16 
GENERAL REVIEW 
The greater number of living beings possess numerous organs, and a complicated 
structure. When the functions are various, the structure becomes intricate; but 
tiiere exists a regular gradation — a well-marked hierarchy of functions, os well as of 
organs. All living bodies absorb nutriment, and reproduce their species ; all animals 
move fpontaneously at least some of their parts; many viylbly respire; Man thinks. 
But it is evident th,it the first order of these functions is Nutrition — the other phe- 
nomona always presuppose this one. Let us, then, examine- the subject of Nutrition, 
and we shall assuredly commence at the first link in the vital chain. 
Tlic greater number of Plants have a root fixed in the earth, a stem which shoots 
into the air, and directs itself towards the light. This stem bears leaves, branches, 
and flowers: these flowers, of various degrees of complication, produce fruits or seeds, 
destined to form a succession of beings, similar to those ^vhich have produced them. If 
we desire tu ascertain which of these organs is essential to the existence of the plant, and, 
with this view, we successively abstract these several parts; if we cut off the fruits and 
seeds, the remainder of the plant rests uninjured. Tlie stalk may lose its leaves without 
perishing; it may he cut, and the roots will continue to live and absorb in their or- 
dinary manner — nay, the root will often even reproduce parts similar to those of 
which it has been deprived. The root is, therefore, the most important part of the 
Plant, and by it principally the whole vegetable is noimisheiL 
Something similar to this may be observed in Animals. We see an animal of a very 
complicated structure. A bony skeleton, nerves, organs nf sensation, a brain, muscles 
for motion, a heart for circulating the blood, lungs for absorbing air, a stomach in which 
the nutriment is deposited and prepared, glands for secreting the humours, arrange- 
ments for continuing the species, a general covering for protecting the whole, and 
limbs for changing its situation; — all these organs, and many more, compose its sub- 
stance. In beings of this degree of complication, it. is impossible to assign to each 
organ its proper degree of importance, because wc cannot abstract any without injur- 
ing them all ; and many cannot even be touched without subverting the entire fabric. 
But tins separation, which we should in vain attempt to perform, Nacuro has herself 
realized in the long chain of animated existence. In descend/mg from the viviparous 
Quadrupeds to the Birds, from the Birds to the Reptiles and Fishes, and passing from 
the Birds and Fishes, by the Mollusca and Insects, to the Worms and Polypi, we sec these 
living machines become more simple, until at length we find, in the lowest orders, 
nothing but that first principle indisp-msable to all animab. The whole body of the 
Polypus forms, in fact, nothing but one entire stomach, without any other perceptible 
organ ; and this alone is essential t^j the existence of a being so extremely simple. 
We may thus conclude, that as the root is the first and essential element of the 
plant, so the stomach is the foundation of animal organization. Nature confirms this 
principle throughout all her works. She has created' vegetables which .ire composed 
entirely of oue vast root, and has formed animals of a simple gelatinous mass, con- 
taining only one enormous stomach. AU the functions, are, how'cver, of an extreme 
simplicity in bodies so homogeneous. In order that a vegetable may exist, composed 
entirely of a root, it is necessary that the substances proper to bo absorbed should 
surround this root; it must be attached to a soil, composed of mould, and saturated 
with moisture, or to another plant; and these conditions are sufficient for its individual 
existence. As it produces no flowers, the species can only bo continued by off-sets, 
buds, artificial or natural divisions of the rout ; and it is chiefly in this way that such 
bodies are propagated. But that an animal — Polypus or Worm — composed of ono 
entire stomach, may exist, different arrangements are requisite. The stomach is placed 
internally; therefore, it is erideiit that the food must be carried into it. The animal 
must be able to move towards the food, ami to draw it, by certain partial movements, 
within the cavity. In order to seek its food, it must feel and perceive; while a cer- 
tain degree of instinct must exist, that it may adopt these movements in proportion to 
its wants. Thus, from one fundamental arrangement, there arises a being, perfect 
though simple, but which, though simplest rrf its kind, already appears complicated. 
