FORESTRY. 347 



the three systems, the renewing bark of trees tapped on adjacent quarters will 

 contain the most food. The advantage as to thickness of renewed bark is also 

 in favor of the adjacent-quarters system. 



Consider;'.! ion is given to the theory and practice of tapping, with special 

 reference to the Para rubber tree. 



The natural reproduction of sal and how it can be improved, R. S. Hole 

 (Indian Forester, 41 (1915), No. 10, pp. 351-361).— In this article the author 

 summarizes the chief results obtained in an investigation relative to the dying 

 back of sal (Shorea robusta) seedlings and to determine the conditions most 

 favorable for successful germination and early development of the seedlings. 



Growth and yield of spruce in high mountains, A. von Guttenberg [Wach- 

 stum und Ertvag der Fichte m Hochgebirge. Vienna: Franz Deuticke, 1915, 

 pp. 153, pis. 21, figs. 5). — A contribution to the knowledge of the growth per- 

 formance and form development of single stems and stands of spruce, based 

 largely on growth and yield data collected by the author for a number of years 

 in the forests of Tyrol and the northern Alps. 



Special importance from a scientific point of view is attached to studies 

 of growth and form in single stems as influenced by locality on the one hand 

 and stand density on the other. The large number of stem analyses made has 

 enabled the author to construct normal or model stems of spruce for various 

 localities and stem classes. In view of the lack of data on such old trees, 

 studies of some 200 to 300 year old stands in Paneveggio, South Tyrol, are in- 

 cluded in the present work. 



Willows: Their growth, use, and importance, G. N. Lamb (TJ. S. Dept. Agr. 

 Bui. 316 (1915), pp. 52, pis. 10). — In this bulletin introductory considerations 

 deal with the range of the willow tree in North America ; its various forms ; 

 soil, moisture, and light requirements ; susceptibility to injury ; and the life 

 history of the black willow (Salix nigra), which is the most important species. 

 Consideration is then given to the characteristics and uses of willow wood, 

 planting willows, cultivation and care, cutting, cost of growing, and yield from 

 willow plantations. 



Under the conditions that have prevailed in the Middle West, where most of 

 the willow plantations have been made, the average cost of growing has been 

 from 50 cts. to .$1.50 per cord, estimated on the value of the land at the time 

 of the planting. It is concluded that it should be possible at this time to grow 

 willows at $1 per cord on $25 land. The yield of willows cropped at periods 

 of about 10 years ranges from 1.5 cords per acre per year in poor situations to 

 as high as 7 cords per acre per year under exceptional conditions. 



The compilation of girth increments from sample plat measurements, 

 K. S. Troxip {[Indian] Forest Bui. 30 {1915), pp. 9). — Suggestions are here 

 given with reference to methods of compiling increment data from sample 

 plat measurements. 



The Forest Service exhibit, D. C. Ellis {Atncr. Forestry, 21 {1915), No. 26^, 

 pp. 1110-1113, figs. 5). — A descriptive account is given of the exhibit of the 

 U. S. Forest Service at the Panama-Pacific Exposition at San Francisco, 1915. 



First biennial report Nebraska Forestation Commission, C. Rohde, A. H. 

 Metzger, and W. Ball {Bicn. Rpt. Nebr. Forestation Com., 1 {1914), pp. 8). — A 

 report to the Nebraska legislature relative to the problem of afforesting the 

 state schools lands. 



List of lands in the Forest Preserve, January 1, 1914 (Ann. Rpt. Conserv. 

 Com. N. T., 3 {1913), App., pp. 503).— -This comprises a list of lands corrected 

 to January 1, 1914, belonging to the Forest Preserve of New York State. The 

 total acreage of the Forest Preserve is 1,825,882.71 acres. 



