THE WORLD OF LIVING ORGANISMS 145 



Koehler lays special emphasis on the fact that every 

 action is to be grasped as a unity, comprehensible as a whole 

 only with reference to the aim. He went on to alter and to 

 multiply the part-actions which make up the action as a whole. 

 He made the monkey use a short stick to draw a long stick 

 towards itself before it could get at the banana. And here 

 came in the limits of individual talent dependent on inherent 

 differences. To use my terminology, different monkeys had 

 at their disposal different lengths of impulse-sequences. 



The question of " intelligence " in monkeys, which Koehler 

 raises, goes far beyond the scope of biology. 



PAIN 



Pain forms one of the most powerful indications. It is an 

 indication of the subject's own body, and its chief duty is to 

 prevent self -mutilation. So it imposes a strong check which 

 shall prevent, in all circumstances, the continuation of any 

 initiated action that is hurtful to the body. 



This is especially necessary in the case of carnivorous 

 animals ; rats, for instance, will immediately devour their 

 own legs, if the sensory nerves to these have been severed. 



Now in many animals a tendency to self-mutilation is a 

 fundamental arrangement in their organisation, serving to save 

 the whole body by the sacrifice of imperilled limbs. In such 

 animals, the action of pain as a. check to the reflex would 

 merely be an inconvenience, and so we may assume that it is 

 not there. 



Moreover, in some cases where there is no tendency to 

 self -mutilation, it can be shown directly that there is no pain, 

 for even when the body is being injured there is no check 

 set up. You can put the hind end of the big brow*n dragon- 

 fly between its own jaws, and see how it proceeds to chew 

 up its own body. 



K 



