PROTOBASIDIOMYCETES 433 



Control. No attempts have been made to control this disease, 

 and it is doubtful if any effective method could be found, except 

 that of excluding one or the other of the two hosts from any 

 particular region. It is, moreover, possible that the uredo stage 

 may serve to transmit the disease from season to season upon 

 the rhododendron. 



XXVI. THE EUROPEAN CURRANT RUST 

 Cronartium Ribicola Fisch. de Waldh. 



HENNINGS, P. Beobachtungen iiber das verschiedene Auftreten von Cronar- 

 tium ribicola Dietr. auf verschiedenen Ribes-Arten. Zeitschr. f . Pflanzenkr. 

 12: 129-132. 



KLEBAHN, H. Ueber die Formen und den Wirthswechsel der Blasenroste 

 der Kiefern. Ber. d. deut. bot. Ges. 8: (59X70). l8 9- 



KLEBAHN, H. Neue Untersuchungen und Beobachtungen iiber die Blasen- 

 roste der Kiefern. Hedwigia29; 27-35. 1890. 



PLOWRIGHT, C. B. Fungus on Weymouth Pine and on Currants. Card. 

 Chron. 12(111): 44. 1892. 



STEWART, F. C. An Outbreak of the European Currant Rust. N. Y. Agl. 

 Exp. Sta. Tech. Built. 2: 62-74. P ls - 1-3. 1906. 



v. TUBEUF, K. Infektionsversuche mit Peridermium Strobi, dem Blasenroste 

 der Weymouthskiefer. Arbeiten aus der Biolog. Abt. f. Land- u. Forst- 

 wirtschaft am Kaiserl. Gesundheitsamte 2: 173-175. 1901. (Abstract 

 in Centrbl. Bakt. u. Parasit. 7 (Abt. II): 445.) 



Occurrence. Until within the past few years this fungus was 

 known to be of importance only in Europe, and indeed as yet 

 only sporadic cases have been found in other parts of the world. 

 At Geneva, N. Y., there was an outbreak on currants during 1906, 

 and special measures were taken to stamp out the fungus in that 

 vicinity. It appears also that the fungus is known in India. The 

 aecidial stage of this fungus was named Peridermium Strobi, by 

 Klebahn, but inoculation experiments made subsequently both by 

 the author of this species and by others have demonstrated its con- 

 nection with the uredo and teleuto forms found on currants. The 

 aecidial stage has been reported most destructive to the white pine 

 (Finns strobus) in many parts of Europe. The injuries caused 

 by the uredo and teleuto stages upon the currant are, however, not 

 of sufficient importance, of themselves, to arouse particular in- 

 terest. In this connection it is instructive to note that the white 

 pine is a native of America ; and it seems remarkable, when the 

 susceptibility of this species in Europe is considered, that the 



