BEDROCK 



Several attempts have been made to explain the resemblance of 

 Mimic to Model, but of these it is only necessary to mention four. 



(1) Almost exactly half a century ago H. W. Bates, in his cele- 

 brated hypothesis, suggested that the abundant Models were specially 

 protected by an unpleasant taste or in other ways, and that the 

 palatable defenceless Mimics were mistaken for them, not only on 

 account of their deceptive likeness, but also because they were so 

 rare as to be lost in the swarms of an excessively common species. 

 This hypothesis has been so completely popularised in text-books, 

 articles and lectures, that, until recently, little attention has been 

 paid to any other. 



(2) Another great naturalist, Fritz Miiller, also drawing his experi- 

 ence from the South American tropics, could only accept Bates' 

 interpretation for a very few of the Mimics with which he was 

 acquainted. The majority of these were abundant flourishing 

 species belonging to groups which were evidently themselves specially 

 protected and mimicked by species of other groups. Bates, too, 

 knew of these highly successful Mimics, and recognising that they 

 could not be explained by his hypothesis, believed that they were 

 due to climate or some other influence connected with locality. 

 Fritz Miiller puzzled over these cases for many years and at first 

 thought of an explanation based on Sexual Selection. It occurred 

 to him as possible that the choice of mates might be influenced by 

 the sight of the patterns of other species ; and Darwin, to whom he 

 gave a brief account of these views, was by no means disposed to 

 regard them as extravagant or impossible. The real difficulty lies 

 in the fact that selection is exercised by females rather than by males, 

 while Mimicry, when restricted to a single sex, is, with hardly an 

 exception, found in the female. There is, in fact, far more to be 

 said in favour of the opposed hypothesis, that Sexual Selection 

 accounts for the want of Mimicry in the males of so many mimetic 

 females. 



Finally, sixteen years after the publication of Bates' hypothesis, 

 the interpretation of " Miillerian Mimicry " flashed across Fritz 

 Miiller's mind. His first brief sketch of the hypothesis, published 

 in Cams' Zoologischer Anzeiger for 1878, has almost entirely 

 escaped notice, eclipsed by the more complete account written for 

 Kosmos (May, 1879), and at once translated by R. Meldola and 



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