On Dematium pullulans de Bary. Isme A. Hoggan. 103 



asserts that fragments of sporophores of Cladosporiiim when 

 placed in water also gave origin to the Dematium fomi of repro- 

 duction. It must be confessed, however, that this account 

 suggests itself to the \mter as one based upon a mistaken identity, 

 in which the broNMi cells ascribed to Cladosporinm were in 

 reahtv the superficially similar gemmae or resting mycelium 

 of Dematium. The latter fungus, being particularly abundant 

 on the surface of plants, would be a probable contamination 

 in these circumstances, and in the resting condition would be 

 distinguished onlv \\ith difficulty from the mycelium of Clado- 

 sporium. 



Other \mters s, 9, 10) assert the identity of the two forms 

 without adducing further proof. 



On the other hand, Schostakowitschui) never found any 

 trace of Dematium in cultures of Cladosporium or Hormodendron, 

 though these were grown under varpng conditions, neither did 

 he obtain the reverse effect. Nor was Berleser::) any more 

 successful, and this author suggests that the discrepancy in 

 the results of other investigators is due to contamination of the 

 source of supply of the spores. He does not, however, deny the 

 possibility of such relationship. 



Planchon {loc. cit.) failed equally to estabhsh any connection 

 between the two forms, and, more recently F. T. Brooks (13), 

 in a svstematic study of numerous strains of Cladosporium 

 isolated from "black spot" of meat and from other sources, 

 found no indication of any connection of this fungus \nth 

 Dematium pullulans. 



The ^Titer's own observations point to the same conclusion. 

 Cultures of several strains of Dematium pullulans have been 

 studied for some months on various artificial media without 

 disclosing any trace of associated Cladosporium. 



To siun up, the e\idence which has been brought forward as 

 indicating a genetic relationship between the two fungi is 

 dismissed; the existence of such a relationship is denied. 



(b) Relationships with Ascomycetous Fungi. 



Turning now to another class of fungi, we find certain forms 

 among the P\Tenomycetes which possess a stage in the hfe-cycle 

 so closelv resembling Dematium pullulans as to suggest some- 

 thing more than a mere superficial resemblance between the two. 



Such a fungus is Plourightia ribesia Sacc. According to 

 Brefeldii-t) the ascospores of this fungus give rise in culture to 

 an abundant mycehum which rapidly develops oval conidia 

 and which presents an appearance strikingly similar to a t\*pical 

 growth of Dematium. Moreover the conidia may bud in a yeast- 

 like manner, and, on exhaustion of the medium, gemma-forma- 



