greater length than, as I believe, any other writer. He likewise
often assumes that I attribute nothing to variation, independently of
natural selection, whereas in the work just referred to I have collected
a greater number of well-established cases than can be found in any
other work known to me. My judgment may not be trustworthy, but after
reading with care Mr. Mivart's book, and comparing each section with
what I have said on the same head, I never before felt so strongly
convinced of the general truth of the conclusions here arrived at,
subject, of course, in so intricate a subject, to much partial error.

All Mr. Mivart's objections will be, or have been, considered in the
present volume. The one new point which appears to have struck many
readers is, "That natural selection is incompetent to account for the
incipient stages of useful structures." This subject is intimately
connected with that of the gradation of the characters, often
accompanied by a change of function, for instance, the conversion of a
swim-bladder into lungs, points which were discussed in the last chapter
under two headings. Nevertheless, I will here consider in some detail
several of the cases advanced by Mr. Mivart, selecting those which are
the most illustrative, as want of space prevents me from considering
all.

The giraffe, by its lofty stature, much elongated neck, fore legs, head
and tongue, has its whole frame beautifully adapted for browsing on the
higher branches of trees. It can thus obtain food beyond the reach of
the other Ungulata or hoofed animals inhabiting the same country; and
this must be a great advantage to it during dearths. The Niata cattle
in South America show us how small a difference in structure may make,
during such periods, a great difference in preserving an animal's
life. These cattle can browse as well as others on grass, but from the
projection of the lower jaw they cannot, during the often recurrent
droughts, browse on the twigs of trees, reeds, etc., to which food the
common cattle and horses are then driven; so that at these times the
Niatas perish, if not fed by their owners. Before coming to Mr. Mivart's
objections, it may be well to explain once again how natural selection
will act in all ordinary cases. Man has modified some of his animals,
without necessarily having attended to special points of structure, by
simply preserving and breeding from the fleetest individuals, as with
the race-horse and g