50 



RESEARCHES ON FUNGI 



The discharge of the spores of Coprinus plicatilis takes place, 

 as in C. comatus, G. atramentarius, and all other Coprini, on each 

 gill from below upwards (Fig. 34). This fact can be made out both 

 macroscopically and microscopically. In the field one can observe 

 that, durmg the spore-discharge period, the gills become lighter 

 from below upwards, or, from the point of view of the pileus as a 

 whole, centripetally ; and, if one examines a whitening gill with 

 the microscope, one finds that all the basidia in its upper darker 

 part still bear spores on their sterigmata, that all the basidia in its 



lower fighter part have 

 shed their spores, and that 

 between the darker and the 

 lighter parts there is an 

 intermediate zone of spore- 

 discharge where the basidia 



Fm. 33.-Coprinus plicatilis. Vertical sections ^rc engaged in shooting 



showing four stages in the development of a away their sporeS. This 



young and unexpanded fruit-body, drawn j- i 



semi-diagrammatically, to illustrate the ZOUC OI Spore-dlSCharge, 



ripening of the spores from below upwards r^- i^ fravpk slowlv toward 



on the gills. A, spores on gills developing but WUlCU travels SiOWiy towaru 



as yet colourless, so that gills are white. ^ B ^\yQ (Jjg^ of the pileUS, in 



general resembles that of 

 other Coprini, e.g. C. coma- 

 tus and C. atramentarius, 

 but it is somewhat broader 

 than usual. Doubtless, although the point has not yet been verified 

 by actual observation, where the basidia are trimorphic the zone 

 of spore-discharge consists of three sub-zones : an upper, in which 

 only the longest basidia are dischargmg their spores ; an inter- 

 mediate, in which only the basidia of intermediate size are dis- 

 charging their spores ; and a lower, in which only the shortest 

 basidia are dischargmg their spores. In most Coprini, e.g. C. 

 comatus, C. sterquilinus, C. atramentarius, C. lagopus, and C. curtus, 

 the basidia are strictly dimorphic and the zone of spore-discharge 

 consists of two sub-zones only ; but in G. micaceus the basidia are 

 quadrimorphic, and the zone of spore-discharge consists of as many 

 as four sub-zones. In havmg trimorphic basidia and three sub- 

 zones in the zone of spore-discharge, G. plicatilis and G. niveus 



and C, spores on gills ripening from below 

 upwards and thus turning the gills black 

 from below upwards. D, the spores have 

 now all developed their pigment, so that 

 the gills have become completely blackened. 

 Enlarged to 1 • 33 the natural size. 



