640 EXPERIMENT STATION RECORD. 



not tapping of the mother tree on the germination energy of the seed and 

 germination power, on the formation of linees and rings on the seedlings, on the 

 development of complicated curves in the seedlings, and on the length of month- 

 old plants. 



The study was conducted according to biometrical methods. The results are 

 presented in a series of tables and fully discussed. 



A silvicultural system for western yellow pine in the Black Hills, P. T. 

 Smith {Proc. Soc. Amer. Foresters, 10 {1915), Xo. 3, pp. 29 J/SOO) .—The systems 

 here recommended and discussed are the shelterwood system for even-aged 

 stands and the group-selection system for mixed-aged stands. 



Influence of the weather on the height growth in pine A. P. Tolskii 

 {Trudy Li^sn. Opytn. Dielii Ross., 47 {1913) ; abs. in Zhur. Opytn. Agron. {Riiss. 

 Jour. ExpL handle), 15 {1914), ^'o. 1, pp. 106, i07).— The author reports a 

 study conducted in the Borov Exi>eriment Forest in the Government of Samara 

 relative to the height growth of pines as influenced by meteorological conditions 

 during different seasons of the year. 



Some uses of meteorological studies in silvicultural and management 

 problems, W. H. Kenety {Pioc. Soc. Amer. Foresters, 10 {1915), No. 3, pp. 

 266-270). — Some of the results obtained at the Cloquet forest station on 

 studies of meteorological factors and their influence on forest types are given 

 under tlie heads of air temperature, soil temperature, and soil moisture. The 

 moisture equivalent metliod for determining soil types (E. S. It.. 19, p. 416) 

 has been found at tlie station to be the most usable one. The application of this 

 method is here described. 



The reforestation of brush fields in northern California, R. H. Boerkeb 

 {Proc. Soc. Anicr. Foresters, 10 {1915), No. 3, pp. 2S4-293). — This paper de- 

 scribes in detail an apparently successful operation in reforesting a brush area 

 by planting, the absence of seed trees making the process of natural regenera- 

 tion a diflicult one. 



Windfall damage in selection cuttings in Oregon, K. Smith and U. H. 

 Weitkneciit (Pror. Soc. Amer. Foresters, 10 {1915), No. 3, pp. 263-265). — A 

 detailed study of 3,021 windfalls, 2,160 of which were yellow pines, was con- 

 ducted on nearly 4,000 acres of cut-over land in order to determine the prin- 

 ciples which control windfall. 



The results of the investigation show in substance that no diameter cla.ss 

 above 12 in. is immune from wind-throw, the liability increasing with the 

 diameter. The danger of wind-throw increases with the height of the trees, the 

 density of the crown, and witli the grouping of trees as opposed to their even 

 distribution. The character of the trunk of the trees has very little effect 

 upon their wind firmness. Windfall is apparently as great on medium and deep 

 soils as on shallow soils, and is more prevalent on cut-over land than in virgin 

 timber. It occurs indiscriminately without regard to slope or exposure, but is 

 slightly more severe on ridge tops and lee slopes than elsewhere. 



The trees of Texas, I. M. Lewis {Bui. Univ. Tex., No. 22 {1915), pp. TI+ 

 169, figs. J/S). An illustrated manual of the native and introduced trees of the 

 State. The descriptions given are based largely upon specimens in the her- 

 barium of the University of Texas. The discussion of each species includes its 

 distinguishing characteristics, range, and uses. A key is given to the families 

 and genera included. 



The forests of Alaska, II. S. Graves {Amer. Forestry, 22 {1916), No. 265, pp. 

 24-37, figs. 16). — A descriptive account of the forests and forest conditions in 

 Alaska, in which the author calls special attention to the relation of the 

 National Forests to the development of industries in Alaska. 



