COLOURS OF ANIMALS 



erastus) is coloured so exactly like these that it was at first 

 described as a species of Pieris. None of these four groups 

 are known to be in any way specially protected, so that the 

 resemblance cannot be due to protective mimicry. 



In South America we have far more striking cases, for in 

 the three subfamilies Danainse, Acrseinse, and Heliconiinae, all 

 of which are specially protected, we find identical tints and 

 patterns reproduced, often in the greatest detail, each peculiar 

 type of coloration being characteristic of distinct geographical 

 subdivisions of the continent. Nine very distinct genera are 

 implicated in these parallel changes Lycorea, Ceratinia, 

 Mechanitis, Ithomia, Melinsea, Tithorea, Acrsea, Heliconius, 

 and Eueides, groups of three or four (or even five) of them 

 appearing together in the same livery in one district, while 

 in an adjoining district most or all of them undergo a simul- 

 taneous change of coloration or of marking. Thus in the 

 genera Ithomia, Mechanitis, and Heliconius, we have species 

 with yellow apical spots in Guiana, all represented by allied 

 species with white apical spots in South Brazil. In Mechan- 

 itis, Melinaea, and Heliconius, and sometimes in Tithorea, the 

 species of the Southern Andes (Bolivia and Peru) are char- 

 acterised by an orange and black livery, while those of the 

 Northern Andes (New Granada) are almost always orange- 

 yellow and black. Other changes of a like nature, which it 

 would be tedious to enumerate, but which are very striking 

 when specimens are examined, occur in species of the same 

 groups inhabiting these same localities, as well as Central 

 America and the Antilles. The resemblance thus produced 

 between widely different insects is sometimes general, but 

 often so close and minute that only a critical examination of 

 structure can detect the difference between them. Yet all 

 are alike protected by the nauseous secretion which renders 

 them unpalatable to birds. 1 



In another series of genera (Catagramma, Callithea, and 

 Agrias), all belonging to the Nymphalidae, we have the most 

 vivid blue ground, with broad bands of orange, crimson, or a 

 different tint of blue or purple, exactly reproduced in corre- 

 sponding, yet unrelated species, occurring in the same locality ; 



1 The above cases have now been satisfactorily explained as a modified 

 form of mimicry. See Darwinism, pp. 249-257. 



