TRICHOPHYTON PLICAE POLONICyE. 147 





II#. Species Trichophyton = Trychomaphytes = Mycoderma 

 (Giinsburg) Plicae polonica. (Tab. II, B, figs. 36.) 



After Giinsburg had, in 1843, found a plant in the medullary 

 channel of the hair of a person suffering from the plica polonica 

 Johann Miiller, and afterwards Miinter, Baum, Simon, Hessling, 

 Skoda, and Fr. Miiller, who could not again find the fungus, 

 were of opinion that the discovery had been accidental. 



Hebra saw, in one case, as Wedl tells us, on and between 

 the hair of a queue, an immense number of these parasites; but 

 he also, like most modern writers, thinks that the fungus is no 

 pathognomonic sign of this disease, but a mere accidental com- 

 pagnon of it ; and he places the discovered fungus accordingly 

 with those of Walther, which will be described hereafter. 



Giinsburg seems to entertain still the same view with regard 

 to this fungus. He says in a letter that the fungi are found 

 between the root and the hair, in the marrow of the hair, and 

 underneath the epithelial covering of the hair, which causes them 

 to swell and to split. 



It is clear from a comparison of Malmsteu's parasites and 

 those of Giinsburg, that the nature of their growth, and, more- 

 over, the effect on the hair itself, is quite different in the two 

 species, and we can therefore see no reason why they should 

 be made one. 



The parasite itself forms (according to Giinsburg) articulated 

 filaments, though rarely occurring, and showing no inter-cellular 

 spaces in its interior. The spores are very numerous, round or 

 oval, with a smooth surface sometimes articulated by umbilical 

 spots. The cells are for the most part isolated, sometimes 

 grouped together, and sometimes fastened to a very fine fibrous 

 hypothallus. Iodine dissolves its structure completely, vinegar 

 and caustic potash (kali causticum) do not alter it. The spores 

 measure 0*002 5 mm., and contain point-like molecular gra- 

 nules, and rarely distinct nuclei. 



The changes in the hair produced by this parasite consist, 

 according to Giinsburg, in the thickening of the root of the hair, 

 a spindle-like enlargement of the longitudinal cylinder of the 

 channel of the hair, through the constant piling up of new 

 masses of fungi in it, in the splitting and parting of single hair 



