142 RESEARCHES ON FUNGI 



spores came suddenly iuto view at a distance of 0-1 -0-2 mm. from 

 the gills. As soon as seen, the spores were falling vertically at a 

 constant speed.^ The diagram, Fig. o], shows the courses of a few 

 spores as seen with the horizontal microscope. These observations 

 seem to me to afford conclusive proof of violent spore-projection. 

 They ma}^ be repeated without difficulty. One may have to wait 

 a few seconds or minutes before a spore springs into view, but this 

 is merely a question of patience. The species used for these ob- 

 servations, in addition to Ainanitopsis vaginata, were : Psalliota 

 campestris, Marasiniibs oreades, and Polyporus squamosus. For 

 the Polyporus a piece of the wall between two hymenial tubes 

 took the place of a piece of gill. 



The horizontal distance from the hymenium, at which a spore, 

 Avhen first perceived, appeared to be, was compared with the dis- 

 tance between tiny irregularities on a silk thread of the Ramsden 

 eyepiece of the horizontal microscope. The latter distance was 

 then carefully measured with a standard micrometer scale. After 

 a number of observations had been made in each case, the con- 

 clusion was arrived at that the spores of Ainanitopsis vaginata 

 are often shot to a horizontal distance of 4 mm., and that those 

 of the other three species are often shot y\f mm. and sometimes 

 a little further. 



Method III. — The third method employed for demonstrating 

 the violent projection of spores from the sterigmata is perhaps 

 the most conclusive of all. It can be carried out most certainly 

 and easily with fruit-bodies of the Coprini. Coprinus plicatilis 

 was made chief use of in these experiments, but C. comatus 

 and C. niicaceus gave similar results. One takes a gill that 

 is shedding spores and lays it Hat in a closed compressor cell, and 

 observes it from above with the low power of an ordinary micro- 

 scope. Under these conditions the basidia are pointing ujawards. 

 One can then very readily observe the disappearance of the spores 

 from the sterigmata near the " deliquescing " gill edge, for it is 

 here and here alone in the Coprini that active discharge of spores 

 takes place (Plate II., Fig. 12). If one focusses a plane at a little 



^ The air in a compressor cull is practically quitu still. The spores fall verti- 

 cally in it, and are not carried about by convection currents. 



