Animal Intelligence 153 



After careful consideration of all the evidence that 

 we have been able to find, we personally remain un- 

 convinced that there is at present any satisfactory 

 instance of the transmission of a particular modifica- 

 tion even in a representative degree. But others have 

 come to a different conclusion, and, as we cannot 

 prove a negative, we think that the Lamarckian door 

 should be kept open. We wish to call attention to a 

 few cases which suggest the desirability of keeping 

 an open mind. 



HABIT FORMING 



The word "habits" is often used to include all the 

 ways or behavior of animals, as when we speak of the 

 habits of monkeys, or the habits of rooks, or the 

 habits of spiders. But this usage is too wide to be 

 profitable. For many of these "habits" are the expres- 

 sion of inborn ready-made aptitudes, such as those 

 which are called instinctive ; others, especially in the 

 big-brained animals, are expressions of genuine in- 

 telligence which controls every step ; and others are 

 the result of individual habituation in the perform- 

 ance of an oft-repeated routine, for which, however, 

 there was no precise hereditary pre-arrangement of 

 nerve-cells and muscle-cells. 



Miss Cunningham tells the following story of the 

 young gorilla whose kind teacher she was. One day 

 when a piece of fillet-beef came in from the butcher's, 

 she cut off a tiny, rough piece and offered it to 

 "John." He gravely handed it back, and gently tak- 

 ing her hand pressed it against a soft, juicy piece. 



