550 A MANUAL OF BACTERIOLOGY 



very different from that of the bovine variety, viz. tufts 

 of interlacing filaments stained by the gentian violet, but 

 a complete absence of purple clubs (Plate XXII, a). 

 Clubs, however, are frequently present around the peri- 

 phery of the filamentous tufts in a stunted condition, 

 although they do not usually stain by Gram's method. 

 These clubs are often seen better in fresh specimens of the 

 pus or in unstained sections, or by staining with orange- 

 rubin, or the Ehrlich-Biondi reagent (Plate XXII, 6). 

 The conditions in cattle and man, at first sight so very 

 different, are thus seen to present some similarity, which 

 is further established by the occasional occurrence in 

 cattle of filamentous tufts, staining by Gram's method, 

 within the rosettes, and by the clubs in man now and then 

 taking on the Gram stain. 



Actinomycosis in man in Europe is commonly caused 

 by the Cohnistreptothrix Israeli, occasionally by Nocardia 

 bovis. C. israeli is composed of short and long rods, 

 some of which show club-like swellings, while in old cul- 

 tures spores which resemble cocci in appearance can be 

 seen. It grows but poorly in the presence of air, but much 

 better anaerobically at 37 C. On agar it forms dew-like 

 drops, which later become yellowish and generally 

 remain discrete. In broth it forms a deposit of small 

 scaly particles. It does not grow on gelatin at room 

 temperature, but egg cultures show typical branched 

 filaments with clubbed ends, which later break up into 

 bacillary and coccal forms, but true arthrospores (i.e. 

 resistant spores) are not produced. It forms granula- 

 tion tumours when inoculated intraperitoneally into 

 rabbits and guinea-pigs, after an interval of four to seven 

 weeks. In these tumours typical actinomycotic grains 

 can be found, containing branched filaments with clavate 

 ends. The source of infection of man is not known with 

 certainty, though it is commonly supposed to be derived 



