ORGANIZED BEINGS— ANIMALS AND PLANTS. 
Every organized being produces others resembling it. Without this 
provision, all species would become extinct, since death is the necessary 
consequence of the continued action of life. Certain animals possess the 
power of reproducing some of their parts, after these have been removed. 
This power is termed iiepboduction, and it is found in various degrees 
of perfection, according to the species. 
In general, this power of renovating mutilated parts is found to exist most per- 
foetly in the lower species of organized Ireings. 'I'he head of the snail (^Limax, Linn.') 
may be cut oft', and the whole organ, including its elegant telescopic eyes, will be re- 
produced. The claws, feet, and feelers (or antennee) of crabs and lobsters, as well as 
(he limbs of sjhders, when amputated, arc completely restored by the fresh growth 
of new organs. AVhen accident deprives a shark of its teeth, they are replaced wil.h 
facility. If the ftiw of fishes he cut, they will reunite, and the raya thcrasolves will ho 
reproduced, provided only the small parts at their bases are left. The eyes of lizards, 
though possessed of an intricate apparatus of coats and humours, if removed, will be 
replaced by new eyes equal to the former. Even nun and the higher animals possess 
the same power, only restricted within narrower limits. Injuries to various parts of 
our frame are speedily repaired, and the wounds heal. The effect of injury to a living 
hone is curious. A new bone is produced round the old one; which finally dies, and 
is absorbed or discharged. The new bone, which at first was spongy in its texture, 
and irregularly formed, assumes, in a few years, its natural dimensions, and all ap- 
pearance of chaiigo is completely removed. Thus we see the bountiful provision of 
Nature, and the effect of that principle of reproduction, which restores most of the 
organs of the body to their natural form and action, when deranged by injury or by 
disease. 
Organized beings are developed with greater or less rapidity and perfec- 
tion, according as they arc placed in favorable or unfavorable circum- 
stances. Heat, the quantity or quality of their nutriment, and other 
causes, exercise considerable influence over them ; and this infltience may 
extend over the whole frame, or he confined only to certain organs. 
Hence, it follows, that the resemblance between the progeny and its 
parents can never be perfectly exact. These minor differences among 
organized beings are called varieties. 
The different kinds of dog (^Canis familiaris, Linn.), of horse (Equus cahallus, 
Linn.), of sheep (Oris arics, Desjn.), are all varieties of the same species, and are pro- 
duced by merely accidentul causes, such as domestication, climate, &e. By cultivation, 
the sloe has been transformed into the plum, and the crab-tree into the apple-tree. The 
'■'auliflower and red cabbage, though apparently very different plants, are descended 
from the same parents, — the wild Brassica oleracoa, — a weed growing near the sea. 
Air Herbert relates, in the Horticultural Transactions, that ho succeeded in raising, 
from the natural seed of a highly-manured red cowslip, a primrose, a cowslip, oxlips 
"f the usual and other colours, a black polyanthus, a hose-in-hoso cowslip, and a 
natural primrose, bearing its flower on a polyanthus stalk ; — all these are instances of 
varieties, depending upon soil and situation. 
There is, liowevor, tin real ground for supposing that all the diff'erences 
observable in organized beings are the result of accidental circumstances. 
Every thing hitherto advanced in favour of this opinion is purely conjec- 
tural. Oil the contrary, experience clearly shows, that, in the actual state of 
the globe, species vary only within very narrow limits ; and, as far as past 
researches liave extended, these limits arc found to have been in ancient 
times the same as at present. 
The French naturalists, who visited Egypt vs-ith Bonaparte, found the bodies of tho 
crocodile, tho ibis, the dog, the cat, the bull, and the ape, which had been embalmed 
three thousand years ago by the Egyptians its objects of veneration, to he perfectly 
identical w ith the living species now seen in that country, even to tho minutest bones 
end the smallest portions of their skins. Tho common wheat, the fruits, seeds, and 
“ther parts of twenty dift'eront species of plants, were also discovered, some of them from 
closed vessels in the sepulchres of the kings ; and they resembled in every respect the 
plants now growing in the East. The human mummies, also, exactly corresponded 
"uh the men of the present day. 
Wo arc, therefore, compelled to admit that certain forms have been 
''t'gularly transmitted to us from the first origin of things, without having 
tran.sgressed the limits assigned to them, [except in a slight degree, when 
ihodified by certain accidental circumstances.] All beings, derived from 
’-I'e same original form, are said to constitute a species -, and the varieties 
“fe, as has been stated, the accidental subdivisions of species. 
Generation appears to be the only means of ascertaining the limits by 
which varieties are circumscribed ; and we may therefore define a speciks 
be — a group or assemblage of individuals, descended, one from another, 
'W from common parents, or from others resembling them, as much as 
resemble each other. However rigorous this definition may appear, 
'ts application in practice to particular iudividuids is involved in many 
difficulties, especially when we are unable to make the necessary experi- 
tiients. 
