wn body,
whose migrations and activities remind one much more of a social organism
than of a machine). The organism arises, not from mechanical, but from
"harmoniously-equipotential systems": that is to say, from systems every
element of which has equal functional efficiency; so that each individual
part bears within itself in an equal degree the potentiality of the
whole--an impossibility from the mechanical point of view.

Driesch had given an experimental basis for this theory at an earlier
stage, in his experiments on the initial stages of the development of
sea-urchins, starfishes, zoophytes, and the like. A Planarian worm cut
into pieces developed a new worm of smaller size from each part. A
mutilated Pluteus larva developed a new food-canal, and restored the whole
typical form. His experiment of 1892 went farther still, for he succeeded
in separating the first four segmentation-cells of the sea-urchin's egg;
and from each cell obtained a developing embryo. These facts, he
maintains, compel us to assume a mode of occurrence which is dynamically
_sui generis_, a "prospective tendency" which is a sub-concept in the
Aristotelian "Dynamis." And the essential difference between this kind of
operation and a mechanical operation is, that the same typical effect is
always reached, even if the whole normal causal nexus be disturbed. Even
when forced into circuitous paths the embryo advances towards the same
goal. Thus "vitalism," that is, the independence and autonomy of the vital
processes, is proved. The effect required is attained through "action at a
distance," a mode of happening which is specifically different from
anything to be found in the inorganic world, and which has its
_directive_, for instance, in the regeneration of lost parts, _not_ in
anything corporeal or substantial, but in the end to be attained.

In his work on "Organic Regulations," Driesch collects from the most
diverse biological fields more and more astonishing proofs of the activity
of the living as contrasted with physico-chemical phenomena, and of the
marvellous power the organism has to "help itself" and to attain the
typical form and reach the end aimed at, even under the greatest diversity
in the chain of conditions. The material here brought forward is enormous,
and the author's grasp of it very remarkable; and not the least of the
merits of the book is, that the bewildering wealth and diversity of these
phenomena, which are usually present