Figure 5.

Cross‐sections of the internasal and nasal‐premaxilla sutures of emus stained with toluidine‐blue. (A) Internasal and nasal‐premaxilla sutures of Emu 3. The bone stains deep blue and the cartilage of the nasal capsules is purple. (B) Internasal and nasal‐premaxilla sutures of Emu 6. (C) Close‐up of the middle red box in (A). The suture is composed of a cambial layer (double white arrows) and a middle layer (white asterisk) formed of loose irregular connective tissues and some vessels (black arrows). (D) Close‐up of the right box in (A) showing an actively growing bone and the formation of vascular canals. (E) Close‐up of the left red box in (A), showing chondroid bone (up) and hyaline cartilage (down, in purple). Cells of chondroid bone are cartilage‐like (round) but are embedded in a bone matrix. Hyal. C, hyaline cartilage; Na, nasal; Na. caps. c., Nasal capsule cartilage; Pm, premaxilla.