I have filled in with some detail this thumbnail sketch of thyroid deprivation as it occurs in infancy to illustrate how wide a sweep the gland’s lariat embraces.  Skin, hair, bones, muscle and fat, brain and intelligence, growth and development, are modified precisely as the size and shape of certain crystals are modified by the presence or absence of ingredients in an apparently homogeneous solution.  A fertilized ovum, in which the predecessor of the thyroid gland is present, that is to say, in which there is the seed and soil for its sprouting, looks the same as one without that formative material.  Yet, when the time comes for the internal secretion of the thyroid to put in its oar in the metabolic game, its presence or absence makes all the difference in the world to the individual.

In the middle of the nineteenth century, when the concentration of phosphorus in the brain was established as significant, the cry for the emphasis of that fact was—­without phosphorus no thought is possible.  We can much more relevantly declare that without thyroid, no thought, no growth, no distinctive humanity or even animality is possible.  For the epigram about phosphorus was bombast, since it can be declaimed with equal truth that without oxygen, without carbon, without nitrogen, without any of the food elements that go to make up the chemical composition of brain matter, no thought is possible.  Indeed, if one were set upon the indictment of a single chemical element as the begetter of consciousness, the prisoner at the bar would have to be copper.  There is more copper in the brain by a considerable degree than in any other organ of the body.  Which perhaps will be exceedingly regretted by the patrons of the aristocracy of the soul who would have it as an emanation of a deposit in the brain of silver at least, if not gold.  They are like the old lady who would never permit herself to be cured of her ailments except by gold plated pills.  Copper, however, is not necessary to intelligence.  Without thyroid there can be no complexity of thought, no learning, no education, no habit-formation, no responsive energy for situations, as well as no physical unfolding of faculty and function, and no reproduction of kind, with no sign of adolescence at the expected age, and no exhibition of sex tendencies thereafter.

EFFECTS OF FEEDING THYROID

How subtly the internal secretion affects every phase and aspect of child as well as adult, by doing something to the speed of activities in their cells, is told straightway by the effects of it when eaten or introduced into the skin or blood of various people.  A cretin, idiotic, dwarfish, deformed, hopeless, an incessantly prodding burden of sorrow to the mother, who looks upon the masterpiece she had labored to bring forth, and beholds a terrible gargoyle, becomes transformed when fed thyroid.