Sporulation of the Phialophora Type in Hormodendrum

Hormodendrum is an important genus of the Fungi Imperfecti. Its species have a wide geographical distribution and are commonly present in soil and decaying vegetation. Because of the ubiquity of its wind-blown spores it is a familiar culture weed of the laboratory. M/ost species of the genus are saprophytes, but at least two are facultative pathogens of man and there cause a skin disease known as dermatitis (chromoblastomycosis). This disease apparently is not contagious, and the evidence at hand indicates that the fungus is a wound parasite capable of growing in animal tissue only after its introduction upon some foreign body such as a thorn. In this respect it is like some of the other mycotic diseases in which the parasitic agent requires certain special, and in some cases, unknown conditions before it becomes pathogenic, but once established in the human body, it is extremely difficult to dislodge. Dermatitis verrucosa occurs chiefly in the tropics, and more rarely in temperate climates. Three cases have been reported from the United States. The disease is generally characterized in man by the formation on an extremity, usually a leg, of warty or cauliflower-like outgrowths of the skin (FIG. 1). In some cases it has been possible to obtain from the patient a history of some slight injury to the foot, followed by the slow appearance and development of a small initial lesion. By slow extension of this primary lesion the entire lower leg may become involved. Extension of the pathologic process is not rapid, and a duration of several years, without metastatic spread, and without serious interference with the activities of the patient is the rule. Sections of the infected tissue show the fungus present in the form of subspherical pigmented cells often occurring in pairs or short chains. In spite of