type
differs as much from the adrenal type as does a greyhound from a
bull-dog. The greyhound has a certain size, form, character and
capacity. The bull-dog has similar qualities which are yet quite
different. Each is built for a particular career. Among human beings,
the pure thyroid type is easily distinguished from the pure adrenal
type, and both of these from the pure pituitary type. Each is stamped
with a significant figure, height, skin, hair, temperament, ambition,
social reactions and predisposition to certain diseases.

THE MIXED TYPES

Among the mixed types, the lines of distinction are less clear, and so
they are more difficult to classify. The mixed types may be said to
be hyphenated. In them, two or even three of the internal secretory
glands conflict for predominance. The combined action makes for a
resultant modification in the primary glandular markings and effects.
A hyphenated classification thus becomes inevitable. Especially is
this so if the two glands are mutually antagonistic and inhibitory.
A compromise effect is then necessitated. Or an individual may be
dominated by one gland at one period of his life and by another at a
later period. One of the glands, the thyroid, for example, will show,
by the traces it has left upon the earliest developing features, that
it was in control at the very earliest dates of his history, while
other signs will disclose the more recent influence of the adrenal
or of the pituitary. The combination becomes classifiable as the
thyroid-pituitary type, or as the thyroid-adrenal type.

That the external features as well as the chronic diseases of human
beings are controlled by some common factor has long been suspected.
Inquiries into morbid phenomena with a hereditary trend yielded
information that has paved the way for the internal secretion theory.
It has long been known that certain diseases effect only certain
individuals of a definite constitution. Apoplexy, diabetes,
arteriosclerosis, Bright's disease, are met with almost exclusively in
what the older clinicians talked about as the apopleptic type. On the
other hand, they said, anemias, tuberculosis, hemophilias, scrofulas
occurred more among the lymphatic type. But they had no idea whatever
of the true functional basis of the two different types. The truth
as we of today view it is that these two types represent different
textures of human beings, fabricated of different internal secretions.
They are really