ue fragility of the bones dates from intra-uterine life. It
may occur in several members of the same family. In severe cases,
intra-uterine fractures occur, and during parturition fresh fractures
are almost sure to be produced, so that at birth there is a combination
of recent fractures and old fractures united and partly united, with
bendings and thickenings of the bones. Large areas of the cranial vault
may remain membranous.

After birth the predisposition to fracture continues, the bones are
easily broken, the fractures are attended with little or no pain, the
crepitus is soft, and although union may take place, it may be delayed
and be attended with excess of callus. Cases have been observed in which
a child has sustained over a hundred fractures.

The bones show a feeble shadow with the X-rays, and appear thin and
atrophied; the medullary canal is increased at the expense of the
cortex.

In young infants in whom multiple fractures occur the prognosis as to
life is unfavourable, and no satisfactory treatment of the disease has
been formulated. If the patient survives, the tendency to fracture
gradually disappears.

#Hypertrophic Pulmonary Osteo-Arthropathy.#--This condition, which was
described by Marie in 1890, is secondary to disease in the chest, such
as chronic phthisis, empyema, bronchiectasis, or sarcoma of the lung.
There is symmetrical enlargement and deformity of the hands and feet;
the shafts of the bones are thickened, and the soft tissues of the
terminal segments of the digits hypertrophied. The fingers come to
resemble drum-sticks, and the thumb the clapper of a bell. The nails are
convex, and incurved at their free ends, suggesting a resemblance to the
beak of a parrot. There is also enlargement of the lower ends of the
bones of the forearm and leg, and effusion into the wrist and
ankle-joints. Skiagrams of the hands and feet show a deposit of new bone
along the shafts of the phalanges.

TUMOURS OF BONE

New growths which originate in the skeleton are spoken of as _primary
tumours_; those which invade the bones, either by metastasis from other
parts of the body or by spread from adjacent tissues, as _secondary_. A
tumour of bone may grow from the cellular elements of the periosteum,
the marrow, or the epiphysial cartilage.

Primary tumours are of the connective-tissue type, and are usually
solitary, although certain forms, such as the chondroma, may be multiple
from the outset.

_Perioste