46 EXAMINATION OF HORSES 
over a right angle; that is, instead of being 90°, it is 
about 95°. (See Fig. 1,%.) 
This lower angle being wnalterable by any movement 
or position, it follows that where the phalanges bend in 
either way, it is at the expense of the upper angle or 
that formed by the pasterns with the top of the hoof; 
and it was shown that in a state of rigidity of the limb, 
or when the horse was standing fully upon it, that this 
angle was 5° /ess than a right angle (85°), the other angle 
below it being 5° more ; therefore when bent, as when a. 
horse is trotting, galloping, or jumping, and gathering 
his limbs well under him, this angle is still less; or in’ 
other words it is this angle which is alterable. 
The lowermost phalangeal bone (0s pedis) bears a 
constant unalterable relation to our /ower angle, because 
it is fixed in the hoof; and we have seen that the lower’ 
angle is altogether formed by the hoof. 
We have also seen that ina state of great rigidity of 
the limb, as when the weight of the body is thrown 
forwards upon it in sleep, or when in motion, that the 
column of bones, from the pedal joint to the elbow 
joint, becomes one rigid column, practically as stiff and 
unyielding as if it were made of iron. It is a rigid bent 
lever having a very long arm and a very short arm. 
(See Fig. 2.) 
This being so, we have the foot below on the one 
hand, and the whole leg above on the other, as two rigid 
pieces, with their juncture and yielding point at the 
coffin joint—the joint with the tendinous yielding stay. 
