their constituent bodily parts." The essential feature of life is a
derived and communicated force _additional_ to the molecular forces.
Whence it comes we are not told. He glided all round the problem with
platitudinarian expressions, which were intended to show his own adherence
as a matter of course to the new biological school, and which revealed at
the same time his striking incapacity for defining a problem with any
precision. At a "certain period in the evolution of the earth" this force
arose, as the ordinary mechanical movements "swung over" into the vital.
But it is thus a special form of movement, which detaches itself from the
great constants of general movement, and runs its course alongside of, and
in constant relation to, these. (Did ever vitalist assert more?) After
thus preparing the way for a return of the veering process at a particular
stage of evolution, and giving the necessary assurances against the
"diametrically opposed dualistic position," Virchow employs almost all the
arguments against the mechanical theory which vitalists have ever brought
forward. Even the catalytic properties of ferments are above the
"ordinary" physical and chemical forces. The movement of crystallisation,
too, cannot be compared with the vital movement. For vital force is not
immanent in matter, but is always the product of previous life.(78) In the
simplest processes of growth and nutrition the _vis vitalis_ plays its
vital _role_. This is true in a much greater degree of the processes of
development and morphogenesis. In the phenomena of irritability life
reveals its spontaneity through "responses," and so on. "Peu d'anatomie
pathologique eloigne du vitalisme, beaucoup d'anatomie pathologique y
ramene."

It is impossible to make much of this position. It leaves the theory with
one of the opposing parties, the practice with the other, and the problem
just where it was before.

Preyer's Position.

Along with Virchow, we must name another of the older generation, the
physiologist William Preyer, who combated "vitalism," "dualism," and
"mechanism" with equal vehemence, and issued a manifesto, already somewhat
solemn and official, against "vital force." And yet he must undoubtedly be
regarded as a vitalist by mechanists and vitalists alike.(79) He is more
definite than Virchow, for he does not content himself with general
statements as to the "origin" of vital force, and of the "swinging over"
of the merely mechan