MICROSPORON FURFUR. 159 



has never been found to occur previous to puberty, but' always 

 after the individual had reached from the fourteenth to the six- 

 teenth year, and it seems more especially to attack such persons 

 as are suffering from tuberculosis. 



Eichstadt discovered the fungus in 1846, and after him, in 1847, 

 much attention was paid to it by Sluyter ; Robin himself did not 

 find it; H. E. Richter describes it as Mycoderma Eichstadtii. 



Gudden has occupied himself much with this disease lately 

 without determining the nature of the fungus. The fungus 

 establishes itself on the skin of both the healthy and the sick, 

 especially amongst the poorer people. It is found, however, also 

 on the most luxuriously clean and rich ; more rarely on women 

 than on men, never on children. It spreads mostly over the back 

 and even the whole of the chest. It ascends often along the 

 neck and attacks the extremities. Its horror of such parts of 

 the body as are kept constantly bare is so great that Gudden saw 

 a young man who went with his chest uncovered, arid who was 

 attacked all around by the fungus whilst the open space was left 

 quite free and uninjured. These brown spots, called chloasmata, 

 rise rarely above the level of the skin, and the finger experiences 

 a rough sensation when passed over them. The surface, which 

 is at first smooth, peels off after a little while. The disease con- 

 centrates itself, at first around small spots, which are seen, with a 

 few exceptions, pierced by a little hair. 



Means of discovering the fungus. A vesicator should be placed 

 on the diseased spot, and the vesicle removed as soon as possible and 

 spread upon a glass plate suspended over a dark surface, and the 

 soft serum removed from its lower surface by means of a fine pair 

 of pincers, which is easily done with a little care. Nothing re- 

 mains but the upper, thin, transparent, and firm layer, and its 

 continuation on the sheath of the hair, so that the fungus is very 

 well seen through it, as well as an innumerable quantity of small 

 dots which appear to be whitish under reflected light, and darker 

 by transmitted light. They are the openings of the perspiriferous 

 glands, consisting of epidermal cells closely and flatly pressed 

 one against the other, and which stand erect, are well developed, 

 and contain a yellow pigment. These glands are very constant, 

 and remain intact in the midst of the fungi. They are sur- 

 rounded by spores, and present then darker, yellow-brownish, 

 and funnel-shaped cavities. The fungus does not penetrate into 

 the cavities of the pores themselves. The cells of the epidermis are 



