64 Heredity and Instinct 



instinct the muscular coordination is brought into play 

 directly by a sense stimulation ; while in intelligence it is 

 brought into play indirectly, i.e., through association of 

 brain processes, with selection of fortunate combinations. 

 Now this difference in the central brain connections is, I 

 submit, not at all a great one, relatively speaking, and 

 it might well be due to spontaneous variations. The 

 point of view which holds that great co-adaptations of the 

 muscles have to be acquired all at once by the creature is 

 quite mistaken. 



§ 3. Instinct ajid Lamarckism : ^Selective Valne' 



The same class of considerations refutes the argument 

 from * selective value.' ^ This argument holds that the 

 instinct could not have arisen by variations alone, with 

 natural selection, since partial coordinations tending in the 

 direction of the instinct would not have been useful ; so 

 the creatures with such partial coordinations merely would 

 have been killed off, and the instinct could never have 

 reached maturity ; only variations which are of sufficient 

 value or utility to be ' selective ' would be kept alive and 

 perfected. 



But we see that the intelligence which is appealed to, to 

 take the place of instinct and to give rise to it, uses just 

 these partial variations which tend in the direction of the 

 instinct ; so the intelligence snpplemeiits such partial coor- 

 dinations, makes them functional, and so keeps the creature 

 alive. This prevents the 'incidence of natural selection,' 

 to use a phrase of Professor Lloyd Morgan's. So the sup- 

 position that intelligence is operative turns out to be just 



^ In my opinion * selective value ' is equivalent simply to * utility ' : any 

 amount of utility is * selective.' 



