Some Wood-Staining Fungi. B. D. MacCallum. 233 
occurs so commonly in Great Britain, although it has not been 
recorded, and Miinch’s paper is not readily accessible. It is 
perhaps the easiest species to study, for although it is almost 
inextricably entangled with other fungi on Pinus sylvestris it 
produces a nearly “‘pure” growth on Picea excelsa. However, 
it may easily be overlooked, as the timber of the spruce is quite 
unstained. Miinch is not quite certain how far C. Piceae stains 
wood, but states that fallen timber is sometimes blue, some- 
times slightly darkened and sometimes quite unstained. So far 
as my observations go, in Scotland spruce timber is quite un- 
stained even when perithecia occur thickly all over the surface, 
and, although C. Piceae occurs very frequently on badly stained 
Pinus sylvestris, | have never found it unaccompanied by other 
fungi. Moreover, pure cultures on sterilised pine blocks caused 
only a very slight discoloration. Certainly there was no trace 
of the characteristic blue colour always associated with attacks 
of C; Pins: 
The principal media used for the cultivation of the fungus 
have been pine and spruce decoction agar (or gelatine) and 
plum agar. Very successful growths also were made on sterile 
blocks of moist sap-wood in deep Petri dishes or narrow strips 
in test tubes. 
Fully developed perithecia were found throughout the autumn, 
and from the sticky mass on the top of the beak, streak cultures 
of ascospores were made. The ascospores germinate readily, 
and, after two days, a small mycelium of delicate, white, 
branching hyphae is formed. At the end of the second day 
conidia begin to appear, and on the third day the mycelium has 
produced numerous conidiophores, bearing conidia of the Clado- 
sporium type (Pl. IX, fig. 2). 
The conidiophores, which arise in the submerged part of the 
mycelium as well as aerially, are sometimes single and short, 
but more often they branch, the most characteristic form con- 
sisting of a fairly long stalk-like portion, from the end of which 
four to six branches radiate out, and these branches may branch 
again or conidia may be abstricted from their ends (PI. IX, fig. 2). 
The whole conidiophore breaks up very readily and the conidia 
bud on the surface of the agar forming a yeast-like mass. 
The size of the conidia varies enormously, the length being 
4-15 p, the width 2:5—3°5 pw. 
In hanging drops of pine decoction the mycelium may produce 
conidiophores of this type, but more often there is a simple 
conidiophore, at the apex of which a whorl of conidia is formed 
(Pl. IX, fig. 2 6). These conidia vary very little in size, being 
6-8 w long and 2:5—3-5 uw wide. 
In weak pine-decoction agar or gelatine, conidia of this second 
