6 
BULLETIN 957, U. S. DEPARTMENT OF AGRICULTURE. 
To sum up briefly: Pinus cembra, the probable original pine host, 
ranges across northern Asia; and the fungus is reported from western 
eastern, and central Asia, in some places where it may easily be 
endemic. 
In North America, Cronartium ribicola was first found in 1906 at 
Geneva, N. Y. (3, 150). Later findings have indicated that it was 
here in the Northeastern States as early as 1898 (108, 136, p. 6). It 
might have been in North America a few years, but not many, before 
that date. This is supported by Clinton (13), who unsuccessfully ex- 
amined specimens of Ribes which are in some of the larger herbaria 
of the eastern part of this country. The writer has supplemented 
Fig. 3.— Outline map of the northeastern part of the United States, showing (by black dots) the known 
distribution of white-pine blister rust in North America to and including 1909. 
Clinton's work by examining the Ribes specimens in several addi- 
tional herbaria. These include the Pringle herbarium at the Uni- 
versity of Vermont and the local collections of the University of 
Vermont; of Dartmouth College; of President Ezra Brainerd, of 
Middlebury College; of Mr. C. A. Weatherby, of East Hartford, 
Conn.; and of Mr. C. H. Bissell, of Southington, Conn. The most 
notable herbarium examined was that of the Boston Society of 
Natural History, which contains many New England collections 
made in the early years of the nineteenth century. Moreover, such 
keen fungus collectors as Farlow, Seymour, G. P. Clinton, Peck, 
Ellis, George Clinton, Stewart, and many others, never collected 
Cronartium ribicola until 1906, showing that it is a recent immi- 
grant. Since 1909, when it was first found in North America on 
white pines, Cronartium ribicola has spread until it is firmly estab- 
