THE ANATOMY OF THE HORSE 35 
support to the organs contained in the abdominal cavity. The 
action, or uses, of the abdominal muscles are to support the 
organs contained in the abdominal cavity, to flex the back- 
bone and assist in the passing of the faeces, or manure. In 
the mare these muscles assist her in foaling, or parturition. 
4. The Coccygeal, or Muscles of the Tail. — Here there 
are four that are important — one situated on the upper side 
of the tail when it is straight out, the action of which is to 
raise the tail ; two, one on each side of the tail, have the 
power of drawing the tail to either side ; the fourth is situ- 
ated under the tail and is the smallest one of the four. Its 
action is to draw the tail down. 
5. The Shoulder Muscles are very large and powerful. 
There are only three of great importance, viz. : Two situated 
on the outside of the shoulder blade are important as they 
are the muscles affected in the disease called sweeny. The 
other important one is that which passes down over the 
shoulder joint through the groove or pulley-like surface on 
the shoulder bone. This is a long, powerful muscle, attached 
above to the lower end of the shoulder blade, down through 
the groove mentioned to the upper part of the bone to the 
fore arm, or radius, .at the front side. Its chief point of im- 
portance rests in its action in raising the front leg, where it 
passes through the pulley-like surface mentioned, when it 
becomes injured or diseased; it is the seat of shoulder joint 
lameness. 
6. Muscles of Front Leg, from shoulder down, are divided 
into two separate kinds, viz. : the extensor and flexor muscles. 
The extensor muscles are those which bring the leg for- 
ward. These muscles, above, are attached to the bones 
around the elbow joint, passing down in front of the arm 
bones. About three inches above the knee they become 
changed into the tendinous part of these muscles, or what is 
called the cords of the leg. Some of them are attached to 
the knee joint, while others pass over the front of the joint 
and are held down to their place by a band or ligament, 
forming a loop, as it were, for this muscle to glide into when 
the leg is in action. Each one of these loops through which 
the muscles pass are supplied with a synovial membrane to 
secrete the synovia, or oil, which lubricate ii dunng action, 
the same as in the joint. This is a point of importance, as 
sometimes, on account of injury or strain of this part of the 
