ve arisen as new
formations, he writes:--"Against this supposition the whole weight of
all those objections can be directed that are to be brought in general
against the method of explanation which consists in appealing without
imperative necessity to the _Deus ex machina_, 'New formation,' which is
neither better nor worse than _Generatio equivoca_" (p. 21).

Of a similar nature was the objection to convergence.[456]

Why, we may ask, were morphologists so unwilling to admit the creative
power of life? Dohrn, for instance, was fully aware of the great
transforming influence exerted by function upon form--his theory of
_Functionswechsel_ regards as the most powerful agent of change the
activity of the animal, its effort to make the best use of its organs,
to apply them at need in new ways to meet new demands. Why then did he
not go a step further and admit that the animal could by its own
subconscious efforts form entirely new organs? Why did most
morphologists join with him in belittling the organism's power of
self-transformation?

The reasons seem to have been several. There is first the fundamental
reason, that the idea of an active creative organism is repugnant to the
intelligence, and that we try by all means in our power to substitute
for this some other conception. In so doing we instinctively fasten upon
the relatively less living side of organisms--their routine habits and
reflexes, their routine structure--and ignore the essential activity
which they manifest both in behaviour and in form-change.

We tend also to lay the causes of form-change, of evolution, as far as
possible outside the living organism. With Darwin we seek the
transforming factors in the environment rather than within the organism
itself. We fight shy of the Lamarckian conception that the living thing
obscurely works out its own salvation by blind and instinctive effort.
We like to think of organisms as machines, as passive inventions[457]
gradually perfected from generation to generation by some external
agency, by environment or by natural selection, or what you will. All
this makes us chary of believing that Nature is prodigal of new organs.

Other causes of the unwillingness of morphologists to admit the new
formation of organs are to be sought in the main principle of pure
morphology itself, that the unity of plan imposes an iron limit upon
adaptation, and in the powerful influence exercised at the time by
materialistic habits of