PLEASURES OF ORNITHOLOGY. 35 



The Rectrices; (0 the Tectrices (2) to shield ; 

 All harmonise together and display 

 Of elegance their undulating curves. 



To osseous structure singular go thence : 

 I'he sternum^ (') with Carina (^) high and long 

 To hold the muscles of the active wing ; 

 Where medulla of mammals flows, in birds, 

 Is air ; while through the hollow trunk extend 

 Vessels which that elastic fluid hold 

 To raise, depress, at will, the buoyant whole. 



The Gastric apparatus now invite 

 Your deep attention. First, the Ingluvies\^) note— 

 Primal recipient where each substance finds 

 Its proper pre-concoction ; next observe 

 The Proventriculus,(^) of many shapes 



(I) Rectrices. The quill feathers of the tail, which serve as ; 

 rudder to direct the flight of the bird.— (2) Tectrices, The small 

 feathers which cover the bird, and of course protect it.— 

 (3) Sternum. The breast bone.— (*) Carina. The keel, or pro- 

 jection of the sternum, designed doubtless for the attachment 

 of powerful muscles in those birds which fly. The Ostrich, not 

 flying, has no carina in the sternum.— C) Ingluvies. The crop. 

 —(6) Proventriculus. The upper entrance to the gizzard in 

 birds ; it is of various shapes in different birds ; in it are nume- 

 rous glands which secrete a liquor that appears analogous to the 

 gastric juice of the mammalian tribes. 



