HISTORY OR THE REFLEX THEORY. 
203 
Thus the path was cleared for Marshall Hall. Ample evi- 
dence had been collected to prove that there were other centres 
of nervous action besides the brain ; that the phenomena which 
depended on these centres were those actions usually styled 
instinctive and automatic, and those observed in decapitated 
animals ; and that these centres were situated in the spinal chord 
and medulla oblongata. While some thought that these centres 
were sensorial, others said, No : they insisted on the brain only 
being capable of “ sensation ;” so that all acts which were not 
dependent on the brain, were said to be divorced from con- 
sciousness. In 1833 Marshall Hall first disclosed his theory, 
which was briefly this : — There is a distinct class of actions, 
called reflex actions, wholly independent of sensation or vohtion. 
These belong to a distinct nervous mechanism, “The true spinal 
system,” with a separate set of nerves, the excitor and the 
motor nerves. An impression on the surface is conveyed by 
an incident, excitor nerve to the spinal centre, and, instead of 
being transmitted upwards to the brain, is immediately reflected 
along the motor nerve to the muscle. 
On comparing this with Prochaska’s statement, it will be seen 
that the only differences are in denying the presence of sensation, 
and in supposing the existence of a separate anatomical mechan- 
ism, “ the true spinal system.” The first of these differences 
is a matter of opinion on a point wholly incapable of proof, but 
in which the presumptive evidence is, I conceive, wholly against 
Marshall Hall. The second of these differences is an hypothesis, 
which Hall never attempted to prove anatomically (though his 
distinguished disciple, Mr. Grainger, attempted it for him), 
and which is universally rejected by all Europe. 
Thus, although Marshall Hall has the credit of having revived 
(not originated) the Reflex Theory, and, by his more precise 
application of it to various physiological and pathological 
phenomena, has given it a new importance in the eyes of the 
scientific world, his claims as a “ discoverer ” are reduced to 
that of a systematizer. That which was new in his theory is 
now universally rejected as erroneous ; that which was true in 
it was known to others. But he systematised and placed in a 
striking light what was confused and obscure; he made the 
Reflex Theory the doctrine of the schools. Such is the verdict 
which the impartial world of science will deliver ; and if it is 
somewhat different from the verdict prophesied by Professor 
Bennett, it is quite in accordance with what a physiologist, 
greatly his superior, has delivered : — “ The facts had been 
witnessed and reasoned upon by various physiologists,” says 
Professor Sharpey, “ but to Dr. Marshall Hall belongs the 
credit of having fully shown the connection with each other, of 
having first successfully generalized them, and of having given 
to this part of physiology the form of a consistent doctrine; and 
