76 THE POPULAR SCIENCE MONTHLY. 



has succeeded in completely changing my views on cerebral locali- 

 zation." 



After the dog there was the monkey. Professor Ferrier intro- 

 duced him. He had lost the motor zone in the left hemisphere seven 

 months previously. Of him Professor Ferrier said : " As to any inde- 

 pendent volitional action of the right arm and leg we have not seen a 

 single indication since the operation was made. The animal is, in 

 every other respect, perfectly well, and as to its tactile sensibility there 

 is not the slightest sign of impairment." It is pleasing to know that, 

 as the dog had been faithful to his master, so the monkey was true to 

 his friend ; he displayed the proper amount of paralysis on the oppo- 

 site side of the body. In this connection Dr. Ireland's words are sug- 

 gested. He says, "It is to be hoped, in the interest of the martyrs of 

 cerebral physiology, that definite results will be attained as quickly 

 and with as little suffering as possible." 



Whatever may or may not be accomplished in finding definite cen- 

 ters of the brain for special movements and sensations, one thing stands 

 fast the cerebral hemispheres are the sole organs of the higher intel- 

 lectual manifestations. From the time of Flourens, experiment has 

 again and again shown that complete removal of the hemispheres is 

 followed by stupor. All that resembles intellect disappears sponta- 

 neous volition is gone. The animal remains buried in the profoundest 

 repose. He originates no action. A low form of sensation and a low 

 form of volition may remain. The animal when pinched gives evi- 

 dence of pain ; when set in motion, continues the motion till stopped 

 by external hindrances. A frog deprived of the cerebrum and thrown 

 into the water will swim until land is reached ; a pigeon thrown into 

 the air will fly until stopped by an obstacle or by exhaustion. It is 

 to be particularly observed that the motions of these animals are strict- 

 ly normal, i. e., pure motions ; they are no longer connected with the 

 higher power that once controlled them. They continue because they 

 must continue. 



A writer in the "Journal of Anatomy," of Paris, 1870-'71, gives a 

 clear account of this matter. He says : " As a summary, alike in the 

 inferior and superior animals, the removal of the hemispheres does not 

 cause to disappear any of the movements that previously existed, but 

 these movements assume certain peculiar characters. They are regu- 

 lar, for no psychical influence intervenes to modify them. They take 

 place inevitably after excitation. The physiologist can, at will, in an 

 animal deprived of the brain, determine such and such an act, limit it, 

 arrest it. He can predict all the movements that will take place as 

 certainly as a chemist knows in advance the reaction he will obtain 

 from mixing certain bodies. 



Pathology confirms our conclusion respecting these higher func- 

 tions of the cerebrum. Loss of cerebi-al substance, in man, is followed 

 by a weakening of the intellectual powers. They make a very childish 



