ertebrates; the mammals, birds, reptiles,
amphibians and fish. For if the differences of their bodily structure
could be shown to be one of degree and not radical, it could be
supposed that the lines of demarcation which now delimitate the larger
types might some day vanish. A single illustration suffices for
Fleischmann's purpose, viz., the plan of structure of the limbs of the
different classes of vertebrates. The four higher classes are
characterized by a common underlying plan of limb structure, whilst
fish have one peculiar to themselves. On the other hand it is an
inevitable postulate of the doctrine of Descent that fish are the
original progenitors of all other vertebrates. Hence the five-joint
limbs of the latter must have developed from the fins of fish. This
derivation was actually attempted but without success, as Fleischmann
points out at considerable length. By means of citations taken from the
writings of Darwinian adherents, he illustrates the confusion which
even now reigns among them on this matter. The evolution of the
remaining vertebrates from the fish is therefore a wholly gratuitous
assumption devoid of any foundation in fact.

Fleischmann further discusses the "parade-horse" of the theory of
Descent. It has been the common belief, especially fostered by Haeckel,
that the history of the Descent of our present horse lies before us in
its complete integrity as pictured in the drawings of Marsh. Here
Fleischmann again proves at great length the insufficiency of actually
available materials. Of special importance is his repeated demand that
not only individual parts of the animals but the whole organism as well
should be derived from the earlier forms. If, for instance, it be
possible to arrange horses and their tertiary kindred in an unbroken
line of descent according to the formation of their feet, whilst the
other characteristics (teeth, skull-structure, etc.,) do not admit of
arrangement in a corresponding series, the first line must be
surrendered.

Very similar to this is the case of the "family history of birds,"
which as all know, has been traced back to reptiles. It is in this
matter that the famous Archaeopteryx plays an important part.
Unfortunately, however, grave difficulties are again encountered in
this connection. This primitive form is a real bird according to
Zittel; and according to the same investigator as also according to
Marsh, Dames, Vetter, Parker, Tuerbringen, Parlow and Meh