IMPROVEMENT OF PLANTATIONS. 595 
ARTICLE XII. 
ON THE IMPROVEMENT OF THE FOREST TREE PLANTATIONS, 
(third paper,) 
By the Author of the Domestic Gardener^s Manual. — C.M.H. S. 
Gentlemen. — In order to render that which remains to be said 
upon this subject as perspicuous as possible, I must request your 
readers to re-peruse the few observations that have akeady been made 
upon the formation and developement of the buds or gems of plants, 
at pages 393 and 394 of the Horticultural Register. It may now 
be further remarked that many plants, particularly those of tropical 
climates, are said to be unfurnished with buds, " the leaf being in 
them, immediately protruded from the bark." Perhaps, however, 
buds, or embryons, tantamount to buds, must be admitted to exist in 
every plant ; for, how otherwise could there be a developement of new 
parts ? The enquiry into this physiological fact is very important, 
but not immediately connected with the subject imder consideration; 
it will suffice to observe, that buds, where they are visibly present, 
are generally found to be seated at the axillag of the leaves, that is, at 
the angle formed by the base of the leaf stalk, and the stem or branch 
from which the leaf emerges. Whatever be the precise nature of 
the bud or embryon, from which the future developement proceeds, 
certain it is that the bud has its origin and support in juices which 
have been prepared by those leaves that had previously existed ; and, 
therefore, to the agency of the leaves must be ascribed the com- 
mencement and future support of all the vital functions. 
If the reader bears in mind that the leaves are proved, by a thou- 
sand facts, to be the organs of respiration, the laboratories in which 
that immature fluid, familiarly known by the appellation of Sap, is 
subjected to the stimulus of light and of air, he will be naturally pre- 
pared to ascertain, as far as may be possible, the nature of that fluid, 
and the course or channels by which it is conveyed from the fibrils 
of the roots to the extremity of the leaves. 
The Sap, in the common acceptation of the term, is that simple 
bland fluid, which is absorbed from the soil, and supposed to be dis- 
tributed by appropriate vessels throughout the whole vegetable struc- 
ture. This fluid was, at a former period, believed to circulate in the 
vessels of the plant ; and hence the origin of the expression so often 
misapplied, " the circulation of the sap." There is reason, however, 
to believe that, strictly speaking, the sap does not circulate, that is, 
in a way corresponding with that of the motion of the blood in ani- 
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