i 4 2 RESEARCHES ON FUNGI 



be seen streaming slowly past the pore of a newly formed, convexly 

 bulged septum, along the terminal cell, and almost up to the growing 

 point. In some of the hyphae several of the terminal septa were 

 seen to be bulged forward toward the growing point. The pheno- 

 menon of the bulging forward of the terminal septum in a hypha, 

 which apparently does not occur in Fimetaria fimicola and Pyronema 

 confluens, was first observed in Rhizoctonia solani and it will be 

 treated of more fully in connection with that species. 



In a Ciboria hypha in which streaming was fairly rapid a vacuole 

 was seen to be torn loose from the side of a cell and to be carried by 

 the protoplasm up to the next septum. 



The Hymenomycetes. — The general structure of the mycelium 

 of the Basidiomycetes resembles that of the Ascomycetes in being 

 cylindrical, branched, and divided up into cells by means of septa 

 each of which has a small central pore occupied by a protoplasmic 

 bridge. Since we know that protoplasmic streaming takes place in 

 Pyrenomycetes and Discomycetes, there seems to be good reason 

 to suppose that it also takes place in Hymenomycetes, Gastro- 

 mycetes, Uredineae, Ustilaginaceae, and Tilletiaceae. With this in 

 mind and realising that protoplasmic streaming and not mere 

 diffusion may well be the means by which the mycelium of Agari- 

 caceae or Polyporaceae, etc., sends to a rapidly growing fruit-body 

 great quantities of building substances, I determined to seek for 

 streaming in the mycelium of some typically basidiomycetous fungi. 

 The species chosen were Hymenomycetes and, in the end, my efforts 

 were crowned with success. 



A search for streaming in the Hymenomycetes at first yielded 

 negative results. Mycelia of Coprinus sterquilinus and C. lagopus, 

 grown in hanging drops, were repeatedly and carefully examined, 

 but no definite streaming movement could be observed in them. It 

 is true that the vacuoles were seen to be constantly changing their 

 shape and that the Woronin bodies individually often moved from 

 one to six diameters of a hypha up or down a cell very rapidly, but 

 nothing was observed to suggest a mass flow of the cytoplasm in 

 any one direction. The vacuoles were attached to the cell- walls. 

 In these Coprini, the general cytoplasm, except for the sparsely 

 distributed Woronin bodies, appears extremely hyaline when viewed 



