You know how thick and fleshy the roots of radishes, beets and turnips are. Well, go into the garden and see if you can find a spring radish or an early turnip that has sent up a flower stalk, blossomed and produced seeds. If you are successful, cut the root in two and notice that instead of being hard and fleshy like the young radish or turnip, it has become hollow, or soft and spongy (see [Fig. 6]). Evidently the hard, fleshy young root was packed with food, which it afterwards gave up to produce flower stalk and seeds.
A fourth use of the root, then, is to store food for the future use of the plant.
Experiment.—Plant a sweet potato or place it with the lower end in a tumbler of water and set it in a warm room. Observe it from day to day as it puts out new shoots bearing leaves and roots (see [Fig. 7]). Break these off and plant them in soil and you have a number of new plants. If you can get the material, repeat this experiment with roots of horse-radish, raspberry, blackberry or dahlia. From this we see that it is the work of some roots to produce new plants. This function of roots is made use of in propagating or obtaining new plants of the sweet potato, horse-radish, blackberry, raspberry, dahlia and other plants.
FIG. 4.
To show that plant-roots take water from the soil, the plants in A are suffering from thirst. B has sufficient water.[ToList]
FIG. 5.
To show that plant-roots take food from the soil. Both boxes were planted at the same time.[ToList]