196 Report oF THE BoranicAL DEPARTMENT OF THE 
into a new country has become more virulent in its attack and 
caused greater damage than in its native country. 
There is also the possibility that it may extend its list of host 
plants. In Europe it is known to attack only four species of 
Pinus ;°4 viz., P. strobus, P. cembra, P. lambertiana and P. monti- 
cola, all of which bear their leaves in clusters of five. 
TREATMENT. 
Since it is probable that pine trees and Ribes plants are both 
necessary to the perpetuation of the Cronartium, the destruction of 
all specimens of either of these two kinds of host must result in the 
extermination of the rust. Accordingly, the principal method of 
control recommended by European writers is the destruction of 
whichever of the two hosts is the least valuable. Wherever there 
is danger of the disease, currants or gooseberries should not be 
planted near white pines. 
It is possible that on currants and gooseberries the rust might 
be controlled by spraying with bordeaux mixture, but no experi- 
ments have been made. On the Station grounds one application 
of bordeaux mixture made as soon as the fruit had set apparently 
had no effect on the rust. 
BIBLIOGRAPHY OF CRONARTIUM RIBICOLA AND 
PERIDERMIUM STROBI. 
With the appearance of Cronartium ribicola in this country there 
is likely to come renewed interest in it. In order to facilitate the 
labors of American mycologists who wish to examine the literature 
of the subject, the following bibliography has been compiled. It is 
not quite complete and several of the articles have not been seen 
by the writer. By far the most important of the references given is 
Klebahn’s book, Die wirtwechselnden Rostpilze, which contains an 
authoritative resumé of the whole subject with numerous citations 
of literature. 
1. Anonymous. Cronartium ribicola Fischer, nov. sp. Hedwigia, 11:182. 
1872. 

2. Weymouth Pine Disease. Gard. Chron., III., 11:736. 1802. 
“3. de Bary, Ay Bot, Ziz. 3rtasT. 167s 
*Klebahn (34). 
