36 SKETCH OF THE ANATOMY OF THE HORSE. 



behind the fourth or fifth vertebra of the tail, have a canal in which 

 the spinal cord lies. Their joints have more or less power of movement, 

 except those of the croup, which, in the grown-up horse, form a solid 

 bony mass. 



The withers are the long spines of the seven or eight dorsal vertebrae 

 which come after the first. The spine of the fifth dorsal vertebra forms 

 the summit of the withers. 



On each side there are eighteen ribs (eight true and ten false) at- 

 tached to the dorsal vertebrae. Both kinds have pieces of cartilage 

 attached to their lower ends. The true ribs are connected by their 

 respective cartilages with the breast-bone ; but the false ones are only 

 indirectly connected to it, the cartilage of the first false rib resting on 

 that of the last true one ; that of the second false rib, on the first false 

 one ; and so on. 



The fore limb, according to Chauveau and other veterinary anato- 

 mists, consists of the shoulder-blade, humerus, bones of the fore-arm, 

 knee, cannon-bone, splint bones, long pastern bone, short pastern 

 bone, pedal (coffin) bone, two small bones at the back of the fetlock 

 (sesamoid bones), and the navicular bone, which lies at the back of 

 the joint formed by the short pastern bone and pedal bone. Enghsh 

 comparative anatomists consider that it is incorrect to include the 

 shoulder-blade among the bones of the fore-leg ; but, in discussing 

 conformation, it is well to do so, on account of the very important part 

 which it plays in the movements of that limb. 



The shoulder-blade {scapula) is a broad, thin bone, which is flat on 

 its inside surface and has a narrow ridge of bone (the spine of the scapula) 

 on its outer surface. This spine serves as a partition to divide the 

 muscles which extend the shoulder joint from those that flex it. The 

 humerits is the bone which lies between the shoulder joint and the elbow 

 joint. 



There are two bones of the fore-arm, namely, the radius, which 

 makes a joint with the humerus and with the bones of the knee ; and 

 the ulna, which is lyiited to the back and upper part of the radius, 

 above which it projects. The upper part of the ulna is called the 

 olecranon, the top of which is termed the point of the elbow. 



There are two rows of bones of the knee, at the back of which a bone 

 (the pisiform) is placed. It is curved inwards so as to form a groove 

 for the passage of the back-tendons of the fore-leg. 



The two splint bones are placed at the back of the cannon-bone, one 

 on the outside, the other on the inside. They form a groove in which 

 lies the upper portion of the suspensory ligament. 



There is a joint between the cannon-bone and the long pastern bone, 

 between the two pastern ]-)ones, and between the short pastern bone and 

 the pedal {coffin) bone. The navicular bone articulates with both 



