INFLUENCE OF CLIMATE ON VEGETATION. 
201 
connected with the subject, may be instrumental in inducing many to plant largely of this 
interesting tribe, and when about to do so (whether they intend to complete at once their 
arrangement, or it be done progressively), that they may lay down some well-digested plan 
by which to be guided, and which may ultimatively form a perfect and harmonious whole, 
that will redound to the credit of its projector and the " glory of the gardens," of the 19th 
century ; as much as the Evergreens at Woburn do to the honour of the noble Duke who 
planted them. " The inequality and variety of surface, together with the different species 
of trees and shrubs by which it is decorated, render this one of the most interesting 
landscapes in the country." — (Forbes in Hortus Woburnensis), and it is perhaps the 
grandest monument which could have been raised to the patriotism and liberality of that 
high-minded nobleman. 
INFLUENCE OF CLIMATE ON VEGETATION. 
By Mr. Moore. 
The influence of climate on the development of vegetation, though not alone dependent 
upon the atmospheric temperature, is yet largely effected by it, for we know that a certain 
degree of heat is essential to the well being of every vegetable. That essential amount of 
heat is found to be variable in respect to different species of plants, depending in a great 
measure on their natural distribution over the surface of the earth ; for as the natural tem- 
perature is greater at one place than at another, so has it been wisely provided, that the 
vegetation which exists naturally in every place is adapted, so to speak, for the climatic 
conditions which there exist. It is because this is so, that a knowledge of the conditions 
under which a plant is placed in a state of nature, becomes so essential to the cultivator, 
who can have no surer guide as to the constitution of the objects of his care. There are, 
indeed, some few species of plants which are found widely extended over the earth, and 
under conditions extremely different; but these are exceptions to the rule, and consist 
chiefly of that class of subjects which seem to follow the steps of man wheresoever 
he goes. 
Now, it is not because temperature constitutes climate, that it has been taken as the 
index to the climatic conditions which exist over the earth's surface, but because it is the 
most tangible element of climate. It cannot be said to be the most important element, 
because a due proportion of the other elements are equally essential ; but, apparently from 
custom, there seems to exist a disposition to look upon temperature as the leading feature 
of those conditions, which constitute what we call climate ; and so that this position is 
understood, there can be little practical objection to the viewing of it in this light. There 
is indeed some advantage in this, since thermometers are common and well understood 
instruments, and a large amiount of information concerning the climate of almost every part 
of the known world exists, based on the variations of temperature, that is to say, moulded 
, to this fashion which popular will has approved. 
Hence, though the cultivator may be warned against looking too much to the tempera- 
i ture of his artificial climates, to the neglect of moisture and the admission of light, it does 
seem desirable to bow to the popular notion, and continue the elements of temperature as 
the convenient index to the more bulky materials of the subject, if it be only to avoid 
unnecessary intricacy. 
I I have already observed (p. 15), that the existing conditions of natural climate as to its 
I temperature, render it obvious that a greater variety of artificial climate than is at present 
generally afforded, is required to cultivate successfully the different kinds of exotic plants 
' which have been introduced to our gardens from every part of the world. Though the 
whole world has contributed to the number of objects of cultivation, yet are they generally 
1 classed into three groups, a number altogether insufQcient to lead to the recognition of that 
! variety of artificial climate which is essential to their well-being. 
Under this impression, I have recommended that the old titles of "stove" and "green- 
VOL. I. — NO. VII. D D 
