their walls into the atmosphere, to be absorbed by our bodies.

There are certain terms for the glands of internal secretion which
are used interchangeably. They are spoken of often as the _endocrine_
glands and as the _hormone_ producing glands. Endocrine is most
convenient for it stands for both the gland and its secretion. Hormone
is employed a good deal in the literature of the subject. But it
applies specifically to the internal secretion, and not to the gland.

THE EXPERIMENTAL PIONEER

All this clarification of the concept of the glands of internal
secretion occurred in the first quarter of the nineteenth century.
However, no inkling of their real importance to the body, of which
quantitatively they form so insignificant a part, was apparently
revealed to anyone. Not even the most daring speculation or brilliant
guess work in physiology engaged them as material. Thus Henle, the
great anatomist, calmly affirmed that these glands "have no influence
on animal life: they may be extirpated or they degenerate without
sensation or motion suffering in the least." Johann Müller, the most
celebrated physiologist of his day and contemporary of Henle, wrote
in 1844 and coolly stated, "The ductless glands are alike in one
particular--they either produce a different change in the blood which
circulates through them or the lymph which they elaborate plays a
special rôle in the formation of blood or of chyle." In other words,
they were dismissed as curious nonentities, of no real significance
to the running of the body. Laennec, the French founder of the Art of
Diagnosis in Medicine, once said that nothing about a science is more
interesting than the progress of that science itself. He might have
added that nothing either was more interesting than the contradictions