them and giving them a moment's grace for taking flight or crawling out of 

 reach. But their marvelous headgear masks their menacing solid forms. 

 Irradiated, as it often is, by sunlight, it matches the bright, gaudy back- 

 ground of flowers, leaves and sky, piercing and obliterating the interposed 

 bird-bodies. As, from moment to moment, the bright real scene beyond 

 flashes and twinkles and changes, so the mock scene on the hummingbird's 

 front sparkles and shifts with his every slightest movement, and every flicker 

 of the light that vivifies it.* 



It is needless to discuss here the meaning of hummingbirds' many re- 

 markable appendages, inasmuch as the high obliterative value of such de- 

 velopments in general has already been explained. 



Male and female hummingbirds are usually unlike in plumage, and their 

 differences correspond to those of most other forest birds. Furthermore, they 

 are in close and evident accord with the differences in the habits of the sexes. 

 The female sits on her neat, moss-trimmed nest, in a shady place, while her 

 mate is buzzing around among the flowers and sunbeams. The bodies, even 

 of the males, are usually equipped with obliterative shading, and the females 

 almost always have it in full development. They are dim in color, relatively to 

 their mates, being mainly soft (but often metallic) green, brown, or gray, 

 and rarely having any fully developed gemlike spots or plumes, — all of which 



* A probable minor function of this flashing headgear, under the very same conditions, is the 

 illumination, by reflected light, of the calyxes of flowers, and the shaded sides of leaves, which the 

 hovering hummers probe and search. They carry, as it were, little colored lanterns on their heads, 

 whose disk of blue or green or red or purple light can be thrown deep into a tubular flower, or moved 

 up and down and back and forth across a dusky leaf. When any of the very bright ones among these 

 gaudy little 'reflectors' are played on by bright sunlight, and headed more or less directly sunward, 

 they cast a really illuminating glow, which can scarcely fail to be of service to the hummers in their 

 insect-hunting. Again, it is likely that the flaming head-dresses of these little birds— as also the erec- 

 tile crests of flycatchers — sometimes act as "war paint." When a male hummer leaves his hovering 

 and perching amidst flowers, where his colors are potently obliterative, and launches forth into free 

 air, often above the tree-tops, in violent pursuit of another bird, his fiery-flashing brilliance may 

 well cooperate with the arrowy vehemence of his attack in frightening the object of his anger. Far 

 oftener, however, it must tend rather to dazzle and stupefy the persecuted bird, and, by its incessantly 

 varied gleaming, to bewilder him as to the exact position of the chaser. 



I05 



