56 Vertebrata. 



in front a prominent keel, to which the muscles which 

 elevate and depress the wing are attached, and this is 

 only absent in such birds as do not fly, as the ostrich, 

 emu, and New Zealand ground parrot. The wings 

 are fastened to a very strong shoulder-girdle, which 

 consists of three parts ; firstly, of a V-shaped furculum, 

 or merrythought, which consists of the two collar- 

 bones united together in the middle line ; secondly, 

 FIG. 23. of the coracoid bone, a stout 



bony rod which fits into a 

 groove in the top of the 

 breast-bone and stretches 

 from thence upwards and 

 backwards to the shoulder 

 joint ; thirdly, the scapula, or 

 scythe-blade-like bone, which 

 j joints with the coracoid at 

 the shoulder, and descends 

 backwards over the dorsal 

 ribs, slung in its place by 

 muscles. The wing bones 

 consist of, firstly, an arm 

 bone, or humerus ; secondly, 

 Pelvis of bird. two forearm bones ; thirdly, 



a, sacrum ; b, lumbar vertebras ; i i j i i 



d, ilium ; /, pubis ; g, sciatic a consolidated hand made 

 up of several (never more 



than four) united fingers, of which only the thumb in 

 general bears a claw, rarely the thumb and index 

 fingers, as in the cassowary. The ribs are few and 

 are fastened together by lateral spurs, or processes. 

 The portions of the ribs which articulate with the 

 vertebral column are separate from those that unite 

 with the breast bone. 



