tissue
for future grafting, it should be embedded in the subcutaneous tissue of
the abdominal wall until it is wanted; this has been carried out with
portions of costal cartilage and of bone.

INDIVIDUAL TISSUES AS GRAFTS

#The Blood# lends itself in an ideal manner to transplantation, or, as
it has long been called, _transfusion_. Being always a homoplastic
transfer, the new blood is not always tolerated by the old, in which
case biochemical changes occur, resulting in haemolysis, which
corresponds to the disintegration of other unsuccessful homoplastic
grafts. (See article on Transfusion, _Op. Surg._, p. 37.)

#The Skin.#--The skin was the first tissue to be used for grafting
purposes, and it is still employed with greater frequency than any
other, as lesions causing defects of skin are extremely common and
without the aid of grafts are tedious in healing.

Skin grafts may be applied to a raw surface or to one that is covered
with granulations.

_Skin grafting of raw surfaces_ is commonly indicated after operations
for malignant disease in which considerable areas of skin must be
sacrificed, and after accidents, such as avulsion of the scalp by
machinery.

_Skin grafting of granulating surfaces_ is chiefly employed to promote
healing in the large defects of skin caused by severe burns; the
grafting is carried out when the surface is covered by a uniform layer
of healthy granulations and before the inevitable contraction of scar
tissue makes itself manifest. Before applying the grafts it is usual to
scrape away the granulations until the young fibrous tissue underneath
is exposed, but, if the granulations are healthy and can be rendered
aseptic, the grafts may be placed on them directly.

If it is decided to scrape away the granulations, the oozing must be
arrested by pressure with a pad of gauze, a sheet of dental rubber or
green protective is placed next the raw surface to prevent the gauze
adhering and starting the bleeding afresh when it is removed.

#Methods of Skin-Grafting.#--Two methods are employed: one in which the
epidermis is mainly or exclusively employed--epidermis or epithelial
grafting; the other, in which the graft consists of the whole thickness
of the true skin--cutis-grafting.

_Epidermis or Epithelial Grafting._--The method introduced by the late
Professor Thiersch of Leipsic is that almost universally practised. It
consists in transplanting strips of epidermis shaved from the surface