Author: W. Baldwin SpencerPublisher: Forgotten Books
ISBN: 9780332403656
Category : Science
Languages : en
Pages : 274
Book Description
Excerpt from Transactions of the Royal Society of Victoria, 1890, Vol. 2: Part 1 The primary object of the present paper is to Show how transverse sections of the petioles of Eucalypts may be used as valuable aids in the determination of species. Sections of thirty different kinds are here described and photographed, and they Show unmistakably, along with a general resemblance, differences which are more or less constant, and readily recognisable for each species. Anatomical characters of the leaf have already been successfully used in the discrimination of species belonging to other divisions of the vegetable kingdom.* Of course such characters, depending on a single organ, and apart from the aggregate of characters, are apt to be more or less artificial; but, when we consider that the parts shown in transverse section of the petiole are in organic connection with, and form an essential portion of, the Vital machinery of the plant, it need not excite surprise that they should vary in the different species, and be, to a certain extent, characteristic for each. We know that the leaf is simply a lateral expansion or extension of the stem or branch, usually bearing a bud in its axil, and its tissues are, as a rule, continuous with those of the stem, so that in it we have an epitome of the parts concerned in vegetative life - a point deserving of Special notice in this connection. Besides, the petiole, with which we are more particularly concerned, is capable of reproducing the entire plant from a small portion of it, as in the well-known instance of the ipecacuanha plant. The vegetative organs which, in some form or another, are absolutely necessary for the life of the individual, have been too little used in the discrimination of genera and species, while the reproductive organs have been too often almost exclusively relied upon. The anatomist (dealing with internal structure) and the systematist (often entirely occupied with external characters) must combine their results in order to arrive at a proper conception of the true system of nature. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This 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.
