1886-87.] Monthly Increase in Girth of Trees. 



57 



grow more vigorously in the earlier months of the season 

 than the older trees. 



Thirdly, even as regards the species experimented upon, 

 the results are much more reliable in some than in others, 

 partly because of the varying number of trees measured in 

 the different species ; partly because, from roughness or 

 liability to scale in the bark, some species were not so eligible 

 for measurement as others ; and partly because individual 

 trees proved, for various reasons, to be indifferent growers, 

 and therefore were probably in an abnormal condition. The 

 degree of confidence that may be placed in the results obtained 

 in the various species will be indicated in the sequel. 



Monthly Percentage of Increase in Girth in different Species of 

 Deciduous Trees, hascd on four years' measurements (only 

 three for Septemler). 



Remarks. — The species are arranged in this Table in the 

 order of their vigour in the latter part of the growing season. 

 In the following remarks the girth of the trees is given as on 

 October 1887. 



Beeches. — Girths, 64, 66, 70, 78, 80, 81, 100, 121, 138 inches. 

 The most reliable of all the species observed. Nine speci- 

 mens were tested, all healthy to the end, and the smooth- 

 ness of the bark in this species ensures a degree of accuracy 

 unattainable with most other trees of similar age. 



Hungary Oaks. — Girths, 26, 30, 40 inches. Also very 



