132 



STUDENTS HISTOLOGY 



bottom and top, and show no epithelial lining excepting at 

 inner edge of periphery. 



3. The alveoli, C, C, divided so as to show a cup- shaped bot- 

 tom or top. (The minute granules are the nuclei of the lining 

 cells.) 



4. The alveoli, D, D, so cut as to leave most of bottom or 

 top, showing an opening in the center where the sac has been 

 sliced off. 



FIG. 89. SECTION OF LUNG OF PIG. STAINED WITH H^EMATOXYLIN AND 



EOSIN (X60). 



A, A. Infundibula in T. S. 



B, B, B. Alveoli; so sectioned as to show the outline only. 



C, C, C. Alveoli; so sectioned as to present cup-shaped cavities. 



D, D, D. Alveoli; so sectioned as to divide the top (or bottom). 



E, E. Terminal bronchioles in T. S. 



5. Openings, E, E, which are about the same size and bear a 

 general resemblance to those of Obs. 2. (Note that their internal 

 edges are smooth and not ragged. They are terminal bronchi- 

 oles. No larger bronchial tubes have been included in the 

 section.) 



