The most fertile branch of Medicine today is the study of the body's glands and the chemicals called hormones which those glands manufacture and distribute through the body.
The pituitary seems to be the most important gland in the body. It is a reddish-grey oval mass the size of a hazel nut, and lies in a bony case at the base of the brain. Apparently the pituitary keeps all the other glands teamed up. (The thyroid keeps them steamed up.) If the pituitary gland does not supply the secretions which the body needs, doctors in some cases can remedy the deficiency by administering manufactured extracts. In case of too much ''secretion, extracts of other glands restrain the overactive pituitary. Sometimes a brain surgeon can cut out a piece of the gland and thus reduce its output.
Generally accredited as the nation's foremost investigator of pituitary hormones and functions is Dr. Herbert McLean Evans. 50. big. shy, ever-investigating professor of biology in the University of California and director of its Institute of Experimental Biology at Berkeley. Professor Evans was the first deliberately to make giants by injecting normal animals with pituitary growth hormones. He was also first to discover Vitamin E, which is necessary for reproduction in higher animals. The past year he has been laboring, with no letup, at the Rockefeller Institute in Manhattan. This week he and Mrs. Evans left Manhattan for Berkeley with a ninth, tenth, and perhaps an eleventh pituitary hormone which he and helpers have isolated.
One of these is an adrenalotropic hormone. When the pituitary gland fails to send enough adrenalotropic substance through the blood, then another set of glands, the adrenals, which are essential to life, wastes away. But the exact relation of hormones of the two glands is not yet clear.
Another hormone discovered by Dr. Evans is diabetogenic. Contrary to insulin, this pituitary factor causes the body to accumulate sugar.
A last new hormone of the pituitary, possibly identified by Dr. Evans, apparently magnifies the effect of one of the female sex hormones and seems to have a sex-stimulating effect of its own.
But the pituitary gland, of which Dr. Evans is the master, is only one of nine organs positively known to secrete hormones. Of these organs, the stomach, intestine and pancreas are not ''ductless glands." "Ductless glands" are the pituitary, the thyroid and the parathyroids (they lie in the neck), the adrenals (one rests on each kidney), the ovaries and the testes, all of which came in for attention fortnight ago at the meeting of the American Medical Association in Milwaukee.*
It is already clearly established that the proportion of hormones manufactured and distributed by the ductless glands determines the varying nature of the various bodies, minds and temperaments which various humans have.