Actinomyces may be cultivated, like other parasitic diseases, outside the body. Gelatine, blood serum, agar, glycerine agar, and potato have been used for this purpose. After a few days on glycerine agar at the temperature of the blood little white shining colonies appear, which increase and coalesce. In about ten days' time the culture often turns a bright yellow, though it may remain white or even take on a brown or olive tint. The entire mass of growth is raised dry and crinkled, and composed almost exclusively of threads. In its early stage small bacillary forms occur, and in its later stage coccal forms. True clubs never occur in pure cultures, although the threads may occasionally show bulbous endings.
+Glanders+ in the horse and ass, and sometimes by communication in man also, is caused by a short, non-motile, aërobic bacillus, named, after the old Roman nomenclature (_malleus_), _Bacillus mallei_. It was discovered in 1882 by Löffler and Schütz. It is found in the nasal discharge of glandered animals. In appearance the bacillus is not unlike _B. tuberculosis_, except that it is shorter and thicker. The beading of the bacillus of glanders, like that in tubercle, does not denote spores. _B. mallei_ can be cultivated on the usual media, especially on glycerine agar and potato. On the latter medium it forms a very characteristic honey-like growth, which later becomes reddish-brown.
In the horse glanders particularly affects the nasal mucous membrane, forming nodules which degenerate and emit an offensive discharge. From the nose, or nasal septum, as a centre, the disease spreads to surrounding parts. It may also occur as nodules in and under the skin, when it is known as "farcy." Persons attending a glandered animal may contract the disease, often by direct inoculation.
_Mallein_ is a substance analogous to tuberculin, and is made by growing a pure culture of _Bacillus mallei_ in glycerine-veal broth in flat flasks, with free access of calcined air. After a month's growth the culture is sterilised, filtered, concentrated, and mixed with an equal volume of a .5 per cent. solution of carbolic. The dose is 1 cc., and it is used, like tuberculin, for diagnostic purposes. If the suspected animal reacts to the injection, it is suffering from glanders. Reaction is judged by three signs, namely, a rise of temperature 2-3° C., a large "soup-plate" swelling at the site of inoculation, and an enlargement of the lymphatic glands.