20 BULLETIN 1053, U. S. DEPARTMENT OF AGRICULTURE. 



to consist for the most part of oidia, with a moderate amount of 

 strand development on the surfaces and between the blocks. This 

 growth on wood may turn wood brown in its later stages of devel- 

 opment. No fruit-body formation has been observed in either the 

 agar or wood cultures. 



On malt agar the first growth of Lenzites trdbea (the secondary 

 mycelium) is white and has the same damp-powdery appearance, 

 due to the pressure of oidia, as L. sepiaria. This secondary myce- 

 lium is much more abundant than that of L. sepiaria, however. In 

 ten days or more this growth is followed by the tertiary mycelium, 

 which begins in patches and later more or less entirely overgrows 

 the secondary mycelium. It is thick, fluffy woolly, more or less 

 bunchy, in color pale yellow-orange to light ochraceous buff, and 

 shows no sign of the powdery appearance, because it forms no oidia. 

 It forms large yellow-orange masses of mycelium in the upper ends 

 of agar slants and fruits quite abundantly after a month or more. 

 On wood the first mycelium is white, and no oidia formation has 

 been noted. The mycelial growth is more abundant than that of 

 Lenzites sepiaxria, more bunchy and patchy, and becomes colored as 

 noted upon malt agar. 



Trametes serialis on malt agar makes a white cottony growth, 

 slightly patchy at times, and occasionally may be more fluffy and 

 thick near the periphery of the culture. In later stages there is a 

 tendency toward a snuff-brown color. In tubes the superficial myce- 

 lium forms a fluffy white mass, which grows up the walls. The upper 

 end of the slant becomes sepia or auburn with age and occasionally 

 develops a thick brown mass of mycelium which forms pores. On 

 wood this fungus at first makes a thick growth over the individual 

 blocks with some strand formation and then continues to form an 

 abundance of white mycelium which fills the interstices between the 

 blocks, finally covering the wood with a thick snow-white mass in 

 three or four months. This mycelial growth may become more or 

 less suffused with a brownish tint and may form a brown exudate 

 an places. When the blocks are removed from the flasks after six 

 months or more, they are covered with a thick white mass having 

 a consistency of cream cheese. Abortive irpiciform fruit bodies, 

 having plates instead of normal pores, are formed after six months 

 in these block culture flasks and occasionally resupinate poroid forms 

 develop upon the slanting sides of the flasks, connected with the 

 mycelial mass by thick strands. 



Single-spore cultures of Fomes roseus form a white cottony 

 growth on malt agar, thicker and more compact than those of 

 Trametes serialis, having the appearance of washed cotton flannel. 

 They are white in color when fresh, becoming avellaneous or snuff 



