CHAP. III. NATURAL AND ECONOMICAL USES, 219 
and cultivated, there will not, we may presume, be that desire, which now 
seems to exist among botanists, to increase the number of species. Formerly, 
and more especially among the disciples of Linnzus, the great business of the 
botanist was to collect, name, and describe plants. These were then the 
highest departments of the science ; but, now, the anatomical, physiological, 
and chemical studies of plants occupy that station; and the naming and de- 
scribing of species is considered as comparatively mechanical. 
The other cause which has contributed to increase the number of supposed 
species is, the natural eagerness of botanical collectors, sent abroad in order to 
discover novelties, to find something new, in order to answer the end for which 
they were sent out. Thisis very natural: and where there is a strong desire for, 
and also an important interest concerned in, obtaining anything, either the thing 
sought for, or something like it, will be found. Hence the young and ardent 
collector will seize upon every variation produced by climate, soil, situation, 
age, or even accident, to add another specimen to his herbarium; which enables 
the botanist at home to add another name to the number of his species. This 
we believe to be much more frequently done from practical inexperience, than 
from any intention to deceive; so different is the appearance which plants pre- 
sent in a wild state and in a state of cultivation, and, often, in one country 
from what they do in another country; and so difficult is it to judge of an 
entire tree by a dried specimen, perhaps only a few inches in length. This 
state of things, in the comparative infancy of botanical science, is perhaps un- 
avoidable; and it is, doubtless, erring on the safe side, to collect and bring home 
every thing that can be at all considered as distinct, leaving it to cultivators 
and botanists to determine afterwards whether it is really so. It is proper, 
however, to notice this state of things, to aid in accounting for the present 
state of confusion and uncertainty in the names and characters of trees and 
shrubs ; and to show the little faith that is to be placed in botanical descrip- 
tions drawn up from dried specimens of any kind,and more especiallyfrom those 
procured by inexperienced collectors. If this may be considered as applicable 
to plants generally, it is more particularly so in the case of trees and shrubs; 
which, from the long period which they require to attain maturity, naturally 
assume very different appearances under different circumstances: and which, 
therefore, require to be studied, not only in the same locality, but in different 
localities, for a number of years, before any decided opinion can be pro- 
nounced respecting which are species and which are varieties. 
It will not, we trust, be supposed, from these observations, that we intend 
to set ourselves up as a model for imitation, in determining species and de- 
scribing them; on the contrary, we value the Arboretum part of this Encyclo- 
pedia much more, as containing only the names of such things as we know to 
be really distinct, and actually in existence in England, than for its pretensions 
in a purely botanical point of view. 
GELAP,, IH: 
TREES AND SHRUBS CONSIDERED WITH REFERENCE TO THEIR 
USES IN THE ECONOMY OF NATURE AND TO MAN. 
Tue large proportion which the ligneous vegetation of the earth’s surface 
bears to its herbage, and the immense extent of the forests in comparison with 
that of the meadows, pastures, or plains, which it contains, seem to indicate 
that trees and shrubs act an important part in the economy of our globe. 
In countries uninhabited by man, the influence of forests must be on the 
climate, on the soil, and on the number of wild animals and herbaceous 
vegetables. In civilised countries, to these influences must be added the 
