Darwiniana | Page 5

basis only, and therefore admit of being
argued to their consequences. And we do this with the less hesitation as
it so happens that those persons who are practically conversant with the
facts of the case (plainly a considerable advantage) have always
thought fit to range themselves under the latter category.
The majority of these competent persons have up to the present time
maintained two positions--the first, that every species is, within certain
defined limits, fixed and incapable of modification; the second, that
every species was originally produced by a distinct creative act. The
second position is obviously incapable of proof or disproof, the direct

operations of the Creator not being subjects of science; and it must
therefore be regarded as a corollary from the first, the truth or falsehood
of which is a matter of evidence. Most persons imagine that the
arguments in favour of it are overwhelming; but to some few minds,
and these, it must be confessed, intellects of no small power and grasp
of knowledge, they have not brought conviction. Among these minds,
that of the famous naturalist Lamarck, who possessed a greater
acquaintance with the lower forms of life than any man of his day,
Cuvier not excepted, and was a good botanist to boot, occupies a
prominent place.
Two facts appear to have strongly affected the course of thought of this
remarkable man--the one, that finer or stronger links of affinity connect
all living beings with one another, and that thus the highest creature
grades by multitudinous steps into the lowest; the other, that an organ
may be developed in particular directions by exerting itself in particular
ways, and that modifications once induced may be transmitted and
become hereditary. Putting these facts together, Lamarck endeavoured
to account for the first by the operation of the second. Place an animal
in new circumstances, says he, and its needs will be altered; the new
needs will create new desires, and the attempt to gratify such desires
will result in an appropriate modification of the organs exerted. Make a
man a blacksmith, and his brachial muscles will develop in accordance
with the demands made upon them, and in like manner, says Lamarck,
"the efforts of some short-necked bird to catch fish without wetting
himself have, with time and perseverance, given rise to all our herons
and long-necked waders."
The Lamarckian hypothesis has long since been justly condemned, and
it is the established practice for every tyro to raise his heel against the
carcase of the dead lion. But it is rarely either wise or instructive to
treat even the errors of a really great man with mere ridicule, and in the
present case the logical form of the doctrine stands on a very different
footing from its substance.
If species have really arisen by the operation of natural conditions, we
ought to be able to find those conditions now at work; we ought to be
able to discover in nature some power adequate to modify any given
kind of animal or plant in such a manner as to give rise to another kind,
which would be admitted by naturalists as a distinct species. Lamarck

imagined that he had discovered this vera causa in the admitted facts
that some organs may be modified by exercise; and that modifications,
once produced, are capable of hereditary transmission. It does not seem
to have occurred to him to inquire whether there is any reason to
believe that there are any limits to the amount of modification
producible, or to ask how long an animal is likely to endeavour to
gratify an impossible desire. The bird, in our example, would surely
have renounced fish dinners long before it had produced the least effect
on leg or neck.
Since Lamarck's time, almost all competent naturalists have left
speculations on the origin of species to such dreamers as the author of
the "Vestiges," by whose well-intentioned efforts the Lamarckian
theory received its final condemnation in the minds of all sound
thinkers. Notwithstanding this silence, however, the transmutation
theory, as it has been called, has been a "skeleton in the closet" to many
an honest zoologist and botanist who had a soul above the mere naming
of dried plants and skins. Surely, has such an one thought, nature is a
mighty and consistent whole, and the providential order established in
the world of life must, if we could only see it rightly, be consistent with
that dominant over the multiform shapes of brute matter. But what is
the history of astronomy, of all the branches of physics, of chemistry,
of medicine, but a narration of the steps by which the human mind has
been compelled, often sorely against its will, to recognise the operation
of secondary causes in events where ignorance beheld an immediate
intervention of a