14 PROPAGATION 
In the case, however, of very small trees cr stocks, whicl are 
grafted below the surface of the ground, as is frequently ine 
practice-with the Apple in American nurseries, the stocks are 
grafted in the house in winter, or early spring, put away care 
fully in a damp cellar, and planted out in the spring; but this 
method is only successful when the root is small, and when the 
top of the stock is taken off, and the whole root 1s devoted to 
supplying the graft with nourishment. : 
The theory of grafting is based on the power of union between 
the young tissues, or organizable matter of growing wood. ‘When 
the parts are placed nicely in contact, the ascending sap of the 
stock passes into and sustains life in the scion; the buds of the 
latter, excited by this supply of sap and the warmth of the sea 
son, begin to elaborate and send down woody matter, which, 
‘passing through the newly granulated substance of the parts in 
contact, unites the graft firmly with the stock. “If” says De 
Candolle, “ the descending sap has only an incomplete analogy 
with the wants of the stock, the latter does not.thrive, though 
the organic union may have taken place; and if the analogy be- 
tween the albumen of stock and scion is wanting, the organic 
union does not operate, the scion cannot absorb the sap of the 
stock and the graft fails.” 
Grafting therefore is confined within certain limits. A scion 
from one tree will not, from the want of aflinity, succeed on every 
other tree, but only upon those to which it is allied. ‘We are, in 
short, only successful in budding or grafting where there is a 
close relationship and similarity of structure between the stock 
and the scion. This is the case with varieties of the same species, 
which take most freely, as the different sorts of Apple; next with 
the different species of a genus as the Apple and the Pear, which 
grow, but in which the union is less complete and permanent; 
and lastly with the genera of the same natural family, as the 
Cherry on the Plum—which die after a season or two. The 
ancients boasted of Vines and Apples grafted on Poplars and 
Elms ;: but repeated experiments, by the most skilful cultivators 
of modern times, have clearly proved that although we may, 
once in a thousand trials, succeed in effecting these ill assorted 
unions, yet the graft invariably dies after a few months’ growth.* 
The range in grafting or budding, for fruit trees in ordinary 
® The classical horticulturist will not fail to recall to mind Pliny’s account 
of the tree in the garden of Lucullus, grafted in such a manner as to bear 
Olives, Almonds, Apples, Pears, Plums, Figs, and Grapes. There is little 
doubt, however, that this was some ingenious déception—as to this day the 
Italian gardeners pretend to sell Jasmines, Honeysuckles, &c., growing to- 
gether and grafted on Oranges and Pomegranates. This is ingeniously 
managed, for a short-lived effect, by introducing the stems of these smaller 
plants through a hole bored up the centre of the stock of the trees—their 
roots being in the same soil, and their stems, which after a little growth 
fill up these holes, appearing as if really grafted. : 
