June 1892.] THE BOTAXICAL SOCIETY OF EDINBURGH. 443 



second year. The last measurements were made in October 

 1890, when the trees were 106 years old. Six of the 

 marked trees were unfortunately cut down, but the results of 

 the experiment, as shown by the measurements of the eight 

 surviving trees, are very remarkable ; they are as follows : — 

 The average girth of two trees transplanted at 16 years of 

 age was 89 inches ; that of three trees transplanted at 23 

 years of age was 88 inches ; but the average girth of three 

 trees left in the nursery was only 58^ inches. It 

 will be observed that when the measurements were first 

 recorded, the average girth of the transplanted trees was 

 considerably less than that of the trees which were left, 

 and which have now been so far distanced by them. It 

 is possible that the latter had not so much room and light 

 as the former, and it is probable that this was the case for 

 some years at any rate ; but the record is one of great interest. 

 Sir James Campbell observes that " at this rate of progres- 

 sion it is not too much to expect that transplanted oak-trees 

 will come to maturity 50 years sooner than non-trans- 

 planted trees." 



These results led him, in 1861, to undertake a second 

 experiment " to test the value, if any, of merely lifting the 

 trees and replanting them in the same holes without change 

 of soil or situation, and without giving increased space." 

 In 1861, the aggregate girth of six lifted trees was less i3y 

 2^ inches than that of six untouched trees ; but, in 1886, 

 the former had equalled the latter, and in 1892 had sur- 

 passed them by 5| inches. Should the increased rate of 

 growth of the lifted trees be maintained, the experiment 

 will prove a most noteworthy one. I understood Sir James 

 Campbell to say that the cost of lifting the trees, which, in 

 1861, were 25 years old, was not more than threepence 

 each. 



In connection with this question, I may mention the 

 difficulty I have experienced in taking accurate girth - 

 measurements of any but young trees with smooth bark ; 

 for where the bark is rough, and in process of scaling off, 

 there is not only a liability to actual change of girth, due 

 to the expansion or the falling off of bark-scales, but it is 

 exceedingly difficult, when measuring over the rough surface, 

 to arrive at exactly th,e same figure twice in succession, 



