SYSTEMATIC AND DESCRIPTIVE. 337 



dothrix group, and possibly closely allied to the 

 Streptothrix Fcersteri of Cohn. 



METHODS OF EXAMINING AND STAINING 

 ACTINOMYCES 



In the fresh state a little of the tissue of a tumour, or the 

 purulent detritus, may be transferred to a clean glass slide, 

 and teased out with needles. The little specks are easily 

 recognised, and can be isolated with the needles and 

 transferred to a drop of glycerine upon a fresh slide. A 

 cover-glass must then be gently pressed down upon the 

 preparation, which is then examined. To stain the fresh 

 tufts, the little fungus masses are teased out, and transferred 

 to a watch-glass containing alcohol, to which a few drops of 

 concentrated alcoholic solution of eosin are added. They 

 can be mounted and preserved in glycerine. 



Sections can be stained by either of the following 

 methods. 



Weigerfs Methcd : 



Immerse the sections for one hour in orseille, rinse with 

 alcohol, and after-stain with gentian violet (Plate XXVIIL). 



Platris Method: 



Sections are left for ten minutes in Gibbes' solution (No. 

 22), warmed to 45 C. They are then rinsed in water, and 

 after-stained in concentrated alcoholic solution of picric 

 acid for five to ten minutes ; immersed in water five minutes, 

 50 per cent, alcohol fifteen minutes, passed through absolute 

 alcohol and clove-oil, and preserved in Canada balsam 

 (Plate XXVI I.). 



22 



