94 BRAINS OF RATS AND MEN 



quietly in apparent stupor, at other times it is restless 

 and keeps moving about. 



Rogers (191 6) has restudied these phenomena with 

 more exact anatomical control than has usually been 

 employed, and he concludes that this decerebrate 

 restlessness is due to the lack of the normal inhibi- 

 tions from the hemispheres acting on the lower reflex 

 centers. Further analysis shows that it is only inhibi- 

 tory reactions arising from external stimuli which are 

 lacking; those arising from visceral internal stimuli 

 are still operating. If the bird is kept well fed and 

 watered the restlessness will not appear. This rest- 

 lessness, in short, is correlated with hunger contrac- 

 tions of the digestive tract or other visceral activities. 

 Rogers says, ''When the hemispheres are gone, in- 

 hibitory reactions to external influences are gone 

 but are still retained for intrinsic stimuli." 



With injury to the thalamus there is a marked 

 change in the behavior and interference with temper- 

 ature regulation and other visceral functions. This 

 suggests that the thalamus is more important for 

 visceral correlations than are the cerebral hemi- 

 spheres. The birds remain quiet and cannot care for 

 themselves, starving to death in the midst of plenty 

 unless artificially fed (Rogers, 191 9). In these birds 

 the temperature of the body fluctuates with that of 

 the cage and at ordinary room temperatures the 

 condition is as described above; but if the room tem- 

 perature is raised so as to bring the body temperature 



