212 MANUAL OF MODERN FARRIERY 



therefore analogically regarded as the carpus, so in 

 like manner the hock becomes the correspondent 

 part to the instep, and is consequently considered 

 under the technical appellation of tarsus. It consists 

 of six small bones. 



a. The astragalus, or knuckle bone. Its form is like that 

 of a pulle)^. Its surface consists of two bold semi- 

 circular prominences, with a deep capacious groove 

 between them ; these are admirably adapted to the 

 two grooves, parted by their middle projection in the 

 lower extremity of the tibia, and these opposite 

 prominences and grooves are received, and as it were 

 morticed into each other. At the posterior part its 

 convex surface is received into a concavity near the 

 base of another bone, and with which it is united 

 by very strong ligaments to the os calcis, c, or bone 

 of the heel, and it projects upwards, flattened at the 

 sides, and receives into it the tendons of powerful 

 muscles, which are strongly implanted into it. The 

 lower surface is smaller than either of the others, 

 and is irregularly flattened, and almost wholly 

 articulatory ; it is embraced by the superior part 

 of the large cuneiform bone. The two bones above 

 described rest on two others, the os cuboides, or cube- 

 shaped bone, , behind, and the larger wedge-shaped 

 bone, </, in front. This larger wedge-shaped bone is 

 supported by two small ones,/, and these two smaller 

 ones and the cube-shaped bone by the upper heads of 

 the shank bone, ^, and the splint bone, g. The cube 

 bone is placed on the external splint bone and the 

 cannon bone ; the small wedge bone chiefly rests on 

 the inner splint bone, which cannot be seen in our 

 figure, and the middle wedge bone rests on the 

 shank bone, h, alone. All these bones are connected 

 together by very strong ligaments, which prevent dis- 

 location, but are sufficiently flexible to allow a slight 

 degree of motion among them, and the surfaces 

 which are opposed to and move upon each other are 

 thickly covered by elastic cartilage. 



b, The inferior end or base of the tibia. This bone reaches 



