Fungi^ Bacteria und Pathologie. 181 



Black BoU is characterised by the decay of the internal parts of 

 the boll Lisually starting at the base, while the outside is apparently 

 healthy. The seeds swell up inside during the later stages (probably a 

 kind of premature germination) and all the lint is destroyed. The only 

 foreign organism present in the diseased bolls, is a short rod shaped 

 non-motile bacillus and this is constantly present in the diseased 

 tissues. Till further evidence is obtained the author regards this bacillus 

 as the primary cause of Black-Boll. Treatment is suggested to prevent 

 the attack of the disease, and the selection of varieties that appear im- 

 tnune is recommended as the most hopeful course to pursue. The well 

 known diseases caused by Uredo gossypü, Cercospora gossypina, and 

 Colletotricliuin gossypii are also dealt with. A. D. Cotton (Kew). 



Massee, George, A new orchid disease. (The Gardeners 



Chronicle. Vol. XXXVOI. Aug. 1905. p. 153. I text fig.) 



The disease recorded occured on Oncidiiim plants imported from 

 America. The parasite proved to be a species of Hemilcia, which 

 is nanied by the author H. americana sp. nov. The fungus forms 

 bright orange powdery patches of variable size on the under surface of 

 the leaf. Remembering the havoc caused by Hemilcia vastatrix on 

 Coffee, orchid growers should take every means to check the spread 

 of the new disease. A. D. Cotton (Kew). 



Massee, George, Cactus Scab. (The Gardeners Chronicle. 

 Vol. XXXVIII. Aug. 1905. p. 125. 1 fig.) 



A description of a Cactus disease which has long been known in 

 Great Britain. The fungus however had not hitherto been observed 

 in its fruiting condition and its identity has been obscure. The author 

 discovers the disease to be due to Diplodia opiintiae Sacc. 



A. D. Cotton (Kew). 



Nadson, G. und A. Raitschenko, Zur Morphologie von 



Enteroinyxa paludosa Cieiik. [Aus dem botan. Laborator. 



des medicin. Frauen-Instituts in St. Petersburg. No. V.] 



(Sep.-Abdr. aus Scripta Botanica Horti Universitatis Petro- 



politanae. Fase. XXIII. St. Petersburg 1905). Russisch (p. 1 



— 15) mit deutschem Resume (p. 16—18). Mit Tafel I— IV. 



Verf. fand diesen, wie es scheint sehr seltenen Myxomyceten-'di\\x\- 

 lichen Organismus in der Umgegend von St. Petersburg. Der leb- 

 haft blau-grün gefärbte Plasmakörper von Enteroinyxa ist vielkernig und 

 von einer ziemlich dicken farblosen Schleimhülle umgeben. Die Ver- 

 dauung der verspeisten Synechococcus-ZeWen, von denen die Enteromyxa 

 sich ausschliesslich ernährte, geschah entweder in den Nahrungsvacuolen 

 oder unmittelbar im Entoplasma. Enteromyxa vermehrt sich durch 

 Fragmentation oder aber durch Sporen. Dabei zerfällt der Plasmakörper 

 in Klümpchen, welche zu Sporocysten werden. Im Innern der letzteren 

 entstehen 1 — 20 (gewöhnlich 3—6) Sporen. Die Keimung der Sporen 

 wurde nicht beobachtet. Nach der Ansicht der Verff. kann man 

 Enteromyxa als eine primitive, niedrig or^anisirte Form in der Reihe der 

 Myxoniyceten — Endosporeen auffassen , andererseits erinnert sie mit 

 ihren stark entwickelten Schleimhüllen an einige der einfachsten 

 Foraminiferen und zwar an die Gruppe der Myxothecinae von 

 Rhumbler. W. Tranzschel. 



Petersen, H. E., Contributions ä la connaissance des 

 Phycomycetes m a r i n s (Chytridlnae Fischer). (Oversigt 

 over det kgl. Danske Videnskabernes Selskabs Forhandlinger. 

 1905. No. 5. p. 439—488. Avec 11 figures dans le texte.) 



