the rider has no direct action on the shoulders. He acts only on the neck through the mouth, and on the shoulders through the neck. Lateral flexion, by strengthening and binding all the parts together, places them in a state of reciprocal dependence, which enables the rider to act on the entire forehand. Without flexion, the fishing-rod, as I have already said, will be held by the thin end ; that is to say, there will be a heavy head (because it is far from the centre of gravity) at the end of a slack neck. The action of the reins, instead of directing the mass, is therefore limited to bringing the head towards the forehand, which remains fixed on the ground, in proportion as the horse is on his shoulders.

Fig. 33. — Correct lateral flexion.

3. To preserve lightness in the changes of direction by the flexion of the jaw.

In all movements, impulsion makes the horse a single whole.