tion.

So much is known about the adrenal cortex. Upon the medulla, the
interior gland of the gland, there has been lavished an amount of
attention beside which the cortex is to be classed as a neglected
wall-flower. Nearly everything that possibly could be determined
about an internal secretion has in its case been settled or plausibly
guessed at. The cells manufacturing the secretion, its exact chemistry
and function, its action upon the blood, the liver and spleen, the
heart and lungs, the brain and nervous system, have been minutely
investigated, studied and charted. Its source in the food, its fate in
the body, its place in the history of the individual and the species,
its importance as a weapon in the struggle for existence, and the
survival of the fittest have been made the subject of an astonishing
number of researches, considering the short period of scarce three
decades that intensive science has centered its barrage upon it.

In the first place, the medulla contains numerous nerve cells,
belonging to the vegetative, also called the sympathetic nervous
system. But these nerve cells are merely minor notes of the symphony.
The motif is settled by a majority of large, granular cells, which
stain a distinctive yellowish-brown when the gland is fixed in a
solution of bichromate of potash. All chromium salts, in fact, stain
the therefore labelled chromaffin cells. The characteristic staining
power appears to be dependent upon, or correlated with, the presence
of the internal secretion of the medulla of the adrenal, adrenalin.
For the content of adrenalin, as calculated chemically, and the
depth of stain as seen under the microscope, rise and fall together.
Chromaffin reaction and adrenalin content go together. The poisonous
skin glands of the toad have been found to give a marked chromaffin
reaction, and to contain a large amount of adrenalin. Other masses
of cells in the human body, especially along the course of the
sympathetic nervous system, have been shown to give the reaction and
to contain adrenalin.

The erratic Brown-Sequard pounded and hammered away for more than
thirty years on the importance to life of the adrenal glands, since
death occurred so quickly after their removal. But it was not until
Schaefer, the Scotch physiologist, (who has done more than any other
living man to stimulate study of the internal secretions) found that
an extract of them, when injected into a vein, produced a remarkable
t