16 



GENERAL REVIEW OF LIVING BEINGS. 



The greater number of living beings possess numerous organs, and a complicated 

 structure. When the functions are various, the structure becomes intricate; but 

 there exists a regular gi-adation — a well-marked hierarchy of functions, as well as of 

 organs. All living bodies absorb nutriment, and reproduce their species ; all animals 

 move spontaneously at least some of their parts; many visibly respire; Man thinks. 

 But it is evident that the first order of these functions is Nutrition — the other phe- 

 nomena 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. 



The 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 which have produced them. If 

 we desire to 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. The stalk may lose its leaves without 

 perishing ; it may be 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 nourished. 



Something similar to this may be observed in Animals. "We see an animal of a very 

 complicated structure. A bony skeleton, nerves, organs of 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, aiTange- 

 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 ascign to each 

 organ its proper degree of importance, because we cannot abstract any without injur- 

 ing them all; and many cannot even be touched without subverting the entire fabric. 

 But this separation, which we should in vain attempt to perform, Narure has herself 

 realized in the long chain of animated existence. In descending 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 see these 

 living machines become more simple, until at length we find, in the lowest orders, 

 nothing but that first principle indispensable to all animals. The whole body of the 

 Polypus forms, in fact, nothing but one entire stomach, without any other perceptible 

 organ; and this alone is essential to 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 are composed 

 entirely of one vast root, and has formed animals of a simple gelatinous mass, con- 

 taining only one enormous stomach. All the functions, are, however, 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 subst-ances proper to be 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 be continued by ofF-sets, 

 buds, artificial or natural divisions of the root ; and it is chiefly in this way that such 

 bodies ai'e propagated. But th.at an animal — Polypus or Worm — composed of one 

 entire stomach, may exist, different arrangements are requisite. The stomach is placed 

 internally ; therefore, it is evident that the food must be carried into it. The animal 

 must be able to move towards the food, and to di'aw 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 of 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 its 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 are 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 homogeneity thi'oughout, it then be- 

 comes necessary that it should have a proper stomach to receive the nutriment, a heart 

 to distribute it along with the blood into all the organs, and gills or lungs to pm-ify 

 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 lungs which produce this unity 

 in respect to nutrition, in the same manner as the brain realizes the miity of sensation. 

 Organization may exist without life, as living bodies are subject to death ; but who- 

 ever says Life, also says Organization. Buffon was therefore guilty of a pleonasm, 

 when ho defined animals to be — Bodies, living and organized. 



This organization of living bodies is regulated by certain fixed rules, which have re- 

 ceived the name of liws from their constancy and universahty. We have just spoken 

 of the perfection and unity observable in all living bodies. The latter, however, is 

 net absolute. Animals possessing a complicated structure are in truth individuals; 

 but with plants and with the lower animals, individuals cannot be strictly said to exist, 

 at least m the sense in which the term is understood in regai'd to IMan and the higher 

 animals. It is true that, as long as the several organs remain untouched, they enjoy 

 one common life, and form one perfect and consistent being; but it is not impossible 

 to abstract and prune away some parts, without interrupting the hfe of the being thus 

 mutilated- We know well that a plant can be deprived 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 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. The same thing 

 is found with certain animals. A naked Polypus, when cut into several pieces, forms 

 so 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-stai-, may be detached 

 without destroying the animal. The heads of slugs may be cut off, and the animals 

 survive, even without any apparent diminution of their vigour. But what seems still 

 more astonishing, some of the vertebrated animals themselves may be 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 Rome; and we are told by the historians of the 

 times that they still continued their coiurse. This singular power is even perceptible 

 in the newly-born animals of the class Mammaha, 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 Mammaha, 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 is incompatible with life. 

 Sadden death speedily follows such an operation. They are only capable of support- 

 ing the 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 one of these 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. There are five important organs, the integrity of which is absolutely essential 

 to the continued existence of an animal possessing them; these are the heart, the 

 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 division 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 does not lead to the annihilation of the whole, because plants 

 are nearly homogeneous. The portions remaining are provided with the same organs 

 as the entire being. Precisely the same cause enables those lower animals to exist, 

 which are formed but of one simple stomach. They possess no special and circum- 

 scribed organs; 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 observed 

 among the higher animals, where the functions necessary to their existence arc iso- 

 lated in special and circumscribed organs. With them the existence of the individual 

 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 Kingdom, 

 that the organs essential to life are concentrated and intimately united in an animal, 

 according to its elevation in the scale of creation, or, in other words, accordino- aa 

 its structure is more or less complex. The vai'iety and intricacy of the wheel-work 

 requires a greater concentration of the moving power. 



The symmetrical forms observable in all Living Beings are surprising. In regard to 

 the roots of plants, and the branches of large trees, we 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 parts which are most easily moved and yield 

 the most abundant nutriment. The leaves and buds, again, are delicately sensible to 

 nice degrees of light. We accordingly observe that the Coniferee, such as the Pine 

 and Fir, being resinous, and ever-green trees, upon which these powers have least 

 influence, present the most regular and symmetiucal forms. 



The regular arrangement among plants is no where found in greater perfection 

 than among the Labiate. We 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 these plants, each leaf, taken separately, is 

 arranged with regularity. But none even of those can compare with the beautiful 

 symmetry observable in the leaves of the Sensitive Plant, the Acacias, and the Firs. 

 In by far the greater number of plants, w*e find the utmost exactness in the distances 

 between the several divisions of the calyx and corolla, — the flower-cup, and the flower 

 itself; iu the dimensions of each stamen, of each pistil; in every compartment of the 

 ovarium, and of the fruit. With the exception of certain flowers aiialogous to those 

 of the Acacias, of the Labiatce, of the Orchidece, and some others, the irregularities 

 which many occasionally present are due to the abortion of certain parts, to their ad- 

 herence, or to their transmutation into other forms. 



Ascending to the Animal Kingdom, and aiTivmg at the Polypi, those lowest of ani- 

 mated beings, we already find the same symmetrical arrangements. Their cilia, their 

 tentacula, or httle arms, these appendages of mere animated sacs, are disposed with 

 regularity, around that single orifice, which we dignify by the name of mouth. It is 

 only in those calcareous and arborescent masses which they form and inhabit, and 

 which compose by their aggregation, rocks, islands, and rudimentary continents, that 

 wc fail to observe this regular arrangement. We may recognise the same order in 

 the starry rays of the Euryaha, and in the spinous compartments of the Echini, or Sea- 

 urchins. In respect to Insects, the synnmetry is exquisite. We find the same quality 

 in many IMollusca, but most particularly in their shells, and in the crustaceous enve- 

 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, their organs of sense, their brain, 

 their muscles, their glands, their gills or lungs, are all arranged in lateral pairs, 

 when tlieir number is even ; or they are placed in the exact central axis of the body, 

 when their number is odd. We must admit, however, that it is externally we can 

 best trace this correspondence, for the internal organs are not thus arranf^ed. In 

 this respect the contrast is altogether surprising: in vain we seek for sjTnmetry in 

 the disposition of the intestines, the liver, or the heart. 



