276 Physiologie. — Fungi, Bacteria und Pathologie. 



55, 70, 77, 85, 88 ^/o gekeimt; die hemmende Wirkung selbst 

 recht schwachen Lichtes ist überall deutlich. 



Topfversuche lehrten, dass dementsprechend bedeckte 

 Samen rascher und in grösserer Zahl keimten als obenauf- 

 liegende; auch nachträgliche Bedeckung der Samen (nach Ab- 

 lauf von 10 Tagen) erhöhte die Keimzahl nur wenig. — Die 

 biologische Bedeutung des Verhaltens ist noch durchaus fraglich. 



Die Versuche mit farbigem Licht, die nicht in völlig ein- 

 wandsfreier Weise angestellt werden konnten, haben das auf- 

 fallende Resultat, das die höchsten Keimzahlen im grünen 

 Licht auftraten. Hugo Fischer (Bonn). 



Atkinson, Leo Fr. and Robert Shore, Mushroomgrowing for 

 amateurs. (Bull. Cornell. Agricl. Expt. Station. CCXXVIl. 

 p. 415—424. 1905.) 



A populär treatinent of mushroom growing including: places sui- 

 table for niushrooms, preparation of material, growth, time to pick, etc. 



Perley Spaulding. 



Clinton, G. P„ Report of Botanist. (Conn. Agric. Expt. 

 Station Report. 1904. p. 311—384.) 



Short notes concerning the following diseases of plants are given: 

 Pseudopezlza medicaginis on Medicago sativa, Podosphaera leucotricha, 

 Gymnosporangiiim macropus, Ventnria inaequalis and winter injury to 

 Pinis malus, Piiccinia asparagi, Darliica filiim on Asparagus officinale, 

 Bacterial spot on cotyledons of Pliaseoliis liinniiis, Peronospora para- 

 sitica on Brassica oleracea, Sclerotinia frnctigena on Prunus avium, 

 Helminthosporium turcicnm on Zea mays, Plasmopara cubensis on Cu- 

 cumis sativus, Tuhurcnlina persicina on Rubus canadensis, Fusarium 

 wilt of Solanum melongena, Sterigmatocystis ficuum on Ficus carica, 

 Uncinula necator on Vitis sp., Bacillus bubonianus on Monis sp., Bac- 

 terial rot and Plasmopara Cubensis on Cucumis melo, Botrytis on Allium 

 cepa, Sclerotinia fructigena and winter injury of Prunus persica, Ven- 

 turia pirina on Pirus communis, Sclerotinia fructigena on Prunus sps., 

 Bacillus solanacearum, Phytophthora infestans, Corticium vagum and 

 Clospora Scabies on Solanum tuberosum, winter injury of Ligustrum ja- 

 ponicum, Rhizoctonia on Raplianus sativus, Leptosphaeria coniothyriuni 

 and winter injury on Rubus sp., Rhizoctonia on Rheum rhaponticum, 

 Puccinia arenariae on Clianthus barbatus, Black spot of Nicotiana 

 tabacum. 



The writer treats the downy mildew or blight of muskmelons and cu- 

 cumbers quite fully. Tliis disease is caused by the fungus Peronoplasmo- 

 para cubensis (B. and C.) Clinton. The early history of the trouble is 

 traced from its discovery in 1868 in Cuba. It was first found in the 

 United States by Halsted in 1889 and has been reported nearly 

 every year since. In 1899 Massee states that the trouble has reached 

 England; it has been repoited from many other countries including 

 Russia, Brazil, Java, and G e r m a n E a s t A f r ica. Its hosts all be- 

 long to the cucurbit family and it has been reported mostly from the 

 cultivated species. A discussion of the systematic position of the fungus 

 is given and the writer concludes that a separate genus should be made 

 for it. He accordingly raises B er lese 's subgenus Peronoplasmopara 

 to generic rank and states the characteristics of the three genera, Pero- 

 nospora Cda., Peronoplasmopara Berl., and Plasmopara Schrot. A re- 

 vised and more complete description of the species is also given. The 

 life history of the fungus is given in detail, especially with reference to 

 the germination by means of zoospores, this not having been carefully 



