372 Journal of Comparative Neurology and Psychology. 



(i6) Tremor on both sides ; but strongest on the homonymous side. 



(17) Weakness of muscles in proportion to tremor. 



(18) Sight is perfect on both sides, 



C. Twenty-four hours after operating. 



(la) Rotating the table in clockwise direction, i. e., toward the operated 

 side, the frog moves his head in anti-clockwise direction ; after 

 rotating, the head is brought back beyond the sagittal axis of the 

 body in clockwise direction. 



(lb) Rotating in anti-clockwise direction elicits no head movements ; but 

 a slight, circular movement of the body in an anti-clockwise di- 

 rection is noted after rotating the table. 

 (5) Is increased by the slightest stimulation. 



D. Two days after operating, 



(la) Same as after one day but in addition, sometimes a circular move- 

 ment of the body in clockwise direction after rotating the table, 

 (lb) Same as after one day. 

 (5) Diminishing. 



E. Three days after operating, 



(2), (3), and (4) were temporarily normal during short intervals while the 

 frog was resting. 



F. Five days after operating, 



(5) Frog rotates only when it attempts to jump. 



G. Six days after operating, 



(5) Frog, on jumping, sometimes lands on dorsum. 

 H. Ten days after operating, 

 (13) Is normal. 



(i)' (')> (3)) ^^'^ (4) ^rs still far from normal. 

 (5) On jumping, frog sometimes lands on dorsum and sometimes on 

 homonymous side. 

 I. No appreciable change in any symptoms from tenth to fifteenth day. 



XVII. Unilateral excision of the right side of the medulla anterior to the origin 

 of the vagus group. 



(a) The same phenomena as observed after operation XVI ; excepting that 



(b) Abdominal respiration is intact on both sides. 



(c) The croak reflex is normal immediately after the operation. 



(d) The bilateral apnoeic pauses in abdominal respiration, after rotating 



movements around the sagittal axis, are pronounced. 



XVIII. Unilateral excision of the right side of the medulla posterior to the 

 origin of the vagus group to the calamus scriptorius. 



Causes from first to fifteenth day — 



(i) Slight impairment of the abdominal respiration on the homonymous 

 side. 



(2) Contraction of pupil on the homonymous side. 



(3) Weakness of limbs on the homonymous side. 



(4) Position of legs, body and head as observed after operation XVI, 



but in a lesser degree. They improved during the first week but 

 did not regain normal. 



