1230 Wisconsin Academy of Sciences, Arts and Letters. 
Physanxm nefroideum Rostafinski. 
1875. Physarum nefroideum Rost., Mon., p. 93. 
Macbride: “Sporangia gregarious, sessile, stipitate, or even 
plasmodioearpous; when stipitate, globose, depressed, or anon re- 
niform, usually concave or umbilicate below, the peridium 
strongly calcareous, cinereous-white; stipe variable, generally 
tapering upward, always distinctly deeply plicate-furrowed; 
varying in color from nearly pure white, through different shades 
of gray to brown fuliginous or black; hypothallus none or ob¬ 
scure; columella ;nione ; capillitium abundant, the white lime- 
knots varying in size and shape, connecting by rather long' hya¬ 
line threads, with here and there an empty node; spore-mass 
black, by transmitted light dark, sooty brown, minutely papil¬ 
lose, 10-11.5^.” Macbride says also that, while normally stipi¬ 
tate, it often shows from the same plasmodium all sorts of forms. 
The amount of lime also varies, especially in the capillitium, 
where there is always a tendency to the formation of something 
like a pseudo-columella. 
Lister adopts the name P. compressnm Alb. and Schw. He 
describes the sporangia as erect, splitting along the upper ridge,' 
scattered, closely aggregated or confluent. The stalk never has 
a chalk-white fracture at the base. He finds the spores to be 
dark purplish-brown, more or less spinulose or echinulate and 
from 9-14/x in diameter. He finds much difference in size and 
roughness of the spores in sporangia from the same cultivation. 
He finds also American specimens with nearly globose sporangia, 
and buff or white, long or short,, stout stalks, and says that these 
forms are more symmetrical than European forms. 
The description in Saccardo of the species P. cowpressum A. 
and S., with the synonym P. nefroideum Rost, and the descrip¬ 
tion in Massee of the species P. nefroideum Rost., are identical, 
and offer no material departure from the above. This descrip¬ 
tion, however, calls the spores globose or angularly subglobose, 
11-13/x in diameter, minutely verruculose. 
The abundant material which I have agrees with MacbrideV 
description excepting that I find the spores to be 9-11 y in di¬ 
ameter. 
My specimens are mostly upon the bark and wood of decayed 
