192 Pflanzenkrankheiten — Pteridophyten. 



10. Bis zu den Ergebnissen weiterer Forschungen können vor- 

 läufig als Gegenmittel empfohlen werden: 



a. Auswahl gesunden Saatgutes von Feldern, die vor dem 

 Abreifen der Sorte solange das Laub noch grün ist, besichtigt 

 worden sind. 



h. Regelmässige Entfernung aller kranken Stauden vom Felde, 

 eventuell Bezeichnung derselben und separate Ernte. 



Köck (Wien). 



Murril, W.A., The Chestnut Canker. (Torreya VIII. p. 111 — 112. 



1908.) 



Additional notes on the fungus disease of chestnut which was 

 described several months ago under the name Diaporthe parasitica. 

 The disease is spreading very rapidly and it seems that it will be 

 but a Short time until all species of chestnut both native and exotic 

 will be affected. R. J. Pool. 



Pole Evans, J. B., Coffee Rust {Hemüeia vastatrix, Berk. & 

 Bz.). (Ann. Report Transvaal Agric. Depart. 1906—1907. p. 165. 

 Published 1908.) 



Coffee growing, is a decayed industry in the Transvaal 

 owing to the ravages of Hemüeia vastatrix. In 1903 it was pointed 

 out that a closely related fungus, Hemileia Woodii, Kalchbr. and Cke. 

 occurred on two native South African shrubs Vangueria infausta 

 and V. latifolia, and it was conjectured that these fungi would be 

 able to pass from one host to the other. 



Recently, experiments have been undertaken to test the truth 

 of this surmise. Cultures of H. vastatrix on Coffee and H. Woodii 

 on V. infausta were kept under Observation for over 12 months. 

 The experiments show conclusively that the rusts are not inter- 

 changeable. W. E. Brenchley. 



Pole Evans, J. B., The Citrus Fruit-rot, caused by Penicil- 

 liurn digitatum. (Fr.) Sacc. (Transvaal Agric. Journ. VII. 25. 

 p. 60-62. 1908.) 



The citrus fruit-rot Penicilliiim digitatum, occurs almost exclusi- 

 vely on citrus fruits. It first appears on the fruit as a white furry 

 growth, which is preceded by a softening of the affected parts. The 

 white growth spreads rapidly over the fruit, and later on gradualty 

 turns in olive green colour from the centre of affection; observations 

 go to show that the mould cannot of itself gain an entrance to the 

 fruit, but that it finds a ready ingress through the slightest injury 

 to the rind. The Suggestion is made that in the course of time if 

 the fungus is allowed to flourish unchecked, it may graduall}^ 

 acquire the property of penetrating the thin skinned varieties of 

 Sound, uninjured fruit. W. G. Brenchley. 



Apmoup, H. M., On the Sorus of Dipteris. (New Phj'^tol. Vol. VI. 

 p. 238—244. 4 textfig. 1907.) 



The author has investigated the sorus of Dipteris hifurcata (Lob- 

 biana) in which the sori are arranged in two rows, one on each 

 side of the midrib on the under surface of the narrow lamina. The 

 densely crowded sporangia of the sorus show no definite orientation 

 and arise simultaneously. The soral characters of this species are 



