244 RESEARCHES ON FUNGI 



basidium w in the sub-zone h^ will discharge all its spores before the 

 short basidium r immediately below it shoots away its first spore. 

 On the right-hand side of the figure, the numbers 1 to 7 contained 

 within the brackets b and a and opposite the basidia indicate the 

 order in which the basidia will discharge their spores. A study of 

 this order will show the reader how systematically the spores of the 

 long basidia are removed before the time comes for the discharge 

 of the spores of the immediately neighbouring short basidia. Water- 

 drops are represented as being excreted from the hila of certain 

 spores of the basidia v and w on the left-hand side of the figure and 

 of the basidia No. 2 and No. 3 on the right-hand side. The scale 

 shows that the zone of spore-discharge is only 0-2 to 0-3 mm, 

 from the extreme edge of the gill. 



When observing the edge of the hanging gill in the compressor 

 cell with the horizontal microscope, I selected certain groups of 

 basidia for especial study. In one such group, situated just above 

 the approaching zone of spore-discharge (c/. Fig. 104, zone a, p. 242), 

 a central long basidium was projecting beyond, and surrounded 

 by, four short basidia, two above and two below. The arrange- 

 ment of these five basidia is shown diagrammatically in the first 

 column of the subjacent Table. For convenience, the central 

 long basidium will be referred to as A, the two lower short basidia 

 as B and C, and the two upper short basidia as D and E respec- 

 tively. The five basidia soon became involved in the upward- 

 moving zone of spore-discharge, and I succeeded in observing the 

 successful discharge of all the twenty spores belonging to them. 

 The moment of discharge of each spore was carefully noted. I 

 called out as each spore was shot away, and my assistant, Mr. S. G. 

 Churchward, recorded the times in seconds by his watch. If the 

 time of discharge of the first spore on each basidium be taken as 

 the zero of a time-scale and the times of discharge of the other three 

 spores be reckoned from it, then the Table on p. 245 shows the times 

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



From the data there given it will be seen that each of the five 

 basidia shot away its four spores in less than a minute and a half 

 after the first spore had been shot away, and that the mean time 

 occupied in discharging the four spores was just over one minute. 



