110 JOURNAL OF FORKSTRY 



and other tropical woods, that will go far toward insuring a steady 

 supply of these timbers for future generations. 



One criticism that the reviewer has of this bulletin is the attempt that 

 has been made to compare the forest formations with those of similar 

 formations in other parts of the world. Such an attempt is more than 

 likely to fall short of the truth, especially when the author has not had 

 an opportunity to study those of other tropical countries. 



H. N. W. 



Statistics Compiled in the Office of the Silviculturalist , Forest Re- 

 search Institute, Dehra Dun, During igi^-i6. The Indian Forest Rec- 

 ords, Vol. VI, Part II, 1917. 



The compilation of statistics relating to the growth and yield of 

 Indian trees, although begun in India a number of years ago, lacked 

 continuity and uniformity in the methods of measurement. In 1913 

 the board of forestry considered methods and forms, and since then the 

 methods of measurement have been more uniform. There have also 

 been more uniform methods in the tabulated data. Even yet, however, 

 lack of continuity and uniformity exists, making it impossible to utilize 

 much good work. 



Experience in India indicates that growth and yield studies require 

 the appointment of special offices to establish, supervise, and maintain 

 sample plots and experimental areas. This work has been the function 

 of the silviculturist, but it is impossible for one officer to supervise and 

 control sample plots throughout India, and the appointment of a special 

 officer in each province is highly desirable, owing to the urgent need of 

 extending silvicultural research. 



In the publication under review the statistics on growth and yield 

 have been computed from the following sources : 



(a) Periodical girth measurements of selected trees, recorded in reg- 

 isters by divisional forest officers ; the registers have been sent to the 

 silviculturist, the trees have been classified into girth classes, the aver- 

 age increment for each girth class calculated, and curves prepared for 

 each sample area; from the curves the girth for each lo-year period 

 has been read off. 



(b) Outturn registers of individual trees maintained by divisional 

 officers. After classification into girth classes, averages have been cal- 

 culated for each coupe. The yield of each tree is entered in the register 

 by a clerk on the spot as conversion is effected. Little supervision is 

 possible, and the accuracy of the entries for any single tree or even for 



