346 OUTLINES OF E VOLUTION ABY BIOLOGY 



When an unquestionably harmless species mimics the warning 

 colours of an undoubtedly noxious one, the case is sometimes 

 spoken of as one of " Batesian " mimicry, after the distinguished 

 naturalist, H. W. Bates, who added so much to our knowledge of 

 the subject. In the case of a synaposematic group, or mimicry 

 ring, however, it is often impossible to say whether any particular 

 species is edible or not, and it may very well be that in some 

 cases all are more or less inedible, though undoubtedly some, 

 which are presumably the less objectionable forms, mimic others, 

 which are presumably the more objectionable. This kind of 

 mimicry, resulting in the development of a warning colour 

 common to a number of inedible species, is sometimes distin- 

 guished as "Miillerian" mimicry, after the naturalist Fritz 

 Miiller, who first suggested the correct interpretation of the 

 phenomenon. 



Perhaps the most remarkable case of mimicry known 

 amongst butterflies is that of certain species of Papilio found in 

 Africa and Madagascar, which have formed the subject of 

 exhaustive study by Trimen, Poulton and others. In Madagascar 

 occurs Papilio meriones, a non-mimetic species in which the 

 male and female (Fig. 177, A) closely resemble one another and 

 both possess the " tail " on the hind wing which is such a charac- 

 teristic feature of the genus. We may take it, then, that this is a 

 primitive form. On the continent of Africa is found the wide- 

 spread Papilio dardanus, with several subspecies. In these sub- 

 species the male (Fig. 177, BI) retains the ancestral form, but in 

 most of them the female is mimetic ; it has lost the Papilio tail 

 and closely mimics, both in shape and colour markings, some 

 one or another of various species of butterflies belonging to 

 different families which occur in the same region. Nor is this 

 all, for the female is likewise polymorphic, and different 

 individuals of the same subspecies resemble widely different 

 models. Thus the subspecies merope is known to have three 

 forms of female, a hippocoon form (Fig. 177, B 2 ) which mimics 

 the danaine butterfly Amauris niavius (Fig. 177, C), a trophonius 

 form (Fig. 177, B 3 ) which mimics another danaine, Limnas 

 chrysippus (Fig. 177, D), and a planemoides form which mimics 

 the acraeine, Planema poggei. Our illustrations, which are 

 reproduced from Mr. Trimen's original memoir, give a good 

 idea of the form and pattern of some of these insects, but they 

 lack the beautiful colouring of the original figures, which is 



