COPRINUS STERQUILINUS 241 



be readily observed through the horizontal tube of the microscope. 

 The magnification employed was 100 diameters. 



The lower edge of the piece of gUl, on being brought into focus, 

 could be seen very clearly, owing to its transparency, the large size 

 of the hymenial elements, and the contrast made by the black 

 spores against their white background. The zone of spore- 

 discharge presented the appearance shown in Fig. 104 between the 

 brackets h^ — h^ and 63 — \ \ and it was actively liberating its spores, 

 for spores could be seen raining down past the gill-edge. It was 

 observed that the four spores of each active basidium disappeared 

 from their sterigmata one after another in succession in the course 

 of about 1-5 minutes, as in other Hymenomycetes. 



On examining the zone of spore-discharge carefully, I dis- 

 covered that it was necessary to distinguish between (1) a higher 

 sub-zone (61—61 in Fig. 104, p. 242) in which the long basidia only were 

 discharging their spores and (2) a lower sub-zone (62—60) in which 

 the short basidia only were discharging their spores. In the latter 

 sub-zone, the long basidia no longer bore spores. It was observed 

 that, as the whole zone of spore-discharge gradually travelled up 

 the gUl, the two sub-zones kept the same relative distance apart. 

 If m Fig. 104, which embodies the results of the observations here 

 recorded, the sub-zone 6^ — by be carefully scrutinised, it will be noticed 

 that the long basidia are shedding their spores in succession from 

 below upwards ; for some of them have already lost one, two, or 

 even three of their spores, while the water-drops {w) on the hila 

 of some of the spores indicate by their presence that the spores 

 to which they are attached are within a few seconds of being dis- 

 charged. In the sub-zone 63 — h^ we have a repetition for the short 

 basidia of the phenomena of spore-discharge which have just 

 been described for the long basidia : the short basidia are shedding 

 their spores in succession from below upwards ; and water-drops 

 are appearing at the hila of spores which are about to be discharged. 



The direct observations on a living gUl which have just been 

 described prove beyond doubt that, in the general zone of spore- 

 discharge, the lo7ig basidia shoot away their spores just before the short 

 basidia below them. That the long basidia should thus take pre- 

 cedence over the short at the climax of their existence is a most 



VOL. III. 



