90 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



determined from normal yield-tables by using the formula 



2 . 



Other subjects coming within the purview of this branch of 

 Forest Management are silvicultural methods, the various 

 kinds of rotations, determination of the cut, and the working- 

 plan document, of which simplicity and brevity should be the 

 keynotes. In one of the several appendices to the book a 

 useful outline is provided for forest description. 



The last two sections of the book on Finance and Administra- 

 tion are less applicable to British conditions than the preceding 

 sections, but are also deserving of careful study. 



T/ie Practice of Silviculture. By Ralph C. Hawley. Pp. xi + 352. 

 London: Chapman & Hall, Ltd, 1921. Price 22s. 



In recent years we have been indebted to the staff of Yale 

 University Forestry School for a series of admirable text books 

 on forestry, and this volume is a valuable addition to their 

 number. 



In the opening chapter, the author defines silviculture as the 

 art of producing and tending a forest, or the application of the 

 knowledge of Silvics (forest ecology) in the treatment of a forest, 

 and indicates how he proposes dealing with the subject. "The 

 field of silviculture divides itself logically into three parts defined 

 as (i) treatment of the stand during the period of regeneration 

 or establishment; (2) treatment of the stand during that portion 

 of the rotation not included in the period of regeneration : a 

 consideration of intermediate cuttings; (3) protection of the stand 

 against injuries of many kinds." The more important of these 

 are fire, insects, fungi, animals, and wind. This subject leads 

 into various specialised fields such as fire protection, entomology, 

 pathology, and zoology. 



The second chapter is introductory to a study of the first of 

 these main subdivisions, and a detailed treatment of what are 

 described as the standard reproduction methods, the author 

 using this term in preference to the synonymous expression 

 " silvicutural system." " Many different reproduction methods 

 have been developed, but they can be reduced on analysis to 

 a few standard methods which are applicable in principle the 



