Part 5

Notwithstanding the patronage of Buffon, and others having the greatest influence with the government, it was long before Lamarck succeeded in obtaining any permanent and lucrative appointment. His chief dependence was on the casual and precarious engagements which he formed with booksellers, according to whose direction he was obliged to labour; a painful restraint to a man of genius, impatient to develope his own conceptions in whatever way he judged best fitted to render them effective. He was at length nominated by M. de la Billardiere, a relation of his own, to a place which seems to have been created expressly for him, by which the duty was assigned him of keeping the herbaria in the king’s cabinet. Although the emolument arising from this office was inconsiderable, and the tenure of it uncertain and invidious, for the National Assembly were called upon to suppress it as unnecessary, he continued to hold it for several years, till a change occurred which opened new prospects and entailed new duties. This happened in 1793, when the establishment known by the name of the king’s garden and cabinet were remodelled and distinguished by the title of Museum of Natural History. The professors of the suppressed institution were appointed to superintend such departments taught in the new, as most nearly corresponded to their previous occupations; and as Lamarck was the last appointed, he was obliged to take charge of that branch unappropriated by the others, which happened to be the two extensive classes of the animal kingdom, named Insecta and Vermes by Linnæus.

A new direction was thus given to his studies, for zoology as a science had hitherto occupied but little of his regard. Indeed, the only knowledge of this subject which he possessed, directly available in his new station, seems to have been limited to Testaceous Mollusca, which attracted his attention at a pretty early period. But the occasion was just such a one as was best calculated to excite the natural ardour and energy of his character. He entered upon this new field of inquiry with the utmost eagerness, and cultivated it with so much skill and facility, that he was soon in a condition to instruct others, and ultimately to produce works which will form a lasting monument to his fame.

Before engaging in the study of practical zoology, Lamarck had rendered himself conspicuous by the boldness and originality of his speculations regarding a variety of physical phenomena. The general laws of chemistry, the origin of the globe and its inhabitants, the condition of the atmosphere and of living bodies, and most other great questions fitted to attract an active fancy, had by turns been the subjects of his contemplation; and on many of them he had elaborated a theory which he conceived calculated to elucidate the most abstruse phenomena they presented. To these views he attached the highest importance, considering them destined to place almost every branch of knowledge on a new and secure foundation. He therefore took advantage of every opportunity to enforce and illustrate them, and they will be found to pervade most of his published works, even such as afford no obvious plea for their introduction. Although most of them are exploded as fanciful and untenable, these theories display much ingenuity and extensive knowledge, and a pretty full account of them is necessary to show the character of Lamarck’s mind, and the wide range of his studies.

