It is difficult to speak very decisively as to the function of the labia minora. They doubtless exert some amount of protective influence over the entrance to the vagina, and in this way correspond to the lips of the mouth after which they are called. They fulfill, however, one very definite though not obviously important function which is indicated by the mythologic name they have received. There is, indeed, some obscurity in the origin of this term, nymphæ, which has not, I believe, been satisfactorily cleared up. It has been stated that the Greek name νύμφη has been transferred from the clitoris to the labia minora. Any such transfer could only have taken place when the meaning of the word had been forgotten, and νύμφη had become the totally different word nymphæ, the goddesses who presided over streams. The old anatomists were much exercised in their minds as to the meaning of the name, but on the whole were inclined to believe that it referred to the action of the labia minora in directing the urinary stream. The term nymphæ was first applied in the modern sense, according to Bergh, in 1599, by Pinæus, mainly from the influence of these structures on the urinary stream, and he dilated in his De Virginitate on the suitability of the term to designate so poetic a spot.[[93]] In more modern times Luschka and Sir Charles Bell considered that it is one of the uses of the nymphæ to direct the stream of urine, and Lamb from his own observation thinks the same conclusion probable. In reality there cannot be the slightest doubt about the function of the nymphæ, as, in Hyrtl's phrase, "the naiads of the urinary source," and it can be demonstrated by the simplest experiment.[[94]]
The nymphæ form the intermediate portal of the vagina, as the canal which conducts to the womb was in anatomy first termed (according to Hyrtl) by De Graaf.[[95]] It is a secreting, erectile, more or less sensitive canal lined by what is usually considered mucous membrane, though some have regarded it as integument of the same character as that of the external genitals; it certainly resembles such integument more than, for instance, the mucous membrane of the rectum. In the woman who has never had sexual intercourse and has been subjected to no manipulations or accidents affecting this region, the vagina is closed by a last and final gate of delicate membrane—scarcely admitting more than a slender finger—called the hymen.
The poets called the hymen "fios virginitatis," the flower of virginity, whence the medico-legal term defloratio. Notwithstanding the great significance which has long been attached to the phenomena connected with it, the hymen was not accurately known until Vesalius, Fallopius, and Spigelius described and named it. It was, however, recognized by the Arab authors, Avicenna and Averroes. The early literature concerning it is summarized by Schurig, Muliebria, 1729, Section II, cap. V. The same author's Parthenologia is devoted to the various ancient problems connected with the question of virginity.
To say that this delicate piece of membrane is from the non-physical point of view a more important structure than any other part of the body is to convey but a feeble idea of the immense importance of the hymen in the eyes of the men of many past ages and even of our own times and among our own people.[[96]] For the uses of the feminine body, or for its beauty, there is no part which is more absolutely insignificant. But in human estimation it has acquired a spiritual value which has made it far more than a part of the body. It has taken the place of the soul, that whose presence gives all her worth and dignity, even her name, to the unmarried woman, her purity, her sexual desirability, her market value. Without it—though in all physical and mental respects she might remain the same person—she has sometimes been a mark for contempt, a worthless outcast.[[97]]
So fragile a membrane scarcely possesses the reliability which should be possessed by a structure whose presence or absence has often meant so much. Its absence by no means necessarily signifies that a woman has had intercourse with a man. Its presence by no means signifies that she has never had such intercourse.
There are many ways in which the hymen may be destroyed apart from coitus. Among the Chinese (and also, it would appear, in India and some other parts of the East) the female parts are from infancy kept so scrupulously clean by daily washing, the finger being introduced into the vagina, that the hymen rapidly disappears, and its existence is unknown even to Chinese doctors. Among some Brazilian Indians a similar practice exists among mothers as regards their young children, less, however, for the sake of cleanliness than in order to facilitate sexual intercourse in future years. (Ploss and Bartels, Das Weib, vol. i, Chapter VI.) The manipulations of vaginal masturbation will, of course, similarly destroy the hymen. It is also quite possible for the hymen to be ruptured by falls and other accidents. (See, e.g., a lengthy study by Nina-Rodrigues, "Des Ruptures de l'Hymen dans les Chutes," Annales d'Hygiène Publique, September, 1903.)
