_In man_ also the clinical features of the chronic variety of the disease are somewhat different from those of the acute form. Here, too, infection takes place through a broken cutaneous surface, and leads to a superficial lymphangitis with nodular thickening of the lymphatics (_farcy buds_). The neighbouring glands soon become swollen and indurated. The primary lesion meanwhile inflames, suppurates, and, after breaking down, leaves a large, irregular ulcer with thickened edges and a foul, purulent or bloody discharge. The glands break down in the same way, and lead to wide destruction of skin, and the resulting sinuses and ulcers are exceedingly intractable. Secondary deposits in the subcutaneous tissue, the muscles, and other parts, are not uncommon, and the nasal mucous membrane may become involved. The disease often runs a chronic course, extending to four or five months, or even longer. Recovery takes place in about 50 per cent. of cases, but the convalescence is prolonged, and at any time the disease may assume the characters of the acute variety and speedily prove fatal. The _differential diagnosis_ is often difficult, especially in the chronic nodules, in which it may be impossible to demonstrate the bacillus. The ulcerated lesions of farcy have to be distinguished from those of tubercle, syphilis, and other forms of infective granuloma. _Treatment._--Limited areas of disease should be completely excised. The general condition of the patient must be improved by tonics, good food, and favourable hygienic surroundings. In some cases potassium iodide acts beneficially. ACTINOMYCOSIS Actinomycosis is a chronic disease due to the action of an organism somewhat higher in the vegetable scale than ordinary bacteria--the _streptothrix actinomyces_ or _ray fungus_. [Illustration: FIG. 30.--Section of Actinomycosis Colony in Pus from Abscess of Liver, showing filaments and clubs of streptothrix actinomyces. × 400 diam. Gram's stain.] _Etiology and Morbid Anatomy._--The actinomyces, which has never been met with outside the body, gives rise in oxen, horses, and other animals to tumour-like masses composed of granulation tissue; and in man to chronic suppurative processes which may result in a condition resembling chronic pyæmia. The actinomyces is more complex in structure than other pathogenic organisms, and occurs in the tissues in the form of small, round, semi-translucent bodies, about the size of a pin-head or less, and consisting of colonies of the fungus. On account of their yellow tint they are spoken of as "sulphur grains." Each colony is made up of a series of thin, interlacing, and branching _filaments_, some of which are broken up so as to form masses or chains of _cocci_; and around the periphery of the colony are elongated, pear-shaped, hyaline, _club-like bodies_ (Fig. 30).