654: Dynamic Theory. 



ing its head round and looking behind in an astonished manner ; " at 

 point 6, " clutching movement of the left paw, with protrusion of the 

 claws ;" at point 13, "twitching backwards of the left ear, and rota- 

 tion of the head to the left and slightly upwards, as if the animal were 

 listening ; " at point 17, " restlessness, opening of the mouth, and long 

 continued cries as of rage or pain ; " at point 18 (on the underside of 

 the hemisphere, not shown in the figure) "the animal suddenly starts 

 up, throws back its head, opens its eyes widely, lashes its tail, pants, 

 screams and spits, as if in furious rage ;" at point 20, "sudden con- 

 traction of the muscles of the front of the chest and neck and of the 

 depressors of the lower jaw, with panting movement." " Similar re- 

 sults were so constantly obtained, with variations obviously depending 

 upon the degree of excitability and the strength of the stimulus, that 

 the localization of the centers of these and other actions was placed be- 

 yond doubt ; the movements of the paws being centralized in the region 

 between points 1, 2 and 6, those of the eyelids and face between 17 and 

 8, the lateral movements of the head and ear in the region of points 9 

 to 14, and the movements of the mouth, tongue and jaws, with certain 

 associated movements of the neck, being localized in the convolutions 

 bordering on the fissure of sylvius (B), which marks the division be- 

 tween the anterior and middle lobes of the cerebrum ; the center for 

 opening the mouth being in front of the under part of the fissure, while 

 that which acts in closure of the jaws is more in the fissure." These 

 deductions in localizing the centers of muscular movement, cannot be 

 accepted as conclusive except upon confirmation by facts of a different 

 kind. Thus, when the animal starts up, throws back its head, opens 

 its eyes, lashes its tail, pants, screams, spits, &c. , when stimulated at 

 point 18, it does not follow that point 18 is the center for the various 

 muscular movements of head, eyes, tail, &c. , because we know that 

 there are many localities in the regions of the internal senses, the agita- 

 tion of which might lead to motor action. Any purpose is founded, in 

 greater or less part, upon compounded memories, it may be of sight, 

 sound, or some other sense, or upon relationships among external things, 

 the perceptions of which constitute sensations of intermedial degrees, 

 and when formed are registered as such in some department of the in- 

 ternal sense region. It may be that No. 18 is such a point registering 

 these condensed perceptions. From a point thus agitated the stimulus, 

 if excessive, would overflow to motor nerves, and muscles would, by 

 their motion, give "expression" to the agitated state of No. 18, for 

 example. We commonly say that the screaming and spitting of a cat 

 indicate rage. Rage, then, is, in essence, the name we give to the 

 molecular agitation of a certain patch or combination of cortical cells. 

 We know nothing objectively of rage except by its muscular expres- 



