368 Journal of Comparative Neurology and Psychology. 



movements, namely those of the seventh, ninth, and tenth nerves, 

 and indicates that the narial and oral respiratory apparatus inner- 

 vated by the seventh and ninth, can continue their respiratory 

 movements independently of those of the abdominal ; moreover, 

 that no appreciable crossing of the efferent fibers of these ganglia 

 takes place. Furthermore, it corroborates the result found after 

 unilateral excision of the medulla, namely, that the croak ganglia 

 are located in the origin of the vagus group and are functionally 

 independent, although probably closely connected with one 

 another by association fibers. 



The excision of everything anterior to the spinal cord cor- 

 roborates a multitude of facts found in previous operations, and 

 proves that co-ordinated movements do not cease with the re- 

 moval of all the nervous structures anterior to the spinal cord. 

 It moreover shows that apparently some inhibitory influence is 

 taken away from the spinal cord with the removal of the struc- 

 tures anterior to it. 



My experimental results on the medulla agree with Schra- 

 der\ who states that frogs cease to catch flies if the optic 

 thalami are injured ; that the reactions on the rotating table are 

 reflex in character, the stimulations acting upon the semi- 

 circular canals and passing to the centre by the acoustic nerve ; 

 that frogs with injured medulla show a loose position of the 

 feet when resting, and that their heads point toward the ground. 

 Furthermore, that the medulla, down to the calamus scriptorius 

 may be removed in the frog without destroying co-ordinated 

 movements and that centres for respiratory movements, swal- 

 lowing and croaking are in the medulla. My observations also 

 corroborate Schrader's statement that after lesion behind the 

 vagus group there is often complete inversion of the stomach 

 and oesophagus, accompanied by prolapsus into the mouth, and 

 that the frog after section of the medulla even behind the 

 trigeminus group is still able to turn over on the ventrum when 

 placed on its dorsum. Schrader also states that if the section 



' Schrader, M. Pfluger's Archiv, 41, 75, iJ 



