'288 APPLIED BACTERIOLOGY 



characteristic club-shaped structure. The periphery of the 

 swelling always feels hard, and a chronic fistulous opening 

 into the cavity may persist for months. The general 

 tendency of the disease is to spread continuously, the older 

 portions of the cavity sometimes showing a tendency to 

 form scar tissue, as in animals. There is rarely any pain, 

 fever, or constitutional symptoms. 



Bostrom considers the softening process an index to the 

 life and activity of the organism, and says that when a 

 centre is formed by granulation, the fungus is either 

 inactive or dead. 



The club forms are regarded by Bostrom as degeneration 

 forms of the terminal filaments of the fungus. Crookshank 

 says that each filament is enclosed in a sheath, and it is 

 owing to this undergoing mucilaginous degeneration that 

 the club forms are produced ; and if a little water is run 

 under the cover-glass, the club form disappears, leaving 

 the mycelium exposed to view. The active fungus appears 

 in the form of cocci arranged in chains or threads, which 

 freely interlace to form a network in the centre of the 

 colony. Bostrom has proved that these filaments are the 

 active portion, and could be cultivated on blood serum or 

 agar, while from the club-shaped portions he did not obtain 

 any growths. Crookshank has found that the organism is 

 more easily cultivated from man than from animals, and 

 that the most satisfactory medium is glycerine agar. After 

 repeated subculture the growths exhibit very peculiar forms. 

 The pathogenicity of the organism has been shown experi- 

 mentally by injecting a pure culture into the peritoneum 

 of rabbits and into the subcutaneous tissues of calves, and 

 in each case a typical actinomycosis has resulted. Kanthack 

 is of the opinion that ' madura disease ' (the ' fungus foot ' 

 of India) is produced by the same or a similar organism. 



