EXPLANATION OF PLATES 271 



are still in progress, m, marginal band on gill edge covered with cystidia. 

 Natural size. 



FIG. 10. Vertical section through a fruit-body when autodigestion is nearly 

 completed. The remains of the gills have now become horizontally outstretched. 

 Liquid drops may be seen at d in such a position that they do not interfere with 

 the liberation of the spores into the air. a, edge of gill where spore-liberation 

 and autodigestion are still in progress, m, marginal band on gill edge covered 

 with cystidia. Natural size. 



FIG. 11. Fruit-body in the last stage when spore-liberation has ceased. The 

 gills have now entirely disappeared. The central part of the pileus flesh still 

 crowns the stipe. Natural size. 



FIG. 12. Semi-diagrammatic drawing of part of a gill surface m the region of 

 autodigestion. There are five zones running parallel to the oblique gill edges : 

 (1) a-af, zone of basidiawith ripe spores. (2) b-b', zone of basidia discharging spores 

 into an interlamellar space. The spores are shot off their sterigmata successively, 

 so that in this zone some basidia have three spores left upon them, some two, and 

 some one, whilst some have lost them all. (3) c-c', zone of basidia which have dis- 

 charged all their spores. (4) d-d', zone of autodigestion. The basidia and para- 

 physes are becoming indistinct and gradually liquefied. (5) e-e', the dark liquid 

 film on the gill edge containing the products of autodigestion. Magnification, 

 320. 



PLATE III 



Figs. 13-17 all of C'oprinus comatus. 



FIG. 13. Surface view of part of one side of the inner swollen edge of a gill 

 before autodigestion has begun, m, marginal band covered with cystidia, c ; 

 h, hymenium containing basidia with ripe spores. Magnification, 1 20. 



FIG. 14. Transverse section through the inner swollen edges of three gills 

 before autodigestion has begun. The swollen edges contain large air-spaces, a a, 

 and are covered by cystidia, c. The spaces s s between the gills are lined by the 

 hymenium. The basidia each bear four spores; but of these, for the sake of 

 clearness, two only are shown. Magnification, 120. 



FIG. 15. Surface view of a piece of gill, O'Ol mm. by 0*02 mm., in 

 the region of ripe spores close to the zone of spore-discharge. Each basidium 

 bears four black spores, and is separated from its neighbours by paraphyses. 

 Magnification, 320. 



FIG. 16. Section through the hymenium in the region of spore-discharge. 

 The two uppermost basidia each bear four ripe spores ; the middle basidium has 

 discharged two spores, the next below that three spores, and the lowest basidium 

 of all four spores. Two sporabolic paths, one with the horizontal distance O'l mm. 

 long and the other with it 0'15 mm. long, are also shown. Magnification, 320. 



FIG. 17. Diagram showing the paths of spores during discharge from the gills. 

 A, transverse section cut horizontally through three gills. The dark, free edges 

 are covered by liquid films produced by autodigestion. The arrows show the 

 direction in which the spores are discharged from the zones of spore-discharge, 

 and also the distance to which they travel horizontally. B shows a piece of one 

 of the gills seen from the side. The arrows indicate by their positions and direc- 

 tions the vertical paths of the spores after leaving the zone of spore-discharge. 



