STEMS OF SHRUBS AND TREES. 
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he convinced of the truth of the above description of the manner of its 
annual growth. 
There is, in fact, no difference of opinion respecting the manner of 
the growth; but there are many conflicting opinions as to the origin of 
the new alburnum. While one insists that it is dilatation of the former 
year’s alburnum, another as confidently asserts that it springs from the 
liber. A few declare that it is formed by a tissue of fibres which 
descend from every bud on the branched head; while all these notions 
are considered untenable by another and very influential class of physi¬ 
ologists, who maintain that the new concentric layer of alburnum, as 
well as all the other parts of the tree, are formed of the elaborated or 
proper juice. To this class the ingenious as well as the ingenuous 
Mr. Hoare seems to belong; and however perfectly natural it was for 
that gentleman to apply to one of the very first authorities fcr the 
tenets of his physiological creed, we are far better pleased with the 
relation of what he himself has observed as the immediate cause of 
well-ripened wood being covered with plump and fruitful buds, viz. 
solar light and heat, and full air, than attributing the same effects to 
inspissated sap absorbed in its passage down to the roots. 
But another difficulty occurs : if we can believe and declare that the 
elaborated sap is organisable,” and. that timber, flowers, and fruit 
can be formed of it, we are in the same breath affirming that an organ¬ 
ised body can be formed out of a pure homogeneous jluid —a pheno¬ 
menon which we verily believe has never yet been manifested among 
the most wonderful mutations of nature. 
We see the sap of plants in all the forms of pure water, mucus, gum, 
and resin; the latter so concreted and hard as to resist the action of 
edge-tools: but never in any state, whether within or out of the tree, 
is ever any sign of organisation apparent; nor are there any of what 
may be called the materials of organisation present, namely, detached 
fibres, cells, or vesicles floating or otherwise contained in the mass, 
which, by the general law of attraction, might by possibility be brought 
into orderly contact, and compose a living being. 
No; to have a rational idea of the origin of either wood, or flowers, 
or of fruit, we humbly conceive that we must descend to the common 
origin or rudiment of all vegetation, and all its parts. And what do we 
learn by such investigation? We see a pre-existing embryo, whence 
arises all subsequent expansion and development. From a seed a 
perfect plant springs up, which, when it has acquired a certain bulk, 
exhibits sue essively all the parts of which it is composed. These 
parts are at first so minute, that they are invisible to the naked eye. 
