62 BULLETIN 1298, U. S. DEPARTMENT OF AGRICULTURE 
MUCEDINACEAE 
Torulopsis rosea Berl. — Hyphae obsolete; cells ellipsoid or globose, 
rose-colored en masse, usually budding at the ends, seldom forming 
chains. Agar normal; pulp slightly pink. Isolated from ground 
wood. Common. 
Oidium sp. — Cultures wet and mucilaginous, occasionally mealy; 
septate hyphse irregularly branched, more distinct than is usual in 
Oidium, but they break up into typical oidia (simple segmentation 
of the hyphse). The oidia vary considerably in length; are at first 
cylindrical, but when separated become rounded at the ends. (See 
PL XVI, fig. 8.) This fungus causes little damage to the pulp. In- 
fected areas are generally lighter in color than normal pulp. This 
fungus is probably responsible in part for pulp in very wet condition 
souring. Isolated from ground wood (62020-1). Common. 
Papulospora nigra Hotson. — Mycelium scanty, white, becoming 
dirty gray in very old cultures, clamp connections conspicuous; bul- 
bils colorless when young, becoming dark brown, then black, at 
maturity (PL XX, fig. 1), produced in large numbers, soon making 
entire culture appear black. No other means of reproduction known. 
The clamps indicate the relation of this species to the hymenomy- 
cetes. Hyaline mycelium penetrates the pulp; black bulbils are pro- 
duced on surface. Isolated from ground wood (32019-7). Rather 
common. 
TricJioderma spp. — Nine cultures varying enough to be of distinct 
species were isolated. Mycelium scanty, cottony, white or yellow, 
or compact, soggy, appressed, cream-colored to yellow; conidia in 
heads at tips of the many branches of the fertile hyphae (PL XVI, 
fig. 7) , scattered uniformly over surface, in- small or large patches, 
or around the margin; conidia white, bluish gray, or reed-yellow to 
fight or dark American green. Agar normal, yellowed, or browned; 
infected pulp normal in color, yellow or green. These species produce 
large masses of spores, most of which are American green, and make 
the pulp "dirty." Some cultures dissolve cellulose. Isolated from 
ground wood (82219-10, 32019-1), from sulphite pulp, from river 
water (6520-2) . All very common. 
TricJioderma sp. — Mycelium scanty, white, rapidly covering the 
surface of the agar; small, white, compact bunches of conidiophores, 
appearing early, scattered over the surface. As conidia mature 
these patches become pinkish cinnamon and, finally, cinnamon. 
This fungus causes a slight browning of the pulp. Isolated from 
ground wood (10918-4). Observed twice. 
Aspergillus spp. 8 — This groun produces globose conidia in chains 
at the tips of sterigmata, which in turn are born on the inflated heads 
of the fertile hyphae. (See PL XVI, figs. 12 and 13.) None of the 
species discolor pulp, but all sporulate abundantly on the surface. 
Aspergillus niger van Tiegh. — Mycelium scanty, superficial; but 
next to the glass, in slant culture, there is often a naphthalene yellow 
or citron-yellow sheet. The surface of cultures is soon covered with 
a coal-black, powdery mass, formed by conidia. Isolated from 
bleached sulphite and soda pulp. Very common. It is almost 
invariably present in the " sooty" blotches on pulp. 
8 Aspergillus and Penicillium should properly be classed with the ascomycetes, but since the ascigerous 
stage is known for only a few, they are often placed with the fungi imperfecti. 
