stroy and dissolve bacteria are also increased. The
thyroid probably performs these functions by sending its secretion
to the cells directly responsible for the immunity reactions, and
stimulating them to activity.

A sketch of the thyroid like the foregoing shows it as the wondrous
controller of vitality and growth, and indefatigable protector against
intoxicants and injuries. When it is sufficiently active, life is
worth while; when it is defective, life is a difficult threatening
blackness. That would make it out as the gland of glands. It is
tremendously important, without a doubt, in normal everyday life. But
no more so than the other members of the cast. The position of star it
may claim, but in vain. The other glands of internal secretion to
be sketched will each, when the marvels of its business in the
cell-corporation are considered, present itself as candidate for the
honors of the president. Justice should give fair credit to all
the organs which fabricate the reagents of individuality, and the
regulators of personality.

THE PITUITARY

In the human skull, the pituitary is a lump of tissue about the size
of a pea lying at the base of the brain, a short distance behind the
root of the nose. It is of a grayish-yellow color, unpretentious and
insignificant enough in appearance, and so long neglected by the
scientists who boast their immunity to the glamor of the spectacular.
Guesses at its nature date back to Aristotle.

Like most of its colleagues among the glands of internal secretion,
it is really two glands in one, two glands with but a single name. At
least it consists of two different parts, distinct in their origin,
history, function and secretions, but juxtaposed and fused into what
is apparently a homogeneous entity. They are conveniently spoken of as
the anterior gland and the posterior gland.

In the embryo, the anterior gland is derived by a proliferation of
cells from the mouth area. The posterior gland represents an outgrowth
of the oldest part of the nervous system. When it is traced back along
the tree of the vertebrate species, it is found to be present in all
of them. An ancient invention, its precursor has been identified in
worms and molluscs and even among the starfish. "The pituitary
is practically the same, from myxine to man." A trusted veteran,
therefore, among the internal secretory organs, its importance can be
surmised.

To understand the story of the pituitary, variously acqu