REVIEWS 707 



"On areas as well stocked with reproduction as those covered by the 

 study the comparatively small amount of scattered injury which results 

 when the stock is carefully managed can hardly be said to represent a 

 tangible loss of value." 



Then, without very convincing basis for the valuation, he continues : 



"If seed trees are present in sufficient quantity to reseed the area, the 

 loss will equal the value of the growth already made by the seedlings, 

 which at lO years of age will be approximately 30 cents per acre, or 

 $0,001 per tree if there are less than 300 seedlings per acre, and at 20 

 years 75 cents per acre, or one-third of a cent per seedling where there 

 are less than 250 per acre. These values, which are based on an aver- 

 age annual increment (for a 150-year rotation) of 100 board feet per 

 acre and a stumpage price of $5 per 1,000 feet, are liberal. With an 

 average annual increment of 200 board feet, which may be possible on 

 the best sites, the loss would be 60 cents and $1.50 per acre at 10 and 

 20 years. . . . 



"Benefits to the forest resulting from the use of the range may often 

 offset the slight damage done by regulated grazing. These benefits may 

 consist in direct aid to forest reproduction or in lessening the danger 

 of serious fires. . . . 



"The value of sheep-grazing in helping tree reproduction to start is 

 frequently overestimated. It does result in more abundant germina- 

 tion under certain conditions, viz., in case of heavy grazing on poor 

 sites." 



The author then elaborates the proper methods of handling the stock 

 to insure least damage. 



B. E. F. 



A Note on Tliitsi, M elanorrhooa usifafa, JValL, zvith Special Refer- 

 ence to the Oleo-resin Obtained from It. By E. Benskin and A. 

 Rodger. Indian Forest Records, Vol. VI, Ft. III. 1917. Pp. 97-127. 



This publication takes up the description of the tree, its common 

 names, distribution (with map), a brief discussion of its reproduction, 

 and the timber it produces. The method of tapping for oleo-resin is 

 described and the costs, yields, and experiments to improve the quali- 

 ties of the product are discussed. 



The tree, discovered by Dr. Wallich in 1828, is found with Diptero- 

 carps and other species that thrive on the drier forest soils of Burma, 

 at an altitude of about 3,500 feet. It occurs plentifully over an area 

 of more than 5,000 square miles and is found scatteringly over nearly 



