t is very singular that so important, and seemingly
simple, a fact as the connection of the nerve-tubes, at their origin or
in their course, with the nerve-cells, should have so long remained open
to doubt, as you may see that it did by referring to the very complete
work of Sharpey and Quain (edition of 1849), the histological portion of
which is cordially approved by Kolliker himself.

Several most interesting points of the minute anatomy of the nervous
centres have been laboriously and skilfully worked out by a recent
graduate of this Medical School, in a monograph worthy to stand in line
with those of Lockhart Clarke, Stilling, and Schroder van der Kolk. I
have had the privilege of examining and of showing some of you a number
of Dr. Dean's skilful preparations. I have no space to give even an
abstract of his conclusions. I can only refer to his proof of the fact,
that a single cell may send its processes into several different bundles
of nerve-roots, and to his demonstration of the curved ascending and
descending fibres from the posterior nerveroots, to reach what he has
called the longitudinal columns of the cornea. I must also mention Dr.
Dean's exquisite microscopic photographs from sections of the medulla
oblongata, which appear to me to promise a new development, if not a new
epoch, in anatomical art.

It having been settled that the nerve-tubes can very commonly be traced
directly to the nerve-cells, the object of all the observers in this
department of anatomy is to follow these tubes to their origin. We have
an infinite snarl of telegraph wires, and we may be reasonably sure,
that, if we can follow them up, we shall find each of them ends in a
battery somewhere. One of the most interesting problems is to find the
ganglionic origin of the great nerves of the medulla oblongata, and this
is the end to which, by the aid of the most delicate sections, colored
so as to bring out their details, mounted so as to be imperishable,
magnified by the best instruments, and now self-recorded in the light
of the truth-telling sunbeam, our fellow-student is making a steady
progress in a labor which I think bids fair to rank with the most
valuable contributions to histology that we have had from this side of
the Atlantic.

It is interesting to see how old questions are incidentally settled in
the course of these new investigations. Thus, Mr. Clarke's dissections,
confirmed by preparations of Mr. Dean's which I have myself