stematic relationship done away with, for
instance through saltatory evolution, the mere fact of descent would not
bring the two species any nearer one another. Thus the case proves only
systematic relationship, and only evolution. But as to the meaning of this
systematic relationship, whether it can be "explained" by descent, whether
it has existed from all eternity, or how it has arisen, the experiment
does not inform us.

The same idea may be illustrated in regard to Weismann's "predicting."
This, too, is a proof of evolution, but not of descent. Exactly as
Weismann predicted the striping of the hawk-moth caterpillars and the
human _os centrale_, Goethe predicted the formation of the skull from
modified vertebrae, and the premaxillary bone in man. In precisely the same
way he "derived" the cavities in the human skull from those of the animal
skull. This was quite in keeping with the manner and style of his Goddess
Nature and her creative transformations, raising the type of her creations
from stage to stage, developing and expanding each new type from an
earlier one, yet keeping the later analogous to and recapitulative of the
earlier, recording the earlier by means of vestigial and gradually
dwindling parts.

But what has all this to do with descent? Even the "biogenetic law"
itself, especially if it were correct, would fit admirably into the frame
of the pure evolution idea. For it is quite consistent with that idea to
say that the higher type in the course of its development, especially in
its embryonic stages, passes through stages representative of the forms of
life which are below it and precede it in the (ideal) genealogical tree.
Indeed, the older doctrine of evolution took account of this long ago.

"The same step-ladder which is exhibited by the whole animal kingdom, the
steps of which are the different races and classes, with at the one
extreme the lowliest animals and at the other the highest, is exhibited
also by every higher animal in its development, since from the moment of
its origin until it has reached its full development it passes
through--both as regards internal and external organisation--the essentials
of all the forms which become permanent for a lifetime in the animals
lower than itself. The more perfect the animal is, the longer is the
series of forms it passes through."

So J. Fr. Meckel wrote in 1812 in his "Handbook of Pathological Anatomy,"
_with no thought of descent_. And the facts