22 4 THE WONDER OF LIFE 



own particular kind of prey, which she knows instinctively ; 

 in most cases she handles her prey in a quite distinctive 

 way ; in most cases she has a particular routine when she 

 arrives at her nest. The behaviour is complex, adaptive, 

 specific and constant. There is hereditary awareness of 

 certain things (a cognitive disposition), and there is Unked 

 to that a hereditary impulsion to a certain routine (a cona- 

 tive disposition). As Dr. McDougall puts it : — 



' The structure of the mind of such an animal must be 

 conceived as consisting of a limited number of innate cog- 

 nitive dispositions, each hnked with a conative disposition ; 

 and the maintenance of the single cycle of activities, which 

 compose the life history of the adult creature, depends 

 on the fact that the exercise of each conative disposition 

 produces a situation which excites another cognitive dis- 

 position, which in turn sets to work another conative 

 disposition, and so on, until the cycle is completed '. 



Professor Lloyd Morgan relates his instructive experience 

 with a young moorhen which he had hatched in an incu- 

 bator. It swam well, but it would not dive. One day, 

 however, when it was swimming in a pool it was suddenly 

 frightened by a boisterous puppy. ' In a moment the 

 moorhen dived, disappeared from view, and soon partially 

 reappeared, his head just peeping above the water beneath 

 the overhanging bank '. Suddenly, and without warning, 

 it had exhibited a characteristic piece of behaviour, and 

 its dive was absolutely true to type. The diving perform- 

 ance was obviously something novel and specific ; it did 

 not grow out of the swimming on the surface. 



The method of seK-dehvery practised by the unhatched 

 chick within the egg used to be regarded as a sort of appren- 



