LoESER. Functions of tJic Frog s Brain. 373 



XIX. Unilateral excision of the right middle third of the medulla including the 

 origin of the vagus group. 



(a) Phenomena which showed no change from first to the fifteenth day — 



(') Abdominal respiration on the homonymous side is completely 



abolished. 

 (2) Pupil of this side is contracted. 



(b) Phenomina as observed after operation XVIII, 



(1) Position of head, legs, and body. 



(2) Defect in locomotion. 



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

 of the vagus group. 



(a) Abdominal respiration is abolished on both sides, also, the croak, turn- 



over, and swallowing reflex is gone. 



(b) The head points into the ground. 



(c) Urostylic prominence is gone. 



(d) Complete inversion of oesophagus and stomach with prolapsus outside of 



the mouth. 



(e) Heart becomes feeble two hours after operating. 



(f) Eight hours after operating, respiration of nares and mouth is exagger- 



ated, due to asphyxia. 



(g) Frogs died 8 hours after operating. 



XXI. Excision of everything anterior to the spinal cord. 



(a) Respiratory, croak, swallowing, heart-action, and turn-over reflexes are 



gone entirely. 



(b) Sense of equilibrium is lost. 



(c) Eye reflex and sight is lost. 



(d) Stimuli are answered sooner and with greater certainty than when higher 



portions of the brain are intact. 



(e) Heart action gradually ebbs away during the five hours which the frog 



usually lives after the operation. 



XXII. Excision of everything anterior to and including the anterior portion of 



the spinal cord almost down to the origin of the brachial plexiffe. 



(a) All phenomena of operation XXI. 



(b) Co-ordinated movements fade away during the first two to three hours 



after this operation. 



(c) Three hours after operating, the fore limbs cannot support the body 



any more. 



(d) The frog is usually dead five hours after the operation. 



