ON THE ELIGIBILITY OF DECORTICATING TREES. 413 
bestowed to find a remedy. It should always be kept in mind, 
that our fruit-trees generally are only mules ; and imperfect formation, 
in such cases, is no uncommon thing; and as they may be originated » 
by art, by the same interference they may require to be sustained. 
The practice of cross impregnation is now so well and so generally 
understood as an auxiliary expedient for the purpose of obtaining new 
sorts of flowers and improved kinds of fruit, that it is unnecessary to 
advert to it here; but it should always be considered that, although 
much is already known respecting the powers and susceptibilities of 
plants upon and among each other, we do not yet know all, and there¬ 
fore should be ever looking forward to increase our knowledge, and 
improve our practice in every possible way. 
We have availed ourselves of Mr. Bristol’s hint respecting the 
Lisbon grape, to compare it with other incidents of the kind, and to 
enlarge on the subject, with the sole view of calling attention to the 
matter, believing, as we do, that the most distant hint is very often 
sufficient to an active mind, by directing it to objects and incidents 
which otherwise might be entirely overlooked or neglected.— Ed. 
ON THE ELIGIBILITY OF DECORTICATING TREES, AS A MEANS OF 
RECOVERING THEIR HEALTH AND INCREASING FRUITFULNESS. 
Disbarring old and stunted fruit-trees, for the purpose of inducing 
fresh vigour into the system, is an old custom, and, what is rather 
remarkable, has been much more practised by amateur orchardists than 
by professional gardeners. By the latter, the operation of disbarking 
was deemed an unnecessary counteraction of the law of nature, and a 
kind of cruelty and violence which no organised being could bear with¬ 
out serious injury. The bark, it was urged, is the natural clothing of 
the tree, and trees must suffer if rashly and suddenly divested of it. 
This is certainly plausible reasoning; but when we look to the struc¬ 
ture of a stem, and consider the manner of its accretion and decay, we 
may probably come to another and very different conclusion. 
A stem or trunk of a tree is composed of three very distinct mem¬ 
bers, namely, pith, wood, and bark : these are present from the moment 
the infant plurnula bursts from the seed. At the end of the first year, 
the pith occupies the greater portion of the diametric bulk, surrounded 
by a thin layer or cylinder of wood, and this, by the cuticle, forming 
the first layer of bark. At the end of the second year’s growth, the 
same part of the stem consists of the pith, as before ; two layers or 
circles of wood—the last being formed on the outside of the first layer. 
