Bui. 247, U. S. Dept. of Agriculture. 



Plate I. 



^ECIOSPORES OF CRONARTIUM PYRIFORME AND A "I WIG OF PlNUS CONTORTA. 



Fig. 1. — iEciospores of Cronartium pyriforme, from, the type specimen on Pinus sp. at Albany, 

 N. Y. (Microphotograpli.) Fig. 2.— ^Eciospores of Cronartium pyriforme from Pinus pun- 

 gens, collected near Greenwood Furnace, Pa. (Microphotograpli.) These closely resemble 

 the type. Fig. 3. — iEciospores of Cronartium pyriforme from Pinus contorta, near Eldorado 

 Springs, Colo., from the same tree as the type of Peridermium betheli (microphotograpli), 

 showing the variation in the shape of the spores on this pine from those of the type 

 specimen in figure 1. Fig. 4.— A twig of Pinus contorta, showing the secia and peridia of 

 the fungus Peridermium pyriforme (P. betheli) on a slightly swollen portion. (About natural 