As early as 1780, he had presented his Theory of Chemistry to the Academy of Sciences; but it was not published for several years afterwards, when it appeared under the title of “Researches on the Causes of the most important physical Facts, and particularly on those of Combustion; of the raising of Water in the State of Vapour; of the Heat produced by the Friction of solid Bodies against each other,” &c. &c. A condensed view of the opinions promulgated in that work, and some others on the same subject, is thus given by Cuvier. According to our author, “Matter is not homogeneous; it consists of simple principles, essentially different among themselves. The connexion of these principles in compounds varies in intensity; they mutually conceal each other, more or less, according as each of them is more or less predominant. The principle of no compound is ever in a natural state, but always more or less modified: as, however, it is not agreeable to reason that a substance should have a tendency to depart from its natural condition, it must be concluded, that combinations are not produced by Nature, but that, on the contrary, she tends unceasingly to destroy the combinations which exist, and each principle of a compound body tries to disengage itself according to the degree of its energy. From this tendency, favoured by the presence of water, dissolutions result: affinities have no influence; and all experiments by which it is attempted to be proved that water decomposes, and consists of many kinds of air, are mere illusions, and that it is fire which produces them. The element of fire is subject, like the others, to modification when combined. In its natural state, everywhere diffused and penetrating every substance, it is absolutely imperceptible: only, when it is put in vibration, it becomes the essence of sound; for air is not the vehicle of sound as natural philosophers believe. But fire is fixed in a great number of bodies, where it accumulates, and becomes, in its highest degree of condensation, carbonic fire, the basis of all combustible substances, and the cause of all colours. When less condensed, and more liable to escape, it is acidific fire (feu acidifique), the cause of causticity when in great abundance, and of tastes and smells when less so. At the moment when it disengages itself, and in its transitory state of expansive motion, it is caloric fire. It is in this form that it dilates, warms, liquifies, and volatilizes bodies by surrounding their molecules; that it burns them by destroying their aggregation; and that it calcines or acidifies them by again becoming fixed in them. In the greatest force of its expansion, it possesses the power of emitting light, which is of a white, red, or violet-blue colour, according to the force with which it acts; and it is, therefore, the origin of the prismatic colours, as also of the tints seen in the flame of candles. Light, in its turn, has likewise the power of acting upon fire, and it is thus that the sun continually produces new sources of heat. Besides, all the compound substances observed on the globe are owing to the organic powers of beings endowed with life, of which, consequently it may be said, that they are not conformable to nature, and are even opposed to it, because they unceasingly reproduce what nature continually tends to destroy. Vegetables form direct combinations of the elements; animals produce more complicated compounds by combining those formed by vegetables; but there is in every living body a power which tends to destroy it; all therefore die, each in his appointed season, and all mineral substances, and all organic bodies whatsoever, are nothing but the remains of bodies which once had life, and from which the more volatile principles have been successfully disengaged. The products of the most complex animals are calcareous substances, those of vegetables are argils or earths. Both of these pass into a siliceous state, by freeing themselves more and more from their less fixed principles, and at last are reduced to rock-crystal, which is earth in its greatest purity. Salts, pyrites, metals, differ from other minerals, only because certain circumstances have had the effect of accumulating in them, in different proportions, a greater quantity of carbonic or acidific fire.”

Lamarck’s opinion regarding the origin of living beings, and the manner in which they acquired the various organs and forms which they now possess, are well known. They were first given to the public in 1802, in a work entitled “Researches on the Organization of living Bodies, on the Cause of its Developements, and the Progress of its Composition, and on that Principle, which, by continually tending to destroy it in every Individual necessarily brings on Death.” He conceives that the egg, for example, contains nothing prepared for life before being fecundated, and that the embryo of the chick becomes susceptible of vital motion only by the action of the seminal vapour; but if we admit that there exists in the universe a fluid analogous to this vapour, and capable of acting upon matter placed in favourable circumstances, as in the case of embryos, we will then be able to form an idea of spontaneous generations. The more simple bodies, such as a monad or a polypus, are easily formed; and this being the case, it is easy to conceive how, in the lapse of time, animals of more complex structure should be produced, for it must be admitted as a fundamental law, that the production of a new organ in an animal body results from any new want or desire which it may experience. The first effort of a being just beginning to develope itself, must be to procure the means of subsistence, and hence in time there came to be produced a stomach or alimentary cavity. Other wants, occasioned by circumstances, will lead to other efforts, which in their turn will produce new organs. One of the gasteropode molluscæ, for example, may be conceived to have felt the necessity, as it moved along, of exploring by touch the bodies in its path and to have made efforts to do so with some of the anterior points of its head, which would continually direct to that point masses of the nervous fluid, as well as other liquids: from these reiterated affluences to the point in question, there would follow a gradual expansion of the nerves which terminate there; and as the nutritious and other juices likewise flow to the same point, it must necessarily happen that two or four tentacula would insensibly be produced. This is no doubt what happens in regard to all the gasteropode tribes, whose wants occasion the habit of feeling bodies by touching them with the parts of their head; and when such wants are not felt, the head remains destitute of tentacula, as may be seen in other instances, &c. In like manner it is the desire and the attempt to swim, that had, in time, the effect of extending the skin that unites the toes of many aquatic birds, and thus the web-foot of the gull and duck were at last produced. The necessity of wading in search of food, accompanied with the desire to keep their bodies from coming in contact with the water, has lengthened to these present dimensions, the legs of the grallæ or wading-birds; while the desire of flying has converted the arms of all birds into wings, and their hairs and scales into feathers. Changes of this nature may appear to us contrary to what falls under our observation, which leads us to suppose that the specific forms of animals are constant; but this error is entirely owing to the difficulty we experience in embracing a considerable portion of time within the scope of our observations. It is from this cause that we cannot be ourselves witnesses of these changes, and neither history nor written observations extend to sufficiently remote a date to convince us of our mistake. If we observe that the forms of the parts of animals are always perfect when viewed in relation to their use, as is really the case, it is not to be inferred that it is the form of the parts which has led them to be employed in a certain way, as zoologists assert, but that it is, on the contrary, the need of action which has produced the peculiar parts, and it is the employment of these parts which has developed them, and established a proper relation between them and their functions. To affirm that the form of the parts induced their functions, would be to leave Nature without power, incapable of producing any act, or any change in bodies; and the different parts of animals, as well as the animals themselves, as all created at first, would from that moment present as many forms as are required by the diversity of circumstances in which animals live; and it would be necessary that these circumstances should never vary, and that such should likewise be the case with the parts of each animal. Nothing, however, of this kind takes place, and nothing can be more opposite to the means which observation shows us that Nature employs to call into existence her manifold productions. It must hence appear, that what are called species do not exist in nature; that the constancy of races to which that name has been given, can only be temporary and not absolute, although they would no doubt continue the same as long as the circumstances which effect them undergo no change, and they are not forced to alter their habitudes. It is susceptible of demonstration, that if species had an absolute constancy, there would be no varieties, but naturalists cannot help acknowledging that such exist.

