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Résumé :
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Excerpt from Growth in TreesA tree may be considered as a tall cone of wood terminating in leafy expanses. The base of the cone is subdivided into myriads Of rootlets, through the surfaces of which the soil-solutions enter, and the water, passing upward, is transpired from the leaves. The trunk of a tree is largely composed of dead cells, but inclosing it is a thin sheet of spindle-form cambium cells1 in 2 to 10 or more layers, which in the growing season enlarge in thickness and divide lengthwise, those on the outside becoming transformed into cork and phloem and those on the inner into wood cells and vessels. Extending from the center of the trunk are thin sheets or rays of the medulla or pith Of the young stem. The most recently formed cells of these elements are still living and in some trees the medullary cells remain alive for several years, so that the woody cylinder Of the tree may comprise wood-cells or tracheids, vessels, and thin-wall ray cells, some of which are alive. External to the cambium are sieve cells, bast fibers, etc., and cork cells, inclosed in a bark which varies widely as to structure in different species.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
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