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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



wliiiie to yellow, brown, and finally black in very old specimens. 

 The sporophores are frequently edged with yellow or white. 



In external appearance in the early stages the affected timber 

 shows blackened, water-soaked, irregular areas. The decayed wood 

 is brown, irregularly fissured into tiny cubical masses which crumble 

 into dust between the fingers. 



The fungus dissolves the middle lamella of the cell walls. The 

 decay caused by L. sepiaria may be prevented or greatly retarded, 



(i) By seasoning. 



(ii) By floating the timber. 



(iii) By chemical treatment. 



Figures and Bibliography. — D. M. C. 



Timbers, Microscopic Description of Tropical. By A. D. 



Hopkinson and F. W. Neger {Beih. Bot. Cent. Bd. 29, 441-456; 

 24 figs.). — The wood specimens described were obtained in the 

 Cameroons, and include Coula, Alstonia, Sterculia, Rhizophora, Ter- 

 mimdia, &c. — G. F. S. E. 



Tobacco Culture in Wisconsin. By J. Johnson (U.S.A. Exp, 

 Stii., Wisconsin, Bull. 206; April 11; illustrated). — Tobacco culture 

 has been in practice in Wisconsin for the last fifty-seven years. The 

 best soils for the purpose are sandy loams. A good rotation is three 

 years tobacco, then barley, and cloves each one year. 



Good seed should be used and care exercised in the early stages 

 and in planting out. Bruising the leaf should be avoided in harvest- 

 ing, and for curing a properly built shed is essential, with expert 

 knowledge on the part oi the operator. — C. H. L. 



Tomato Black Spot Fungri. By F. T, Brooks and S. E. Price 

 (New Phytologist, vol. xii. No. 1; Jan. 1913; 13 figs.). — The writers 

 received for examination some diseased tomatos grown out of doors 

 near Bristol, and on the diseased portions of the fruits three fungi 

 were found — a species of Cladosporium, a species of Macrosporium-, 

 and a fungus having pycnidial fructifications. The last-mentioned 

 fungus proved to be the actual cause of the rot, the Cladosporium and 

 the Macrosporium having appeared later as saprophytes. In its 

 characters this fungus closely approaches (and may be identical with) 

 Ascochyta citrullina, which is the conidial form of Mycosphaerella 

 citrullina. This fungus causes a serious disease of melons in the 

 United States, but the perithecial stage has not yet been found ni 

 this country, and in view of the fact that the tomato is an annual it is 

 not clear how the disease is propagated from one year to another. 

 It is suggested by the writers, however, that the mycelium maji 

 hibernate in the dead tissues of affected plants, which if left on the 

 ground instead of being burnt may be the means of reinfection if 

 plants are set out on the same plot the following year. There is no 

 evidence that the fungus is propagated in the seed. On outdoor 

 plants the disease does not seem to develop until almost fully grown, 



