30 Mr. Carlisle’s Lecture on muscular Motion. 
entirely supplied by nerves coming from ganglions, appear of 
this class ; and thus the animal motions are principally regu- 
lated by the external stimuli, of which the occurrence seems 
to agree with the animal necessities : but the extensive illus- 
trations which comparative anatomy affords on this point, are 
much too copious for any detail in this place. 
There are two states of muscles, one active, which is that of 
contraction, the other, a state of ordinary tone, or relaxation, 
which may be considered passive, as far as it relates to the 
mind ; but the sensorial or nervous power seems never to be 
quiescent, as it respects either the voluntary or involuntary 
muscles during life. The yielding of the sphincters appears to 
depend on their being overpowered by antagonist muscles, 
rather than on voluntary relaxation, as is commonly supposed. 
I have now finished this endeavour to exhibit the more recent 
historical facts connected with muscular motion. 
It will be obvious to every one, that much remains to be done, 
before any adequate theory can be proposed. I have borrowed 
from the labours of others, without acknowledgement, because 
it would be tedious to trace every fact, and every opinion to its 
proper authority : many of the views are perhaps peculiar to 
myself, and I have adduced many general assumptions and 
conclusions, without offering the particular evidence for their 
confirmation, from a desire to keep in view the remembrance of 
retrospective accounts, and to combine them with intimations 
for future research. The due cultivation of this interesting 
pursuit cannot fail to elucidate many of the phenomena in 
question, to remove premature and ill founded physiological 
opinions, and eventually to aid in rendering the medical art 
more beneficial, by establishing its doctrines on more extensive 
and accurate views of the animal economy. 
