minal and Puritan. And in the
chapter on historic personages, we tracked some of the story in
detail. This vein when explored will quarry untold riches. It has been
observed that financiers of mark, like great musicians, are special
pituitary types. Also that the financiers are voracious meat eaters
and the musicians inordinately fond of sweets. Differences in anterior
and posterior predominances might account for this. That we are
playing here with no phantasy is proven by the fact that we can effect
changes of tastes as well as of intellectual direction by appropriate
feeding of various glandular extracts. Just as much, indeed, as we can
influence sex susceptibility, and the reaction to sex stimulation, by
the artificial introduction from without of the proper hormones.

FATIGUE AND INDUSTRY

In industry, business and profession, the biologist will come more and
more to be called as consultant. Labor unions as well as the large
employers of labor, and their employment managers have given much
thought to the problem of fatigue. Just what fatigue is, why different
individuals tire at different rates, why some are constructed for
monotonous routine while others must have constant variety and change,
the relation to accidents and to quantity output, are a few of the
major lines of inquiry upon which the endocrines obviously have a
large bearing. To the employment manager, labor turnover and the
selection of personnel are adjacent fields of research.

Fatigue as an endocrine deficiency--a depressed state of one or
more of the glands of internal secretion, abolished when its normal
functioning is restored--is a general principle from which departures
of exploration of sub-problems will proceed. An endocrine organ will
secrete at a certain rate. When it is stimulated excessively, it will
eject extra amounts of its secretion. How long the period of excessive
stimulation may last must depend upon the secretion potential or
margin of reserve of the cells, varying from organ to organ, and from
individual to individual. After that, exhaustion and failure follows,
with the onset of the symptoms of fatigue.

A pretty demonstration of this process has been worked out in the
electrical stimulation of muscle. If a muscle, say the biceps, is
irritated by an electric current, it will contract. As the strength of
the current is increased, the degree of contraction becomes greater.
A sort of stepladder effect of increasing contraction