SAP-STAIN, MOLD, AND DECAY IN GREEN WOOD. 
7 
extent. The starches, sugars, and oils stored in the sapwood and pith 
rays, together with the contained air and water, probably exert an 
influence upon the advancing hyphse and limit largely the growth of 
the fungus to the sapwood and the pith rays, where the sap-stain is 
mainly to be found. Practically no invasion of the heartwood takes 
place (Yon Sclirenk, ^7, p. 19). (PI. I, fig. 3.) 
THE SAP-STAIN FUNGI. 
The relation of a fungus to the bluing of wood was first noted by 
Hartig (77, 18). He describes the organism which causes the so- 
called “ bluing ” of conifers, especially dead or dying pine that has 
been injured by caterpillars, as C eratostoma piliferum. He notes 
that it ma}^ also appear in damp firewood. According to Hartig, 
the brown mycelium very quickly penetrates the trunk through the 
medullary rays. He states that probably on account of the de¬ 
ficiency in moisture content the heartwood is avoided by the mycelium, 
whereas the sapwood often becomes quickly invaded and decomposed. 
Although described by Fries (13; see also Berkeley, d), who placed 
it in the genus Sphaeria, the fungus was later transferred by Fiickel 
(14\ see also Ellis and Everhart, 10) to the genus Ceratostoma. Sac- 
cardo (39) still later divided the genus Ceratostoma and placed those 
species which possess colorless spores in a new genus, Ceratostomella. 
Winter (58) ,in a subsequent revision of the family included the fungus 
as Ceratostomella pilifera Fries under the new genus. It is now 
known as Ceratostomella pilifera (Fries) Winter (Engler and 
Prantl, 29). 
Figure 2 illustrates the fruiting bodies of this fungus. With the 
aid of a magnifying glass one may often see them clearly as stiff 
black hairs, approximately 1 millimeter (l/25th of an inch) in 
length, 5 swollen at the bases, and forming, en masse, a dark hairy 
covering on the ends and tangential surfaces of stained sapwood. 
These growths when well developed are sometimes referred to by 
lumbermen as “ whiskers.” 
Many species of Ceratostomella have been listed by Saccardo (Jfi). 
Though no reference is made to the fact, it is probable that a. number 
of these stain wood. 
The life histories of many species of Ceratostomella found on 
stained wood have been worked out by Yon Schrenk (41 ), Hedgcock 
(19 ), and Rumbold (37) in this country and by Munch (31) in 
Europe. In connection with the study of several chromogenic fungi 
which discolor wood, Hedgcock developed in culture a conidial stage 
of Ceratostomella superficially resembling Cephalosporium. Munch 
and Rumbold associated a Graphium stage with the development of 
5 In some species the length may exceed 2 millimeters. 
