in a situation which is EXCENTRIC in the nervous
system--that is, distant from the nervous centres. This mode of action
has not, I think, been hitherto distinctly understood by physiologists.

"Many of the phenomena of this principle of action, as they occur in
the limbs, have certainly been observed. But, in the first place, this
function is by no means confined to the limbs; for, while it imparts
to each muscle its appropriate tone, and to each system of muscles its
appropriate equilibrium or balance, it performs the still more important
office of presiding over the orifices and terminations of each of the
internal canals in the animal economy, giving them their due form
and action; and, in the second place, in the instances in which the
phenomena of this function have been noticed, they have been confounded,
as I have stated, with those of sensation and volition; or, if they
have been distinguished from these, they have been too indefinitely
denominated instinctive, or automatic. I have been compelled, therefore,
to adopt some new designation for them, and I shall now give the reasons
for my choice of that which is given in the title of this paper--'Reflex
Functions.'

"This property is characterized by being EXCITED in its action and
REFLEX in its course: in every instance in which it is exerted an
impression made upon the extremities of certain nerves is conveyed to
the medulla oblongata or the medulla spinalis, and is reflected along
the nerves to parts adjacent to, or remote from, that which has received
the impression.

"It is by this reflex character that the function to which I have
alluded is to be distinguished from every other. There are, in the
animal economy, four modes of muscular action, of muscular contraction.
The first is that designated VOLUNTARY: volition, originated in the
cerebrum and spontaneous in its acts, extends its influence along the
spinal marrow and the motor nerves in a DIRECT LINE to the voluntary
muscles. The SECOND is that of RESPIRATION: like volition, the motive
influence in respiration passes in a DIRECT LINE from one point of the
nervous system to certain muscles; but as voluntary motion seems to
originate in the cerebrum, so the respiratory motions originate in
the medulla oblongata: like the voluntary motions, the motions of
respirations are spontaneous; they continue, at least, after the eighth
pair of nerves have been divided. The THIRD kind of muscular action
in the anima