Figure 3: Development of cartilage and bone structures of the forelimb in Gallus gallus embryos and fetuses, between 9 and 19 days of incubation. A and B. Histological section of phalanges (Ph) in embryos with 9 days. C. Radio (r) and ulna (U) at day 9. D-F: Forelimb at 10 days. In D, the articulation humerus, ulna and radius. Notice in E the presence of feathers germ (FG). In F: note the intense blood flow (arrow) in the region of the humerus articular surface (AS). AC: Articular Capsule. G: wing development in embryos with 12 days. H: Medial view of the wing joint of 19 days embryos: a. phalanges, b. carpus. c. radius and ulna.