492 
LECTURES ON HORSES. 
way to the foot, a long lever may make a difference of some pounds 
even in the capabilities of the fore-limb. So far as progression is 
assisted by the fore extremities, it is by the action of the powerful 
muscles inserted into the elbows : while the flexors of the arm 
have only to lift the limb off the ground and advance it, the exten- 
sor muscles — attached to the elbow — have, the moment the foot is 
grounded, to aid in the grand operation of progression. We see, then, 
the necessity for long and prominent elbows. Some horses appear 
as if they had no elbows : the protuberances are either so short or 
stand so upright, that they are not perceptible to the eye, and can 
hardly be felt ; which I look upon, myself, as a great deficiency, 
though it is one that, even by “judges,” is not at all times noticed. 
People invariably pay great attention to hocks; but seem to over- 
look elbows ; as I said before, however, for my own part, I do think 
that length and form of elbow is a point of considerable importance, 
and as such, I never lose sight of it. 
At mature age, the arm of the horse is composed of a single 
bone — the radius : the ulna being, in truth, but a process. And the 
radius is a bone of superior strength, its great length, with the 
weight and shocks, and muscular action it has to sustain, requiring 
that it should be so. Two smaller bones of the same length would 
have been too liable to fracture. Entering into the structure of the 
fore limb are two long straight shafts of support : the radius consti- 
tutes the uppermost of these, the cannon or leg bone the under- 
most ; all the other supporters being angularly disposed. 
The radius in itself, however, is not a mathematically straight 
bone : between one extremity and the other it is slightly curved, 
after the manner of a bow, the convexity of which is presented 
forwards ; so that were it placed upon a table or any level surface, 
with its hinder part turned downward, it would form a very ex- 
tended arc ; and this shape it is which renders it remarkable be- 
yond any other bone in the horse. Thus fashioned, as a column of 
support it is capable of sustaining greater weight, or at all events 
greater shocks, from a property, which as a sort of bow it must 
ppssess, of elasticity. What are called “ calf-legs” do not arise 
from any deficiency of this bow of the radius, but from peculiar 
formation of the knee-joints. 
Superiorly, the radius is connected with the humerus, the nature 
of the joint formed between them being such as admits of flexion 
forwards and again of extension, but neither of flexion backwards 
nor of any lateral motion. A horse has the power of advancing 
his arm, and raising it rather beyond the line of right angle with 
his body ; but he cannot bend it in a backward direction : the limb 
is extended backward through the motion of the humerus on the 
scapula. Had the elbow-joint moved backward as well as for- 
ward, the animal m-ust have been so insecure upon his legs, that 
