PKOTECTIVE MIJIICRY. 199 



This opens up aa interesting question, Tvhich may be referred 

 to parentheticallj", as it does not strictly bear upon the matter' 

 at hand. Dr. Seitz cnlls attention to the coincidence, but 

 does not pursue the matter farther. The question whether 

 mutilations are ever inherited has been hotly discussed ; the 

 inheritance has been affirmed and denied. A South American 

 bird, the Motmot, has the curious habit of plucking off the 

 barbs of some of the tail feathers, leaving only the tip un- 

 injured ; this produces a racket-shajjed feather, which is very 

 characteristic of the bird. It is said that the voung birds 

 have the tail feathers narrower in the middle where the barbs 

 are plucked out. It is difficult, however, to understand how 

 any alteration of a dead structure, as a feather is at the 

 extremity, could affect the living tissues and so produce in 

 course of time a modification. The same difficulty also occurs 

 in the butterfly, though it is perhaps not so great : the wing- 

 is permeated with air-channels, and by blood vessels also, 

 which may possibly send minute branches to the " roots " of 

 the scales. 



To return to the flexibility of the wings of Acrteids and 

 .Danaids : this peculiarity is less important to distasteful 

 insects than it would be to protectively-coloured insects. It 

 would be undoubtedly a asefal form of protection ; but if the 

 attacks of insect-eating ci'eatures are so frequent as to have 

 led to this modification, one is disposed to question the advan- 

 tage of the warning coloration. 



Mimicry between Protected Forms. 



The case of Leptali-s Theonoe and Itl/uinia ilerdiuu, illus- 

 trated by the woodcuts on page 104, is a typical case of 

 mimicry ; a sweet-tasting Leptalis gains jn'otection by imitat- 

 ing a disagreeably flavoured Ithomia. The mimicry is not, 



