52 THE THEORY OF NATURAL SELECTION 



Resemblances can only be properly explained as 

 representing cases of mimicry when both the species 

 concerned the mimic and the mimicked inhabit the 

 same locality.; but plenty of cases of matching between 

 the colour patterns of insects which live in quite 

 different parts of the world could also be pointed out. 

 Let us take a concrete example. Everyone is familiar 

 with the flower-frequenting flies (Syrphidce) which are to 

 be seen hovering about plants in sunny weather. These 

 insects closely mimic the appearance of various small 

 bees and wasps, the habits of which are similar. Here, 

 then, is surely a case where the deceptive resemblance 

 to an animal well armed in its sting must cause pro- 

 spective enemies to let these flies alone. In Southern 

 Japan, as Dr. Andreae pointed out to me, flies of this 

 kind are surprisingly numerous, and their resemblance 

 to bees particularly noticeable. So abundant are they 

 that, from the point of view of the flowers which they 

 visit, these flies doubtless provide an efficient substitute 

 for the bees of other countries, which are here con- 

 spicuous by their absence. But if real stinging insects 

 are wanting, or even very scarce, the supposed enemies 

 of the flies can have no experience of the ill-effects 

 produced by catching them. How, then, can these 

 flies benefit from their resemblance to bees ? 



This kind of thing must make us somewhat sus- 

 picious of supposed cases of mimicry even between 

 species possessing the same range. 



When the ideas of mimicry and protective resem- 

 blance are carried into the vegetable kingdom, as they 

 have been by some writers, absurdities are soon found 



