COITUS, the act to permit fertilization of the` femaie. In the higher animals this takes place by the intertion of the male organ —.the penis— within the female organ — the vagina. In many lower animals male secretions— sper matozoa— simply mingle with or mechanically come in contact with the female ova. Thus in the fish the ova are deposited in a sort of a crude nest; the male, swimming above the nest, discharges the spermatozoa over them and im pregnation of the egg takes place. In the human animal the process is quite complicated, and since much human happiness is bound up in a •properly performed sexual act a correct lcnowl edge of its physiology should be made avail able. The sexual act may be divided into three stages: (1) desire, (2) erection and excitement and (3) ejaculation or orgasm. In the human being sexual desire is present from the moment of birth although it rarely enters into conscious ness as such and is partially distributed into polymorphous trends to all parts of the body, being inextricably compounded with nutritional desires, with desires for movement, for urina tion, for defecation, etc., etc. In this phase of its evolution the primary instinct for re production has not obtained any conscious di rection, nor found a proper object nor appro priate method. Every sense organ of the body seelcs gratification to satisfy its own needs — these are pursued with much vigor by the child but are rarely directed toward an external object. In many children, perhaps most, geni tal manipulation causes local excitement, but this genital excitement is only a part of the general infantile reaction of reaching out for pleasurable sensations. Nevertheless the chief disturbances which later come to make the sexual act non-satisfying, or perverse in its trends, can be traced back to faulty adjustments of the values of these early infantile poly morphous trends. As one instance of many such faulty adjustments the perversion ;mown as sodomy, in which the rectum is used as a substitute for a vagina, can often be traced back to severe constipations or diarrhceas in infancy, worms or too many enemas, so that the rectum becomes the seat of an exaggerated series of pleasurable excitements, the retention of the memory of which may divert the adult interest away from the physiological goal, the vagina. For the most part, and in the adult whose seas ual adaptation takes a proper course — the in fantile pleasurable trends just spoken of become harmonized, are largely put away by a complex series of repressions and remain latent sources of higher types of creative per fortnance.
Thus in the more healthy types the repro ductive function desire only reappears, and then more consciously, at about the time of puberty. Even then repression is constantly operative and that which is socially under a ban is diverted to other constructive activities. Desire
is now evoked by a series of changes, chief of which are physical, but also conditioned by the presence of the internal secretions of the testes and ovaries. By some it is thought that in the absence of these internal secretions the psy chical associations, which may be denominated the love associations, are unable to bring about sexual excitement and its consequent erection and orgasm; this is true for most cases prob ably, as in eunuchs who have been castrated, but still it is known that it is not invariably so, since some castrated individuals are sex ually very active. Furthermore, there are man individuals, who, with absolutely intact and healthy internal secretions, nevertheless are very impotent from various types of psycho logical blocking. Some are cured of this by proper psychotherapy. Thus all that can be said is that the physical and mental here as well as everywhere else in the body are inter dependent one upon the other. There are innumerable pathways for the psychic stimuli which lead up to sexual desire. No two indi viduals are just alike in this regard. Some-: times the early infantile smelling trends deter mine certain odors as the specific stimuli for the bringing out of desire, with others eye stimuli, others sound stimuli, again touch stim uli, in others urinary or rectal stimuli are the essentials. These are all unconscious associa tions which have been built up from the earliest infantile period. In fact for some even in trauterine stimuli are known to have deter mined certain abnormal trends in this difficult field of the reproductive instinct. Whatever the stimulus or series of stimuli, whether they come from the external world or arise within the body itself, the impressions are carried by certain nerve pathways down the spinal cord to reach the spinal centres, or reflex arc path ways, the integrity of which permits the second essential in the reproduction act, erection. Up to this point male and female act alike — save the influence of the menstrual cycle as a spe cific stimulus to desire in the female, largely missing in the majority of males. There is probably no more difficult subject of investiga tion and one in which so many variations may be found as to what shall determine sexual desire. Within its realm lie all the mysteries of "falling in love,o the "choice of the partner," the happiness and tragedy of human marital relations. Even the structure of society is intimately bound up in this the unconscious sexual life of the child. This is only just beginning to be understood as the preposterous taboo upon the mystery of sex is gradually being lifted and prudery and hypocrisy are giving way, very slowly, to honesty and real enlightenment.