1887-88.] Annual Increase in Girth of Trees. 253 



Three species of oak, besides the native one, were tested, 

 but, as the number of trees was small, I have grouped them 

 together in one table. 



Quercus confcrta. — Three specimens were observed, but 

 only one for the whole decennial period. They are all 

 favourably situated in the lower ground of the Botanic 

 Garden, standing quite free from neighbours. They are 

 among the earliest trees in the Garden to put forth their 

 leaves. In 1880 No. 40 was in full foliage on the 15th 

 May, and in 1882 the buds were bursting on the 27th March. 

 All three have had a perfectly healthy appearance during the 

 whole period except one, whose leaves on the west side were 

 dried up and withered looking in the dry summer of 1887, 

 without, however, in the least prejudicing the girth-increase. 



The annual rate of increase, 1'60, is considerably greater 

 than in any other of the tested deciduous species. More- 

 over, No. 54, alone of all the trees under observation, deci- 

 duous or evergreen, at the Botanic Garden or Craigiehall, 

 attained the distinction of increasing as much as 2 inches 

 in one year. 



The rate of wpicarcl groivth in No. 40 was ascertained to 

 be a little above 7 inches annually for nine years, the height 

 having been 23 feet 5"5 inches in spring 1879, and 28 feet 

 9-5 inches in autumn 1887. 



The range of the individual increase has been moderate. 

 It was greatest in No. 54, the figures being 2'05 and 110. 

 The aggregate range (5"40 to 3'60) during the eight years, 

 when all the three trees were under observation, was also 

 moderate. 



So far as the data go, there is every reason to believe 

 that 1880 was the only year in the first depression that 

 had any marked effect on the increase. The falling off 

 was comparatively slight, particularly in No. 40, and re- 

 covery was complete in 1881.^ It is remarkaljle that in 

 both the subsequent principal years of general depression, 

 1883 and 1887, the increase in this species was considerably 

 above its average. 



* Apparently this species is remarkably hardy — hardier even than onr 

 native oak ; and for this reason, as well as on account of its rapid growth, 

 deserves patronage as an ornamental tree. The only objection to it is its 

 bushy, uninteresting form, at least as a young tree. 



