ns. _Nail_ horns are overgrown nails (keratomata of the nail bed),
and are met with chiefly in the great toe of elderly bedridden patients.
If an ulcer forms at the base of a horn, it may prove the starting-point
of epithelioma, and for this reason, as well as for others, horns should
be removed.

[Illustration: FIG. 100.--Sebaceous Horn growing from Auricle.

(Dr. Kenneth Maclachan's case.)]

#New Growths in the Skin and Subcutaneous Tissue.#--The _Angioma_ has
been described with diseases of blood vessels. _Fibroma._--Various types
of fibroma occur in the skin. A soft pedunculated fibroma, about the
size of a pea, is commonly met with, especially on the neck and trunk;
it is usually solitary, and is easily removed with scissors. The
multiple, soft fibroma known as _molluscum fibrosum_, which depends upon
a neuro-fibromatosis of the cutaneous nerves, is described with the
tumours of nerves. Hard fibromas occurring singly or in groups may be
met with, especially in the skin of the buttock, and may present a local
malignancy, recurring after removal like the "recurrent fibroid" of
Paget. The "painful subcutaneous nodule" is a solitary fibroma related
to one of the cutaneous nerves. The hard fibroma known as _keloid_ is
described with the affections of scars.

#Papilloma.#--The _common wart_ or verruca is an outgrowth of the
surface epidermis. It may be sessile or pedunculated hard or soft. The
surface may be smooth, or fissured and foliated like a cauliflower, or
it may be divided up into a number of spines. Warts are met with chiefly
on the hands, and are often multiple, occurring in clusters or in
successive crops. Multiple warts appear to result from some contagion,
the nature of which is unknown; they sometimes occur in an epidemic form
among school-children, and show a remarkable tendency to disappear
spontaneously. The solitary flat-topped wart which occurs on the face
of old people may, if irritated, become the seat of epithelioma. A warty
growth of the epidermis is a frequent accompaniment of moles and of that
variety of lupus known as _lupus verrucosus_.

_Treatment._--In the multiple warts of children the health should be
braced up by a change to the seaside. A dusting-powder, consisting of
boracic acid with 5 per cent. salicylic acid, may be rubbed into the
hands after washing and drying. The persistent warts of young adults
should be excised after freezing with chloride of ethyl. When cutting is
objected