158 VEGETABLE PAEASITES. 



VI. Microsporon furfur = Fungus seu Epiphytes Pityriasis 

 versicoloris. (Tab. Ill, figs. 1 4.) 



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Trichomata (fila) in squamis epithelialibus sit a, nunquam etiam 

 earum marginem excedentia, multipliciter torta et inter se nexa y ut 

 raro finis fill cvjusdam certo cognosci queat ; simplicibus, parallehs 

 lineis terminata, nunquam aut articulata aut in margine vincta, nee 

 contenti quid in eo apparet ; passim in ramulos divisa. Sporidia 

 rotunda binis adumbrantur lineis concentricis, quarum interior 

 spatium lucidum circumdat ; in acervulis agminata. 



Habitat. In cute hominis cegroti. 



Ab aliis speciebus generis differt longitudine trichomatorum ac 

 ramulorum et forma sporidiorum semper rotunda. 



The parasite consists partly of elongated and branched cells 

 (fila, filamenta, trichomata), partly of spores which are piled up in 

 groups or in heaps, some of these being 100 mm. in diameter. 

 They refract the light strongly, and appear, like all bodies which 

 do the same, to be limited by two concentric lines, which are 

 again bounded by a fine, bright space, which is, however, darker 

 than the brilliant centre of the spore. Caustic ammonia added 

 to the crusts or scales of the diseased skin renders the parasite 

 more distinctly visible. Its seat is more particularly the skin of 

 the breast and stomach, sometimes also that of the extremities, 

 never that of parts which are exposed to the air. It grows 

 rapidly, though the nature of the growth of the spores is yet 

 unknown. 



The appearance of this fungus is ushered in by the formation 

 of more or less yellowish or yellow-brownish spots, which are con- 

 stantly scaling off and itching, never rising above the level of the 

 skin, and which are of various sizes and pulverulent on the 

 surface. The whole forms the "Pityriasis versicolor. )} These 

 small spots are at first of the size of a pea, they increase, how- 

 ever, gradually and rise together, spreading to the breadth of two 

 hands and uninterruptedly from the thorax to the body. The 

 itching is increased by hard work and spirituous liquors. 



Sluyter and Eichstadt have clearly proved that lying in a bed 

 which was formerly occupied by any one suffering from " Pityriasis 

 versicolor " will communicate it, and they doubt not that this 

 disease is caused by the parasite. The evil is purely local ; it 



