f higher ones.

But gradually with that increase of activity which we see on ascending
to successively higher grades of animals, and especially with that
increased complexity of life which we also see, there came more and more
into play as a factor, the inheritance of those modifications of
structure caused by modifications of function. Eventually, among
creatures of high organization, this factor became an important one; and
I think there is reason to conclude that, in the case of the highest of
creatures, civilized men, among whom the kinds of variation which affect
survival are too multitudinous to permit easy selection of any one, and
among whom survival of the fittest is greatly interfered with, it has
become the chief factor: such aid as survival of the fittest gives,
being usually limited to the preservation of those in whom the totality
of the faculties has been most favourably moulded by functional changes.

Of course this sketch of the relations among the factors must be taken
as in large measure a speculation. We are now too far removed from the
beginnings of life to obtain data for anything more than tentative
conclusions respecting its earliest stages; especially in the absence of
any clue to the mode in which multiplication, first agamogenetic and
then gamogenetic, was initiated. But it has seemed to me not amiss to
present this general conception, by way of showing how the deductive
interpretation harmonizes with the several inferences reached by
induction.

* * * * *

In his article on Evolution in the _Encyclopaedia Britannica_, Professor
Huxley writes as follows:--

"How far 'natural selection' suffices for the production of
species remains to be seen. Few can doubt that, if not the whole
cause, it is a very important factor in that operation.... On the
evidence of palaeontology, the evolution of many existing forms of
animal life from their predecessors is no longer an hypothesis, but
an historical fact; it is only the nature of the physiological
factors to which that evolution is due which is still open to
discussion."

With these passages I may fitly join a remark made in the admirable
address Prof. Huxley delivered before unveiling the statue of Mr. Darwin
in the Museum at South Kensington. Deprecating the supposition that an
authoritative sanction was given by the ceremony to the current ideas
concerning organic evolutio