Other plants of lowlier mind creep along the ground. The prince’s pine forms a strong, thick mat, cleaving to every root, twig, grass-stem, in its way, striking rootlets here and there, until only a strong hand and a firm wrench can drag it from the earth, its mother. Cinque-foil and its cousin, strawberry, send out runners from all sides, which root and shoot up new plants until the whole bed is a solidarity, and would so remain did not the thankless plants keep all the food and moisture for themselves, and deliver over the runners to death by starvation.
The walking fern has a most original way of getting over the ground. It bends its slender frond and starts a root by extending the tip of the mid-rib; so it sets up a new plant and is anchored fast on all sides by its rooted frond tips, covering the ground with a rich carpet of verdure. The variety of runners along the ground is as great as the climber. All motion of the plant is a form of growth. The plant grows by day and by night, but more by day, as light and heat are incentives to growth.
Interesting as is the study of plant motion, let us forsake it and consider for a little plant food. The plant receives food from earth, water, and air. The earth gives the plant sulphur, iron, soda, magnesia, phosphorus, and other mineral substances. These are all fed to the plant in a solution of water.
From the rain the plant receives as food hydrogen and forms of ammonia.
From air the plants absorb carbon, oxygen, nitrogen, and ammonia; very much of the first, little of the second, and very little of the others.
When plants grow out-of-doors, the winds, dews, and rains free the leaves from accumulations of dust which obstruct the pores and hinder the receiving of food. In very dry and dusty seasons we notice that the plants become sickly from the stopping of the pores. Plants need clean skins as human beings do.
House plants should be well washed all over now and then, to admit of their getting their proper amount of food from the air.
INSECT EATERS
Certain classes of plants use a portion of animal food. We are accustomed to the idea of animals eating plants, but when we see the tables turned, and the plants eating animals, that is queer, indeed! The animal food of the “flesh-eating,” or carnivorous, plants is really the juice sucked from the bodies of insects.