46 
PLANTING AND MANAGEMENT OF TIMBER. 
keeping for that. We repeat that it is widely 
different in the case of fruit trees ; every year 
repays the trouble of artificial planting, and if 
they required to be renewed at the end of ten 
years, still would it be worth the toil and 
expense. But there are other cases in which 
planting artificially may be desirable ; namely, 
in parks and ornamental grounds. The effect 
has to be produced, and it is as necessary to 
prepare the ground properly, at whatever cost 
may be required, as it is to prepare the foun- 
dation of the mansion properly to carry the 
superstructure. But for planting on a large 
scale artificial soil is out of the question, be- 
cause it is but little use to secure the first 
ten or fifteen or even twenty years of health, 
if it must be followed by canker and decay. 
There is no difficulty in determining as to the 
choice of trees ; but let them have no manure, 
no driving, no temporary excitement ; let the 
ground be loosened, and indeed trenched, if 
it will bear the operation, whether the trees 
chosen be elm, oak, plane, chestnut, birch, the 
firs, or any other, or a mixture of all ; have 
the plants small, for one of the worst errors 
committed in forcing plantations is the plant- 
ing of trees too old for the'purpose. The dis- 
advantage of too large a plant is great. In 
the first place, it is sure to have suffered more 
in the moving ; in the second place, it must 
be staked, or it will be disturbed by the first 
slight breeze ; in the third place, there is 
more labour attached to the work in any 
stage. It is impossible not to foresee all these 
things ; but there is yet another disadvantage 
worse than all, the losses by failure in the 
growth ; the two-year old seedling would, in 
time, overtake the very best of the plants 
moved at a greater age ; small plants come up 
with good roots, they are not affected by the 
wind, they begin to grow directly because they 
receive no check, and they are in every way 
likely to make better plants and better timber. 
Connected with this subject we subjoin a sj's- 
tem of arboriculture, and especially of pruning, 
by Mr. Gavin Cree, whose experience is equal 
to that of any man in the United kingdom. The 
subject is treated scientifically, and as such, may 
be studied with advantage. Mr. Cree says, — 
Scientific arboriculture may be defined, 
"The culture of wood conducted on physiologi- 
cal principles, or a knowledge of the organs 
which constitute the internal and external 
structure of trees, and of the various functions 
these organs perform through the instrumen- 
tality of external agents." These are generally 
treated as if they were inorganic matter, they 
are operated on as the ploughman operates on 
the ground, or as the carpenter or blacksmith 
on the wood or iron under their hand. Many 
eminent men have written treatises on vege- 
table anatomy and physiology, and many have 
promulgated their sentiments on the pruning 
of forest trees, while neither party understood 
how the science of vegetable physiology ought 
to direct the mechanical operation of pruning, 
so as to make it affect, to the greatest extent, 
the growth of the tree. There is in trees as 
in animals a vital power which presides over 
all their functions. This power is the agent 
by which the ascent and descent of the sap is 
produced, and certain internal and external 
causes facilitate the exercise of the phenome- 
non. Among the external are to be ranked 
the influence of air, heat, light, and moisture ; 
and it is to be admitted that there is strong 
attraction between air and water ; for no air is 
found without water, and no water without 
air ; and the system of operating on the 
lateral branches by shortening them. I shall 
give an outline of the principles which led me 
to the conviction that the system of pruning 
by shortening the lateral branches, which I 
brought forward a number of years ago, is 
calculated more than any other system to 
secure for the benefit of the tree an extra 
nourishment. The organs of nutrition or 
vegetation have one common object, to support 
the life in the vegetable, and the powers of 
these organs may be greatly increased by 
mechanical means. In order to use these 
means in a way to assist nature, some know- 
ledge of the physiology of plants is requisite ; 
the director or operator must understand how 
the organs exert their functions, otherwise he 
cannot reasonably expect to be successful. 
The different processes of the sap or vegetable 
blood must especially be carefully studied, as 
by it the growth and vigour is sustained. The 
sap is acquired and influenced in diverse ways. 
In spring, the small spongelets or extre- 
mities of the roots absorb the fluids and gases 
from the soil, which are conveyed by an in- 
herent power depending on the life of the 
tree ; or, more properly, the ascending sap is 
acted on through the roots by atmospheric 
pressure, up through the capillary tubes till 
it reaches the extreme ramifications of the 
stem, shooting forth buds and expanding 
The common sap having extended over all 
the branches, it mingles with the fluids ab- 
sorbed by the leaves, and losing the watery 
and aeriform principles which are useless for 
nutrition, by evaporation, it returns down the 
vessels of the bark, and in its course deposits 
cambium, which forms the annual rings of 
wood which extend to and strengthen the 
extremities of the rootlets, whereby they are 
made to extract more nourishment from the 
soil through the season ; and as the two saps 
commingle in the leaves, the descending sap 
which has not been deposited, in like manner 
mixes with that extracted by the rootlets, and 
is again carried up with the ascending sap. 
