On Pruning Forest Trees. 
S93 
It now only remains to present the reader with one more extract, 
from the able work which has fiirnished those already laid before him ; 
I shall then endeavour to elucidate the striking facts recorded, by a 
cursory view of the structure of the vegetable organs, and of the 
agency of electric chemistry in the laboration of the juices, and the 
final developement of buds and branches. 
A fourth coiTespondent, has favoured Mr. Withers with a very con¬ 
clusive set of observations, on the effects of pruning the Black Italian 
Poplar; and he adds, “ Those observations have confirmed me in the 
opinion, that after the vessels of a tree are filled with sap from the 
roots in spring, every bud at the time that it shoots externally^ sends 
forth innumerable fibres downward^ between the bark and the wood,^ 
constituting, as it were, a number of independent plants, deriving 
their nourishment from the juices deposited there, (which may be com¬ 
pared to the chyle of the animal body) in the same manner as the 
whole tree derives its grosser nutriment ft om the earth; and that it is 
this constant accession of fibrous matter^ ivhich causes the increase of 
trees in bulkT 
In order to ascertain the causes of the injury that trees receive 
from the loppings and prunings of their branches, it will be needful to 
direct the reader’s attention, in the first place, to the origin and pro¬ 
gress of the buds or germs. Each bud may be considered as an entire 
system in itself, capable of becoming, under favourable circumstances, 
a complete plant or tree; it is separate, or independent of the parent, 
in as much as respects its individual constitution, but connected with, 
and dependent on that parent, as to its source, and medium of nutri¬ 
tion. I shall not here pretend to decide between the conflicting 
opinions of philosophers, as to the origin of buds. Du Hamel, con¬ 
cluded, that they existed in a pre-organised state, and were originally 
formed from the pith, because, “ having taken the trunk of a Lime 
tree, of about four or five inches in diameter, about the middle of 
which there was a bud ; and having examined the section with great 
care, he thought he could trace a ray, of a whiter shade than the rest 
of the wood, extending from the pith to the bud.” 
The author of a treatise on ^‘Vegetable Physiology,” published in 
the “Library of Useful Knowledge,” contends, that “every germ is 
a distinct insulated individual, the lateral progeny of the plant, gene¬ 
rated at the period of the developement of the stem, or the branch on 
which it appears as a bud;” that “all branches proceed from germs 
formed in the earliest unfolding of the parts in icJiich they appear, 
although the buds produced from these germs may not be ))rotruded 
until the tree be greatly advanced in age.” I'his writej- also has 
• Dr. Aikin, in bis “ Kalendar of Nature," advancea a siiuily; oniiiioii. 
VoL. I, No. a. 3 G 
