702 



MAMMALIAN ANATOMY 



FIG. 538. 



Vertebral Column. 



Hi/oid. 



Clavicle. 

 Sternum. 



Metacarpus. 



Metatarsus. 

 Phalanges. 



FIG. 539. 



LEFT PATELLA, ANTERIOR SURFACE. 



THE SKELETON OF THE CAT. (LEFT SIDE ONLY.) 



greatest antero-posterior diameter is about half as great as the great- 

 est transverse diameter. Its thickest and widest part is a little below 



the upper end. It has an anterior and 

 a posterior surface, one upper and two 

 lateral borders, and a lower angle. 



The anterior surface is bounded by 

 an arcuate, transverse superior margin 

 and more gradually arcuate lateral 

 margins, which are directed downward 

 and inward to meet at the lower angle 

 of the two lateral borders ; of these two borders the external is the 

 straighter. 



From above downward the anterior surface is strongly convex, and 

 its upper part, which arches backward and upward to the superior 

 border, is slightly convex in the middle and flat or concave below. 

 From side to side it is gently convex, except at the upper extremity, 

 where it is more decidedly arched. This upper part, which comprises 

 about a fifth of the whole surface, is rough and receives the insertion 

 of most of the fibres of the tendon of the quadriceps extensor. The 

 flatter middle part of the surface is almost subcutaneous, and gives 

 attachment to the upper fibres of the part of the tendon which joins the 

 patella to the tibia. This tendon, known as the ligamentum patellae, 

 arises mainly from the lower part of the anterior surface, which is 

 roughened, and from the lower angle, which is slightly upturned. 



