The Ohio Naturalist Vol 7

Author : John H. Schaffner
Publisher :
ISBN 13 : 9781332305247
Total Pages : 346 pages
Book Rating : 4.3/5 (52 download)

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Download or read book The Ohio Journal of Science (Continuation of the Ohio Naturalist), Vol. 17 written by John H. Schaffner and published by . This book was released on 2015-08-05 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from The Ohio Journal of Science (Continuation of the Ohio Naturalist), Vol. 17: Official Organ of the Ohio Academy of Science and of the Ohio State University Scientific Society; 1916-17 It may be granted that the cytological work of the past fifteen years has established an undoubted connection between chromosomes and sex. One may even magnanimously neglect to point out that in some cases, for example, in the phylloxerans and probably the rotifers, the sex-determining event, as shown by differences in the size of the eggs, precedes the differential behavior of the chromosomes, and that the chromosomes are therefore not players, but pawns. It may be admitted that the experimental work of Baltzer, Gates, Lutz, Stomps, and others, has fixed upon the chromosomes the responsibility of producing certain hereditary features of the organisms they studied. Yet, after making all these admissions, it is possible to accept as demonstrated certain facts which plainly indicate an influence upon hereditary processes, of something else than chromosomes. It is my purpose first to point out a few of these facts; and second to show how we may cherish this evidence, without spewing the chromosomes out of our mouths, like the angel of Laodicea, and likewise without straddling. Among the foremost evidence of the importance of cytoplasm in heredity is that derived from cases of inheritance only through the mother. Inheritance only through the mother is in strong contrast to one of the earliest evidences in favor of the nucleus as the bearer of hereditary factors. It was long ago pointed out that father and mother shared equally in fixing the nature of the offspring; but that the spermatozoa carried little or no cytoplasm, while the egg was, from the standpoint of volume, chiefly cytoplasm. The chief difference between egg and sperm is that the former is lumbered down with a mass of passive cytoplasm and yolk, from which the sperm is practically free. When, then, we find a case of inheritance only through the mother, there is left little room for any conclusion but that this inheritance depends upon the cytoplasm of the egg, or upon something included in the cytoplasm. The facts in one such case are these. In the old-fashioned four o'clocks of grandmother's garden, Mirabilis Jalapa, there is a variety named albomaculata, which has variegated leaves. The structural basis of the variegation is the fact that the chromatophores in the yellowish white patches are not bright green, but more or less blanched. The amount of green and white varies greatly in different plants. Furthermore, whole branches may be green, other whole branches white. 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.