ANATOMY AND PHYSIOLOGY OF THE BRAIN. 427 



Average. Highest. Lowest. 



Stallions, ... 61 65 56 



Mares, .... 61 66 58 



Geldings, ... 70 76 64 



The greater weight of the cerebellum in geldings is the 

 more remarkable, that the cerebrum of the stallion is on an 

 average heavier than that of the gelding. This tends the 

 more to remove the suspicion of fallacy in the comparative 

 examination. 



Flourens, Hertwig, Longet and others, have removed 

 the entire cerebellum of birds piecemeal, and found that 

 when the middle layers were reached, the movements be- 

 came violent and irregular, while after the removal of the 

 whole, all power of springing, flying, walking, or standing 

 was lost. Sight and hearing, with sensation, volition, and 

 memory, were still retained, and the bird would struggle 

 violently to escape from any loud noise or threatened blow. 

 It could no longer control and harmonize the action of its 

 muscles in its attempts to fly ; but fluttered and reeled as 

 if intoxicated. From these experiments Flourens inferred 

 that the cerebellum controlled and harmonized the various 

 muscular movements, while Foville, with quite as much 

 reason, attributes the symptoms to the loss of muscular 

 sense: 



Brown-Sequard calls both of these theories in question, 

 and insists that the want of harmony between the move- 

 ments depends not on the destruction of the cerebellum, 

 but on the irritation to which the neighbouring parts are 

 subjected. In support of this he adduces a case in which 

 the cerebellum was deeply wounded in the human subject, 

 notwithstanding which the man could still walk steadily, 

 and even ascend a ladder alone. 



He is further of opinion that the cerebellum controls to 



