MUSCLES

It would seem, at first sight, that organs like muscles, mechanical instruments for the manipulation of the organism in space, would be more or less independent of the subtler processes of internal chemistry of the blood and tissues.  But no assumption would be more beside the mark.  Just as much as the bones and viscera, the teeth and the hair, they show grossly how they are being influenced by all the endocrine glands.  So thyroid types generally have a skeleton sparsely covered with a muscular mantle.  Pituitary types have large well-developed muscles.  The pineal gland has some definite relation to muscle chemistry not yet probed.  Thus, it has been shown that when the pineal has been completely destroyed prematurely by lime deposits in it, there is concomitant a wasting of muscles in places.  This waste is sometimes replaced by fat.  Pictures and images in wood and stone of these muscle freaks dating from the fifteenth, sixteenth, and seventeenth century are in existence.  Then there is the extraordinary fatigability of the muscles which occurs in the thymus types, who nevertheless have large well-rounded muscles, a paradox of contradiction between anatomy and physiology.  Such a type, for instance, may be picked out by a football coach for an important position in a line-up, simply on the tremendous impressiveness of the muscle make-up, only to see him bowled over and out in the first scrimmage.  The tone of muscles, the quality of resisting firmness or yielding softness, is essentially determined by the adrenal glands, especially in time of stress and strain.

Brown-Sequard was the first to show that extracts of sex glands could increase the capacity for muscular work.  Whether this was a direct effect upon the muscles, or indirect through the nerves or other endocrines, no one can say.  Certainly the carriage of an individual, outer symptom of the inner tonus among his muscles and tendons, may be said to be as distinctively an endocrine affair as the color of his skin.  And like its variations, variations of their tone, development, reactivity, fatigability, and endurance may be traced to corresponding states of overaction, or underaction, and odd combinations of the different hormones.  Much remains to be learned about them and the manner of their control.  Such an affliction as flatfoot, dependent upon a laxity of the ligaments in one who seems perfectly healthy and strong, may lead the analyst back to a thymus-centered personality.  That is but one example.

Since, too, muscle attitudes, muscle tensions and muscle relaxations play so large a part in the production of fundamental mental states:  the attitudes, moods, memories and will reactions, the vegetative apparatus enters, to play its part as a determinant.

SEX