260 



COMPARATIVE MORPHOLOGY OF VERTEBRATES. 



PL 



FIG. 269. FIG. 270. 



FIG. 269. Diagram of structure of bird's lung, a, connexions of bronchi with air 

 sacs; b, bronchus; e, entobronchi; ec, ectobronchi; i, infundibula; m, mesobronchus; p, 

 parabronchi. 



FlG. 270. A, lung pipes of bird from a corrosion preparation; B, section of lung pipe 

 with radiating infundibula, after Schulze. 



FIG. 271. Diagram of the relations of the chief air sacs in a bird, lung tissue shaded. 

 a, axillary sac; ab, abdominal sac; ai, anterior intermediate sac; b, bronchus; pb, pre- 

 bronchial sac; pi, posterior intermediate; sb, subbronchial sac; t, trachea. 



