14 BULLETIN 759, U. S. DEPARTMENT OF AGRICULTURE. 
masses, very small at first, but often extending until they merge. 
The apothecium is merely a rounded, sometimes flattened, firm mass 
of asci and paraphyses which crumbles when crushed (PI. III, B). 
The gray color of the mass becomes darker with the increased age 
of the culture, and finally is dark brown or almost black. The rusty 
brown color that is seen early in the development of the culture is 
usually found to have permeated the agar slightly by the time the 
fruiting stage is reached. A greater amount of color is usually 
found in cultures which have relatively few colonies and which 
fruit. but little. Retardation of the growth of the cultures by low 
temperature appears to allow the color to diffuse farther through the — 
agar. In cultures which grow rapidly, the yellow color may be 
diffused only in the upper part of the slope where the layer of agar 
is thin. 
Pseudopeziza trifolii: The development of Pseudopeziza trifolii 
on this culture medium differs from that described for P. medicaginis 
only in the details here stated. The color which develops in the stro- 
mata as they develop is dark gray, becoming black, with no trace of 
brown. The fungous colonies appear a little more vigorous and co- 
alesce into a more solid crust on the surface of the medium than those 
of P. medicaginis. The fruiting structures appear more typical (Pi. 
III, A), being flat on top, but are not surrounded by a wall. The 
substrate never becomes discolored. 
Potato-dextrose agar.—Cultures of both fungi grow very rapidly 
on potato-dextrose agar. When the colonies are much crowded the 
leathery surface growth becomes crumpled. 
Pseudopeziza medicaginis: Color at the end of four weeks brown, 
sprinkled with a few black stromata; substrate decidedly colored; 
apothecia produced in small numbers. 
Pseudopeziza: Culture coal black, with slight amount of frosty 
mycelium. There is a slight staining of the substrate. 
Lima-bean agar.—Pseudopeziza medicaginis: Growth yellowish in 
varying degree; no fruiting observed; substrate shows discoloration. 
Pseudopeziza trifolii: The growth is a rough black mat with a little 
white mycelium. The substrate shows slight discoloration. 
Corn-meal agar.—Pseudopeziza medicaginis: Growth not vigor- 
ous; colonies scattered, black, and distinctly raised from the sur- 
face, which appears as though sprinkled with coarse black pepper; 
apothecia minute and scattered. 
Pseudopeziza trifolii: Growth black, almost submerged in the sub- 
strate; colonies tend to remain separate, though the slope appears a 
solid black color; scattered minute apothecia occur. 
Liquefaction of gelatin——Both fungi cause rapid liquefaction of 
gelatin. 
