312 MEDICAL MYCOLOGY 



sists of thick-walled, brown, spherical cells or two or three closely 

 associated cells. In its saprophytic phase on agar it is mvceloid 

 and grayish black. Sporulation occurs from lateral conidiophores, 

 which are phial-like or cup-like with funnel-shaped mouths. The 

 small spores are formed in the base of the cup and are extruded 

 but adhere in a spherical mass at the mouth of the cup. 



The natural habitat of P. verrucosa is revealed bv the work of 

 Conant (1937). He found that Cadophora americana, one of sev- 

 eral species that cause a blueing of wood pulp, is morphologically 

 and culturally identical with P. verrucosa. Further evidence of 

 their identity comes from their antigenic similarity, established by 

 Martin (1938). 



iVnother closely related species, Hormodendrwn pedrosoi, de- 

 scribed by Brumpt in 1922 [Brumpt (1935)], causes an involve- 

 ment whose clinical aspects cannot be distinguished from those 

 induced by P. verrucosa. This fact has been established by several 

 investigators, among whom are Emmons (1936) and Martin, 

 Baker, and Conant (1936). Further evidence adduced by Em- 

 mons and Carrion (1937) showed that some strains of H. pedrosoi 

 may form phialospores in culture. Not only have morphologic 

 relationships been established between these two fungi that pro- 

 duce chromoblastomycosis, but also serologic evidence of Martin, 

 Baker and Conant (1936) and Conant and Martin (1937) shows a 

 very close relationship. These workers found that H. pedrosoi 

 causes specific complement-fixing antibodies to form in the pa- 

 tients' serum and that there is a cross-antigenic relationship be- 

 tween strains of Hormodendrum and Phialophora. The taxono- 

 mic difficulties that have arisen in this complex are indicated by 

 combinations which have placed the pathogen in such genera as 

 Gomphinaria, Fonsecaea, Carrionia, Acrotheca, and Trichospor- 

 ium. Presumably one variable species only is involved in the pro- 

 duction of chromoblastomycosis, as is indicated in the brief but 

 comprehensive account by Carrion (1942). 



MALASSEZ1A OVALIS 



Approximately 75 years ago Malassez reported the occurrence 

 of an organism, Pityrosporimi ovale, in the squamae, follicles, and 

 sebaceous glands of the scalp. Since then many papers have been 

 published, interest in this organism being centered on its possible 



