RESPIRATION. 



461 



Fig. 130. (WATERS) Is a drawing of a thin slice, cut transversely, of tne lung of 

 a cat. It shows the shape of the air sacs. This drawing was taken by aieans of the 

 camera, in the same way as the last three, a a, are the cut air sacs, Vhe dark parts 

 their walls. 



a 



Fig. 131. Theoretical view of the pulmonary tissue, viz., terminal bronchial tube, its 

 dilated extremity, and its group of air sacs or lobulettes, divided transversely, a, Ter- 

 minal bronchial tube ; 6, Cavity in which the air sacs end ; c c, The air sacs (the central 

 one is ?een to divide). The markings denote the alveoli of the air sacs, and of the 

 dilated extremity of the bronchial tube. 



