WHITE-PINE BLISTER RUST IN WESTERN EUROPE. 21 
trol which they have apphed to small groups or isolated ornamental 
specimens. Strenuous efforts to control the blister rust wherever it 
occurs are not made in Europe because the tree lacks the commercial 
status necessary to warrant such action. 
No European country has carried out a definite scheme of study 
for the control of Cronartium ribicola covering a number of years. 
The work done in the past has been conducted by individual initia- 
tive and interest, the investigators working independently and in 
some cases apparently unaware of each other’s activities. The work 
in Sweden by Eriksson was prompted by a popular fear lest the 
disease on Pinus strobus should prove a menace to the native Pznus 
sylvestris, the principal forest timber species. 
GERMANY. 
Klebahn’s work in Germany was undertaken from a purely sci- 
entific viewpoint. He paid little attention to the practical side of the 
question when he saw 
that the foresters were 
not concerned about 
it. When the United 
States restricted the 
entry of five-needle 
pine nursery stock in 
1912 because of the 
fungus, the nursery- 
men took a greater in- 
terest in the subject. 
Large nurseries situ- 
ated near Halsten- 
beck, Germany, con- 
ducting an extensive 
export trade were par- 
ticularly affected by Fic. 11—A large forest-tree nursery in France. The seed 
: an v beds, started since the war, contain Austrian pine, Scotch 
this restriction. They pine, and Norway spruce. 
called upon Klebahn 
to witness that their stock was free from blister rust, which testimony 
he was bound to decline, since the fungus is difficult to detect on seed- 
lings. To Klebahn’s knowledge measures against the disease have 
not been taken anywhere in Germany, since Pinus strobus, aside 
from the nurserymen’s point of view, is of small economic im- 
portance. It is said that in the municipal forest of Heidelberg there 
are mature white-pine plantations covering nearly 150 acres. This 
is probably the largest single plantation of the species in Europe. 
Professor von Tubeuf, who has made a careful study of the blister 
rust in Germany, expects that in the future white pine will be grown 
less and less in that country.” : 
SIGNIFICANCE OF EUROPEAN EXPERIENCE TO AMERICA. 
The observations made abroad on the susceptibility of sugar pine, 
western white pine, and the limber pine show that these species are 
as readily attacked and as severely damaged by the white-pine blister 
rust as is the eastern white pine. Laurie found western white pine 
#2 Correspondence with Professor von Tubeuf, 1920, 
