Bui. 247, U. S. Dept. of Agriculture. 
Plate I. 
/Cciospores of Cronartium pyriforme and a Twig, of Pinus contorta. 
Fig. 1.— JEciospores of Cronartium pyriforme, from the type specimen on Pinus sp. at Albany, 
N. Y. (Microphotograph.) Fig. 2.— iEciospores of Cronartium pyriforme from Pinus pun- 
gens, collected near Greenwood Furnace, Pa. (Microphotograph.) 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 (microphotograph), 
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 
size.) 
