Mak. 1892.] THE BOTANICAL SOCIETY OF EDINBURGH. 261 



The following I'apers were read : — 



Observations on the Increase in Girth of Young Trees 

 IN the Eoyal Botanic Garden, Edinburgh, for Five Years 

 ending 1891. By David Christison, M.D., President. 



CONTENTS OF THE PAPER. 



PAGE 



Intuoductouy, ....... 262 



I. Annual Results, ...... 264 



A. History of the Species, . . . . ,264 



1. Deciduous Trees, ..... 204 



2. CONIFERiE, ...... 273 



B. Collective Results, . . . . . .279 



1. Deciduous Trees, ..... 279 



a. Comparative annual I'ate of the species, . . 279 



b. Range of girth-increase in the five years, . . 282 



c. Maximum annual growth in the species, . . 282 



d. Annual variation in aggregate girth-increase, . 282 



2. CONIFERiE, ...... 283 



a. Comparative annual rate of the species, . . 283 



h. Range of girth-increase in the five years, . . 285 



c. Maximum annual growth in the species, . . 285 



d. Annual variation in the aggregate girth -increase, . 286 



Comparison of the Annual Variation in Girth-Increase 

 OF the Deciduous and Evergreen Classes, . . 286 



II. Monthly Results, ...... 288 



A. History of the Species, ..... 288 



1. Deciduous Trees, ..... 288 



2. CONIFERiE, ...... 299 



B. Collective Results, . . . . . .303 



1. Deciduous Trees, ..... 304 



a. Monthly amount of girth-increase in thirty young 



deciduous trees, individually and collectively, . 304 



b. Monthly proportion of giith-increase in thirty 



deciduous trees, collectively, . . . 309 



c. Monthly proportion of girth-iucrease in deciduous 



trees, individually, . . . .310 



d. Distribution of girth-increase over the grow^ing 



season in the younger group of deciduous trees, . 313 

 Disti'ibution in the genus Quercus. . . 314 



e. Proportion of girth-increase in the first and second 



half seasons in deciduous trees, . . .315 



2. CONlFElt^, ...... 319 



a. Monthly amount of girth-increase in twenty Coni- 



ferse, individually and collectively, . .319 



b. Monthly proportion of girth-increase in twenty 



Conifera^, collectively, .... 323 



c. Monthly proportion of girth-increase in Coniferous 



species and trees, individually, . . 325 



d. Distribution of girth-increase over the growing 



season in the younger group of Coniferfc, . 327 



Retardation of girth-increase in mid-season in 



certain Conift^rfe, .... 328 



e. Pro]iortion of girth-increase in the fir»t and second 



half seasons in the Conifers, . . . 328 



III. General Remarks, . . . . .330 



