ability of the foot than of any other part of the
extremities to injury from casualties, natural to its situation and use,
should always suggest the beginning of an inquiry, especially in an
obscure case of lameness at that point. Indeed the lameness may have an
apparent location elsewhere when that is the true seat of the trouble,
and the surgeon who, while examining his lame patient, discovers a
ringbone, and convincing himself that he has encountered the cause of
the disordered action suspends his investigation without subjecting the
foot to a close scrutiny, at a later day when regrets will avail
nothing, may deeply regret his neglect and inadvertence. As in human
pathological experience, however, there are instances when inscrutable
diseases will deliver their fatal messages, while leaving no mark and
making no sign by which they might be identified and classified, so it
will happen that in the humbler animals the onset and progress of
mysterious and unrecognizable ailments will at times baffle the most
skilled veterinarian, and leave our burden-bearing servants to succumb
to the inevitable, and suffer and perish in unrelieved distress.

DISEASES OF BONES.

PERIOSTITIS, OSTITIS, AND EXOSTOSIS.

From the closeness and intimacy of the connection existing between the
two principal elements of the bony structure while in health, it
frequently becomes exceedingly difficult, when a state of disease has
supervened, to discriminate accurately as to the part primarily affected
and to determine positively whether the periosteum or the body of the
bone is originally implicated. Yet a knowledge of the fact is often of
the first importance, in order to obtain a favorable result from the
treatment to be instituted. It is, however, quite evident that in a
majority of instances the bony growths which so frequently appear on the
surface of their structure, to which the general term of exostosis is
applied, have had their origin in an inflammation of the periosteum, or
enveloping membrane, and known as periostitis. However this may be, we
have as a frequent result, sometimes on the body of the bone, sometimes
at the extremities, and sometimes involving the articulation itself,
certain bony growths, or exostoses, known otherwise by the term of
splint, ringbone, and spavin, all of which, in an important sense, may
be finally referred to the periosteum as their nutrient source and
support, at least after their formation, if not for