The Darwinian Hypothesis | Page 7

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
carcass 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 recognize the operation

of secondary causes in events where ignorance beheld an immediate
intervention of a higher power? And when we know that living things
are formed of the same elements as the inorganic world, that they act
and react upon it, bound by a thousand ties of natural piety, is it
probable, nay is it possible, that they, and they alone, should have no
order in their seeming disorder, no unity in their seeming multiplicity,
should suffer no explanation by the discovery of some central and
sublime law of mutual connexion?
Questions of this kind have assuredly often arisen, but it might have
been long before they received such expression as would have
commanded the respect and attention of the scientific world, had it not
been for the publication of the work which