642 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Stems, whence the myceHum passes each year into the growing-points 

 of the aerial shoots. It has been found that while in slow-growing 

 plants, like species of Primula, the duration of the fungus in the annual 

 shoots is assured year after year, the hyphse are unable to keep pace 

 with the extension in length of the shoots of plants of rapid growth, 

 so that the fungus disappears after a certain number of years and the 

 plant finally becomes free from the parasite. — F. C. 



Soil Fumigation. By J. A. Hyslop (Jour. Econ. Entom. vii. 

 pp. 305-312 ; Aug. 1914). — The author records the results of experi- 

 mental soil fumigation with sodium cyanide in both laboratory and 

 field against wireworms. The impure salt (containing 74 to 76 per cent, 

 sodium cyanide) was sown on the soil at the rate of 300 lb. to the acre, 

 with the result that all the wireworms were killed. This was done 

 at the beginning of October. At this rate and also at half this rate 

 the plants were killed as well, so that it appears unsafe to add sodium 

 cyanide for fumigating purposes while plants occupy the soil. The 

 cyanide was sown six inches beneath the surface. — F. J. C. 



Soil, Fungous Flora of the. By C. N. Jensen {U.S.A. Exp. 

 Stn., Cornell, Dep. PI. Path., Bull. 315 ; 1914). — The fungous flora 

 of the soil is taken to consist of obhgate saprophytes and facultative 

 parasites, the former in far larger numbers than the latter. 



Some facultative parasites, such as RMzopus nigricans, Tricho- 

 derma Koningi, and Pythium Debaryanum, are ver}^ widely distributed. 



A considerable number of soil fungi and bacteria are described and 

 figured, and a good bibliography of previous work on this subject is 

 given, dating back to Kuhn's work on plant diseases in 1858. 



D. M. C. 



Soil Particles, Distribution of. By the Duke of Bedford, K.G., 

 F.R.S., and Spencer U. Pickering, M.A. F.R.S. (Wohurn, 14th Rep., 

 1914, pp. 37-45). — Preliminary experiments on the effect of rain on 

 the flocculation of the soil. They show that the proportion of fine 

 particles in a surface soil is increased by the amount of rainfall during 

 approximately the previous three weeks. This is a factor which is 

 amply sufficient to cause considerable difference in the behaviour of 

 plants in the same soil on different occasions. — A. P. 



Sparrows, Some Observations on the Food of Nestling. By W. E. 



CoUinge {Jour. Bd. Agr. vol. xxi. No. 7, pp. 618-623).— During 

 1913 and 1914 the writer examined the stomach contents of 287 

 nesthng sparrows. Of these 200 came from fruit-growing districts 

 and the rest from suburbs. The results are tabulated in detail. 



From an examination of these tables it is seen that in a single 

 day one hundred nestling house sparrows require nearly 2000 insects 

 for food in fruit-growing districts, and about a third of that quantity 

 in suburban districts. Further, with the exception of a few spiders 

 and earthvv^orms, the whole of the food consists of injurious insects. 



