4 IXTKODUCTION 



more wilhiu a few hours, unci conlinues for d;iys or weeks. It was 

 therefore possible for mo to collect a stock of these fruit-bodies in 

 autumn, to revive them at will, and thus to study the liberation of 

 spores throughout winter and spring. 



There seems to be but little literature dealing with the liberation 

 of spores of Hymenomycetes. Some observations of Brcfeld,^ given 

 in a footnote in his description of the life-history of Coprinus ster- 

 corarius, Avill be mentioned and criticised later on. Richard Falck - 

 has published a paper on the scattering of spores of Basidiomycetes, 

 in Avhich he has given an account of the gradual accumulation of 

 spore-deposits on upper surfaces in closed chambers. He did not 

 succeed in actually seeing the spores in the air, but his experiments 

 showed that they are carried Avith remarkable ease by the slightest 

 air-currents. This fact can be verified directly and very simply by 

 means of my beam-of-light method, and rendered capable of mathe- 

 matical treatment by an exact determination of the rates of fall of 

 the spores in still air. 



A visible spore-discharge from a fruit-body has been occasionally 

 observed as a very rare phenomenon by a few botanists. To the 

 records of Hoffman, H. von Schrenk, and Hammer^ will be added 

 m}^ own upon the visible discharge of spores from fruit-bodies of 

 Polyporiv^ squa mosus. 



In his translation of Pfeff'er's rhysiulofjii of Flant^, EAvart-* added 

 a brief statement of some of my then unpublished conclusions con- 

 cerning the liberation and fall of spores. The evidence in support 

 of these conclusions is brought forward for the first time in this 

 book. 



In an account of the biology of Pal ij par an i^qaainosiis, I recorded 

 a number of observations upon the fall of spores in that species, and 

 gave an illustration showing the paths taken by the spores in falling 

 down the hymenial tubes.^ A subsequent calculation, however, 



' Brefeld, Jlotanisrhe Untersuchuyujen iiher Schimmcli)ib:e, III. Heft, pp. 65, GO. 



^ R. Falck, "Die Sporenverbreitmif; bei den Basidiomyceteii," Ikitnige :.>ir 

 Biologic dvr I'JianM,, 13d. IX., Heft 1, 1904. 



^ For references, rirfe I'w/ra, Chap. \'I. 



* Pfetter, I'hij.'iioloijy of J'Uuits, translated by A. J. Ewart, vol. iii. 1900, p. 410. 



^ Bulier, "The Biolofjy of Paliqjorns .s(iuariwsii.<, Huds., a Timber-destmyinf^ 

 Fungus," The Journal of Economic llioloyy, vol. i., 1906, p. 131. 



