The Black-and- Yellow Grosbeak 



case of organisms which occupy the same areas 

 of the earth. Thus it is quite possible that 

 many so-called cases of mimicry are nothing of 

 the kind. 



The mere fact that one of the organisms in 

 question may profit by the likeness is not suffi- 

 cient to demonstrate that natural selection is 

 responsible for the resemblance. 



In this connection we must bear in mind that, 

 according to the orthodox Darwinian theory, 

 the resemblance must have come about gradu- 

 ally, and in its beginnings it cannot have profited 

 the mimic as a resemblance. 



So plastic are organisms, and so great is the 

 number of living things in the earth, that it is 

 not surprising that very similar forms should 

 sometimes arise independently and in different 

 parts of the globe. Several instances of this 

 fortuitous resemblance are cited in Beddard's 

 Animal Colouration ; others are cited in The 

 Making of Species by Finn, and myself. 



Perhaps the most striking case is that of 

 a cuckoo found in New Zealand, known as 

 Eudynamis taitensis. This is a near relative of 

 the Indian koel, which bears remarkable resem- 

 blance to an American hawk {Accipiter cooperi). 



Writing of this cuckoo, Sir Walter Buller says : 



171 



