166 THE NERVOUS SYSTEM. 



jump forward. There can be no doubt that, in the lower 

 animals, movements may take place which are completely 

 divorced from the will, sensation, and consciousness; for 

 in those animals, as well as in man, these faculties have 

 Iheir principal seat within the brain. 



36. An irritation is necessary, in most instances, to 

 awaken reflex movements. In the case of the decapitated 

 fowl, its muscles are excited to convulsive action by 

 reason of its being thrown upon the hard ground and 

 roughly handled. Let it be treated differently, and the 

 convulsions will not take place : let it be laid gently upon 

 soft cotton, and the body will remain comparatively quiet. 

 It may comfort some people to know that the convulsions 

 which follow decapitation are not attended with pain ; nor 

 are they a necessary part of the " act of death," as some 

 suppose. 



37. In the human body, likewise, actions are excited 

 that are entirely distinct from the ordinary voluntary 

 efforts. It is not permissible, desirable, nor even necessary 

 to decapitate a man that the body may be disconnected 

 from his brain, in order to test the effect of irritation upon 

 the spinal cord; although the bodies of beheaded crimi- 

 nals have been experimented upon, and caused to move by 

 powerful galvanic batteries. The resort to such means of 

 experiment is rendered unnecessary by the occurrence of 

 certain deplorable cases of disease and injury, which effect- 

 ually sever all communication between the brain and a 

 large part of the body. 



38. Thus, the cord may be so far injured, as the result 

 of accident, as to terminate all sensation and voluntary 

 motion in the lower half of the body, the patient seem- 

 ingly becoming lifeless and powerless from the waist down- 

 ward. And yet, by tickling or pinching either foot, the leg 



36. What i? necessary in most cases to awaken reflex movements? In tha 

 case of the fowl ? Convulsions which follow decapitation ? 



37. Actions in the human body distinct from voluntary efforts? 



38. Reflex action after injury'of the cord ? Why not'due to the muscles ? 



