Fungi, Bacteria und Pathologie. 55 



Smith, Erwin F., Completed Proof that Pseudomonas 



Stewarti is the cause of the Sweet Corn Disease of 



Long Island. (Science N. S. XVII. 1903. p. 457.) 



A brief note of a paper read on this subject (to be published in füll) 

 concerning experimental proofs that Pseudomonas Stewarti. Smith is the 

 cause of a serious wilt disease of sweet corn. Pure cultures of this 

 organism vvere sprayed over healthy plants, and in some instances 

 bacteria were placed in the drops of fluid exuding from waterpores. In 

 most cases infections resulted as shown by the complete filling of large 

 numbers of vascular bundles in the stems and leaves with the bacteria. 

 The experiments show conclusively „that wounds are not necessary for 

 infection, and makes it reasonably certain that natural infections take 

 place as a rule through the waterpores or ordinary stomata in the seed- 

 iing stage of the plants". von Schrenk. 



Smeth, Erwin F., Observations on a Hitherto Unre- 



ported Bacterial disease, the cause of which 



enters the Plant thron sjh Ordinary Stomata. 



(Science N. S. XVll. 1903. p^ 456.) 



A disease of Japanese plums affecting leaves and fruits is described 

 as due to a yellovv bacterium, Psendomanas priini Smith. The particular 

 point of interest lies in the fact that the bacteria enter into the tissues 

 of the leaves and the fruits through the ordinary stomata. At first con- 

 fined to the substromatic Chambers, the bacteria rapidly push into the 

 deeper tissues, forming cavities of considerable size. In an advanced 

 stage „the bacteria reach the surface as numerous tiny, rounded, pale 

 yellow, gumllke masses, which ooze from the stomata lying under the 

 closed bacterial cavity". The disease is primarely one affecting the paren- 

 chyma but the bundles are finally invaded. Infection takes place principally 

 in May and June and no wounds are necessary. A description of the orga- 

 nism is given together with cultural characteristics. von Schrenk. 



Stevenz, Frank Lincoln, Notes o n Sclerospera gvaminicola. 

 (Journal of Mycology. IX. February 1903. p. 13.) 



This fungus, first reported as Peronospora graininicola in W i s c o n s i n 

 is now found to be very-common on Oxoplioriis viridis (L.) Nash in 

 New York. G. G. Hedgcock. 



Vuillemin, Paul, Importance taxinomique de l'appareil 



zygospore des Miicorinees. (Bulletin de la Soc. mycol. 



de France. T. XIX. 1903. p. 106—118.) 



La zygospore offre un caractere de premier ordre du groupe des 

 Mucorine'es ; ses moditications accessoires n'ont pas une valeur aussi 

 generale, mais elles fournissent de precieux renseignements sur le degre 

 de parente des divers genres, au meme titre que les caracteres des 

 autres organes de Vegetation ou de multiplication. 



En etudiant dans un meme genre plusieurs especes pourvues de 

 zygospores, on demontre la faibie importance de la coloration, du mode 

 d'ornementation de la membrane, de la position respective des tympans 

 d'insertion, du recloisonnement des gametes. En comparant plusieurs 

 genres, on est amene ä distinguer, dans les appendices qui enveloppent 

 la zygospore, deux organes tres differents: les fulcres qui sont une 

 dependance directe de !a fructification comme chez les Erysibees, et les 

 iilaments vegetatifs qui representent une portion du thalle annexee ä la 

 fructification. 



D'apres cette consideration, les Mucorine'es sont divisees en G y m - 

 nosporees et en C ar p ospore es. Les Phycomyces et les Absidia 



Botan. Centralbl. Bd. LCIII. 1903. 5 



