598 LIFE : OUTLINES OF GENERAL BIOLOGY 



the appearance of the fruit. For about a fortnight this kind of lesson 

 was given once or twice a day, and Chim was much interested and 

 very appreciative. The hope was that the ape would learn to say 

 "ba, ba!"; but it never did. Another method was to hang in 

 the cage an apparatus loaded with pieces of banana, which were 

 delivered to the chimpanzee in succession whenever the experi- 

 menter said "co, co!" But Chim did not get beyond "certain 

 slight and unconvincing imitations of attempts to make sounds 

 when facing the apparatus." 



.\nother educational apparatus consisted of a board on which 

 was a small box hinged on one side and provided with a spring, 

 which when released would raise the box and disclose a banana. As 

 the box had a wire-mesh cover, this method had the advantage that 

 the pupil could see the fruit. Prof. Yerkes took the contraption 

 into Chim's cage, secured his attention, and made the sound "na, 

 na!" distinctly and emphatically a few times, thereupon releasing 

 the spring and disclosing the prize. Sometimes he would begin to 

 eat the banana to intensify the ape's interest. This was done over 

 and over again, but the chimpanzee never learned to say "na, na!" 

 The only kind of lesson in this direction that had any positive result 

 was that the ape learned, as a dog will learn, to utter a particular 

 sound oj its own when it wanted to get food. 



Chimpanzees are so intelligent and sympathetic that we cannot 

 accept the philosopher's remark that animals would speak if they 

 had anything to say. What, then, is the reason for their relative 

 reticence, for their not advancing from words to language? Is there 

 any answer but that the ape-brain has not reached the degree of 

 differentiation that made a speech-centre (and its correlated psycho- 

 biosis and biopsychosis) possible? The anatomical facts point to a 

 consistent variational trend of neo-pallial complexifying, from th^ 

 marmoset level to man's; and there is no special problem in the 

 fact that the apes' brains have not reached the intricacy that makes 

 language possible. 



To appreciate the psychological significance of these and similar 

 achievements, let us contrast them with others. No one who has 

 studied the terms would propose to find in the apes' behaviour any 

 evidence of Reason, as distinguished from intelligence. For Reason 

 is taken to imply conceptual, as distinguished from perceptual, 

 inference. Reasoning may be effected at an intelligent level, but 

 Reason implies experimenting with general ideas or concepts. So 

 far as we know, there is no carefully recorded instance of animal 

 behaviour that demands for its adequate description that we should 

 credit the creature with general ideas and a capacity for working or 

 playing with them. Man is often intelligent and occasionally rational; 

 animals are often reflex and instinctive, and occasionally intelligent. 



