NATURAL SELECTION AS APPLIED TO BIRDS 329 



Now in the Cuckoo the male only is black, the female being 

 brown. But this is of no consequence, for when these repre- 

 hensible parents desire to foist their offspring on their dupes, 

 the male takes upon himself the task of drawing off the owners 

 of the chosen nursery. The sequel, however, is curious. As 

 a rule, when the male differs from the female in plumage among 

 birds, the young resemble the female. Did this rule obtain 

 with the young of the Myna they would speedily be destroyed 

 by the jealous foster-parents. But it does not obtain, the 

 young instead resemble the male parent, and don a black 

 dress, whereby they resemble the young Mynas, and so escape 

 detection ! 



But besides cases of mimicry which appear to have been 

 evolved for the purpose of rendering parasitism possible, there 

 are many others which have had a more worthy object — if any 

 such could be regarded as instances of conscious mimicry, which 

 of course is not the case. There are cases where the subjects 

 are weak and defenceless, but' where, by assuming the guise 

 of a pugnacious species they have escaped persecution, and 

 lessened the severity of the struggle for existence. 



The Orioles- and Friar-birds of the Malay Archipelago 

 furnish the best-known examples of this kind of mimicry. The 

 Friar-birds are large honey-suckers, belonging to the Genus 

 Tropidorhynchus. Dull in plumage, but armed with sharp 

 curved beaks and strong claws, they are well able to take care 

 of themselves, and would seem to be more or less dreaded by 

 their neighbours, being noisy birds which go about in small 

 flocks, and successfully drive away Crows and Hawks which 

 venture too near their haunts. The Orioles, on the other 

 hand, come of a very brightly coloured stock. But where they 

 live in the same area with the Friar-birds they have assumed 

 a similar dull coloration. " In each of the great Islands of the 

 Austro-Malayan region," says Alfred Russel Wallace, "there 

 is a distinct species of Tropidorhynchus {Philemon), and there is 

 always along with it an Oriole that exactly mimics it. All the 

 Tropidorhynchi have a patch of bare skin around the eyes, and 

 a ruff of curious pale recurved. feathers on the nape, whence their 

 name of Friar-birds, the ruff being supposed to represent the 

 cowl of a friar. These peculiarities are represented in the 

 Orioles by patches of feathers of corresponding colours : while 