We have styled the Polypus a simple being, because it is composed of one entire 
stomach. Although it moves, and must feel, we can perceive no muscles, brain, or 
nerves ; it possesses powers, while the instruments remain concealed. Yet the Poly- 
pus must be considered as a perfect being, because to it is assigned all the conditions 
necessary for it.s continued existence: it is in this respect as perfect as a Bird, or as 
one of the Mammalia. It is true that the animal possesses neither a heart nor lungs, 
no vessels or glands; but it has no occasion for them. When the body is one entire 
stomach, and when the animal is perfectly simple and homogeneous throughout, it is 
evident that these structures would be superfluous. Organs are only necessary when 
circulation and respiration arc confined to particular parts. Every portion of the ani- 
mal can draw from the alimentary canal that part of the nutriment necessary for its 
sustenance : it can breathe and assimilate these particles into its proper substance. But 
when the animal is not possessed of this perfect homogeneiiy throughout, it then be- 
comes necessary that it should have a proper stomach to rcctdve the nutriment, a heart 
to distribute it along with the blood into all the organs, and gills or lungs to purify 
this nutriment by exposure to the air. Unity of action is a first principle in life; and, 
in the higher orders of animals, it is the heart and the luiig^ which produce this unity 
in respect to nutrition, in the same manner as the brain realizes the unity of sensation. 
Organization may exist. without life, as living bodies are subject to death; but who- 
ever says Uftif also says Orgunizatlon. Buffon was thercl'ure guilty of a pleonasm, 
when he deiined animals to be — Sodiesy l}i\u<; and orguniz, /L 
This organization of living bodies is regulated by certain fixed rules, which have re- 
ceived the name of Ir.w 5 from their constancy and univcrsali'y. We have juit spoken 
of the perfection and unity observable in all living bodies. The latter, however, is 
not absolute. Animals possessing a complicated Btructure arc in truth individuah; 
but with plants and with the lower animals, individuals cannot be strictly said to exist, 
at least in the sense in which the terra is understood in regard to Man and the higher 
•animals. It is true th.at, as long as the several organs.remaiu untouched, they enjoy 
ono common liib, and form one perfect and consistent being; bat it is not impossible 
to abstract and prune a'way some parts, without interrupting the life of the being thus 
mutilated. We know well that a plant can be deprivetl of its flowers, leaves, and 
branches: there may remain nothing but a divided root, with a mutilated stem; and 
even this vestige of a living being will not cease to enjoy life. Nay, frequently many 
OF LIVING BEINGS. 
of the detached parts will themselves become new beings, when placed under circum- 
stances favorable to their development, A branch and a leaf are sometimes adequate 
to form a vegetable simikir, in all its parts, to the being whence they were derived. 
Upon this fact rest the whole theory and practice of slips and layers. Tho same thing 
is found with certain animals. A naked Polypus, when cut into several pieces, forms 
80 many new and perfect Polypi, which continue to live in exactly the same manner 
as their original stock. Many of the rays of an Asterias, or Sea-star, may be detached 
without destroying the animal. The head.s of slugs may be cut off, and the animats 
survive, even -witlioat any apparent diminution of their vigour. But what seems still 
more astonishing, some of tho vertebrated animals themselves may bo similarly muti- 
lated without being instantly deprived of life. Tortoises and Salamanders, which have 
been decapitated, will still maintain their existence for a considerable time. The Em- 
peror Commodus used to amuse himself with knocking off the heads of Ostriches 
while running round the Circus at Romo; and we are told by the historians of the 
times that they still continued their course. This singular power is even perceptible 
in tho newly-born animals of the class Mammalia, which preserve their existence for 
a very short period, even when similarly injured. Still, however, these arc but 
exceptions to a general law prevailing throughout the Mammalia, the Birds, and even 
among animals less complex and less elevated in the scale of creation. With these we 
in general find, that the extirpation of any important organ w incompatible with life. 
Sudden death speedily follows such an operation. Tlicy are only capable of support- 
ing tho amputation of a limb or appendage; they can only endure a superficial wound, 
or injury. There exists, among all the Vertebrated Animals, a perfect dependence 
among their primary organs. If ono of those be taken away, the remainder of the 
body ceases to live. If one of them be sick or wounded, the injury affects the other 
parts. Tlierc are five hnportint organs, the integrity of which is absolutely essential 
to the continued existence of an animal possessing them; those are the heart, tho 
brain, the organs of respiration, the spinal marrow, and the stomach. When these 
are once associated in a living animal, their co-existence is indispensable ; and any 
serious ^vision or decapitation of a body, provided with these five organs, is speedily 
mortal. 
