294 



ACTINOMYCOSIS AND ALLIED DISEASES. 



exposed to infection from this source. The position of the 

 lesions in cattle is also in favour of such a view. 



Cultivation (for methods of 

 isolation see later). The actino- 

 myces grows on a variety of 

 media, though on all its rate 

 of growth is somewhat slow. 

 Growth takes place at the ordi- 

 nary room temperature, but very 

 slowly, the temperature of the 

 body being much more suitable, 

 and it would seem that an ana- 

 erobic condition is more produc- 

 tive of positive results in many 

 instances than where oxygen is 

 not excluded. 



On agar or glycerin agar at 

 37 C, growth is generally visi- 

 ble on the third or fourth day in 

 the form of little transparent 

 FiG.io 4 .-Cuituresoftheactinomyceson drops which gradually enlarge 



glycerin agar, of about three weeks' growth, and f orm roun ded projections of 

 showing the appearances which occur. 



The growth in A is at places somewhat a reddish-yellow tint and some- 



corrugated on the surface. Natural size. what transpare nt appearance, 



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

 even when they become con- 

 fluent, the nodular character 

 is maintained. They have a 

 tough consistence, being with 

 difficulty 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 appear- 

 ance of having been dusted 

 with a brownish-yellow powder 

 (Fig. 104). The organism 

 grows well in the anaerobic 



Condition On agar, and for this filaments. Stained with fuchsin. 



