734 Actinomycosis 



upon gelatinization of the cell-membrane of the degenerating para- 

 site. The club is one of the chief characteristics of the organism. 

 In sections of tissue the radiating filaments are very distinct, and 

 the terminal clubs are all directed outward, closely packed together, 

 and making the whole mass form a rounded little body often spoken 

 of as an "actinomyces grain." When tissues are stained first with 

 carmin and then by Gram's method, the fungous threads appear 

 blue-black, the clubs red. The cells of the tissues affected and a 

 larger or smaller collection of leukocytes form the surrounding re- 

 sisting tissue-zone. 



The fungus is of sufficient size to be detected in pus, etc., by the 

 naked eye. As it usually has a bright yellow color it is not in- 

 frequently spoken of as a "sulphur grain." 



Fig. 300. — Actinomyces granule crushed beneath a cover-glass, showing radial 

 striations in the hyaline masses. Preparation not stained; low magnifying 

 power (Wright and Brown). 



Cultivation. — The actinomyces fungus may be grown upon arti- 

 ficial culture media, as has been shown by Israel,* Wolff, and 

 others. 



"The granules, preferably obtained from closed lesions, are first 

 thoroughly washed in sterile water or bouillon and then crushed and 

 disintegrated between two sterile slides. If one is working with a 

 bovine case it is well to examine microscopically the disintegrated 

 material, after mixing it with a drop or two of bouillon under a cover- 

 glass, to see if filamentous masses are present. If they are not, or 

 if they are very few, proceed no further, but begin again with another 

 granule, because the granules in bovine lesions sometimes contain 

 no living filaments at all, but may be composed entirely of de- 

 generated structures from which no growth of micro-organisms can be 

 * "Virchow's Archives," cxv. 



