THE ENGLISH SPARROW. 



6. Just behind the costal processes, a pair of conspicu- 

 ous, slender lateral xiphoid processes, arising from the 

 lateral margins of the body, and extending obliquely 

 backward, to partially inclose a pair of triangular spaces 

 which were in life closed by membrane. 



IV. The Shoulder Girdle. Study the shoulder girdle. 

 Each half of it consists of the three usual bones, meeting 

 to form the shoulder. 



1. The scapula is a long, thin, and narrow bone, shaped 

 somewhat like a sled runner, extended backward from the 

 shoulder above the ribs. It is enlarged to form articular 

 facets at the shoulder, and sharply pointed at the posterior 

 end. 



2. The coracoid is a stout, straight bone set in between 

 the shoulder and the front of the sternum. How does 

 its direction correspond with the direction in which the 

 pectoral muscles pull ? 



3. The clavicle is a slender bone, shaped like a fishhook, 

 with the hook turned toward the sternum. It is anchy- 

 losed at its hook end with its fellow of the opposite side, 

 and the two together are commonly known as the fur- 

 culum (merrythought, or wishbone). 



V. Wing Bones. Study the bones of the wing. 



1. The humerus is the single stout bone of the arm. 



2. The radius and ulna are the two bones of the fore- 

 arm. They are entirely separate. The ulna is much the 

 stouter. It has a blunt proximal (olecranori) process pro- 

 jecting back of the elbow joint, and its posterior edge is 

 roughened for the attachment of the bases of the second- 

 ary quills. 



3. The carpal, metacarpal, and pJialangeal bones are 

 peculiarly anchylosed in the adult. Two carpal bones 

 remain free at the distal end of radius and ulna. Three 

 distal carpal bones have fused with three metacarpals to 

 form a conspicuous single bone, the carpo-metacarpus. 



