The Dawn of Mind 235 



pacities, but relatively slow to learn, and the "big-brain" type, 

 with a relatively poor endowment of specialised instincts, but 

 with great educability. The ''little-brain" type finds its climax 

 in ants and bees; the "big-brain" type in horses and dogs, ele- 

 phants and monkeys. And of all animals monkeys are the quick- 

 est to learn, if we use the word "learn" to mean the formation 

 of useful associations between this and that, between a given sense- 

 presentation and a particular piece of behaviour. 



The Case of Sally 



Some of us remember Sally, the chimpanzee at the "Zoo" 

 with which Dr. Romanes used to experiment. She was taught to 

 give her teacher the number of straws he asked for, and she soon 

 learned to do so up to five. If she handed a number not asked 

 for, her offer was refused; if she gave the proper number, she 

 got a piece of fruit. If she was asked for five straws, she picked 

 them up individually and placed them in her mouth, and when 

 she had gathered five she presented them together in her hand. 

 Attempts to teach her to give six to ten straws were not very- 

 successful. For Sally "above six" meant "many," and besides, 

 her limits of patience were probably less than her range of com- 

 putation. This was hinted at by the highly interesting circum- 

 stance that when dealing with numbers above five she very 

 frequently doubled over a straw so as to make it present two ends 

 and thus appear as two straws. The doubling of the straw looked 

 like an intelligent device to save time, and it was persistently re- 

 sorted to in spite of the fact that her teacher always refused to 

 accept a doubled straw as equivalent to two straws. Here we 

 get a glimpse of something beyond the mere association of a 

 sound "Five" and that number of straws. 



The Case of Lizzie 



The front of the cage in which Professor Holmes kept Lizzie 

 was made of vertical bars which allowed her to reach out with 

 her arm. On a board with an upright nail as handle there was 



