418 Fungi, Bacteria und Pathologie. 



liehe Körper („oeufs") von derselben Farbe bis zur Dicke von 3 — 4 cm.. 

 Aus ihnen entwickeln sich besonders nach einem Regen die Frucht- 

 körper des Pilzes Das Mycel greift den Weinpfahl und den Stamm des 

 Weinstockes zu gleicher Zeit an. 



Die befallenen Weinstöcke erkennt man an folgenden Merk- 

 malen: Die Blattränder werden braun und sehen wie versengt aus, der 

 Stamm verkrüppelt, seine Fruchtbarkeit vermindert sich und er stirbt 

 schliesslich ab. Am häufigsten tritt der Schädling auf dem Ezerjo und 

 Mezes Feher auf, wo sandiger Boden vorherrscht. Er erscheint da 

 zweimal im Jahre: Ende Mai und Ende August — bis Herbst. Die be- 

 fallenen Stämme und Weinpfähle müssen mit Kalciumbisulfit (8— 107<'ig) 

 und die Weinstöcke mit 3 — 5 Litern (1 — 2"/oig) desselben Stoffes be- 

 gossen werden. Das „cordon mycelien" durchbohrt die Wurzeln^ bildet 

 auch um die Wurzeln enge Scheiden und sendet Saugwerkzeuge in das 

 Innere derselben. Verf. schildert nun die Zerstörung der Gewebe der 

 befallenen Wurzeln und die sich bildenden Krystalle auf dem Mycel_, 

 ferner die oft rasch vor sich gehende Bildung der Fruchtkörper und die 

 Beschaffenheit der einzelnen Teile desselben. 



Die oben genannte Milbe (Coepophagus echinopiis) ist in Ungarn, 

 aufgetreten^ macht Gänge in der Rinde und dringt später in den Holz- 

 körper der Wurzel ein, ohne jedoch das Mycel des Ithyphalliis zu be- 

 rühren. Glyciphagen und Angidlluliden finden sich auch in den von 

 dem Pilze zerstörten Wurzeln vor. Matouschek (Reichenberg). 



Salmon, E. S., Further Cultural Experiments with 

 ,,Bi ologic Fo r m s" oi the Eiysiphaceae. (Ann. Bot. XIX. 

 1905. p. 125—148.) [Read at the British Association Cam- 

 bridge. 1904.) 



In a recent paper the author described a method of culture by 

 means of which the conidia of biologic forms of Erysiphe Graminis can 

 be induced to infect leaves of most species which normally are immune 

 to their attacks. 



In the present paper experiments are described in which ascospores 

 were used under the same method of culture and in which the same in- 

 fection results were obtained. 



Further experiments are then described in which leaves were in- 

 jured and thereby rendered susceptible to the attacks of conidia and 

 ascospores, which are unable to infect the leaves when uninjured. The 

 injuries were inflicted by stabbing the leaf, stamping out minute portions, 

 pressure from weights, and action of narcotics, or heat. It is pointed 

 out that injuries similar to those artificially produced in the experiments, 

 must constantly be inflicted on the plants in nature by animals, frost^ 

 wind, and hail. A case is also mentioned of barley leaves being ren- 

 dered susceptible by the agricultural Operation of rolling corn. 



The term x^noparasite is proposed by the author for a speci- 

 alized form of a parasitic fungus, when growing on injured parts of a 

 Strange host, or on injured parts of its usual host which are immune 

 previous to injury (e. g. after a thick cuticle is developed). The term 

 oecoparasite is suggested for the specialized form when growing on 

 its proper host under normal conditions. 



As an explanation of the susceptibility of injured leaves, the 

 assumption is made, that in consequence of the vitality of the leafcells 

 being affected, the protection normally aftorded by enzymes or similar 

 substances ceases. The term vitality is used „to express the sum of the 

 individual physiological processes at work in the cell. External factors 

 which affect the normal balance in the working of the individual physio- 

 logical processes, increase or decrease the vitality of the plant." The 

 loss of immunity brought about by causes which affect the vitality of the 

 leaf, find their parallel in instances of induced susceptibility in animals 

 to certain bacterial diseases. 



