CONTROL OF DECAY IN PULP AND PULP WOOD 63 
Aspergillus fumigatus Fres. — (1) Mycelium sparse, superficial, 
white; entire surface covered with dark bluish gray-green spores 
which become deep slate olive in old cultures. Agar greenish yellow. 
This fungus dissolves cellulose. Isolated from river water (6520-1) 
Common. (2) No superficial mycelium; entire surface covered with 
dark bluish-gray conidia which become deep slate olive in old cultures. 
Agar purple-brown. Isolated from sulphite pulp. Common. 
Aspergillus flavus group. — (1) No superficial mycelium; surface 
covered with parrot-green conidia which later become brownish olive. 
Isolated from sulphite pulp. Common. (2) Mycelium loose, fluffy, 
white, around the margin of young cultures, but soon covered with 
mignonette-green conidia which become brownish olive in very old 
cultures. Isolated from bleached sulphite. Common. 
Penicillium spp. — Conidia globose or ellipsoid, borne in chains on 
the tips of sterigmata, which are small branchlets at the top of the 
unequally verticillately branched, uninflated fertile hyphaa. (See 
PL XVI, figs. 9 and 14.) Some of the species discolor the pulp; all 
of them produce spores in sufficient numbers to make the pulp 
" dirty." The species isolated may be described briefly as follows: 
Penicillium orevicaule group. — Mycelium scanty, appressed, soon 
covered with pinkish buff to avellaneous conidia, which later become 
cinnamon brown. Agar slightly darkened; pulp not discolored. 
Isolated from ground wood (81318-2). Common. 
Penicillium divaricatum group. — Mycelium scanty, superficial, soon 
covered by a smooth layer of conidiophores with light brownish-olive 
conidia. Agar very dark brown; pulp slightly browned. Isolated 
from ground wood. Common. 
Penicillium pinophilum Hedge. — Mycelium scanty, superficial 
when grown on malt agar. Cultures soon become dark bluish 
glaucous mixed with a little yellow-green due to conidia. Agar dark 
red; pulp pink to red. Seldom produces large numbers of spores on 
pulp, but the reddening is sufficient to give an off-color paper. 
According to Thorn (26) it produces orange to red stains in pine wood. 
Isolated from ground wood (112217). Very common. 
Penicillium purpurogenum O. Stoll. — Similar to P. pinophilum 
when grown on malt agar, but no yellow present in the spore surface, 
which is somewhat smoother. Agar red to purplish vinaceous in old 
cultures; pulp pink to purplish red. Isolated from ground wood 
(10918-11) and sulphite pulp. Very common. 
Penicillium commune Thorn. — Mycelium scanty, soon covered 
with celandine-green conidia, which become gnaphalium green or 
even dark olive. Older cultures more or less overgrown with white 
floccose mycelium. Agar and pulp normal. Isolated from ground 
wood (10918-3). Common. 
Undetermined Penicillium species. — Nine cultures, varying enough 
to be distinct species, were isolated. Mycelium soggy, appressed, or 
cottony; floccose, scanty, or abundant; white, reed yellow, or colonial 
buff; conidia bluish gray-green, grayish blue-green, pistachio green, 
glaucous, citron or glass green to fight brownish olive, ecru olive, 
mytho, dark ivy, or dark American green; surface dry, or covered 
with droplets of clear, amber, or pink liquid. Agar normal, yellow, 
green, or brown; pulp normal or slightly browned. One culture dis- 
solves cellulose. Isolated from ground wood (10918-9, 82219-12), 
sulphite pulp, soda pulp, and river water (6520-3) . All very common. 
