Visibility of spore dissemination. R. E. Stone. 293 



(11) Reed, G. M. — Infection experiments with Erysiphe 



graminis DC. (Trans. Wise. Acad. Vol. xv. Part I.) 



(12) Searle, G. O. — The Comparative SusceptibiHty of varieties 



of Swedes and Turnips to the " Swede Mildew " [Erysiphe 

 Polygoni DC). (Rept. Econ. Mycol. South-Eastern Agric. 

 Coll. 1913-1914.) 



UPON THE VISIBILITY OF SPORE DISSEMI- 

 NATION IN FOMES PINICOLA 

 (SWARTZ.) FR. 



By R. E. Stone, Ph.D. 



(Department of Botany, Ontario Agricultural College.) 



The larger fungi liberate millions of spores and yet the dis- 

 semination of the spores has not often been directly seen. 

 Buller* has observed this phenomenon probably in more species 

 than any one else, and he has devised a number of methods for 

 detecting it. With the naked eye he saw spore clouds leaving 

 the under surface of a fruit-body of Polyporiis sqiiamosus for 

 thirteen days in succession f. The following observations were 

 made by myself upon a fruit-body of Fomes pinicola in a wood 

 near Guelph, Ontario, and I am recording them at Professor 

 Buller's suggestion. 



In May, 1917, I was collecting fungi in a dense poplar and 

 white spruce swamp. Having become tired I sat down on a 

 fence a short distance from a large stump from which was pro- 

 truding a fruit-body of Fomes pinicola. The fungus was directly 

 between myself and the sun and it was brightly illuminated by 

 rays of light penetrating through the dense foliage. I distinctly 

 saw clouds of spores streaming from the under side of the fruit- 

 body and drifting away in the very slight air currents that were 

 moving between the trees. 



* A. H. R. Buller, Researches on Fungi. London, 1909, pp. 89-101, 133-147. 

 f Ibid. p. 90. 



