WHITE-PINE BLISTER RUST. 3 



data, especially toward that appearing in the chapter on control, Table 

 V, and the list of Ribes species infected in the different States. Much 

 difRculty has been encountered in getting satisfactory translations 

 of articles published in the Japanese, Russian, Dutch, Swedish, Nor- 

 wegian, and Danish languages. Dr. E. P. Meinecke has very kindly 

 translated most of the Scandinavian and Danish articles. Mr. Rush 

 P. Marshall and Miss M. W. Taylor, have aided in checking and col- 

 lating the extensive data here presented. 



In this bulletin the behavior of Cronartium rihicola is given with 

 considerable detail. So far as is now known, it agrees essentially 

 with the Uredinales in general in its life history and physiology. 

 This is the first species of Cronartium to be very intensively investi- 

 gated, and as a representative of this important group of forest-tree 

 fungi, a detailed knowledge of its life history must form the basis 

 for the institution of new methods of management of white-pine 

 forests. 



ORIGIN AND DISTRIBUTION OF CRONARTIUM RIBICOLA. 



Some writers (76, 90) have believed that Cronartium rihicola went 

 to Europe from America on Bihes aureum, that host being associated 

 with it (but not exclusively) in the earlier discoveries of the disease 

 in Europe. Magnus, who was of this opinion at first (90), seems to 

 have completely rejected this theory and now believes that the dis- 

 ease came from western Siberia and the Swiss Alps, where it is sup- 

 posed (26, 39, 40, 93, 130, 174) to have been endemic on Pinus cembra. 

 In 1842 Klotsch issued in the exsiccatae entitled ''Herbarium vivum 

 mycologicum. No. 490," a specimen labeled ''Uredo rihicola" col- 

 lected by Lasch at Driessen. Specimens have not been seen by the 

 writer, and there is some imcertainty whether or not this is actually 

 the urcdinial stage of Cronartium rihicola. Sydow (155) gives it as 

 a synonym of C. rihicola, but he is the only author known to the 

 writer who does so. 



Cronartium rihicola was first certainly found by Dietrich (27) in 

 the Baltic provinces of Russia in 1854. He found it upon Rihes 

 nigrum, R. " rubrum," and R. " palmatum," and also upon Pinus 

 strohus, although at that time it was not known that the two forms 

 were stages of a single fungus. So far as can be determined from 

 scientific literature, it was not again noted until 1861 in Finland (81), 

 1865 in East Prussia (76), and 1869, when Eriksson (31) found it in 

 vSweden on Rihes nigrum, and Hisinger (54) noted the first outbreak 

 on pines in Finland. It had attacked Pinus strohus trees 30 years 

 old and killed them. In 1883 Rostrup (115) reported an outbreak 

 in Denmark on Pinus strohus trees 20 to 30 years old. It was evi- 

 dently then generally spread over that country. Still later, Klebahn 

 (62, 63) and Tubeuf (169) record it as generally distributed over 



