FUNGI OF IMPORTANCE IX THE DECAY OF TIMBERS. 21 
brown with age in patches and at the upper ends of slants. The 
writers 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 
fruit bodies. Xo 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 
is abundant, covering the blocks, at first white and later becoming 
buckthorn brown or bister in patches, forming abortive fruit bodies 
in six to nine months. Clusters of long thin crystals are formed 
