PLATE XXVII 



Fig. I. — Peridermium pyriforme (F. P. 18044) ^^ ^ trunk of Pinus divaricata, showing 

 the form of the peridia before they are ruptured to allow the escape of the seciospores. 



Fig. 2. — A globose gall with Peridermium pyriforine on a trunk of Pinus contorta 

 (F. P. 19437), associated with two lesions of Peridermium comptoniae, one near the 

 gall and the other i inch above it at the base of a branch. 



Fig. 3. — Peridermium pyriforme (F. P. 19429) on a branch of Pinus arizonica showing 

 unopened peridia. This branch was i inch in diameter and 10 years old. 



