The question of moods and sublimations once raised introduces the problem of the relation of neuroses, nervous disorders without an organic disease basis, and mental abnormalities, to the endocrine system. Obviously, in view of all the influences exerted by the ductless glands upon every organ and function of the body and mind, and their intermediary, the vegetative nervous system, a relation must exist. Observations accumulated, some of which have been referred to in the preceding chapters, prove the complete, though complex, reality of such a deduction.

The history of attitudes toward nerve and mental disorders is a remarkable illustration of the vicissitudes of ignorance playing with words. The Greeks, swayed and dazzled as they were by the magic of words which they discovered, yet never permitted themselves to be fooled by them. As an explanation for the phenomena of hysteria in women, that benign mental disorder par excellence, they had the theory of a wandering about of the womb in the organism as a cause. That provided an image of something material happening as an explanation. With the triumphs of anatomy after the Renaissance, that naÏve view had to be discarded. In its place the humoral theory held sway, with its good humors and its bad humors, and their bilious, lymphatic, nervous and sanguine admixtures. But that, too, went the way of all flesh. During the first half of the nineteenth century, a popular phrase, "nerves," paraphrased by practitioners of medicine as neuroses, then came into vogue as the efficient cause of these troubles. "Nerves" indeed today have filtered everywhere into the common consciousness.

Because of the irritant effects of light, food and social conditions, America has come to swarm with neurotics of every type, especially the sexual. A rich field was created for cults of treatment, which spring up like weeds periodically all over the country. We have seen how the American, Beard, was inspired by the idea that "nerves" represented a loss of tone, a flabbiness, weakness and softness of the nerves, to coin the word neurasthenia. Nerve exhaustion he believed was the cause of the nerve weakness. Weir Mitchell, another American, introduced the rest cure combined with overfeeding as a treatment for it.

An analytical French neurologist, Charcot, was not to be satisfied by words of Latin-Greek derivation. Insisting upon the significance of the individual mental workings of each case, he and his pupil Janet began to unravel a tangle which has led to the present revolution in psychology. For Freud, Jung and Adler took up the story where Janet left off.

Janet elaborated the ideas of a subconscious and an unconscious, a dissociation of the components of the mind, and a splitting of the personality. Lumping the phenomena of amnesia, somnambulism, hypnotism, anesthesia, obsession and hysteria into the grand group of mental dissociations and disintegrations, he achieved a unification never considered possible before him. Suggestion as a mode of cure was also emphasized and elaborated by him to an undreamed-of degree.

Freud, in 1895, studying a case of hysteria with Breuer, had attempted cure by the method of free association, attempting to get the hysteric to pour out her mental life. Not succeeding, and his interest aroused by her continual references to her dreams, he discovered that by means of those dreams he could tap the subconscious and unconscious in regions hitherto inaccessible. For in the dreams, ideas, persons, and experiences appeared that never came upon the stage of the conscious. From that finding he developed the concept of repression, i.e., the relegation of a painful experience into the unconscious, and kept imprisoned there by the censor. Also how there it became the complex, which, like a stage manager, never appeared before the footlights of the conscious, but determined its content just the same by inhibition or stimulation of any character or scene to be enacted upon it.

A complete critique of Freudianism cannot be attempted here. But in relation to the endocrine system as controllers of nerve function in health and disease, a valid criticism can be made. Firstly, the Freudian jargon, its technicalities and explanations, are metaphors. Some may regard them as justifiable descriptions of mental processes. But it certainly can be urged against them that they provide us with no idea concerning what is happening in the cells of the body and brain as explanation for the event, normal or abnormal, supposedly explained. Words like sublimation or transference are figures of speech and nothing else. Secondly, they ignore totally the powers of the vegetative apparatus, the viscera, muscles and secreting glands together, as originators and determiners of the wish and its adventures.

