290 



ACT1NOMYCOSIS. 



condition are, however, not known, nor has the parasite 

 been cultivated from any source outside the body. 



Cultivation (for methods of isolation see later). The 

 actinomyces grows on a variety of media, though on all its 

 rate of growth is somewhat slow. Growth takes place at 

 the ordinary room temperature, but very slowly, the tem- 

 perature of the body being much more suitable. 



On agar or glycerine agar at 37 C., growth is generally 

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



transparent drops 

 which gradually en- 

 large and form 

 rounded projections 

 of a reddish -yellow 

 tint and somewhat 

 transparent appear- 

 - ; ance, like drops of 

 amber. The growths 

 tend to remain sepa- 

 rate, and even when 

 they become con- 

 fluent, the nodular 

 character is main- 

 tained. They have 



FlG. 77. Actinomyces, from a culture on H. tOUgh Consistence, 

 glycerine agar ; showing the branching of the being with difficulty 

 filaments. u i j j 



Stained with fuchsin. x 1000. 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 

 present the appearance of having been dusted with a 

 brownish -yellow powder (Fig. 76). The organism grows 

 well in the anaerobic condition on agar, and for this pur- 

 pose unopened eggs also, either in the fresh or boiled 

 condition, have been used, inoculation being effected by 

 drilling in the shell a small hole which is afterwards closed. 

 The growth on potatoes is somewhat similar to that on agar. 

 On gelatine the same tendency to grow in little spherical 



