17th. Crevasses: Fissures. These are chaps, which extend into the derma, giving rise to destruction of tissue and leaving a cicatrix on healing. Examples are found in the hollow of the pastern, behind the knee (Mallenders), in front of the hock (Sallanders), in the swellings of petechial fever, malignant catarrh, stocked legs, grease, etc.
18th. Ulcus: Ulcer. A sore that extends by the continual molecular breaking down of the forming granulations and of the adjacent and subjacent diseased tissue.
19th. Excrescences: Hyperplasiæ: Phymata: Dermatomata. These may include over luxuriant granulations which rise above the level of the skin and become organized into projecting fibro-cellular, raw or scabby masses: tumors of all kinds—warty, papillomatous, horny, epidermic, cancerous, sarcomatous, pigmentary, angeiomatous, tuberculosis, etc.
20th. Cicatrices: Scars. These are puckered, raised or sometimes depressed, lines or areas of condensed connective tissue with a covering of epidermis, taking the place of the normal dermis and epidermis and their appendages, which have been destroyed. They result from traumatic, ulcerous, or atrophic destruction of the skin.
21st. Neurosis. These may be exemplified by the intense itching of the skin without appreciable structural change. So in cutaneous anæsthesia and hyperæthesia.
22d. Modified Secretions. These include absence of perspiration—anidrosis, excessive perspiration—hyperidrosis, suppressed sebaceous secretion—asteatosis, excessive sebaceous secretion—steatorrhea or seborrhea, fœtid sweat—bromidrosis, colored sweat—chromidrosis, urinous sweat—uridrosis.
23d. Structural alterations in glands and ducts. Cystic ducts—hydrocystoma, blocked ducts—acne, inflamed glands—hidrosadenitis.
24th. Abnormal conditions of the hair. This embraces baldness, hypotrichosis, alopecia, excessive growth of hair, hypertrichosis, white patches, canities, nodular hairs, piedra, brittle hair, fragilitas crinium, felted hair, plica, trichoma.
25th. Scleroderma. Hard, leathery, thickened skin. Examples in old boars on shoulders, and in other animals.
26th. Elephantiasis Pachydermia. Enormous hypertrophy of the skin, with usually distention of the lymph plexuses and vessels (lymphangiectasis: see Vol. I).