GENERAL PHYSIOLOGY OF THE CEREBRUM. 179 



of these animals is that in them the cerebrum is the place in which 

 the memory records are stored, and that when it is removed the 

 actions of the animal when stimulated become much more direct 

 and predictable, since the stimulus awakens no associations with 

 past experiences. The complete removal of the cerebrum in mam- 

 mals is attended with more difficulty. When taken out at once 

 by a single operation the animal survives but a short time and 

 the permanent effects of the operation cannot be detected. Goltz,* 

 however, has succeeded, in dogs, in removing by a peculiar operation 

 all of the cerebral cortex. The operation was performed in sev- 

 eral successive stages with an interval of several months between. 

 In the most successful experiment the animal was kept alive for 

 a year and a half and the postmortem examination showed that 

 all of the cortex had been removed except a small portion of the 

 tip of the temporal lobe, and this latter, since its connections with 

 the other parts of the brain had been destroyed, was, of course, 

 functionless. In addition, a large part of the corpora striata and 

 optic thalami and a small portion of the midbrain had been re- 

 moved. The behavior of this animal was studied carefully. After 

 the immediate effects of the operation paralysis, etc. had disap- 

 peared the animal moved easily ; in fact, showed a tendency to keep 

 moving continually. There was no permanent paralysis of the so- 

 called voluntary movements. He answered to sensory stimuli of 

 various kinds, but not in an intelligent way. If, for instance, a 

 painful stimulus was applied to the skin, he would growl or bark, 

 and turn his head toward the place stimulated ; but did not attempt 

 to bite. No caressing could arouse signs of pleasure, and no 

 threatening signs of fear or anger. Like the pigeon, the most con- 

 spicuous defect in the animal was a lack of intelligent response, 

 that is, the responses to sensory stimuli were simple, and evidently 

 did not involve complex associations with past experiences. His 

 memory records, for the most part, had been destroyed. Goltz 

 records that when starved he showed signs of hunger, and that 

 eventually he learned to feed himself when his nose was brought 

 into contact with the food, although he was not able to recognize 

 food placed near him. He would reject food with a disagreeable 

 taste. When sleeping he gave no signs of dreaming, differing in 

 this respect from normal dogs. 



Localization of Functions in the Cerebrum. When the 

 belief was established that the cerebrum is the organ of the higher 

 psychical activities there arose naturally the question whether dif- 

 ferent parts of the cortex have different functions corresponding 

 to the various faculties of the mind, or whether the cerebrum is 

 functionally equivalent throughout, in the same sense, for instance, 

 * Goltz, "Archiv f. die gesammte Physiologic," 51, 570, 1892. 



