CHAPTER VII 



THE EVOLUTION or THE HUMAN INTELLECT l 



To the intelligent man with an interest in human nature 

 it must often appear strange that so much of the energy of 

 the scientific world has been spent on the study of the body 

 and so little on the study of the mind. ' The greatest thing 

 in man is mind/ he might say, 'yet the least studied/ Es- 

 pecially remarkable seems the rarity of efforts to trace the 

 evolution of the human intellect from that of the lower ani- 

 mals. Since Darwin's discovery, the beasts of the field, 

 the fowl of the air and the fish of the sea have been ex- 

 amined with infinite pains by hundreds of workers in the 

 effort to trace our physical genealogy, and with consummate 

 success ; yet few and far between have been the efforts to 

 find the origins of intellect and trace its progress up to hu- 

 man faculty. And none of them has achieved any secure 

 success. 



It may be premature to try again, but a somewhat ex- 

 tended series of studies of the intelligent behavior of fishes, 

 reptiles, birds and mammals, including the monkeys, which 

 it has been my lot to carry out during the last five years, has 

 brought results which seem to throw light on the problem 

 and to suggest its solution. 



Experiments have been made on fishes, reptiles, birds and 

 various mammals, notably dogs, cats, mice and monkeys, 

 to see how they learned to do certain simple things in order 



1 This chapter appeared originally in the Popular Science Monthly, Nov., 

 1901. 



282 



