In this volume the terminal phenomena of the sexual process are discussed, before an attempt is finally made, in the concluding volume, to consider the bearings of the psychology of sex on that part of morals which may be called "social hygiene."

Under "Erotic Symbolism" I include practically all the aberrations of the sexual instinct, although some of these have seemed of sufficient importance for separate discussion in previous volumes. It is highly probable that many readers will consider that the name scarcely suffices to cover manifestations so numerous and so varied. The term "sexual equivalents" will seem preferable to some. While, however, it may be fully admitted that these perversions are "sexual equivalents"—or at all events equivalents of the normal sexual impulse—that term is merely a descriptive label which tells us nothing of the phenomena. "Sexual Symbolism" gives us the key to the process, the key that makes all these perversions intelligible. In all of them—very clearly in some, as in shoe-fetichism; more obscurely in others, as in exhibitionism—it has come about by causes congenital, acquired, or both, that some object or class of objects, some act or group of acts, has acquired a dynamic power over the psycho-physical mechanism of the sexual process, deflecting it from its normal adjustment to the whole of a beloved person of the opposite sex. There has been a transmutation of values, and certain objects, certain acts, have acquired an emotional value which for the normal person they do not possess. Such objects and acts are properly, it seems to me, termed symbols, and that term embodies the only justification that in most cases these manifestations can legitimately claim.

"The Mechanism of Detumescence" brings us at last to the final climax for which the earlier and more prolonged stage of tumescence, which has occupied us so often in these Studies, is the elaborate preliminary. "The art of love," a clever woman novelist has written, "is the art of preparation." That "preparation" is, on the physiological side, the production of tumescence, and all courtship is concerned in building up tumescence. But the final conjugation of two individuals in an explosion of detumescence, thus slowly brought about, though it is largely an involuntary act, is still not without its psychological implications and consequences; and it is therefore a matter for regret that so little is yet known about it. The one physiological act in which two individuals are lifted out of all ends that center in self and become the instrument of those higher forces which fashion the species, can never be an act to be slurred over as trivial or unworthy of study.

In the brief study of "The Psychic State in Pregnancy" we at last touch the point at which the whole complex process of sex reaches its goal. A woman with a child in her womb is the everlasting miracle which all the romance of love, all the cunning devices of tumescence and detumescence, have been invented to make manifest. The psychic state of the woman who thus occupies the supreme position which life has to offer cannot fail to be of exceeding interest from many points of view, and not least because the maternal instinct is one of the elements even of love between the sexes. But the psychology of pregnancy is full of involved problems, and here again, as so often in the wide field we have traversed, we stand at the threshold of a door it is not yet given us to pass.

HAVELOCK ELLIS.

Carbis Water, Lelant, Cornwall.