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of the body。 If the environmental impacts are repeated with such frequency that the brain…cells have no time for restoration between them； the energy of the cells becomes exhausted and a condition of shock results。 Every action of the body may thus be analyzed into a stimulation of ceptors； a consequent discharge of brain…cell energy； and a final adaptive activation of the appropriate part。 Walking； running； and their modifications constitute an adaptation of wonderful perfection； for； as Sherrington has shown； the adaptation of locomotion consists of a series of reflexes ceptors in the joints； in the limb； and in the foot being stimulated by variations in pressure。
As we have shown； the bene… and nociceptors orientate man to all forms of physical contactthe former GUIDE HIM TO the acquisition of food and to sexual contact； the latter DIRECT HIM FROM contacts of a harmful nature。 The distance ceptors； on the other hand； adapt man to his distant environment by means of communication through unseen forcesethereal vibrations produce sight； air waves produce sound； microscopic particles of matter produce smell。 The advantage of the distance ceptors is that they allow time for orientation； and because of this great advantage the majority of man's actions are responses to their adequate stimuli。 As Sherrington has stated； the greater part of the brain has been developed by means of stimuli received through the special senses； especially through the light ceptors； the optic nerves。
We have just stated that by means of the distance ceptors animals and man orientate themselves to their distant environment。 As a result of the stimulation of the special senses chase and escape are effected； fight is conducted； food is secured； and mates are found。 It is obvious； therefore； that the distance ceptors are the primary cause of continuous and exhausting expenditures of energy。 On the other hand； stimuli applied to contact ceptors lead to short； quick discharges of nervous energy。 The child puts his hand in the fire and there is an immediate and complete response to the injuring contact； he sees a pot of jam on the pantry shelf and a long train of continued activities are set in motion； leading to the acquisition of the desired object。
The contact ceptors do not at all promote the expenditure of energy in the chase or in fight； in the search for food or for mates。 Since the distance ceptors control these activities； one would expect to find that they control also those organs whose function is the production of energizing internal secretions。 Over these organsthe thyroid； the adrenals； the hypophysisthe contact ceptors have no control。 Prolonged laboratory experimentation seems to prove this postulate。 According to our observations； no amount of physical trauma inflicted upon animals will cause hyperthyroidism or increased adrenalin in the blood； while fear and rage do produce hyperthyroidism and increased adrenalin （Fig。 44） （Cannon）。 This is a statement of far…reaching importance and is the key to an explanation of many chronic diseases diseases which are associated with the intense stimulation of the distance ceptors in human relations。
Stimuli of the contact ceptors differ from stimuli of the distance ceptors in still another important particular。 The adequacy of stimuli of the contact ceptors depends upon their number and intensity； while the adequacy of the stimuli of the distance ceptors depends upon the EXPERIENCE of the species and of the individual。 That is； according to phylogeny and ontogeny this or that sound； this or that smell； this or that sight； through association recapitulates the experience of the species and of the individual awakens the phylogenetic and ontogenetic memory。 In other words； sights； sounds； and odors are symbols which awaken phylogenetic association。 If a species has become adapted to make a specific response to a certain object； then that response will occur automatically in an individual of that species when he hears； sees； or smells that object。 Suppose； for example； that the shadow of a hawk were to fall simultaneously on the eyes of a bird； a rabbit； a cow； and a boy。 That shadow would at once activate the rabbit and the bird to an endeavor to escape； each in a specific manner according to its phylogenetic adaptation； the cow would be indifferent and neutral； while the boy； according to his personal experience or ontogeny； might remain neutral； might watch the flight of the hawk with interest or might try to shoot it。
Each phylogenetic and each ontogenetic experience by an indirect method develops its own mechanism of adaptation in the brain； and the brain threshold is raised or lowered to stimuli by the strength and frequency of repetition of the experience。 Thus through the innumerable symbols supplied by environment the distance ceptors drive this or that animal according to the type of brain pattern and the particular state of threshold which has been developed in that animal by its phylogenetic and ontogenetic experiences。 The brain pattern depends upon his phylogeny； the state of threshold upon his ontogeny。 Each BRAIN PATTERN is created by some particular element in the environment to which an adaptation has been made for the good of the species。 The _*state of threshold_ depends upon the effect made upon the individual by his personal contacts with that particular element in his environment。 The presence of that element produces in the individual an associative recall of the adaptation of his speciesthat is； the brain pattern developed by his phylogeny becomes energized to make a specific response。 The intensity of the response depends upon the state of threshold that is； upon the associative recall of the individual's own experiencehis ontogeny。
If the full history of the species and of the individual could be known in every detail； then every detail of that individual's conduct in health and disease could be predicted。 Reaction to environment is the basis of conduct； of moral standards； of manners and conventions； of work and play； of love and hate； of protection and murder； of governing and being governed； in fact； of all the reactions between human beingsof the entire web of life。 To quote Sherrington once more： 〃Environment drives the brain； the brain drives the various organs of the body。〃
By what means are these adaptations made？ What is the mechanism through which adequate responses are made to the stimuli received by the ceptors？ We postulate that in the brain there are innumerable patterns each the mechanism for the performance of a single kind of action； and that the brain…cells supply the energyelectric or otherwise by which the act is performed； that the energy stored in the brain…cells is in some unknown manner released by the force which activates the brain pattern； and that through an unknown property of these brain patterns each stimulus causes such a change that the next stimulus of the same kind passes with greater facility。
Each separate motor action presumably has its own mechanism brain patternwhich is activated by but one ceptor and by that ceptor only when physical force of a certain intensity and rate of motion is applied。 This is true bot