ioo RESEARCHES ON FUNGI 



became deflected into a new path, and the spores became scattered 

 fairly regularly. In quite still air in very small chambers, Coprinus 

 spores fall quite vertically. 1 These observations seem to me to 

 warrant the belief that the localised and irregular spore-deposit 

 formed by the Coprinus in the first instance was due to convection 

 currents which kept circulating in a constant path, thereby deflecting 

 the rapidly falling stream of spores out of the vertical toward one 

 side of the jar. It is scarcely necessary to discuss how regular 

 convection currents might arise in the closed system which was 

 employed, but it may be pointed out that the living and actively 

 respiring Coprinus pileus might well be responsible for them. 



Falck arranged tiers of circular paper discs, one above the other, 

 in a tall cylindrical glass chamber where a pileus was liberating 

 its spores. Under these conditions he often obtained very curious 

 radiating spore-deposits on each disc. Here, again, the assumption 

 that convection currents taking regular paths existed in the 

 chamber, seems to me quite sufficient to give a basis for an ex- 

 planation of the results. As one may readily observe by means 

 of the beam-of-light method, the spores are carried away from 

 the underside of the pileus in the form of a comparatively thin, 

 dense, and continuous stream. The stream which reveals the 

 presence of convection currents, doubtless, would be carried along 

 slowly, first over one surface, then over another, dividing here 

 owing to this obstacle, and turning back there owing to another, 

 until finally it would be broken up. Where on any surface a 

 dense trail of spores has accumulated, it may be assumed that 

 the spore stream took a regular path just above. If the convection 

 currents are only fairly constant in their directions, then owing to 

 the fact that the spores in the first instance are swept away from 

 the pileus in the form of a stream, fantastic spore-patterns seem to 

 be just what should be expected under the conditions provided 

 by Falck's experiments. 



In concluding my remarks in this chapter, I wish to recommend 



the demonstration of spore-fall by the beam-of-light method to 



all those who give lectures or laboratory courses which include a 



treatment of the fruit-bodies of Hymenomycetes. It is difficult 



1 Vide infra, Chap. XV. 



