490 On the Nervous Systems of 
been still more circumstantially detailed, but it 
appears to me allowable to infer from what is 
actually stated, that those extremities of the 
nerves, usually named their origins, were in this 
Case at least the seat of sensation, &c. 
2. In some animals, as the turtle and frog for 
example, the brain does not appear to be exclu- 
sively the seat of sensation and volition, or the 
power of producing voluntary motion. For, 
if the brain be removed, these animals on the 
application of a stimulus to their limbs, continue 
to shew indisputably by their movements, that 
they are possessed of sensation and volition. 
Here then the spinal marrow, if not the nerves, 
evidently participate the above powers with the 
brain and can exert them independently. of it,* 
3. Some insects and worms, when cut into 
two, or more pieces, become two or more dis- 
tinct and perfect individuals, each possessing 
sensation and voluntary motion. In polypuses 
the nervous substance is not formed into distinct 
visible. fibres, but distributed. equally in every. 
part of the body; and these animals may be 
diyided into an almost infinite number of pieces, - 
each of which becomes a distinct individual, evi- 
dently possessing sensation and voluntary moe 
tion.t For they perceive the agitation of the 
water, in which they are placed: They appear 
* Cuvier Anat. Comp, T. Il. p.94. t+ Ibid p.o5— - 
