4 RESEARCHES ON FUNGI 



basidia, the Curtus Sub-type resembles very closely the Comatus 

 Sub-type ; but in its small size, in possessing grooves above the 

 gills, in the flattening of the pileus before the process of spore- 

 discharge begins, and in th& very small amount of autodigestion, 

 the Curtus Sub-type appears to stand very close to the PUcatiUs 

 Sub-type. The Curtus Sub-type seems to have the structure for 

 spore-dispersal which one would expect to find in the Comatus Sub- 

 type if this were to be very much decreased in size. The weight of 

 very small gills is very much less than that of very large ones. In 

 a small fruit-body, therefore, the flesh necessary to support and 

 raise the gills can be very small in amount, and the raising of the 

 gills can be accompUshed by the little mass of flesh at the disc. 

 In a massive fruit-body, such as that of Coprinus comatus or C. 

 atramentarius, the flesh has more work to do, and its thickness must 

 therefore be relatively greater than in a small fruit-body and its 

 distribution above the gills must be more even. 



Representative Species.— The only species with which I am 

 acquainted that belongs to the Curtus Sub-type is Coprinus 



curtus Kalch. 



Coprinus curtus : CuliMres.— Coprinus curtus is a coprophilous 

 species which produces small fruit-bodies gregariously at the surface 

 of horse-dung balls in pastures. At Winnipeg, throughout the 

 winter months, one may readily obtain cultures of the fungus from 

 (1) fresh stable manure or (2) frozen dung-balls. 



(1) Fresh horse-dung balls from a stable are placed in a large 

 crystallising dish which is covered with a glass plate and then set 

 in diffuse dayhght on a laboratory table. At the end of ten days, 

 almost invariably, fruit-bodies of Coprinus curtus begin to appear 

 as tiny foxy-red rudiments scattered at the surface of the dung- 

 balls ; and, after about thirteen days, successive crops of fruit- 

 bodies come to maturity daily for several days in succession (Fig. 1). 



(2) Horse-dung balls dropped in the snow on the streets of 

 Winnipeg during the winter become frozen sohd in a few minutes. 

 When such balls, which may have remained frozen for several 

 weeks or even months, are taken into the laboratory and set in a 

 covered crystalUsing dish, they soon thaw and, after about ten days, 

 fruit-bodies of Coprinus curtus begin to appear at their surface m 