How utterly different, from the point of view of the physiologist, the two explanations are as pictures, can be seen from a single example. The idea of repression, to the Freudian, means the pushing down into the subconscious of some experience. Pushing down is a process controlled by the laws of physics: it involves the concepts of matter and force. Hence, the expression, as a description of a psychic episode, is a metaphor pure and simple. From the standpoint of the process of repression as pictured by the student of the vegetative apparatus, the term signifies a real bottling up of energy. For the repression means actual compression of muscle, the muscle contained in the viscera. And the repression means a real interference with the release of energy, which remains bound up, tugging for room for expression as much as a spring tightly coiled in a box. In the production of that tension an endocrine has often been decisive. The endocrine nature of the individual may decide whether a subconscious, i.e., visceral or vegetative tension, is to come into being, live or die, in the face of a given situation. If thereby, a permanent disturbance of the equilibrium between the components is brought about, a neurosis, expression of an unsatisfied vegetative tension, follows.

It has been hailed as a brand new discovery by those following the latest in psychology that the subconscious and the unconscious constitute a more essential component of the personality than the conscious. As a matter of fact, common practice has recognized the fact, if not the mechanism and its significance, for ages. It is not what people say or do—it is how they say it: that is how the true reactions of personality are recognized instinctively even by animals. Tone and gesture (when not acted or posed) are accepted as symbols and symptoms of states of the inmost sancta sanctorum that words and wit never give entrance to, nay disguise and block. Tone and gesture as revelations of the Inner-Me, the True-Me or Intra-Me if you will, are so potent because they are direct expressions of the vegetative apparatus. The curl of a lip, the flicker of an eye-lash, the twitch of a shoulder are the overflow of energy cramped in the increased intravisceral pressure, determined by increased outflow of endocrine secretion. Wittingly or unwittingly we interpret the little signs as messages from the deepest self, which they truly are.

NERVOUS BREAKDOWNS AND SHELL SHOCK

In civil life, the complex of symptoms Beard jumbled together as neurasthenia, when associated with a loss of self-control, so that the sufferer is incapacitated for the duties of everyday life, has become the popular "nervous breakdown." A sanitarium appears to be one of the necessary components of the condition. It is the last act, the climax of "nerves."

During the War of 1914-1918, thousands of cases of functional disorders of the nervous came to be grouped under "Shell Shock." The psychic phenomena in the wake of concussion of the brain due to explosives suggested the term, and its application to affections of self-control, or dissociations of the personality, with paralysis, blindness, speechlessness, loss of hearing and so on. The War neurosis (including those arising in home service) is still a topical subject because thousands of mentally disabled soldiers are alive.

In view of what has been said concerning the endocrine mechanism of the instincts and the vegetative apparatus, it could be predicted that a number of these nerve casualties of peace and war would be caused by an upset of the equilibrium between the glands of internal secretion. A study of war neuroses by the great Italian student of the endocrines, Pende, confirms this assumption. As emphasized, the internal secretions are like tuning keys, and tighten or loosen the strings of the organism-instrument, the nerves. War for the soldier, or the civilian combatant as well, sets the strings vibrating, and with them the glands controlled by them. Excessive stimulation or depression of an endocrine will disturb the whole chain of hormones, and the vegetative system, and their echoes in the psyche. The nervous disorders of war that have been lumped as shell shock or war shock may be looked upon as uncompensated; airings of the endocrine vegetative mechanism, as dislocations of parts and processes that are reflected outwardly as ailment or disease.

AN ENDOCRINE NEUROSIS

An exquisite example of an endocrine neurosis, that is a disorder of nerves and brain dependent upon an upset of the equilibrium between the internal secretions due to a trying experience, was furnished recently by the reactions of three naval officers lost in the snow wilds of Canada through a balloon adventure. The cases aroused a good deal of interest at the time, and the details were reported by the newspapers as if they were the episodes of a serial mystery story.

The three officers started out late one fine evening from Rockaway Air Station in a balloon for a practice trip. Atmospheric conditions suddenly changed, they became lost in the clouds, and finally landed somewhere in the Canadian wilderness. The commander of the balloon crew, Lieut. A., 23 years old, was the youngest of the three; the oldest, Lieut. B., being 45, and the third man in the thirties, Lieut. C.

According to the testimony given at the Court of Inquiry held afterwards, two hours after they abandoned the balloon and started struggling through the snow, B. became tired and complained of his fatigue. B.'s fatigue increased, and two days later became so great that the party had to stop for an hour and build a fire in order to permit him to rest. However, an hour proved too little: and in another half hour he was falling and fainting.

