Periodical Literature 401 



not be followed. The distinction between intermediary and final 

 yield also is declared undesirable. 



He then points out that Mantel's formula corresponds to his 

 requirements, but only if for extensive districts one and the 

 same r is arbitrarily and unalterably fixed, when the expression 

 becomes a real constant with which out of the stock on hand 

 budget, and with time actual, increment may be determined. 



For practical purposes this is all that is necessary, whatever 

 statistics may be gathered for scientific purposes by Experiment 

 Stations. 



For the determination of the stock on hand, however, he 

 advocates the use of yield tables, provided many height measure- 

 ments are being made to test their applicability. It the latter is in 

 doubt, let the experiment station decide the proper per cent of 

 addition or subtraction, which is then also to be considered a 

 constant. Finally, the stock of the older age-classes should only 

 be used for the yield regulation, which permit of direct measure- 

 ment. He objects to ocular taxation. 



Einiges iiber Forsteinrichtung. Schweizerische Zeitschrift fur Forstwesen, 

 March to April, 1915, pp. 41-44. 



We have regretted all along that lack of 

 Determination space has prevented us from briefing fully 

 of the the critical discussions by Dr. Martin, 



Rotation which have for some time been running in 



the Tharandter Jahrbuch under the title 

 "The Economic Problems of Forest Management, with Special 

 Reference to the Prussian State Forests." While they do not 

 bring anything especially new, they are classical in expose, re- 

 plete with information, logical in their philosophy and unusually 

 simple and clear in style — a rarity among German writers on 

 forestry — so that a close study of them may be set down as an 

 excellent course on forest management. In the last two (sixth 

 and seventh) chapters, running through three numbers on 95 

 pages, the author continues the discussion of the problem of de- 

 termining the rotation and the organization of a working plan's 

 bureau, the author being an advocate of such in preference to 

 leaving the work to the supervisors. 



