CHAP. II. CONSIDERED BOTANICALLY. DET 
ters given of them in botanical works. The nicety of these distinctions has 
we know, deterred numbers from the study of practical botany ; and has pre- 
vented others, who have had the courage to proceed, from ever hoping to 
attain any satisfactory result. It has also (and this we consider to be the 
most important part of the evil) prevented many persons from forming col- 
lections of trees and shrubs, by inducing them to believe that such collections 
could never be made anything like complete, without incurring an expense 
greatly beyond what is really necessary. Instead of this being the case, the 
number of hardy trees and shrubs is so small, when compared with that of 
hardy herbaceous plants, or stove or green-house plants, that there cannot be 
the slightest difficulty in becoming acquainted with all the species, provided 
these and the varieties are only seen together; and the cost of as complete a 
collection of species as can be procured in the London nurseries is such as 
to be within the reach of every planter of the grounds of a villa of a single 
acre in extent. 
The mode by which we propose to attain these objects is very simple. We 
shall retain the botanical species and varieties in the catalogues, so far as we 
believe them to exist; but we shall, in every case, place before them the name 
of the aboriginal species to which they belong: for example, in the case of the 
genus Fraxinus, which, in our Hortus Britannicus, appears to consist of 41 
species and 12 varieties, we shall rank 30 of the species under the head of 
F. americana, two of them under the head of F. /entiscifolia, and the re- 
mainder under the head of F’. excélsior. It may be asked, whether it would 
not be better at once to make distinct genera of these three species? To 
which we answer, that it would not; because they are.all so obviously of the 
same general appearance, as evidently to belong to the same family. There 
would be the same objection to separating the oak family into different 
genera; though we think it highly probable that there are not a dozen abori- 
ginal species of oak in the world. Every division, or conglomeration, in botany, 
that can assist the mind to generalise, at the same time assists it in particu- 
larising; and it will be found much more easy, after throwing all the races or 
varieties of Fraxinus americana into one group, to distinguish them from each 
other, than by leaving them as distinct species, and having the trouble of dis- 
tinguishing them, not only from other races or varieties of #. americana, but 
also from all the races or varieties of F. excélsior. 
Such are the principles which we have adopted, to guide us in arranging 
species, races, and varieties, from a perfect conviction of their truth. If we 
had not had an opportunity of observing, for several years past, the collec- 
tions of trees and shrubs in the neighbourhood of London, and of studying 
them at every season of the year, with a view to the production of this 
work, we should never have been able to arrive at these principles, or to 
adopt them from others, with any degree of satisfaction to our own minds, 
We are, however, perfectly satisfied that we are in the right path; and we 
feel convinced that all practical botanists who have had an opportunity of 
making similar observations, and who have made them, will approve of our 
arrangement. 
Sect. III. Ofthe Mode of describing Trees and Shrubs. 
Ir is foreign to the object of this work, to enter any farther into botanical 
science than becomes necessary to elucidate the reasons which have in- 
duced us to depart, in any particular, from general practice. It will readily 
be conceived, from what has been stated in the preceding section, that we 
attach no great value to what are called the specific characters of botanical 
species; that is, of what we shall distinguish as races in some cases, and yarie- 
ties in others. The reason is, that we do not think it is often practicable to 
discover a species or race by such characters alone. The specific character 
of an aboriginal species we consider in a different point of view; for, as we 
