MENTAL POWERS. 65 



and man has no such knowledge: but as our domestic animals, 

 when taken to foreign lands, and when first turned out in the 

 spring, often eat poisonous herbs, which they afterwards avoid, 

 we cannot feel sure that the apes do not learn from their own 

 experience or from that of their parents what fruits to select. 

 It is, however, certain, ^ as we shall presently see, that apes have 

 an instinctive dread of serpents, and probably of other dangerous 

 animals. 



The fewness and the comparative simplicity of the instincts 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,'' 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 amongst mammals the animal 

 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 work.'' 



Although the first dawnings of intelligence, according to Mr. 

 Herbert Spencer,* have been developed through the multiplica- 

 tion and co-ordination of reflex actions, and although many of 

 the simpler instincts graduate into reflex actions, 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, very 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 actions, 

 after being performed during several generations, become con- 

 verted into instincts and are inherited, as when birds on oceanic 

 islands learn to avoid man. These actions may then be said 

 to be degraded in character, for they are no longer performed 

 through reason or from experience. But the greater number of 

 the more complex instincts appear to have been gained in a 

 wholly different manner, through the natural selection of varia- 

 tions of simpler instinctive actions. Such variations appear to 

 arise from the same unknown causes acting on the cerebral 

 organization, which induce slight variations or individual dif- 



2 'L'Instinct chez les Insectes.' 'Revue des Deux Mondes,' Feb. 1870, 

 p. 690. 



3 'The American Beaver and his Works,' 1868. 



■* 'The Principles of Psychology,* 2nd edit. 1870, pp. 418-443. 

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