CULTIVATION OF ACTINOMYCES 



293 



visible on the third or fourth day in the form of little transparent 

 drops which gradually enlarge and form rounded projections of 

 a reddish-yellow tint and somewhat transparent appearance, like 

 drops of amber. The growths tend to remain separate, and even 

 when they become confluent, the nodular character is maintained. 

 They have a tough con- 

 sistence, being with diffi- 

 culty broken up, and ad- 

 here firmly to the surface 

 of the agar. Older growths 

 often show on the surface 

 a sort of corrugated aspect, 

 and may sometimes pre- 

 sent the appearance of 

 having been dusted with 

 a brownish-yellow powder 

 (Fig. 99). ' 



In the cultures at an 

 early stage the growth is 

 composed of branching 

 filaments, which stain 

 uniformly (Fig. 100), but 

 later some of the super- 

 ficial filaments may show 

 segmentation into gonidia. 

 Slight bulbous thicken- 

 ings may be seen at the 

 end of some of the fila- 

 ments, but true clubs 

 have not been observed. A B 



On gelatin the same FIG. 99. Cultures of the actinomyces on 

 tendency to grow in little glycerin agar, of about three weeks' growth, 

 SDherical masses is seen showing the appearances which occur. The 



, growth in A is at places somewhat corru- 



and the medium becomes gated on the sllrface . Natural size. 

 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. 



The organism obtained in culture by Wolff and Israel (vide 

 infra) is probably the same as the one which has been recently 

 described in detail by J. H. Wright, who obtained it in pure con- 

 dition from fifteen different cases of the disease. It differs markedly 

 from Bostrom's organism in being almost a strict anaerobe and in 



