WHITE-PINE BLISTER RUST IN WESTERN EUROPE. eB) 
| by correspondence from other European countries, including Ger- 
many, Switzerland, Holland, and Russia, although these countries 
_were not actually visited. 
HISTORICAL REVIEW. 
Both the Peridermium and Cronartium forms of Cronartium 
vibicola have been known in Europe for 65 years. Dietrich first 
used the name about 1856 in a collection of dried plants entitled 
“Plantarum Florae Balticae Cryptogamarum” (//, p. 287), and 
European writers generally attribute the name to him. Five years 
later, in 1861, W. Saellen discovered the fungus on white pine. near 
Helsingfors, Finland. The form on Ribes, as far as is known, was 
not found in that country until 1897 (25, p. 447-449). Rostrup, in 
1865, found the disease in Denmark on black currants, while Kor- 
nicke first found it in East Prussia in 1865 (27, p. 281). It was 
unknown in the rest of Germany until Fischer de Waldheim found 
it on Ribes aureum at Stralsund in 1871.2 The following year 
Magnus found it on the same species at Kiel (29). 
The disease was reported on one or both hosts from western Si- 
beria in 1879,? Sweden in 1880 (14), Norway in 1885 (7, p. 70), 
Holland in 1885 (32, p. 239), France in 1889,* and during the fol- 
lowing decades from the British Isles in 1892 (33), Belgium in 
1894 (31), and Switzerland in 1895 (/5). The date 1887 is perhaps 
the most significant in blister-rust history, for in that year Klebahn 
separated the old composite species Peridermium pini Willd. into 
three species, namely, Peridermium pini ribicola Kleb., Peridermium 
cornui Rostrup and Klebahn, and Peridermiwm strobi Kleb. (23). 
In 1888 Klebahn determined by inoculation experiments the re- 
lationship between the Peridermium form on Pinus strobus and the 
Cronartium form on Ribes. The same year, in company with O. 
Nordstedt at Grimstorp, Westgotland, Sweden, this belief was veri- 
_ fied when they found white pine and black currants growing close 
_ together and both badly diseased (22). 
Following the determination of the host plants the fungus has 
been repeatedly found and reported from several European coun- 
_ tries, attracting the attention of both mycologists and foresters. Its 
distribution covers nearly the whole of western Europe and the 
British Isles and, according to statements by members of the Nor- 
wegian forest service, extends to 634° north latitude on the Nor- ° 
wegian coast. The date of the introduction of the blister rust into 
America is not known, but circumstantial evidence indicates that it 
was first introduced from Europe about 1898. 
SUSCEPTIBILITY OF BLISTER-RUST HOSTS. 
FIVE-NEEDLE PINES. 
The current European opinion is that the fungus originated on 
Pinus cembra in Siberia, migrated to Europe, and became far more 
virulent on the exotic five-leaved pines than on its supposed original 
host. Contrary to the writer’s expectations, he found no Pinus 
2Rabenhorst, L. Fungi europaei exsicatti, No. 1595. 
’ Thuemen, Felix von. Mycotheca universalis, No. 2049. 
*Specimen. Natural History Museum, Paris. 
