840 EXPERIMENT STATION RECORD. (Vol.43 



in relation to asricultiire, and a bihlioRrapliy of West African forests. Special 

 consideration is given to the Nigerian timber trees. 



Forestry in Rhodesia, J. S. Hi:nkel {Rhodesia Agr. Jour., 17 (1920), No. If, 

 pp. 335-339, pis. 2). — Notes are given on timber trees in the Umtali Park. 



Forests and silviculture in warm-arid regions, A. Pavabi (Agr. Colon. 

 [Italy], IJf (1920), No. 8, pp. 326-3/f5).—A brief examination of the principal 

 aspects of the forests and forestry in tropical and semitropical arid regions 

 of the world. 



Tolerance of forest trees and its relation to forest succession, G. P. Burns 

 (Jour. Forestry, 18 (1920), No. 6, pp. 610-615).— In this contribution from the 

 Vermont Experiment Station, the author briefly reviews some of the litera- 

 ture dealing with tolerance of forest trees with the idea of showing that the 

 word tolerance does not mean to all foresters a light relationship only ; that 

 it is a confusing term ; and that if its use is to be continued, it should be given 

 an exact definition. 



Timber line and climate character, H. Bkockmann-Jerosch (Schweie. 

 Naturf. Gesell. Pflanz. Geogr. Komm., Beitr. Geobot. Landesaufnahnie, 6 (1919), 

 pp. VIII +255, pis. If, figs. 11). — A contribution from the Plant Geographical 

 Commission of the Swiss Natural Research Society. This work comprises a 

 study of timber line in relation to various climatic factors and various com- 

 binations of these factors. The introductory chapter discusses the method of 

 conducting the investigation. In the succeeding chapters, consideration is 

 given to the timber line in the Swiss Alps and In the north and south polar 

 regions of the world. Comparisons are then made between the alpine timber 

 line and the polar timber lines. The continental timber line is considered in its 

 relation to both the alpine and polar timber lines. In the final chapter the 

 author presents certain conclusions relative to the effect of various climatic 

 factors on timber line and the formation of different plant groups. A 

 bibliography of consulted literature is appended. 



The technique of natural reproduction once and now, Ebekhard (Forst- 

 wiss. Centbl., 42 (1920), Nos. 5, pp. 161-183; 6, pp. 20If-226).—K study of forest 

 regeneration practices in Germany. 



The care of the woodlot, B. R. Mokton (Dept. Int. Canada, Forestry Branch 

 Bui. 69 (1920), pp. 52, figs. 28). — The bulletin supersedes Circular 10 of the same 

 series. It discusses protection, thinning, improvement cuttings, pruning for 

 marketable timber, reproduction, collecting tree seed, and the farm nursery. 

 It also contains notes on various species of trees and tables of distances and 

 quantities. 



Forest fires in Canada, 1918, R. G. Lewis (Dept. Int. Canada, Forestry 

 Branch Bui. 70 (1920), pp. 20, figs. 12). — This is a statistical report for 1918 on 

 forest fires in the several Provinces of Canada, with reference to areas burned, 

 causes, damage, and areas patrolled. 



Air maps for flying patrols (Canad. Forestry Mag., 16 (1920), No. S-9, pp. 

 1,06, IfOl, fig. 1). — The method of map squaring adopted by the Quebec Forestry 

 Branch, forest fire protective associations, and several large paper and lumber 

 companies who operate aerial surveys and patrols of timber limits is illustrated 

 and described. 



Yield tables for single trees of deodar, kail, chil, spruce, and silver fir, 

 C. G. Trevor (Indian Forester, 1,6 (1920), No. 9, pp. 1,39-1,51). — The data given 

 are the results of large numbers of measurements recorded during the last 20 

 years in the Kulu forest division of India. 



The soap tree, L. Tbabut (Prog. Agr. et Vitic. (Ed. VEst-Centre), 1,0 (1919), 

 No. 17, pp. 398-1,01). — A brief account is given of the importation in 1845 and 

 subsequent history of a Sapindus, its varieties, and the utility of its products. 



