us system, these of late years
have been shown to be--I do not say identical in any sense with the
electrical processes--but this has been shown, that they are in some
way or other associated with them; that is to say, that every amount
of nervous action is accompanied by a certain amount of electrical
disturbance in the particles of the nerves in which that nervous action
is carried on. In this way the nervous action is related to electricity
in the same way that heat is related to electricity; and the same sort
of argument which demonstrates the two latter to be related to one
another shows that the nervous forces are correlated to electricity; for
the experiments of M. Dubois Reymond and others have shown that whenever
a nerve is in a state of excitement, sending a message to the muscles
or conveying an impression to the brain, there is a disturbance of the
electrical condition of that nerve which does not exist at other times;
and there are a number of other facts and phenomena of that sort; so
that we come to the broad conclusion that not only as to living matter
itself, but as to the forces that matter exerts, there is a close
relationship between the organic and the inorganic world--the difference
between them arising from the diverse combination and disposition of
identical forces, and not from any primary diversity, so far as we can
see.

I said just now that the Horse eventually died and became converted
into the same inorganic substances from whence all but an inappreciable
fraction of its substance demonstrably originated, so that the actual
wanderings of matter are as remarkable as the transmigrations of the
soul fabled by Indian tradition. But before death has occurred, in the
one sex or the other, and in fact in both, certain products or parts of
the organism have been set free, certain parts of the organisms of
the two sexes have come into contact with one another, and from that
conjunction, from that union which then takes place, there results the
formation of a new being. At stated times the mare, from a particular
part of the interior of her body, called the ovary, gets rid of a minute
particle of matter comparable in all essential respects with that which
we called a cell a little while since, which cell contains a kind of
nucleus in its centre, surrounded by a clear space and by a viscid mass
of protein substance (Fig. 2); and though it is different in appearance
from the eggs which we are mostly ac