300 
DESCRIPTIONS AND 
are often seen and therefore referred to. In the beginning of the 
chapter on Shrubs, pages 455 to 459, are some remarks on the con¬ 
siderations which influence a choice of shrubs (some of which apply 
equally to trees), to which the reader’s attention is invited. 
Order of Arrangement.— It is extremely difficult to follow 
any system for the classification of trees and shrubs that will 
greatly facilitate the reader in finding readily what he wishes to 
read of, or that will save him constant references to an index. 
Botanical classifications, when thoroughly made, require quite too 
much familiarity with botany to give them any value to the mass 
of readers who know only the a, b, c’s of the science • yet they 
must, after all, be the ground-work of the most convenient arrange¬ 
ment for descriptions. Though the same botanical family—often 
the same species—has plants of every variety of size, from ground¬ 
lings to lofty trees, which differ from each other in their larger 
characteristics as much as from some members of other families 
with which they have little botanical connection, yet, in general,\ 
it will be found that grouping by botanical relationship brings together 
those which resemble each other in the greatest number of particulars. 
To classify trees and shrubs by their sizes, would separate 
family groups, and scatter them promiscuously among each other, 
while in all respects but size, their similarity of traits make it most 
easy to describe them by families. Take the oaks, for instance. 
The different species are numbered by hundreds, all having some 
marks of consanguinity in their general appearance, but quite 
diverse in forms and sizes. The immense variety of species of the 
first differ still more among themselves ;—varying in size from lofty 
trees to pigmy shrubs. If we class them with evergreen trees 
according to their varying sizes, they would become sadly mixed 
among the pines, junipers, arbor-vitaes, yews, and a score of newer 
evergreen families. If classified by forms alone, the same confusion 
would arise. It is best therefore to keep botanical family groups 
together. All oaks, for example, large and small, are described 
consecutively under the head of The Oak ; and as most of them 
are trees, they are described under the general head of Deciduous 
Trees ; though there are varieties which are really shrubs only. 
