1887-88.] Anmtal Increase in Girth of Trees. 



265 



Ahies Douglasii. 



Trustworthy average results cannot be derived from these 

 trees, as their history has been on the whole one of gradual 

 decline from an average increase in girth of 1-40 in 1878 to 

 0"25 in 1887. A severe depression took place in the first 

 of the three severe seasons, from which there was a gradual 

 but only partial rally up till 1882. In 1883 a fresh 

 severe fall took place, since which the increase has been 

 tritling. Both were handsome and vigorous-looking in 1878, 

 No. 10 in particular, the older of the two, being described as 

 " crowded with small long branches to the ground." Of this 

 tree we possess unusually full information. It must have 

 been planted soon after the introduction of the species in 

 1827 by Drummond, naturalist to the second Franklin expe- 

 dition (1825—27), as Loudon, in his Beview of the Botanic 

 Garden, ten years thereafter, gives its height as 8 feet, and 

 its girth, probably at or near the ground, as 9 inches. The 

 next recorded measurements were by Sir Eobert Christison in 

 November 1874 and March 1878, since when it was measured 

 annually till October 1887, when it was cut down. The 

 results are here given : — 



Thus the tree prospered exceedingly for about forty-five 

 years, its average annual increase in girth, at 4 feet 4 inches 

 from the oround, havins; been more than an inch and a half 

 for the last thirty-seven years of that period. In the next four 

 years the rate had fallen to three-quarters of an inch, but the 

 tree was stiU handsome and apparently in perfect health. 



