25>2 



THE PIGEON 



At the point of union of the clavicles the furcula is laterally compressed 

 to form the episternum. The upper end of each clavicle is attached 

 by ligaments to the acromion process of the scapula and to the acro- 

 coracoid process of the coracoid. 



(b) The large coracoids, already noted, articulate with the sternum at their 



broad bases, which connect the shoulder-girdle firmly with the 

 sternum. The other end of each coracoid has an articular surface 

 and is produced into an acro-coracoid process. 



(c) The scapula is a thin blade-like bone situated above the ribs and parallel 



to the backbone. It is connected with the coracoid at its anterior 

 end, which has a shallow articular cavity and is produced into a small 

 process. Note the foramen triosseum, formed by the conjoined upper 

 ends of the coracoid, clavicle and scapula. The articular surfaces of 

 the coracoid and scapula form the glenoid cavity. 



Antitrochanter 

 Ilium \ Ischiatic foramen 



--Ilium 



Scapula 



Clavicle 



Manubrium-- 

 Episternum' 



Acetabulum. 



Obturator foramen 

 Uncinate process 



B. 



-Sternal part 

 'Xiphoid process 



Posterior xiphoid process 



Fontanelle 



Fig. 88.— a. The Pectoral Girdle, Sternum and Ribs ; and B. the Pelvic Girdle of 

 the Pigeon {Columba). 



2. The Fore-limb. 



Detach a fore-limb (wing) and note the following bones : — ■ 



(a) The humerus, enlarged at its proximal end to form the prominent 

 head, which articulates with the glenoid cavity. Note the deltoid ridge, 

 on which the pectoral and deltoid muscles are inserted, and the 

 pneumatic foramen, a deep depression opening into a pneumatic 

 cavity in the shaft of the humerus. 



(6) The radius, a slender and almost straight bone. 



(c) The ulna, lying parallel to the radius, a larger and curved bone pro- 

 longed proximally as the olecranon process. The shaft of the ulna 

 bears the marks of the secondary feathers. 



