164 DopnceE: METHODS OF CULTURE OF ASCOBOLACEAE 
cent of those raised to 45° C. germinated. All spores heated to 65°- 
75°C. germinated. Between 75° and 80° there wasa rapid falling off 
and at 93° C. only one spore of the thirty-nine germinated. There 
was also a marked difference in the time required for germination to 
begin. Inthe cultures heated to 65°-90° C. the mycelium had al- 
ready grown several millimeters when examined 24 hours later; the 
only spore germinated at 45° had just begun to send out the germ 
tubes at this time. When the time during which the spores were 
heated was lengthened to five minutes, the maximum temperature 
was lowered to 90° C. and the optimum was limited to 65°-70° C. 
ASCOBOLUS VIRIDIS Curr. var. ? 
Liquid decoctions were made from unheated soil gathered in” 
the habitat of the fungus; other decoctions were made from this 
soil heated to 180° C. for one hour, and from alkaline soil from 
North Dakota both heated and unheated. Agar media were pre- 
pared with each of the above decoctions. At least fifty different 
plates were inoculated and subjected to various degrees of heat 
ranging from — 5° C. for 24-48 hours, to 25°-75° C. for much 
shorter periods. Germination was obtained only in drop cultures 
made in a decoction of heated soil from the locality where the 
plants grew. Of the thousands of spores in Petri dishes containing 
this same liquid, none germinated. The spores germinated in 
the drop cultures could not be induced to continue their growth om 
the agar media. Fic. 2 and 3 show the manner in which the 
epispore breaks up as the spore germinates. 
ASCOBOLUS IMMERSUS Pers. 
The method by which the spores of A. immersus were getmi 
nated is the same as was used with the preceding species. The 
results of my experiments are given in TABLE VI. 
THECOTHEUS PELLETIERI (Crouan) Boud. 
The methods by which this fungus may be obtained in cultures 
on the natural substratum have been well described by Overto? 
(1906). 
The large size of the spores and the fact that all of the thirty-tW° 
usually lie together on the slide arranged to catch them as they aa 
ejected, make it possible to remove them without much dangef 
introducing the spores of other species. The agar medium was made 
