on a comparison of the food with residual
products.

I will only call your attention to the fact, that the exceptional
phenomenon of the laboratory is the prevailing law of the organism.
Nutrition itself is but one great catalytic process. As the blood
travels its rounds, each part selects its appropriate element and
transforms it to its own likeness. Whether the appropriating agent be
cell or nucleus, or a structureless solid like the intercellular
substance of cartilage, the fact of its presence determines the
separation of its proper constituents from the circulating fluid, so that
even when we are wounded bone is replaced by bone, skin by skin, and
nerve by nerve.

It is hardly without a smile that we resuscitate the old question of the
'vis insita' of the muscular fibre, so famous in the discussions of
Haller and his contemporaries. Speaking generally, I think we may say
that Haller's doctrine is the one now commonly received; namely, that the
muscles contract in virtue of their own inherent endowments. It is true
that Kolliker says no perfectly decisive fact has been brought forward to
prove that the striated muscles contract without having been acted on
by nerves. Yet Mr. Bowman's observations on the contraction of isolated
fibres appear decisive enough (unless we consider them invalidated by Dr.
Lionel Beale's recent researches), tending to show that each elementary
fibre is supplied with nerves; and as to the smooth muscular fibres, we
have Virchow's statement respecting the contractility of those of the
umbilical cord, where there is not a trace of any nerves.

In the investigation of the nervous system, anatomy and physiology have
gone hand in hand. It 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 prepar