Nov. 1892.] BOTANICAL SOCIETY OF EDINBUllGH, 527 



2. CONIFER.E OF EeCENT INTRODUCTION. 



The valuable pai^er contributed to the Conifer Conference 

 of 1 8 9 1 by Mr. Malcolm Dunn, with tables giving the dimen- 

 sions of a vast number of the recently introduced Conifevie, 

 from information furnished to him by practical men in all 

 parts of the United Kingdom, is almost the sole source 

 of the details in the concluding division of my subject. 

 The mass of information contained in these tables is, I 

 believe, unrivalled for extent and accuracy. It might have 

 sufficed to select only the best example of each species, in 

 order to show the size which each has been able to reach 

 in Scotland under the most favourable circumstances, but 

 it seemed more advisable to take two or three of the best 

 in each species, as there was a risk that single examples 

 might be supposed to be altogether exceptional ; of course 

 none of these recently introduced species have had time to 

 prove what they can do in the way of producing giants in 

 this country, and our chief interest lies in showing the 

 extraordinary rate at which many of them have grown. I 

 have, therefore, added to my selected examples from Mr. 

 Dunn's tables a calculation of the rate of their girth- 

 increase ; and here we are on surer ground than when 

 dealing with long-established species, because, knowing 

 with certainty the date of their introduction, we are at 

 least sure that the existing examples cannot exceed a 

 certain age. In some cases, indeed, Mr. Dunn's informants 

 have themselves planted the trees of which they treat, and 

 in many others the date of planting has been accurately 

 recorded. There is a difficulty in interpreting the " Date 

 of Planting " in the tables, as it may mean either planting 

 of a seed or of a young tree of unknown size. But, I 

 believe, in the vast majority of cases, a seedling 18 inches 

 or 2 feet high is implied. To avoid exaggeration, however, 

 my calculations are all based on the supposition that the 

 trees when planted had reached 5 feet ; the height at which 

 all the measurements in Mr. Dunn's tables were taken. 



I. Dimensions of recently introduced Conifers, almost all 

 selected from information collected by Mr. Malcolm Dunn 

 for the Conifer Conference (Jour. Hortic. Society, 1891); 

 with the rate of their girth-increase. 



