The successive order of what may be termed foot fallings are these. Commencing with the landing of the left hind foot, the next to strike the ground will be the left fore foot, followed in order by the right hind, and right fore foot. So far as the camera has revealed, these successive foot fallings during the walk are invariable, and are probably common to all quadrupeds. But the time during which each foot, in its relation to the other feet, remains on the ground, varies greatly with different species of animals, and even with the same animal under different conditions. During an ordinary walk, at the instant preceding the striking of the left hind foot, the body is supported on the right laterals, and the left fore foot is in act of passing to the front of the right fore foot. The two hind feet and the right fore foot immediately divide the weight. The right hind foot is now raised, and the left hind with its diagonal fore foot sustains the body; the left fore next touches the ground and for an instant the animal is again on three feet; the right fore foot is immediately raised and again the support is derived from laterals--the left instead of as before the right. One half of the stride is now completed, and a similar series of alternations, substituting the right feet for the left, completes the other half. These movements will perhaps be more readily understood by a reference to the longitudinal elevation, Fig. 7, No. 1, which illustrates some approximate relative positions of the feet of a rapid walking horse, with a stride of 5 feet 9 inches. The positions of the feet indicated in this, and also in the other strides illustrated in Fig. 7 are copied from photographs, and from them we learn that during an ordinary walk the consecutive supporting feet are: 1. The left hind and left fore--_laterals_. 2. Both hind, and left fore. 3. Right hind and left fore--_diagonals_. 4. Right hind and both fore. 5. Right hind and right fore--_laterals_. 6. Both hind, and right fore. 7. Left hind and right fore--_diagonals_. 8. Left hind and both fore. [Illustration: LONGITUDINAL ELEVATION OF SOME CONSECUTIVE POSITIONS OF THE FEET OF HORSES DURING VARIOUS MOVEMENTS. Each line illustrates a single complete stride. The comparative distances of the feet from each other, or from the ground, are approximate; not to scale. Direction of movement --> _KEY._ _Rt._ _Left._ _Hind Feet_ _Fore Feet_ _Line of ground_ Length of Action. Stride. 1 2 3 4 5 6 1D 2D 3D 4D 5D 6D ft. in. 1. Walking 5 9 2. Trotting 7 6 3. " 17 6 4. " 18 3 5. Ambling 10 3 6. Racking 12 6 1 2 3 4 5 6 7 8 9 10 11 12 7. Cantering 10 3 8. Galloping 11 9 9. " 19 9 10. Galloping, a conjectural stride } of 22 feet or more } ]