260 CONTRIBUTIONS TO 
of producing a leaf; but the direct consequence is by no means 
so generally acknowledged, that for that very reason the woody 
stem cannot come under the idea of plant. Much confusion 
has arisen in our physiology from the error of regarding the 
tree as a single plant, the ideal definition of root, stem, bud, 
&c. have become very vague, and bitter controversies have 
been carried on with respect to the functions of these parts, 
which could have no result, because the one party spoke of 
this, the other of that, this one of the stalk, the other of the 
stem, this of root-fibrils, that of ligneous root-substance. 
The so-called lignified root is, however, just as little a root, 
as the lignified stem is still a stalk, but both together form an 
inseparable, and, moreover, altogether purely accidental organ 
for the plant, which has secreted the annual individual upon its 
surface, in order to bring into connexion, by means of a single 
organized membrane, the whole sum of the newly formed 
young individuals. The tree corresponds precisely to the 
polypidom, and it appears to me to be as unsound to set out 
from it as the type in plants, as it would be for the zoologist 
to take a Gorgonia as the ideal of animal individuality. This 
analogy, however, is in no way weakened by the circumstance, 
that we meet with this woody stem most frequently in precisely 
the highest developed plants ; but, on the contrary, it is natural 
that, if the animal kingdom in a certain measure receive the 
vegetative part of its character from the vegetable kingdom, 
this should connect itself by the lowest stage of animals to the 
highest plants, whilst even this vegetative half of the vital phe- 
nomena in the higher animals is in like manner purified and 
ennobled by its individuality constantly gaining in independence. 
With this explanation of the woody stem (the root included), 
it will henceforward appear by no means remarkable that this 
organ (as if it were a mere organized soil) can generate upon 
every part of its surface young vegetable individuals; that is, 
buds, so soon as it is in a condition to convey nutritive material 
to those buds from any part, whether it correspond apparently 
to the former root or to the stem; while this refined idea of 
the plant conducts to the law, that in the regular course of 
vegetation, neither root nor internode, but only the axilla of 
the leaf, is capable of generating a bud, i. e., a new axis with 
lateral organs. 
