CEREBRAL HEMISPHERES AND MEMORY 245 



cerebrum, but that which is acquired by the activity 

 of memory during the life of the individual is lost 

 forever. 



In order to emphasise this loss of memory after ex- 

 tirpation of the hemispheres, we will quote the follow- 

 ing observation made by Schrader on a falcon. The 

 falcon, as everyone knows, is a good hunter. Schrader 

 placed some mice, and a falcon from which the hemi- 

 spheres had been removed in the same cage. Every 

 time that a mouse moved the falcon jumped on it and 

 caught it in its claws, if the movement occurred with- 

 in its field of vision. The normal falcon in such cases 

 devours the mouse, but for the falcon without cerebral 

 hemispheres the matter w r as at an end when the mouse 

 was caught. The activity of the associative memory 

 was lacking and the mouse was forgotten as soon as it 

 ceased to move. When the falcon moved, the mouse 

 escaped, but if the mouse moved again the process was 

 repeated. Any inanimate object that moved would, of 

 course, be caught in the same way. The falcon and 

 mice remained together until one day the mouse de- 

 voured the back of the living falcon. Deprived of its 

 memory the falcon was entirely defenceless (2). 



One disturbance takes place in animals that have 

 lost the cerebrum which does not belong in the same 

 class with disturbances of memory, namely, the inabil- 

 ity to take food unassisted. In frogs and, according 

 to Steiner's observations, also in fishes (5), the ability 

 to take food independently continues to exist after 

 excision of the cerebral hemispheres. Birds without 



