We cannot speak so positively as to the truth of this in the case of the reproductive glands in women, the ovaries, because alike in the human female and in the females of the lower animals oöphorectomy is less commonly performed than is castration in the male. The literature of our subject contains few references to this matter. What little information we do possess, derived in part from travellers who have had opportunities for observation in extra-European countries, and in part from students of animal life, leads to the same conclusion as in the case of males, namely, that long before the age commonly regarded as the commencement of sexual maturity, important changes are going on in the reproductive glands.
No detailed discussion can be attempted here of the other observations there may be on record to show the existence of such sexual processes during childhood. We may merely refer, for example, to the results of the removal of one testicle before the commencement of puberty; this is followed by a compensatory hypertrophy of the other testicle—whereas removal of one testicle after the attainment of sexual maturity does not lead to any such hypertrophy of the remaining testicle, or if so, only in comparatively slight degree.
Although from the facts just stated it appears that, alike in human beings and in the lower animals, before the formation of the specific germ-cells and sperm-cells has begun in the reproductive glands of the respective sexes important processes take place in these glands, it still remains obscure what is the nature of these processes, and in what manner they influence the organism. One question complicating this problem, and one which is to-day frequently discussed, is the extent of the influence exercised by the reproductive glands on the development of the secondary sexual characters. I can here do little more than state the difficulty. Whereas it was formerly assumed that the reproductive glands exercised a direct determining influence in this direction, more recently another view has been put forward, among others by Halban.[47] According to this theory, the stimulus proceeding from the glands is protective merely, not formative, nor directly stimulating the growth of organs. In the fertilised ovum, it is supposed, the rudiment of sex already exists, likewise the rudiment of the reproductive gland, and the rudiments of the appropriate sexual characters. That is to say, the development of the secondary sexual characters is not determined by the presence of the reproductive gland; but the sex of the reproductive gland and the associated sexual characters are already determined by some common cause at the moment of fertilisation. But this theoretical controversy has no very important bearing on the problem with which we are especially concerned; and the influence of the reproductive gland upon the development of the secondary sexual characters is admitted as fully by Halban as it is by other writers, the only difference between the two views lying in the dispute whether the influence of the glands is of a formative or a protective nature. The influence exercised by the reproductive glands on the development of the secondary sexual characters can be adequately discussed, even though the precise way in which that influence is exerted remains in dispute.
As to the general nature of the influence, two chief theories have to be considered, viz., the nervous theory and the chemical theory. According to the former, we must assume that a stimulus originates in the reproductive glands, the testicles in the male, and the ovaries in the female, and that these glands excite a kind of reflex action—that is, that the stimulus passes to the central nervous system, and thence is "reflected" to the periphery, where it promotes, either the growth of particular parts of the body, e.g. the beard, or the development of definite properties in certain organs, e.g. the characteristics of the male larynx or of the female mamma. It is possible that the reflected impulse stimulates trophic nerves. But it may be that in cases of early castration the state of affairs is similar to that which obtains when from earliest infancy one of the sense organs is wanting, as a result of which the corresponding portions of the central nervous system are found to undergo atrophy.[48] On this assumption, the manifest arrest of the development of certain organs which results from castration is to be regarded as the sequel of a partial atrophy of certain portions of the brain. Of late, however, the chemical theory, that the results of castration are dependent on the lack of the internal secretion of the excised glands, has gained ground at the expense of the nervous theory. The reason for this change of view is that much which was unsuspected in former years has recently been learned about the chemical activities of other glands. It suffices to allude to the function of the thyroid body. According to this chemical theory, chemical substances are prepared in the reproductive glands, and these substances exert a specific influence in promoting the development of the secondary sexual characters. The same theory has been invoked to account for the alleged ill effects of sexual abstinence, it being suggested that the reabsorption of glandular products properly destined for excretion may give rise to toxic effects.[49] If it be assumed that the testicles can secrete substances upon the influence of which the development of the secondary sexual characters depends, it is obvious that these substances have nothing to do with the spermatozoa, inasmuch as the testicles exert the influence under consideration at an age at which the formation of spermatozoa has not yet begun. The substances that act in this way must be of a different kind. As was pointed out earlier in this book (p. 19), recent researches have shown that the testicles possess a twofold activity; and some French physicians even go so far as to say that the testicle is not a single gland, but two glands. They distinguish between the gland that prepares the spermatozoa and the interstitial gland.[50] Whilst the formation of spermatozoa subserves the generative act, the function of the interstitial gland is to prepare substances which pass into the lymph or blood-stream, and give rise to the development of the secondary sexual characters. Thus, the effects of castration are due, on this theory, not to the absence of the formation of spermatozoa, but to the absence of the products of the interstitial glands. French investigators consider that the assumption that such an interstitial gland exists is justified by the results of experimental work.
Whichever theory we accept, the chemical or the nervous, both theories harmonise equally with the fact that in boys, before the formation of spermatozoa begins, processes occur in the testicles which powerfully influence the organism. Thus, we learn also from a study of the results of castration how active is the sexual life even in childhood, since thus early in life influences proceed from the reproductive glands whereby the development of the secondary sexual characters is markedly affected.
The principal sexual processes occurring in childhood have now been described. Although we have been forced to admit the fact that in the child sexual processes are much more extensive than has commonly been believed, we must, on the other hand, guard ourselves against the exaggerations of those who interpret everything in sexual terms. In the chapter on diagnosis it will be necessary to refer to these exaggerations once again.
As a rule, of course, the manifestations of the sexual life of the child increase from year to year, although not always by continuous gradations. Thus, in consequence of misdirection, sexual manifestations may arise in the child, and then, if these evil communications are cut off, such manifestations may cease. But, altogether apart from deliberate seduction, we may observe periods of more rapid and periods of less rapid sexual development, the causes of which may remain obscure. Individual cases vary to such an extent, that it is impossible to lay down a rule to which there are no exceptions. This applies equally to both components of the sexual impulse, to the phenomena of detumescence as well as to those of contrectation.
But although as we have seen, the development of the sexual life is not always by regular progression, yet on the whole the increasing intensity of sexual manifestations from the years of childhood to the termination of the period of the puberal development cannot be denied. Especially extensive are the changes occurring at the end of the second period of childhood. At this period we note more particularly the development of the outward signs of sexual maturity. In the boy, we observe the growth of the beard and the pubic hair, and a more rapid enlargement of the testicles and the other organs of reproduction. In the girl, the breasts and the pelvis assume the adult female type, and ovulation and menstruation begin. During this period, also, the mental changes are extremely marked, even though in many cases these changes may have begun considerably earlier. The internal organic changes make themselves felt also in the sphere of action. The years of adolescence in the male are characterised by an impulse to travel, to adventures, but in addition to all kinds of ideal efforts and to religious activity. The loftiest ethical ideas alternate with a self-conscious bumptiousness. A change of disposition manifests itself which is sharply contrasted with the behaviour at an earlier and a subsequent age. This is no less true of the girl. That which formerly was no more than a vague indication, now becomes a manifest quality. More and more does the feminine mode of feeling display itself. The "tom-boyishness" so often seen in girls during the second period of childhood disappears. The former tomboy has become one[51]—
"In whose orbs a shadow lies Like the dusk in evening skies,"
and we see her—