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TRANSACTIONS AND PROCEEDINGS OF 



[Sess. 



II. Monthly Eesults. 



A. History of the Species, 



(1) Deciduous Trees. 



Betula alba. 



The p.c. of girth-increase in the lialf-seasons in the two 

 young trees was ahnost identical, the amount in each half 

 in both trees being all but equal. Very different was it 

 with the old Birch, in which the proportion was as 27 to 

 73. 



In the young trees the increase was distributed over the 

 mouths in the average proportion for Deciduous species, but 

 the old one showed no increase at all in April, May, or 

 September, during six years' observation. The best month 

 in the young trees was June, with an average annual 

 amount of 0*30 and 0-3.2 ; but July was best in No. G* with 

 0-23. 



If these contrasts are due simply to difference in age, 

 they illustrate how extreme the differences may be between 

 young and old trees of the same species. No. G* was 

 quite healthy, and for six years grew at the probably fair 

 rate for so rjld a tree of nearly half an inch. 



