THE SKELETON AND ANATOMY OF BIRDS. 



371 



except the first and last pair. There is a large breast-bone or 

 sternum (14). In flying birds this sternum has a deep sternal 

 ridge or keel, to which are attached the powerful muscles which 

 move the wings. The pectoral arch (fig. 210) consists of a 

 pair of soapulffi (Sc), clavicles (/), and coracoid bones (Co). The 



d 



Fig. 211.— Sternum of Fowl (front view). 



a, Keel; &, manubrium; c, oblique lateral process; d, anterior lateral process; e, 

 posterior lateral process ; f, internal notch ; g, >3xternal uotcli. 



scapula is an elongated simple bone ; the coracoids are distinct 

 and very strong, and articulate with the upper angle of the 

 sternum ; the clavicles form the V-shaped bone popularly called 

 the " merry-thought." 



