the larger and more general movements of the body ripen first, and those
governing the finer motor adjustments later. For example, the larger body
muscles of the child which are concerned with sitting up come under control
earlier than those connected with walking. The arm muscles develop control
earlier than the finger muscles, and the head and neck muscles earlier than the
eye muscles. So also the more general and less highly specialized powers of the
mind ripen sooner than the more highly specialized. Perception and observation
precede powers of critical judgment and association. Memory and imagination
ripen earlier than reasoning and the logical ability.
This all means that our educational system must be planned to follow the order
of nature. Children of the primary grades should not be required to write with
fine pencils or pens which demand delicate finger adjustments, since the brain
centers for these finer coördinations are not yet developed. Young children
should not be set at work necessitating difficult eye control, such as stitching
through perforated cardboard, reading fine print and the like, as their eyes are
not yet ready for such tasks. The more difficult analytical problems of arithmetic
and relations of grammar should not be required of pupils at a time when the
association areas of the brain are not yet ready for this type of thinking. For such
methods violate the law of nature, and the child is sure to suffer the penalty.
4. IMPORTANCE OF HEALTH AND VIGOR OF THE NERVOUS
SYSTEM
Parallel with opportunities for proper stimuli and response the nervous system
must possess good tonicity, or vigor. This depends in large degree on general
health and nutrition, with freedom from overfatigue. No favorableness of
environment nor excellence of training can result in an efficient brain if the
nerve energy has run low from depleted health, want of proper nourishment, or
exhaustion.
The Influence of Fatigue.—Histologists find that the nuclei of nerve cells are
shrunk as much as fifty per cent by extreme fatigue. Reasonable fatigue followed
by proper recuperation is not harmful, but even necessary if the best
development is to be attained; but fatigue without proper nourishment and rest is
fatal to all mental operations, and indeed finally to the nervous system itself,
leaving it permanently in a condition of low tone, and incapable of rallying to
strong effort. For rapid and complete recuperation the cells must have not only
the best of nourishment but opportunity for rest as well.