FOEESTRY. 445 



Ornamental hibiscus in Hawaii, E. V. Wilcox and V. S. Holt {Hawaii Sta. 

 BuL 29, pp. GO, pis. 16). — This bulletin contains detailed descriptions of a large 

 lumber of native, introduced, and hybridized ornamental forms of hibiscus that 

 tiave been under observation at the Hawaii Station. A number of these forms 

 ire shown in color and the methods of culture, directions for hybridizing, and 

 some of the hybrids are described at length. Brief reference is also made to 

 the insects and diseases of hibiscus. 



The rational manuring of flowers and ornamental plants, R. Dumont 

 (La Funiure raisonn€e des Fleurs et des Plantes omementales. Paris, [1919], 

 pp. 152, figs. 21). — A practical treatise on the manuring of flowers and oma- 

 oieutal plants, based largely on experimental results secured by the author and 

 ather investigators. The succeeding chapters discuss the nutrition of plants; 

 horticultural soils; horticultural fertilizers; soils, composts, and amendments 

 used in horticulture; and the manu"ring of flowers and ornamental plants grow- 

 ing in the open, in pots, and under glass. 



Garden trees and shrubs, W. P. Wright {London, 1913, pp. 837, pU. 8^, 

 figs. 11). — In part 1 of this popular work the author discusses the beauty and 

 value of shrubs and trees for various situations. Part 2 deals with the arrange- 

 ment, propagation, planting, culture, and care of trees and shrubs. Part 3 

 forms a guide to the selection of trees and shrubs for various effects and pur- 

 poses. Part 4 comprises a descriptive account of the principal trees and shrubs. 

 The work is fully illustrated with colored plates and half-tone engravings. 



Shrubs of Florida, J. K. Small {New York, 1913, pp. X+140).—A handbook 

 of the native and naturalized shrubs of Florida, including a key to the orders 

 considered. 



The useful plants of New Caledonia, E. Heckel {Les Plantes Utiles de 

 NouveUe-Caledonie. Marseille and Paris, 1918, pp. 93, pis. 41, figs. 7).— This 

 comprises descriptive notes with illustrations of a number of economic plants 

 observed by the author in New Caledonia. 



FORESTRY. 



The American woods, illustrated by actual specimens with full text, 

 XIII, R. B. Hough {LomvilU, N. Y., 1918, pp. VI -^-49, pis. IS. wood sections 

 25). — The present volume of this series (E. S. R., 26, p. 442) contains sets of 

 wood sections of 25 tropical sjiecies growing in southern Florida and the adja- 

 cent keys. A systematic study of the species represented accompanies the wood 

 sections, together with a series of photographic pictures of characteristic barks 

 and foliage. 



Specific gravity and weig'ht of the most important American woods, A. 

 Gaskill {Forestry Quart., 11 {1913), No. 4, pp. 527-530) .—The author here 

 presents a table showing the specific gravity and weight of the most important 

 American woods. In order to reduce or harmonize the contradictions that 

 appear in published figures on the subject comparisons were made between all 

 available data, and spQcimens of every species were carefully analyzed and 

 compared. Densities were then more or less arbitrarily assigned which recog- 

 nize the inherent characters of the individual species. 



Relation of precipitation to tree growth, M. N. Stewait {Mo. Wcatlier 

 Rev., 41 {1913), No. 9, p. 12S7). — The author made a series of measurements of 

 an oak stump in order to discover, if possible, whether the precipitation of 

 previous years directly affected the ring widths and, if so, to determine the 

 comparative amounts of rainfall during periods for which no records exist. 

 The comparisons were confined to the precipitation during the growing season. 