Whatever changes circumstances may have produced in individuals, are all preserved by generation, and transmitted to new individuals emanating from those which have undergone these changes. Unless this were the case, Nature could never have introduced the diversity among animals which we now witness, nor a progression in the composition of their organs and faculties.

Such is Lamarck’s theory of life, and manner of accounting for the innumerable variety of forms in which living nature now appears. If his principles were once admitted, they would not only produce the effects he ascribes to them, but it would be a matter of surprise that natural productions are not infinitely more diversified than they really are, for nothing more is necessary than time and circumstances for any one animal form to be transformed into any other,--for a monad or a polypus to become indifferently a frog, an eagle, an elephant, or a man. But the two suppositions on which they rest, viz. that it is the seminal vapour which organizes the embryo, and that efforts and desires engender organs, are both so entirely arbitrary, and the latter so obviously fallacious, that very few have ever thought it worth while to attempt a formal refutation of them. It is difficult, indeed, to conceive how Lamarck could advance a theory so utterly opposed to observation and probability, and at the same time succeed so effectually in convincing himself of its truth. He must have perceived many of the inadmissible and absurd conclusions to which it led; yet he persists in maintaining it by a kind of sophistry which could impose on none but himself. He admits the value of observation and experience in the discovery of truth; but finding that they bore no testimony to the wonderful transformations he was desirous to prove, he gets rid of their evidence altogether, by alleging that they do not extend over a sufficiently lengthened period to take cognizance of these changes. The argument, therefore, on this point, virtually amounts to this, that observation gives no notice of these operations, but that instead of thence inferring that they do not take place, the proper conclusion is, that they are actually going on, and have been in progress since the creation! How indispensable unlimited time is to give an air of plausibility to Lamarck’s theory, is strikingly evinced by the fact, of which he was perfectly aware, that we have the means of comparing animals that lived upwards of two or three thousand years ago, with the same species as they exist at present, and the conformity between them is found to be complete. Numerous quadrupeds, birds, reptiles, and insects, have been found embalmed in the Egyptian cemeteries, with all the parts in such a state of preservation as to be perfectly recognizable. “It would seem,” says the professors of the museum at Paris, in their report on these valuable remains, “as if the superstition of the ancient Egyptians had been inspired by Nature, in order to transmit to future times a monument of her history. By embalming with so much care the brutes which were the objects of their foolish adoration, that extraordinary and capricious people have left us, in their sacred grottoes, almost complete cabinets of zoology. The climate has conspired with the art of embalming to preserve bodies from corruption, and we can now satisfy ourselves, by our own eyes, what was the condition of many species three thousand years ago. It is difficult to restrain the transports of our imagination, when we behold thus preserved, with their minutest bones, the smallest portions of their skin, and in every respect most perfectly recognizable, many animals, which at Thebes or Memphis, two or three thousand years ago, had their own priests and altars.” In regard to these curious relicts, Lamarck was forced to admit that they were identical with their living descendants in the same country, and accounted for it by saying that this happened because the climate and other physical conditions of the latter had long continued unaltered. But he makes no attempt to account for the fact which is so fatal to his theory, that these remains entirely correspond to individuals of the same species in many different quarters of the globe, where the physical conditions are so dissimilar that they ought to have produced important changes.

