FORESTRY. 539 



the above yield can be easily increased by HO per cent with a considerable 

 increase in profits. 



The cultivation of coffee, H. V. Jackson (Dcpt. Af/i: X. .S'. Wales, Fanners' 

 Bui. .'/, pp. 8, figs. 7). — This consists of popular notes on coffee culture prepai'ed 

 with a view of stimulating the industry in New South Wales. 



Yerba mate or Parana tea, O. Warburg and F. Wohltmann (Troprnpflan- 

 zcr, Bcilicfte, 11 (1010), No. 1, pp. 63, figs. 13). — This report, which is prepared 

 from official data collected by E. Heinze, German Consul for the State of 

 Parana, relative to the yerba mate industry in the State of Parana, Brazil, is 

 intended to supplement previous accounts of the yerba mate industry in South 

 America, such as that by Neger and Vanino (E. S. R.. 15, p. 365). Information 

 is given relative to the literatui'e and sources of yerba mate, the production of 

 the raw material, preparation and export of the tea, economic status, and recent 

 statistical information relative to the industry. 



Investigations in connection with the African palm oil industry (Bui. 

 Imp. Inst.. 7 (190'.)), \o. Jf. pp. 357-39Jt). — This consists of a summary of 

 various reports on the palm oil industry made by the director of the Imperial 

 Institute to the British West African colonies. It contains information relative 

 to areas occupied by the oil palm (Eleais guineensis) in West Africa, its dis- 

 tribution in the different colonies and countries, the relative values of the 

 several varieties for the production of palm oil and palm kernels, and the 

 methods used for the extraction of these products. 



Green manuring in the Tropics, J. S. J. McCall (ytjasaland Agr. and For- 

 estry Dept. [Pub.], 1909, Xo. 2, pp. .'/). — A brief popular pamphlet setting forth 

 the importance of green manures for soil improvement with special reference to 

 their use in connection with coffee, rubber, and other tropical crops. 



Trees in Washington, W. S. Thornber {Washington Sta. Popular Bui. 23. 

 pp. Jf). — As a result of extended tests made by the station of shade, forest, 

 and ornamental trees, more than 100 trees have proved themselves valuable 

 for conditions in the State. Suggestions ai'e here given relative to propagating, 

 transplanting, and care and cultivation of trees, together with lists of trees 

 most W(jrthy of mention, and those suitable for special purposes. 



FORESTRY. 



Surface conditions and stream flow, W. L. Hall and H. Maxwell (C7. S. 

 Dept. Agr., Forest Serv. Circ. 176. pp. 16). — An examination of the flow of 10 

 important rivers of the United States on which careful records have been kept 

 for periods ranging from 10 to .34 years, shows a steady increase in the number 

 and duration of floods during this period. This circular discusses the various 

 causes which might increase flood conditions, such as precipitation, evapora- 

 tion, tempei'ature, topography and geology, natural and artificial reservoirs, 

 soil, and ground cover, and attributes the principal causes of increased floods 

 to the clearing away of the forests on the mountainous watersheds of the 

 streams described, together with the repeated burning over of forest lands, 

 thereby reducing the thickness and value of the ground cover, lessening the 

 power of the soil to absorb and store water, and destroying the undergrowth 

 and brush, finally resulting in erosion and rapid run-off of water. The water- 

 shed of the Cumberland River is discussed as one where conditions have grown 

 worse, and that of the Red River as one where conditions have grown better. 



The reforestation of sand plains in Vermont, C. D. Howe (Bot. Gaz., 49 

 (1910), Xo. 2. pp. 126-148, figs. 15. map i).— This is a study in the succession 

 of forest types on sand plains bordering on Lake Champlain. Consideration 



3512<S— No. 6—10 4 



