CHAPTER II


THE MUSCLES AND MOTOR POWERS IN GENERAL


Muscles as organs of the will, of character and even of thought--The
muscular virtues--Fundamental and accessory muscles and functions--The
development of the mind and of the upright position--Small
muscles as organs of thought--School lays too much stress upon
these--Chorea--vast numbers of automatic movements in children--Great
variety of spontaneous activities--Poise, control and spurtiness--Pen
and tongue wagging--Sedentary school life _vs_ free out-of-door
activities--Modern decay of muscles, especially in girls--Plasticity
of motor habits at puberty.

The muscles are by weight about forty-three per cent. of the average
adult male human body. They expend a large fraction of all the kinetic
energy of the adult body, which a recent estimate places as high as
one-fifth. The cortical centers for the voluntary muscles extend over
most of the lateral psychic zones of the brain, so that their culture
is brain building. In a sense they are organs of digestion, for which
function they play a very important role. Muscles are in a most
intimate and peculiar sense the organs of the will. They have built
all the roads, cities, and machines in the world, written all the
books, spoken all the words, and, in fact, done everything that man
has accomplished with matter. If they are undeveloped or grow relaxed
and flabby, the dreadful chasm between good intentions and their
execution is liable to appear and widen. Character might be in a sense
defined as a plexus of motor habits. To call conduct three-fourths of