experienced de novo, as far as the empirical ego of the animal is concerned, when it recurs, and familiarity towards it is thereby rendered impossible. With the passage of each unit of time after the incidence of the experience there is a fading of the associated emotionalism and an ultimate disappearance, unless, owing to imperfect performance the initial experience recurs. In such circumstances the emotion concerned also recurs in maximum intensity.

In the event of performance being efficient the animal, subjectively, returns to the status in quo, and to all outward appearances it is exactly as it was before the experience occurred.

The degree of the amnesia developed would of necessity be inversely proportional to conscious attention at the time obtaining; in proportion with this degree the animal under the influence of such an emotion is dazed or confused. The psychical 'energy' developed in such an environment is, so to speak, devoted to vehement somatic response at the expense of attentive consciousness, and, given that a similar state of affairs again arises, a similar somatic response recurs. Not only however does such response recur, but it recurs all the more readily and, in the course of time it is capable of recurring in apparently undiminished efficiency with progressive lessening of the emotional intensity necessarily operative. That is, the animal is altered by experience in the direction of the development of habit action. This mechanism for the formation of habitual action is in all probability of the greatest utility to the animal; it enables it to modify its behaviour in surroundings in which at one time or another a dangerous situation has occurred with a minimum of conscious attention and, therefore, with a maximum of somatic efficiency. Given that a terrifying experience again occurs in such a situation, then the behaviour that proved efficient on a former occasion is reinstituted with increased readiness.

On the other hand, given that an incident associated with an emotional tone be not subjected to amnesia, the ultimate exhaustion of that tone leads to a de-emotionalised attitude of the animal to the incident; the latter becomes familiarised to the former. In the case of the emotion of parental tenderness we find that the more elaborate the precedent somatic alterations the more lengthy is the duration of the emotion likely to be; it is reasonable to associate the specific conation with these changes. In the absence of a specific amnesia there is nothing in the psychology of the animal to prevent conscious memorisation of the incident provided the animal has the necessary anatomical associational mechanism available, but in the case of such animals as the cat for example

it is difficult to assume this conscious or pictorial memorisation for its kittens in their absence, and much of the characteristic behaviour of the maternal animal is in all probability dependent upon physiological conditions specific to maternity, and the kittens to a certain extent may be looked upon as ectopic parts of the mother. (The replacement mentioned above of a kitten of a previous litter for those of the recent which had been destroyed is suggestive in this respect; the older animal made no distinction between the immature and comparatively mature kittens as far as behaviour was concerned. The emotional tone apparently corresponded rather with the somatic state of the mother than with the development of the offspring.)

In the event of the animal again developing the emotion, then the appropriate behaviour is all the more readily performed and to this extent perhaps such behaviour may be considered habitual. But it is not so in the true sense; in the sense, that is, of such behaviour being performed with uniform efficiency with a decreasing emotional tone intensity. Among the non-human animals it is found that with the fading of the emotion there is a corresponding fading away of the characteristic behaviour.

The absence of amnesia in such tones is accompanied by an absence of psychical confusion; there is nothing to prevent a high degree of attention in the case of animals manifesting the emotion of tenderness.

The difference in the re-inducibility of emotions of the two orders does not appear to depend so much on psychical dissociation as upon the presence or absence of specific body changes necessary for appropriate conation. The possibility of the same experience, however, uniformly re-inducing it in maximum intensity, is to be associated with this process, in the manner discussed above. The behaviour of an animal under the influence of an emotional tone therefore would appear, inter alia, to vary with two factors; the necessity or otherwise of preceding and succeeding specific body alterations on the one hand, and the presence or absence of psychical dissociation on the other. We may I think express this in a simpler form and say that the process of psychical dissociation is an essential associate of an emotional incidence in the non-human animals, unless such incidence is necessarily associated with preceding and succeeding gross anatomical alterations.

Arising out of the above, it would appear that pictorial memorisation among the lower animals, if it occur at all, is exceedingly incomplete, and can only occur in the sphere of those emotional tones which are not associated with the process of psychical dissociation. Experiences which

give rise to tones of the other order, being subjected to a specific amnesia, cannot be memorised; the behaviour of the animal in relation to such experiences shows a predisposition to habitual action.

The human differs from the non-human animal in that he is, normally, able to recall in pictorial memory experiences which were primarily associated with a terrifying emotional tone. An inquisition into the behaviour of the human under the influence of such a tone, as compared with one of the lower animals, reveals as a prominent difference the fact that the former is able to 'control' his behaviour; he does not necessarily give way to headlong flight or to blind pugnacity. The ability to control emotional tones in relation to their appropriate conative activities would appear to be almost exclusively a human attribute; the human race as constituted to-day shows a wide variation in the degree of control possessed by different communities and different individuals, a fact which emphasises the specificity of such control to the human being, and its comparatively recent genesis.

