X BRAINS OF RATS AND MEN 



indebted for permission to reproduce Figures 8, 25, 

 and 28; to W. B. Saunders Company for Figures 3 

 and 4; and to the Field Museum of Natural History 

 for Figures 32 and 23- Parts of the text have been 

 read by several of my colleagues, from whom many 

 valuable suggestions have been received. Others, too 

 numerous to mention, have given less direct, though 

 not less valuable, assistance. 



I am especially indebted to Professor Lashley, 

 who has read parts of the text; and in numerous 

 conferences he has generously given me the benefit of 

 his wide experience and critical thinking. While the 

 conclusions which we have reached are not in perfect 

 accord, we agree that this arises largely from differ- 

 ence in point of view and emphasis. But not wholly 

 so; there are some questions that seem fundamental 

 which I believe cannot be resolved by the over- 

 simplified formulations now current in the field of 

 "objective psychology." 



These problems are here approached from the 

 biological side and with biological technique. The 

 aim is to limit the discussion to that field which can 

 properly be cultivated with the methods of natural 

 science, though I would extend the confines of this 

 field much further than many of my colleagues seem 

 to consider permissible. 



In particular, the belief that mind or consciousness 

 as introspectively experienced is a natural phenome- 

 non which cannot be neglected in a total view of 



