BIKD-ALTEUISM 73 



after the usual help to start them in life the parents 

 found leisure to inspect the empty nest. They evidently 

 thought that with a little necessary repairs it might be 

 utilized for the rearing of another brood. They seemed 

 to remember, however, the sad loss of one of their former 

 family, and concluded that the nest was too shallow for 

 safety. They accordingly set about the work of raising 

 the sides, and when the repairs were completed, the nest 

 had the curious appearance of a ring of bright-coloured 

 material, about three-quarters of an inch deep, all round. 

 In this enlarged nest they successfully reared a brood of 

 four. 



EICHAED G. Eoss. 



September 9, 1900. 



NOTE. The action of the thrushes demonstrates how 

 intelligence co-operates with instinct. A special circum- 

 stance asked and received the response of individual 

 experiment, and this response penetrated the instinctive 

 faculty of nest-building. The latter is a congenital in- 

 heritance of the species as a whole, quite different from 

 an acquired habit and depending on individual conscious- 

 ness and experiment only in so far as a " perceptual pur- 

 posefulness " (viz., intelligence) can perfect the work- 

 ing of an " instinctive purposiveness." In an emergency, 

 instinct, being no longer of service, is replaced by a full 

 intelligence or the individual of the species takes the 

 consquences. Eoutine, of course, is a sine qua non of 

 all life ; we should not get far if we had to work out 

 the physiological problem of putting one leg before 

 another every time wo moved about. But nature is 

 properly fearful of too deep a rut, since stagnation is the 

 enemy of change and reform. So life for the higher 

 animals is never a jog-trot ; its elements contain enough 

 of the incalculable and indeterminate to be ever examining 

 the living creature in fresh problems, to sharpen its 

 faculties, to prod it into initiative, to awaken new ideas, 



