FORESTRY. 43 



conditions will not prevent the normal leaf fall. The cause of the leaf fall, 

 which ai)i)ear.s to lie in part at least within the plant, has nut been thus far 

 deterniined. 



On the periodicity of central European deciduous trees in the mountain 

 climate of Ceylon, II. Dingleu (Sitzher. K. Bayer. Akad. Wiss., Hath. Pliys. 

 KL, 1911, A'o. 2, pp. 2n-2J{7). — In connection with the above investigation the 

 growth performance of a number of deciduous forest and fruit trees, native to 

 Central Europe and growing at Nuwara Eliya and Ilalvgala in the mountains 

 of Ceylon, was observed. 



From the data thus far secured the author is led to conclude that the 

 temperate climate trees, when thus transferred to the tempered tropical 

 mountain climate at the above named places, make 2 growth cycles in a year 

 with little, if any, resting period between. The first cycle commences in spring 

 and ends in fall, at which time the trees recommence their life activities 

 almost immetliately, the cycle ending by spring. The leaves from the summer 

 growth are carried over into the late winter, wlien conditions seem favorable 

 for their falling off without at the same time seriously retarding the develop- 

 ment of the new growth. 



This continuous growth performance, however, appeared to weaken the re- 

 r.roductive activities of both the forest and fruit trees observed. Many kind.s 

 of trees matured their fruit but the yield was much less than in their native 

 land. Vegetative development was greater in a number of cases, as with oaks, 

 pears, cherries, and to a certain degree peaches, and less in other cases, such 

 as the red beech and birch, than in the natural habitat of these ti'ees. 



It is stated that no conclusion can be drawn as yet from the information 

 at hand as to the cause of this variation. 



The strength, elasticity, and other properties of New South Wales hard- 

 wood timbers, W. H. Warren {Sydney: Dcpt. Forestry, N. S. Wales, 1911, pp. 

 100, pis. 16, flys. 67). — This report gives the results of the following tests com- 

 menced in 1907 and continued up to December. 1010: Compression tests of 

 cubes to determine any variation in strength of wood growing at different 

 heights above the ground: the strength and elasticity of large^ind small timber 

 beams; the strength and elasticity of long and short columns subjected to com- 

 pression; shearing and tensile strength of timber; the holding power of nails 

 and spikes; the compressive strength across the fiber; hardiless and torsion 

 tests; resistance to wear in floors and street pavements; impact; and tests of 

 beams. The tests were made on various eucalypts, as well as with the turpen- 

 tine tree (Syncarpia laurifolia), brush box (Trlstania eouferta), and the 

 colonial teak (Flhulcrsia australis). The testing methods are fully de.scribed 

 and the results are tabulated and further explained by numerous diagrams 

 and illustrations. 



A careful consideration of the results obtained from the tests of cubes taken 

 from 5 sections of the tree shows that with the same moisture content present 

 in each case, the timber cut from the highest section is slightly, but not 

 materially, stronger than that cut from the other 4 sections. Each timber was 

 found to have a characteristic strength moisture curve beyond a certain point 

 in which additional moisture does not seriously reduce the strength. Diminu- 

 tion of moisture below this point, on the other hand, protluces an important 

 increase in strength, which is much greater in some timbers than in others. 

 The results illustrate the importance of seasoning on the strength of timber 

 and also indicate that certain timbers exposed to the weather may become 

 considerably reduced in strength. 



Hevea brasiliensis, G, Vernet (Bui. Econ. Indo-Chine, n. ser., IJf (1911), 

 Nos. 92, i)p. 777-826.; 93, pp. 917-9U; 15 {1912), No. 94, pp. 40-98, figs. 7).— 



