HORMODENDR UM 



1097 



Remarks. — This family contains the genera Hormodendrum 

 Bonorden, 1851, and Malassezia Baillon, 1889, which are recogniz- 

 able as follows : — 



All sterile hyphae creeping. Conidia all alike and produced on the hyphae. 

 Conidiophores not spirally twisted; hyphae dendroid: — 



A. Gonidia in cultures in chains, in parasitic form in masses — Genus 



Hormodendrum Bonorden, 1851. 



B. Conidia in parasitic form in masses. Cultural form unknown — 



Genus Malassezia Baillon, 1889. 



Genus Hormodendrum Bonorden, 1851. 



Definition. — Haplographiaceae with creeping dendroid sterile 

 hyphae and branched conidiophores, bearing conidia all of one kind. 



Remarks. — ^The genus Hormodendrum contains about ten 

 species, which are generally parasitic on plants or saprophytic, but 

 one is known to occur in man— viz., H. fontoynonti. 



Type Species. — Hormodendrum olivaceum (Corda, 1838). The 

 name is derived from op/jLo^, 'a chain,' and 8€u8po<i (or ShSpov), 'a. 

 tree.' 



Hormodendrum fontoynonti Langeron, 1913. 



Definition. — -Hormodendrum in cultures with sterile hyphse 3 to 

 8 microns in diameter, greenish brown in colour, septate with thick 

 walls. Sporophores well defined, not swollen at the extremity, 

 carrying chains of very caducous spores. In man mycelium broken 

 in segments, long and undulating; spores, which are capable of 

 budding, arranged in masses. 



Remarks.— Found by Fontoynont and Carougeau in the scales of 

 a dermatosis, called ' hodi-potsy ' in Madagascar, which is comparable 

 to that termed ' tinea flava ' in other tropical countries. It is 

 doubtful whether the fungus is the setiological agent of the 

 condition. 



Genus Malassezia Baillon, 1889. 



Definition.— In man mycelium broken into septate segments, 

 with T-shaped or budding extremities. The hyphae carry round or 

 oval conidia, which may be solitary or in grape-like masses, and 

 may be smooth or with longitudinal, radial, or spiral marks. In 

 culture unknown. 



Remarks.— This genus is only known to contain parasites of man. 

 The two species may be recognized as follows : — ■ 



I. Causing a brown eruption on the white skin — i.e., tinea 

 versicolor. Lesions very superficial— Species Malas- 

 sezia furfur Charles Robin, 1853. 

 II. Causing a red eruption on the white skin and a yellow erup- 

 tion on the dark skin — 4.e., tinea flava. Deeper lesions — ■ 

 Species Malassezia tropica (Castellani, 1905). 



