THE BIRD’S SKELETON 293 
The hind limbs of the bird represent more modifications and a 
greater number of bones. The tibia is the principal bone, while 
the most noticeable characteristic is the fused tarsus and meta- 
ay 
“ee, Bi 
Ee Bm EP 
Ls 
After Edward Brown. 
Fia. 141.—Skeleton of fowl. 1, Upper jaw; 2, lower jaw; 3, nasal cavity; 4, eye cavity; 
5, skull; 6, neck vertebre; 7, scapula; 8, clavicles (wish bone); 9, digits; 10, bones of fore- 
wing; 11, ulna; 12, radius; 13, humerus; 14, backbone; 15, ribs; 16, femur; 17, acetabulum; 
18, ischium; 19, pygostyle or tail bones; 20, breastbone or sternum; 21, tibia; 22, tarso- 
metarsus; 23, spur; 24, rear toe; 25, toes. 
tarsus. The thigh bones are exceedingly short, and when the 
bird is in full plumage are never seen. The fowl normally has only 
four toes. The fifth one is missing. (The Dorking and Houdan 
