relation to these detailed facts that criticisms or
even denials of the theory have been most frequent. Koken, otherwise a
convinced supporter of the theory, inquires in his "Vorwelt," _apropos_ of
the tortoises, what has become of the genealogical trees that were
scattered abroad in the world as proved facts in the early days of
Darwinism. He asserts, in regard to _Archaeopteryx_, the instance which is
always put forward as the intermediate link in the evolution of birds,
that it does not show in any of its characters a fundamental difference
from any of the birds of to-day, and further, that, through convergent
development under similar influences, similar organs and structural
relations result, iterative arrangements which come about quite
independently of descent. He maintains, too, that the principle of the
struggle for existence is rather disproved than corroborated by the
palaeontological record.

In embryology, so competent an authority as O. Hertwig--himself a former
pupil of Haeckel's--has reacted from the "fundamental biogenetic law." His
theory of the matter is very much that of Hamann which we have already
discussed; development is not so much a recapitulation of finished
ancestral types as the laying down of foundations after the pattern of
generalised simple forms, not yet specialised; and from these foundations
the special organs rise to different levels and grades of differentiation
according to the type.(29) But we must not lose ourselves in details.

Looking back over the whole field once more, we feel that we are justified
in maintaining with some confidence that the different pronouncements in
regard to the detailed application and particular features of the Theory
of Descent, and the different standpoints that are occupied even by
evolutionists, are at least sufficient to make it obvious that, even if
evolution and descent have actually taken place, they have not run so
simple and smooth a course as the over-confident would have us believe;
that the Theory of Descent rather emphasises than clears away the riddles
and difficulties of the case, and that with the mere corroboration of the
theory we shall have gained only something relatively external, a clue to
creation, which does not so much solve its problems as restate them. The
whole criticism of the "right wing," from captious objections to actual
denials, proves this indisputably. And it seems likely that in the course
of time a sharpening of t