书城教材教辅科学读本(英文原版)(套装1-6册)
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第329章 第三册(154)

"The two parts of the germ grow-the radicle forcing its way down into the soil, the plumule upwards towards the surface, for light and air.""But I can"t see how these little germs can grow," said Norah. "Where do they get their food? It must be some time before the little root can grow enough to make its way into the soil, and then I think you told me that the root-hairs, which feed the plant, don"t come for some time. I can"t see how the little thing is to get any earth-food, and it certainly can"t get any air-food, for there are no leaves-no parts of it above the ground.""Well," said Fred, "I am not surprised to seeyou puzzled about this, Norah. But you may be sure everything is well arranged, although it is very wonderful. Those seed-leaves are simply a storehouse of food for the little germ, with just the proper kind of food, and just the proper quantity, to feed it till it can grow root-hairs to absorb earth- food from the soil, and leaves to breathe in air-food from the air.

"As soon as this is the case the seed-leaves witherand drop off."

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