AND PHYSIOLOGY. 



347 



and was employed during his waking hours in this business. 

 Hence his sleep was very solid, and he was roused by no or- 

 dinary sound, but his comrades amused themselves by whis- 

 pering the word " signal" in his ear, when he was at once 

 aroused and fit for duty. 



621. Functions of the Cerebellum. — The Cerebellum 

 does not seem to be in any manner directly connected with 

 the phenomena of mind. But it seems designed simply for 

 the purpose of combining the actions of different muscles, or 

 presides over the coordination of voluntary muscular move- 

 ments, as in walking, speaking, and similar actions requiring 

 several sets of muscles to be used at tye same instant. Ac- 

 cordingly in animals, which possess the greatest variety of 

 movements, we find the largest cerebellum. 



622. Effects when Removed from Animals —The Con- 

 trolling Power of Muscular Motions. — When this organ 

 has been removed from some of the lower animals, it was found 

 that they could not control their movements. When laid 

 down they could not recover their erect posture, and when 

 threatened with a blow, they in vain endeavored to avoid it. 

 Another phenomenon attending a wound, or removal of both 

 sides of the cerebellum, was the motion of the animal in a 

 backward direction, and the rolling from side to side on the 

 longitudinal axis of the body, and keeping up this motion 

 uninterruptedly, for several hours, at the rate of sixty revolu- 

 tions per minute. In some men who have been afflicted with 

 a disease of this organ, an unsteadiness of gait has been ob- 

 served, which gives additional strength to the belief that the 

 Cerebellum is the regulator of muscular movements, 



623. Functions of the Medulla Oblongata — The Me- 

 dulla Oblongata seems to have for its function the sending of 

 nervous power to the muscles of respiration and swallowing, 



621. Does the cerebellum control the phenomena of mind? What are its functions' 

 622. What effects does its removal cause in animals ? How does a disease of it affect 

 men? 623. What operations are controlled by the medulla oblongata ? 



