148 VEGETABLE PAEASITES. 



fibres, which gives at last to the hair the appearance of a brush 

 or of a hedgehog's skin in the opening of the hair in some 

 places, through which the spores pass, in the condensation of the 

 hair epithelium, the disappearance of many of the cylinders of 

 hair, and the adhesion of tufts o hair by means of new forma- 

 tions. 



The peculiar adhesive mass consists of a great many large 

 epithelial cells, w r ith many small granular bodies resembling the 

 exudation corpuscles of inflammation, of thinned hair whose 

 sheath is covered with spores, in some places of a few epithelial 

 cells, often of the " Glandules sebacea" and of the parasite which 

 rarely rises above this sheath. The mass is brownish, adhesive, 

 soft, and binds the hair together in bundles, sometimes it dries 

 up in some places, and becomes then of various shapes and sizes. 

 Hebra and Wedl have made similar observations, though they 

 never found spores in the interior of the hair-canals, but masses 

 of parasitical plants on and between the plicated hair. Every- 

 where on the adherent mass there could be discerned round spores, 

 with a distinct nucleus measuring 003 7 mil. in diameter. 

 They formed groups on the periphery of the hair, and nestled in 

 the spindle-like split-up cells of the hair. Very rarely the 

 thallus-filaments are found in the shape of square cells placed in 

 a line. The hair itself was brittle and split up. 



Von Walther's experiments on inoculation of the plica polonica 

 were unsuccessful ; Beschorner, however, thinks he succeeded. 



lib. Species Trichophyton sporuloides. 



Von Walther, of Kiew, Russia, stated in 1844 that he had 

 found, in a case of plica polonica, by means of the microscope, 

 a hoar-frost-like covering on all the hairs, which seemed partly to 

 scale off, as well as dirt, insects, epidermal scales, feathers, espe- 

 cially linen threads from the plicated spots, together with small 

 shriveled-up globules on the hair, and other accidental impurities. 

 Skoda also saw many lice in it, and Von Hessling three mites 

 which were not yet known, which, however, he does not think 

 are peculiar to plica polonica (see Acari in Animal Parasites). 



When the quite fresh soft mass from the plica polonica was 

 examined in which healthy hairs were left, it was found to be no 



