130 GARDENING AS A SCIENCE. 
ps. ac.) a seedling of 1831, now a powerful tree. Being ignorant of precise dates, 
we can only state that, at one time or other, the branch of the Portugal laurel, by 
the action, doubtless, of the wind, had sawed a groove into the trunk of the acacia, 
at the same time abrading its own bark, and becoming flattened against the 
alburnum of the stem. The pseud-acacia is, during its youth, a tree of remarkably 
rapid growth, and in the instance now alluded to, it has completely checked the 
farther movement of the laurel, fixed the branch, and is covering it entirely with 
the substance of its own bark. The branch is almost inclosed, and on a level with 
the great trunk ; which latter, if it progress with corresponding energy, will com- 
pletely cover it with the organized matter of acacia, in two years from the present 
period. Now, from these plain facts, we infer that a person observing a branch of 
one tree, say an evergreen, growing out of the substance of a second of very opposite 
habits, might readily presume that the union had been effected by the operation of 
grafting. Our own specimen demands great observation, and some experiments, 
which may hereafter, if they lead to any worthy results, be communicated ; at 
present we leave the bare fact, as described, to the judgment of the reflecting 
reader. 
The Science of Gardening, i. e. the Theory of Horticulture^ does not require 
any minute definition of the mechanical detail of grafting ; that, therefore, is left 
to the practical gardener : what we have to explain, so far as the discoveries of 
Vegetable Physiology enable us to do so, is the cause of those remarkable phenomena 
which attend every successful insertion of a graft or scion, whether that be effected 
by the ordinary process, by inarching, or by crown-grafting. The only distinction 
we shall make will consist in referring the last-named process to the operation of 
" budding," because they both in common require a similar condition of the stock, 
to ensure the successful application of the graft or bud. It is the received opinion 
that the natural qualities of a grafted tree, either as respects stock or scion, remain 
unchanged, each retaining its own individual character uninfluenced by the other. 
If this be strictly the case, of what utility is the practice ? We will for the present 
dismiss minutiae, and at once admit the general correctness of the opinion , for a 
genuine Ribston pippin, grafted either upon a crab, a Siberian, or pippin-stock, 
retains all its individual properties ; while at the same time, the stock, be it what 
it may, is unaffected by the graft. The same may be asserted of the pear upon 
the quince. Let us then approach the phenomena of a grafted tree a little more 
closely, and no longer view them with the negligent regard of custom. Suppose a 
crab-stock, planted in autumn ; it stands during two years in a nursery, its head 
untouched by the knife ; it recovers completely from the torpor occasioned by 
transplantation, grows vigorously, and at the latter end of the third March is three 
quarters of an inch thick at a foot above the ground. A selected scion of the last 
year's wood, which has been cut off a fortnight before, is ready — it is matched and 
adapted to the stock a few inches above the soil. Both members are previously 
cut over, prepared alike, and are fitted into each other by means of a small tongue, 
