222 THEORIES OF MIMICRY 



cause of its persistence, and, by the selection of variations 

 going further in the same direction, of its improvement, 

 would have been rejected, probably with indignation, by 

 the distinguished authors of the Introduction. 



Bates's great paper dealt with the fauna of tropical 

 America, and the generalization was manifestly incomplete 

 until it had been extended to other parts of the world. 

 This confirmation was not long in coming, being supplied 

 for the tropical East by A. R. Wallace's paper published 

 in the Transactions of the Linnean Society, 1 and for 

 Africa by Roland Trimen's paper, also to be found in the 

 Transactions of the same Society. 2 



It is remarkable how completely the Linnean Society 

 has been the medium for the publication of classical 

 memoirs upon Mimicry. Up to the year 1870 it con- 

 tained them all ; while in 1858 it served as the channel 

 through which the parent theory of Natural Selection was 

 first given to the scientific world. The next great advance 

 did not take place until 1879, and was published else- 

 where. 



Bates had called attention to certain resemblances 

 which could not be interpreted under his Theory of 

 Mimicry, viz. the frequent similarity between the specially 

 defended forms themselves. Species which are them- 

 selves the models for Mimicry nevertheless mimic or at 

 least resemble other models. For such cases Bates could 

 only suggest the direct action of some unknown local force 

 or forces, and in this interpretation he was at first followed 

 by Wallace. 



In May, 1879, Fritz Muller published a paper in 

 Kosmos A which for the first time offered an explanation, 

 based on the theory of Natural Selection, of these 

 mysterious resemblances. He suggested that such like- 

 ness between dominant forms was advantageous, inasmuch 

 as it facilitated the education of their enemies, reducing 

 the amount of destruction which must be wrought during 

 the time in which young birds and other animals are 

 learning what to eat with impunity and what to reject. 



1 1866, vol. xxv, p. i. 2 1870, vol. xxvi, p. 497. 



3 Ituna and Thyridia ; a remarkable case of Mimicry in Butterflies. 