In conclusion, we shall repeat, that all living bodies are endowed with 
functions of absorption [by which they draw in foreign substances] ; 
assimilation [by wliich they convert them into organized matter] ; of 
^^^halation [by whicli they surrender their superfluous materials] ; of de- 
velopment [by which their jiaris increase in size and density] ; and of 
generation [by which they continue the form of their species.] Birth and 
death are universal limits to their existence: the essential character of 
their structure consists in a cellular tissue or network, capable of con- 
tracting; containing in its meshes fluids or gases, ever in motion: and the 
bases of their chemical composition are substances, easily convertible into 
liquids or gases ; or, into proximate principles, having great affinity for each 
other. Fixed forms, transmitted by generation, distinguish their species, 
determine the arrangement of the secondary functions assigned to each, 
and point out the part they arc destined to perform on tile great stage of 
the universe. The.se organized forms can neither produce themselves, nor 
change their characters. Life is never found sepvarated from organization ; 
and, whenever the vital spark bursts into a flame, its progress is attended 
l)y a boaufil'ully-organized body. The impenetrable mystery of the pre- 
existence of germs alike defies observations the most delicate, and medi- 
tations the most profound. 
Wo trace an individual to its parents, .and these again to their parents. After a few 
generations the clue is lost, and in vain we inquire, Whence arose the first animal 
of the species? and what produced the first germs from which have descended the 
innumerable trihos of animals and plants, that we see in constant succession rising 
around us? WTience did the species jian arise? Philosophical inquiry fails to lead 
us through the labyrinth ; and we fed the force of the same principle which inspired 
Adam, when he says, with Milton, 
“ Thou sun, fair light. 
And thou enlightened earth, so fresh and gay, 
Ye hills .md ikies, ye rivers, woods, and plains, 
And ye that live and move, fair creatures, tell, 
T 111! if you saw, how came I thus, how hero, 
Not of myself?" 
SECT, III DIVISION or OIIG.A.NIZED BEINGS INTO .*NI.MALS AND PLANTS. 
Animuh and Planti — IrritahUity — Animals possess Intestinal Canals Circulating 
Sgstem — their Chemical Composition — Respiration. 
Living or organized beings have been subdivided by universal consent, 
from the earliest ages, into animals endowed with sensation and motion, 
and into plants destitute of both, and reduced to the simple powers of 
vegetation. 
Some plants retract their leaves when touched ; and all direct tlieir roots 
towards moisture, and their flowers or leaves towards air and light. Cer- 
tain parts of plants even exliibit vibrations, unassignable to any external 
cause. Yet, these difl'erent movements, when attentively examined, are 
found to possess too little resemblance to tho motions of animals, to au- 
thorize us in considering them as proofs of perception and of volition. 
They seem to proceed from a power, possessed in general by all living substances, 
of contracting and expanding when stimulated, — a power to which tho name of 
irritahiUiy has been assigned- The fibres composing the heart of animals alter- 
nately expand and contract, altogether independent of the will of the animal; and 
thick hair will grow on the skins of some animals, when removed into a cold climate. 
As wc neither ascribe volition nor sensation to the heart or to the hair, so we cannot 
attribute these qualities to the heliotrope, to the sun-flower, or to the sensitive plant. 
The nice distinction of character must be cautiously olisorved, between sensation and 
mere irritability ; like the higher powcr.s of reason and instinct, they arc 
“ For ever separate, yet for ever near.” 
The power of voluntary motion in animals necessarily requires cor- 
responding adaptations, even in tliose organs simply vegetative. Animals 
cannot, like plants, derive nourishment from the earth by roots ; and hence 
they must contain within tliemselves a supply of aliment, and carry the 
reservoir witli tliem. From this circumstance is derived tlie first trait in 
the character of animals. They must possess an intestinal canal, from 
wliich the nutritive fluid may penetrate, by a species of internal roots, 
tlirougli pores and vessels into all parts of the body. The organization 
of this cavity, and of the parts connected with it, ought to vary accord- 
ing to the nature of tiie aliments, and the transformations necessary to 
supply the juices proper to bo absorbed; whilst the atmosphere and the 
earth liave only to present to vegetables tlie juices .already prepared, 
wiien they are immediately absorbed. 
Animal bodies, having tlius to perform more numerous and varied func- 
tions than plants, ought to possess a much more complicated organization ; 
and, in consequence of their several parts having the power of changing 
their position relatively to each otlier, it becomes necessary that tlie motion 
of the fluids should be produced by internal causes, and not be altogether 
dependent on the external influences of heat and of the atmosphere. 
This is the reason tliat animals are endowed with a circulating system, or 
