FOMES APPLANATUS 



129 



(Fig. 49). The mode of attachment and the mechanical rigidity of 

 the fruit-body as a whole are therefore important factors in bringing 

 about the successful liberation of the spores. 1 



FIG. 46. Fames officinalis. A fruit-body with 5-6 layers of hymenial 

 tubes, and therefore 5-6 years old, growing upon the trunk of 

 Paeudotsuga taxifolia in Montana. Photograph supplied by G. G. 

 Hedgcock of the U.S.A. Department of Agriculture. About \ 

 natural size. The width of the fruit-body was 7 inches. 



The hymenial tubes are not only often upwards of 1 cm. in 

 length and less than 0-2 mm. in diameter, i.e.. very long and narrow, 



1 Cf. vol. i, 1909, pp. 39-40. 



