Eumycetes. — Pflanzenkrankheiten. 415 



Britain. One of these, Bourdetia Eyrii, is described for the first 

 time, while from the discovery of fresh material a detailed de- 

 scription is furnished of Hypochnella violacea, Schroet., Peniophora 

 Allescheri, Bres. is considered from the study of the material avai- 

 lable to be not specifically distinct from P. cremea, Bres. 



E. xM. Wakefield (Kew). 



Welsford, E. J., Nuclear Migrations in Phragmidium viola- 

 cenm. (Ann. Bot. XXIX. p. 293—298. 1 pl. April 1915.) 



This paper forms a confirmation of the main contentions in 

 Blackman, V. H. On the Fertilization, Alternation ofGenerations, 

 and General Cytology of the Uredineae. (Ann. Bot. XVIII. 1904). 

 The author shews that a re-examination of Phragmidnifn violaceuni 

 completely confirms Blackman 's Observation that fertilization is 

 brought about by the migration of a vegetative nucleus to a fertile 

 cell. That the nuclear migrations are not due to traumatic Stimuli 

 is shewn by the facts that: 1) They occur in regulär sequence from 

 the middle to the periphery of the aecidium. 2) They are not found 

 in the paraphyses at the periphery of the aecidia where the cells 

 are nearer to the wounded surface. 3) They are found in material 

 fixed in various ways. Agnes Arber (Cambridge). 



Pethybridge, G. H., Investigations on Potato Diseases. 

 (Sixth Report). (Journ. Dep. Agric. Techn. Instr. Ireland. XV. 

 NO 3. p. 491—526. April 1915.) 



The Diseases dealt with in the present report are Phytophthora 

 infestans, Sclerotinia sclerotiorum, Phytophthora erythroseptica, Spon- 

 gospora stibterranea j Hypochmis Solani, Spondylocladiiini atrovirens, 

 Ordinary or Brown Scab, Spicaria Solani, and a few miscellaneous 

 pests. 



Phytophthora erythroseptica was proved by inoculations from 

 pure cultures to be capable of producing a „wilt" in the overground 

 portions of the potato plant, as well as a rot of the tubers. 



Experiments with foreign varieties of potato as regard immu- 

 nity to Spongospora were not successful, in that all those tried 

 became infected. 



With regard to Hypochmis Solani the work of Rolfs was con- 

 firmed by the comparison of cultures from the basidiospores and 

 from the sclerotia [Rhisoctonia Solani, Kühn). The damage done by 

 this fungus is not regarded as serious, nor is that due to Spondy- 

 locladiiini atrovirens, since neither producing any form of „rot" in 

 the tuber. 



.,Ordinary" Scab was shown to be not due to mechanical Irri- 

 tation, but probably to micro-organisms. since it was not developed 

 in soils which had been sterilised. E. M. Wakefield (Kew). 



Pethybridge, G. H., The Possible Source ofOrigin ofthe 

 Leaf-Spot Disease of Cultivated Celery. (Journ. Roy. 

 Hort. Soc. XL. Part 3. p. 476-480. 1915.) 



The author records the finding of Septoria Petroselini, var. Apii 

 on wild celery, in a remote part of Ireland free from cultivated 

 plants. By infection with spores from the wild plant, he succeeded 

 in producing the disease on cultivated plants, and in more virulent 



