Fig. 1. (A). Dorsal view of the trachea (circled) and the lung of the ostrich Struthio camelus. The lungs are deeply entrenched into the ribs on the dorsolateral aspects (arrowhead). Filled circle, right extrapulmonary primary bronchus (EPPB). Note that the right EPPB is relatively longer, rather horizontal and relatively narrower compared with the left EPPB. Scale bar, 1 cm. (B) Close up of the dorsal aspect of the lung showing the deep costal sulci (s). Trachea, circled; filled circle, right extrapulmonary primary bronchus. Scale bar, 2 cm.