Form And Structure Of Certain Plant Hybrids In Comparison With The Form And Structure Of Their Parents PDF Download

Excerpt from Form and Structure of Certain Plant Hybrids, in Comparison With the Form and Structure of Their: Parents a Thesis Presented to the Faculty of the Graduate School, of Cornell University for the Degree of Doctor of Philosophy Notwithstanding the fact that plant hybrids have claimed much attention for many years and have been considered as creations of special interest by gardeners, horticulturalists, and scientists in general, with few exceptions, only their external or morphological characters have been studied. The histological characters, although numerous, well defined, and fundamental to the plant in its organization, have been largely overlooked, and their inheritance not considered. In this investigation, special attention has been paid to the microscopical structure of the hybrids studied and to inheritance of histological characters. An effort was also made to determine whether or not there is a definite relation existing between external and internal characters, or a correlation in the inheritance of the two sets of characters. In taking up this study, the first task was to produce hybrids between parents as widely separated in histological and morphological characters as possible. To this end the greater part of the summer of 1908 was spent trying to make crosses between widely distinct plants. Crosses were attempted between plants belonging to different species, genera and even families. As a result, hybrids were obtained between three very distinct species of Nicotiana, - Nicotiana Tabacum x N. sylvestris, and N.Tabacum x N. alata, and also a hybrid between plants belonging to the two genera Raphanus and Brassica, Raphanus sativus (Radish) x Brassica oleracca var. caulo-rapa (Kohlrabi). These first generation hybrids, together with plants from self fertilized seed of the parent plants were grown during the summer of 1909. During this summer photographs were made, notes and measurements taken, and material fixed and preserved for histological study. Chrom-acetic arid fixer made up after the formula in common use, and Gilson's fixer were used. Most of the material was imbedded in celloidin for sectioning, but paraffin was used in all cases wherever possible. In addition to the hybrids mentioned above, the structure of certain others, was studied in some detail. 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.