THE BRAIN 125 



deliberate experiments upon the human brain, but nature 

 makes many which are at once deplorable and in- 

 structive. We are often compelled to see the havoc 

 wrought by hemorrhages, tumors, and other agencies 

 which injure the intricate mechanisms of the cerebrum. 

 On the whole, the collected data confirm the belief that 

 we have here the physical apparatus of intelligence. 



In all probability the human cerebrum, besides 

 representing an advanced type of outfit for recording 

 individual happenings, has taken over certain functions 

 which in the dog are subserved by other parts of the 

 brain. We have noted the use of the eyes in main- 

 taining equilibrium. As a rule this is a subconscious 

 service and we have seen that in the decerebrate pigeon 

 as well as in the dog it continues in the absence of a 

 cerebrum. It is not likely that it could so continue in 

 man. When certain local damage is suffered by the 

 human cerebrum there is total blindness so far as can 

 be determined; no subconscious guidance in locomotion 

 is afforded by the eyes. 



Quite recently there was published a description of a 

 defective child that lived four years before it was 

 happily released by disease. It was found postmortem 

 to have no cerebrum at all, the space being filled with 

 fluid. There had been no appreciable progress in ac- 

 quiring new reactions from the day of birth. The child 

 seemed blind and generally lay passive as though sleep- 

 ing. No certain token of consciousness had been recog- 

 nized. This dreadful case lends weight to the usual 

 view: that all individual gains in adjustment to the 

 environment are conditioned by the organization of 

 the cerebrum. 



Localization. Granting that intelligent activities have 

 their physical accompaniments in the cerebrum, what 

 can be said of the distribution of these processes? This 

 has proved a fascinating and difficult question. For 

 more than a century it has been before physiologists and 

 physicians. In 1830 the belief in precise localization of 



