the baby-plant needs food
and that this is stored around it in the Morning-Glory, and in the leaves
themselves in the others. It is nourished upon this prepared food, until
it has roots and leaves and can make its own living. The food of the
Morning-Glory is called _albumen_; it does not differ from the others in
kind, but only in its manner of storage.
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