ly cease, not to begin again till the dog has
been gone for perhaps fifteen minutes. The churning movements of the
intestine cease along with those of the stomach, and, as other
experiments show, even the gastric juice stops flowing into the
stomach. The whole business of digestion halts during the state of
anger. So anger is an organic state, without doubt. At least in
cats--but the same is found to be true of man, and hence the excellent
rule not to get angry on a full stomach.

Stomach-inhibition is not the only internal response during anger. The
heart, so long regarded as the seat of the emotions, does beat more
forcibly than usual; and the diaphragm, where the old Greeks located
the emotions, does make extra-strong breathing movements. There are
yet other and more curious changes that have recently been discovered
by the physiologists.

Glandular Responses During Emotion

Thus far, we have been considering muscular responses, but now we must
turn our attention to the glands. The glands are often affected during
emotion, as witness the shedding of tears in grief, sweating in anger,
the dry mouth during fear due to inhibition of the salivary glands,
and the stoppage of the gastric juice during anger, as just noted.
These particular glands all pour out their secretions either upon the
skin or upon the mucous membrane of the mouth, stomach, etc.; and such
secretion is called "external" in distinction from the "internal
secretion" of certain other glands which may be called the glands of
internal secretion or the "endocrine glands". Internal secretions are
{123} discharged into the blood vessels, and carried by the blood to
all parts of the body, and they have important effects on the activity
of various organs.

Of the endocrine glands, we will mention only two, which are known to
play an important part in mental life.

The thyroid gland, situated in the lower part of the neck, is
necessary for normal brain activity. Without its internal secretion,
brain activity is very sluggish.

The adrenals, two little glands located near the kidneys (whence their
name, though they have nothing to do with the kidney in function),
have a close connection with such emotions as anger. In the normal or
neutral state of the organism, the adrenal secretion oozes slowly into
the blood, and has a tonic influence on the heart and muscles. But let
an anger stimulus occur, and within a few seconds the adrenals are
secreting rapidly