1 June, 1902.] QUEENSLAND AGRICULTURAL JOURNAL. 483 
Animal Pathology. 
WARTS. 
By WILMOT C. QUINNELL, M.R.C.V.S., Government Veterinary Inspector, 
Warts (sometimes known in surgery by their Latin name Verruce) are 
collections of lengthened papille of the skin, closely adherent and ensheathed 
by a thick covering of hard, dry cuticle. From friction and exposure of the air 
their surface presents a horny texture. They occcur in all veterinary subjects, 
most common in young animals. 
Before treating of these excrescences, we will say a few words to explain 
the structure and function of the skin in health. 
The skin, or integument, is the outer enveloping membrane ot the body, 
and continuous with the outer limits of the internal mucous membranes. It 
consists of two distinct layers, of which the outer is termed the epidermis 
cuticle, scarf-skin, or false skin; and the inner the derma, chorion, cutis vera, 
or true skin. 
The upper skin is destitute of blood vessels and nerves, as may be seen by 
inserting a needle under it, and it is the part separated in a blister. It grows 
from pew upwards, end is continually being shed in the form of minute scales 
(scurf). ; 
If a large portion of the epidermis be removed, the process of repair is 
slow and proceeds from the edges of the wound, but recovery is quicker if any of 
the deeper cells of the layer remain. Skin-grafting aims at transplanting small 
portions of healthy epidermis—including its deeper layers—to denuded surfaces, 
and when the grafts take root the raw surface is much more speedily covered 
because the healing process spreads from each graft. The epidermis, being 
impermeable to moisture, serves to protect the living tissues beneath it against 
the absorption of poisons. Whenit is perfect, poisonous substances may be 
freely handled; but these substances are readily absorbed into the blood when 
the cuticle is cut, or when a small portion of it has been torn off. 
The dermis, true skin (cutis vera), consists of fibres of connective and 
elastic tissue, interwoven with minute blood-vessels and nerve fibres. Its 
surface is drawn up into finger-like projections called papille, the largest of 
which are about one-hundredth of an inch in length. 
These little eminences are more or less conical, or sometimes club-shaped. 
They may be compound, and contain a capillary loop, nerve, and touch- 
corpuscle ; they project into the epidermis, and by raising it up, as it were, from 
a ridge on the surface of the skin, they serve to increase the sensitiveness of 
the part, lodging a touch-corpuscle or ‘tactile corpuscle” in a favourable 
position so that the properties of bodies are revealed to the sense of touch. 
Regarded as a protective covering, the skin possesses the combined 
advantages of toughness, resistance, flexibility, and elasticity; the connective 
frame being the part which mainly confers these properties, although the 
epidermis co-operates with it. 
The sub-cutaneous layer of fat (fill up all the irregularities of surface in the 
underlying parts, and give the rounded form and plumpness to the surface of the 
body), and the modification of the epidermis in yarious forms, as hairs, wool,, 
Peniteon scales, &c., serve for the preservation of warmth, and occasionally 
(when they occur as claws, talons, &c.), as means of offence or defence. 
The appendages of the skin are the hairs, sudoriferous and sebaceous glands: 
and horny parts. 
The hairs are modifications of skin, and are divided into the hair proper,. 
forming the coat, coarse hair, long and flowing, found in the forelock, mane, 
tail, eyelashes, lips, and fetlock. ‘The hairs also furnish protection against wet, 
from the fact that they are always more or less oily, from the secretions of the 
sebaceous glands, and thus shed water. The hairs through their elasticity 
furnish mechanical protection, and through the thickness of the coat, to a 
certain degree, resist the attacks of insects. Finally, the hairs assist the sense: 
of touch. Smknes ae tt 
