xil EXPLANATORY REFERENCES. 
EXPLANATORY REFERENCES. 
Tue greater part of the letterpress of this Work consists of the descrip- 
tion, history, geography, uses, propagation, culture, &c., of the species and 
varieties of the trees and shrubs cultivated in the British Islands; and this is 
always printed in type corresponding in size with that used in this sentence. 
The short descriptive notices of species and varieties which it would be 
desirable to introduce, of such as have been introduced and lost, of such as 
have not been seen by the author, even though mentioned in British catalogues, 
and of such as are half-hardy in the climate of London, or supposed to be so, 
are uniformly printed in a smaller type. 
The statistics, or accounts of the dimensions of trees, which we have 
received from different parts of the British Islands or the Continent, are also in 
small type, in order to save room. 
The portraits of trees which form the last four volumes are sometimes, 
referred to as in the second volume, and sometimes as in the last volume. 
These references were made under the idea of binding up all the letterpress 
in one volume, and all the plates in another, which, now that the Work is 
finished, is found to be impracticable. The readiest way of finding the portrait 
of any particular species of tree is, to refer to the Alphabetical Index of 
Portraits of Trees, given at the end of the eighth volume. The readiest way 
of finding the description and history of any particular species or variety, and 
of ascertaining whether or not a figure is given of it, is by referring to the 
general Alphabetical Index, at the end of the fourth volume. 
In various parts of the Work reference will be found to Part IV., and to 
the Encyclopedia of Arboriculture. These two references refer to one and 
the same work, viz. the Encyclopedia of Arboriculture, which it was originally 
intended to include in the Arboretum Britannicum, but which, for the reasons 
stated in the Preface, will now be published separately in one volume; and 
in which the subject of trees and their culture will be generalised, and their 
mode of treatment given en masse, whether as seedlings in the nursery, as 
useful and ornamental plantations, as yielding timber and other useful pro- 
ducts, or as ornaments in the lawn and shrubbery. 
The engravings of the botanical specimens, whether printed along with the 
text, or along with the portraits of the trees in the four last volumes, are 
invariably to one and the same scale of 2 in.to 1 ft. Where any portion of 
the plant is given of the natural size, it is distinguished by a cross, thus, +. 
Where dissections are given, m. signifies male, f. female, and mag. magnified. 
The portraits of the entire trees and shrubs given along with the text are 
to different scales, which are always indicated in the descriptions: they are 
chiefly 1 in. to 12 ft., 1 in. to 24 ft., and 1 in. to 50 ft. 
The portraits of the trees in the last four volumes are nearly all from in- 
dividuals that were growing within ten miles of London, in the years 1834, 
1835, 1836, or 1837. These portraits are chiefly of young trees, of ten or 
twelve years’ growth, and are drawn to a scale of 1 in. to 4ft.: but there 
are also portraits of full-grown trees, of all the principal kinds of which 
full-grown specimens are to be found within ten miles of London (taken 
chiefly from Syon), and these are drawn to a scale of 1 in. to 12 ft. 
Of some species of trees good full-grown examples could not be found 
within ten miles of London; and- of these portraits have been taken from 
trees growing in different parts of Great Britain (particularly from Studley 
Park and Dropmore) and Ireland, and, in one or two instances, from trees on 
the Continent. 
The botanical specimens of the young trees exhibit a branch in flower, the 
winter’s wood when the tree is deciduous, anda branch with ripe fruit, and with 