It will likewise be observed as an important defect in Lamarck’s argument, that he can cite no positive fact to exemplify the substitution of some entirely new sense, faculty, or organ, in the room of some other suppressed as useless. “All the instances adduced,” says Mr. Lyell, “go only to prove that the dimensions and strength of members, and the perfection of certain attributes may, in a long succession of generations, be lessened and enfeebled by disuse; or, on the contrary, be matured and augmented by active exertion, just as we know that the power of scent is feeble in the greyhound, while its swiftness of pace and its acuteness of sight are remarkable; that the harrier and staghound, on the contrary, are comparatively slow in their movements, but excel in their sense of smelling. We point out to the reader this important chasm in the chain of the evidence, because he might otherwise imagine that we had merely omitted the illustrations for the sake of brevity; but the plain truth is, that there were no examples to be found, and when Lamarck talks of ‘the efforts of internal sentiment,’ ‘the influence of subtile fluids,’ and the ‘acts of organization,’ as causes whereby animals and plants may acquire new organs, he gives us names for things, and with a disregard of the strict rules of induction, resorts to fictions, as ideal as the ‘plastic virtue,’ and other phantoms of the middle ages.

“It is evident, that if some well authenticated facts could have been adduced to establish one complete step in the process of transformation, such as the appearance in individuals descending from a common stock, of a sense or organ entirely new, and a complete disappearance of some other enjoyed by their progenitors, that time alone might then be supposed sufficient to bring about any amount of metamorphosis. The gratuitous assumption, therefore, of a point so vital to the theory of transmutation, was unpardonable on the part of its advocate.”

The transmutability of species is a point which has been maintained by many naturalists besides Lamarck, and the reasons they have adduced in support of their opinions are so various, that the full consideration of them would be inconsistent with our present purpose. It may be assumed as capable of most satisfactory proof, that the mutations which species undergo in accommodating themselves to a change of external circumstances, have a definite limit, and are regulated by constant laws; and that the capability of so varying, forms part of the specific character. Indefinite divergence from the original type is guarded against, in the case of intermixture of distinct species, by the sterility of the mule offspring; circumstances which show that species were designed to retain the individuality of character with which they were endowed at the time of their creation, and that they have a real existence in nature.

The intellectual faculties of animals, Lamarck regards as entirely the result of organization. Even in the case of the most perfect of them, the human species, there is no distinct recognition of a spiritual substance derived from heaven; and all intellectual phenomena whatever, are ascribed to some physical cause. Nature, he conceives, offers nothing cognizable by us but body; the movements, changes, and properties of bodies, form the only field open to our observation, and the only source of real knowledge and useful truths. The place of the soul seems to be usurped by a certain interior sentiment, to which he continually refers, as exercising a most powerful influence over all the faculties, and giving rise to all the passions and affections. Thus the noblest faculties of the mind, “the capability and godlike reason,” by which we are distinguished from other animals,

----and this spirit, This all-pervading, this all-conscious soul, This particle of energy divine, Which travels nature, flies from star to star, And visits gods, and emulates their powers;

are made to emanate from a certain relation of parts and organs,--a particular conformation of material substances, just as a desired result is obtained by arranging in a certain order the parts of a piece of mechanism.

