The thyroid gland, the pituitary gland, the adrenal glands, the thymus, the pineal, the sex glands, have yielded secrets.

The thyroid type differs as much from the adrenal type as does a greyhound from a bull-dog.

The Adam's apple, poetic popular name for the thyroid cartilage, is never prominent, because it is not ossified, as it should be in the normal male.

One may sum it up by saying that the thyroid secretion is the great controller of the speed of living.

In the thyroid deficiency of adults, a prominent phenomenon often is the falling out of the hair in handfuls.

Quick thinking, as we call it, means good thyroid action, and slow thinking deficient thyroid action.

In certain states of excessive thyroid activity there is an extra stimulation of the instinctive display of the person which may go on to boasting, mania and exhibitionism.

Little more than a hundred years ago, it was observed that certain organs, like the thyroid body in the neck, and the adrenal capsules in the abdomen, hitherto neglected because their function was hopelessly obscure, had a glandular structure.

As illustrations, there are the cases of thyroid deprivation in human beings, cretinism and myxedema, as well as those in which it is believed there occurs an excess of the thyroid secretion in the blood and tissues, the condition of hyperthyroidism.

Then there is infantilism, which is helped by the giving of thyroid extract.

The opsonins, for example, those substances which butter the bacteria so that the appetite of the white cells for them is properly roused, are mobilized by thyroid feeding or injection.

On the other hand, in states of thyroid insufficiency, depression is produced, which may go on to melancholia, a desire to be alone, to hide, to sit apart and even a tendency to accuse the self of various uncommitted crimes and sins.

Then Schiff, in 1884, neglected twenty-five years, came back, with an array of demonstrations, proving that the various symptoms, tremors, spasms and convulsions, following removal of the thyroid, could be prevented by a previous graft of a piece of the gland under the skin, or by the injection of thyroid juice into a vein or under the skin, or by the ingestion of thyroid juice or the raw thyroid by mouth.

A, epiglottis; B, thyroid cartilage; C, cricoid-thyroid membrane, connecting with the cricoid cartilage below, all forming the larynx; D, one of the rings of the trachea.

It is possible to speak of thyroid moods, adrenal moods, ante-pituitary or post-pituitary moods, gonadal moods.

It is hence permissible to think of the thyroid as a dictator of evolution, to crown it as the vertebrate gland par excellence, and to call the typical vertebrate brand marks secondary thyroid characteristics in precisely the sense of Darwin classing the horns of cattle as secondary sexual characteristics.

The isolation of thyroxin has made possible the determination of the influence of the thyroid hormone upon the evolution of energy in any higher animal organism.

He elaborated on the discoveries and experiments of Professor Leonard Huxley in England with thyroid gland injections, of Voronoff in France with the grafting of interstitial glands of monkeys, and of Eugen Steinach in Austria and Roux in Germany, with germ glands and X-rays.

" Sensitivity, the ability to discriminate between grades of sensation or acuteness of perception is another thyroid quality.

The memory of thyroid insufficients is wretched.

Yet, should the administration of the thyroid cease, an almost immediate reversion to the original vegetative condition is inevitable.

That his thyroid energy capacity did not fail him is indicated by the fact that at St. Albans he would ride for three hours at the end of the day to tire himself sufficiently for sleep.

But while there is a normal mechanism for thyroid detoxication, the cocaine or heroin derivatives mark the tissues permanently with their scars and deform the personality.

Energy and sensitivity in an individual should direct attention to the thyroid element predominating in his composition.

Certain types of thyroid excess associated with the thymus dominant next to be described are peculiarly susceptible to emotional instability.