PSALLIOTA CAMPESTRIS 



453 



(Levine, 1914). The marginal growth of the gill system is also 



familiar in the mushrooms. The columella comes into being exactly 



as does the stipe of mushrooms. Indeed, we might well speak of 



stipe and pileus of Secotium, rather than of peridium and columella. 



The basidia have the shape, 



size, and arrangement found in 



agarics. The copious branching 



of the gills exceeds anything 



seen in agarics. The failure of 



the cap and gills to expand, the 



drying up of the trama into 



a friable mass of tissues and 



spores, the olive-brown color of 



the spores, and the freedom of 



the spores to ' puff ' when the 



exposed mass is touched, are all 



lycoperdinean characters." 



A simple forking of the gills 

 occurs in certain Agaricineae, 

 e.g. Russula furcata and Can- 

 tharettus cibarius ; but it is a 

 perfectly normal phenomenon 

 and in no way interferes with 

 the liberation of the spores. On 

 the other hand, an irregular 

 branching and anastomosis of 

 the gills sometimes occurs in 

 Pholiota erebia (Fig. 157), etc., 

 and I myself have observed it 



in a Psalliota campestris fruit-body which I gathered in a field near 

 Banbury, England, and in some large Coprinus niveus fruit-bodies 

 which I grew in pure cultures on horse dung at Winnipeg. Here the 

 lamellar irregularities were certainly abnormal and seriously inter- 

 fered with spore-liberation. I am inclined to believe that the 

 copious branching and anastomosis of the gills in Secotium 

 agaricoides arose in the first place as an abnormality affecting 

 simple radial gills and that it is therefore comparable with the 



FIG. 155. Secotium agaricoides. A full- 

 grown conico-cylindrical fruit-body 

 showing its characteristically peg- 

 like stipe and a longitudinal crack 

 in the upper part of the peridium. 

 Collected at Winnipeg by the 

 author. Natural size. 



