144 EXPERIMENT STATION EECORD. [Vol.36 



the effect of the spruce type of forest in retaining the snow at high altitudes. 

 It is further pointed out that the advantage of the treeless catch basins lying 

 above the timber line for the formation and retention of large snow drifts is 

 due, not to the fact that they are treeless, but to their location in regard to 

 precipitation, wind, and summer climate. The part that the present stands 

 of spruce play in keeping the snow as high as possible is the important point, 

 and has a direct bearing on the value of reforesting the many burned areas 

 in the high mountains at the head of streams. 



Evaporation and soil moisture in relation to plant succession, C. F. Kok- 

 STAiN (Proc. Soc. Amer. Foresters, 11 {1916), Ko. >}, pp. 430-433). — A review of 

 some literature on the subject. 



Silvical notes on western larch, J. A. Laesen (Proc. Soc. Amer. Foresters, 

 11 (1916), No. 4, pp. 434-440). — Notes on the growth performance of western 

 larch in mixed stands and its adaptation to different sites and soils. 



Slash pine, an important second-growth tree, W. R. Mattoon (Proc. Soc. 

 Amer. Foresters, 11 (1916), No. ^, pp. 405-416, fig. 1). — An account of the slash 

 pine (Pinns caribcea) with reference to its present range of distribution, fac- 

 tors of local distribution, important silvicultural characteristics, value of lum- 

 ber, and production of turpentine. 



The natural root grafting of conifers, H. S. Nkwins (Proc. Soc. Amer. For- 

 esters, 11 (1916), No. 4, pp. 394-404, figs. 6).— Studies conducted by the author 

 relative to the natural root grafting of conifers led to the conclusion that this 

 phenomenon is common only between trees having an affinity for each other, 

 and is due moreover to pressure exerted by two or more opposing roots in 

 combination with a number of physical factors. The phenomenon of the 

 " growing stump " as observed among conifers is most common with Douglas 

 fir and is the result of conjunctive symbiosis which is made possible by the 

 natural root graft of the stump with a living tree. 



Chemistry as an aid in the identification of species, A. W. Schokgee (Proc. 

 Soc. Amer. Foresters, 11 (1916), No. 1, pp. 33-39). — The author cites authorities 

 to show that although the oil from the same species may differ in quantity in 

 different localities, the quality remains identical. The results are also given 

 of an examination of the volatile oils from a number of western species of 

 pine, with particular reference to distinguishing between Jeffrey pine, western 

 yellow pine, and "cross variety " western yellow pine, which species are 

 usually hard to distinguish between in the field. 



" The data obtained by chemical analyses have shown that ' cross variety ' 

 western yellow pine should be referred to Piniis ponderosa and that there is 

 no relation between ' cross variety ' pine and P. jeffreyi. There are also indi- 

 cations of the occurrence in California of typical specimens of P. ponderosa 

 scopuloriim. The oils from P. ponderosa and P. ponderosa scopulorum are 

 distinctly different and justify the separation into two forms. Oils from west- 

 ern yellow pine from Arizona and Colorado agi'ee closely, while oils examined 

 from the State of Washington agree with the typical oils from P. ponderosa 

 of California, showing that the defined difference in geographical distribution 

 of the species and its variety is supported by a difference in the composition 

 of the oils." 



Comparative test of the Klaussner and Forest Service standard hyp- 

 someters, D. K. Noyes (Proc. Soc. Amer. Foresters, 11 (1916), No. 4' PP- -i^~- 

 424). — The test here noted was conducted on a number of permanent sample 

 plats established by the Forest Service of the U. S. Department of Agricul- 

 ture in California. 



The results in general showed that the Klaussner hypsometer is only from 60 

 to 80 per cent as fast as the Forest Service hypsometer, depending on the size 



