The Beginnings of Intelligence 123 



trine of the transmission of acquired characters, 

 which has come to be a very questionable biological 

 theory. But another and more, fundamental dif- 

 ficulty is revealed by recent work on the behavior 

 of lower organisms. If instinct were derived from 

 intelligence by a sort of mechanizing process we 

 should expect, as Whitman has urged in his criti- 

 cism of LewesV theory, to find intelligence domi- 

 nant in lower forms of life, and that acts which are 

 instinctive in the higher animals would be intelli- 

 gently performed by; the lower ones. The work 

 that' has been done on the behavior of lower or- 

 ganisms enables us to state with confidence that 

 such is not the case. In several large phyla of the 

 lower invertebrates there has not, as yet, been 

 demonstrated the least glimmer of intelligence ; and, 

 as we pass up the scale of life, intelligence grad- 

 ually supersedes instinct, not the reverse. We can 

 say with some degree of assurance that, however 

 the transition may have been effected, intelligence 

 has grown out of purely instinctive behavior. 



It is not possible, however, to fix, except with 

 the rudest approximation, the stage of evolution at 

 which intelligence makes its first appearance. The 

 transition from instinct to intelligence has been 

 made, in all probability, not once, merely, but sev- 

 eral times along different lines of descent. Intelli- 

 gence in the vertebrates doubtless arose independ- 

 ently from that of the insects, and the intelligence 

 exhibited here and there among the mollusks prob- 



