A familiar instance will make the point at issue plain. Everyone knows
that in many respects, in the structure of the skeleton, and the curve
of the backbone, and in the development of the brain, the man-like
monkeys, the gorilla and its allies, are intermediate between man and
the lower monkeys. In the early days of evolution it was assumed
frequently that the gorilla, etc., were therefore to be regarded as
ancestors of man, and they appear as such in more than one well-known
treatise on evolutionary biology. We now know that it is exceedingly
probable that the gorilla and its allies, although truly intermediate
types, and truly shewing a possible path of evolution from the brute
to man, are not the actual ancestors of man, but cousins, descendants
like man from some more or less remote common ancestor. And the
tendency of recent advances in knowledge is more and more to throw
stress on the value of Huxley's distinction, and to minimise confusion
between "intermediate" and truly ancestral types.

CHAPTER VI

HUXLEY AND DARWIN

Early Ideas on Evolution--Erasmus Darwin--Lamarck--Herbert
Spencer--Difference between Evolution and Natural
Selection--Huxley's Preparation for Evolution--The Novelty of
Natural Selection--The Advantage of Natural Selection as a
Working Hypothesis--Huxley's Unchanged Position with regard to
Evolution and Natural Selection from 1860 to 1894.

From our attempt to place together as much as possible of Huxley's
geological work in the last chapter, it followed that we anticipated
much that falls properly within this chapter. The year 1859, the date
of publication of _The Origin of Species_, is a momentous date in the
history of this century, as it was the year in which there was given
to the world a theory that not only revolutionised scientific opinion,
but altered the trend of almost every branch of thought. To understand
this great change, and the part played in it by Huxley, it is
necessary to be quite clear as to what Darwin did. In the first place,
he did not invent evolution. The idea that all the varied structures
in the world, the divergent forms of rocks and minerals and crystals,
the innumerable trees and herbs that cover the face of the earth like
a mantle, and all the animal host of creatures great and small that
dwell on the land or dart through the air or people the waters,--that
all these had arisen by natural laws from a primitive unforme