"Then tell me," said he, "what the root has to do for the plant.""It has to hold the plant firmly in the soil," said Norah, "so that the winds and the rain may not tear it up. It has, besides that, to feed the plant with food from the soil.""Quite right," said Fred. "Now I am going to try and tell you how the root feeds the plant. Come out into the garden, and we will get some roots. Suppose I dig up this carrot.
"Now look,"he went on, "at these fine, white threads all over the carrot. Teacher says they are the root-hairs.""Yes," said Willie, "and they have more to do thanany other part of the root. They are the feeders of the plant.""Will is quite right," said Fred. "Every morsel of food, which the plant gets from the soil, has to pass up through those little hairs.
"Teacher told us," he went on, "that these root- hairs are made up of a great many tiny cells or cases, with the thinnest of thin walls. Our eyes are not sharp enough to see them now. But that is what they really are. The thin cells act very much like a sponge. The sponge, you know, absorbs liquids. These root-hairs do the same.
"Now just think over our chat about rock-salt.
