CEREBELLUM. 431 



after experimentally injuring or destroying this part of the brain. 

 If the cerebellum be exposed in a living pigeon, and a portion of 

 its substance removed, the animal exhibits at once a peculiar un- 

 certainty in his gait, and in the movement of his wings. If the 

 injury be more extensive, he loses altogether the power of flight, 

 and can walk, or even stand, only with great difficulty. This is not 

 owing to any actual paralysis, for the movements of the limbs are 

 exceedingly rapid and energetic ; but is due to a peculiar want of 

 control over the muscular contractions, precisely similar to that 

 which is seen in a man in a state of intoxication. The movements 

 of the legs and wings, though forcible and rapid, are confused and 

 blundering ; so that the animal cannot direct his steps to any par- 

 ticular spot, nor support himself in the air by flight. He reels and 

 tumbles, but can neither walk nor fly. 



Fig. 142. 



PIGEON, AFTER REMOVAL OF THE CEREBELLUM. 



The senses and intelligence at the same time are unimpaired. It 

 is extremely curious, as first remarked by Longet, to compare the 

 different phenomena produced by removal of the cerebrum and 

 that of the cerebellum. If we do these operations upon two dif- 

 ferent pigeons, and place the animals side by side, it will be seen 

 that the first pigeon, from whom the cerebrum only has been re- 

 moved, remains standing firmly upon his feet, in a condition of 

 complete repose ; and that when aroused and compelled to stir, he 



