106 



ZOOLOGY. 



Experiments on living animals, surgical operations, and acci- 

 dents, have repeatedly proved that the seat of perception is 

 not in the spinal marrow. The cutting this across in a living 



Fig. 69. A, Brain of the Cod. B, Brain of the Shark. 



animal merely destroys the sensibility, and paralyzes the 

 movements of all the parts supplied with nerves from it helow 

 the point divided. 



With the brain it is quite otherwise. The surface of the 

 brain and its substance generally, may be cut or irritated in 

 a living animal without it being sensible of any injury or 

 pain; but remove it, and the whole body of the animal 



Fig. 70. Brain of the Sparrow. 



instantly becomes insensible. The action of the brain is as 

 essential in the perception of sensations as for the acts of 

 volition. 



199. The insensibility of the brain when cut or rudely 

 touched is a remarkable circumstance, long known, however, 

 to surgeons. But the faculty of perceiving sensations caused 



