The data available in the literature concerning fish thrombocytes, lymphocytes, monocytes, macrophages and granulocytes is discussed and the dearth of reliable information concerning the functional identity of most fish leucocytes is underlined. The methods of applying nomenclatures to fish leucocytes encountered in the literature is discussed in some detail and found to be unsatisfactory. An attempt is made to simplify the confused and conflicting reports by applying the concepts which have recently arisen in the field of mammalian immunology. Nomenclatures are assigned to cells on a functional and morphological basis where sufficient data exists.

Thrombocytes are responsible for clot formation and are considered to be distinct, separate and unrelated to lymphocytes. Lymphocytes are recognised as immuno-competent cells though as yet little information exists on their role in immune mechanisms. Recent work is furnishing interesting results in this direction, especially in the origin of lymphocyte populations and their co-operative responses in immunity. Previous references to monocytes and macrophages in fish are confused and the literature is discussed in the light of the new classification of the Mononuclear Phagocyte System.

Very few experimental data exist concerning granulocytic leucocytes in fish, indeed the presence of such cells with granulocytic functions still requires proof. Cells with morphological similarity to mammalian granulocytes do exist in fish but information essential for an understanding of their role in defence mechanisms is lacking. The state of the literature concerning the eosinophil, basophil and mast cell in fish is so confused that an entirely new approach to a study of these cells is warranted. It is hoped that this review will supply guidelines for future research.

The leucocytes of fish: A review

http://www.klinikum-dessau.de/fileadmin/user_upload/Hautklinik/PDF-Files/235_clinder-acne-etiol.pdf

Acne and sebaceous gland function

Fish immunity and parasite infections: from innate immunity to immunoprophylactic prospects.

Inflammatory cells of teleostean fish: A review focusing on mast cells/eosinophilic granule cells and rodlet cells

The natural history of cancer

Studies on the skin of plaice (Pleuronectes platessa L.). 1. The structure and ultrastructure of normal plaice skin

Familial primary self-healing squamous epithelioma of the skin

WHEN Shattock, in 1916, investigated the pathology of Nitch's case of a firm rounded tumour of the lower lip in a male who eleven years previously had suffered a cut on the lip as a result of a cycle accident, he advocated the retention of the term \" pseudo-tuberculoma \" for nodular lesions of noninfective origin histologically simulating tuberculosis. He described '' close congeries of large multinuclear giant cells, of giant cell systems, and of aggregates of systems such as construct the miliary tubercle of a tubercular focus.*' The giant cells were of striking size, and scattered throughout the section were transparent, angular, colourless particles, which were highly refractile under polarized Light and which proved to be siliceous in origin, thus being in keeping with foreign bodies introduced at the time of the accident. Clinically the lesion had been found to be a firm rounded tumour with the overlying skin freely movable. No mention was made of any change in the colour or consistence of the skin. Faulds (1935) reported two cases of similar type, 23 and 10 years respectively after injury, the lesions being firm tumours of cartilaginous consistence, tender but non-inflammatory, with no visible overlying scars. X-ray examination of the first case revealed a small foreign body, the source of which was proved beyond doubt. In the second case optically active crystals w êre demonstrated. No mention in either case is made of any alteration in the overlying skin. No evidence of tubercle could be traced, but the histologieal structure resembled closely that of a tubercular condition. Eden and Herbert-Burns (1936) reported a case following a fall on a flinty road 16 years previously. In this case a tender nodule developed beneath the scar of the original injury, the lesion having slowly formed during the three months prior to examination. The nodule was the size of a hazel nut, firm but slightly fluctuant, and attached to the scar and to the deep fascia. At

Pseudo-tuberculoma silicoticum

Intracutaneous bulla formation. ("polythene bag bullae").

SIMPLE symptomatic exfoliative states ma}' respond dramatically to treatment with steroids and reticulosis as manifested in acute lymphoblastic leukaemia may show temporary regression with such therapy. Reticulosis of the skin, which often presents as exfoliative dermatitis, might accordingly be expected to show response to the administration of adrenocortical hormones. Temporary diminution of pruritus and improvement in tlie skin have been noted in occasional cases of mycosis fungoides by Tulipan (1950), Taylor et al. (1950), Schuppli (1951), Costello (1951), Steiner and Frank (1952), Hopkins et al. (1952), Miescher (1952), Kierland et al. (1952) and others. Ingram (1956) foimd that pruritus and infiltration were diminished in some cases, but Lever (1951), Goldsmith and Hellier (1954) and Degos (1955) considered that steroids are of little value in the management of mycosis fungoides. The histological appearances in the premycotic stage of this disease may be such that the diagnosis rests upon opinion short of proof, and the natural course of this singular eruption makes it difficult to assess the respoiise to treatment. Bearing these considerations in mind, we present the results of steroid treatment in ten patients in whom the diagnosis of early mycosis fungoides appeared probable on clinical and histological grounds, and in one patient who was suffering from reticulosarcoma. Clinical and histological details are given in Tables I and II.

J. A. Milne

Papers

Studies on the skin of plaice (Pleuronectes platessa L.). 1. The structure and ultrastructure of normal plaice skin

Familial primary self-healing squamous epithelioma of the skin

Pseudo-tuberculoma silicoticum

Intracutaneous bulla formation. ("polythene bag bullae").

Steroid therapy in reticulosis of the skin with special reference to exfoliative dermatitis.