Letters written by C. to his wife and gotten hold of by reporters declared that B. at this juncture passed into a semi-sane state, in which he accused himself of a number of sins, and volunteered to commit suicide, so that the others would not be burdened by his weakness. Also, that they might use his body to fortify themselves. A. discussed with C. the advisability of taking B.'s knife away from him. Living on their carrier pigeons, they continued on, moved by a desperate hope of finding someone. B. had several fainting spells after drinking water traced by moose tracks.

Luck favored them, and they encountered an Indian who guided them to a place called Moose Factory. Here they wrote the letters home which reached their wives and the daily press before they themselves returned to civilization. A great hue and cry was raised by the newspapers about their plight. Newspaper correspondents vied with each other for the honor of being the first to meet them and get their story.

They arrived at a collection of houses named Mattice. A. and C. proceeded ahead and found instructions for them not to talk. C. went back to B., who was in a shack with the correspondents full of the story of the letters. B. became enraged and struck C. who retained his self-control.

Differences were patched up, and the three returned together to New York. There the medical examination of the three showed that the four days in the wilderness had left its deepest effects upon the physique and mind of B. In a few days he developed an attack of tonsillitis, with fever, and a mental disturbance described by the medical officer as exhaustion psychosis. He believed this condition to be the result of severe exhaustion, prolonged anxiety, worry, and extreme exposure. Extreme restlessness and irritability, confusion of thought and an undefined perplexity, all the prominent symptoms of exhaustion psychosis, making him hyperactive and inclined to acts of violence, were in evidence.

The physique, character and reactions of Lieut. B. are what interest us in the case. The pictures of him published, and the structure of his skull, face and teeth, his hair and other physical traits point to his being an adrenal-centered type, of the unstable variety, so far as his internal secretion make-up is concerned. As we shall see in the next chapter on the different kinds of endocrine personalities, the unstable adrenocentric (convenient name for the class) is characterized by rapid exhaustibility because under conditions of stress and strain, the reserve of the gland is consumed. The adrenal glands, we noted in a preceding chapter, are concerned with the maintenance of muscle and nerve tone in emergencies. They are the glands which, during crises especially, control the production and supply of energy to the various organs and tissues called upon to function to the utmost in emergencies. When the adrenals fail, as they do readily in these labile adrenocentrics, it is as if the adrenals were cut out of the body. And it has been repeatedly shown that extirpation of the adrenals is immediately followed by degeneration and breakdown of the brain cells.

These facts explain the reactions of Lieut. B. The acute call upon his adrenals made by his dangerous situation probably soon exhausted them of their content of reserve secretions. Overwhelming fatigue with loss of muscle tone followed. The changes in the brain caused him to talk as he did in the wilderness. Returned to safety, the news that his reputation was under fire because of C.'s letter brought out another adrenal characteristic: the excessive instinct of pugnacity, easily stimulated, with its emotion of anger and the tendency to violence. What is spoken of as a quick temper is an adrenocentric trait. Returned to New York, an infection, tonsillitis, attacked him. Infections in adrenocentrics use up the content of the adrenals as rapidly as physical exhaustion or emotion. So the tonsillitis, which in another type of individual would have been combatted continuously by the adrenals and so passed by as a mere sore throat, presented him with a high temperature, and the brain disturbance described by the medical officer as exhaustion-psychosis, with again a tendency to violence. In short, the history of his adventure is the history of his adrenals under stress and strain. It illustrates the mechanism of a typical endocrine neurosis.

THE UNCONSCIOUS AND THE VISCERA

In the chapter on the glands of internal secretion as an interlocking directorate, certain generalities were stated as the laws of the government of the organism's life by them in association with the vegetative apparatus. It was put forward as a fundamental revision of the theory, hitherto accepted, of the limitation of mind to the brain cells. We think and feel not alone with the brain, but with our muscles, our viscera, our vegetative nerves, and last but not least our endocrine organs. In short, we think and feel with each and every part of ourselves.

