At all events, there can be no question of a compression of the spermatic cord in any way, for it could not be accomplished, either manually or with the aid of various kinds of apparatus, without giving rise to excessive pain.
In this case, as Hencke in his time explained, the cremaster muscle raises the testicle up towards the inguinal canal. At complete erection the testicle is drawn up and pressed against the inguinal ring. This gives more favorable conditions for leading the semen forward from this one of the two testicles; and this portion of the semen is used for impregnation, to which end also a favorable attitude and a free passage into the ovary must be provided. According to the views of the author, this method, if adopted in procreation, will lead to the desired result of producing a given sex. Exceptions are admitted. Exceptions occurred in five families with twenty-three children. The author clings firmly to his theory that each testicle possesses its own special spermatozoa and each ovary its special ova, in which a given sex is already in existence, and from which in fruitful intercourse male or female individuals originate.
Next after a number of theories which have been current on this subject, we reach some others, to which more or less value has been attributed. Morello attached weight to the concentration of the semen. Thin, liquid semen was to be favorable to the production of females; thick semen produced males. According to modern theories, based upon observation of invertebrate animals (O. Hertwig, Balfour, Landois, Minot, and others), it appears improbable that this position can be maintained. The supporters of this theory assert that a single spermatozoon suffices for the fertilization of an ovule, or to develop the ovum into a so-called "oosperm," that is to say, to form a really fertilized ovum. (Perhaps the excess of semen serves for the earliest nutritive processes of the ovum; which would, however, be difficult to prove.) This fact has been also confirmed in the case of the higher animals, and it might be in a similar manner brought to an issue in the case of man. However, observations of this kind have not yet proved possible with man. But in the case when several spermatozoa penetrate the interior of a single ovum, anomalies in the process of development result from the formation of several nuclei. Such ova, also, perhaps in consequence of excess of semen, are very often aborted and perish.