. Botany for agricultural students . Botany. USES OF THE PHOTOSYNTHETIC FOOD 273 to catching insects. Plants with such leaves are often called "carnivorous plants " or "insectivorous ; The "Pitcher Plants " are so named because the leaves form tubes of urns of various forms, which contain water, and to these pitchers insects are attracted and then drowned. {Fig. 245.) The plants known as " Sundews" have their leaves spread on the ground and clothed with secreting hairs. {Fig. 2Jfi.) These secre- tions not only entangle in- sects but digest them. I
. Botany for agricultural students . Botany. USES OF THE PHOTOSYNTHETIC FOOD 273 to catching insects. Plants with such leaves are often called "carnivorous plants " or "insectivorous ; The "Pitcher Plants " are so named because the leaves form tubes of urns of various forms, which contain water, and to these pitchers insects are attracted and then drowned. {Fig. 245.) The plants known as " Sundews" have their leaves spread on the ground and clothed with secreting hairs. {Fig. 2Jfi.) These secre- tions not only entangle in- sects but digest them. In the "Venus Flytrap," por- tions of the leaves work like steel traps and hold the in- sects fast until digested. {Fig. 247.). Fig. 247.—Venus Flytrap, showing the leaves which open and close in catch- ing insect? Uses of the Photosynthetic Food In plants, as in animals, the chemical processes upon which growth and other vital activities depend are both constructive and destruc- tive. While the simpler ele- ments are being transformed into complex substances, complex substances through respiration and other destructive processes are being broken into simpler substances. These chemical transformations constitute metabolism, and are said to be anabolic when constructive and catabolic when destructive. Through the plant's metabolic processes numerous substances are formed, of which protoplasm, proteins, sugars, starches, fats, oils, hemicellulose, amino-com- pounds, cellulose, wood, cutin, suberin, enzymes, acids, tannins, glucosides, and alkaloids are common ones. All of these sub- stances are thought to be of some use to the plant, although the exact function of some of them is not definitely known. The photosynthetic grape sugar, since there is much evidence that in most cases it is the chief food formed by photosynthesis, may be regarded as a foundational food; for the photosynthetic. Please note that these images are extracted from scanned page images that may hav
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