Among these pristine factors determining the content of consciousness, the endocrines are most important, because they alone to start with, of all the other factors, are different in each and every individual. They are what render him unique at birth, even though he looks the counterpart of millions of other babies born at the same time. They constitute his inner destiny. As he grows, the external factors, social experiences, climate, accidents, and disease modify and condition the reactions and complexity of the endocrine system. As these modifications and associations are of the greatest import for the final elaboration of the personality, composing as they do the elements of the unconscious which confers the unique stamp of normal, abnormal, supernormal, or subnormal, it is worth while now to review the most general of the determining laws. Man is an energy phenomenon, both conscious and unconscious, with the energy emanating from the endocrine-vegetative mechanisms. So it becomes possible for us, by their aid, to analyze the conscious, the subconscious and the unconscious with the terms long current in the analyses of physics.

1. Man is an energy machine which, though it is constantly losing energy as a whole; consists of parts constantly accumulating energy (as a result of inherent chemical reactions accelerated by the absorption of food). This process of local accumulation of energy associated with general loss of energy may be observed even in the ameba, in the form of stored reserve food material. Evolution created a system of organs, the viscera, as specialists in energy conservation, utilization or transformation.

For intercommunication and interaction between the viscera two systems were elaborated: a younger system of direct contacts, the nerves, and nerve cells, through which influences could be conducted for the stimulation, acceleration, retardation or inhibition of an energy process in them; and the older, the endocrine gland association, for the production of chemical substances to act as messengers to be sent from one viscus to another, and also to the nerves, through the blood or lymph which bathe all the cells. They could affect only one or certain organs, because by selection only the chosen organ or organs knew the code, as it were. The chemical system is much the older system, and preceded the nerve system by aeons of time. The whole system, viscera, visceral nerves and the endocrines gradually united into a complete autonomous organism within the organism, and as such functions as the vegetative apparatus.

EVOLUTION OF THE ENDOCRINES

2. In the course of evolution, variations occurred in all three components of the apparatus, the viscera, the nerves, and the endocrines. Now variations in the viscera and the nerves are essentially grossly physical and quantitative. That is, there may be a bigger stomach or a smaller stomach, larger nerve fibres or smaller. And as Life always has worked with a large margin of safety, and always played for safety first as regards quantity, these variations have not become of much significance for the history and destiny of the animal.

But variations among the endocrines made a tremendous difference. To have very much thyroid and very little pituitary, much adrenal and not enough parathyroid meant a great deal to the Organism as a whole, as well as to the vegetative apparatus. For states of tension and relaxation, activity and inactivity in the nerves and viscera would be determined by these variations in the ratio between the variants. The vegetative apparatus in its virginity, say in the new-born infant, may be said to have its development primarily determined by the reaction potentials of the endocrine part of it, that is the latent power of each gland to secrete at a minimum or a maximum, and the balance between them.

EDUCATION OF THE VEGETATIVE SYSTEM

3. Training or education involves, beside other effects, a training of the endocrines, and hence of the entire vegetative apparatus, to respond in a particular way to a particular stimulus. Experience is like the introduction of new push-buttons, levers, and wheels into the mechanism. All learning which calls out or arrests the functioning of an instinct, must, from what we have learned of the chemical dynamics of instincts as reactions between hormones, nerves and viscera, affect the vegetative system. When there is a conflict between two or more instincts, between pressures of energy flowing in different directions, there may be compromise and normality, or a grinding of the gears and abnormality.

Where does the brain come in, in all this? As the servant of the vegetative apparatus. To call it the master tissue is manifestly absurd, when it can only be the diplomatic constitutional monarch of the system. It can, in fact, act only as the great central station for associative memory, as only one of the factors implicated in education.

The most powerful educative agents of the vegetative apparatus of a human being are the other humans around him. And they comprise the most powerful of the external effectors of education, for better, for worse. The training and education of the endocrine-vegetative system is the basis of all social rules (Habit, Custom, Convention, Law, Conscience). An unresolved discord, a continued conflict among the parts of the vegetative system, in spite of such education, is the foundation of the unhappiness of the acute or chronic misfits and maladjusted, the neurotic and the psychotic.

