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If they were torn away and planted in the ground they would perish. Not all seeds have the food for the embryo stored up in the seed-leaves. If a morning-glory seed be soaked, it will swell up and soften, and the hard outer skin will burst. Inside will be found a tiny embryo with two thin, papery seed-leaves that contain no nourishment to speak of.
Each of these two cells again breaks up into two more, and so the plant grows larger and larger, till by the time it has used up all the food in the seed-leaves, it has sent roots covered with fine hairs downwards into the earth, and a shoot with beginnings of leaves up into the air.
Seeds, germinating in such little moist depressions grow regularly and rapidly, while those on the dryer elevations may be retarded for hours and days, before fully unfurling their seed-leaves. After heavy rains these differences may be observed to increase continually, and in some instances I found that plants were produced only on the wet spots, while the dry places remained perfectly bare.
Usually the young grasses and the seed-leaves of plants have risen up and supply a general green; but this year the coltsfoot bloomed unsupported, studding the dark ground with gold. Now the frogs are busy, and the land lizards come forth. Even these the moucher sometimes captures; for there is nothing so strange but that some one selects it for a pet.
Here we have the true type of an ever-sporting variety. Every year it produces in the same way heirs and atavists. Every plant, if fertilized with its own pollen, gives rise to both types. The parent itself may be tricotylous or dicotylous, or show any amount of multiplication and cleavage in its seed-leaves, but it always gives the entire range among its progeny of the variation.
For I noted it so carefully and lovingly, day by day, the seed-leaves on the mounds in the sheltered places that come so early, the pushing up of the young grass, the succulent dandelion, the coltsfoot on the heavy, thick clods, the trodden chickweed despised at the foot of the gate-post, so common and small, and yet so dear to me.
After the child has studied his beans, let him then study the morning-glory and four-o'clock seeds, which store the food separately from the embryo instead of in its seed-leaves. In every seed there is food enough stored up to give the embryo its first start in life. During the Summer the child can be helped to pass many pleasant hours looking at seed-pods and finding as many kinds as possible.
It is a very simple little seedlet indeed. But after a while its little embryo begins to form and its seed-leaves to develop. When the ovule has developed in this way we call it a seed. It remains attached to the ovary, receiving nourishment from the sap until it is quite ripe. As the seed forms in its little pod, its thick sturdy seed-leaves become larger and fuller.
Imagine the tiny primrose plantlet to be made up of cells filled with active living protoplasm, which drinks in starch and other food from the seed-leaves. In this way each cell will grow too full for its skin, and then the protoplasm divides into two parts and builds up a wall between them, and so one cell becomes two.
As a matter of fact, the two seed-leaves are not attached directly to each other, but each is attached to this tiny plant, or embryo, as it is called. The word "embryo" is a valuable one to use later, and its precise meaning can easily be fixed by always calling the young plant tucked away in the seed the embryo.
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