inheritance of its race.

When we reflect that we are dealing with the heredity of acquired
qualities which came to development in the most diverse parts of the
parent organism, it must seem in a high degree mysterious how those
parts can have any kind of influence upon a germ which develops
itself in an entirely different place. Many mystical theories have
been propounded for the elucidation of this question, but the
following reflections may serve to bring the cause nearer to the
comprehension of the physiologist.

The nerve substance, in spite of its thousandfold subdivision as
cells and fibres, forms, nevertheless, a united whole, which is
present directly in all organs--nay, as more recent histology
conjectures, in each cell of the more important organs--or is at
least in ready communication with them by means of the living,
irritable, and therefore highly conductive substance of other cells.
Through the connection thus established all organs find themselves in
such a condition of more or less mutual interdependence upon one
another, that events which happen to one are repeated in others, and
a notification, however slight, of a vibration set up {77} in one
quarter is at once conveyed even to the farthest parts of the body.
With this easy and rapid intercourse between all parts is associated
the more difficult communication that goes on by way of the
circulation of sap or blood.

We see, further, that the process of the development of all germs
that are marked out for independent existence causes a powerful
reaction, even from the very beginning of that existence, on both the
conscious and unconscious life of the whole organism. We may see