THE PHYSICAL BASIS OF THE UNCONSCIOUS

4. Another vastly important law that governs the content of the conscious and the unconscious, and resultant behaviour is the fact that the nerves and nerve cells of the vegetative apparatus, the nerves leading to the viscera and the endocrine glands, like the solar plexus, are affected by stimuli of lower value than those which arouse the brain cells. In the metaphorical language of the old psychology, the threshold value, that is the strength or loudness of stimulus sufficient to make itself felt or heard, is less for the vegetative apparatus than for the brain. So we begin to glimpse why an emotion seems to be experienced before the visceral changes that really preceded it, but pressed their way into consciousness later. This gives us a clue to the unconscious as the more sensitive and deeper part of the mind.

More than that, it supplies us with a physical basis for the unconscious which will explain much of the observed laws of its workings. It provides a reason for the apparent swiftness, spontaneity, and unreasonableness of what is called intuition. And it may show us a source for a good deal of the material of dreams and dream states.

We have said that we think and we remember, not alone with the brain, but with the muscles, the viscera and the endocrines. So do we forget not alone with the brain, but with the muscles, the viscera, the endocrines and their nerves. The utmost importance of muscle attitudes in remembering has been established in the experimental laboratory.

It is one of the great services Freud rendered to psychology (and one, by the way, largely responsible for the acceptance of his doctrines by the disinterested intelligence) that he showed that a species of forgetting is nothing casual, but active and purposeful, a manifestation of the life of the unconscious. However, though his description of the process was correct, he left it to occur in a vacuum. As a matter of fact this forgetting consists in the inhibition of associative memory by a process in the vegetative apparatus, so as to maintain the equilibrium within itself which is reflected in consciousness as comfort.

The unconscious, in short, consists of the buried associations among the parts of the vegetative apparatus and the brain cells. We seem to be much nearer to grasping the nature of the unconscious, when we look upon it as a historical continuum, a compound or emulsion of different and various states of intravisceral pressure and tone, in the vegetative apparatus, dependent upon the balance between the endocrines, as well as upon past experiences of the viscera in the way of stimulation or depression. We forget that which is held down, literally, in the vegetative apparatus. This explanation of forgetting tells, too, why the forgotten (stored in the sub-brain, the endocrine-vegetative system) continually projects itself into and interferes with the regular flow of consciousness, e.g., in slips of the tongue, mistakes of spelling, and so on: because the energy bottled in the vegetative system tends to erupt into the consciousness into which it would ordinarily flow.

In the evolution of the mind, there have been elaborated devices to protect it against the vegetative apparatus. Consciousness, or awareness, must be accepted as a fundamental, primal fact, like protoplasm. Consciousness and protoplasm may be the complementary sides of the same coin. Whatever the truth, the fact stands out that the oldest, deepest, most potent consciousness is that of the traditionally despised lowest organs, the vegetative organs, the heart and lungs, stomach and intestines, the kidneys and the liver, and so on, their nerves, e.g., the solar plexus, and the glands of internal secretion. They invented and elaborated muscle, bone and brain to carry out their will. Evolution has been in the direction of a greater perfection of the methods of carrying out their will. Their consciousness, working upon the growing and multiplying brain cells, has created what we call self-conscious mind.

Mind, reacting upon its creator, has, in a sense, come to dominate them, because it has become the meeting ground of all the energy-influences seething and bubbling in the organism, and so developed into the organ of handling them as a whole, their Integrating-Executive. But just the same and all the time, the underlying consciousness of the viscera and their accessories stand as the powers behind the throne, but as what we have now learned to speak of, in relation to the Mind, as the Unconscious.

PSYCHOPATHOLOGY OF EVERYDAY LIFE

To sum up these relations of the viscera, the endocrines, the unconscious and the mind, it may be stated as a far-reaching generality for the understanding of human life: that character and conduct are expressions of the streams of energy arising in the vegetative apparatus, primarily endocrine determined at birth, and secondarily experience determined after the organism has learned to react as a whole, as consciousness. The result of such a reaction as a whole tends to balance the disturbance of energy, so as to maintain or restore the equilibrium, or sense of harmony and comfort, when consciousness again disappears. This law is an attempt at synthesis of the labors of the psychanalysts, the behaviourists, and the students of the internal secretions (Freud, Jung, Adler, Sherrington, Watson, Von Bechterew, Kempf, Crile, Cannon, Cushing, Fraenkel are the great names of the movement). Most of the details, and all of the quantitative applications of the law still remain to be worked out. But a statement like the following of Cushing, the eminent surgeon-student of the endocrines, that "it is quite probable that the psychopathology of everyday life hinges largely upon the effect of ductless gland discharges upon the nervous system," shows which way the wind is blowing.

