370 Pflanzenkrankheiten. 



Haiepa 1909, s'attaque aux feuilles de Cinnamomum seylanicum et 

 cause une sorte de cancer du Cannellier, beaucoup plus grave ä 

 Java qu'ä Ceylan. Les galles renferment souvent un Hymenopiore 

 Traconide qui, d'apres E. Green, pourrait etre utilise pour detruire 

 VEriophyes. p - Vuillemin. 



Fischer, C. E. C, Note on the Biology of Pestalossia Hartigii 



Tubeuf. (Journ. of Econ. ßiol. London. IV. Sept. 1909. p. 72—76. 



1 Plate,) 



Pestalossii Hartigii has been supposed to be the active agent 



of a seedling tree disease in Europe, but the evidence is based on 



its constant appearance when the constrictions characheristic ol the 



disease are present. An attempt was made to investigate the question 



further and it was found that the fungus grew readily as a saprophyte 



in artificial cultures. A number of inoculation experiments were per- 



formed but in no case did infection result. It is suggested that 



infection may only take place at certain seasons of the year. 



A. D. Cotton (Kew). 



Jensen, Hj., Onderzoekingen over tabak der Vorsten- 

 landen. (Untersuchungen über den Tabak der Vor- 

 stenlanden). (Verslag 1908. Batavia, 1909. 8°. 44 pp.) 



Der Bericht enthält eine Uebersicht der verschiedenen, für die 

 Praxis wichtigen, Untersuchungen. 



Verfasser konnte nachweisen, dass die Schleimkrankheit des 

 Tabaks von Bakterien verursacht wird und übertragbar ist, befindet 

 sich damit in Uebereinstimmung mit den Befunden Uyeda's. Bei 

 früheren Untersuchungen misslang die Infektion, weil gesunde, 

 kräftige Pflanzen infektiert worden, die eine grosse Resistenz be- 

 sitzen! Die Infektion scheint nur stattzufinden wenn die Wurzeln 

 beschädigt worden sind und wird gefördert, indem man spät mit 

 dem Indieoabfall düngt, wodurch eine saure Gährung im Boden 

 verursacht wird. Th. Weevers. 



Johnson, T., Further observations on Powdery Potato- 

 Scab, Spongospora subterranea (Wallr.). (Sei. Proc. Royal Dublin 

 Society. XII. 16. Jury 1909. 3 plates.) 



The beginning of the paper treats of nomenclature and syste- 

 matic position. The author regards the organism as a Myxomycete 

 and adopts the name Spongospora subterranea (Wallr.) (= 5. Solani, 

 Brunch. and 5. Scabies Massee) see Centralblatt Bd. CVIII. p. 300. 



The remainder of the paper fills up some gaps in the author's 

 previous aecount of the development of the organism and gives 

 notes on the prevention of the disease. 



The cavities or plasmogenetic intercellular Spaces of the sponge- 

 like spore-ball are regarded as corresponding to the vacuoles of the 

 sporogenous Plasmodium. The spores themselves are comparable to 

 those of Ceratiomyxa. 



The Plasmodium carries the disease from the seed-tuber through 

 the stoloniferous branches into the new tubers. Wedges of scabby 

 tubers (from which the spore-balls had been removed) grafted into 

 sound tubers produced infection, which appears to indicate that 

 restins; Plasmodium can communicate the disease. The growth of 

 the parasite is favoured by wet soil, dry soil on the other hand 

 stimulates the produetion of wound cork. A. D. Cotton (Kew). 



