Figure 1 of Zhang, Mol Vis 2012; 18:348-361.

Figure 1. The morphology of developing chicken scleral ossicles imaged using fluorescence stereomicroscopy. A: The development of chicken scleral ossicles at stages E10 to E21. B: The details of ossification, including the overlapping of adjacent ossicles along the dorsal quadrant of the ring. A: Scale bar: 1 mm; B: Scale bar: 0.5 mm.