^68 Mr. A. H. Thayer on 



"oi" the Peacock family. An artist can see that whereas 

 unshiny monochrome reveals its wearer to the utmost, 

 iridescence, on the other hand, destroys visibility of surface, 

 by substituting for a normal light-and-shade gradation, a 

 totally new succession of colour and light notes, and above all 

 one that changes its character with every movement of the 

 bird, and every change of the beholder's standpoint. Add 

 to this in the Peacock's case, for instance, his habitual 

 resort to dense cover, and his gorgeous blue and green 

 gleams, through its interstices, present merely the aspect 

 of foliage-colours and hints of flower- masses. I feel sure 

 that Peacock hunters will testify that this bird is hard to 

 see when lying close. 



Let us imagine an animal stalking; this bird. He will 

 look u-lwlly for mot/ion: — (such at least is the habit of all 

 predatory creatures I know). Now it is the peculiar 

 property of sheen, that it will stand stdll while the thing it 

 is on moves. This means that a Peacock can move his 

 brilliant neck, while its sheen stands still, — just as the 

 gleam on the telegraph wires keeps pace with the railway 

 train as one sees it from the window. And since this 

 gleam of the bird's neck must be the most visible thing, 

 the possibility of the neck's gliding along hehind it, while 

 it stands still, must often save the Peacock ; (for the balance 

 between the evolved sldll of tlte Jmntcr and the evolved skill 

 of the hunted must always be close, and smallest advantages 

 must often tip the scale). While the fore-part of the bird 

 is beginning to move, unnoticed, his conspicuous tail, a 

 yard behind his vital parts, catches the tiger's eye, in its 

 earliest motion, and the tiger, seeing no other part so 

 distinctly, springs at these long feathers, whose design is 

 arranged for conspicuonsness in motion. 



These gorgeous birds will prove to be additionally con- 

 cealed, not revealed, by their costumes. It is worth men- 

 tioning here, in connection with the Warning-Colour 

 theory, that Avhile Peacocks and Pheasants are iridescent 

 2Jlumciged birds, and would be called conspicuous in the 

 highest degree, they are not iin-palatahh ; — a fact that goes 

 to strengthen my argument. 



The next thing to be pointed out is that the general 

 tendency of birds to wear longitudinal markings forward, 

 and transverse ones aft, is an important factor of protec- 

 tion, especially in the case of the Pheasants and Peacocks, 

 among whom this arrangement is very highly develoj)ed. 



