ns 
PHYSIOLOGICAL VIEWS. 
e b a 
Fig. 120, at A, represents a section of the stipe or stem of a palm- 
tree ; at B, is the same magnified ; a, 6, shows a part of the stipe in 
which the woody fibres are most dense and hard ; b, c, shows the 
fibres less numerous, less compact, and less hard ; c, d, includes the 
woody fibres, tender and scattered ; the orifices of tubes which have 
disappeared are seen at c, a. In the part c, d, the cellular tissue oc- 
cupies a greater space than at c, 6, and much more than at b, a, 
where the woody fibre, or vascular texture, predominates. The 
fibres at e, are of new formation ; at^^ they are older, and at g, still 
more ancient ; thus the development of the wood in this plant pro- 
ceeds inversely to that of dicotyledonous plants. 
Endogenous plants continue to increase in height, long after they 
cease to grow in diameter ; the stem is gradually extended upward 
by new terminal shoots, which are formed annually. 
The epidermis is formed of the foot-stalks of leaves, which an 
nually sprout from the rim of a new layer of wood ; the leaves fall 
ingin autumn, their foot-stalks become indurated, and remain upon 
the outer surface of the plant. 
We have now taken a brief view of the most important facts ano 
principles which constitute the science of vegetable anatomy and 
physiology. Although the vegetable structure is much less compli- 
cated than the animal, there are many analogies between them ; and 
many parts of the former have been named, and various phenomena 
explained, by a reference to names and principles common to animal 
anatomy and physiology. You cannot therefore expect, at the first 
glance, to comprehend explanations which presuppose some know- 
ledge of those intricate subjects. By attention to the vegetable struc- 
ture, you will, doubtless, be induced to think more upon the wonderful 
mechanism of your own material frames; upon the analogy, and 
yet infinite difference, between yourselves and the lilies of the field. 
In considering these things, we are led to exclaim, in the language 
of the Psalmist, " Oh Lord, how manifold are thy works, in wisdom 
hast thou made them all !" The human body is nourished by the 
same elements as the grass which perisheth; the flowers have a 
much more refined corporeal substance than you, but how much 
more precious are you in the sight of the Almighty! 
Do you ask, why you are of more value "than the lilies of the 
^eld," or even than "many sparrows?" It is the very principle 
What is Fig. 120 desij?ned to illustrate?— How is the Epidermis formed ? -JlelleC' 
tioiis on the analoisies between the vegetable and animal substances. 
