28o RESEARCHES ON FUNGI 



(1) the four spores of each basidium are violently propelled more 

 or less perpendicularly outwards from the hymenium into the 

 adjacent interlamellar space ; (2) they leave the sterigmata one by 

 one and are not all discharged together ; and (3) the time elapsing 

 between the shooting away of the first and last of the four spores 

 of a basidium is usually from one to ten minutes. The discharges can 

 be observed without difficulty if one lays a piece of a gill like that 

 shown in Fig. 120 in a closed compressor cell and looks down upon it 



\v^ 





Fig. 119. — Coprinus atramentarius. An expanded fruit-body in an 

 advanced state of autodigestion, shedding spores. The gills 

 have become reduced to about one-seventh of their original 

 size. Photographed at Winnipeg. Natural size. 



from above with the microscope.^ The spores can then be seen 

 leaving the basidia in the zone of spore-discharge. Some of the 

 basidia will be found to have four spores upon them, some three, 

 some two, some one, and some none at all. 



Just before the spore is to be discharged, a small drop of water is 

 excreted from the hilum of the subjacent sterigma, as in all other 

 Hymenomycetes (Fig. 120, h, i). The time which elapses from the 

 beginning of the excretion of each drop to the discharge of the spore 

 which carries it away has a duration of from 5 to 10 seconds. 

 Normally in Hymenomycetes, and I believe in Coprinus atramen- 

 tarius, when a spore has been shot away, the end of the sterigma 



^ The compressor cell is employed to protect the gill from too rapid loss of 

 moisture. 