On the other hand, integrity of the hymen is no proof of virginity, apart from the obvious fact that there may be intercourse without penetration. (The case has even been recorded of a prostitute with syphilitic condylomata, a somewhat masculine type of pubic arch, and vulva rather posteriorly placed, whose hymen had never been penetrated.) The hymen may be of a yielding or folding type, so that complete penetration may take place and yet the hymen be afterwards found unruptured. It occasionally happens that the hymen is found intact at the end of pregnancy. In some, though not all, of these cases there has been conception without intromission of the penis. This has occurred even when the entrance was very minute. The possibility of such conception has long been recognized, and Schurig (Syllepsilogia, 1731, Section I, cap. VIII, p. 2) quotes ancient authors who have recorded cases. For some typical modern cases see Guérard (Centralblatt für Gynäkologie, No. 15, 1895), in one of whose cases the hymen of the pregnant woman scarcely admitted a hair; also Braun (ib., No. 23, 1895).
The hymen has played a very definite and pronounced part in the social and moral life of humanity. Until recently it has been more difficult to decide what precise biological function it has exercised to ensure its development and preservation. Sexual selection, no doubt, has worked in its favor, but that influence has been very limited and comparatively very recent. Virginity is not usually of any value among peoples who are entirely primitive. Indeed, even in the classic civilization which we inherit, it is easy to show that the virgin and the admiration for virginity are of late growth; the virgin goddesses were not originally virgins in our modern sense. Diana was the many-breasted patroness of childbirth before she became the chaste and solitary huntress, for the earliest distinction would appear to have been simply between the woman who was attached to a man and the woman who followed an earlier rule of freedom and independence; it was a later notion to suppose that the latter woman was debarred from sexual intercourse. We certainly must not seek the origin of the hymen in sexual selection; we must find it in natural selection. And here it might seem at first sight that we come upon a contradiction in Nature, for Nature is always devising contrivances to secure the maximum amount of fertilization. "Increase and multiply" is so obviously the command of Nature that the Hebrews, with their usual insight, unhesitatingly dared to place it in the mouth of Jehovah. But the hymen is a barrier to fertilization. It has, however, always to be remembered that as we rise in the zoölogical scale, and as the period of gestation lengthens and the possible number of offspring is fewer, it becomes constantly more essential that fertilization shall be effective rather than easy; the fewer the progeny the more necessary it is that they shall be vigorous enough to survive. There can be little doubt that, as one or two writers have already suggested, the hymen owes its development to the fact that its influence is on the side of effective fertilization. It is an obstacle to the impregnation of the young female by immature, aged, or feeble males. The hymen is thus an anatomical expression of that admiration of force which marks the female in her choice of a mate. So regarded, it is an interesting example of the intimate manner in which sexual selection is really based on natural selection. Sexual selection is but the translation into psychic terms of a process which has already found expression in the physical texture of the body.
It may be added that this interpretation of the biological function of the hymen is supported by the facts of its evolution. It is unknown among the lower mammals, with whom fertilization is easy, gestation short and offspring numerous. It only begins to appear among the higher mammals in whom reproduction is already beginning to take on the characters which become fully developed in man. Various authors have found traces of a rudimentary hymen, not only in apes, but in elephants, horses, donkeys, bitches, bears, pigs, hyenas, and giraffes. (Hyrtl, Op. cit., vol. ii, p. 189; G. Gellhoen, "Anatomy and Development of the Hymen," American Journal Obstetrics, August, 1904.) It is in the human species that the tendency to limitation of offspring is most marked, combined at the same time with a greater aptitude for impregnation than exists among any lower mammals. It is here, therefore, that a physical check is of most value, and accordingly we find that in woman alone, of all animals, is the hymen fully developed.