The Biology, Physiology and Sociology of Reproduction, Also Sexual Hygiene; With Special Reference to the Male (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908. Excerpt: ... DEVELOPMENT. The development of the child within the uterus of the mother represents a chapter in the life history of every individual so important in its relations to maternity and paternity that every young man should be acquainted with at least its general features. As stated in the chapter on Reproduction, every living organism begins life as a single cell, or globule of protoplasm. In the case of the human subject, the cell from which each child begins its development is formed by the fusion of two cells or globules of protoplasm, one furnished by the mother, and called the ovum, or egg; the other furnished by the father, and called the spermatozoon. The egg is very much larger than the spermatozoon, and contains enough yolk material to afford nourishment for the embryo for a number of days. When the ovum reaches the finished state, which is called "maturity," it leaves the ovary, and is carried along the fallopian tube (see accompanying figure) into the uterus, where it usually finds a lodgment in the upper part, as shown in Figure I. Once the minute ovum has been caught in the projections of the velvety inner surface of the uterus, this thick velvety lining of the uterus in the neighborhood of the ovum begins a rapid growth, gradually enveloping the rapidly expanding ovum, as shown in Figures I and II of the accompanying plate. Within the ovum there are taking place some of the most marvelous changes in the whole life history of the individual. The nucleus of the fertilized egg, and the protoplasm which surrounds it, divide into two cells, then into four, eight, sixteen, etc. These divisions follow each other in such rapid succession that there are many hundreds of cells by the end of the first twenty-four hours. These cells soon begin to arrange t...