76 Chapter II. 



adopting strangers as aiLviliaries. Of course, they are 

 far from having an inteUigent knowledge of this pur- 

 pose. It suffices that, on account of the actual need of 

 workers, the instinctive impulse of the ants to bring up 

 fresh workers is aroused with greater intensity and, 

 for this reason, extends to other Formica cocoons. 

 And this is the only explanation admissible, for we 

 have proved above, that with F. san guinea slave- 

 holding is not due to experience or instruction, but to 

 hereditary instincts. 



Is there anything in the social life of higher 

 animals, which can rival this strange phenomenon? 

 We know of nothing. If there had been, then Darwin, 

 Ziegler and other evolutionists would not have failed 

 to turn it to account, and to appeal to it as convincing 

 proof of the ''quasi-human intelligence" of higher 

 animals ; for, if an association of animals perceives 

 the necessity of increasing its strength by adopting 

 auxiliary forces, and under the influence of this per- 

 ception actually adopts them, then this action proceeds 

 from a motive originating in sensitive experience, and 

 is therefore intelligent^ at least according to modern 

 animal psychology. Nevertheless, ants are said to be 

 "instinct automatons," but higher animals are not! 

 And this again shows, how utterly untenable, on the 

 one hand, is the modern notion of intelligence, and, 

 on the other, how foolish the attempt to place the 

 "intelligence" of the higher animals on a far higher 

 level than that of ants. 



Bethe,^ indeed, has of late made an attempt to 

 explain, in a very simple manner, the proportion 



*) "Duerfen wir den Ameisen und Bienen psychische Qualitaeten 

 zuschreiben?" p. 69. 



