38 THE STRUCTURE OF THE FOWL 



occupied by the pectoral muscle. In addition, 

 part of it arises from the broad distal end of 

 the clavicle, and from the membrane between 

 this bone and the sternum. A strong, rounded 

 tendon passes through the foramen triosseum, 

 and is inserted into the humerus on that side 

 of the greater tubercle immediately opposite 

 to the attachment of the pectoral muscle. 

 The action of the supracoracoid muscle is to 

 raise the wing by producing a rotation of the 

 humerus. 



Associated with the muscular apparatus of 

 the wing is a fold of skin, the ptagium, stretching 

 from the trunk to the arm, and filling the 

 angle between the arm and the forearm. 

 Within the fold is an elastic membrane and 

 muscular tissue, these being concerned in 

 folding the wing after it has been outstretched. 



The numerous muscles of the leg offer the 

 peculiarity that ossification is of common 

 occurrence within the long tendons of those 

 which move the toes. Another feature of 

 some moment is an arrangement by which the 

 toes are mechanically flexed when the inter- 

 tarsal joint is bent, whereby the fowl grasps 

 the perch without effort. It is generally stated 

 that the ambiens muscle plays an important 



