Dec 1, 1924 
Diagnosis of Decay in Wood 533 
Fig. 2A .—Transverse section of Pinas ponderosa infected with P. anceps (P. ellisianus). Typical 
grayish-white pocket rot at a and similarly shaded isolated areas. Red-brown incipient rot at b. At 
c a faint yellow-brown invasion zone which appears only in part of the infected wood. Note the radiate 
development of the rot. One-fifth natural size. B.—Transverse section of Tsuga heterophylla infected 
with Echinodontium tinctorium. Typical brown stringy rot at a, typical rot not stringy in texture 
at b, typical rot grading into incipient rot at c. A very faint discoloration extending from incipient 
area at edge of c up to sapwood zone at dotted line. Dead branch stub at d and unhealed frost crack at 
e. One-sixteenth natural size. C.—Transverse section of Acer rubrum infected with Fomes igniarius. 
Typical rot in central shaded area surrounded by the darker band of the invasion zone. One-sixteenth 
natural size. D.—Transverse section of Tilia arnericana infected with Pholiota adiposa. Typical rot 
in central shaded area surrounded by the darker band of the invasion zone. Note the earlier invasion 
zones still showing and included within the typical rot area. One-sixteenth natural size. E.—Trans¬ 
verse section of Tsuga canadensis infected with Fomes pinicola. Typical brown cubical rot at a. Faint 
yellowish-brown discolored areas of incipient rot at b. One-sixteenth natural size. 