Anatomically the important differentiating feature between the human and the non-human animal is the very great increase in the former of the cerebral association-dispositions. It is of interest to realise that in the human we have this extended range of association-dispositions, the possibility of emotional control and the ability to memorise events experienced in a terrifying atmosphere. This amounts to saying that under such circumstances we do not have the operation of psychical dissociation for such experiences, and psychically this would seem to be the fundamental difference between the mental processes of the human and the non-human animal.

I would suggest that the chief factor in the human which militates against the operation of psychical dissociation is emotional control; conversely, that the defective development of such control in the human enables the process of psychical dissociation to be operative. Expressing this in other words we may say that the obtrusive manifestation of psychical dissociation in the human is an approach to the non-human psychology; clinical symptoms arising out of such manifestation are indications of a psychical retrogression.

The clinical condition which is characterised by the undue operation of psychical dissociation is hysteria; hysteria therefore may be considered as a retrograde manifestation; one in which the human approaches abnormally the non-human psychology. Furthermore, in that emotional control is acquired by the human during his early years and is absent or nearly so in the infant and young child, dissociation is to be expected

normally in the period of immaturity; the psychical processes of infants and young children are essentially of the hysterical order and differ from hysteria only in that they are normal to this stage of development. As they grow older their emotional control develops and they show no more of their 'hysterical' heritage than is normal to the generality of mankind. If however, through faulty environment of upbringing, their control does not develop as it should, then clinical hysteria is apparent when the environment of upbringing gives way to that of the community in which they have to live and work. But, even so, as such people do grow older, their control does increase, and their hysterical manifestations disappear, unless they are perpetuated as habits through persistent maltreatment.

It should be remembered that we all of us have developed out of this atmosphere of infantile uncontrol of our emotional tones and the psychical dissociation that goes with such lack of control; many useful elements of behaviour in normal man may be traced to this phase of his life. It is only when emotional control and psychical dissociation are allowed to persist abnormally that the subsequent behaviour becomes of clinical interest.

The function of emotional control, as pointed out above, is a recent acquisition of the human being and, as is often the case with such acquirements, its development may be irregular and unbalanced as far as emotional tones of the two orders are concerned. An important accompaniment of emotional control is the divorcement of a strongly felt emotion from the conative activity which through the ages has been associated with it. This separation in certain cases may be carried too far, and disordered functioning of the nervous system may result. The most obvious example of this was to be seen during the war in the form of the 'terror neurosis.' Here, as a result of the outrageous environment of danger, a number of apparently healthy men, fully conscious of the extremity of that danger, exerted their control and did not manifest the phylogenetically determined response of removing themselves out of the danger zones. In the course of time the strain on their control became too great and they broke down; their symptomatology manifesting in a bastard form the conation which they had denied themselves. This took the form of muscle activity in the form of tremors; dilatation of the pupils; pallor; sweating and so forth; and the experience of crude terror when their residual control was still further decreased during the impaired consciousness of sleep (terror dreaming). Owing to the absolute value of the environment at this time, all men tended to show signs of this disturbance after they had endured for a certain time; some breaking down sooner than others. In civil life this neurosis is uncommon, though it

does occur, and the features emphasised above are always to be recognised, though rarely in the same degree of intensity as was seen during the war years. Such patients are tremulous; they are confused, as indicated by their inability to concentrate and to memorise; they experience characteristic terror dreams and in their history there is always the factor of life among danger, or what they imagine to be danger.

In such cases we have the converse of the retrograde neuroses; instead of developing amnesia for terrifying experiences we have for a time a concentration of control with its ultimate straining and final failure. In that the acquisition of control is associated with evolution disorders of this class-'instinct-distortion' neuroses-should be considered as being progressive; separate and distinct from the regressive or hysterical disabilities.

The condition just described is associated with maltreatment of an emotional tone of the fear order; it is of interest to notice that a similar distortion directed to the emotions associated with reproduction also gives rise to morbid states. But whereas the former is as a rule sufficiently dramatic to bring the sufferer under medical attention, in the case of the latter this is not so. The fact that such a distortion does produce abnormalities of behaviour is in the majority of cases only to be recognised when the patient comes for treatment in a later stage of his condition, when the pure instinct-distortion neurosis has passed into a later and a different group.

A careful examination into the history of such cases however will often reveal the state of affairs represented by the following example.

The patient, a female aged 39, complains of severe pressure pain over the vertex, depression, irritability and sleeplessness. The onset of her condition was two or three years ago; she became unaccountably moody and irritable but at that time had no pain. She slept badly and her dreams troubled her. These were of the type which may be christened 'dreams of unsatisfied desire' and which, occurring infrequently, are common to the generality of mankind. In them the patient is always endeavouring to do something which is unattainable; attempting to overtake something, the feet being glued to the ground; doing some impossible task against time; trying to climb a mountain, the summit of which always recedes. The important feature of these dreams, in assessing their clinical significance, is that they waken the patient, and the state on waking is not so much one of terror as of utter misery; misery to the point of weeping. Furthermore, such dreams to have clinical significance occur frequently.