244 COMPARATIVE PHYSIOLOGY OF THE BRAIN 



that the animal without cerebral hemispheres shows 

 the difference between sleeping and waking. 



The great difference between the normal male 

 pigeon and the pigeon that has lost its cerebral hemi- 

 spheres is shown forcibly by the following facts : 

 During the period of heat the male pigeon courts the 

 female with cooing, but if a female pigeon is placed 

 before the cooing male whose hemispheres have been 

 removed, it remains unheeded. This entire lack of 

 memory is the chief point in which the animal without 

 cerebrum differs from the normal animal. " For the 

 former everything is only a mass in space, it moves 

 aside for every pigeon or attempts to climb over it, 

 just as it would in the case of a stone. All authors 

 agree in the statement that to these animals all objects 

 are alike. They have no enemies and no friends. 

 They live like hermits no matter in how large a com- 

 pany they find themselves. The languishing coo of 

 the male makes as little impression upon the female 

 deprived of its cerebrum as the rattling of peas or the 

 whistle which formerly made it hasten to its feeding 

 place. Neither does the female show interest in its 

 young. The young ones that have just learned to fly 

 pursue the mother, crying unceasingly for food, but 

 they might as well beg food of a stone " (4). 



Taking all the reactions of the pigeon without 

 cerebral hemispheres together, it seems to me that 

 the conclusion may be drawn that loss of the cerebral 

 hemispheres causes the loss of the associative mem- 

 ory. Inherited reactions remain after the loss of the 



