STKUCTUEE OF THE HORSE. 87 



vertical position between the humerus and carpus. Tliis bone 

 is frequently called the arm. It is the longest bone of the fore 

 leg. On the supero-posterior part of this bone is a triangular 

 bone, the ulna. Next in order is the carpus, or knee, composed 

 of seven and often of eight small, irregular bones, arranged in 

 two rows of three each, one above the other, the seventh being 

 at the back of the three in the upper row, and the eighth, when 

 present, in a similar position with respect to the lower row. 

 Naming from within outwards, the bones of the upper row are 

 the scaphoid. Inner, and cuneiform, and the trapezium behind 

 the latter; those of the lower row are the trapezoid, os magnum, 

 and unciform, and the pisiform behind the trapezoid. The next 

 are the large and two small metacarpals, corresponding to the 

 bone that lies between the wrist and finger of the human. Below 

 this is the phalanges, consisting of three bones, which are homo- 

 logous to the three phalanges of the human finger, and having 

 two sesamoid bones placed behind. In descending the os suffra- 

 ginis comes first, os coronse second, and lastly the os pedis. The 

 navicular, or shuttle bone, is situated, with its long axis trans- 

 versely, behind and below the os corona? and behind the os pedis, 

 with both of which it articulates. The posterior extremity is 

 united to the trunk by the direct articulation of the pelvic arch 

 with the femur and sacral vertebra. The entire arch is called 

 the OS innominatum, or pelvis. The os innominatum is divided 

 into three parts — the ilium, ischium, and pubis. The first bone 

 of the hind extremity is the femur, or thigh bone. It is the 

 largest, thickest, and strongest bone in the l)ody. The patella, 

 the kne^ pan, or stifle bone, is placed in front of the trochlea of 

 the femur. The tibia, or shin bone, is situated between the 

 femur and astragalus, slanting downwards and backwards. The 

 fibula is a little, long slender bone, attached to the outer side of 

 the tibia. The tarsus, or hock, corresponds to the ankle joint of 

 man, and is composed of six bones arranged in two series — one 

 consisting of the cuboid and three cuneiform bones, the magnum, 

 medium, and parvum. The other, the upper series, consists of 



