Objections to the Theory 



therefore, insufficient to prove the utility of the 

 perfected resemblance. We may readily grant 

 this and yet maintain that the origin of the 

 resemblance cannot be due to the action of 

 natural selection. 



The Drongo-cuckoo (Surniculus lugubris] dis- 

 plays so great a likeness to the King Crow 

 (Dicrurus ater) that it is frequently held up by 

 Neo-Darwinians as an excellent example of 

 mimicry among birds. But D. Dewar writes, 

 on page 204 of Birds of the Plains : "I do not 

 pretend to know the colour of the last common 

 ancestor of all the cuckoos, but I do not believe 

 that the colour was black. What then caused 

 Surniculus lugubris to become black and assume 

 a king-crow-like tail? 



" A black feather or two, even if coupled with 

 some lengthening of the tail, would in no way 

 assist the cuckoo in placing its egg in the 

 drongo's nest. Suppose an ass were to borrow 

 the caudal appendage of the king of the forest, 

 pin it on behind him, and then advance among 

 his fellows with loud brays, would any donkey of 

 average intelligence be misled by the feeble 

 attempt at disguise? I think not. Much less 

 would a king- crow be deceived by a few black 

 feathers in the plumage of a cuckoo. I do not 

 believe that natural selection has any direct con- 

 nection with the nigritude of the drongo-cuckoo." 



Darwin was fully alive to this difficulty when 

 233 



