there has got to be some registration effected in the nervous
system, some line of transit worn for nervous force to follow;
there has got to be a connection between certain nerve-centres
before the thing can be done, whether it is the acts of the viscera
or the acts of the limbs, or anything of that sort; and of course
it is obvious that if the creature has not many things to register
in his nervous system, if he has a life which is very simple,
consisting of few actions that are performed with great frequency,
that animal becomes almost automatic in his whole life; and all the
nervous connections that need to be made to enable him to carry on
life get made during the foetal period or during the egg period,
and when he comes to be born, he comes all ready to go to work. As
one result of this, he does not learn from individual experience,
but one generation is like the preceding generations, with here and
there some slight modifications. But when you get the creature
that has arrived at the point where his experience has become
varied, he has got to do a good many things, and there is more or
less individuality about them; and many of them are not performed
with the same minuteness and regularity, so that there does not
begin to be that automatism within the period during which he is
being developed and his form is taking on its outlines. During
prenatal life there is not time enough for all these nervous
registrations, and so by degrees it comes about that he is born
with his nervous system perfectly capable only of making him
breathe and digest food,--of making him do the things absolutely
requisite for supporting life; instead of being born with a certain
number of definite developed capacities, he has a number of
potentialities which have got to be roused according to his own
individual experience. Pursuing that line of thought, it began
after a while to seem clear to me that the infancy of the animal in