“But who can believe that such a faculty, so divine, so godlike and spiritual, can be the mere result of organization? That any juxta-position of material molecules, of whatsoever nature, from whatever source derived, in whatever order and forms arranged, and wherever placed, could generate thought, and reflection, and reasoning powers, could acquire and store up ideas and notions, as well concerning metaphysical as physical essences, may as safely be pronounced impossible, as that matter and spirit should be homogeneous. Though the intellectual part acts by the brain and nerves, yet the brain and nerves, however ample, however developed, are not the intellect, nor an intellectual substance, but only its instrument, fitted for the passage of the prime messenger of the soul, its nervous fluid or power to every motive organ. It is a substance calculated to convey instantaneously that subtile agent, by which spirit can act upon body, wherever the soul bids it to go and enables it to act. When death separates the intellectual and the spiritual from the material part, the introduction of a fluid, homogeneous with the nervous, or related to it by a galvanic battery, can put the nerves in action, lift the eyelids, move the limbs; but though the action of the intellectual part may thus be imitated, in newly deceased persons, still there are no signs of returning intelligence, there is no life, no voluntary action, not a trace of the spiritual agent that has been summoned from its dwelling. Whence it follows, that though the organization is that by which the intellectual and governing power manifests its presence and habitation, still it is evidently something distinct from and independent of it.”

With opinions having such a decided tendency to materialism, it is not surprising that Lamarck seldom makes allusion to a Deity, and when he does so, he nearly confines himself to the bare acknowledgment of his existence. In his earlier works, there is no mention made of a Supreme Being whatever; and even when his existence is admitted, He is divested of the attributes which belong to him. The glory of forming the works of creation, in which His beneficence and power are so signally manifested, is ascribed to nature, or a certain order of things. This power to which the Deity has delegated his prerogatives, and which he has appointed his vicegerent, Lamarck defines as “An order of things composed of objects independent of matter, which are determined by the observation of bodies, and the whole amount of which constitutes a power, unalterable in its essence, governed in all its acts, and constantly acting upon all the parts of the physical universe.” This blind power, which acts necessarily, has not, indeed, called matter into existence, but it has formed all bodies of which matter is essentially the base; and as it exercises no power except on the latter, which it modifies and changes in every possible manner, producing all its various aggregates and combinations, we may be assured that it is it which has made all bodies such as we now behold them, and that it is Nature which confers on some their properties, and on others the faculties which they exercise. All this power Lamarck distinctly admits has been delegated to Nature by the Deity, and among other errors which he conceives to have attached to the ideas which have been entertained regarding Nature, he refutes the notion that Nature is the Deity himself. “Strange occurrence! that the watch should have been confounded with its maker, the work with its author. Assuredly this idea is illogical and unfit to be maintained. The power which has created Nature, has, without doubt, no limits, cannot be restricted in its will or made subject to others, and is independent of all law. It alone can change Nature and her laws, and even annihilate them; and although we have no positive knowledge of this great object, the idea which we thus form of the Almighty Power, is at least the most suitable for man to entertain of the Divinity, when he can raise his thoughts to the contemplation of him. If Nature were an intelligence, it could exercise volition, and change its laws, or rather there could be no law. Finally, if Nature were God, its will would be independent, its acts unconstrained; but this is not the case; it is, on the contrary, continually subject to constant laws, over which it has no power: it hence follows, that although its means are infinitely diversified and inexhaustible, it acts always in the same manner in the same circumstances, without the power of acting otherwise.”

While thus admitting the existence of the Deity, any direct interference in the affairs of the universe is wholly denied to him. His sovereignty is reduced to a mere nominal supremacy, as he is supposed to take no care or thought for the worlds which he authorized or permitted to be created, and can have no sympathy for the creatures which inhabit them. As with La Place, and so many other philosophers of the French school, every thing is ascribed to secondary causes, which are made to usurp the place and attributes of the Divinity. Lamarck’s deity, therefore, is the exact counterpart of the god of Epicurus, whose being is allowed seemingly more for the purpose of giving consistency to a theory, or a compliance with generally received opinions, than from any urgent conviction of his reality; and we may justly apply to him what was said of the Grecian philosopher; Re tollit, oratione relinquit Deum.

