362 Journal of Comparative Neurology and Psychology. 

 Discussion and Conclusions. 



The removal of one or both cerebral hemispheres proved 

 that the motor centres of the cerebral cortex of the frog are of 

 minor importance and the sensory centers scanty. The fact 

 that a frog deprived of both cerebral hemispheres caught flies 

 proves that the reflex connection of the optic nerve with the in- 

 nervation of the snapping and swallowing apparatus is not lo- 

 cated in the cerebrum. Although Goltz^ observed a loss of 

 muscular sense for several days in his dog deprived of both 

 cerebral hemispheres, no such defect was visible in my frogs 

 from which both cerebral hemispheres had been removed. The 

 decrease in voluntary movement and sensitiveness to touch which 

 existed for a few days, I attribute to disruption of association 

 fibers and not to destruction of motor or sensory areas. 



In connection with my results, I may mention that Bickel,' 

 using chemical agents, and both kinds of electrical stimulations, 

 was unable to produce paralysis in the pigeon or frog unless 

 the current was excessively strong. Bickel further concludes 

 that in turtles the cerebrum does not regulate movements but 

 has a motion-inducing (bewegungsanregend) influence. Adam- 

 KiEWicz^ also states that an animal deprived of the cerebral 

 cortex carries on all bodily movements normally if it is arti- 

 ficially induced to perform them. Bary* determined that the 

 new-born child lacks the principal group of motions which are 

 controlled by the will. Moreover, Schrader'^ demonstrated 

 that frogs deprived of the cerebrum behave, after several days, 

 like normal frogs, and Goltz showed that his dog deprived of 

 the cerebrum was essentially normal, excepting that the higher 

 cerebral functions — memory, deliberation, intelligence, pleasure 

 and envy — were absent. 



1 Goltz, F. PJlugcrs Arckiv, 51, 570, 1892. 



* Bickel, A. PJluger''s Archiv, 72, 190, 1S9S, and Archiv fur Anatomie 

 und Physiologic, 52, 1 901. 



3 Adamkiewicz, a. Neurologischcs Zentralblatt, 22, 12, 546. 



* Bary, a. Archiv filr Anatomic tmd Physiologic, 341, 1898. 

 ^ SCHRADER, M. PJOigcr's Archiv, 41, 75, 1887. 



