io8 RESEARCHES ON FUNGI 



autumnal development of tubes and its vernal production of spores, 

 is a striking exception to this rule and in this respect differs 

 from other well-known Fomes species, such as F. applanatus and 

 F. igniarius. F. applanatus (vide Chap. V for illustrations) certainly 

 has the normal mode of development, for I have observed that its 

 fruit-bodies produce a new layer of tubes in the spring and summer 

 and, when growing near the ground in secluded places, deposit 

 beneath themselves a thin brown layer of spores in the late summer 

 and early autumn (August and September). White's more detailed 

 observations on the spore-discharge period of this fungus will be 

 described and discussed in the next Chapter. We shall concern 

 ourselves with the summer spore-discharge period of F. igniarius 

 in another Section. It is not unlikely that some other species of 

 Fomes resemble F. fomentarius in vernal spore-production ; but, 

 for the present, they await discovery. 



Perennial Spore-production by One and the Same Tube-layer 

 in Fomes fomentarius. Another remarkable discovery made by 

 FauU in his investigation of Fomes fomentarius is that in this species 

 each annual hymenial tube-layer may produce a crop of spores for 

 four years in succession. 1 Hitherto, it has been tacitly assumed that 

 a layer of hymenial tubes in any species of Fomes functions for 

 one year and for one year only ; but now, so far as Fomes fomen- 

 tarius is concerned, this old assumption has been found by Faull to 

 be without justification. Let us suppose that in the spring of 1924 

 we have before us a fruit-body of F. fomentarius five years old, which 

 produced annual tube-layers in the summers of 1920, 1921, 1922, 

 and 1923. Then, assuming the correctness of Faull's observations, 

 with the advent of the spore-discharge period, we should find that 

 spores were being liberated not only from the tube-layer produced 

 in 1923 but also from the tube-layers produced in 1922, 1921, and 

 1920. Moreover, if from 1920 to 1924 we could have investigated 

 the tube-layer produced in the summer of 1920, we should have 

 found that it would have produced and liberated spores not only in 



1 J. H. Faull, " Further Observations on the True Tinder Fungus," a paper 

 communicated to a joint meeting of the Mycological Section of the American Bot. 

 Soc. and the American Phytopath. Soc., held at Toronto, December, 1921, under 

 the auspices of the American Ass. for the Adv. of Science. Cited from the abstract. 



