276 BOTANICAL GAZETTE [OCTOBER 
On old cardboard, Cambridge, Massachusetts, and on hardwood chips, 
Seattle, Washington. 
Papulospora nigra was obtained from gross cultures of old 
- cardboard in the cryptogamic laboratories of Harvard University, 
and on similar cultures of chips in the botanical laboratory of the 
University of Washington, Seattle. When the bulbils appeared, 
pure cultures were made in a manner similar to that already 
described. This species has been grown on a variety of media for 
8 years without the perfect condition being obtained. The myce- 
lium is white and remains so throughout the period of rapid growth. 
Only when the hyphae get old do they begin to change color, becom- 
ing brownish or smoke colored. The primary mycelium is pro- 
cumbent and on most media is inconspicuous, but becomes more 
or less flocculent or cobwebby on bran or prune agar. When 4 
culture becomes old, the whole surface is covered with black bulbils 
which completely obliterate the mycelium. The hyphae frequently 
contain many large, conspicuous oil globules (figs. 40-42). The 
mycelium also has quite prominent clamp connections, a condi 
indicating its relation to the Basidiomycetes. 
The bulbils of this species resemble closely those of P. anomala 
Hotson (6) in size, form, and color. They are readily distinguished, 
however, by their mode of development. In the latter species the 
_ bulbils arise from ‘‘slightly swollen, colorless, intercalary cls 
. . - . about 4 or 5 w in diameter, sometimes projecting consider- 
ably and resembling short stunted branches; at other times 
_ base of a short lateral hypha swells slightly and forms the primor- 
dium.” From these primordial cells branches are sent out in 
different directions, the lateral walls of the basal cells adhering — 
firmly together and becoming eventually incorporated into the 
bulbils. It will be seen that the development of the bulbil of = 
: P. nigra is quite different from this. It has already been shown 
may readily be distinguished from those of Corticium alutaceum, — . 
2 thos of Grandinia ersten by t a oe 
ation of P. aurantiaca that the bulbils of P. mgr 
