XXI 
aph of 
Ep 
Betula lutea 
AT: 
Pi 
ion of 
sect 
se 
20 
ver 
xX 
trans 
wood, 
a 
) 
( 
icrogr 
Photomi 
yellow birch 
. 2.— Photomicrograph 
Rieee 
normal 
section of 
yporus 
s 
erse 
ed by Pol 
nsv 
¥ 
a 
OL abe 
wood deca 
) 
Betula lutea 
De 
3 
h ( 
x 
ire 
pargamenus, 
Fig 
yellow b 
x 
