SUPERFICIAL DISSECTIONS 13 



distance of about twelve inches in the living animal, bone is 

 again found to be superficially placed, and here we have the ex- 

 ternal malleolus of the tibia, which presents a well-marked vertical 

 groove for the passage of the tendon of the peroneus muscle (23). 

 The outer lateral surface of the astragalus is situate below the 

 malleolus, and behind these two elevations is the prominent tuber 

 calcis. This is concealed by the tendon of the perforatus, which is 

 here very much flattened (22). Inferiorly to the calcis is the cuboid, 

 and below this again we have the head of the outer small metatarsal 

 bone (29). Extending obliquely downwards and forwards from the head 

 is the body of the last-mentioned bone, which gradually tapers from 

 above downwards. It terminates inferiorly in the rounded nodule 

 termed the button, which is placed about two inches above the fetlock 

 joint (35). The button is easily located in the living animal, since 

 between it and the large metatarsal bone there is a slight interval, and \>, A 

 the button springs a little upon the application of pressure. 5 oJ 



In front of the small metatarsal bone is a groove down which -f^ <d 

 the large metatarsal artery runs. The groove is bounded anteriorly ^ O 

 by the large metatarsal bone. The greater part of the lateral surface ui • 

 of this bone is visible in the plate, and in the living animal is d '^ 

 immediately subcutaneous (33). ■;^ 



The sesamoid bones are concealed from view by the broadened- 

 out perforatus tendon and the lateral division of the suspensory 

 ligament, but below the fetlock a considerable portion of the lateral 

 surface of the sufFraginis is represented, as is also the tuberous 

 lateral aspect of its inferior extremity. 



The Ligaments 



The External Straight Patellar Ligament {ja). — This ligament runs 

 downwards in a vertical direction from the anterior surface of the 

 patella to the outer division of the anterior tuberosity of the tibia. In 



