ClipArt ETC
"Fig. - 20 - Two barbs, a, a, of a vane, bearing anterior, b, b, and posterior, c, barbules; enlarged; after Nitzsch." Elliot Coues, 1884

Structure of a Feather

"Fig. - 20 - Two barbs, a, a, of a vane, bearing anterior, b, b, and posterior, c, barbules; enlarged;…