LoESER, Functions of the Frogs Brain. 361 



jumping, in a position at right angles to the direction in which it started. The 

 rotating table reactions were normal in both directions. The abdominal respira- 

 tion remained weakened on the homonymous side during the fifteen days follow- 

 ing the operation ; after which the post-mortem was made. The position of the 

 body, head and legs had gradually improved at the end of the first week so that 

 they were almost normal. From that time until the fifteenth day no further 

 changes were observed in these or in the unskilled and weak action of the homony- 

 mous limbs. The homonymous eye remained permanently constricted. 



XIX. A unilateral excision of the middle third of the medulla, including 

 the origin of the vagus group, abolished abdominal respiration on that side but 

 left a weakened croak reflex. The pupil of the homonymous eye was contracted, 

 otherwise the eyes appeared normal. The position of the head, legs and body, 

 and also the locomotion agreed with those noted under operation XVIII. The 

 rotating table reactions were normal and no rotary movements around the sagit- 

 tal axis were exhibited. The croak reflex was quite normal two weeks after the 

 operation. 



XX. Bilateral excision of the middle third of the medulla, including the 

 origin of the vagus groups abolished the croak reflex, turn-over reflex, and the 

 abdominal respiration on both sides. The hea»t, though beating strongly ten 

 minutes after the operation, became quite feeble two hours later and stopped at 

 the eighth hour after the operation. The respiratory movements of the nares 

 and mouth remained bilaterally present, increased very much in rate and force 

 and exhibiting asphyxia symptoms toward the end. It was impossible to keep 

 these animals alive longer than eight or twelve hours even when the water sur- 

 rounding them was frequently changed. After this operation a complete inver- 

 sion of the stomach and oesophagus, with prolapsus into and even outside of the 

 mouth occurred. The pylorus was the most anterior portion of the prolapsus. 

 I placed a dead fly on it and was interested in seeing it surrounded by slow 

 peristaltic movements. The pancreas, stomach, duodenum, and the adjoining 

 small intestine were also involved in the prolapsus. The stomach was distended 

 to twice its normal size. The peculiar position of the head noticed after the 

 different operations on the medulla was most conspicuous after this operation. 

 The head pointed into the ground and formed an obtuse angle with the body. 

 The urostyle was always less prominent after medulla injury. 



XXI. Excision of everything anterior to the spinal cord abolished the 

 respiratory movements, sense of equilibrium, eye, sight, croak, swallowing, heart, 

 and the turning-over reflexes. A stimulus was immediately answered by co-or- 

 dinated movements. It was answered sooner and with greater certainty than 

 when the higher portions of the brain were intact. The heart action gradually 

 faded away during the five hours following the operation. 



XXII. The excision of everything down to and including the anterior por- 

 tion of the spinal cord almost to the origin of the brachial plexus caused all of the 

 deficiency phenomena enumerated under operation XXI and in addition caused 

 the co-ordinated movements to fade away. They failed as soon as the anterior 

 limbs were incapable of supporting the body and helping the posterior limbs in 

 their efforts. 



