ACHORION SCHOENLEINII. 163 



articulatis , ramosissimis, in stromate granuloso plerumque affixis t 

 anastomoticis. Receptaculum floods crassioribus e cellulis elon- 

 yatis formatum, subramosis, distincte articulatis, articulis incequali- 

 bus, irregularihus y in sporidio abeuntibus. Sporidia rotunda, ovalia, 

 vel irregularia, in uno vel pluribus lateribus germinantia. Species 

 Oidio affinis. (Remak.) 



Remak described the mycelium as articulated, which Robin 

 considers to be erroneous. Remak called also the tubes formed 

 by the spores mycelium, and supposed the tubes of the mycelium 

 anastomosed among themselves, whilst this takes place only with the 

 articulated filaments of the spores, according to Robin. Oidium 

 differs from Achorion in the tubular filaments which lie exposed, 

 and are not inclosed by an external thick and smooth layer. 



S pecies Achorion Schoenleinii. 



Synonyms : Oidii species, Oidium Schoenleinii, Mycoderme de la 

 teigne, Cryptogame de la teigne faveuse. Champignon de la teigne 

 scrophuleuse, faveuse, Fungus Porriginis. 



Signa generis. 



Habitat : In cute capitis humani, etiam in aliis corporis regioni- 

 bus, et in folliculis papillorum inque depressionibus superficiei cutis ; 

 porro in unguibus digitorum manus et pedis. 



It had been overlooked, until Robin and Bazin pointed it out, 

 that this parasite attaches itself to the bottom of the hair-follicle 

 in the direction of the hair, more commonly, however, to the 

 simple layer of the cells of the epidermis. Here spores only, or 

 closely articulated filaments, are met with. These spores adhere 

 for the most part to the hair, and create on its surface circular 

 enveloping masses, which spread out more or less, and form a kind 

 of sheath for it. Sometimes the spores occur close together, 

 sometimes forming single, double, or treble rows, which are con- 

 nected by means of smaller rows, and form a kind of network, 

 which adheres firmly to the hair, and often appears discoloured on 

 account of the copious layer of spores. Sometimes the spores 

 penetrate into the root of the hair, which becomes then disfigured, 

 dried up, and fibrous, even in the interspaces between the fibrillae. 

 Spores are likewise found at that part of the hair which lies free, 

 outside the follicle, on the angles formed by the hair in its folds, 

 &c. The hair-follicle is changed, moreover, as well as the bulb 

 of the hair, and it becomes atrophied and thin. The penetrating 

 of the spores into the follicle explains the pertinacity of favus. 



If the parasite be found accumulated in the depressions of the.. 



