CENTRAL NERVOUS SYSTEM. 



707 



(see Fig. 201). A frog without its hemispheres is therefore capable of doing 

 several things apparently in a spontaneous way. Such frogs balance themselves 



D 



FIG. 201. Frog's brain; the parts in dotted outline have been removed: A, brain intact; B, cerebral 

 hemispheres removed ; C, cerebral hemispheres and thalami removed ; D, cerebellum removed ; E, two 

 sections through the optic lobes ; F, two sections through the right half of the bulb (Steiner). 



when the support on which they rest is slowly turned, moving forward or back- 

 ward as the case demands in order to maintain their equilibrium. In doing 



