The Annals And Magazine Of Natural History Including Zoology Botany And Geology 1883 Vol 12

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Publisher : Forgotten Books
ISBN 13 : 9780365954651
Total Pages : 486 pages
Book Rating : 4.9/5 (546 download)

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Download or read book The Annals and Magazine of Natural History, Vol. 4 written by and published by Forgotten Books. This book was released on 2018-04-18 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from The Annals and Magazine of Natural History, Vol. 4: Including Zoology, Botany, and Geology Although the changes that take place in the development of the vegetable ovule have long since occupied the attention of the ablest physiological botanists, it is evident that the real nature of its mode of growth is not yet well understood. My first object therefore is to Show that the doctrine upon this important subject, as taught in the best elementary works, is founded upon a very grave error. I was led into this inquiry by my desire to ascertain the nature of the fleshy covering enveloping the hard tunic in certain seeds and which appeared to me arilloid in its nature. This was contested by Dr. Asa Gray, who considered these two very Oppo site kinds of tunics as one baccate testa, both deriving a common origin from the primine of the ovule'l'. To this View I was um willing to subscribe and in my subsequent discussion of the subject, trusting fully to the orthodoxy of the common creed of botanists on the development of the ovule, I arguedi that the fleshy covering in question must be an expansion or growth of the placentary sheath, because it enclosed the raphe and so it is undoubtedly - but not in the light of an extraneous expansion, as I then viewed the question. This induced me to examine, b personal observation, the actual progress of growth of the ovule in certain plants which produce what have been called anatropal seeds; and I soon became convinced that I had been led into an error of inference, solely by my faith in the universally prevalent creed. Having lately completed the investigation of many Rhamnaceous and Anacara'iaceons seeds, in which several novel points of structure have been observed, which are difficult to explain, I am desirous, before the publication of these results, that the real nature of the development of the ovule should be well understood. I therefore now proceed to show that the doctrine upon this subject, as at present taught, is completely fallacious. 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.