rse of formation, and _posteriorly_ a
perfectly normal cartilage. It is to the latter half of the cartilage that
dealers and others mainly, if not wholly, devote their attention. A horse
with the cartilage in this transition state will therefore pass muster, and
a nice little point of ethics has again to be decided by the veterinary
surgeon before giving his signature to a certificate of examination of an
animal in this condition.

With regard to alteration in gait, we may say at once that side-bones in
heavy animals are not often the cause of lameness. In fact, where the foot
is well developed, when neither the foot as a whole nor the phalangeal
bones give evidence of disease, and where the pasterns are fairly oblique
and well formed, this alteration of the cartilages may be looked upon as of
no serious import at all. Neither is the side-bone due to blows or other
injuries likely to be productive of lameness--that is, always supposing, of
course, that the foot in other respects is of good shape. If lameness is
met with at all, then it is where we have a foot that is in other respects
unsound, with badly contracted heels and upright 'stumpy' hoof, or where
side-bones have occurred in a young animal, and have already reached a
large size before the horse is put to labour. In this latter case, the
added effects of concussion and the evil influences of shoeing are
sufficient to turn the scale. Directly the animal, previously sound, is
asked to work, lameness is the result.

It follows, therefore, that side-bone in the feet of young animals is of
far more serious import than when occurring in older horses. In a nag
animal they constitute a positive unsoundness, and lameness in this case is
more often than not an accompanying symptom.

_Causes_.--To commence with, we may remark that, although met with
sometimes in very early life, side-bones are seldom, if ever, congenital,
and that more often than not they may be looked for in animals of three
years old, or older, seldom earlier. They appear, in fact, only when the
animal is shod and commences work.

This at once suggests two of the principal factors in their
causation--namely, concussion and loss of normal function. Directly the
horse is put to work he has for a great part of his time to travel upon
roadways--either macadamized roads or town sets--where everything is
calculated to bring concussion about. In addition to that he has the
lateral cartilage itself thrown lar