the carbon which is the
fundamental element in all living organisms. We know the requisite
conditions: the supply of raw material, and the sunlight from which the
energy is derived. But how the chlorophyll makes use of these to effect
the breaking up, and how it starts the subsequent syntheses of the carbon
into the most complex organic compounds remains a mystery. And so on
upwards through all the strictly vital phenomena.

Wiesner's(89) view of things is essentially similar. He gives a very
impressive picture of the mystery of the chemistry of the plant, showing
how small is the number of food-stuffs and raw materials in comparison to
the thousands of highly complex chemical substances which the plant
produces, and how much work there is involved in de-oxydising the food and
in forming syntheses. He, too, refuses, as usual, to postulate "vital
force." Yet to speak of "the fundamental peculiarities of the living
matter inherent in the organism" and to admit that plants are "irritable,"
"heliotropic," "geotropic," &c., amounts to much the same thing as
postulating vital force; that is to say, to a mere naming of the specific
problem of life without explaining it. The author himself admits this when
he says in another place: "If I compare organisms with inorganic systems,
I find that the progress of our knowledge is continually enlarging the
gulf which separates the one from the other!"

These anti-mechanical tendencies show themselves most emphatically in the
work of Fr. Ludwig.(90) In his concluding chapter, after a discussion of
the theories of Darwin, Naegeli, and Weismann, he postulates, for
variation, heredity, and species-formation in particular, "forces other
than physico-chemical," "let us call them frankly psychical."

It is instructive to see how these "vitalistic" views crop up even in
studies of detail and of the microscopically small, as for instance in E.
Crato's "Beitraege zur Anatomie und Physiologie des Elementar-organismus."
How the living organism contains within itself what is in its turn living,
down into ever smaller detail, (amoeboid movements of certain plastines,
physodes,) how incomparable the living organism is with a "machine," to
which its libellers are so fond of likening it, how it builds itself up,
steers, and stokes itself, how it produces with "playful ease" the most
marvellous and graceful forms, makes combinations and breaks them up, how
analogous its whole activity is to "being able