THE COPRINUS TYPE OF FRUIT-BODY 203 



a black spore-deposit collects upon it, which is similar to that 

 produced under the same conditions by an ordinary Agaric. 



In nature, the fluid produced by autodigestion is largely got 

 rid of by evaporation. The amount of it adhering to the pileus 

 rim varies considerably according to the state of the weather. In 

 very dry weather, it often happens that actual drops are not formed 

 at all. On the other hand, dripping is favoured by a saturated 

 atmosphere, and was found to take place regularly with fruit-bodies 

 placed in a damp-chamber. 



Two independent observers have informed me that they have 

 been surprised by finding that the drops hanging from the pileus 

 of certain fruit-bodies were red instead of black. In one case the 

 colour was described as "just like that of red currants." I, myself, 

 have never seen any red drops, but can scarcely doubt their 

 occasional occurrence. Possibly the red drops were merely ex- 

 creted from the exterior of the pileus like those given out by 

 Fistulina hepatica or Lentinus lejrideus, and they may have had 

 no connection with the process of autodigestion. 



A fruit-body begins to liberate its spores as soon as it has become 

 bell-shaped and the lower ends of the gills have separated. The 

 spores are projected violently from their sterigmata into the spaces 

 between the gills, where they describe sporabolas, and thus escape 

 into the outer air. Proofs that the four spores of a basidium are 

 shot off in succession in the course of a few seconds or minutes have 

 already been given. 1 The nature of a sporabola has likewise been 

 dealt with. 2 Convincing proof that the spores are liberated into the 

 air may be obtained, not only by collecting the thick black spore- 

 deposit on white paper, but also by the beam-of-light method. 

 When a fruit-body is placed upright in a closed beaker, the beam 

 of light reveals clouds of spores emerging from the gills and 

 becoming scattered by convection currents in the enclosed air. 3 



Spore-discharge from a gill is not general all over its surface 

 as in a Mushroom, but extremely local. It begins on both sides 

 simultaneously, towards the base along two opposite and very 

 narrow zones (Plate II., Fig. 8, s), which run parallel to and adjoin 

 the oblique, free, inner gill edge. We may refer to a part of 



1 Chap. XL, Method IV. 2 Chap. XVII. 3 Cf. Chap. VII. 



