molecular structure of the germ-plasm is already determined
within the embryo; and Weismann holds that there are no facts which
really prove that acquired characters can be inherited, although their
inheritance has, by most writers, been considered so probable as hardly
to stand in need of direct proof.

"We have already seen in the earlier part of this chapter that many
instances of change, imputed to the inheritance of acquired variations,
are really cases of selection."

And the rest of the remarks tend to convey the impression that Mr.
Wallace adopts Professor Weismann's view, but, curiously enough, though I
have gone through Mr. Wallace's book with a special view to this
particular point, I have not been able to find him definitely committing
himself either to the assertion that acquired modifications never are
inherited, or that they sometimes are so. It is abundantly laid down
that Mr. Darwin laid too much stress on use and disuse, and a residuary
impression is left that Mr. Wallace is endorsing Professor Weismann's
view, but I have found it impossible to collect anything that enables me
to define his position confidently in this respect.

This is natural enough, for Mr. Wallace has entitled his book
"Darwinism," and a work denying that use and disuse produced any effect
could not conceivably be called Darwinism. Mr. Herbert Spencer has
recently collected many passages from "The Origin of Species" and from
"Animals and Plants under Domestication," {26} which show how largely,
after all, use and disuse entered into Mr. Darwin's system, and we know
that in his later years he attached still more importance to them. It
was out of the question, therefore, that Mr. Wallace should categorically
deny that their effects were inheritable. On the other hand, the
temptation to adopt Professor Weismann's view must have been overwhelming
to one who had been already inclined to minimise the effects of use and
disuse. On the whole, one does not see what Mr. Wallace could do, other
than what he has done--unless, of course, he changed his title, or had
been no longer Mr. Wallace.

Besides, thanks to the works of Mr. Spencer, Professor Mivart, Professor
Semper, and very many others, there has for some time been a growing
perception that the Darwinism of Charles Darwin was doomed. Use and
disuse must either do even more than is officially recognised in Mr.
Darwin's later concessions, or they must do a great deal less. If