SPORE-DISCHARGE FROM POLYPOREAE 109 



the spring of 1921, but also in the spring of the years 1922, 1923, 

 and 1924. This is an entirely new conception of hymenial activity 

 in the Polyporeae and affords further evidence of the high efficiency 



FIG. 37. A fruit-body of Fomesfomentarius, probably six years old, attached 

 to the trunk of a Birch, Betula lutea. Obtained in Algonkiii Park, 

 Ontario, Canada. Photographed by J. H. Faull. About natural 



size. 



of Fomes fruit-bodies as organs for the production and liberation 

 of spores. It will be of interest to learn whether in a hymenial 

 tube of a tube-layer which has functioned for four years four new 

 hymenial layers are formed one above the other, thus slightly 



