Publication (Volume 46) (Paperback)

This historic book may have numerous typos, missing text or index. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. 1910. Not illustrated. Excerpt: ... NUCLEAR PHENOMENA OF SEXUAL REPRODUCTION IN ANGIOSPERMS PROFESSOR D. M. MOTHER Indiana University What constitutes sexual reproduction, fertilization or fecundation is so variously set forth in botanical literature that one naturally approaches a discussion of this subject with some timidity. Having been assigned the group angiosperms, in which a definition of sexual phenomena may be made more specific by concrete illustration, it seemed at the outset that a part of my task, at least, was simpler than that of some of my colleagues who take part in this section of our program; but a moment's thought convinced me that what might be gained from this limitation of my field was probably much less than the opportunities offered by the scope and diversity of phenomena in groups of lower plants. In the preparation of this paper, the writer has kept clearly in mind the fact that the phenomena of sexual reproduction implies explicitly that a special significance is attached to the nucleus as in a large measure distinct from any function, or role of the cytoplasm; consequently he will deal first chiefly with nuclear behavior, leaving a discussion of the relation of nucleus and cytoplasm to be dealt with in a later paragraph. Sexual reproduction in phanerogams implies the union of especially developed cells known as gametes, and the development of an individual plant from such union. While in this process the union of the nuclei is held to be more important, it is not inferred that the part taken by the cytoplasm is unimportant, but the writer does insist that the cytoplasm plays a secondary role in the most important results of sexual reproduction, namely, the transmission of parental characters. It will be maintained also that the union of mere gametophytic cells does not...