und
inflicted on but one generation is sometimes found to have so
impressed the germ-cells that they hand down its scars to offspring,
how much more shall not anxieties that have directed action of all
kinds from birth till death, not in one generation only but in a
longer series of generations than the mind can realize to itself,
modify, and indeed control, the organization of every species?

I see Professor S. H. Vines, in the article on Weismann's theory
referred to in my preceding article, says Mr. Darwin "held that it
was not the sudden variations due to altered external conditions
which become permanent, but those slowly produced by what he termed
'the accumulative action of changed conditions of life.'" Nothing
can be more soundly Lamarckian, and nothing should more conclusively
show that, whatever else Mr. Darwin was, he was not a Charles-
Darwinian; but what evidence other than inferential can from the
nature of the case be adduced in support of this, as I believe,
perfectly correct judgment? None know better than they who clamour
for direct evidence that their master was right in taking the
position assigned to him by Professor Vines, that they cannot
reasonably look for it. With us, as with themselves, modification
proceeds very gradually, and it violates our principles as much as
their own to expect visible permanent progress, in any single
generation, or indeed in any number of generations of wild species
which we have yet had time to observe. Occasionally we can find
such cases, as in that of Branchipus stagnalis, quoted by Mr.
Wallace, or in that of the New Zealand Kea whose skin, I was assured
by the late Sir Julius von Haast, has already been modified as a
consequence of its change of food. Here we can show that in even a
few generations structure is modified under changed conditions of
existence, but as we believe these cases to occur comparatively
rarely, so it is still more rarely that they occur when and where we
can watch them. Nature is eminently conservative, and fixity of
type, even under considerable change of conditions, is surely more
important for the well-being of any species than an over-ready power
of adaptation to, it may be, passing changes. There could be no
steady progress if each generation were not mainly bound by the
traditions of those that have gone before it. It is evolution and
not incessant revolution that both parties are upholding; and this
being so, rapid visible