PLATE III 



FIG. 17: Lesion in the control animal in which there was no operation on the 

 brain. 



FIGS. 18 and 19. Lesions in the control animals after operation on the tem- 

 poral lobes. 



FIGS. 20 to 24. The extent of the lesions in the animals which retained the 

 inclined-plane box habit after operation. 



FIGS. 25 and 26. The extent of the lesion in the animals which showed a doubt- 

 ful retention of the habit. 



FIGS. 27 to 33. The extent of the lesion in the animals which lost the inclined- 

 plane box habit after operation. 



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