COPRINUS PLICATILIS 



53 



down on a slide, and observed the discharge of the spores with the 

 low power of the microscope. Mr. W. B. Grove examined one of 

 the pilei in the same manner and kindly observed the times of 

 discharge of all the four spores of each of five basidia. If the time 

 of discharge of the first spore of each basidium be taken as the zero 

 of the time-scale and the times of discharge of the other three spores 

 be reckoned from it, then the accompanying Table shows the times 

 of discharge for all the four spores of each of the five basidia. 



The Rate of Discharge of the Fovr Spores for each of Five Basidia of 



Coprinus plicatilis 



From the Table it will be seen that, when once a basidium had 

 begun to shoot away its spores, on the average the last of its spores 

 was discharged within 1 1 seconds of the first. In Coprinus sterqui- 

 linus, by observations made on five basidia, it was determined that 

 on the average the last of the four spores was discharged within 

 68 seconds of the first. ^ The interval of time observed between 

 first and last discharges in C. jjlicatilis, therefore, was only one- 

 sixth of that observed in C. sferquilinus. 



Coprinus plicatilis was one of the first Hymenomycetes w^hich I 

 examined when attempting to determine whether or not spores are 

 violently discharged from their basidia. A gill was placed flat in 

 a closed compressor cell, so that the hymenium looked upwards. 

 A plane in the air about • 1 mm. above the plane in which the spores 

 were disjjosed was focussed with the microscope. When the dis- 

 charge of the spores was taking place, many spores came momentarily 

 ' These Eesearches, vol. iii, 1924, p. 245. 



