9 
GARDENING AS A SCIENCE. 
ART. I. VEGETABLE PHYSIOLOGY. 
The utmost extent to which our investigations enable us to attain is very 
remote from knowledge. Can it then be deemed surprising that very few profes- 
sional gardeners are acquainted with the structure of the plants they cultivate ? 
When the time of any person is almost entirely occupied in works of manual 
labour, how is it possible that he shall be able to bend his mind to severe investi- 
gation of a dark and mysterious subject ? And such is Vegetable Physiology. 
The term is derived from two Greek words, ( phusis , Nature, and legein , to speak 
or discourse of.) Vegetable Physiology implies, therefore, an investigation of the 
natural structure of plants, and it also involves the anatomy or dissection of every 
part and portion of their organization from the seed to the most minute develop- 
ments, external and internal ; and thus, strictly speaking, it includes Botany, 
a word which has been misapplied when restricted to the floral organs of a plant. 
But physiology is still more comprehensive in its pursuits, since it embraces the 
analysis of all the vegetable products ; therefore it appeals to chemistry in the most 
refined and complicated processes of analysis. 
With these considerations before us, and knowing that bold assertions have been 
resorted to on subjects whereon the most humble suggestions only should have been 
offered, we shall do little more than approach the science of physiology, by pointing 
out a few of the most prominent objects of research, adducing occasionally the 
theories of the day, with such remarks as shall appear applicable, in order to 
induce the inquiring and sagacious reader to investigate for himself, and to shun 
that blind credulity which is the greatest obstacle to the attainment of true 
knowledge. 
With this caution, however, we would earnestly advise the student to avail 
himself of every opportunity to attend the lectures upon physiological botany ; for 
though it is wrong to take anything for granted, experience and observation 
produce habits of research. 
In the study of vegetable structure it would appear natural to commence with 
the seeds , or rudiments of plants ; but their organization is so minute and complicated, 
that it might much perplex a beginner. We, therefore, shall for the present confine 
our attention to the external structure of plants ; to those parts which meet the 
eye; referring for our authority to the simple arrangement of that sound physio- 
logist, the late Sir James E. Smith, whose Introduction toBotany we recommend to 
the uninitiated reader. 
1. The Root, radix , is the organ of nourishment, that by which a plant is attached 
to the soil, and absorbs the crude sap. It, in general, appears to be the first deve- 
lopment of vegetable vitality, since the radicle is protruded from a seed into the 
ground, before the stem ascends. A beautiful example of this is furnished by a 
VOL. xi. — no. cxxi. c 
