1893.] Existence of more than one Fungus in Mycetoma. Ill 



examination of seven specimens of the black variety and of eighteen 

 of the white, obtained from Bombay and from the various museums 

 throughout the United Kingdom. 



Black Variety. — Sections of the particles, free or in situ in the 

 tissues, show that they are composed of tufts of a deep brown colour, 

 and apart from a faint radiation or the presence of a slight venation 

 or of holes, they give very little indication of a vegetable structure. 

 By boiling the particles for from a few minutes to one hour in concen- 

 trated caustic potash, the brown colouring matter is very slightly 

 removed, but this is completely discharged upon transferring them to 

 distilled water ; the fungus can then be readily studied. The animal 

 tissues are however, destroyed by this process. If, however, the 

 tissue containing the particles is embedded in collodion, washed for 

 about one minute in " eau de Javel" and then stained, the colouring 

 matter is removed from the fungus, and its relationship to the tissues 

 around can be readily seen. The fungus appears the same in all the 

 specimens of the black ; the hyphse radiate and branch, the segments 

 vary very greatly in size ; they may be spherical and reach a very 

 great size, or long and slender ; a pseudo-parenchyma may be formed 

 in the centre of a tuft, or a palisade at the periphery. We have seen 

 no organs of fructification. Tissue reaction. — The tufts are embedded 

 in granulation tissue or necrosed material, and the presence of very 

 large giant cells and other phagocytes is characteristic. The hyphas 

 may penetrate the vessels and run in their anterior. The metamorphosis 

 of the fungus appears to take place very early and affects equally 

 the various hyphee throughout the tissues. The nature and meaning 

 of the change is very obscure. The dried particles burn with a 

 luminous flame. Incinerated, there is a slight smell of burnt feathers, 

 and in the ash, which is very little, there is a brown coloration, owing 

 to the presence oi iron ; the presence of the latter may be confirmed 

 in the unclarified and clarified specimens by the Prussian blue test. 

 The iron is, however, limited to the periphery of the tufts, and appears 

 wholly derived from the animal tissues. The particles give a red 

 reaction with dilute nitric and hydrochloric acids : little impression 

 is produced upon them by boiling in the various fat solvents ; they 

 give no special reactions with ferric chloride or cupric acetate (resin 

 test). 



White Variety. — Sections of the particles are characteristic. In the 

 centre are usually numerous small reniform deeply- staining masses, 

 surrounded by a deep radiate zone. In the central bodies a very fine 

 reticulum may occasionally be made out ; more usually, stronger 

 evidence of the fungus is obtained by the presence of dwarfed club- 

 like hyphae, which form an irregular fringe to the reniform bodies. 

 It is exceedingly difficult to ascertain what gives rise to the deep 

 radiate zone; the leucocytes in it are compressed, yet the compressing 



