examined,
placed the fact of the decussation of the pyramids--denied by Haller, by
Morgagni, and even by Stilling--beyond doubt. So the spinal canal, the
existence of which, at least in the adult, has been so often disputed,
appears as a coarse and unequivocal anatomical fact in many of the
preparations referred to.

While these studies of the structure of the cord have been going on,
the ingenious and indefatigable Brown-Sequard has been investigating the
functions of its different parts with equal diligence. The microscopic
anatomists had shown that the ganglionic corpuscles of the gray matter
of the cord are connected with each other by their processes, as well
as with the nerve-roots. M. Brown-Sequard has proved by numerous
experiments that the gray substance transmits sensitive impressions and
muscular stimulation. The oblique ascending and descending fibres from
the posterior nerve-roots, joining the "longitudinal columns of the
cornua," account for the results of Brown-Sequard's sections of the
posterior columns. The physiological experimenter has also made it
evident that the decussation of the conductors of sensitive impressions
has its seat in the spinal core, and not in the encephalon, as had been
supposed. Not less remarkable than these results are the facts, which
I with others of my audience have had the opportunity of observing, as
shown by M. Brown-Sequard, of the artificial production of epilepsy in
animals by injuring the spinal cord, and the induction of the paroxysm
by pinching a certain portion of the skin. I would also call the
student's attention to his account of the relations of the nervous
centres to nutrition and secretion, the last of which relations has been
made the subject of an extended essay by our fellow countryman, Dr. H.
F. Campbell of Georgia.

The physiology of the spinal cord seems a simple matter as you study it
in Longet. The experiments of Brown-Sequard have shown the problem to
be a complex one, and raised almost as many doubts as they have solved
questions; at any rate, I believe all lecturers on physiology agree that
there is no part of their task they dread so much as the analysis of the
evidence relating to the special offices of the different portions of
the medulla spinalis. In the brain we are sure that we do not know
how to localize functions; in the spinal cord, we think we do know
something; but there are so many anomalies, and seeming contradictions,
and sources of