568 Mr. A. H. Thayer on 
of 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 wholly for motion :—(such at least is the habit of all 
predatory creatures I know). Now it is the peculiar 
property of sheen, that it will stand sti// 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 behind it, while 
it stands still, must often save the Peacock ; (for the balance 
between the evolved skill of the hunter 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 conspicwousness 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 while Peacocks and Pheasants are iridescent 
plumaged birds, and would be called conspicuous in the 
highest degree, they are not unpalatable ;—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 developed. 
