46 THE STORY. OF <THE: BIRDS: 
tempts to pluck away), or even the iris may turn red, 
green, or golden. The inflated air sacs may be beauti- 
fully orange, and the usually dull-hued feet may grow 
pink or yellow, blue or greenish—even banded in 
some cases, like striped hose. 
But the greatest display of color is well known 
to be upon the plumage. Here the mere act of stain- 
ing runs nearly the entire spectrum, but, not content 
with this, ornamentation again dominates structure 
and provokes polish and general prismatic effects till 
pigment is merely subservient to splendor, and the 
love for distinct hues yields to the beauty of their 
blending. 
Many of the brilliant gorgets of the humming 
birds and others, viewed with the proper angle, give 
any or all the colors of the spectrum. 
Brilliancy seems always to have been progressive. 
Birds grow yearly more esthetic. There is little, if 
any, evidence that any bird has ever receded one step 
from ornamentation or dressed in duller hues after 
having once been brilliant. With only a few known 
exceptions, no young bird is more brilliant than its 
most brilliant parent, thus not indicating degenera- 
tion of color. There are some cases of one color hav- 
ing been substituted for another. Some have changed 
the style of ornamentation for a better one; some, as 
the thrushes and others, have lost spots which were 
incidentally ornamental, perhaps, but not selected or 
appreciated by its mate as such. 
It seems the more remarkable since, as we shall 
see later (Chapter X XIX), in many other respects 
