36 THE DESCENT OF MAN. [Part I. 



that apes have an instinctive dread of serpents, and prob- 

 ably of other dangerous animals. 



The fewness and the comparative simplicity of the in- 

 stincts in the higher animals are remarkable in contrast with 

 those of the lower animals. Cuvier maintained that instinct 

 and intelligence stand in an inverse ratio to each other ; and 

 some have thought that the intellectual faculties of the 

 higher animals have been gradually developed from their 

 instincts. But Pouchet, in an interesting essay, 2 has shown 

 that no such inverse ratio really exists. Those insects 

 which possess the most wonderful instincts are certainly 

 the most intelligent. In the vertebrate series, the least 

 intelligent members, namely fishes and amphibians, do not 

 possess complex instincts ; and among mammals the ani- 

 mal most remarkable for its instincts, namely the beaver, 

 is highly intelligent, as will be admitted by every one 

 who has read Mr. Morgan's excellent account of this animal. 9 



Although the first dawnings of intelligence, according 

 to Mr. Herbert Spencer, 4 have been developed through the 

 multiplication and coordination of reflex actions, and al- 

 though many of the simpler instincts graduate into actions 

 of this kind, and can hardly be distinguished from them, 

 as in the case of young animals sucking, yet the more 

 complex instincts seem to have originated independently 

 of intelligence. I am, however, far from wishing to deny 

 that instinctive actions may lose their fixed and untaught 

 character, and be replaced by others performed by the aid 

 of the free will. On the other hand, some intelligent ac- 

 tions — as when birds on oceanic islands first learn to avoid 

 man — after being performed during many generations, be- 

 come converted into instincts, and are inherited. They 



2 ' L'Instinct chez les Insectes.' ' Revue d'es Deux Mondes,' Feb. 

 1870, p. 690. 



8 The American Beaver and his Works,' 1868. 



« 'The Principles of Psychology,' 2d edit. 1870, pp. 418-443. 



