310 



ANATOMICAL TECHNOLOGY. 



glands ; it is also a temporary organ and may be entirely absent in 

 old animals. Its function is not well understood. 



References to the Lung-s. Quain, A, II, 289 ; Gray, A, 827 ; Chauveau, A, 493 ; 

 Chauveau (Fleming), A, 466 ; Leyh, A, 444 ; Owen, A, III, 572 ; Cuvier, A, VII, 19 ; 

 Hyrtl, A, 306 ; Gegenbaur, A, 572 ; Milne-Edwards, A, II, 334 ; Williams (T.), A, V, 258. 



GL&ss tute. 



cock* 

 ExnatLSttabe. 



hep stopper. 

 Thread 



809. Pulmo Lung (Fig. 

 77, 89, 99, 100). On each side 

 of the thorax, extending from 

 the diaphragm to the first rib, 

 will be seen a sponge-like mass. 

 Each of these masses is a lung ; 

 and the two are the essential or- 

 gans of respiration. Insert a 

 glass tube or a flexible blow-pipe 

 into the trachea and inflate the 

 lung. The trachea must be 

 pressed closely against the tube 

 to prevent the escape of air. 



810. Lobes. Each half of 

 the inflated lung will be seen to 

 consist of several divisions, the so 

 called lobes. There are three on 

 each side cephalic, intermediate 

 or middle, and caudal (Fig. 89). 

 Azygous Lobe.-- T Yhs right 

 lung, in addition to the three 

 lobes mentioned in the preceding 

 paragraph, has a small one, the 

 azygous lobe, projecting into a 

 kind of pocket formed of pleura, 

 dorso-caudad of the apex of the 

 heart and between it and the dia- 

 phragm (Fig. 77, 103, C. 1., az.). 

 The free edge of this pocket is 



bounded by the postcava. This lobe is sometimes deeply divided 



into two, the caudal of which is the larger. 



811. Alveoli. Hold an edge of the inflated lung between the 

 eye and the light, and note that it is divided into spaces about 1 mm. 

 in diameter. These are the air sacs or alveoli ( 813, 814). 



FIG. 89. LUNGS AND TRACHEA ; x .2. 

 (The apparatus is arranged as for an 

 experiment ; see Wilder, 2 



