212 



ANATOMY OF VERTEBEATES. 



receptacle by two openings at the anterior part of the lungs. The 

 deep-seated air-cells of the neck are continued from it anteriorly. 

 The lateral thoracic cells, ib. d, are continued on each side 

 from a foramen on the inner edge of the lung, situated just 

 opposite the base of the heart ; they are covered by the anterior 

 thoracic air-cell, and from them the air passes into the axil- 

 lary and suhscajnilar cells, into 

 those of the wing, and into 

 the humerus, ib. e. They also 

 communicate with the cellula 

 cordis posterior, ib. c, behind 



98 



the heart and 



bronchi, which 



into 



cell is often subdivided 

 several small ones. 



The cellulce hepaticce are of 

 much larger size ; they are two 

 in number, of a pyramidal 

 figure, with their bases applied 

 to the lateral thoracic cells, and 

 their apices reaching to the 

 pelvis : they cover the lower 

 portions of the lungs and the 

 lobes of the liver ; they receive 

 air from several foramina situ- 

 ated near and at the external 

 edo^e of the lunors. 



The cellulcB ahdominales com- 

 mence beneath the cellular he- 

 patlcte at the inferior extremity 

 of the lungs, where the longest 

 branches of the bronchi^e open 

 freely into them. (A bristle is 

 passed through one of these 

 openings in the figure.) They 

 are distinguished into right Qi) 

 and left {f) : the former is ge- 

 nerally the largest receptacle in the body ; it extends from the 

 last ribs to the anus, and covers the greater part of the small in- 

 testines, the suprarenal gland, and kidney of the same side. The 

 left abdominal cell, f, contains the intestines of its own side, and 

 is attached to the gizzard. In some large Birds, as the Gannet, it 

 is separated from the right receptacle by a mediastinal membrane, 

 g, which is continued on from the gizzard to the anus. 





Air-receptacles of a Swan. 



