THE NERVOUS SYSTEM 493 



removed, she could still stand up, but could only move forwards, 

 backwards, and turn with great difficulty. 



Injury to one cerebral peduncle in the rabbit was found by Longet 

 to lead to menage movements towards the opposite side ; but if the 

 peduncle were cut through, the movements did not occur. Colin 

 found that menage movements were performed by the horse when 

 a cerebral peduncle was injured. . He pricked the left peduncle, and 

 observed that the head was at once carried to the right, and the 

 neck and body bent, so that the muzzle became applied to the flank, 

 and sometimes to the thigh, as if the animal were bent in halves ; 

 the limbs were gathered in a bunch under the body, and the animal 

 rotated on a small pivot. When turning, it frequently fell, but the 

 body still remained curved ; when raised, the circular movements 

 were repeated. The horse could go backwards, but could neither 

 advance nor turn to the left. 



Colin destroyed the corpus callosum, and observed that he pro- 

 duced neither pain nor convulsions. Longet cut into it throughout 

 its length in young horses and young rabbits, and found there was 

 no sign of pain. The animals remained standing, but could walk 

 or run about if made to. Colin repeated the above experiment on 

 two horses. Both remained standing for a short time ; one then fell 

 backwards after some movement of the muscles of the eyeball ; the 

 other showed great muscular weakness, and fell on his side. There 

 were no convulsions in either case. 



All these observations by Colin were made before anything 

 was known of the function of the cerebrum in connection with 

 skeletal muscles. The crossed nature of the pyramidal tract in 

 these animals was clearly proved, and the great independence 

 of the spinal cord in bo vines demonstrated. 



Goltz removed both cerebral hemispheres, step by step, in a dog, 

 and succeeded in keeping the animal alive for eighteen months. 

 It became a most interesting psychical study. The animal was 

 a mere reflex machine. It could see, but not comprehend ; it 

 would show signs of hunger, eat when the nose was brought in 

 contact with the food, but could not recognise food placed near 

 it. After the paralysis succeeding the operation had passed 

 away, the dog could walk slowly and stupidly with its head down. 

 It would growl or bark, turned its head to the spot if stimulated, 

 but did not bite. The face was expressionless, and the tail was 

 never wagged. It rejected food of a disagreeable nature, such 

 as meat soaked in a solution of quinine. No matter how hungry, 

 this was refused, though the gustatory centres had been removed. 

 The animal slept, but did not dream. She exhibited no sexual 

 excitement or oestrum. Memory, emotions, and the capacity to 

 learn were absent ; anger was a prominent feature. Goltz's dog 

 exhibited it every day for eighteen months each time she was fed. 



A point in the history of this dog has now been reached which 

 is of extraordinary veterinary interest. The animal in its 

 roaming on one occasion wounded its hind-foot ; it was then 



