COPRINUS MICACEUS 353 



suppose that the drop is carried away upon the spore. Of the 

 correctness of this view I was able to obtain conclusive evidence 

 in one instance. I watched a drop develop on the hilum of a spore 

 until its diameter became equal to one-half that of the spore. The 

 spore was then shot away and, as the hymenium was turned 

 upwards, it fell upon a neighbouring basidium. Immediately after it 

 settled, i.e. less than one second after its discharge, I noticed that 

 the drop was clinging to its upper side at one end. Very soon the 

 drop disappeared, doubtless either by flowing around the spore or 

 by evaporating. I have already recorded similar observations for 

 Coprinus sterquilinus and for Entoloma prunuloides.^ 



In Fig. 158, in the series of drawings of vertical sections of fruit- 

 bodies shown at A, B, C, D, and E, the ripening of the spores from 

 below upwards on the gills can be traced macroscopically by the 

 progressive darkening of the exposed gills from below upwards. 

 The darkening of the gills is due, in the main, to the development 

 of a brown pigment in the walls of the spores. 



During spore-discharge, if we exclude a consideration of the 

 cystidia, there are, just as in Coprinus sterqiiilinus and C. comatus, 

 five zones from above downwards at the free margin of each gill : 

 (1) a zone with perfectly ripe spores on the basidia, (2) a zone of 

 spore-discharge, (3) a spore-free zone, (4) a zone of autodigestion, 

 and (5) a zone along the very edge of the gill containing the 

 products of autodigestion. The first two of these zones have been 

 sufficiently dealt with. 



The spore-free zone, like the zone of spore-discharge, is relatively 

 larger than in most other Coprini. In one fruit-body I observed 

 with the microscope that it was • 1 mm. wide. However, it may 

 often be wider still, for in some fruit-bodies which had been placed 

 under a bell- jar I noticed that it could be seen as a fairly broad 

 light band with the naked eye. 



The zone of autodigestion is very narrow, as in other Coprini, 

 and it passes downwards into the gill-edge zone of the products of 

 autodigestion. Along the extreme edge of any gill which has been 

 shedding spores for some time there is a black line which, when 

 examined with the microscope, is found to be due to the presence 

 1 These Researches, vol. ii, 1922, pp. 14-15. 



VOL. III. 2 a 



