112 
RUDIMENTS OF THE NATURAL SYSTEM OF BOTANY. 
pretensions to the unravelment of the secrets of nature. We seek not to enter her 
inner shrine, or to startle her admirers with profound disclosures. Satisfied to be 
the humble attendants of a noble train of philosophers, we desire only to collect 
their most salient observations ; to draw together, as to a focus, the more brilliant 
of their discoveries ; and, by the concentration of their common light, to diffuse 
a few rays of solid information amongst those who desiderate such knowledge. 
No alarm need be felt by the least learned in the prospect of being carried 
through a host of refined researches. We contemplate the entire avoidance of any- 
thing assimilating to microscopical scrutiny, and purpose confining our simple 
specifications to the external and distinctly perceptible organs of vegetable bodies. 
To enter upon this field in an orderly manner, and survey each portion according 
to the arrangement in which it naturally develops itself, we shall suppose the seed 
of a flowering plant deposited in the soil, and examine the various stages in its 
transformation or advancement till it gives birth to another seed. Roots and stems 
are perhaps protruded nearly at the same time, but as it will best suit our purpose 
to give priority to the former, the assumption, however questionable, may be 
allowed. 
Roots are distinguished from stems by their invariable tendency to increase 
downwards, and seclude themselves from light, and by their having a greater or 
less portion of the surface of their extremities in a state of immaturity, this being 
capable of imbibing fluids. The anomalous instances in which roots are seen 
resembling branches, and producing buds, shoots, and leaves ; or those more 
inscrutable cases wherein they appear purely aerial, and never seek to bury them- 
selves in the earth ; are no disproof of the position above laid down. Even the 
roots of. epiphytal OrchidaceEe, or air plants, subsist only in a shaded position, and 
generally incline to a darkened recess, while their direction is always towards the 
earth's centre, and they have spongy absorbent points, thence called spongioles, 
which are not permanent organs, but simply the incomplete and rudimentary state 
of the newly-formed tissue, by which the greater part of their nutriment is received. 
The feature of most importance in the distinction of roots and stems is, that if their 
proper position be inverted while they are growing, stems will immediately curve 
upwards to the light, and roots, as soon as they reach the surface of the earth, will 
return again in a downward course. The bulb, the corm, and the rhizoma, which 
are often considered roots, are properly modifications of the stems. The only other 
form employed in determining natural orders, is the fasciculated root, in which the 
fibres are unusually large and fleshy, and diverge regularly from the stem in a 
rather slanting direction, as in the Dahlia. 
It has been shown how the internal characters of stems mark the two first 
divisions of the natural system ; and we have here to deal with their external 
variations. They are either arboreous, shrubby, subshrubby, or herbaceous. The 
term arboreous is applied to trees which commonly bear only one stem, issuing 
directly from the roots, and rising to a considerable but indefinite height. Casual 
circumstances sometimes occasion the production of more than one stem to each 
