1919] FORESTRY. 541 



tice of forestry on private lands which, it is helieved, should form the founda- 

 tion of the system to be built up through the necessary legislation by the 

 Federal and State Governments. 



Some proposals with regard to natural afforestation in a New Zealand 

 mountain area, W. G. Morrison {Neto Zeal. Jour. Set. and Techno!., 2 {1919), 

 No. 4-5, pp. 339-349, figs. 3). — The author presents observations on the progress 

 of natural afforestation on the Hanmer Plains area of New Zealand, and advo- 

 cates regeneration of other mountain areas by the introduction of seed trees 

 adapted to the environment. 



Tlie Douglas fir, a tree giving large returns, V. Manvilli {Italia Agr., 56 

 {1919), No. 8, pp. 231-237). — The author outlines the successful culture of 

 Douglas fir {Pscndotsnga, dovylasii) in various European countries, and recom- 

 mends it for mountain planting on a large scale in Italy. 



The collection and some uses of the oleoresin of Douglas fir (Oregon fir 

 balsam, Douglas fir turpentine), S. A. Mahood {Amer. Jour. Pharm., 91 {1919), 

 No. 6, pp. 345-349, fig. 1 ) .—The methods of collecting the oleoresin and its com- 

 mercial uses are briefly reviewed. 



The Hawaiian genus Kokia. — A relative of the cotton, J. F. Rock {Bd. Agr. 

 and Forestry Hawaii, Div. Forestry Bot. Bui. 6 {1919), pp. 22, figs. 8). — A de- 

 scTiptive account of the species of tliis genus. 



The true mahoganies, R. A. Rolfe {Roy. Bot. Gard. Keto, Bui. Misc. Inform., 

 No. 4 {1919), pp. 201-201). — Descriptive accounts are given of the species of 

 Swietenia, to which what may be termed true mahoganies belong. 



Mahogany, and the recognition of some of the different kinds by their 

 microscopic characteristics, H. H. Dixon {Sci. Proa. Roy. Dublin Soc., n. ser., 

 15 {1918), No. 34, pp. 431-486, pis. 23; also in Notes Bot. School Trinity Col. 

 Dublin, 3 {1919), No. 1, pp. 3-58, pis. 23). — ^A contribution from Trinity College, 

 Dublin, in which descriptions based on variations in microscopic structure are 

 given of a number of samples of mahogany. In order to facilitate the use of 

 the descriptions in distinguishing the various kinds of mahogany, a key is 

 provided which utilizes some of the characteristic microscopic features. The 

 descriptive text is accompanied by a series of plates illustrating wood structure 

 in various samples. 



A. Other methods for field experimentation with Hevea. — B. Some more 

 germination trials with Hevea seed, J. G. J. A. Maas {Arch. Rubbercult. Neder- 

 land. Indie, 3 {1919), No. 6, pp. 233-245, figs. 3). — A discussion of improved 

 methods for field experimentation with Hevea, including data on some addi- 

 tional germination trials with Hevea seed (E. S. R., 41, p. 449). 



The present germination tests with Hevea seed confirm the previous results 

 in showing that with seed preserved at ordinary temperatures the packing must 

 be moist but not air tight. When being preserved for periods longer than one 

 month the packing material should be moistened once every three or four 

 weeks. At lower temperatures, from 4 to 8° C. (39.2 to 46.4° F.), the seeds 

 will stand better a drier and more air-tight packing, but even under lower 

 temperatures the germination power decreases quickly under air-tight packing. 

 Merely ensilaging Hevea seeds in the ground appears to be good for preserving 

 seeds on the estate for periods not exceeding one month. 



Warm water treatment with water about 50° resulted in the germination 

 energy and germination power being slightly improved. Sprinkling with warm 

 water of 45° improved the rapidity of germination a little, but had no significant 

 influence on the germination power. 



The structure of cell elements in the bark of Hevea brasiliensis, W. Bobili- 

 OFF {Arch. Rubbercult. Ncderland. IndiH, 3 {1919), No. 5, pp. 222-231, figs. 7).— 

 The investigation here reported was conducted primarily witli tlie view of 



