THE RED ROT OF CONIFERS 



11 



Figure 2, copied from Hartig, shows 

 more clearly than can be explained the appear- 

 ance of the mycelium in the tracheids and the 

 gradual solution of the lignin brought about 

 by the enzym of the fungus. 



VI. CULTURAL STUDIES 



Specimens of diseased wood were secured 

 from several sections of the State, though 

 mostly from forests near Burlington, in 

 August, 1912, the trees being in various stages 

 of decay. These specimens were examined 

 microscopically and the fungus was grown on 

 lima bean agar (Clinton's formula) and a syn- 

 thetic agar composed of peptone and the neces- 

 sary salts, which was strongly acid in its re- 

 action. 



Inoculation methods. Some samples for 

 inoculation were taken from standing trees on 

 which fruiting bodies had developed, others 

 from logs or sawed lumber in lumber yards, 

 Figure 2. A tracheid an ^ in two cases successful cultures were made 



of Pinis sylvestris which f ro m particles of wood taken from a knot-hole 



has been decomposed by 



Trametes Pini. The pri- in a suspected pine upon which no fruiting 



body could be found. The mycelia obtained 

 from all these sources showed noticeable uni- 

 formity in their growth or media. Particles of 

 fruiting bodies also were used for inocula- 

 tions and, in comparison with each other and 

 the cultures made directly from wood, gave 

 equally uniform results. 



Most of the inoculations were made 

 directly from the specimens of wood. By 



carefully handling the specimens with sterile forceps and cutting 

 away the external portions of the wood with a sterile knife, 

 small particles of the diseased wood fiber were obtained, which, when 

 introduced upon the surface of the tubed media, gave about 90 percent 

 of pure cultures. 



Mycelial growth. At first the mycelium made slow growth, from 



mary cell-wall has been 

 completely dissolved as 

 far as aa. In the lower 

 portion of the figure the 

 secondary and tertiary 

 walls consist of cellulose 

 alone, in which granules 

 of lime are distinctly 

 recognizable, b; fila- 

 ments penetrate the 

 walls and leave holes 

 behind, d. e. 

 (After Hartig). 



