LoESER, Functions of the Frog s Brain. 359 



terior to the origin of the vagus group; the limbs of the crossed side — especially 

 the posterior one — were abnormally extended and abducted, locomotion was al- 

 ways towards the homonymous (operated) side. The spine was slightly bent, 

 concave towards the homonymous side in the thoracic region. Though the forced 

 position of the limbs of the crossed side and the curved state of the spine im- 

 proved considerably in one week after the operation, yet they, together with the 

 squatted position of the body, and locomotion, remained quite characteristic two 

 and a half months after the operation. 



XV. Bilateral excision of everything anterior to the medulla leaves the 

 croak, the turning-over, the swallowing and heart-action reflexes, the sense of 

 equilibrium and respiration intact. The croak and turning-over reflex could 

 hardly be elicited during the first few days, but they were normal after one week. 

 If the anterior portion of the medulla was also removed, apnoic pauses alternated 

 with periods of normal respiration. During such a pause, the animal remained 

 quite motionless for about five minutes. To avoid injury to the medulla, it is 

 best to burn off the cerebellum after everything anterior to it has been removed. 



XVI. After unilateral excision of the right side of the medulla anterior to 

 the calamus scriptorius abdominal respiratory movements on the homonymous 

 side stopped, whereas the narial and oral as well as swallowing movements were 

 still normal. 



The animal assumed a flat position and the head and homonymous side were 

 lower than other parts of the body. The legs on the crossed side, especially the 

 posterior one, were far extended and abducted ; and the homonymous legs, es- 

 pecially the front one, were superflexed and adducted. Forced rotary move- 

 ments around the sagittal axis of the body and towards the homonymous side 

 were present as the sole movements on land and in water. The eye reflex to 

 pressure on the homonymous side of the body was abolished, but was normally 

 present on the crossed side. The crossed eye was turned up and outward, and 

 the homonymous one, down and inward. The homonymous eye was turned up 

 synchronously with inspiration, and down with expiration. The nictitating 

 membrane of this eye was evidently beyond the control of the frog since it cov- 

 ered the eye, especially when it moved downward. The spine and neck were 

 curved as after unilateral cerebellar excision and tremors were present in the 

 limbs on both sides, but were more pronounced in the weaker legs of the 

 homoymous side. A weakened croak reflex still persisted. 



These defficiencies were almost entirely confined to the homonymous side. 

 Sight was perfect on the crossed side, and although the eye reflex to pressure was 

 abolished on the homonymous side, the animal still saw with this eye. The ro- 

 tating table reactions were complex and will therefore be described in greater de- 

 tail. One half to five hours after the operation the animal did not react on the 

 rotating table with either head or body movements. Twenty-four hours later, 

 when the table was rotated in a clock-wise direction, i. e., towards the operated 

 side of the frog, the animal held its head in anti-clock-wise direction during ro- 

 tation ; after rotation, the head was brought back beyond the sagittal axis of the 

 body in a clock-wise direction. On rotating the table in anti-clock-wise direc- 

 tion, no head movement was produced during and after rotation, but a slight 

 circular movement of the body in anti-clock-wise direction was seen after rota- 

 tion. Forty-eight hours afterward, while rotating the table in a clock-wise direc- 



