MANUAL FOR STABLE SERGEANTS. 15 



(c) The lumbar region consists of six bones forming the skeleton of 

 the loins. 



(d) In the sacral region there are five segments which become 

 united to form a single bone, the sacrum. 



- (e) The coccygeal vertebrae are the last of the series. They number 

 from 13 to 20 and form the skeleton of the tail. 



(/) Throughout the length of this bony chain from the atlas to the 

 fourth coccygeal vertebra, inclusive, is a tubular passage called the 

 spinal canal, which is continuous with the cranium and which con- 

 tains the spinal cord. 



7. The bony thorax (chest) is a large cavity formed by the 

 thoracic vertebrae above, tho ribs on the sides and the sternum 

 (breast bone) below. It contains the lungs, the heart, some large 

 blood vessels and nerves, and a part of the trachea and the esophagus. 



8. The ribs are 18 on each side, and are attached above to the 

 thoracic vertebrae. Below, the first eight are attached to the 

 sternum by means of cartilage, and are called true or sternal ribs. 

 The remaining 10 are attached indirectly to the sternum and are 

 called false or asternal ribs. 



9. The bones of the fore limb, named from above downward, 

 are the scapula, humerus, radius, and ulna; the carpus (knee) consist- 

 ing of seven or eight small bones; the large metacarpal (cannon) bone; 

 two small metacarpal (splint) bones; the^rs phalanx (long pastern 

 bone); the second phalanx (short pastern bone); the third phalanx 

 (coffin bone); two proximal sesamoids, and the distal sesamoid or navi- 

 cular bone. 



10. The bones of the hind limb, named from above downward, 

 are the os coxae (hip bone) , femur (thigh), tibia, fibula, and patella 

 (stifle); the tarsus (hock), consisting of six or seven small bones; the 

 targe metatarsal (cannon bone); the two small metatarsals (splint 

 bones); the first phalanx (long pastern bone); the second phalanx 

 (short pastern bone); the third phalanx (coffin bone); two proximal 

 sesamoids, and the distal sesamoid or navicular bone. 



11. The os coxae (hip bone) consists of three parts, the ilium 

 ischium, and pubis, all of which meet and unite to form a large cup- 

 shaped cavity for articulation with the head of the femur. The right . 

 and left hip bones are connected above with the sacrum and below 

 they are united with each other to form the floor of the pelvic cavity. 

 This bony arch, together with the first three coccygeal vertebrae, is 

 called the pelvis and forms the framework of the hips and croup. 



