to
which it is adapted in the organic edifice."[75] But from this sentence
it is not clear that Goethe understood the principle as one of form
independent of function, for he seems to consider that the homology of
an organ is partly determined by the function which it performs for
the whole. He wavers between the purely formal or morphological
interpretation of the principle of connections and the functional. We
find him in the additions to the _Entwurf_ (1796), saying:--"We must
take into consideration not merely the spatial relations of the parts,
but also their living reciprocal influence, their dependence upon and
action on one another." [76] But in seeking for the intermaxillary bone
in man he was guided by its position relative to the maxillaries--it
must be the bone between the anterior ends of the maxillaries, a bone
whose limits are indicated in the adult only by surface grooves.

As a matter of fact Goethe's morphological views are neither very
clearly expressed nor very consistent. This comes out in his treatment
of the relation between structure and function. Sometimes he takes the
view that structure determines function. "The parts of the animal," he
writes, "their reciprocal forms, their relations, their particular
properties determine the life and habits of the creature."[77] We are
not to explain, he says, the tusks of the _Babirussa_ by their
possible use, but we must ask how it comes to have tusks. In the same
way we must not suppose that a bull has horns in order to gore, but we
must investigate the process by which it comes to have horns to gore
with. This is the rigorous morphological view. On the other hand he
admits elsewhere that function may influence form. Apparently he did
not work out his ideas on this point to logical clearness, and Radl[78]
is probably correct in saying that the following quotation with its
double assertion represents most nearly Goethe's position:--

"Also bestimmt die Gestalt die Lebensweise des Thieres, Und die Weise
zu leben, sie wirkt auf alle Gestalten Maechtig zurueck."[79]

His best piece of purely morphological work was his theory of the
metamorphosis of plants. Stripped of its vaguer elements, and of the
crude attempt to explain differences in the character of plant organs
by differences in the degree of "refinement" of the sap supplied to
them, the theory is that stem-leaves, sepals, petals, and stamens are
all identical members or appendages. These appendages