CHAPTEE lY. 



THE SKELETON OF THE LIMBS. 



1. The skeleton of the limbs, or appendicular skeleton, is divisible 

 into the skeleton of the anterior, thoracic or pectoral limbs, and that 

 of the posterior abdominal or pelvic limbs. 



THE SKELETON OF THE PECTOKAL LIMB. 



The bones of the cat's pectoral limb belong to three categories : 

 A. those of the shoulder ; B. those of the fore-leg ; and C. those of 

 the paw. 



A. Those of the shoulder are the blade-bone, called the sca^mla, 

 and the collar-bone, called the clavicle. These, with their 

 fellows of the opposite side, constitute what is called the 

 shonider-girdle. 



B. Those of the fore-leg are subdivisible into (a) the bone of the 

 part above the elbow, called the humerus, and (6) the bones of the 

 part below the elbow, called respectively the radius and the ulna. 



C. Those of the paw are divisible into three sets : (a) the bones 

 of the wrist, called in anatomy the carpus ; (h) those of the 

 middle solid part of the paw, called the metacarpus ; and 

 (c) those of the toes (or digits), which are called 2:>ha/aii(/es. 



§ 2 The scAPiTLA is a Hat, somewhat triangular bone, with three 

 borders and two surfaces. One border is anterior, one is superior, 

 and one is posterior. The superior border (Fig. 51, r) is also called 

 '^ vertebra I," because it is the one nearest to the vertebral column. 

 The posterior border {x) is also called " axillar//," because it is 

 adjacent to the axilla, or arm-pit. Of its surfaces, one is applied 

 against the ribs, and is concave ; it is called the subscapular fossa, 

 and affords attachment to the subscapularis muscle. It presents one 

 or two oblique ridges. 



The other (dorsal or outer) surface is divided obliquely into two 

 unequal parts by a prominent ridge, called the spine (s), on which 

 account tlie smaller part in front of the ridge is termed the supra- 

 spijious fossa (ss), and the part behind it (is) the ivfra-spinous fossa. 

 These spaces are occupied by correspondingly named muscles. 



The spine of the scapula becomes graduaUy more prominent from 

 the vertebral border of the bone, while at its outer end the spine 



