[Ill.u.s.tration: FIG. 143.--THE LEAP.]
One sudden trigger action produced by the violent contraction of the extensors of the hind-legs then takes place, and the animal is projected forwards, while he flexes the fore-legs more and more (Fig. 139). He has then risen above the obstacle (Fig. 140). Then while he makes the downward and forward balancing movement, and points his fore-limbs in the same direction, he flexes the hind ones (Fig. 141). Whilst the latter are further flexed, in order to pa.s.s the obstacle in their turn, the fore-limbs which are extended come into contact with the ground (Fig. 142). Finally, in the last phase of the leap, the animal, raising himself in front, after the impact of his hind-feet has taken place (Fig. 143), prepares to continue the pace at which he progressed before meeting the obstacle which he had to clear.
THE END