PLATE II 



FIGS. 1 to 14. The extent of the lesions in animals which retained the habit of 

 the simple maze after cerebral destruction. The numbers of the figures corre- 

 spond to the numbers of the experiments under which the animals are described. 

 In figures 10, 11, and 12 the striated areas show the extent of the second operation. 



FIGS. 34 to 39. The extent of the lesions in animals which formed simple 

 habits after operation. The solid black areas are those in which the cortex was 

 completely absorbed. The dotted areas are those in which the cortex was proba- 

 bly not functional as a result of the destruction of its descending fibers. 



136 