In the face of these conceptions the position of the psychanalyst as a practical therapeutist becomes clearer, and the causes of his failure when he fails. In the first place, he deals with psychic results as processes, and ignores the physiology of their production. Since a true cure of the neurosis, what he is after, is impossible without a removal of the cause, a disturbance in the vegetative apparatus, he cannot succeed where an automatic adjustment among the viscera does not follow his probings and ferretings of the unconscious. In the second place, he disregards the existence of a soil for the planting of the malign complexes in the individual in whom they grow and flourish. That soil is composed in part of the endocrine relations within the vegetative apparatus. And as we can often attack that soil more effectively and radically from the endocrine end than from the experience end (e.g., repressed episodes) we may transform the soil and make it barren rock for morbid complexes, at any rate. The concept of the endocrine-vegetative apparatus as the determinant of normal and abnormal behaviour, emotional reactions and disturbances of power should in time cause even the most fanatic of the psychanalysts to recognize the functional basis of the mental acrostics they are so fond of dissecting.

NATURAL ABILITY

Another achievement of the psychanalysts is the recognition of the influence of organic and functional inferiorities of the individual upon the history of his personality. Gross organ inferiorities are those which are definite handicaps in the struggle for success in society, such as heart disease. Such handicaps, however, are limited to relatively few of a population. The raison d'Être of the greater number of minor mental inefficiencies the psychanalyst puts down to handicaps in the unconscious. Again he mistakes figurative imagery for explanations. The conception of endocrine diversity in the make-up supplies us with the rationale of the vast majority of organic and functional defects and inferiorities, in short, subnormalities of any group, large or small.

Moreover, how would the psychanalyst explain the occurrence and influence of organic and functional superiorities and their tremendous influence upon the individual and society? We live in a generation which has acquired a flair for the pathologic. Undoubtedly it is a soul-sick generation, and its interest in sickness of the mind is only natural. Just the same, whatever advances, improvements, progress, have been made (and certainly a number of the changes in his environment, external and internal, must be admitted to be changes for the better) have been made, not by natural disability, but by natural ability. What is the physiology of natural ability?

The finest study of natural ability that has as yet been composed is Francis Galton's on Hereditary Genius. It also remains the best study of the natural conditions of success. He showed that of the type of man he classed as "illustrious" there occurred about one in a million, and of the type "eminent" about two hundred and fifty in a million. Of the qualities which determine natural ability of this kind, he selected inherent capacity, zeal, and perseverance as the three prerequisites. And he states that "If a man is gifted with vast intellectual ability, eagerness to work, and power of working, I cannot comprehend how such a man should be suppressed." "Such men (those who have gained great reputations) biographies show to be haunted and driven by an incessant, instinctive craving for intellectual work." "They … work … to satisfy a natural craving for brain work." "It is very unlikely that any conjunction of circumstances should supply a stimulus to brain work commensurate with what these men carry in their own constitutions."

What is this inherent craving for brain work? What is this zeal? And what is power of endurance and perseverance, the quality of stamina? How are they to be interpreted in terms of the internal secretions?

In view of what has been said of the ante-pituitary as the gland of intellectuality, studies of intellectually gifted people having shown well functioning large pituitaries, and of mental defectives in a certain number of cases a small limited pituitary, it is justifiable to regard the factor of inherent capacity as a function of the ante-pituitary. The factor of zeal or enthusiasm points to the thyroid. Markedly enthusiastic types are thyroid dominant types. Vigor as a third factor, the ability to stand stress and strain of continued effort is dependent upon good adrenal and interstitial cell function. So we may say that craving and capacity for brain work plus ardor plus perseverance in its pursuit, the triplicate of natural ability, are the reflections in conduct and character of balanced and sufficient ante-pituitary, thyroid, and adrenal-interstitial contributions in the chemical formula of the personality. In the chapter on historic personages analyzed from the endocrine viewpoint, we shall see that some of the most eminent and illustrious people of history have been pituitary-centered.

