The morphological and structural development of the syrinx was studied with a light microscope in 100 female and male Japanese quails from 1 to 60 days old and adults. The quails had a tracheobronchial syrinx since it was based on both tracheal and bronchial elements. Two tracheal syringeal cartilages were attached at both ends to the pessulus in the tympanum. In this species the tympanum had a slightly increased diameter. The pessulus was a wedge-shaped cartilage, its blade lying dorsoventrally so that it divided the airway vertically.