PLATE VIH 



Fig. I. — Qucrciis alba: Crescent-shaped "soak," the initial stage of the piped rot 

 produced by Polyporus dryophilus; from Arkansas. 



Fig. 2. — Quercus alba: A radial view of the rot in a limb, showing delignification; 

 from Arkansas. 



Fig. 3. — Qticrcus oblongifolia: A radial view of rot, showing delignification; from 

 Arizona. 



Fig. 4. — Quercus alba: A final stage of the rot, radial view, with more complete 

 delignification; from Arkansas. 



Fig. 5. — Quercus alba: A tangential view of the rot, showing delignification in 

 pockets; from Arkansas. 



Fig. 6. — Quercus alba: An end view showing a cross section from the same tree as 

 the preceding; from Arkansas. 



Fig. 7. — Quercus sp.: A section of oak from Von Tubeuf, sent to the junior writer 

 as a specimen of the rot caused by Polyporus dryadeus in Europe. 



Fig. 8. — Quercus sp. : The reverse side of tlie specimen sho«-n in the preceding. 



Fig. 9. — Quercus sp. : A section of oak from Europe, obtained by Von Schrenk, with 

 a piped rot similar to that of Polyporus dryophilus. 



(78) 



