132 Till-; NKRYolS SYSTEM A.ND ITS CONSKKVATK >N 



quiring new impressions \vliicli can furnish grounds of 

 ((induct. 



The removal of the cerebrum from a mammal without 

 causing the immediate death of the animal might well 

 seem an incredible feat of surgery. Nevertheless, it has 

 succeeded in a number of cases. The most celebrated 

 of these has been the one which is referred to as Goltz's 

 dog. By three carefully conducted operations the entire 

 mass of the cerebral hemispheres and, unintentionally, 

 somewhat more of the brain was broken up and washed 

 away. The dog was kept alive and narrowly observed 

 for a year and a half after the final operation. It was 

 then killed and the autopsy showed the thoroughness of 

 the destruction. Its health and .strength had been de- 

 clining for some time before it was sacrificed. 



The decerebrate dog afforded a general confirmation of 

 the inferences drawn from the pigeon. It was idiotic, 

 but not crippled in any department of its mechanical 

 activities. A noteworthy fact was that it was restless 

 rather than sluggish. Its aimless rovings supported the 

 opinion quite widely held that an important function of 

 the cerebrum is to inhibit the action of the lower brain 

 centers. Sometimes the dog appeared to sleep, but. if 

 we are right in our interpretation, its waking was not to 

 consciousness, but only to somnambulism. It showed no 

 fear or affection. It would snap at the hand of a tor- 

 mentor, but only under the direct stimulus of provocation: 

 it would not harbor a grudge against him. 



Concerning the human being, of course we do not have 

 evidence from deliberate experiment, but we have tin- 

 facts in a vast number of clinical cases. A surprising ami 

 instructive one lias been reported quite recently. I^ding-ei- 

 and Fischer' have described the condition of a defective 

 child that died of tuberculosis when nearly four years old. 

 It had made no appreciable progress in acquiring new 

 reactions from the day of its birth. It usually lay in 

 apparent .-lerp. seemed to be blind, and could not be said 

 \ivliiv f. (I. gcs. Physiologic, I'.ii:;, clii, .",:;.">. 



