COPRINUS STERQUILINUS 239 



broader, radial, spore-filled areas (uniformly coloured if the spores 

 are coloured) corresponding to the interlamellar spaces in their 

 entirety. The difference between the appearance of an inaequi- 

 hymeniiferous spore-deposit and an aequi-hymeniiferous one, may 

 be at once realised by comparing Fig. 102, which shows a spore- 

 deposit for Coprinus sterquilinus, with Fig. 141 in Volume II 

 (p. 402), which shows a spore-deposit for Psalliota campestris. 



The five zones which can be distinguished near any gill-edge 

 from which spores are being liberated are illustrated with a magni- 

 fication of 300 diameters in Figs. 104 and 105 (pp. 242 and 249), and 

 they will now be described in detail. 



(a) The zone of the hasidia with ripe spores. This zone has been 

 fully described already in the Section dealing with The Structure 

 and Development of the Hymenimn. As we have seen, it is composed 

 of long and short basidia and of paraphyses, so arranged as to form 

 a beautifully efficient hymenial mosaic-work. All these elements 

 are clearly shown in the zone a in Figs. 104 and 105. The spores 

 of the long and the short basidia are equal in size and quite black, 

 but in Fig. 104 the spores of the long basidia have been shaded more 

 deeply than those of the short basidia for the purpose of giving a 

 correct perspective : the former are at a higher plane than the 

 latter and therefore stand nearer to the reader. The long basidia 

 are almost as numerous as the short ones, and the spores of the 

 former often stand in part vertically over the spores of the latter. 



(b) The zone of spore-discharge. We have seen that, when the 

 mature hymenium is about to shed spores, the basidia are crowded 

 together in such a way that the spores of the long basidia often stand 

 in part vertically over some of the spores of the short basidia. If, 

 in the zone of spore-discharge, the spores of the short basidia were 

 to be shot off before, or at the same time as, the spores of the neigh- 

 bouring long basidia, it is obvious that the former would often 

 collide with the latter and on this account be prevented from freely 

 escaping from the fruit-body. Such collisions, however, are pre- 

 vented owing to the fact that the long basidia shoot away their 

 spores just before the short ones which are immediately below them. 

 The zone of spore-discharge is always composed of two sub-zones : 

 (1) an upper zone, b^ in Figs. 104 and 105 (pp. 242 and 249), in which 



