FUNGI OF IMPORTANCE IN THE DECAY OF TIMBERS. 21 



brown with age in patches and at the upper ends of slants. The 

 writer's single-spore cultures from the annual form of the fungus 

 upon coniferous hosts have only rarely developed any pink color, 

 and then only a pale pinkish cast after 18 to 20 months of trans- 

 ferring. Single-spore cultures from the annual form upon Prunus 

 sp. have developed colors from pink to Mars brown in patches or 

 streaks. Tissue cultures from the annual form upon spruce have 

 taken on only a pale-pink color, but similar cultures from the per- 

 ennial form have developed a thick mat of mycelium old rose to 

 Mars brown. The same cultures, with the exception of the single- 

 spore cultures used in these experiments, have varied from transfer 

 to transfer both in color and character of growth. This growth may 

 be described as above, a thick mat, as in the tissue culture of the 

 perennial form, or varying, thick, irregular growths, as found in 

 other cultures. Layers of pores have been formed in the cultures 

 derived from sporophores, but not as yet in the single-spore cultures. 

 The culture of Fomes roseus used by the writer in this work is 'a 

 relatively slow grower, covering a 10-centimeter Petri dish in 12 

 days at its optimum temperature. 



On wood the slowly growing mycelium of the culture used eventu- 

 ally completely covers the blocks, but the growth is very thin, not 

 at all fluffy or abundant, and the interstices between the blocks are 

 not filled as they are by Trametes serialis or Lentinus lepideus. 

 There is no great mass of superficial mycelium formed. The growth 

 upon the blocks has the same washed-flannel appearance as have the 

 agar-plate cultures, has abundant strand formation, and may become 

 chestnut to argus brown in places in nine months or more. 



Young cultures of Lentinus lepideus on agar are light cottony or 

 felty, with more or less tendency to the formation of thin and thick 

 zones* of aerial mycelium. The inoculum turns snuff brown in two 

 weeks, and the rest of the aerial growth turns buckthorn brown to 

 cinnamon brown as it grows older, perhaps only in patches. In one 

 month the culture may develop numerous umbonate or tubercular 

 cushions of mycelium, which vary from white to Prout's brown, 

 exude droplets of a dark color, and have a distinct aromatic odor. 

 They are apparently either primordia of sporophores or abortive 

 Emit bodies. No well -formed sporophores have developed in the 

 writer's plate cultures. Strand formation is quite pronounced in 

 four to six weeks. In tubes the cultures are much the same as the 

 plate cultures. In the wood cultures in flasks the mycelial growth 

 i abundant, covering the blocks, ;it first white and later becoming 

 buckthorn brOWIl or bister in patches, forming abortive fruit bodies 

 in six to nine months. Clusters of Long thin crystals are formed 



