ACTINOMYCOSIS 



2143 



non-granular and not eosinophile, this cell agrees with Unna's 

 description of a healthy plasma cell as seen in actinomycosis. 



A third type of cell shows a large vesicular nucleus situate 

 excentrically in a relatively large quantity of cytoplasm, which is 

 either eosinophile or contains eosinophile granules, and corresponds 

 exactly with Unna's description of degenerating plasma cells as seen 

 in actinomycosis. 



Fungal Masses. — -The darker irregular bodies seen embedded in 

 the matrix, if examined by the aid of higher magnification, can be 

 seen to consist of fibrous tissue and cells surrounding a portion 

 of the fungus, and have, therefore, for purposes of distinction, been 

 termed * fungal masses.' 



When a typical fungal mass is examined by means of a moder- 

 ately high magnification, it can be seen to be composed of several 

 distinct areas, which, working from the fibrous tissue matrix 

 towards the fungus, lie in the following order : — 



1. The Fibrous Sheath. — ^This is continuous with the fibrous 

 tissue forming the matrix of the whole growth, as already described. 



2. The Fibrocellular Layers. — Directly under the dense fibrous 

 tissue there lies a thicker or thinner area composed of loose fibrous 

 tissue, containing in its meshes cells and thin-walled vessels; this 

 area may be termed the fibrocellular layers. 



3. The Cellular Sheath. — Internal to the fibrocellular layers comes 

 a mass of cells which may be called the cellular sheath. 



Fig. 848. — Actinomycosis. 



