een them, the unity of the self
cannot be manifested; there is a plurality of consciousness.

This much admitted, let us return to our special question, which
Flechsig asks in these words: "On what does genius rest? Is it based on
a special structure in the brain, or rather on special irritability?
that is, according to our present notions, on chemical factors? We may
hold the first opinion with all possible force. Genius is always united
to a special structure, to a particular organization of the brain." All
parts of this organ do not have the same value. It has been long
admitted that the frontal part may serve as a measure of intellectual
capacity; but we must allow, contrariwise, that there are other regions,
"principally a center located under the protuberance at the top of the
head, which is very much developed in all men of genius whose brains
have been studied down to our day. In Beethoven, and probably also in
Bach, the enormous development of this part of the brain is striking. In
great scientists like Gauss the centers of the posterior region of the
brain and those of the frontal region are strongly developed. The
scientific genius thus shows proportions of brain-structure other than
the artistic genius."[25] There would then be, according to our author,
a preponderance of the frontal and parietal regions--the former obtain
especially among artists; the latter among scientists. Already, twenty
years before Flechsig, Ruedinger had noted the extraordinary development
of the parietal convolutions in eminent men after a study of eighteen
brains. All the convolutions and fissures were so developed, said he,
that the parieto-occipital region had an altogether peculiar character.

By way of summary we must bear in mind that, as regards anatomical
conditions, even when depending on the best of sources, we can at
present give only fragmentary, incomplete, hypothetical views.

Let us now go on to the physiology.

II

We might have rightly asked whether the physiological states existing
along with the working of the creative imagination are the cause,
effect, or merely the accompaniment of this activity. Probably all the
three conditions are met with. First, concomitance is an accomplished
fact, and we may consider it as an organic manifestation parallel to
that of the mind. Again, the employment of artificial means to excite
and maintain the effervescence of the imagination assigns a causal or
antecedent positio