animals.

It is true that palæontology gives direct testimony about the evolutionary
succession of animals in geologic time. But we now know that embryology is
even more direct in its proof that organic transformation is natural and
real; while at the same time there is a completeness in the full series of
developmental stages connecting the one-celled egg with the adult creature
that must be forever lacking in the case of the fossil sequence of
species. If paragraphs and pages are missing from the brief embryonic
recapitulation, whole chapters and volumes of the fossil series have been
lost for all time. The investigators whose task it has been to decipher
the story of the earth's evolution have had to meet numerous and
exasperating difficulties which do not confront the embryologist and
anatomist who study living materials. Nevertheless the library of
palæontological documents is one which has been founded for over a
century, and it has grown fast during recent decades, so that consistent
accounts may now be read of the great changes in organic life as the earth
has altered and grown older. And in all this record, there is not a single
line or word of fact that contradicts evolution. What definite evidence
there is tells uniformly in favor of the doctrine, for it is possible, in
the first place, to work out the order of succession of many of the great
groups of animals, and this order is found to be the same as that
established by the other bodies of evidence. Secondly, some fossil groups
are astonishingly complete, so that the ancient history of a form like the
horse can be written with something approaching fullness. Finally, the
remains of certain animals have been found so situated in geological ways,
and so constructed anatomically, that the zoölogist is justified in
denoting them "missing links," because they seem to have been intermediate
between groups that have diverged so widely during recent epochs as to
render their common ancestry scarcely credible.