From the psychological point of view we are less interested in the internal sexual organs, which are most fundamentally concerned with the production and reception of the sexual elements, than with the more external parts of the genital apparatus which serve as the instruments of sexual excitation, and the channels for the intromission and passage of the seminal fluid. It is these only which can play any part at all in sexual selection; they are the only part of the sexual apparatus which can enter into the formation of either normal or abnormal erotic conceptions; they are the organs most prominently concerned with detumescence; they alone enter normally into the conscious process of sex at any time. It seems desirable, therefore, to discuss them briefly at this point.
Our knowledge of the individual and racial variations of the external sexual organs is still extremely imperfect. A few monographs and collections of data on isolated points may be found in more or less inaccessible publications. As regards women, Ploss and Bartels have devoted a chapter to the sexual organs of women which extends to a hundred pages, but remains scanty and fragmentary. (Das Weib, vol. i, Chapter VI.) The most systematic series of observations have been made in the case of the various kinds of degenerates—idiots, the insane, criminals, etc.—but it would be obviously unsafe to rely too absolutely on such investigations for our knowledge of the sexual organs of the ordinary population.
There can be no doubt, however, that the external sexual organs in normal men and women exhibit a peculiarly wide range of variation. This is indicated not only by the unsystematic results attained by experienced observers, but also by more systematic studies. Thus Herman has shown by detailed measurements that there are great normal variations in the conformation of the parts that form the floor of the female pelvis. He found that the projection of the pelvic floor varied from nothing to as much as two inches, and that in healthy women who had borne no children the distance between the coccyx and anus, the length of the perineum, the distance between the fourchette and the symphysis pubis, and the length of the vagina are subject to wide variations. (Lancet, October 12, 1889.) Even the female urethral opening varies very greatly, as has been shown by Bergh, who investigated it in nearly 700 women and reproduces the various shapes found; while most usually (in about a third of the cases observed), a longitudinal slit, it may be cross-shaped, star-shaped, crescentic, etc.; and while sometimes very small, in about 6 per cent. of the cases it admitted the tip of the little finger. (Bergh, Monatsheft für Praktische Dermatologie, 15 Sept., 1897.)
As regards both sexes, Stanley Hall states that "Dr. F. N. Seerley, who has examined over 2000 normal young men as well as many young women, tells me that in his opinion individual variations in these parts are much greater even than those of face and form, and that the range of adult and apparently normal size and proportion, as well as function, and of both the age and order of development, not only of each of the several parts themselves, but of all their immediate annexes, and in females as well as males, is far greater than has been recognized by any writer. This fact is the basis of the anxieties and fears of morphological abnormality so frequent during adolescence." (G. S. Hall, Adolescence, vol. i, p. 414).
In accordance with the supreme importance of the part they play, and the intimately psychic nature of that part, the sexual organs, both internal and external, are very richly supplied with nerves. While the internal organs are very abundantly furnished with sympathetic nerves and ganglia, the external organs show the highest possible degree of specialization of the various peripheral nervous devices which the organism has developed for receiving, accumulating, and transmitting stimuli to the brain.[[77]]
"The number of conducting cords which attach the genitals to the nervous centers is simply enormous," writes Bryan Robinson; "the pudic nerve is composed of nearly all the third sacral and branches from the second and fourth sacral. As one examines this nerve he is forced to the conclusion that it is an enormous supply for a small organ. The periphery of the pudic nerve spreads itself like a fan over the genitals." The lesser sciatic nerve supplies only one muscle—the gluteus maximus—and then sends the large pudendal branch to the side of the penis, and hence the friction of coitus induces active contraction of the gluteus maximus, "the main muscle of coition." The large pudic and the pudendal constitute the main supply of the external genitals. In women the pudic nerve is equally large, but the pudendal much smaller, possibly, Bryan Robinson suggests, because women take a less active part in coitus. The nerve supply of the clitoris, however, is three or four times as large as that of the penis in proportion to size. (F. B. Robinson, "The Intimate Nervous Connection of the Genito-Urinary Organs With the Cerebro-Spinal and Sympathetic Systems," New York Medical Journal, March 11, 1893; id., The Abdominal Brain, 1899.)
Of all the sexual organs the penis is without doubt that which has most powerfully impressed the human imagination. It is the very emblem of generation, and everywhere men have contemplated it with a mixture of reverence and shuddering awe that has sometimes, even among civilized peoples, amounted to horror and disgust. Its image is worn as an amulet to ward off evil and invoked as a charm to call forth blessing. The sexual organs were once the most sacred object on which a man could place his hands to swear an inviolate oath, just as now he takes up the Testament. Even in the traditions of the great classic civilization which we inherit the penis is fascinus, the symbol of all fascination. In the history of human culture it has had far more than a merely human significance; it has been the symbol of all the generative force of Nature, the embodiment of creative energy in the animal and vegetable worlds alike, an image to be held aloft for worship, the sign of all unconscious ecstasy. As a symbol, the sacred phallus, it has been woven in and out of all the highest and deepest human conceptions, so intimately that it is possible to see it everywhere, that it is possible to fail to see it anywhere.
In correspondence with the importance of the penis is the large number of names which men have everywhere bestowed upon it. In French literature many hundred synonyms may be found. They were also numerous in Latin. In English the literary terms for the penis seem to be comparatively few, but a large number of non-literary synonyms exist in colloquial and perhaps merely local usage. The Latin term penis, which has established itself among us as the most correct designation, is generally considered to be associated with pendere and to be connected therefore with the usually pendent position of the organ. In the middle ages the general literary term throughout Europe was coles (or colis) from caulis, a stalk, and virga, a rod. The only serious English literary term, yard (exactly equivalent to virga), as used by Chaucer—almost the last great English writer whose vocabulary was adequate to the central facts of life—has now fallen out of literary and even colloquial usage.
Pierer and Chaulant, in their anatomical and physiological Real-Lexicon (vol. vi, p. 134), give nearly a hundred synonyms for the penis. Hyrtl (Topographisches Anatomie, seventh edition, vol. ii, pp. 67-69), adds others. Schurig, in his Spermatologia (1720, pp. 89-91), also presents a number of names for the penis; in Chapter III (pp. 189-192) of the same book he discusses the penis generally with more fullness than most authors. Louis de Landes, in his Glossaire Erotique of the French language (pp. 239-242), enumerates several hundred literary synonyms for the penis, though many of them probably only occur once.
There is no thorough and comprehensive modern study of the penis on an anthropological basis (though I should mention a valuable and fully illustrated study of anthropological and pathological variations of the penis in a series of articles by Marandon de Montyel, "Des Anomalies des Organs Génitaux Externes Chez les Aliénées," etc., Archives d'Anthropologie Criminelle, 1895), and it would be out of place here to attempt to collect the scattered notices regarding racial and other variations. It may suffice to note some of the evidence showing that such variations seem to be numerous and important. The Arab penis (according to Kocher) is slender and long (a third longer than the average European penis) and with a club-shaped glans. It undergoes little change when it enters the erect state. The clothes leaves it quite free, and the Arab practices manual excitement at an early age to favor its development.