186 COMPENDIUM OF THE VETERINARY ART. 



or nut bone: the forniei' are connected pos- 

 teriorly with the lower extremity of the can- 

 non, or shank bone : they consist of two small 

 bones, firmly united by means of very strong 

 ligaments; they compose part of the fetlock 

 joint, having a movable articulation with the 

 cannon bone. Their external part affords a 

 smooth poHshed surface for the back sinews 

 to slide upon, and the same ligament which 

 composes this surface comes round the back 

 sinews, so as to form a sheath for them, and 

 keep them in their situation. In this sheath a 

 fluid similar to synovia, or joint oil, is formed, 

 for the purpose of rendering it smooth and 

 slippery, and enabling the tendon to move 

 easily upon it. As these bones project a 

 little, they serve as a pulley for the tendons 

 to slide upon, and afford a considerable me- 

 chanical advantai>:e to the flexor muscles of 

 the limb. The nut bone serves as another 

 pulley for the tendon or back sinew to move 

 upon : it is connected posteriorly with the 

 coffin bone and the small pastern, and affords 

 the same kind of polished surface and sheath 

 for the tendon as we iiave before described. 



