260 COMPARATIVE MORPHOLOGY OF VERTEBRATES. 
Fic. 269. Fic. 270. 
Fic. 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; , 
parabronchi. 
Fic. 270.—A, lung pipes of bird from a corrosion preparation; B, section of lung pipe 
with radiating infundibula, after Schulze. . 
Fic, 271.—Diagram of the relations of the chief air sacs in a bird, lung tissue shaded. 
a, axillary sac; cb, abdominal sac; ai, anterior intermediate sac; 6, bronchus; pb, pre- 
bronchial sac; pi, posterior intermediate; sb, subbronchial sac; ¢, trachea. 
