wo ends by a solid cicatrix, the callus, or the ends will
continue separated or become only partially united by an intermediate
fibrous structure. In the first instance the fracture is consolidated or
united; in the second there is a false articulation, or pseudarthrosis.

The time required for a firm union or true consolidation of a fracture
varies with the character of the bone affected, the age and constitution
of the patient, and the general conditions of the case. The union will
be perfected earlier in a young than in an adult animal, and sooner in
the latter than in the aged, and a general healthy condition is, of
course, in every respect, an advantage.

The mode of cicatrization, or method of repair in lesions of the bones,
has been a subject of much study among investigators in pathology, and
has elicited various expressions of opinion from those high in
authority. The weight of evidence and preponderance of opinion are about
settled in favor of the theory that the law of reparation is the same
for both the hard and the soft tissues. In one case a simple exudation
of material, with the proper organization of newly formed tissue, will
bring about a union by the first intention, and in another the work will
be accompanied with suppuration, or union by the second intention, a
process so familiar in the repair of the soft structures by granulation.

Considering the process in its simplest form, in a case in which it
advances without interruption or complication to a favorable result, it
may probably be correctly described in this wise:

On the occurrence of the injury an effusion of blood takes place between
the ends of the bone. The coagulation of the fluid soon follows, and
this, after a few days, undergoes absorption. There is then an excess of
inflammation in the surrounding structure, which soon spreads to the
bony tissue, when a true ostitis is established, and the compact tissue
of the bone becomes the seat of a new vascular organization, and of a
certain exudation of plastic lymph, appearing between the periosteum and
the external surface of the bone, as well as on the inner side of the
medullary cavity. After a few days the ends of the bone thus surrounded
by this exudate become involved in it, and the lymph, becoming vascular,
is soon transformed into cartilaginous, and in due time into bony,
tissue.

Thus the time required for the consolidation of the fractured segments
is divisible into two distinct