proficiency. He who marvels at the skill with which the spider
weaves her web should bear in mind that she did not learn her art all
on a sudden, but that innumerable generations of spiders acquired it
toilsomely and step by step--this being about all that, as a general
rule, they did acquire. Man took to bows and arrows if his nets
failed him--the spider starved. Thus we see the body and--what most
concerns us--the whole nervous system of the new-born animal
constructed beforehand, and, as it were, ready attuned for
intercourse with the outside world in which it is about to play its
part, by means of its tendency to respond to external stimuli in the
same manner as it has often heretofore responded in the persons of
its ancestors.

We naturally ask whether the brain and nervous system of the human
infant are subjected to the principles we have laid down above? Man
certainly finds it difficult to acquire arts of which the lower
animals are born masters; but the brain of man at birth is much
farther from its highest development than is the brain of an animal.
It not only grows for a longer time, but it becomes stronger than
that of other living beings. The brain of man may be said to be
exceptionally young at birth. The lower animal is born precocious,
and acts precociously; it resembles those infant prodigies whose
brain, as it were, is born old into the world, but who, in spite of,
or rather in addition to, their rich endowment at birth, in after
life develop as much mental power as others who were less splendidly
furnished to start with, but born with greater freshness of youth.
Man's brain, and indeed his whole body, affords greater scope for
individuality, inasmuch as a relatively greater part of it is of
post-natal growth. It develops under the influence of impressions
made by the environment upon its senses, and thus makes its