MENTAL DEFICIENCY

Natural ability grows in an endocrine soil of a particular kind, perhaps affected by the internal secretions much as natural soil is by fertilizers like phosphates or nitrates. Increased production follows increased fertilization. Natural disability must vary similarly with a perversion or improper mixture, deficiency or absence of the hormones that combine in natural ability.

It is assumed as a matter of course that the brain itself is there, which, to carry out our analogy, means that the crude soil or earth is there. Sufficient quantity and adequate quality of nerve tissue must be regarded as prerequisite. If the brain has been damaged in any way during development or birth, if it has been smashed up in any way, or if it has failed to evolve the minimum number of healthy nerve cells, the endocrine influence becomes negligible. It is like attempting to insert a key into a door which has no lock.

It is among the specimens of normality of the brain cells that we may look for our examples of endocrine mental deficiency. Included are all sorts of examples of feeble-mindedness varying from the moron to the imbecile and idiot, arrested brain life. The cretin is the classic type of mental deficiency due to endocrine insufficiency, curable or improvable by the proper handling.

Insanity, degeneration of the normal brain life, may be caused by an upset of the endocrine balance. Among the commonest manifestations of insanity are excitements and depressions, apathies and manias, hallucinations, delusions and obsessions, all of which are reproducible under known conditions of internal secretion excess or failure. Alternating states of mania and depression are caused in some instances by extreme hyperthyroidism. The critical periods of life, when a profound revolution is overturning the endocrine equilibrium, puberty, pregnancy, and the menopause, are the periods of most frequent occurrence of insanity, when mental instability reveals endocrine instability (Dementia praecox, pregnancy psychosis, menopause neurosis). Actual insanity need not be the only manifestation. By far the greater number of mental disturbances due to aberrations of the internal secretions never see an asylum or a doctor. They live more or less close to the borderline of insanity as persons who have spells, eccentricities and peculiarities, hysteria, tics or just "nervousness."

About two-thirds of mental deficiency is definitely inherited, about one-third acquired. It is the opinion of a number of psychologists that it is inherited as what the Mendelians call a recessive, that is as a trait which will be overshadowed, if there is admixture of normal mentality, but will crop up by breeding with another mental defective. What we know of the endocrine factors in heredity leads us to suppose that it is the mating of one marked endocrine insufficiency with another that is often responsible for the inherited tendency to feeble-mindedness and insanity. The effect of the hormone system upon the vegetative apparatus may create the more obscure insanities and quasi-insanities. The direct action of the internal secretions upon the brain cells, producing a sort of hair trigger situation within them, may cause the explosive discharges from them which appear as overpowering impulses or uncontrollable conduct. The waves of feeling which precede them are unquestionably endocrine determined. The wave of fear a cat experiences upon seeing a dog is accompanied and indeed preceded by an increase of the amount of adrenalin in the blood. The picture of fright, as observed in a so-called normal person, staring eyes, trembling hands, dry lips and mouth, corresponds to the portrait of the appearance in hyperthyroidism. In persons afflicted with uncontrollable impulses, the inhibiting hormones may not be present in sufficient quantity.

Feeble-mindedness, ranging from stupidity to imbecility, may also be a direct effect of insufficient endocrine supply to the brain cells. When there is not enough of the thyroid secretion in the blood, the tissue between the cells in the brain become clogged and thickened, so that a gross barrier to the passage of the nerve impulses is created. We have here an illustration of internal secretion lack actually producing gross changes in the brain. But without a doubt, most endocrine influences upon the brain, at work every minute and second of its life, are the subtle ones of molecular chemistry and atomic energetics. We know that such mental qualities as irritability and stupidity, fatigability, and the power to recover quickly or slowly from fatigue, sexual potency and impotence, apathy and enthusiasm are endocrine qualities. We know also that the thyroid dominant tends to be irritable and excitable, the pituitary deficient to be placid and gentle, the adrenal dominant to be assertive and pugnacious, the thymus-centered to be childish and easy-go-lucky and the gonad deficient to be secretive and shy. This brings us to the relation of the internal secretions to the type of personality as a whole.