VA RIE TIES OF A C TINOM YCES. 29 1 



masses is seen, and the medium becomes very slowly 

 liquefied. When this occurs the liquefied portion has a 

 brownish colour and somewhat syrupy consistence, and the 

 growths may be seen at the bottom, as little balls, from the 

 surface of which filaments radiate. 



In the cultures at an early stage the growth is composed 

 of branching filaments, which stain uniformly (Fig. 77), but 

 later some of the superficial filaments may show segmenta- 

 tion into gonidia. True clubs are not formed in cultures, 

 though slight bulbous thickenings may be seen at the end 

 of some of the filaments. 



Varieties of Actinomyces and Allied Forms. It is possible that in 

 the cases of the disease described in the human subject there may be 

 more than one variety or species of parasite belonging to the same 

 group. Gasperini has described several varieties of actinomyces bovis 

 according to the colour of the growths, and a similar condition may 

 obtain in the case of the human subject. Wolff and Israel cultivated 

 from two cases of " actinomycosis " in man a streptothrix which differs 

 in so many important points from the actinomyces that it is now 

 regarded as a distinct species. Eppinger also obtained from a brain 

 abscess another species of streptothrix, and there is also the strepto- 

 thrix madune presently to be described. 



In diseases of the lower animals several other forms have been 

 found. For example, a streptothrix has been shown by Nocard to be 

 the cause of a disease of the ox, "farcin du breuf," a disease in which 

 also there occur tumour-like masses of granulation tissue. The so- 

 called diphtheria of calves and " bacillary necrosis " in the ox are 

 probably both produced by another streptothrix which grows diffusely 

 in the tissues in the form of fine felted filaments. Further investiga- 

 tion may show that some of these or other species may occur in the 

 human subject in conditions which are not yet differentiated. 



Experimental Inoculation. Some observers (e.g., Bos- 

 trom) have obtained negative results by inoculation on 

 animals, but Israel and Wolff succeeded in the case of 

 guinea-pigs and rabbits. Intraperitoneal injection of the 

 parasite in the bacillary or filamentous form was followed 

 in a month by the production of nodules in the peritoneum 

 from the size of a pea to that of a plum. The nodules were 

 composed of granulation tissue, vascular on the surface, 

 and containing fatty pus in which colonies of typical 



