234 MYCOLOGY 



fectly still air placed above a horizontal sheet of paper fall vertically 

 downward and produce a spore print of radiating lines of spores cor- 

 responding to the interlamellar spaces. The number of spores liberated 

 in Agaricus (Psalliota) campestris (Fig. 94), 8 cm. in diameter, was 

 1,800,000,000 spores. Coprinus comatus formed 5,000,000,000 spores. 

 Such discharge under normal conditions is continuous, but by exposing 

 the gills to ether, or chloroform vapor, it ceases. BuUer determined 

 that the four spores on each basidium are discharged successively leav- 

 ing the sterigmata a few seconds or minutes of one another, so that an 

 entire mushroom will discharge in total about a million spores a minute 



Fig. 94. — Meadow mushroom, Agaricus campestris. A, View of under surface; 

 a, annulus; g, gills; B, side view; s, stipe; p, pileus or cap. {From Gager, after W. A. 

 Murrill.) 



for two or more days. The rate of fall of hymenomycetous spores ranges 

 from 0.3 to 6.0 mm. per second; those of the mushroom shortly after 

 they have left the gills fall at a speed approximately i mm. per second. 

 The path described by a spore in its fall has been called a sporabola. 

 Buller has divided the fruit bodies of the Agaricace^ into two types, 

 the Coprinus comatus type and the Agaricus campestris type. The 

 deliquescence in the first type is an autodigestion, which renders impor- 

 tant mechanic assistance in the process of spore discharge, where the 

 process proceeds in succession from below upward, so that autodiges- 

 tion refnoves those parts of the gills from which the spores have been 



