The sexual organs are occasionally entirely absent; a defect that is commonly associated with imperfect development of other parts, and especially with acephalia; a more or less important section of the apparatus is often defective, and one of the symmetrical organs, or one half of those organs which unite in the mesial line, may be absent; or again, one of these organs, or halves of organs, may be imperfectly developed, and its cavity contracted or closed up; or the apparatus may be complete in its different constituent portions and not have been duly developed, remaining permanently small and inefficient, so that the individual presents no sexual character.

Another defect of the sexual organs assumes the form of fissure, which is an arrest of various stages of embryonic development. The highest degree of this malformation is presented in the cloaca, which is to be explained as a persistence of the original sinus urogenitalis, or an imperfect separation of the parts that form the latter. A lower degree of this species of deformity is presented in the fissured condition of the sexual organs, in which case the foetal or female character predominates; we allude to the various fissures of the uterus, of the vagina, the penis, the urethra, or the scrotum, with or without a residuary trace of the urogenital sinus.

From these latter, apparently hermaphroditic formations, which depend upon an arrest of development, those pseudo-hermaphroditic formations, which consist in an excessive development of certain portions of the female organs of generation according to the male type, form a transition to true hermaphrodisia, i. e. hermaphrodisia per excessum; in which case certain portions of the sexual apparatus of an opposite sex are superadded.

In addition to the just-mentioned excess of formation we meet with another form in the shape of a repetition of certain sections of the apparatus, which may either present itself as excessive development of volume, or as precocity.

Besides congenital deviations of size, we find many that are acquired; in addition to those varieties which depend upon textural diseases, and particularly upon adventitious growths, they occur in the shape of hypertrophy and atrophy. The uterus in the female, the prostate in the male sex, are particularly liable to be affected by the former; the latter, independently of the process of involution (tabes senilis), which more or less uniformly involves the generative system, especially attacks the testes and the ovaries, and in a second degree the uterus.

The sexual organs are subject to numerous congenital deviations as to form; the uterus and its cavity are peculiarly liable in the female, the prostate in the male sex, to acquired malformations.

The position of the external sexual organs depends upon the congenital or acquired degreee of inclination of the pelvis, and other malformations. The most important congenital deviation of position of single organs affects the testes; the uterus presents very important acquired irregularities of this class.

Diseases of the tissues are peculiarly frequent in the female organs of generation; and among them the adventitious growths are most remarkable. We shall have occasion to advert in detail to many points of interest, relative to the morbid growths occurring in the sexual organs of either sex.