SPOROTRICHEAE 787 



The type species is Aleurisma sporulosum Link. 

 This grenus was first described by Link as follows: 



18 Almorisma. Thallus e floccis raniosis, septatis, dcnsissime intertextis. Sporidia in- 

 spersa, minuta, glohosa. 



Thallus initium Boleti seu Poriae refert at sporidiis creberrimis immixtis genus declarat. 

 E floccis valde contextis, persistentihus constat, ita tit pcmnulwm fere sistat. Sporidia intra 

 thulium conglamerata. Unica species nondurrv descripta. 



Al. sporulosum, caespitibus indeterminatis crassis deusis albis. Caespitis ad 2-4 linneas 

 latos, ad lin. fere crassos format in ramis dejectis Nudo oculo massa/m farinosam continere 

 videtur. Et e Lusitania habemus. Iconem v. fig. 25. 



The figure does not help in the interpietation of the above, as it shows only flexuous 

 tangled nonseptate hyphae and a mass of unattached spores. 



Nees von Esenbeck, Bas System der Pilse und Schioomme 51, 1816, described Aleurisma 

 erubescens as new. 



Martius, Flora Cryptog. Erlungensis 335, 1817, described Aleurisma granulosum. as new. 



In 1818, Link reduced Aleurisma to Sporotrichutn and moved part of the original species 

 of Sporotrichum, to Alytosporium. 



In 183(5, Clievallier in Ins Flore gcncrale des environs d> Farts, ed. l', 1: 51, reestablished 

 Aleurisma, recognizing five species: A. erubescens, A. sporulosum, A. bulborum, A. saccharinum, 

 and A. flavissimiim. Of these, only A. sporulosum was described by Link when he first estab- 

 lished the genus and must be taken as the type. Other authors^ in general, ignored the work 

 of Chevallier until the genus was taken up by Vuillemin in 1911. A careful study of the 

 mechanism of spore development in A. fiavissimum led him to redefine the genus as recog- 

 nized at present. Vuillemin also reduced Blastomyces luteus Costantin & Eolland, the type 

 of Blastomyces, to synonymy with A. flavissirrmm. 



Hyphae repent, septate, branched ; aleurospores intermediate between 

 chlamydospores and true conidia, not provided with a well-developed mecha- 

 nism for spore discharge, but depending on the disintegration of the support- 

 ing cells in the mycelium ; spores unicellular, fairly thick-walled. 



Saprophytic, often on dung, very rarely parasitic. Some are inclined to 

 place the greater portion of the dermatophytes here, but it should be noted 

 that the mycelial cells are wholly uninucleate in Aleurisma Avhile they are 

 multinucleate in a relatively large portion of the life cycle in the dermato- 

 phytes. Very few of the pathogenic species referred here have been well 

 described, and still fewer have been carefully studied. It is possible that some 

 of the species reported as growing in the homy layer of the epidermis belong 

 in the dermatophytes. Aleurophora has also been referred here for want of 

 information to place it elsewhere. 



Key to Species 



Aleurospores elongate, coremia present. 



Colonies salmon color. A. salmoneum. 



Colonies white, elevated. A. dermatitidis. 



Colonies brown. A. albiciscans. 

 Aleurospores ovoid to spherical. 



From patclies of scaling witli slight pruritus. A. benigna. 



From vesico pustules. A. Ivgdunense. 



A. Vuillemvni. 



