36 THK VETERINARY SCIENCE 
joint through which the muscle plays there may be found a 
small, puffy enlargement containing oil secreted by the syno- 
vial membrane. This disease is called a bursal enlargement. 
The flexor muscles are situated at the back part of the 
leg, attached above to the back part of the elbow joint, pass- 
ing downwards at the back part of the leg. About two or 
three inches above the back part of the knee joint they be- 
come tendinous, and from there down to the back part of 
the foot bone, where two of the principal muscles are at- 
tached ; these form what is known as the back tendons, or 
cords, of the leg. Some of them become attached to the back 
part of the knee, same as the muscles on the front part of 
the leg, while ,the other two principal tendons pass through 
a loop formed by ligaments, the same as those mentioned in 
the front part of the knee. In tracing these tendons down 
from the knee to the fetlock, notice that they pass through 
another large loop or sheath formed at the back of the fet- 
lock, where some of the fibres are attached, while others con- 
tinue down at the back part of the pastern bones, and are at- 
tached to the OS pedis, or foot bone. These tendons are im- 
portant, because when they are strained the tact is spoken 
of as the strain of the back tendons. The action of these 
muscles is to flex the leg, bend the knee, pastern joints and 
fetlock. 
7. Muscles of Hind Leg. — These are also divided into 
two groups, extensor and flexor. 
The extensor muscles are situated in front of the hind 
leg. They are attached above, around the stifle joint, and 
pass downward in front of the thigh bone, one being attached 
to the front part of the hock. The other passes through 
sheaths, or loops, supplied by a synovial membrane, formed 
by ligaments, to hold the muscles firm in front while the leg 
is in action. In tracing them down, in front of the shin bone 
to the fetlock, note that they pass through loops, or sheaths, 
and continue down in front of the pastern bones to where 
they are attached. The action of these is to bring the leg 
forward. 
The flexor muscles of the hind leg are attached, above, 
around the back part of the stifle joint. In tracing them 
down it will be found that they become tendonous. Two of 
the principal ones pass down to that part of the hock joint, 
which sticks up behind, known as the cap. These form what 
