. Beginners zoology. Zoology. BEGINNERS' ZOOLOGY Energy in the Organic World. —We see animals exerting energy; that is, we see them moving about and doing work. Plants are never seen acting that way; yet they need energy in order to form their tissues, grow, and raise themselves in the air. Source of Plant Energy.—We notice that green plants thrive only in the light, while animal growth is largely in- dependent of light. In fact, in the salt mines of Poland there are churches and villages below the ground, and children are born, become adults, and live all their lives below ground, without see
. Beginners zoology. Zoology. BEGINNERS' ZOOLOGY Energy in the Organic World. —We see animals exerting energy; that is, we see them moving about and doing work. Plants are never seen acting that way; yet they need energy in order to form their tissues, grow, and raise themselves in the air. Source of Plant Energy.—We notice that green plants thrive only in the light, while animal growth is largely in- dependent of light. In fact, in the salt mines of Poland there are churches and villages below the ground, and children are born, become adults, and live all their lives below ground, without seeing the sun. (That these people are not very strong is doubtless due more to want of fresh air and other causes than to want of sunlight.) ^ T/ie need of plants for C xf^ sunlight shozvs that they must obtain something front the sun. This has been found to be energy. This enables them to lift their stems in growth, and form the various structures called t'.ssues which make up their stems and leaves. It is noticed that they take in food and water from the soil through their roots. Experiments also show that green plants take in through pores (Fig. 1), on the surface of their leaves, a gas composed of carbon and oxygen, and called carhon dioxide. The energy in the sunlight enables the plant to separate out the carbon, of the carbon dioxide and to build mineral and w^ater and carbon. ^^- Fig. I. — Surfaces of a Leaf, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Coleman, Walter M. Toronto : Macmillan
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1921
