Dec. 1897.] BOTANICAL SOCIETY OF EDINBURGH 91 



35 years, after which the gradient becomes less, and after 

 50 years of age there is a considerable falling off, with a 

 slight increase, however, during the last 6 years. The last 

 increase in the gradient should be specially noted, as it 

 occurs in all the trees examined, but it will be discussed in 

 the second paper. 



The girth increase was most vigorous from 20 to 35 

 years of age, but good, sound growth was made up to 50 

 years of age. The tree was 6Q years old, and the total 

 girth of wood was 1695 mm., i.e. 5 feet 7f inches. 



B. Norway spruce (Picea cxcelsa, Link.) grew about a 

 furlong W. of A, on the same side of the road, but much 

 farther down the hill. It had trees all round, and the only 

 open aspect was to the N., where the ground sloped very 

 rapidly down to the Dee. 



The N". radius measured 201*5 mm. 

 „ S. „ „ 186-5 „ 



„ W. „ „ 178-5 „ 



„ E. „ „ 175-0 „ 



The girth curve shows at once that the conditions had 

 been less favourable for the spruce than the larch. 



The first 5 years' growth was slow, then came a more 

 rapid and almost uniform growth up to 30 years of age, 

 after which the gradient becomes smaller and smaller until 

 60 years of age, from which time until the tree was levelled, 

 at the age of 68, there was a slight rise. The total girth of 

 wood was 1165 mm., i.e. 3 feet lOf inches. 



C. Scots pine {Pinus sylvestris, L.) grew on the N.E. slope 

 of Craig Choinnich, a very steep wooded hill which rises 

 about a mile to the east of Braemar into a sharp peak, 

 176-J: feet above sea-level. 



Below the place where this tree grew, the public road to 

 Ballater, distant only a few yards, runs in an E.S.E. direction. 

 Trees grow down to the road, while close to the latter, on 

 the N. side, is the Dee, and beyond the river lie open 

 meadows. The open aspect was thus on the N.E. side of 

 the tree, and it is noteworthy that the N.E. radius was 319 

 mm. long, but this radius is not taken into account in 

 calculating the girth, as uniformity was desired in all the 

 calculations. 



