The hymen, however various its forms may be, consists of a double layer of mucous mem, brane, containing between its lauainm a small quantity of fibrous tissue and blood-vessels. It is of variable degrees of thickness, being in some subjects very strong and tough, and in others forming a very slender lamina. Its situation is at the entrance of the vagina. Although the depth at which it is placed within the vulva varies in different subjects, according to the thickness of the labia, and the size of the nymphm and vestibule. Occa sionally, as already stated, one or more plicm of the vaginal mucous membrane, more than usually developed, form constrictions at a higher point within the canal, but the term hytnen cannot with propriety be applied to any of these.
The presence of the hymen, although it raises a strong probability of virginity, y et affords no certain evidence upon that point, nor does its absence establish the contrary.
The hymen is commonly said to be ruptured on the occasion of a first complete intercourse, but the expression unfolded would probably, in many instances, more accurately represent the mode of its disappearance. Whenever the hymen presents any considerable mem branous surface, doubtless a real laceration occurs, but in the cases in which it takes the form of a crescentic fold, or of a puckered rosette, instead of being lacerated, it probably becomes unfolded or flattened out, and so dis appears, just as the ordinary vaginal folds are obliterated, by frequent intercourse or by parturition, without any rupture.
Upon the presumption that the hymen is always lacerated a certain hypothesis has been raised, namely, that the little fleshy bodies occasionally observed near the orifice of the vagina, termed carunculce myrtaformes, consti tute the remains of that membrane. But, notwithstanding a great amount of evidence that has been collected regarding the myrti form bodies, it cannot be shown that these are anything more than accidental and uncertain formations, having nothing necessarily to do with the hymen.
The hymen may. be broken by accident, or may become obliterated by the frequent em ployment of vaginal injections, and in other like modes. Or, from constant leucorrhcea, the parts may become so relaxed that a dis tinct membranous fold can be no longer dis cerned at the vaginal orifice, although there may have been no loss of virginity.
On the other hand, impregnation may take place without destruction of the hy-men, which has frequently been found entire at the time of labour, and even in women affected by sy philis.*
Sebaceous and Muciparous Glands and Fol licles of the Vulva. — The sebaceous follicles correspond with the male preputial follicles. They are scattered over the nymphm, clitoris, and inner surface of the labia. Their secretion contains butyric acid and has a strong and somewhat ammoniacal odour. This occasion ally becomes highly irritating, especially when cleanliness is neglected.
The niuciparous follicles are arranged in groups, the principal ones being situated upon the vestibule (vestibular follicles, fig. 480. v), around and upon the sides of the meatus urinareus (urethral follicles,fig. 480. u), and at the sides of the entrance of the vagina (lateral follicles of the vaginal orifice, fig. 480. va).
The muciparous follicles are composed of a tlelicate vascular mucous membrane arranged in the form of short mucous crypts, or con sist of simple or branched tubules ending in a cul-de-sac. The vestibular follicles are of the former kind and the urethral of the latter.
All these vulvar follicles secrete a viscid mucus, the quantity of which becomes consi derably increased under excitement or irrita tion. It serves to lubricate the several parts of the vulva.
The milvo-vaginal glands, termed also the glands of Bartholin and of Duvernay, consist of two conglomerate glands of the size of a haricot bean, variable in form, and of a pale reddish yellow colour, which are placed one upon each side of the vagina near the entrance (fig. 480. g). They are lodged beneath the superficial perineal fascia, having their inner side united to the vagina by areolar tissue, and their outer surface in relation with the con strictor muscle of the vagina. The lobules composing this gland send off tubules which at its upper and fore part unite to form an excre tory duct that proceeds horizontally forwards as far as the vaginal orifice, upon the side of which it terminates just within the nymphze and externally to the hymen. The orifice of the duct (d) is covered by a falciform fold of mucous membrane, which renders its discovery sometimes difficult.
This gland secretes a viscid fluid resembling somewhat the prostatic fluid and having a pe culiar odour. Under excitement its secretion is rapidly formed and, like the contents of the salivary duct, is sometimes emitted in a jet. This gland is probably homologous with Cow per's gland in the male. In infancy and early life it is very small, attaining its full develop ment in the adult, and again diminishing and even disappearing in old age.