182 PKO'l'BCTIVE RESEMBLANCE IN ANIMALS. 



imitate various memliers of tlie Hymenopterous order ; 

 but we liave now to notice a case where a motli imitates a 

 bird so completely as to deceive even the best observers 

 when the two creatures are on the wing tocjether. The 

 motiis in which this kind of mimicry occurs take their 

 name of humming-bird hawk-moths from this very cir- 

 cumstance, and are represented by a species not very 

 uncommon in some parts of our own country. So close 

 is the resemblance between these moths and humming- 

 birds that Mr. Bates tells us that, when on the Amazons, 

 he has actually shot specimens of the former in mistake 

 for the latter ; and the natives of these regions are firmly 

 convinced that both are of the same species. The ex- 

 tended ]n-ohoscis of the moth does duty for the slender 

 beak of the liird, while the end of the body of the former 

 is exjjanded into a kind of brush which imitates the tail 

 of the bird. Humming-birds are, of course, not seized as 

 l)reY by insectivorous birds, and hence the moths escape 

 their natural enemies from their resemblance to the 

 humming-birds. In our own country, where there are 

 no humming-birds, it is somewhat difficult to see what 

 advantage itB bird-like form is to the humming-liird hawk- 

 moth, and possibly its comparative rarity may be due to 

 the al)sence of the liirds it mimicks. 



We come now to those very remarkable cases of 

 mimicry, as exemplified among the butterflies, where one 

 species mimicks one or even more members of the same 

 order, owing to the immunity of the latter from the 

 attacks of liirds on account of their unpalatable taste. 

 That the mimicked butterflies are protected by their un- 

 pleasant taste has been amply proved by their being 

 ofliered o^'er and over again to liirds, by whom they are as 

 invariably rejected. Their immunity from attaclv is 

 further proved by their slow flight, and by the bright 

 colouring of the under sides of their wings, so that they 

 have no means of concealing themselves. Most of these 

 mimicked butterflies are found in tropical and subtropical 

 regions, and belong to the great families known as 

 Daniidce and Helicoiiiidie. In America these butterflies 

 are usually mimicked by various species of the family of 