The parts of a plant are less united and more independent of each other; while 
the destruction of a part docs not lead to the annihilation of the whole, because plants 
arc ne-arly homogeneous. Tlie portions remaining are provided with the same organs 
as the entire being. Precisely tho same cause enables those lower animals to exist, 
which arc formed but of one simple stomach. They possess no special and circum- 
scribed orgaiLs; each of their divided segments partakes of an equal degree of com- 
plexity with the whole. But it is evident that a different result ought to be obsorveil 
among the higher animals, where the functions necessary to tlieir existence are iso- 
lated in special and circumsoribod organs. With them the existence of the indivultud 
rests upon the exact mutual relation of the varied pieces composing the entire body. 
In fact, it is a general rule, which prevails throughout the entire Animal Kin^^dom, 
that the organs essential to life arc concentrated and intimately united in an animal, 
according to its elevation m the scale of creation, or, in other words, according as 
its structure is more or less complex. The variciy and intricacy of the wheel-work 
requires a greater concentration of tho moving power. 
The syranietrlcal forms observable in all Living Beings arc surprising. In re>'^ard to 
the roots of plants, and the branches of large trees, \rc observe that a great irregularity 
generally prevails. But this is owing rather to inequalities of the soil, and to varieties 
in the intensity of light, than to any natural disposition to irregularity in the plants 
themselves. The soil is not composed of uniform materials, and the roots alwavs 
direct their fibres toward those ports w'hich are most easily moved and yield 
the most abundant nutriment. Tho loaves and buds, again, arc delicately sensible to 
nice degrees of light. Wo accordingly observe that the Conifera?, such as tho Pino 
and Fir, being resinous, and cver-green trees, upon which these powers have least 
influence, present the most regular and symmetrical forms. 
The regular arrangement among plants ia no where found in greater perfection 
than among the Labiata*. Wc do not here allude to their flowers, which are not so 
very remarkable in this respect, but to their square stems, their opposite leaves, their 
branches, and their peduncles. In most of tbetus plants, each loaf, taken separately, is 
arranged with regularity. But none even of tliosc can compare with the beautiful 
symmetry observable in llie leaves of the Sensitive Plant, the Acacias, and tlie Firs. 
In by far the greater number of plants, we find the utmost exactness in the distances 
between tho several divisions of the calyx and corolla,— the flowcr-cup, and tlic flower 
itself; in the dimensions of each stamen, of uadi pistil; in every compartment of tho 
ovarium, and of the fruit. With the e.xception of certain flowers analogous to thoso 
of the Acacia.!, of the Labiatai, of the Orchidea*, and some others, tho irregularities 
which many occasionally [tre.^ent are due lo the abortion of certain ports, to their ad- 
herence, or to their transmutation into other forms. 
Ascending to the Animal Kingdom, and arriving at the Polypi, thoso lowest of ani' 
mated beings, wc already find the same symmetrical arrangements. Their cilia, their 
tentacula, or little arms, these appendages of more animated sacs, are dis])osed with 
regularity, around that single orifice, which we dignify by the name of mouth. B 
only in those calcareous and arborescent masses which they form and inhabit, and 
which compose by their aggregation, rocks, islands, and rudimentary continents, that 
we fail to observe tins regular arrangement. We may rccogiii.se the same order if* 
the starry rays of the Euryalia, and in the spinous compartments of the Echini, or Sea- 
urchins. In rcRpi'Ct to Insects, tho sjTmnolryis exquisite. M'e find the same quality 
in many Mollusca, but most particularly in their shells, and in the crustaceous 
lopes of Crabs and Lobsters. 
It is, however, in the higher or Vertebrated Animals that symmetry is brought to 
its greatest degree. Their bones, their nerves, tlieir organs of sense, their brara» 
their muscles, their glands, their gills or lungs, are all arranged in lateral pairs^ 
when their number is even ; or they are placed in the exact central axis of tho body» 
when their number is odd. Wo must admit, however, that it is externally wo can 
best trace this correspondence, for the internal organs are not thus arranged. 
this respect the contrast is altogether surprising: in vain we seek for symmetry ^ 
the disposition of the intestines, the liver, or the heart. 
