two different breeds of the species Homo Sapiens. The
materials being different, the color and feel of them is different,
and the resistance to wear and tear is different.

ENDOCRINE ANALYSIS

The modes of classification glimpsed at are certainly exceedingly
broad and sweeping. It is well enough to establish types and classes.
But beneath them are sheltered the infinite possibilities of
permutations and combinations, which explain the countless variety
and complexity of form and function. Every individual born among the
vertebrates, for example, must have a certain definite amount and
percentage of pituitary gland, anterior and posterior, pineal,
thyroid, parathyroid, thymus, adrenal, pancreas, interstitial and
so on. Now if, to state it in terms of percentages, for the sake of
argument, the pituitary is 25, the pineal 10, the thyroid 36, the
parathyroids 15, the thymus 29, the adrenals 60, the pancreas 49, the
interstitials 72 (the gland when acting maximally to be graded as
100), we see at once how different such an individual must be from one
who has, say, pituitary 84, pineal 39, thyroid 26, parathyroid 42,
adrenals 96, pancreas 22 and interstitials 89. One obtains at once
from the contrasts of such figures some idea of the possibilities. As
each point plus or minus must count to produce some difference in the
individual, the results are manifest. Varying within the numerical
limits imposed by genus, species, variety and family (which limits
are probably responsible for the persistence of the particular genus,
species, variety, or family) the individual becomes an individual
because of the relative values of the percentages in his blood and
tissues of these different internal secretions. We thus begin to gain
an insight into the patterns according to which men, women and animals
are woven.

We are, as yet, far from an exact endocrine analysis of the
individual. But we know that the endocrines rule over growth and
nutrition, a vast dominion which incorporates every organ and every
tissue. By enhancing or retarding the nutritional changes, the growth
of the organ or tissue is favored or restricted. The size and shape of
an individual, as a whole, as well as of the specialized cell masses
composing him, as hands and feet, the nose and ears, and so on, are
therefore controlled by them. Whether an organism is to be tall or
short, lean or corpulent, graceful or awkward, is decided by their
interactions. These, like hu