300 FORESTRY [Bot. Absts. 



follows: The heath is burned, then plowed and disced and allowed to remain thus three years, 

 plowed again a little deeper and in a manner to break up all roots and again left for 2 years. 

 This process brings about aeration, bacterial life decomposition and formation of humus. In 

 some places lime and phosphoric acid are plowed under in the fall. A species of scrub pine 

 is planted with one of Norway spruce to two of pine. The pine requires very little air and 

 soil moisture, aids in formation of humus and protects the spruce. — ./. A. Larsen. 



2046. Pammel, L. H. Effect of winter on shrubs at Ames, Iowa. Rept. Iowa State 

 Hortic. Soc. 53: 39-41. 1918.— See Bot. Absts. 4, Entry 868. 



2047. Parnell, Ralph, and others. Progress report on forest administration in the 

 North-West Frontier Province for the year 1917-18. 15 + xxi p. Peshawar, India. 1918. 

 — A routine report on forest operations in the province. There was a marked increase in 

 the out-turn of timber, and the departmental exploitation of wood fuel and charcoal also in- 

 creased materially. A total of 12,716 cubic feet or timber and fuel per square mile was pro- 

 duced, or nearly double that of the next provincial competitor (Bihar & Orissa). The finan- 

 cial results indicate that a vigorous commercial forest policy is desirable. — E. R. Hodson. 



2048. Petrini, Sven. Om uppskattning av hojdtillvaxten a staende trad. [Calculation 

 of height growth of standing trees.] Skogsvardsforen. Tidskr. 17: 19-24. 1919. 



2049. Record, Samuel J. Storied or tier-like structure of certain dicotyledonous woods. 

 Bull. Torrey Bot. Club 46: 253-273. 1919— See Bot. Absts. 3, Entry 2442. 



2050. Rolfe, R. A. The true mahoganies. Kew Bull. 1919:201-207. 1919.— Com- 

 mercial planting of mahogany trees in the West Indies in recent years has made it necessary 

 to establish taxonomically the various species. The original mahogany is Swietenia ma- 

 hagoni, a tree known in the West Indies for more than three centuries and often called Span- 

 ish Mahogany, but in recent years the term mahogany has been extended to include various 

 red-brown timbers belonging to this and other genera of the family Meliaceae and in part to 

 other families. The present paper is an account of the history and botanical features of 

 Svnetenia mahagoni, S. humilis and S. macrophylla. — E. M. Wilcox 



2051. Rutgers, A. A. L. Selectie en uitdunning. [Selection and thinning.] Arch. 

 Rubbercult. Nederlandsch-Indie 3: 105-118. 1919. — Article emphasizing the necessity of a 

 systematic selection of rubber trees for size and high latex yield, and also the removal of a 

 large number of practically valueless trees on the plantations of Sumatra and Java and 

 Ceylon. Selection may be made by collection of seeds from superior seed trees or by propa- 

 gation through budding. Data is given to show that in thinning out from 15 per cent to even 

 75 per cent of the trees on the plantations the yield is not reduced but either remains con- 

 stant or is increased. — W. E. Cake 



2052. Sampson, Arthur W. Suggestions for instruction in range management. Jour. 

 Forestry 17:523-545. 1919. — The forester must have a thorough knowledge of the live- 

 stock business and the subjects which would give the student an insight into range manage- 

 ment are described as to application, ground to be covered, related topics and usefulness. 

 The subject matter is discussed under seven heads for the grazing course proper, and for 

 related topics. The type of man and the character of the work are portrayed. — E. N. Munns. 



2053. Sanford, F. H. Progress in blow sand control. Michigan Agric. Exp. Sta. Quart. 

 Bull. 1: 130-131. Feb., 1919. — A brief account of some experiments begun in 1916 to control 

 the blowing of sand on the dunes along Lake Michigan, using cuttings of Carolina poplar 

 and basket willows set in belts to form temporary sand catchers, supplemented by barriers 

 of beach grass. — E. A. Bessey. 



