ZOOLOGY AND BOTANY, MICROSCOPY, LTC. 453 



Influence of Nitrogenous Manures on the Form of Cereals. * — 

 H. Clausen finds that nitrogenous manures tend to increase the length of 

 the lower portions of the stems of cereals, whilst the upper portions are 

 relatively shortened. Nitrates have much more effect than ammonium 

 salts. The elongation of the lower internodes renders the stems weaker, 

 hence, although more grain is produced when ammonium salts are used, 

 the crop is less liable to be laid than when nitrates are employed. 



Soils suitable for Chestnuts.f — L. Piccioli concludes from exami- 

 nation of the soils and subsoils of Italian chestnut forests, that the trees 

 require a moderate amount of lime, but that as much as 8 p.c. is very 

 injurious. The injurious action may to some extent be neutralised by 

 application of potash. The author recommends a manure suitable for 

 chestnut forests. 



Nutrition of Hops.i — T. Eemy and O. Englisch find the maximum 

 growth to occur during flower and fruit production. In the spring the 

 perennial portions of the plants contain 30 to 40 p.c. of the total nitrogen, 

 potassium, and phosphoric acid required ; assimilation from the soil is 

 at first slow but afterwards increases, reaching a maximum when the fruit 

 develops ; when the hops are ripe assimilation ceases. The assimilation 

 of calcium and magnesium seems to continue after the ripening period. 

 The hop requires very considerable amounts of these two minerals, more 

 even than red clover ; large amounts of potassium are also necessary. 

 Nitrogen, potassium, and phosphoric acid migrate from the stems and 

 leaves before their death to the fruit ; but there is at the same time a 

 gain of calcium and magnesium in the leaves. The roots also acquire 

 more nitrogen, potassium, and phosphoric acid. 



Value of Green Manures.§ — F. Hanusch made plot experiments on 

 a large scale to determine the relative value of the crop. The nitrogen 

 and ash content, both in the portions above ground and in the roots, were 

 determined. The most remunerative crop was found to be white clover, 

 followed in order of diminishing value by vetches, horse-beans, and 

 field-peas. 



Value of Kainite. || — M. Gerlach finds, experimenting with barley 

 in soil poor in potassium, that kainite produced far better results than 

 high per cent. " potassium salts " containing the same amount of potas- 

 sium. This is due to the fact that the kainite contained twice as much 

 sodium chloride as the " potassium salts," and the author agrees with 

 Wagner, that sodium economises potassium partly by liberating the 

 latter from the soil and partly by satisfying the mineral requirements 

 of the crop. In the case of potatoes, " potassium salts " have the advan- 

 tage, as compared with kainite, that they contain less chlorides. 



Shifting in Heads of Sunflower during Development from 

 Flowering to Ripening.il — B. Leisering states that the alterations in 



* Journ. Landw., xlix. (1902) pp. 365-88. See Journ. Chem. Boa, 1. a, p. 283. 



t Bied. Centr., xxxi. (1&02) pp. 75-6. See Journ. Chem. Soc , 1. c, p. 285. 



X Bl. Gersten-, Hopfen- u. Kartoffelbau, 1900, p. 457. See Journ. Chem. Soc., 

 1. c, p 168. 



§ Zeit. Landw. Versuchswes. Oesterr., 1901, p. 772. See Journ. Chem. Soc, 

 1. c., p. 169. 



|| Fuhling's landw. Zeit., 1901. pp. 11, 12. See Journ. Cbetn. Soc., 1. c, p. 170. 



«j[ Flora, xc. (1902) pp. 378-432 (3 pis.). 



