LUXGS 



381 



thickening is that the branches of the intrapulmonary bronchus 

 form comparatively narrow canals separated by mesodermic tissue. 



3/..-<7>a/i border 



^} 



feral border 



Lateral bronchi and 

 their subdivisions 



FIG. '2&l. Thala**ochf1y* caretta. (After A. Malani.) 



Moreover, a distinction of the bronchi into portions serving merely 

 for the passage of air and into respiratory portions becomes- 



Secondary bronchi in 

 anterior part of lung 



Ventral second- 

 ary bronchi 

 with alveoli 



Swollen termina- 

 tion of main 

 bronchus 



Dorsal border 



Dorsal secondary bronchi 

 with alveoli 



FIG. 288. LUNG OF Alligator mississipiensis. 



The bronchus enters the lung some distance from the anterior end. 

 (After A. Malani ) 



gradually more marked, and thus eventually leads to the condition 

 seen in Birds and Mammals. Both ontogenetically and phylo- 



