34 
lliis stfite of a tree, the shoots, foliage, and flowers, are all 
diminutive. Tlie fruit rarely sets, and if it does, never arrives 
at full perfection. Besides these defects, such languid trees are 
the favourite prey ol insects, whose depredations, adding to the 
general debility of their victim, sooner or later occasions pre- 
mature di.ssolution. 
67 Decortication of Apple Trees should he had recourse to 
when they are bark -bound as above described. If the tree be 
twenty years old, sixteen of the exterior layers may be shaved off 
with impunity. The vital membrane situated within the bark 
and wood, and whence all accretions arise, is the only vulnera- 
ble member of a tree, and so that this is left entire no bad conse- 
quence can ensue. If, indeed, only one layer be left, it will be 
a suflicient protection to the new layers of bark and wood; and 
which, when relieved from the compression of the exterior lay- 
ers, will immediately assume healthy functions, swell into full 
volume, and yield to the languishing head the long-wanted sup- 
ply of nutrient sap. It should be understood, that it is chiefly 
through the vital membrane and the recently formed layers of 
bark and wood, on each side of it, that all connexion between 
the roots and branches is maintained. The action of the ex- 
tremities is reciprocal, an increased demand of the head is an- 
swered by an increased supply from the root. At the same 
time, the member which forms the connexion, is itself enlarged 
to enable it to perform the office of a conduit. But if this en- 
largement cannot take place by reason of constriction, derange- 
ment of the natural processes follows, and a general stagnation 
is induced. Removing at least half the substance, of the outer 
bark, not only gives liberty to the vital organization, but in a 
most efficient manner frees the ti’ee of the nests and eggs of in- 
sects so injurious to them. The smoothed surface of the stem 
and branches is also, for several years after decortication, less in- 
viting to the parent insects to choose for nestling places for 
their broods. 
6fi The Growth of Vegetables is a phenomenon ever before 
our eyes. We can observe the apparently formless embryo 
swell into a tree of vast bulk. Every member of the system re- 
ceives annual additions, some of which persist for a limited time; 
others quickly perish never to be renewed. But whence is de- 
rived, and how is the accretory matter accumulated ? One 
67, 68, J. Main. 
