igiy] CURRENT LITERATURE 419 









recent publication, 8 the joint product of a botanist and a forester. The former 

 seems to have contributed many details concerning the floristic and ecological 

 composition of the many variations in the dipterocarp forest. The quanti- 

 tative data regarding the physical climatic factors are among the first to be 

 collected in tropical forests according to modern methods. Soil moisture 

 determinations for every month in the year, although unfortunately not 

 accompanied by the wilting coefficient of the soil, show that the soil is quite 

 uniformly moist throughout the year. Atmometer records throughout the 

 year give for the first time the data for an adequate comparison with the evapo- 

 rating power of the air in mesophytic forests elsewhere. In the dipterocarp 

 forests of Mount Maquiling the maximum, minimum, and average daily rates 

 of evaporation upon the floor of the forest are respectively 5.3,0.7, and 2 . 5 cc, 

 as compared with 10.6, 3.3, and 7.1 cc. obtained by the reviewer 9 in the 

 mesophytic beech-maple forest of northern Indiana. The evaporation data 



■ 



are especially good because they are given not only for the floor of the forest 

 but also for the second story trees, where there is protection by the general 

 canopy of foliage, and give a maximum, minimum, and average daily rate of 

 7. 5 ? i.8, and 5.3 cc. respectively, and for the atmosphere above the tree 

 tops, where the maximum, minimum, and average daily rates are 22.1, 8.4, 

 and 15.7 cc. The leaves of the tree tops are thus exposed to an evaporating 

 power of the air 6 times as great as that obtaining for the ground vegetation. 



The forester's part of the report contains many data of the distribution, 

 composition, volume, and rate of increment of these forests. The results 

 show that they may, when cut and logged by modern methods, make a very 

 important contribution to the lumber supply of the world. In this connection 

 it is interesting to note that the average rates of growth of the dipterocarps are 

 about the same as those of the hardwoods in the central deciduous forest region 

 of the United States; while one of the most rapid growers, Parashorea plicata, 

 appears to grow about twice as fast as Liriodendron. The relative advantages 

 of various cutting systems are discussed, and the opinion expressed that plant- 

 ing of dipterocarps is not likely to be successful. 



This article, together with the earlier reports of Whitford, gives a good 

 general ecological knowledge of these interesting forests, and should furnish 

 a good basis for the rapid evolution of methods of forestry which will render 

 these natural resources a permanent source of wealth for these islands. — 



Geo. D. Fuller. 



Distribution of species.— Willis in two recent papers 10 attempted to show 

 that the geographical distribution of species within Ceylon is to be explained, 



species 



Brown 



Phil. 



Jour. Sci. Sect. A. 9:413-561- figs. 16. 1914. 



9 Bot. Gaz. 58:193-234. 1914. 



10 Rev. in Bot. Gaz. 61:82. 1916; 62:160. 1916. 



