In different locales of the vegetative apparatus, as indeed of the body in general, the directorate seems to be handed over to a committee of control, generally made up of two members working in opposing directions.  Such a division of power in the general directorate is analogous to the small holding corporations which divide functions in, for example, the United States Steel Corporation.  The relative ratios of tonus in these smaller internal secretion balances are of the utmost significance as causes of differences in the vegetative apparatus, which are the basis of differences in structure, power, and character between individuals.

THE GENERAL LAWS OF THE DIRECTORATE

Our knowledge of the glands of internal secretions as an interlocking directorate presiding over all the functions of the organism is still exceedingly meagre.  As yet, we seem to be knocking at the portals of the chemistry of the imponderable.  There are holes in the bronze doors, and we glimpse the unfathomable distances of unexplored regions.  But we do see something, and we do glimpse a beginning.  Already the outlines of a differential anatomy, and a different physiology and a differential psychology, which will explain to us the unique in the constitution, the temperament and character of an individual, emerge.  It is worth while, before proceeding to the details, so valuable to a society which would become rational, to summarize the general principles emerging, expressing the directing powers of the ductless glands over the individual. They may be regarded as the present postulates of a new science of the whys and wherefores separating and setting apart, as so recognizably distinct, those peregrinating chemical mixtures:  men and women.

1.  The life of every individual, in every stage, is dominated largely by his glands of internal secretion.  That is, they, as a complex internal messenger and director system, control organ and function, conduct and character.  The orderliness of human life, in the sequential march of its episodes, crises, successes and failures, depends, to a large extent, upon their interactions with each other and with the environment.

2.  One or several of the glands possesses a controlling or superior influence above that of the others in the physiology of the individual and so becomes the central gland of his life, its dominant, indeed, so far as it casts a deciding vote or veto, in its everyday existence and incidents as well as in its high points, the climaxes and emergencies.

3.  These glandular preponderances are at the basis of personality, creating genius and dullard, weakling and giant, Cavalier and Puritan.  All human traits may be analyzed in terms of them because they are expressions of them.

4.  Specific types of personality may be directly associated with particular glandular prominences, so that we have the thyroid-centered types, the pituitary-centered types, the adrenal-centered types, etc.  These are the classic Three, the prototypes in their purity most easily described and recognized.