It has been already mentioned, that Lamarck’s attention was early directed to meteorology, and it seems long to have continued to form one of his most favourite studies. So comparatively limited is our positive knowledge of atmospheric phenomena, that a careful investigation of them afforded the prospect of new and important discoveries; while the endless variety of appearances which they present, and the complicated influences which operate in producing them, offered a wide and interesting field for the exercise of that speculative kind of inquiry which Lamarck loved to indulge. With his usual facility in such matters, he was not long in advancing a theory, according to which the atmosphere is regarded as resembling the sea, having a surface, waves, and storms; it ought, likewise, to have a flux and reflux, for the moon ought to exercise the same influence upon it that it does on the ocean. In the temperate and frigid zones, therefore, the wind, which is only the tide of the atmosphere, must depend greatly on the declination of the moon; it ought to blow towards the pole that is nearest to it, and advancing in that direction only, in order to reach every place, traversing dry countries or extensive seas, it ought then to render the sky serene or stormy. If the influence of the moon on the weather is denied, it is only that it may be referred to its phases; but its position in the ecliptic is regarded as affording probabilities much nearer the truth.

So convinced was Lamarck of the accuracy and value of his theory, that he resolved on reducing it to practice, and thus at the same time establish its truth, and attract the attention of the public towards it. For this purpose he drew up a series of almanacks, which he had the perseverance to publish for ten consecutive years, the nature of which will be best understood from the title of that which first appeared. “Annual Meteorology for the Year VIII of the Republic (1800, A. D.), containing an Exposition of the Probabilities acquired by a long Series of Observations on the State of the Weather, and Variations of the Atmosphere, in different Seasons of the Year; an Indication of the Times when it may be expected to be fine Weather, or Rain, Storms and Tempests, Frosts, &c.: finally, an Enumeration, according to Probabilities, of the Times favourable for Fêtes, Journeys, Voyages, Harvest, and other Undertakings, in which it is of Importance not to be interrupted by the Weather; with simple and concise Directions regarding these new Measures.” His predictions, as might have been expected, proved more frequently erroneous than otherwise, but this circumstance was far from inducing him to discontinue his exertions. Every year he had recourse to some new consideration,--such as the phases, the apogee and perigee of the moon, and the relative position of the sun, to account for his previous failure, and afford greater certainty in his future prognostications. After every expedient had been tried without success, he was at last obliged to renounce the labour as fruitless, satisfied that, however important it would be to foresee the state of the weather, it depends on causes far too remote and complex to be made the subject of calculation.

Speculations of an analogous character regarding the formation of the globe and the changes which it has undergone, were laid before the public, in 1802, in a work entitled “Hydrogeology, or Researches on the Influence exerted by Water on the Surface of the terrestrial Globe,” &c. &c. His opinions rest on the assumption that all composite minerals are the remains of living beings. According to him, the seas are continually hollowing out their bed in consequence of being unceasingly agitated by the tides, produced by the action of the moon; in proportion as the bed deepens in the crust of the earth, it necessarily follows that their level lowers, and their surface diminishes; and thus the dry land, formed by the debris of living creatures, is more and more disclosed. As the land emerges from the sea, the water from the clouds forms currents upon its surface, by which it is rent and excavated, and divided into valleys and mountains. With the exception of volcanoes, our steepest and most elevated ridges have formerly belonged to plains, even their substance once made a part of the bodies of animals and plants; and it is in consequence of being so long purified from foreign principles that they are reduced to a siliceous nature. But running waters furrow them in all directions, and carry their materials into the bed of the sea; and the latter, from continual efforts to deepen its bottom, necessarily throws them out on one side or other. Hence there results a general movement and a constant transportation of the ocean, which has perhaps already made several circuits of the globe. This shifting cannot occur without displacing the centre of gravity in the globe; a circumstance which would have the effect of displacing the axis itself, and changing the temperature of the different climates.--In order to silence any doubts that may arise in the minds of his readers from not observing these changes going forward, Lamarck is careful to add, as in the case of the supposed transformation of species, that an unlimited length of time must be allowed for their accomplishment.

