42 EXPERIMENT STATION EECOED. 



The successive chapters discuss the life history of a tree; tree growth in 

 relation to climate and soil; pure and mixed woods; nursery management; 

 sowing and planting in the forest ; tending of woods ; methods of treatment ; 

 protection of woods against destructive animals, birds, and insects, weeds and 

 fungi, and against frost, drought, storms, and fires; silvicultural notes on broad- 

 leaved trees and conifers; fencing and draining; felling and measurement of 

 timber ; working plans ; and the uses of British timber. 



■Wood and forest, W. Notes (Peoria, III., 1912, pp. 309, figs. UO).—A band- 

 book of information relative to the sources, growth, properties, identification, 

 and uses of the common American woods. 



The successive chapters discuss the structure and properties of wood, the 

 principal species of American woods, the distribution and composition of the 

 North American forests, the forest organism, natural enemies of the forest, 

 the exhaustion of the forest, and the use of the forest. Information for dis- 

 tinguishing different woods is appended, also a general bibliography on wood 

 and forestry. 



Sixty-six species of American woods are considered relative to their habitat, 

 characteristics of the tree, appearance of wood, physical qualities, and common 

 uses. Illustrations are given in each case of the leaf of the tree and of the 

 radial, tangential, and cross sections of the wood. The woods are also listed 

 hi order of their weight, strength, elasticity, and hardness. 



On forest types, A. K. Cajandeb (Fennia; But. 8oc. Geogr. Finlande, 28 

 (1909), No. 2, pp. IV}-n5). — This comprises a detailed study of the forest 

 flora in a number of German forest districts, conducted principally to deter- 

 mine to what extent a knowledge of plant groups is of value for scientific 

 forestry investigations and for practical forestry, A similar study of the 

 forms in the vicinity of Brixen is appended. 



For the region studied the author found that the dominant forest forms fell 

 into a comparatively small number of types, which were readily characterized 

 by certain dominant plants of the gi'ound flora. The forest types were widely 

 distributed and the same type was found to occur at altitudes ranging from 

 5 meters to GOO meters. The author concludes that the occurrence of a forest 

 type is not exclusively influenced by any one factor, such as the physical and 

 chemical composition of the soil, exposure, altitude, etc., since the same type 

 is found on various soils and exposures. The forest types appear to be much 

 more the result of the total effect of locality factors than as formations which 

 occur on similar biologic localities. The ground vegetation does not appear to 

 be materially influenced by the dominant tree or trees. Each forest type 

 appears to have a special growth energy. The accretion of the same timber 

 species in different tyi^es is quite variable, but within the same type there 

 are no great differences. Within one and the same forest type similar re- 

 generation and silvical methods are applicable to the same timber siwcies. 



Experiments on the periodicity of some tropical trees, H. Dingler (Sitzber. 

 K. Bayer. Akad. Wiss., Math. Phys. KL, 1911, No. 1, pp. 127-].'i3).—ln order 

 to throw some light on the cause of the normal leaf fall which occurs with 

 many native species in Ceylon during the drought period in March, the author 

 conducted pruning experiments with many of the species growing in the 

 Peradenyia Botanic Garden and Experiment Station and elsewhere. 



The results, as here tabulated and discussed, show that if the trees are 

 pruned in the fall the resulting vigorous new leaf growth formed in December 

 passes through the normal leaf-fall period without dropping off. From these 

 results the conclusion is formed that the normal leaf fall of these tropical 

 trees can not be attributed primari.ly to external conditions of the temi)erature, 

 moisture, etc., and that measures taken to control the temperature and moisture 



