288 SUMMARY OF CURRENT RESEARCHES RELATING TO 



render considerable service to agriculture. He describes various forms 

 of the fungus, and the cultures made by him on different media. A 

 continuation of the paper is promised. 



Soil Fungi.* — E. Dale has continued the research on soil fungi, 

 and now gives her results on three different types of soil : — Chalk soil 

 from the Gog and Magog Hills near Cambridge, taken from a wheatfield 

 to avoid recent manuring ; uncultivated mountain peat from a hill 600 

 feet above Loch Lomond ; and black-earth from reclaimed fen-land 

 near Ely. The cultures were made on raisin extract on beer-wort in 

 gelatin or agar, and also on sterilized bread, carrot, and potato. 



From chalky soil there were obtained 16 genera and 29 species, 

 Mucor and Penicillium having most representatives. From the peaty 

 soil were grown 12 genera with, in addition, a bright green mycelium, 

 and with 19 species, some of them doubtful. The " black-earth " gave 

 13 genera with 18 species, several being undetermined. A species of 

 Ozonium was isolated from the chalk and the peat, associated in each 

 case with Mucor rufescens. 



Very little is known as to the part which Fungi play in the soil ; 

 probably, as is the case with Bacteria, they aid in the disintegration of 

 dead plant tissues and make them available for growing plants. Such 

 species as all the forms of Scopulariopsis and Trichoderma album are 

 known to produce ammonia from gelatin, and experiments proved that 

 they acted similarly on plant proteins. 



Many species were found to grow luxuriantly, and all to some con- 

 siderable extent, on media containing no nitrogen leading to the direct 

 fixation of atmospheric nitrogen. The most active nitrogen formers were 

 Dematium sp., Fusarium Solani, and Mucor racemosus — all common 

 forms. In nearly all cases they grew best on vegetable media. 



American Gooseberry Mildew.f — E. S. Salmon has given a record 

 of his results in spraying for this disease, along with some observations 

 on the life-history of the fungus. Experiments were made at various 

 centres on many different kinds of gooseberry, and at different seasons. 

 It has been found that sprays containing sulphur are more efficacious in 

 dealing with the disease than those containing copper, and the former 

 have also the advantage of being non-poisonous. Lime-sulphur wash 

 gave the best results. Flowers-of-sulphur is useful only in dry weather ; 

 it is too easily washed away by rain. 



Salmon has observed that the mature fruits of the fungus, the small 

 brown perithecia, become very readily detached when mature, and fall 

 to the ground where they hibernate and reinfect the bushes in spring. 

 He therefore cautions growers against allowing diseased berries to hang 

 on the bushes. The same caution applies to diseased leaves and stalks. 



Plantations likely to prove commercially successful in withstanding 

 the effects of mildew are those generally in an open situation with the 

 bushes not too closely planted, and of a variety not liable to be injured 

 by spraying. Excessive manuring encourages luscious growth of the 



* Ann. Mycol.,xii. (1914) pp. 33-62 (5 pis). 



t Journ. Board Agric, xx. (1914) pp. 1057-79 (2 pis.). 



