SAP-STAIN, MOLD, AND DECAY IN GEEEN 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 (Von Schrenk, Ifl, 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 (^7, 18). He describes the organism which causes the so- 

 called " bluing " of conifers, especially dead or djdng pine that has 

 been injured by caterpillars, as C er at o stoma pillferum. He notes 

 that it may 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, G), 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- 

 carclo (39) still later divided the genus Ceratostoma and placed those 

 species which possess colorless spores in a new genus, Ceratostomella. 

 Winter (68) ,in a subsequent revision of the family included the fungus 

 as Ceratostomella pilifera Fries under the new genus. It is now 

 known as Ceratostomella pihfera (Fries) Winter (Engler and 

 Prantl, ^P). 



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,^ 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 {4-0). 

 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 Von Schrenk (^-?), Hedgcock 

 (19), and Rumbold (37) in this country and by Miinch (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. Miinch 

 and Rumbold associated a Graphium stage with the development of 



^ In some species the length may exceed 2 millimeters. 



