636 „ EXPERIMENT STATION RECORD. [Vol.35 



striking effects as regards position and contour produced by wind action in 

 connection witli growth and death in thickets of P. spinosa in exposed situations 

 on the seashore. 



DifEerences in resistance of plants to injurious influences, F. Steanak 

 {Vestnik 5. Sjes. Ces. Lek. PHr., 1915, p. 425; abs. in Bot. Centbl., 129 {1915), 

 No. 15, p. 378). — Important phases ot the resistance of plants to attack are 

 their anatomical structure (as mechanical tissue or impregnation with silica), 

 morphological characters (as thickness of stems in cereals), chemical constitu- 

 ents of the plant body (as silica or lime), and vegetative period. 



The effects of illuminating gas on plants, P. Sokavek {Landw. Jahrb., ^8 

 {1915), No. 2, pp. 279-312, pi. 1, figs. 2).— Previous investigations (E. S. R., 

 26, p. 532) have been followed up with a study of the various effects of illumi- 

 nating gas in the soil on several sorts of wild or cultivated plants, largely 

 trees. The results are detailed as regards the influences noted, including reac- 

 tions by the plants. It is thought that, while a number of indications are 

 found which, taken together, may be considered as characteristic of root injury 

 by gas, no single symptom, as for example changes in leaf coloration, can be 

 depended upon as a certain indication of gas injury to roots. 



The influence of sulphur dioxid on plants, R. Trnka {Vestnik 5. Sjez. Ces. 

 Lik. PHr., 1915, p. 431; abs. in Bot. Centbl, 129 {1915), No. 15, p. 378).— Plants 

 are said to take up into their active green tissue sulphur dioxid in different 

 proportions. This is thought to form sulphurous or sulphuric acid and to inter- 

 fere greatly with the formation of vegetable matter. 



Secretion by roots of substances toxic to plants, M. Molliard {Rev. O^n. 

 Bot., 27 {1915), No. 322, pp. 289-296, pi. i).— Work previously reported (E. S. 

 R., 30, p. 522) has been followed up by further tests with peas. These are said 

 to show that the plants excrete substances which prove toxic to plants grown 

 thereafter in the medium previously used. The effect was increased after the 

 medium had been twice used. 



Injurious effects from ivy growing on trees, C. von Ttjbeuf {Naturw. 

 Ztschr. Porst. u. Landw., 13 {1915), No. 10, pp. 476-481, figs. 5).— This is a 

 further account, with discussion, of stem constrictions of plants (E. S. R., 31, 

 p. 343). 



FIELD CROPS. 



Field crops, D. N. Prianishnikoff {Uastnoe Zemledielie. Moscotc: V. 

 Rikhter, 1914, pp. 513-\-15, pis. 144, figs. 2). — This work deals with cereal, root, 

 and leguminous crops, together with other plants grown for oil, fiber, dye, and 

 spice production. Attention is also given to tobacco and other plants used for 

 their narcotic effect. The culture and uses of the different crops are consid- 

 ered in detail and the control of diseases and insect enemies is outlined. The 

 work has reference to the culture of the different crops in Russia. 



[Irrigation experiments at Bromberg] {Jahresber. Kaiser Wilhelms Inst. 

 Landw. Bromberg, 1914, pp. 38-50). — Potatoes were given 30, 140, and 160 

 mm. (1.2, 5.6, and 6.4 in.) of irrigation water, applied by sprinkling, in addi- 

 tion to a rainfall of 195 mm. during the growing season. A forage variety, 

 Gertrude, yielded 13,209 lbs. of tubers per acre without irrigation and 15,262 

 lbs., 15,440 lbs., and 19,099 lbs. per acre when receiving 30, 140, and 160 mm. 

 of irrigation water, respectively. Magnum Bonum, a table variety, yielded 

 4,462 lbs. with only the natural rainfall and 10,710 lbs. and 10,978 lbs. per acre 

 with 140 and 160 mm. of irrigation water, respectively. On the assumption that 

 both rain and irrigation water was completely used by the plants, it is pointed 

 out that it required on the average of all tests 556 lbs. of water to produce 1 lb. 



