ion of the bone at the ossifying junction,
the epiphysis is liable to be separated--_epiphysiolysis_. The
separation usually takes place through the young bone of the ossifying
junction, and the surfaces of the diaphysis and epiphysis are opposed to
each other by irregular eroded surfaces bathed in pus. The separated
epiphysis may be kept in place by the periosteum, but when this has been
detached by the formation of pus beneath it, the epiphysis is liable to
be displaced by muscular action or by some movement of the limb, or it
is the diaphysis that is displaced, for example, the lower end of the
diaphysis of the femur may be projected into the popliteal space.

The epiphysial cartilage usually continues its bone-forming functions,
but when it has been seriously damaged or displaced, the further growth
of the bone in length may be interfered with. Sometimes the separated
and displaced epiphysis dies and constitutes a sequestrum.

The adjacent joint may become filled at an early stage with a serous
effusion, which may be sterile. When the cocci gain access to the joint,
the lesion assumes the characters of a purulent arthritis, which, from
its frequency during the earlier years of life, has been called _the
acute arthritis of infants_.

Separation of an epiphysis nearly always results in infection and
destruction of the adjacent joint.

Osteomyelitis is rare in the bones of the carpus and tarsus, and the
associated joints are usually infected from the outset. In flat bones,
such as the skull, the scapula, or the ilium, suppuration usually occurs
on both aspects of the bone as well as in the marrow.

_Clinical Features._--The constitutional symptoms, which are due to the
associated toxaemia, vary considerably in different cases. In mild cases
they may be so slight as to escape recognition. In exceptionally severe
cases the patient may succumb before there are obvious signs of the
localisation of the staphylococci in the bone marrow. In average cases
the temperature rises rapidly with a rigor and runs an irregular course
with morning remissions, there is marked general illness accompanied by
headache, vomiting, and sometimes delirium.

The local manifestations are pain and tenderness in relation to one of
the long bones; the pain may be so severe as to prevent sleep and to
cause the child to cry out. Tenderness on pressure over the bone is the
most valuable diagnostic sign. At a later stage there is an ill-defined
s