966 



THE HIGHER BACTERIA, MOLDS AND FUNGI 



to the disease was first observed by Bellinger 19 in 1877. In the 

 following year Israel 20 discovered a similar microorganism in human 

 cases. 



The parasites appear in the pus from discharging lesions as small 

 granular bodies, plainly visible to the naked eye and somewhat 

 resembling sulphur granules, of a grayish or of a pale yellow color. 

 In size they measure usually a frac- 

 tion of a millimeter. Ordinarily they 

 are soft and easily crushed under a 

 cover-slip, but occasionally, especially in 

 old lesions, they may be quite hard, 

 owing to calcification. 



FIG. 103. ACTINOMYCES GRANULE CRUSHED 

 BENEATH A COVER-GLASS. Unstained. 

 Low power. Shows radial striations. (After 

 Wright and Brown.) 



FIG. 104. ACTINOMYCES 

 GRANULE CRUSHED BE- 

 NEATH A COVER-GLASS. 

 Unstained. The prepara- 

 tion shows the margin of the 

 granule and the "clubs." 

 (After Wright and Brown) . 



Microscopically they are most easily recognized in fresh prepara- 

 tions prepared by crushing the granules upon the slide under a 

 cover-slip and examining them without staining. They may be 

 rendered more clearly visible by the addition of a drop or two of 

 20 per cent potassium hydrate. When the granules are calcareous, 

 the addition of a drop of concentrated acetic acid will facilitate 



Bollinger, Deutsch. Zeit. f. Thiermed., iii, 1877. 



20 Israel, Virch. Arch., 74, 1878 and 1879, LXXVIII, 421. 



