thorough appreciation of the older
classical or Cuvierian morphology that characterise Gegenbaur's work.
According to Haeckel,[381] Gegenbaur was greatly influenced by J. Mueller,
who, as we know, laid as much stress on function as on form.

The "General Part" of Gegenbaur's text-book is in many ways a
significant document and deserves close attention.

We note first of all that physiology and morphology are considered by
Gegenbaur to be entirely distinct sciences, with different
subject-matter and different methods. "The task of physiology is the
investigation of the functions of the animal body or of its parts, the
referring back of these functions to elementary processes and their
explanation by general laws. The investigation of the material
substratum of these functions, of the form of the body and its parts,
and the explanation of this form, constitute the task of Morphology"
(2nd ed., p. 3).

Morphology falls naturally into two divisions--comparative anatomy and
embryology. The method of comparative anatomy is _comparison_ (p. 6),
and in employing this method account is to be taken of "the spatial
relations of the parts to one another, their number, extent, structure,
and texture." Through comparison one is enabled to arrange organs in
continuous series, and it comes out very clearly during this proceeding
"that the physiological value of an organ is by no means constant
throughout the different form-states of the organ, that an organ,
through the mere modification of its anatomical relations, can subserve
very different functions. Exclusive regard for their physiological
functions would place morphologically related organs in different
categories. From this it follows that in comparative anatomy we should
never in the first place consider the function of an organ. The
physiological value comes only in the second place into consideration,
when we have to reconstruct the relations to the organism as a whole of
the modification which an organ has undergone as compared with another
state of it. In this way comparative anatomy shows us how to arrange
organs in series; within these series we meet with variations which
sometimes are insignificant and sometimes greater in extent; they affect
the extent, number, shape, and texture of the parts of an organ, and can
even, though only in a slight degree, lead to alterations of position"
(p. 6).

Geoffroy St Hilaire would have subscribed to every word of this
vindicatio