Elements of biology; a practical Elements of biology; a practical text-book correlating botany, zoology, and human physiology elementsofbiolog00hunt Year: [c1907] 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
Elements of biology; a practical Elements of biology; a practical text-book correlating botany, zoology, and human physiology elementsofbiolog00hunt Year: [c1907] 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
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Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
