only satisfactory clue. And the fact, which
Fleischmann does not discuss, that even at present we may observe the
establishment of what are at least new breeds, impels us to accept an
analogous origin of new species. Even if the biogenetic law really "finds
its chief confirmation in its exceptions," even if we cannot speak of a
strict recapitulation of earlier stages of evolution, there are
indisputable facts which are most readily interpreted as reminiscences, as
due to affiliation (ideal or hereditary), with ancestral forms. (Note, for
instance, Weismann's "prediction," &c.(24)) Even if Archaeopteryx and other
intermediate forms cannot be regarded as connecting links in the strict
sense, _i.e._, as being stages in the actual pedigree, yet the occurrence
of reptilian and avian peculiarities side by side in one organism, goes
far to prove the close relationship of the two classes.

Fleischmann's book strengthens the impression gained elsewhere, that a
general survey of the domain of life as a whole gives force and
convincingness to the Theory of Descent, while a study of details often
results in breaking the threads and bringing the difficulties into
prominence. But the same holds true of many other theoretical
constructions, and yet we do not seriously doubt their validity. (Take,
for instance, the Kant-Laplace theory, and theories of ethnology, of the
history of religion, of the history of language, and so on.) And it is
quite commonly to be observed that those who have an expert and specialist
knowledge, who are aware of the refractoriness of detailed facts, often
take up a sceptical attitude towards every comprehensive theory, though
the ultimate use of detailed investigation is to make the construction of
general theories possible. Fleischmann does exactly what, say, an
anthropologist would do if, under the impression of the constancy and
distinctiveness of the human races, which would become stronger the more
deeply he penetrated, he should resignedly renounce all possibility of
affiliating them, and should rest content with the facts as he found them.
Similarly, those who are most intimately acquainted with the races of
domesticated animals often resist most strenuously all attempts, although
these seem to others a matter of course, to derive our "tame" forms from
"wild" species living in freedom.

But to return. Even where the Theory of Descent is recognised, whether
fully or only half-heartedly, the recognition