FOMES APPLANATUS 125 



formation, I think it best not to speak of chlamydospore formation 

 in Fames applanatus. 



Atkinson's statement x that what had been regarded as " the 

 truncate base " of a spore of F. applanatus is in reality the apex 

 has been confirmed by White's studies of the attachment of the 

 spores to their sterigmata in the living hymenium. 2 I have repeated 

 White's observations and found them to be correct. The spores of 

 Fomes applanatus, in being attached laterally by their pointed ends 

 to the sterigmata and in being, when ripe and dry, more or less 

 truncate at their distal ends, resemble the thick- walled spores of 

 certain Coprini and other chromosporous Agaricineae. The distal 

 end of the spore contains a germ-pore and is weaker than the rest 

 of the wall. Hence it collapses as the spore dries, and becomes 

 truncate. 3 The germ-tube always emerges through the germ-pore, 4 

 as during germination of the spores of Coprini. 



The Longevity of the Fruit-body. The fruit-body of Fomes 

 applanatus produces a new layer of tubes each year of its existence 

 (Fig. 44). In the spring, before a new layer of tubes is formed, 

 a thin brown tough horizontal layer of flesh or context is formed 

 by the ends of the old tubes, and from this the new tubes arise 

 (cf. Fig. 48). The new layer of flesh completely closes the ends of 

 the old layer of tubes above it, so that it is impossible for any layer 

 of tubes to function for more than one year. The average length 

 of life of a fruit-body, as determined by the number of its annual 

 tube-layers, is 4 or 5 years and its maximum length of life from 

 8 to 10 years. 5 I found a large fruit-body near Montreal which 

 protruded 9 inches from the stump on which it was situated and 

 possessed seven deep annual layers of tubes which, even in their dried 

 and shrunken condition, had a total depth of 4 inches. 



The Longevity of Various Polyporeae. Some other species of 

 Fomes, e.g. Fomes igniarius and.? 7 , officinalis, certainly often greatly 

 exceed Fomes applanatus in longevity. 



I have in my possession a fruit-body of Fomes igniarius, given 

 to me by Robert Hartig at Munich, in which 25 layers of tubes 



1 G. P. Atkinson, loc. cit. 2 J. H. White, loc. cit., p. 138. 



3 Ibid., p. 138. 4 Ibid., p. 144. 



5 J. H. White, loc. cit., p. 139. 



