Intersexes in the human species—not only the extreme pathological cases represented by the so-called "hermaphrodites," but also merely masculine women and effeminate men—have been the subject of serious remarks as well as literary gibes from the earliest times. The Greeks called these people urnings. Schopenhauer was interested in the vast ancient literature and philosophy on this subject. The 19th century produced a copious psychological treatment of warped or reversed sexual impulses by such men as Moll, Krafft-Ebing and Havelock Ellis. Otto Weiniger[[10]] collected a mass of this philosophy, literature, psychology, folklore and gossip, tied it together with such biological facts as were then known (1901) and wove around it a theory of sex attraction.[[A]] The same material was popularized by Leland[[11]], Carpenter[[12]] and W.L. George[[13]] to support quite different views.
NOTE: Weiniger thought he could pick, merely by observing physical type, people who would be sexually attracted to each other. There is much ground for scepticism about this. To begin with, the biological experiments indicate that intersexes are peculiarly likely to appear where two or more races are mixed. So far, there is no exact knowledge about the amount or kind of sex difference in each race. As Bateson remarks (Biol. Fact & the Struct. of Society, p.13), one unversed in the breeds even of poultry would experience great difficulty and make many mistakes in sorting a miscellaneous group of cocks and hens into pairs according to breed. If this is true in dealing with pure breeds, "in man, as individuals pure-bred in any respect are very rare, the operation would be far more difficult." In the human species sexual attraction also obviously depends upon many factors which are not purely biological; it is rather a complicated sentiment than an instinct.
George's statement that "there are no men and ... no women; there are only sexual majorities"[p.61, op. cit.] has been widely quoted. The feminists, he adds, "base themselves on Weininger's theory, according to which the male principle may be found in woman, and the female principle in man." Unfortunately, George does not make clear what he means by "principle," so his theory, if he has one, is impossible to appraise in biological terms. From the embryonic idea expressed above, he deduces a very positive social philosophy of sex. The feminists, he says, "recognize no masculine or feminine 'spheres' and ... propose to identify absolutely the conditions of the sexes." So, while George seems to think much more highly of women than does Weininger, their philosophies come together, for quite different reasons, on the practical procedure of disregarding reproduction and letting the race go hang[[10, p.345]]. Weininger seems to recognize the dual basis for sex; George evidently does not quite follow him. Both entirely misconceived the real issues involved, as well as the kind of evidence required to settle them, as we shall see later in discussing adaptation and specialization.
Dr Blair Bell[[14,] [15]] has collected a mass of evidence on intersexes in the human species. This includes his own surgical and other cases, as well as many treated by his colleagues, and a very considerable review of the medical literature. He not only believes in degrees of femininity in women, but has worked out classifications which he claims to have found of great practical value in surgery.[[14, pp.166-7]] As noted above, Riddle discovered that his more feminine female pigeons were often killed by a dose of testicular extract which was practically harmless to a partially masculinized female. Sex in the human species being a matter of all the glands organized into a complex, the quantitative "strength" of that complex would be useful to know before removing any one secretion from it. Dr Bell states that the oöphorectomy operation (removal of ovaries) may be performed upon a masculine type of woman with "little disturbance of the metabolism..." But he thinks that the degree of masculinity should always be carefully observed before undertaking such operations, which in some cases have most undesirable effects.
At one end of the scale, this surgeon places the typically feminine woman in all her characteristics—with well-formed breasts, menstruating freely and feminine in instincts—he says "mind." The intermediate grades consist, he says, of women whose metabolism leans toward the masculine type. Some have sexual desires but no maternal impulse. Others desire maternity but take no interest in sex activity, or positively shun it. The physical manifestations of masculine glandular activity take the form of pitch of voice, skin texture, shape and weight of bones, etc. Some of the inter-grades are a little hard to define—the human species is such an inextricable mixture of races, etc.; but Dr Bell does not hesitate to describe the characteristically masculine woman of the extreme type, who "shuns both sexual relations and maternity...(She) is on the fringe of femininity. These women are usually flat-breasted and plain. Even though they menstruate, their metabolism is often for the most part masculine in character: indications of this are seen in the bones which are heavy, in the skin which is coarse, and in the aggressive character of the mind...If a woman have well-developed genitalia, and secondary characteristics, she usually is normal in her instincts. A feebly menstruating woman with flat breasts and coarse skin cannot be expected to have strong reproductive instincts, since she is largely masculine in type..."
The glandular and quantitative explanation of sex, instead of being abstruse and complicated, brings the subject in line with the known facts about inheritance generally. The dual basis for femaleness and maleness in each individual simply means that both factors are present, but that only one expresses itself fully. The presence of such a dual basis is proved by the fact that in castration and transplantation experiments both are exhibited by the same individual in a single lifetime. In the case of the Free-Martin cattle, even the female sex-glands are modified toward the male type to such an extent that they were long mistaken for testes. The same applies to some glands found in human "hermaphrodites," as Dr Bell's plates show.
The peculiar complication of the chemical complex determining sex in these mammalian forms, involving all the glands and hence the entire body, makes it problematical whether a complete (functional) reversal is possible, at least after any development whatever of the embryo has taken place. On the other hand, the fact that such complete transformations have not so far been observed by no means proves their non-existence. Their being functional, and hence to all external appearances normal, would cause such animals to escape observation.
Latent traits of the opposite sex of course immediately suggest recessive or unexpressed characters in the well-known Mendelian inheritance phenomena. In the bird-castration cases, we saw that to remove the inhibiting sex glands caused previously latent characters to act like dominant or expressed ones. The case of horns in sheep, investigated by Professor Wood[[16]], is so similar that it seems worth summarizing, by way of illustration.