d becomes
incorporated with the bone with which it is in contact, and does not
merely act as a scaffolding. We believe also that the retention of the
periosteum on the graft is not essential, but, by favouring the
establishment of vascular connections, it contributes to the survival of
the graft and the success of the transplantation. Macewen maintains that
bone grafts "take" better if broken up into small fragments; we regard
this as unnecessary. Bone grafts yield better functional results when
they are immovably fixed to the adjacent bone by suture, pegs, or
plates. As in all grafting procedures, asepsis is essential.

Transplanted bone retains its vitality when embedded in the soft parts,
but is gradually absorbed and replaced by fibrous tissue.

DISEASES OF BONE

The morbid processes met with in bone originate in the same way and lead
to the same results as do similar processes in other tissues. The
structural peculiarities of bone, however, and the important changes
which take place in the skeleton during the period of growth, modify
certain of the clinical and pathological features.

_Definition of Terms._--Any diseased process that affects the periosteum
is spoken of as _periostitis_; the term _osteomyelitis_ is employed when
it is located in the marrow. The term _epiphysitis_ has been applied to
an inflammatory process in two distinct situations--namely, the
ossifying nucleus in the epiphysis, and the ossifying junction or
metaphysis between the epiphysial cartilage and the diaphysis. We shall
restrict the term to inflammation in the first of these situations.
Inflammation at the ossifying junction is included under the term
osteomyelitis.

The term _rarefying ostitis_ is applied to any process that is attended
with excessive absorption of the framework of a bone, whereby it becomes
more porous or spongy than it was before, a condition known as
_osteoporosis_.

The term _caries_ is employed to indicate any diseased process
associated with crumbling away of the trabecular framework of a bone. It
may be considered as the equivalent of ulceration or molecular
destruction in the soft parts. The carious process is preceded by the
formation of granulation tissue in the marrow or periosteum, which eats
away and replaces the bone in contact with it. The subsequent
degeneration and death of the granulation tissue under the necrotic
influence of bacterial toxins results in disintegration and crumbling
away of th