After the root has grown about an inch it begins to branch; and in about two weeks these branch branch-roots are searching the soil for food all around the main root.
The shoot meanwhile is growing in length and thickness. It remains folded up until it reaches the air and light. Then its leaves open out and turn from a creamy colour to bright green.
One small box of seeds was placed in a dark cupboard. These beans grew much more quickly than those grown in the light; but they were pale, lank, and sickly. They never turned green.
From this the boys learned that the green colour of leaves and stems is due to the action of light.
Uncle George took a few grains of wheat and placed them upon wet blotting-paper. A tumbler turned upside down was placed over them.
In a few days the children saw that a few small roots had grown out from the end of each grain.
When these roots had grown to about half an inch in length, great tufts of long slender hairs sprang out all round them near their tips. These, their uncle told them, were “root-hairs.”
The root-hairs of a plant are so fine that they are always torn off when we dig or pull a plant out of the ground. It is by means of these slender root-hairs that the plant is able to suck water out of the soil; and this water always contains a very little plant-food in it.
The boys noticed that the wheat grain did not sprout in the same way as the bean seed. Instead of one stout little root, three usually came out. The tiny shoot seemed to grow from the outside of the grain, and the two large masses of plant-food were missing.
