Whilst the male and female organs concerned in the production of semen and of ova are parallel and in strict correspondence, there is one striking deficiency in the male structure. The organ essential to the development of the human being, the organ into which the fertilized ovum (or human seed) must be brought for growth, is wanting in the male structure. This deficiency or difference between the sexes produces important physiological results. The special part which the male has to perform physically in the all-important reproductive function of sex finishes with the act of sexual congress, but it continues in the female. If conception has taken place, the results of this act become increasingly important. The life of sex, or all that belongs to the life of the race, as distinguished from the existence of the individual, becomes continuously and for a long time inseparable from the woman’s personal existence. Thus, all the relations of sex form a more important part of the woman’s than of the man’s life. Another important fact in sexual construction must be noted--viz., the nervous connections of the sexual organs. All the parts concerned in reproduction are in close communication with the brain by means of the nervous system and that enlargement of the spinal cord at the base of the brain, the medulla oblongata. If the nervous connection between the generative organs and the brain be severed, no consciousness of those parts will remain. But whilst the natural nervous connection exists, the influence of the brain upon those organs is continually felt, and information as to their changes is sent to the brain. This nerve connection exists from birth, although the formation of ova and semen (on which the power of reproduction depends) does not take place until a later date. Keen nervous sensation may, therefore, be perceived at any time after birth, although offspring cannot be produced until the more or less perfect establishment of reproductive power at puberty. It is of great importance to recognise this fact in the education of children. The above general statements respecting the division and correspondence of the sexual organs in the male and female, and their connection with the brain through the nervous system, are true of all the Mammalia, where, as in man, the reproductive power exists in two separate individuals. When, however, we consider the way in which these functions act in the work of reproduction, an important difference is observed between their action in man and in the lower animals. This difference places man physically in a different and superior category from the brute creation. The physiological arrangement of physical sex in man corresponds to the demands made by the increasing complexity of the sentiment of mental sex.