380 Pflanzenkrankheiten. 



Gussow, H. T., New Lilac leaf-disease in England. (Gard. 

 Chron. XLIV. Dec. 12, 1908, p. 404—5. 2 figs.) 



A disease of Lilacs [Syringa vulgaris) in which the leaves show 

 brown streaks and blotches is described. The writer attributes the 

 disease to a bacterium which he identifies as Pseudomonas Syringae, 

 Beijerinck. A. D. Cotton (Kew). 



Johnson-, T., Chrysophlyctis endohiotica Schub. (Potatowart or 

 Black Scab) and other Chytridiaceae. (Scient. Proc. Dublin Roy. 

 Sog. XII. June 1909. p. 131 — 144. 3 plates.) 



The paper provides the first detailed accQunt of the life-history 

 of Chrysophlyctis endobiotica, Schilb., the fungus causing the well 

 known Black Scab of the Potato. 



In the early stages the Plasmodium is seen in the host plant, 

 and may be distinguished from the surrounding protoplasm by being 

 denser, homogeneous and finel}^ granulär. It destroys first the nucleus 

 and then the protoplasm and may be seen passing through the cell- 

 wall from one cell to another. The host-plant reacts by active cell- 

 division, and produces the wart-like growth. Two forms of repro- 

 duction are recognised 1. summer zoosporangium, and 2. winter or 

 resting sporangia. The former provide for the spread of the fungus 

 during the growing season, and the escape of the spores are said 

 by Schilberszky to be readily observed if the sporangia are placed 

 in water. The winter sporangia are the familiär resting "spores", 

 which as is well-known germinate with difficulty. They have long 

 been the subject of investigation and not until last autumn was their 

 germination observed. 



The origin and development of the resting sporangia was followed 

 out, and Chrysophlyctis was found to be holocarpic as the entire 

 vegetative body is used up in the formation of the sporangium. 

 Germination takes place most readily on potato juice. The zoospores 

 are very minute (1.5—2.4 ;»), pear-shaped and uniciliate. The infec- 

 tion of the potato tubers was not observed; the author however is 

 of opinion that Black Scab is not only propagated by means of 

 spores, but by the internal passage of the Plasmodium from diseased 

 tubers into the new tubers of the next season. 



As to the systematic position of Chrysophlyctis the author regards 

 it as a member of the Olpidiaceae and allied to Asterocystis radicis. 



The paper also deals with other members of the Chytrydiaceae, 

 especially Urophlyctis leproides (Beet tumour), and ^si^erocj's/Zs radicis 

 (Flax yellowing), and concludes with remarks on some marine species. 



A. D. Cotton (Kew). 



Massee, G., A Funtumia Disease (^Nectria Fimtumiae Massee). 

 (Kew Bull. III. p. 147—148. 1909.) 



Describes a disease of Funtumia elastica Stapf, caused by the 

 fungus Nectria Funtumiae n. sp. Both Fusarium and Nectria stages 

 are present. The disease has shown itself in Oganda and in appea- 

 rance is similar to that of Slime Flux. A. D. Cotton (Kew). 



Massee, G., Plant Diseases. IX. Dry Scab of Potatoes [Spon- 

 dylocladium atrovirens, Harz.). (Kew Bull. I. p. 16—18. with fig. 1909.) 



A Short account of the potato disease caused by Spondylocladium . 

 The Sclerotium stage, known as Phellomyces sclerotiophorus, Frank, 