But the work on which Lamarck’s fame is principally founded, and which has conferred a most important service on zoology, is his Histoire Naturelle des Animaux sans Vertébres. From the time of its appearance, this work has ever been regarded as one of the highest authority, and has formed the principal regulator of most departments of this extensive race of animals. The work extends to seven octavo volumes, and is entitled “Natural History of invertebrate Animals, presenting the general and particular Characters of these Animals, their Distribution, Classes, Families, Genera, and the principal Species referable thereto.” The first volume is entirely occupied with an introduction, the object of which is to determine the essential characters of an animal, its distinction from vegetables and other natural bodies, and to explain the fundamental principles of zoology. This introduction may be regarded as furnishing a synoptical view of all the author’s peculiar opinions on the origin and developement of living beings, which are illustrated more in detail in separate works. The first five volumes are written entirely by Lamarck, but he was assisted in the part relating to insects by M. Latreille. A portion of the sixth volume and the whole of the seventh, were drawn up by his daughter from his notes and papers, his want of sight preventing him from undertaking that labour himself; and that part of the sixth, which relates to the mytilacés, malliacés, pectinides, and ostracés, is written by M. Valenciennes. The first part was published in 1815, and the other parts appeared at intervals up to 1822, when the whole was completed. Besides a luminous and comprehensive account of the general history of the different groups and genera, the principal species are cited and briefly characterized, with their synonymes, reference to figures, and localities. The enumeration of species sometimes includes all the known kinds, and is particularly copious and instructive in relation to sponges and shell-bearing molluscæ. The genera are established with much discrimination, and judiciously characterized by obvious properties, such as form, proportion, nature of the surface, and structure. The synonymy is unravelled with great care, and the descriptions, though necessarily often very brief, are in general highly satisfactory. These circumstances have rendered this work the most valuable system that has ever appeared of the invertebrate animals; and it has formed the guide to most authors who have since written on the subject.

The phrase invertebrate animals originated with Lamarck, and it expresses, as Cuvier remarks, perhaps the only circumstances in their organization which is common to them all. They were previously known as white-blooded animals, a designation which was soon shown to be improper, by the discovery that an entire class (the annelides) possesses red blood. The system of Linnæus and Bruguière formed the basis of his course when he first began to lecture on the subject; he subsequently adopted a new classification, founded on their anatomy, which had been published in 1795. This he afterwards modified in various ways, as new discoveries were made, and as new relations suggested themselves to him. In his system of invertebrata, forming an octavo volume, published in 1810, he adopted the class of crustacea, and created that of arachnides, a step which he judged necessary, in consequence of some new information that had been communicated to him on the heart and pulmonary sacs of spiders. In a previous work he had admitted the annelides to the rank of a separate class, in consequence of Baron Cuvier’s observations on their circulating organs and the colour of their blood, which resembles that of the vertebrate races. Two other classes were created, in his “Philosophical Zoology,” viz. the infusoria and the centipedes; and in this work also he first deviated from the ordinary practice of commencing the arrangement with the most perfectly organized, the inverse order being more in accordance with his theoretical views, which assumed a gradual progression in the composition of animal organs, proceeding from the most simple to the most complex.

It was in a small volume, entitled “An Extract from the Zoological Course in the Museum of Natural History, on the invertebrate Animals,” &c. published in 1812, that he first presented his general distribution of animals into three grand divisions, apathetic, sentient, and intelligent. This plan he made the foundation of his great work, and the method in which he applied it, as well as his ideas regarding the constitution of the different classes, and their relation to each other, will be understood from the subjoined table.

Invertebrate Animals.

I. APATHETIC ANIMALS.

1. Infusoria. 2. Polypes. 3. Radiarii. 4. Vermes. (Epizoaires.)

II. SENTIENT ANIMALS.

5. Insecta. 6. Arachnides. 7. Crustacea. 8. Annelides. 9. Cirrhipedes. 10. Mollusca.

Vertebrate Animals.