e teeth influenced. But as each tooth is a miniature organ,
inspectable by the eye as a unit, the action of the ductless glands
is more obviously reflected for the observer to read. By their teeth
shall ye know them. Upon the whole history of the evolution of each
tooth, in the growth of the dental follicle and its walls, the
fruition of the dentinal germ, the making of the enamel organ, the
dental pulp, the cementum and the peridental membrane, the endocrines
leave their mark.

There are certain general statements about the teeth and the internal
secretions that can be made. The teeth of the thyroid types are
pearly, glistening, small and regular; in other words, the teeth to
which poets have devoted sonnets. The pituitary types have teeth that
are large and square and irregular, with prominence of the middle
incisors, and a marked separation or crowding of them. The
interstitial types have small irregular upper teeth, with turned,
stumpy or missing lateral incisors. The thymus types have youthful,
milky white teeth that are thin and translucent, and scalloped or
crescentic at the grinding edge. The teeth of the adrenal type are all
well-developed, tend to have a yellowish color, with a reddish tinge
to the grinding surfaces.

The degree and regularity of development of the middle upper cutting,
biting teeth, as distinguished from the grinding molars, the middle
and lateral incisors, and the canines offer further guides to the
endocrine constitution analysis. The size of the central incisors
seems to be directly proportional to the degree of pituitary
predominance. On the other hand, the size and regularity of
the lateral incisors seem proportional to the influence of the
interstitial cells. When these are inferior in the make-up of an
individual, the lateral incisors are nearly always distorted. The
size of the canines appears to be a measure of adrenal activity. Long
sharply pointed canines mean well-functioning adrenal gland equipment
to start in with, inherited from a bellicose progenitor.

No individual peculiarities of the teeth are accidental. Just as the
absence of hair on the face in a man or a moustache effect in a
woman stand for some definite stress or strain in the mechanics of
interaction of the internal secretions, so likewise do variations in
dentition, as to the time of eruption of the teeth, their position and
quality, and their resistance to decay.

Proper balance between the thymus and pituitar