A STUDY OF MIMICRY 15 



Here both mocked and mockers were protected by 

 nauseousness, and it was by no means clear to him 

 how any advantage, the fmidameiital cause of 

 variation of this kind, was to be gained by such 

 imitation. The resemblance was so close that, 

 according to his own words, " species belonging 

 to distinct genera have been confounded, owing 

 to their being almost identical in colors and mark- 

 ings ; in fact, many of them can scarcely be dis- 

 tinguished except by their generic characters." 

 Bates himself was inclined to look upon these, 

 not as cases of parastatic mimicry, but as due " to 

 the similar adaptation of all to the same local, 

 probably inorganic conditions." 



But this vague explanation has not been satis- 

 factory to others, and Wallace and Meldola, and 

 particularly Fritz Miiller, have followed the mat- 

 ter, and shown that, if the mimicked species 

 possesses the slightest advantage in the mere 

 point of numbers over the mimicking, this advan- 

 tage is sufficient to produce the mimicry con- 

 cerned. It is highly probable, from the experi- 

 ments of Fritz Miiller and the observations of 

 Belt, that the Heliconoid butterflies are simply 

 distasteful, not poisonous, to insectivorous animals. 

 Miiller has even figured a considerable number of 



