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brae, have their internal substance divided into in- 

 numerable cells ; while others, as the shoulder and 

 thigh bones, are hollowed out into one large canal, 

 with sometimes a few bony columns running across at 

 the extremities ; and, at that end of the bones next to 

 the trunk of the bird, several holes or openings are 

 placed. There are openings in the lungs, by which 

 the air they receive is transmitted to other parts ; 

 and the diaphragm also is perforated with holes of a 

 considerable size, to 'each of which is joined a dis- 

 tinct membranous bag, which, being continued 

 through the whole of the abdomen, is retained in its 

 proper situation, by being attached to the back or 

 sides of that cavity. Each bag receives air from the 

 lungs through its respective opening, and such bags 

 extend over the whole abdomen. At their superior 

 part, the lungs communicate with the large cells 

 of a loose net-work, situated on the anterior part of 

 the breast ; and when these are distended with air, 

 the size of the part is considerably increased, as is 

 plainly seen in the turkey-cock, the pouting pigeon, 

 and in the breast of the goose when she cackles. 

 These cells in the breast communicate with others in 

 the axilla, which again communicate with the os hu- 

 meri, by small openings near the head of that bone. 

 The posterior edges of the lungs open into the cells 

 of the bodies of the vertebras, into those of the ribs, 

 the canal of the spinal marrow, and into the cells of 

 the bones of the pelvis, from which parts the air 

 finds a passage into the cavity of the thigh bone. 

 Thus, the cells, situated in the soft parts and in the 

 bones of birds, can be furnished with air through 

 the medium of the lungs. 



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