NON-SPOBING BACILLI 287 



Description. An anaerobe of slow growth, growing best 

 at 37 C. ; and in a shake culture in glucose agar, the 

 colonies are most numerous 5 to 10 mm. below the surface 

 of the medium, the inference being that a trace of oxygen 

 is an advantage. The colonies are round, dense, and 

 greyish-white in colour (chalky) ; sometimes they are 

 rosette-shaped. Another variety has been described which 

 is an aerobe, growing in three to four days to little 

 transparent drops, becoming later amber, and then reddish- 

 yellow in colour. This variety has been grown on gelatin, 

 which it liquefies. In cultures, club-shaped forms have 

 not been found in the aerobic variety, but have been noted 

 by J. H. Wright in the anaerobic variety when grown in 

 the presence of serum or other animal fluids. It is believed 

 that several kinds have been described under the one 

 name, and that further research is needed to differentiate 

 these. The anaerobic form grows in broth, forming heavy 

 flocculent masses (solid white mulberry granules) at the 

 bottom of the tube ; no clouding nor surface growth. 



The fungus is described as having three forms : 

 (i) Filaments, more or less radially arranged, 0-5 micron 

 thick, and closely interlaced. These form the central core 

 of the colony. (2) At the periphery, refringent club-shaped 

 bodies, structureless and homogeneous ; whereas the 

 filaments show a sheath, enclosing a granular protoplasm. 

 (3) Spores or gonidia are coccus-like bodies, found between 

 the filaments of the central mass ; are variously regarded 

 as real gonidia, or as degeneration products, or con- 

 taminating cocci. In cultures, gonidia are developed at 

 the ends of the filaments, and such gonidia have a higher 

 resistance to heat than the simple filaments, half an hour 

 at 75 C. being required to kill spore-bearing cultures, and 

 the same time at 65 C. for spore-free cultures. The 

 filaments are Gram-positive and acid-fast. 



Pathogenicity. In man, the disease tends to generalize ; 

 in the ox, to remain local. The point of entrance in man 

 is usually by a carious tooth, by the tonsil, or by some 

 abrasion. The corresponding glands are next affected, 

 and later metastatic abscesses are formed in the skin and 

 elsewhere. The symptoms resemble those of chronic 

 tuberculosis, for which the patient is usually treated. The 



