NERVOUS CONTROL OF ANIMAL MOVEMENTS. 355 



attitude. The first turn, particularly when the lesion is old, is slower 

 and less regular ; the second is rapid and spasmodic. The first is the 

 consequence of the lesion, the second is the consequence of the regular 

 action of all the nervous centres ; and, the better to express this thought, 



2 





s 



a 

 o 



3 

 ft 



we may say that, in an animal from which have been taken only the 

 cerebral lobes, we might obtain a movement of rotation if, as soon as 

 the animal is on his fore-feet, we turn him on his back ; external inter- 

 ference would replace in this case the action produced by lesion of the 

 pons Varolii. 



