MANUAL OF MODERN FARRIERY. 
w. This is the extensor of the leg ; it is the principal one of the 
fore arm, is of considerable bulk, and occupies the front part 
of the arm. It takes its rise from the lower portion of the 
body of the lower bone of the shoulder, and from its outer 
head. As it descends down the arm, it becomes tendinous. 
This tendon passes under one of the ligaments of the knee; 
it then spreads out, and is inserted into the fore and superior 
portion of the shank-bone. It is also seen at e, fig. 2. 
x. The middle flexor, or bending muscle of the shank-bone. 
This is situated immediately on the middle of the back part of 
the arm. It arises from the inner termination of the lower 
bone of the shoulder, and is continued and inserted into one of 
the bones on the inner side of the knee. It is also seen at e, 
% 2 . 
2. The external flexor of the leg, and which is situated on the 
outer side of the arm, towards the back. It has its origin in 
the outer head of the lower bone of the shoulder, stretching 
towards the knee. It is of a tendinous character, and divides 
into two portions, one of which is inserted into the same bone 
of the knee, and the other into the outer small bone of the leg. 
8, And extending down to 7, 4, and 5, are the principal artery, 
nerve, and vein of the leg. 
7. This is the perforated flexor muscle. It arises from the lower 
and back portion of the inner head of the lower bone of the 
shoulder, and is intimately intermixed with the perforating 
flexor muscle. As it descends along the bone of the arm, it 
becomes tendinous, and extending to the knee, it is bound 
down by ligamentary bands to prevent it from starting in sud¬ 
den or violent motion. From the knee it widens and partly 
laps round the tendon of the perforating muscle; they then 
descend together in contact, but are not adherent, sliding over 
each other freely and safely by the aid of the lubricating fluid. 
They are both encircled in a thick sheath of cellular substance 
which is attached to them by numerous small fibres. Reach¬ 
ing near to the fetlock, the tendon expands still more, forming 
a complete ring round the tendon of the perforating muscle. 
This is shown at k, plate vi. fig. 7. The perforated tendon 
soon divides, and is inserted into the larger and smaller pastern- 
bones, its office being to bend them. 
8 The subcutaneous vein of the side of the chest. 
