PERIODICAL LITERATURE 85 



In the sixth year some more pruning of side branches may be neces- 

 sary. In the seventh to eighth year it often becomes necessary to re- 

 duce the number of larch where the oaks are suffering from their 

 shade ; sometimes a very severe pruning is all that is needed. In the 

 ninth year at least half of the remaining larch is removed, giving some 

 350 pit-wood poles per acre. The remainder of the larch are cut out 

 in the tenth and eleventh years, giving another 300 to 350 poles per 

 acre of rather larger size. At the present prices the return from these 

 early thinnings is not negligible ; and although a much larger return 

 could be obtained by allowing some of the larch to stand for three or 

 four years longer, this gain would be at the expense of the future crop 

 of oak and beech, which must suffer if any appreciable number of larch 

 are retained in the crop after the eleventh year. 



It is possible that some other kind of tree — for example, birch — 

 might possess all the other good qualities of larch as a nurse, but hith- 

 erto larch stands alone in the value of the early thinnings. 



One feature is noticeable in all the plantations described — the very 

 trifling extent of damage done by the larch canker and aphis. 



Recommendations regarding these operations by Professor Fisher in 

 1907 have been thoroughly justified by the result, both in the good 

 growth of the oak and beech and in the considerable return from the 

 early thinnings of larch. 



Transactions of Royal Scottish Arboricultural Society, July, 1918, pp. 173— I7f. 



MENSURATION, FINANCE, AND MANAGEMENT 



A set of interesting systematic increment mea- 

 Annual surements are published by Milne-Home, the 



and measurements having been made in several plan- 



Seasonal tations, six to eight years in succession. The 



Increment tabulation gives, besides the year of measure- 



ment and age of the plantation, the estimated 

 growing stock, number of stems per acre, average dimeter at 4 feet 6 

 inches high, per cent rate of growth, mean annual increment, current 

 annual increment. 



The percentage rate is figured by Schneider's formula! Unfor- 



nd 



tunately, a full description of the stands is not given, but from the 



statement of the number of trees it appears that we have in several 



cases to deal with rather open plantations, the numbers running for 



