356 RESEARCHES ON FUNGI 



from between the gills with the spores. The first cystidia to suffer 

 destruction are those which are present along the lower parts of 

 the gill-edges ; ^ and their cell-walls are destroyed and collapse 

 ensues in the manner already described for the cystidia of Coprinus 

 atramentarhis.^ Unless the marginal cystidia were reduced to fluid 

 in this way, they would act as obstacles to the first spores to be 

 discharged by obstructing their path of fall. After the destruction 

 of the marginal cystidia, and only then, spore- discharge begins ; 

 and the first spores to be shot away are always those situated 

 on the basidia in a zone immediately above the edge of the gill 

 where the destroyed marginal cystidia were located. The cystidia 

 on the faces of the gills are destroyed by autodigestion in succession 

 from below upwards, just as in Coprinus atrameniarius ; and here, 

 also, each cystidium disappears some minutes before the basidia 

 which are immediately above it begin to discharge their spores. 

 Thus the cystidia on the gill-sides cannot become hindrances to the 

 fall of the spores. 



Effect of the Weather on the Fruit-bodies. — The successful 

 discharge of the spores in the manner that has been described in 

 the preceding pages is dependent to some extent on the weather. 

 When the air is sufficiently moist, the spores are shed and auto- 

 digestion takes place from below upwards on each gill from the 

 bottom to the top of the pileus. However, when a fruit-body 

 owing to transpiration loses water beyond a certain amount, the 

 spores cease to be discharged, the basidia collapse, the process of 

 autodigestion makes no fiu*ther progress, the gills shrivel, and the 

 pileus-fiesh dries. Thus, in very dry weather, fruit-bodies are 

 apt to dry up with all their parts well preserved although much 

 shrunken. When such drying takes place, the beautiful mechanism 

 for the production and liberation of the spores is rendered abortive. 

 The millions of spores which have been produced by the basidia 

 cling to the gills, sink down to the ground with the collapsing 

 fruit-body, and thus fail to be dispersed by the wind. 



1 Cf. Fig. 118, B, s, p. 278. 2 pp 286-289. 



