CHAP. XI.] FUNCTIONS OF THR CEREBELLUM. 359 



riment than them. A skilful operator may remove the greater part 

 or the whole of the cerebellum without inflicting any injury on the 

 hemispheres or other parts. 



Flourens removed the cerebellum from pigeons by successive slices. 

 During the removal of the superficial layers there appeared only a 

 slight feebleness and want of harmony in the movements, without 

 any expression of pain. On reaching the middle layers an almost 

 universal agitation was manifested, without any sign of convulsion : 

 the animal performed rapid and ill-regulated movements ; it could 

 hear and see. After the removal of the deepest layers, the animal 

 lost completely the pow r er of standing, walking, leaping, or flying. 

 The power had been injured by the previous mutilations, but now it 

 was completely gone. When placed upon his back; he was unable 

 to rise. He did not, however, remain quiet and motionless, as 

 pigeons deprived of the cerebral hemispheres do ; but evinced an 

 incessant restlessness, and an inability to accomplish any regular or 

 definite movement. He could see the instrument raised to threaten 

 him with a blow, and would make a thousand contortions to avoid 

 it, but did not escape. Volition and sensation remained ; the power 

 of executing movements remained ; but that of co-ordinating these 

 movements into regular and combined actions was lost. 



Animals deprived of the cerebellum are in a condition very similar 

 to that of a drunken man, so far as relates to their power of loco- 

 motion. They are unable to produce that combination of action in 

 different sets of muscles which is necessary to enable them to assume 

 or maintain any attitudes. They cannot stand still for a moment ; 

 and, in attempting to walk, their gait is unsteady, they totter from 

 side to side, and their progress is interrupted by frequent falls. 

 The fruitless attempts which they make to stand or walk is suffi- 

 cient proof that a certain degree of intelligence remains, and that 

 voluntary power continues to be enjoyed. 



Rolando had, previously to Elourens, observed effects of a similar 

 nature consequent upon mutilation of the cerebellum. In none of 

 his experiments was sensibility affected. The animal could see, 

 but was unable to execute any of the movements necessary for 

 locomotion. 



Flourcns' experiments have been confirmed by those of Hertwig 

 in every particular, and they have been lately repeated with similar 

 results by Budge and by Longet. The removal of part of the cere- 

 bellum appears capable of producing the same vertiginous affection 

 which has been already noticed in the case of deep injuries to the 

 mesocephalo. After the well-known experiments of Majendie, of 



