jury and disease, the synovial fluid is
secreted in large quantities, and distends the sac of the joint. This
affection is called dropsy of the joint, and occurs most frequently in
that of the knee.

125. The function of the ligaments is to connect and bind together the
bones of the system. By them the small bones of the wrist and foot, as
well as the large bones, are as securely fastened as if retained by
clasps of steel. Some of them are situated within the joints, like a
central cord, or pivot, (3, fig. 26.) Some surround it like a hood,
and contain the lubricating synovial fluid, (8, 9, fig. 25,) and some
in the form of bands at the side, (5, 6, fig. 23.)

[Illustration: Fig. 25. 8, 9, The ligaments that extend from the hip-bone
(6) to the femur, (5.)]

[Illustration: Fig. 26. 2, The socket of the hip-joint. 5, The head of
the femur, which is lodged in the socket. 3, The ligament within the
socket.]

126. By the ligaments the lower jaw is bound to the temporal bones,
and the head to the neck. They extend the whole length of the spinal
column, in powerful bands, on the outer surface, between the spinal
bones, and from one spinous process to another. They bind the ribs to
the vertebrae, to the transverse process behind, and to the sternum in
front; and this to the clavicle; and this to the first rib and
scapula; and this last to the humerus.

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What is the effect when the synovial fluid is secreted in large
quantities? 125. What is the function of the ligaments? 126. Mention
how the bones of the system are connected.

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127. They also bind the two bones of the fore-arm at the elbow-joint;
and these to the wrist; and these to each other and to those of the
hand; and these last to each other and to those of the fingers and
thumb. In the same manner, they bind the bones of the pelvis together;
and these to the femur; and this to the two bones of the leg and
patella; and so on, to the ankle, foot, and toes, as in the upper
extremities.

[Illustration: Fig. 27. 1, A front view of the lateral ligaments of the
finger-joints. 2, A view of the anterior ligaments (_a_, _b_,) of the
finger-joints. 3, A side view of the lateral ligaments of the finger
joints.]

128. The different joints vary in range of movement, and in complexity
of structure. Some permit motions in all directions, as the shoulder;
some move in two directions, permitting only flexion and extension