PLATE XXVII. 
he last portion of the sapwood of a pignut hickory (Hicoria glabra) log to 
ecomposed by the action of Polyporus pargamenus, the remainder of the 
ood having been completely decayed. The completely disintegrated wood 
ering to these comparatively sound pieces was removed by rubbing and scrap- 
Note the black color of the superficial portions of these pieces of undecayed 
d. It was caused by the infitration of abundant decomposition products into 
se portions immediately adjoining the completely decayed wood. ‘The central 
@ (marked X) shows one of these pieces in transverse section. 
