DESCRIPTION OF PLATE IX. 



FIG. i. Tuberculous pleurisy. Wet preparation stained with 

 methylene blue, showing lymphocytes and red corpuscles. 

 (The nucleoli are not usually so clearly shown, and are not 

 seen in dried films without special staining-.) 



FIG. 2. Pus from knee affected with gonococcal arthritis 

 (early in the disease). The figure will serve to show the 

 appearances in an early case of septic pleurisy or empyema. 

 Polynuclear cells predominate, but there are a few lympho- 

 cytes. The large cells are endothelial, and have ingested 

 some polynuclear leucocytes which show fragmentation of 

 the nucleus. Film dried, fixed with perchloride of mercury, 

 and stained with carbol thionin. 



FIG. 3. Pus from an old pneumococcic empyema. The cells 

 are polynuclears, but are highly degenerated, and stain 

 very feebly. Stained as in Fig. 2. (All magnified 1000 

 diameters.) 



