618 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Mycological Notes.* — W. B. Grove continues his notes on new or 

 rare species, with an account of various microfungi. Amphichseta 

 eicropsea, a new genus for Britain, though the species was collected by 

 Berkeley in 1857. Another species, EpocJmium macro sporoideiim 

 Cooke, was placed by Saccardo in Stemjjhylimn, and is now again 

 recorded. Other species are recorded and commented on. 



Spanish Microfungi.f — Romualdo Gonsalez Fragosa has published 

 a complete list up to date of the microfungi observed by himself and 

 by other workers in the province of Cataluna. In the preface he 

 enumerates these other workers, and explains his method of compiling 

 the lists, pointing out the advantage and necessity of giving the locality 

 as well as the substratum or host of each species. In all 307 species are 

 listed, a few of them being new to science. 



Diseases of Plants. J — The " blossom-wilt and canker " disease of 

 apple-trees has been described by H. Wormald. It is caused by the 

 fungus Monilid, cinerea, and has caused gz-eat loss in some districts. The 

 first evident symptoms of the disease is the blossom-wilt condition ; the 

 flowering stalks begin to wilt and are frequently killed. The more serious- 

 canker condition follows through the penetration of the fungus into the 

 deeper tissues of the branches. It was found that the spores of MoniUa 

 cinerea germinated in a few honrs. When germinated on the stigmas of 

 the flowers the tube travelled down the styles to the centre of the 

 flower, then along the flower-stalk into the spur ; wilting of the leaves 

 occurred about a fortnight after infection. Methods of controlling or 

 eradicating the disease are suggested. 



W. H. Martin § has established the identity of Sclerotium bataticola, 

 a parasite of sweet-potato, with a similar parasite of pepper. On breaking 

 open the fruits numerous small black sclerotia were found in the interior 

 and also on the seed. Cultures were made and inoculation experiments 

 were undertaken, which were uniformly successful on a broken or 

 wounded surface. A number of different plants were thus infected with 

 the parasite. 



Mel. T. Cook || found a disease of Norway maples to be due to a 

 Nectria ; the dead branches had been girdled by a canker, and the older 

 cankers were covered with Tubercnlaria pustules, a stage in the life- 

 history of Nectria. Infection takes place by wounds, and the Nectria is 

 chiefly saprophytic, though it becomes parasitic when it gains entrance 

 to the tissues. 



Damping-off of tomatoes has been traced by J. E. Howitt If to 

 an attack of Phytophthora infestans on the stems near the surface of the 



* Journ. Bot.,lv. (1917) pp. 134-6 (2 figs.). 



t Musei Barcin. Sci. Nat. Opera Ser. Bot. Barcelona, ii. (1917) 187 pp. (1 pL 

 and 22 figs.). 



J Journ. Board Agric, xxiv. (1917) pp. 504-13 (4 pis.). 

 § Phytopathology, vii. (1917; pp. 308-12 (10 figs.). 

 11 Phytopathology, vii. (1917) pp. 313-14. 

 i Phytopathology, vii. (1917) p. 319. 



