22 ANTS AND SOME OTHER INSECTS. 



There are no abstract concepts corresponding to the signs. We 

 are here concerned only with hereditary, instinctively automatic 

 signs. The same is true of their comprehension (pushing with the 

 head, rushing at one another with wide-open mandibles, titillation 

 with the antennae, stridulatory movement of the abdomen, etc.). 

 Moreover, imitation plays a great role. Ants, bees, etc., imitate 

 and follow their companions. Hence it is decidedly erroneous (and 

 in this matter Wasmann, Von Buttel, and myself are of but one 

 opinion) to inject human thought-conception and human ratiocina- 

 tion into this instinct-language, as has been done to some extent, 

 at least, even by Pierre Huber, not to mention others. It is even 

 very doubtful whether a so-called general sensory idea (i. e., a gen- 

 eral idea of an object, like the idea "ant," "enemy," "nest," 

 "pupa") can arise in the emmet brain. This is hardly capable of 

 demonstration. Undoubtedly perception and association can be 

 carried on in a very simple way, after the manner of insects, with- 

 out ever rising to such complex results. At any rate proofs of such 

 an assumption are lacking. But what exists is surely in itself suffi- 

 ciently interesting and important. It gives us at least an insight 

 into the brain-life of these animals. 



Better than any generalisations, a good example will show 

 what I mean. 



Plateau had maintained that when Dahlia blossoms are covered 

 with green leaves, bees nevertheless return to them at once. At 

 first he concealed his Dahlias incompletely (i. e., only their ray- 

 florets), afterwards completely, but still in an unsatisfactory man- 

 ner, and inferred from the results that bees are attracted by odor 

 and not by sight. 



a. In a Dahlia bed visited by many bees and comprising about 

 forty-three floral heads of different colors, I covered first seventeen 

 and then eight at 2.15 P. M., September loth, with grape-leaves 

 bent around them and fastened with pins. 



b. Of four I covered only the yellow disc ; 



c. Of one, on the other hand, I covered only the outer ray- 

 florets, leaving the disc visible. 



