446 Pflanzenkrankheiien. 



loin des pustules, il pense que le Champignon n'a pu persister qu'ä 

 l'etat de mycoplasma. 



La rouille amene une diminution de la teneur en sucre de la 

 Betterave, P. Vuillemin. 



Ewart, A, J., On Bitter Fit and the Sensitivityof Apples 

 to PoisoQ. (Proc. Roy. Soc. Victoria. XXVI. p. 12-44 3 pl. 1913.) 



This paper is a continuation of the author's previous work 

 (Proc. Roy. Soc. Vict. XXI\^ p. 367. 1912), in which he shewed 

 that pitting in apples may be produced by the absorbtion of very 

 small quantities of poisonous substances. It is now shown that such 

 artificially produced pits are retarded in development by low tem- 

 peratures, as Bitter Pit has long been known to be. 



The expressed sap and carbon dioxide are practically nonpoi- 

 sonous to the pulp cells, and certain substances norraally formed 

 as cell-products, as alcohol and tannic acid, are less poisonous than 

 manj?- nutrient salts when applied singly. Mc Alpine's theory of 

 Bitter Pit, and the evidence brought forward by him against the 

 poisoning theory, is discussed in considerable detail. Against the 

 vascular Interruption theory it is argued that in the early stages 

 of Bitter Pit the vascular connections are normal, and the accumu- 

 lation of starch and of an increased proportion of ash in the Bitter 

 Pit tissue proves that the conducting Channels are functioning actively. 



The browning of apple pulp is due to the oxidation of lannic 

 acid, which occurs in the form of gallotannic acid in minute vacuo- 

 les in the protoplasm, and as an iron-greening tannin in the cell-sap. 



Some experiments on anaerobiosis are added. Yates' apples are 

 apparenth'^ not capable of more ihan a months anaerobiosis in hy- 

 drogen or carbon dioxide at room temperature. Apples may be 

 preserved some months at ordinär}^ room temperatures b}^ coating 

 them with a gelatine skin. PeniciUiurn was found to grow vegetati- 

 velv on pelled apples or protato slices immersed in kerosene. 



E. M. Wakefield (Kew). 



Maffei, L., Una malattia della Gerbera causa ta dell'^cso- 

 chyta Gerherae n. sp. (Riv. Patol. veget. VI. 9. 3 pp. 1913.) 



Taches et fletrissure des feuilles de Gerhera Jamesoni, deter- 

 minees par Ascochyta Gerherae n. sp. „Maculis amphigenis, magnis, 

 castaneo-brunneis, tenuiter vinoso rnarginatis, subconcentrice stria- 

 tis; picnidiis punctiformibus. 170— 180— 90— 100 ,u diam ; sporulis 

 ovoideis vel oblongo ellipsoides, 8 — 10 — 2-3/<, rectis, utrinque ro- 

 tundatis, initio continuis, deinde uniseptatis. non constrictis, guttu- 

 latis, hyalinis." C. Bonaventura (Firenze). 



Montemartini, L., Alcune malattie nuoveorareosservate 

 nel Laboratorio di Patologia vegetale di Milano. (Riv. 

 Patol. veget. VI. 7 pp. 1913.) 



1. Une maladie des concombres nouvellc pour Fltalie: 

 deformation des fruits, täches noires, gommose, sous l'action de 

 Clados.porii(ni cucumeriuiim Ell. et Arth (C/. citcumeris Frank); ce 

 parasite des Cucurbitac(!es, connu de l'Amerique et de quelques 

 localitees d'Europe, avait ei€ Signale en Italie sur quelques fruits 

 pres de Verone, mais son action pathogene n'avait pas encore ete 

 constat^e. 



