298 ACTINOMYCOSIS AND ALLIED DISEASES 



formation of fistulous openings and ulcers. There are great en- 

 largement and distortion of the part and frequently caries and 

 necrosis of the bones. Within the softened cavities and also in 

 the spaces between the fibrous tissue, small rounded bodies or 

 granules, bearing a certain resemblance to the actinomyces, are 

 present. These may have a yellowish or pinkish colour, com- 

 pared from their appearance to fish roe, or they may be black 

 like grains of gunpowder, and may by their conglomeration 

 form nodules of considerable size. Hence a pale variety and 

 a black variety of the disease have been distinguished ; in both 

 varieties the granules mentioned reach a rather larger size 



than in actinomycosis. 

 These two conditions will 

 be considered separately. 

 Pale Variety. When 

 the roe-like granules are 

 examined microscopic- 

 ally, they are found, like 

 the actinomyces, to show 

 in their interior an abun- 

 dant mass of branching 

 filaments with mycelial 

 arrangement. There may 

 also be present at the 

 periphery club-like struc- 

 tures, as in actinomyces ; 

 sometimes they are ab- 

 sent. These structures 

 often have an elongated 



agar. Stained with carbol-thionin-blue. wedge-shape, iorming an 

 x 1000. outer zone to the colony, 



and in some cases the 



filaments can be found to be connected with them. Vincent 

 obtained cultures of the parasite from a case in Algiers, and found 

 it to be a distinct species : it is now known as the streptothrix 

 Madurce. Morphologically it closely resembles the actinomyces, 

 but it presents certain differences in cultural characters. In 

 gelatin it forms raised colonies of a yellowish colour, with 

 umbilication of the centre, and there is no liquefaction of the 

 medium. On agar the growth assumes a reddish colour ; the 

 organism flourishes well in various vegetable infusions in which 

 the actinomyces does not grow. On all the media growth only 

 takes place in aerobic conditions. Experimental inoculation of 

 various animals has failed to reproduce the disease. There is 



