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. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. Sections of white pine wood. (From Pinchot, Dept. of Agr.) outward to form little projections. Boards cut out of such a piece of wood will show the effect seen in many of the school desks, where the annual rings appear to form small elliptical markings. Knots. — Knots, as can be seen from the diagram, are branches which at one time started in their outward growth and were for some reason killed. Later, the tree, continu- ing in its outward growth, surrounded them and covered them up. A
. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. Sections of white pine wood. (From Pinchot, Dept. of Agr.) outward to form little projections. Boards cut out of such a piece of wood will show the effect seen in many of the school desks, where the annual rings appear to form small elliptical markings. Knots. — Knots, as can be seen from the diagram, are branches which at one time started in their outward growth and were for some reason killed. Later, the tree, continu- ing in its outward growth, surrounded them and covered them up. A dead limb should be pruned before such growth occurs. The Section of tree trunk , . • i • i» i i i showing knot. markmgs m bird s-eye maple are caused by. 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 Hunter, George William, 1873-1948. New York, American book company
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Keywords: ., boo, bookpublishernewyorkamericanbookcompany, booksubjectbiology