rents of blood and lymph. In that
commonly fatal condition of the arteries which follows rapidly upon the
state of blood pressure known as hardening of the arteries, or
arterio-sclerosis, a practically incurable condition hitherto, the
results obtained by the goat-gland transplantation are miraculously
swift. When the arteries are, as the doctor puts it, "as hard as
pipe-stems," they grow in a few weeks, sometimes in a week, soft and
pliable. The change, according to Dr. Brinkley, is brought about in the
walls of the arteries themselves, and is not a process of dissolving the
accumulations or deposits of calcareous material within the arteries.
The change is in the material of the walls of the arteries, producing a
return of the condition of elasticity, permitting expansion and
contraction as in youth.

It is a favorite theory with some modern writers that the physical
change from youth to age is accompanied in the body, and in a sense
caused by, the deterioration in the quality of the cells of the body,
and they call this change a breaking-down process by which the finer and
more highly differentiated cells, such, for example, as the nerve-cells,
and others which have high and complicated duties to perform, are
displaced by cells of an inferior type, which they name conjunctive
cells, much as the common sparrow drives away the songbirds from the
home garden and, usurping the place of the songbird, substitutes a
wretched twitter for the golden notes of the warblers which once
delighted our ears. The common cells, also, on usurping the place of the
nobler cells, are unable to perform the difficult duties of the latter,
and the result upon human organism is disorder, decay, disease, etc.,
contributing to, if not causing, the condition of old age. This is an
ingenious but not convincing theory. Our knowledge of histological
processes is too incomplete at this stage to permit its acceptance as
fact. It assumes too much to be known which is quite unknown. Moreover,
it refutes itself upon examination in this particular, and in several
others, that if it were true that these inferior cells are on the
lookout to invade instantly any part of the human organism in which
there was a breaking down of nerve-tissue, for example, then it would be
impossible to build new nerve-tissue to take the place of that which was
destroyed, because its place, according to this theory, has been already
taken by an intruder who cannot be dislodged.