CHROMOGENIC FUNGI WHICH DISCOLOR WOOD.) 65 
trates rapidly the sap wood of dead and dying trees, giving 
it a peculiar blue tint whose color is hard to explain, since 
the mycelium of the fungus in the cells of the wood is a 
dark brown. It has also been found in the sapwood of 
species of Abies, Quercus, Fraxinus, and other genera. 
Ceratostomella pilifera grows readily upon a large num- 
ber of culture media. Pine decoction agar made from the 
bark and sapwood was found an excellent medium for its 
cultivation. Two distinct fruiting forms were observed in 
all the varieties, the conidial and the perfect or perithecial. 
MYCELIUM. 
When either the conidia or ascospores are sown In pine 
agar plates, germination takes place in a few hours, and in 
two days colonies with a white hyaline mycelium develop. 
The filaments areseptate, and, asa rule, branch alternately. 
In a day or so upright hyphae, either simple or branched, 
are sent out, upon which are borne branching whorls of 
conidia. Inthe course of a week or so, portions of the 
mycelium in the older region of the colonies develop with 
thicker walls and assume a brown color. From these dark 
colored filaments the perithecia originate. 
The first growth of the mycelium is usually sparse, 
but under favorable conditions a secondary profuse 
growth with a fluffy white appearance develops, which 
bears conidia, and the formation of perithecia is retarded. 
Such a growth is formed on some of the richer media 
made from pine and other plant decoctions. Under these 
conditions the development of conidia is enormous, and 
the number of perithecia is decreased somewhat. Cultures 
on the sapwood of trees in test tubes bear both stages of 
the fungus abundantly. On the heartwood, however, but 
few conidia are formed, the mycelium is almost invisible to 
the eye, and perithecia are either sparse or entirely absent. 
The filaments of the fungus never penetrate deeply into 
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