18 



vertebrae, and formed of three irregularly shaped bones on each 

 side, united at the bottom, and forming a cavity occupied by the 

 bladder and the rectum; the femur, united vnth the pelvis, 

 forms the hip joint; the femur, tibia, and patella form the stifle 

 joint; the tibia, tarsus (six bones) , and the metatarsal bones form 

 the hook joint; the metatarsal, os suifraginis, and two sesamoids 

 form the fetlock joint; below this the bones and joints are the 

 same as in the fore leg. 



JOINTS AND LIGAMENTS. 



The joints are all formed between two or more separate bones, 

 having a soft elastic substance interposed, whose structure varies 

 with the amount of motion. Where this is extensive, as in the 

 joints of the limbs, the adjacent surfaces are covered vnth a 

 peculiar kind of cartilage arranged in a thin and very smooth 

 layer upon them. In addition to this protsction against friction 

 and vibration the bones are firmly bound together by strong 

 bands of white, fibrous, inelastic tissue under the general name 

 of ligaments. A lubricating fluid (called synovia) is required to 

 reduce the amount of friction; and to produce it, as well as to 

 keep it within proper limits, a membrane (synovial) is developed. 

 In the neck much greater freedom of motion is required to admit 

 of lowering the head in grazing and the raising of it for various 

 purposes, as well as for balancing its great weight at all times. 

 Lateral flexion and rotation on its own axis are also necessitated 

 for the purpose of directing the muzzle right or left of the 

 straight line; and for these several movements the following 

 ligament (hgamentum nuchse) is provided: 



The ligamentum nuchse is formed entirely of yellow, elastic 

 tissue, and occupies the angle formed posteriorly by the anterior 

 dorsal spines and inferiorly by the cervical spinous process, thus 

 separating the cervical muscles of the right side from those of 

 the left. 



Capsular ligaments are fibrous structures inclosing joints, their 

 use being to form cavities around them inclosing and protecting 

 the synovial or lubricating apparatus inside. 



The suspensory ligament should be carefully studied on 

 account of the numerous accidents to which it is liable. It is a 

 long, strong band of fibrous tissue arising in the back part of 

 the lower bones of the carpus (knee) and the upper part of the 



