It is, moreover, established beyond dispute that in certain cases, in consequence of an inborn predisposition, contrary sexual inclinations make their appearance, and that these represent a divergency from the proper sexual characters. It is with these mental sexual differential characters just as it is with the physical secondary sexual characters, any of which may, on occasion, make their appearance in the wrong sex, or may be wanting in the right one. We know that there exist women with beards, masculine larynges, and a masculine type of thorax; and, on the other hand, men with feminine mammae, feminine larynges, and a feminine type of pelvis. Because we meet with such atypical instances, we are not therefore justified in inferring that it is by a mere arbitrary sport of nature that in the woman a great mammary development is normally associated with the development of the ovaries, and that in man the growth of the beard is associated with the development of the testicles. But just as in these respects there are certain exceptions, whose origin we are not always in a position to explain, so also are there exceptional sexual associations in respect of the secondary psychical sexual characters. Thus it comes to pass that many women exhibit masculine tendencies, and many men exhibit feminine tendencies. Unquestionably, the fact that psychical qualities, just as much as physical characters, may occasionally make their appearance in the wrong sex, does not invalidate the general truth of the statement that sexually differentiated psychical tendencies are inborn. Occasionally, indeed, even in late childhood, this psychical differentiation is still but little marked. We must also bear in mind the fact that in many instances the bodily development of the girl--apart, of course, from the actual reproductive organs--differs but little, even during the second period of childhood, from that of the boy; and that in such cases the specific differentiation makes its first appearance later than is usual. We find boys also who have entered upon the period of youth (see p. 1) without exhibiting any trace of downy growth upon the upper lip or the chin; in some, the first definite growth of hair on the face may not occur until several years later. I remember also that I have seen boys in whom during the period of puberal development an enlargement of the mammae took place, going so far that it was possible by pressure on the glands to expel fluid from the mammillary ducts; at a more advanced age, however, this mammary growth was arrested, and subsequently atrophy ensued. But all these observations notwithstanding, the fact remains well established that even in childhood notable sexual differences make their appearance. Other observations, too, confirm this notion of sexual differentiation--for example, pathological experiences.