These objects contain "sphere-type" and "channel-type" nanostructures responsible for their optical properties. Detecting UV from these objects that have a UV reflectance as high as 10% is one of the major functions of a class of cones that contains T-type droplet oil. These objects contain melanosomes (-5[1])in "hollow platelet" and "hollow rod" shapes. After studying how the color of these objects varies with climate, Constantin Gloger proposed his namesake rule. Both insect scales and these objects contain gyroid-shaped (*) photonic crystals. Robert (-5[1])Hooke is generally credited with discovering structural coloration after submerging one of these iridescent objects in water to wash away pigment, and finding their color remained. James Gregory discovered diffraction gratings by passing sunlight through the barbs and barbules of these objects. For 10 points, name these colorful objects that compose plumage. (10[1]) (10[1])■END■