The two most obvious changes in the eunuch are the absence of the beard and mustache and the small larynx, which produces a high-pitched voice. In both these respects man differs from woman; in both, however, the eunuch is like the boy as much as he is like the woman. It is not evident, therefore, whether the eunuch has retained the juvenile condition or has become more like the female. Moreover, there is the possibility that there is no difference in the present case between these two conditions. The distribution of hair on the pubis of the eunuch is often said to be more like that in the woman than that in the man, but there is apparently no sufficient evidence to show that this is more than the juvenile condition or an undeveloped condition of the male. As to the voice, there is no way of determining whether the voice of the eunuch is feminine or juvenile. The development of the mammæ in the eunuch would be a better test, but it does not appear from the literature on the subject that the mammary glands and the nipples of the eunuch are changed toward the female type. On the contrary, it appears rather that there is no such change. It is true that the tendency toward the accumulation of fat may give the eunuch a somewhat feminine appearance (since one of the foci of fat accumulation is in the region of the breasts), but this in itself can scarcely be claimed to be feminization, but due rather to the more slothful habit of the eunuch that tends to obesity.
A more suggestive resemblance is found in the narrowness of the shoulder girdle and broadness of the hips in the eunuch, but even these resemblances to the female should be regarded skeptically, since other changes in the bones that result from castration are certainly not a development toward the female type, but a peculiar specific effect of the absence of testes on the growth of the bones. For instance, the bones of the arms and legs are much longer in the eunuch than in either the normal man or woman, in fact, more in the direction of the male, who has longer legs than the female. The explanation usually given is that the ossification at the ends of the bones and of the epiphyses does not take place so soon as in normal men and women. The condition here is that characteristic of the juvenile state that is carried over into the adult, but whether the narrowness of the chest and shoulder girdle of the eunuch is correlated in some way with the more prolonged growth of the other bones has not, so far as I know, been determined. That there is no apparent connection between the shortness of the one and the greater length of the other does not necessarily lead to the conclusion that there is no such connection. For the present I think we must hold this point in reserve.
Steinach’s evidence for the feminized rats, if it may be extended to man, indicates that some of the female characteristics are due to the presence of the ovary holding in check the genetic possibilities of the female, as well as leading to the development of such characteristic traits as the mammæ, etc. In the case of the pelvis the female departs from the juvenile type of both sexes, and here one might look for a better criterion. It is stated that the pelvis of the ox is more like that of the female than it is like that of the male, and it has been said that this is true for the castrated rat and guinea-pig, but whether a simple enlargement of the juvenile pelvis would make it resemble the female type more than that of the male has not, so far as I know, been carefully examined. Should it prove here that this is the case, the evidence on this point would be no stronger than that for other character differences. As has been stated, Tandler and Grosz think that the changes in the skeleton of the ox, as well as those in the castrated cow (skull, pelvis, and limb bones), are due directly to loss of the gonads and are much the same in both. But their resemblance may possibly be due more to an enlarged juvenile condition rather than that either of them changes toward the normal skeleton of the other sex.
The statements that have been published concerning the effects of removal of the ovaries in woman are, on the whole, unsatisfactory and often contradictory. That the uterus and oviducts become smaller is expected from what is known to occur in other mammals, and is definitely recorded in the human female. That the breasts become smaller is stated to be the case, but whether because of an actual decrease in the glandular portion has not, so far as I know, been shown. That hair is likely to develop on the upper lip of woman without ovaries is also claimed as likely to occur, and this, too, is sometimes seen in old women, but if it is interpreted to mean an approach to the bearded condition of man it should be admitted that the development is hardly sufficient to invite such a comparison. Finally, it has been stated that the voice becomes deeper, more, therefore, like the male, but this has also been denied. If it could be established that the voice changes and that it was brought about by an enlargement of the larynx, similar to that which takes place when the larynx of the boy changes to that of the man, it might seem not improbable that the change was toward that of the opposite sex. This would mean that the ovary produces some substance that prevents the enlargement of the larynx in the female. But since it has been shown that the enlargement in the male is caused by the development of the testes, and that this enlargement is prevented by castration, a paradoxical situation would present itself, viz, that the testes cause the larynx to enlarge in the male and the ovary prevents the enlargement in the female. Until convincing evidence is forthcoming, the question is better left undecided.
B. Evidence from Birds.
Probably a greater difference in the secondary sexual characters is shown in birds than in any other group. It is true that there are species, such as the doves and pigeons, in which the plumage of the male is much like that of the female, but this is the exception rather than the rule. At the other extreme are species like birds of paradise, hummingbirds, fowls, pheasants, ducks, and many passerines, in which the plumage of the two sexes is entirely different. Our knowledge as to the relation between the nuptial plumage of the male and the condition of the sex-organs rests largely on information gained by castration in poultry and ducks and on the assumption of the nuptial plumage in several species only at the mating season.
John Hunter in 1780 described a pheasant with male plumage. His account of a similar change in a pea fowl is so complete that I venture to quote it in full:
“Lady Tynte had a favorite pyed pea-hen, which had produced chickens eight several times; having moulted when she was about eleven years old, she astonished the lady and her family by showing the feathers peculiar to the other sex, and appearing like a pyed peacock. In this process the tail, which was similar to that of a cock, first appeared after moulting. In the following year she moulted again, and produced the same feathers. In the third year she did the same; at the same time she had spurs similar to those of a cock. She died in the following winter during the hard frost, namely, in the winter 1775-6. She never bred after this change in her plumage. This bird is now preserved in the Museum of Sir Ashton Lever.”[17]
“From what has been related of these two birds, may it not reasonably be inferred that it seems probable that all those wild pheasants of the female sex, which are found with the feathers of the cock, had changed the nature of their feathers, particularly at a certain age?
“If this idea be just, it shews that there is a disposition in the female to come nearer and nearer to the male, at least in the secondary properties; or it may rather be said that the female is later in producing this change than the male is; for it has already been observed that both sexes when young differ not from each other in these respects, but that the male appears to be the one that by degrees separates from the female in its secondary properties.”