From a central feather shaft extends a series of slender barbs, each sprouting smaller barbules, like branches from a bough, lined with tiny hooks. When these grasp on to the hooklets of ...

(C and D) The hooklets from one barb hook the adjacent barbs and fasten the vane. (E ) Stereoscopic structure of a feather obtained via 3D reconstruction with a micro X-ray microscope. The ...