84 
REVIEW. 
being resolved into branches. Some of the lower situated are pro¬ 
longed into spurs, and become flower buds, as at f, g, Fig. 5 ; many 
remain dormant, and are never developed, unless the stem be cut over 
immediately above their station. 
From these circumstances it appears, in respect of secondary or 
tertiary buds springing from the vital envelope, that that member is 
possessed of these latent principles, which are put forth when sur¬ 
rounding circumstances favour their developement. It was this fact 
which induced an eminent French botanist to imagine, that vital 
gems floated in the sap; for on no other principle could he account 
for their inexplicable appearance. There are many trees having a 
fine smooth trunk, from which not a spray would be put forth while 
its branched head remained alive: but on being decapitated thou¬ 
sands of shoots would issue from the bole, even if its pith, and almost 
all its body of timber had gone to decay; a strong proof that the 
envelope contains the rudiments or principles capable of being re¬ 
solved into buds as well as of radical fibres. 
It has been supposed by some physiologists, that the medullary 
rays are the tracts of buds, and that all buds originate on, or proceed 
from the pith, but we have no certain evidence of the truth of these 
ideas; on the contrary we find, that buds of many kinds of trees is¬ 
sue from roots where pith has never existed ; and medullary rays, or 
partitions rather, are abundant where no buds are ever, or can possi¬ 
bly be produced, viz. on the internodes of jointed stems ; example, 
the grape vine. And it may be further observed, that in the plant 
just named, the greatest number of shoots, in fact every shoot, is 
ejected from the articulations where the pith is visibly interrupted. 
Of what are called medullary rays, we may observe further, that 
though known by this name, they do not all take their rise from the 
pith; as the stem increases in diameter, intermediate partitions 
come into existence at different distances from the centre, and ap¬ 
pear to originate in the bark rather than the pith. 
This view of the constitution of a tree shows us that it is not, as 
usually considered, an individual being. It has, indeed, a congeries 
of roots, a pith, a principal stem, and a general covering of bark, in 
common : serving the purposes of sustentation, support, and protec¬ 
tion to the whole: but it has not only one—it is composed of many 
principles of life dispersed over its whole surface. A tree is a vege¬ 
table polypus : capable of unlimited division and subdivision of its 
parts without injury to, and without any notable diminution of the 
original. Not only is every seed, but every bud a perfect being, 
endowed with a living reproductive principle in itself; and whilst a 
