360 Journal of Comparative Neurology and Psychology. 



tion, a slight movement of the head, as previously noted, was seen during and 

 after rotation of the table ; and sometimes a circular movement of the body in 

 clock-wise direction, after rotation of the table. While rotating the table in anti- 

 clock-wise direction, no head movement was seen, but a slight circular move- 

 ment of the body in anti-clock-wise direction appeared after rotating the table. 



Abdominal respiration ceased during rotary movements, but subsequently it 

 was resumed on the operated side. Fifteen days after the operation, by means 

 of vivisection under very slight anaesthesia and exposure of both lungs, I ob- 

 served that only the crossed lung respired. In the meantime, the characteristic 

 position of body and head had but slightly improved, and was as pronounced as 

 ever when the frog was excited. The rotary movements around the sagittal 

 axis, which began about ten minutes after the operation, at the end of two days 

 had diminished, but were aroused by the slightest stimulation, even by sight or 

 movement, on the rotating table toward the crossed side ; they could also be in- 

 hibited in part or completely by touch and movement on the rotating table toward 

 the homonymous side. 



After three days the position of head and body was temporarily normal and 

 the superflexed or superextended legs respectively were also temporarily brought 

 back to their normal position. After five days the rotary movements showed 

 themselves only when the frog was jumping ; the animal usually made a com- 

 plete circuit around its sagittal axis during the jump. Three days later the frog 

 sometimes landed on the dorsum after a jump ; and the croak reflex became 

 stronger. By the tenth day the rotary movement was manifested by the fact 

 that the animal landed on the side after a jump. The jumps never became as 

 strong and skilled as before the operation. The position of the head, body and 

 legs had improved ten days after the operation, although still quite abnormal. 

 The position of the eyes and the movements of the homonymous eye and nicti- 

 tating membrane had improved very little during the fifteen days following the 

 operation. In fact, no appreciable improvement was noticeable after ten days. 

 The defects were least noticed while the animal was at rest. 



XVII. Unilateral excision of the right side of the medulla, anterior to tiie 

 origin of the vagus group left the croak reflex and abdominal, narial, and oral 

 respiration movements intact on both sides. It caused rotatory movements around 

 the sagittal axis, the peculiar flat position of the front part of the body and head, 

 the characteristic position of the limbs, the eye reflex, the position of the eyes, 

 the movements of the homonymous eye and nictitating membrane and the ro- 

 tating table reactions exactly as stated in operation XVI. The apnoic pauses in 

 the abdominal respiration after rotary movements around the sagittal axis, were 

 less pronounced. 



XVIII. Unilateral excision of the right half of the medulla from a point 

 posterior to the origin of the vagus group down to the calamus scriptorius, left 

 the croak reflex intact. The abdominal respiration was slightly injured on the 

 homonymous side and intact on the crossed, as was proved by vivisection and 

 exposure of both lungs under very slight anaesthesia. The eyes were normal on 

 both sides, excepting that the pupil of the homonymous eye was extremely con- 

 tracted. The characteristic position of the body, head and legs was present in a 

 lesser degree than after operation XVII. The rotatory movements around the 

 sagittal axis were absent, but the animal landed on the homonymous side, after 



