174 JOUENAL OF THE KOYAL HORTICULTURAL SOCIETY. 



position as regards other genera of that order. The primary flora is 

 divided into 1, Littoral or mangrove; 2, Strand; 3, Marsh; 4, Savan- 

 nah; 5, Savannah woods; 6, Dipterocarp woods; 7, Dipterocarp high- 

 land woods; 8, Teak forest; 9, Mixed deciduous highland wood; 10, 

 Evergreen forest; 11, Evergreen highland woods, in which Quercus and 

 Lauraceae divisions are distinguished; 12, Pine woods; 13, Eock and 

 limestone mountain flora. 



There are also secondary associations, such as 1, Eice-fields; 2, 

 Jungle-fire association; 3, Small stretches about old temples; 4, Sacred 

 teak groves; and 5, Sandbank flora. The new species described here 

 for the first time belong to the following genera: — Mastigohryum, 

 Acanthocladium, Genato'phyllum, Tricliostomum, Tephrosia siamensis 

 J. E. Drummond, Rhododendron Ludwigianum Hors.— G. F. S. E, 



Silver-leaf disease of Fruit Trees, Preliminary note. By 



H. T. Giissow (Phytopathology, i. 6, pp. 177-9). — The author reports 

 the discovery of this disease in Nova Scotia and in other parts of 

 Canada. A description of the disease is given and an account of work 

 hitherto done with it. The successful reproduction of it by inoculation 

 with Stereum purpureum is also reported. — F. J. C. 



Soil, Injurious Substances in the. By 0. Schreiner and T. J. 

 Skinner (Bot. Gaz. pp. 161-81, Sept. 1910). — The authors extracted 

 an organic constituent (dihydroxystearic acid) from the soil. This 

 is injurious to the growth of wheat in water, even when potash, phos- 

 phate, or ammonia fertilizers are present, but has least influence in I 

 presence of nitrogen, and when the ratios of these fertilizers are I 

 favourable to plant life. It affects the withdrawal of fertilizers byj 

 the roots, and especially affects and deforms the roots.- — G. F. S. E.\ 



Soil Moisture and Desert Veg-etation. By B. E. Livingston! 

 (Bot. Gaz. pp. 241-56, Oct. 1910; with 4 figs.).— Details of determina- 

 tion of soil moisture, depth of water and rainfall in four habitats near 

 Tuscon are given. These four habitats are distinguished by different 

 vegetations. The amount of water retained by the soil seems to be £ 

 very important factor in studies of distribution.— G. F. S. E. 



Soils of the Columbia River Valley, Suggestions to Settler? 

 on the Sandy. By B. Hunter and S. 0. Jayne {U.S.A. Dep. Agr. 

 Bur. PI. Ind., Circ. 60; July 1910; 2 figs.).— This bulletin gives muct 

 information of value to those for whom it is intended, especially witl 

 regard to irrigation and the most suitable crops to grow. — A. P. 



Soils of the Eastern United States— the Portsmouth Sand] 



Loam. By J. A. Bonsteel {U.S.A. Dep. Agr., Bur. of Soils, Circ 

 24, May 1911). — This occurs mainly in the tide-water portion of th 

 coastal plain from Maryland to Mississippi, and there are about 774,00 

 acres of it. When drained it constitutes an excellent soil for con: 

 oats, and market garden crops, but the expense o! deairing and drain 



