ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 3^1:9 



as known. MeJanopsameUa, a now genus of Melanommeae, is founded 

 on EriospJideria insequaJis Grove ; the conidialforni is Gonytrichum. He 

 finds that the genus Fchnsias is synonymous with Fracchisea. Several 

 new species are described. A. L. S. 



Amount of Copper required for the Control of Phytophthora 

 infestans.— 0. Butler {riiytopathology, 1020, 16, 298-804). The 

 author records results arrived at from spraying experiments carried out 

 in 1911>, a season very favourable to the spread of the disease. The 

 amount of copper necessary per acre per annum Kes between twenty-four 

 and twenty-six pounds. A. L. S. 



The Skin Spot Disease of Potato Tubers.— (t/ow/v?. A(jric., 11)20, 

 26, 1245-50, 1 pi.). The paper is an abridged and modified version of 

 a report of work done by Miss M. N. Owen on the disease, and published 

 in the Kew Bull., X. 8, 1919. It is a disease that develops in storage, 

 but it is not yet known whether infection takes place in the soil or 

 during storage. The fungus, at first considered to be Spkaria Solani, 

 has now been referred to Oospora pustulans sp. n. ; it is confined to the 

 surface layers of the potato, but may be so disfiguring that the commer- 

 cial value of the tubers is very much lowered, and " eyes " may be 

 pre\'ented from forming. The writer advises the avoidance of spotted 

 potatoes for planting. A. L.^S. 



Clover Stem-rot.— A. D. Cotton {Journ. Agric, 1920, 26, 1241-4, 

 1 pi.). This disease is due to Sderoiinia trifoUorum. It usually makes 

 its appearance in November, and spreads as a sparse white mould over 

 the foliage. In bad cases the fungus invades the roots and kills the 

 plants outright. The sclerotia in the soil may retain their vitality for 

 years. An interval of eight or twelve years should be allowed before 

 re-sowing with clover. A. L. S. 



Diseases of the Rhododendron. — Henry Schmitz {Pliytopatholoijy , 

 1920, 10, 278-8, 1 pi.). Descriptions of some of the more important 

 diseases of rhododendron, both wild and cultivated, on the Pacific coast. 

 The writer made cultures and inoculations of various parasites : Sporo- 

 cyle Azalese, a bud rot ; Melamp^oropsis piperiana, a rust on a native 

 rhododendron ; and various other leaf parasites. He investigated also 

 the vsitches-brooms of the native plant, bat could not determine the 

 causal agent. A. L. S. 



Rot of Date Fruit.— J. G. Broavn {Bot. Gaz., 1920, 69, 521-9, 

 5 figs.). This disease was worked out by the author in Arizona Dates 

 had been brought to him very badly aft'ected. On examining the trees 

 many dates were found to be rotted, others were dry and mummified. 

 Careful cultures showed that the fruit was first attacked by Alteniariciy 

 which induced mummification, but if the first attack were followed by 

 AsperyiUus and PeniciUium on the diseased areas, the date_s were quickly 

 destroyed. A. L. 8. 



Entyioma Ranunculi injurious to Helleborus niger. — C Arnaud 

 {Bull. Soc. Path. vey. Frame, 1919, 6, 10-12 ; see also Bull. Ayric. 

 Intell. PL Pis. Rome, 1919, 10, 747-8). The fungus attacks the 



