PKRI(1!)IC.\T, T.lTlvRATURK 1043 



Larix Icptolcpis is adapted for planting in southern Sweden. It ex- 

 hibits very rapid height and volume growth, though the rate of growth 

 begins to decrease at a much earlier period than in the case of the two 

 larches previously mentioned. It is also subject to attacks by "cancer." 

 It is less intolerant of shade than the other larches, but on account of 

 its bushy crown is troublesome in mixed stands. Larix Icptolepis is 

 therefore only suitable for planting on good soils where a large volume 

 production must be obtained in a short time, though the timl)er is not 

 as valuable as that of the other larches. 



Larix occidentalis is similar to Larix europece and Larix siberica. 

 It is also subject to "cancer" attacks. Careful handling is advisable in 

 planting this tree in Sweden. 



B. L. G. 



Ldrken och dess hetydelsc for svensk skogshiishallning, Skogsvardsforeningens 

 Tidskrift. April-June, 1917, pp. 447-707. 



SOIL, WATER, AND CLIMATE 



Foresters and botanists in the United States 

 Toxic are not in accord on the effect of toxic soil con- 



Atrophy stituents as a cause of soil exhaustion. In the 



article under review, the Rev. E. A. Woodruffe- 

 Peacock states that "soil exhaustion, so far as forestry is concerned, is 

 that a woodland of one species cannot grow forever on the same spot, 

 but will sooner or later fail to renew itself on account of some action 

 vital to itself which it has upon the soil." The author contends that 

 the exact reason why this is so demands careful study, although here- 

 tofore it has eluded the most searching analysis. In the discussion of 

 soil exhaustion he calls attention to the following four points : 



(i) The failure for the time being of some soil constituent generally 

 found in soils. 



(2) The absence of the beneficial help of friendly bacteria and the 

 overabundant presence of inimical ones. 



(3) The presence of the mycclia of fungi around the roots of seed- 

 lings and of young trees on woodland soils. 



(4) Toxic materials, the products of decay, left by species on and in 

 the soil. 



The author contends that soil exhaustion is not caused by (i), as 

 only small quantities of soil constituents are used in tree growth, and 

 they are always found in abundance where a species is failing from soil 



