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C. H. CRABILL 
male and female strains. Plus is used in the present instance to denote 
a strain fruiting abundantly and minus to denote a relatively poor 
fruiting strain. 
In the II + colonies on the plates referred to above, the growth 
was typical of Strain II as it appeared when first isolated. The 
II — colonies grew rapidly but remained white for 12 days. They 
then began to take on the olive-green color characteristic of the species 
Fig. 3. Same as Fig. 2, 17 days old. Note that II — has produced numerous 
pycnidia from which the black spore masses are oozing. It was necessary to open 
the plates when photographing. The contaminations around the edge of the plate 
got in when the plate was photographed the first time. 
and in 20 days from the time of inoculation produced a few large 
pycnidia about the center of the culture (Figs. 2 and 3). Microscopic 
examination showed the mycelium, pycnidia and conidia all typical 
of C. pirinum. The — colonies were exactly like Strain I in morpho- 
logical and cultural features. 
It appeared that from Strain II there had arisen a poor fruiting 
strain identical with Strain I. Poor fruiting is here used in a relative 
sense. The minus strain produces great multitudes of spores from the 
few large pycnidia; but, when compared with the enormous numbers 
