ble, as they are then easily shelled out after
incising the overlying skin; sometimes splitting the cyst makes its
removal easier. Local anaesthesia is to be preferred. It is important
that none of the cyst wall be left behind. In large and adherent wens an
ellipse of skin is removed along with the cyst. When inflamed, it may be
impossible to dissect out the cyst, and the wall should be destroyed
with carbolic acid, the resulting wound being treated by the open
method.

#Moles.#--The term mole is applied to a pigmented, and usually hairy,
patch of skin, present at or appearing shortly after birth. The colour
varies from brown to black, according to the amount of melanin pigment
present. The lesion consists in an overgrowth of epidermis which often
presents an alveolar arrangement. Moles vary greatly in size: some are
mere dots, others are as large as the palm of the hand, and occasionally
a mole covers half the face. In addition to being unsightly, they bleed
freely when abraded, are liable to ulcerate from friction and pressure,
and occasionally become the starting-point of melanotic cancer. Rodent
cancer sometimes originates in the slightly pigmented moles met with on
the face. Overgrowths in relation to the cutaneous nerves, especially
the plexiform neuroma, occasionally originate in pigmented moles. Soldau
believes that the pigmentation and overgrowth of the epidermis in moles
are associated with, and probably result from, a fibromatosis of the
cutaneous nerves.

_Treatment._--The quickest way to get rid of a mole is to excise it; if
the edges of the gap cannot be brought together with sutures, recourse
should be had to grafting. In large hairy moles of the face whose size
forbids excision, radium or the X-rays should be employed. Excellent
results have been obtained by refrigeration with solid carbon dioxide.
In children and women with delicate skin, applications of from ten to
thirty seconds suffice. In persons with coarse skin an application of
one minute may be necessary, and it may have to be repeated.

#Horns.#--The _sebaceous_ horn results from the accumulation of the
dried contents of a wen on the surface of the skin: the sebaceous
material after drying up becomes cornified, and as fresh material is
added to the base the horn increases in length (Fig. 100). The _wart_
horn grows from a warty papilloma of the skin. _Cicatrix_ horns are
formed by the heaping up of epidermis in the scars that result from
bur