the days of Aristotle downward; but it has been studied either from mere curiosity, or because, human anatomy being interdicted, the anatomy of animals was the only available source of instruction. Not until the last few years have the lower animals occupied much attention; not until quite recently have they been studied with the philosophic purpose of gathering from them answers to the more difficult problems of Biology. Hunter was ridiculed by his professional brethren; and some of the sons of those laughers are among the most studious of his followers. Men like Swammerdamm, Bonnet, Lyonnet, Reaumur, Trembley, and Spallanzani, devoted patient days to the minute labor of investigating the structure and functions of insects and polypes; but even these great workers were moved by curiosity rather than by biological philosophy. The marvels of organization fascinated them. They saw in these marvels new and surprising proofs of creative wisdom, and were content with such discoveries. Swammerdamm, indeed, declares that the organization of these inferior creatures is more wonderful than that of man *-an exaggeration natural and excusable in one who had given his life to the dissection of what in those days of imperfect classification were called "insects." Ray, Paley, and other natural theologians have also sought for arguments in these marvels. But in none of these writers is there a glimmering of the conception now familar to all students of Biology-namely, that in these simpler forms we must seek the materials for a true elucidation of vital phenomena. The history of this conception would be well worth tracing, but it demands an erudition to which we can make no pretense. The story would open with Aristotle, who, in his History of Animals, displays an astounding knowledge of anatomical details, but a complete absence of philosophic method. That he was better acquainted with the structure of animals than any man before Cuvier, will be evident to the impartial student. Many of the discoveries of modern zoologists are now ascertained to have been clearly known to him; and it is certain, even from his very errors, that the abundant * Bibel der Natur. Leipsig, 1752, (but written nearly a century earlier.) The passage referred to is the opening paragraph. details he has assembled were for the most part directly observed by him. In the first four books* he gathers together facts which, if systematically arranged, would form a treatise of Comparative Anatomy; and in the fifth, sixth, and seventh books he assembles the facts of Generation. But throughout the work we miss any object beyond that of conveying anatomical and zoological details. Naturally enough his successors were inspired with no higher purpose. In the prosecution of human anatomy, animals were often dissected; and many important discoveries have their origin in such dissections-for instance, the lymphatic vessels discovered by Aselli in the dog. But even the growing tendency to seek for illustration in the structure of animals was greatly retarded by the authority of Boerhaave-who, by the way, was the editor, and the very perverse arranger of Swammerdamm's Biblia Natura. His arguments against comparative anatomy were based on his mechanical theory of the animal organism; for no sooner was this organism conceived as a mechanism, than the differences in size, weight, and position of the various organs would necessarily so far affect every question as to render comparative anatomy useless. Vicq d'Azyr and Goethe were the first to perceive the biological value of the comparative method, and since then Lamarck, Cuvier, Geoffroy St. Hilaire, Blumenbach, Meckel, Hunter, Oken not to mention living names-have erected comparative anatomy and philosophic zoology into sciences of daily increasing importance and popularity. It is but a little while since Lamarck laid the basis of philosophic zoologysince Geoffroy St. Hilaire demonstrated the unity of composition in animal forms— since Cuvier undertook to coördinate that vast and heterogeneous mass of details which then formed the Linnean division "Vermes," and since he made his admirable drawings of the cuttle-fish with the very ink furnished him by the animal; yet to compare Lamarck's first sketch and Cuvier's first sketch with the elaborate and systematic presentation of the animal *Carus, in the preface to the third volume of his Comparative Anatomy, translated by Jourdan, says, "Le premier chapitre de son Histoire des Animaux est un vrai traité d'Anatomie comparée." If this is not an oversight of the translator, it is a strange mistake in so careful a writer. "The remaining bodies are called organic, because they consist of different parts, of fibres, called organization. In these bodies there prevessels, cells, &c., the combination of which is vails that mutual dependence betwen all the parts, of which in the inorganic we recognize no trace." series given in Van der Hoeven's work, erudition and terse exposition. Amazingly now lying before us, is like passing from familiar with the literature of his subject, the chemistry of Lavoisier and Black to the author is enabled to further students the chemistry of Liebig and Graham: so by ample information as to the monorapid have been the advances, so great graphs and treatises where fuller detail may the accumulations of the sciences. Does be sought. No one will expect that a it not seem incredible that the law of men- work embracing so vast a multiplicity of tal development being proportional to the details can be free from omissions; necesdevelopment of the brain is no older than sarily, also, it will contain several errors; Sömmering, who died in 1830? How and this because the truth of to-day often could men fail to have made the observa- becomes the error of to-morrow, and betion? one is tempted to ask, until reflec- cause a compiler of treatises such as this tion assures us of the difficulty there is in is often compelled, no matter how extenmaking such observations before a certain sive his knowledge, to speak of animals direction has been given to the thoughts. only superficially known to him, someDoes it not also seem incredible that times not known to him at all. We may men should for so many centuries have as well occupy our remaining space with collected shells, written about shells, prided noting a few of the questionable points themselves on conchological erudition, and which have occurred to us in reading the that not until 1774 did a naturalist-O. F. work, submitting them to the editor's consiMüller-raise an energetic protest against deration when another edition is called for. the absurdity of bestowing so much atten- At p. 3, Van der Hoeven discriminates tion on the house, and neglecting the in-between organic and inorganic bodies, habitant of the house; although, surely, and after characterizing the minerals, Swammerdamm's researches on snails were adds: alone sufficient to fix curiosity in that direction? The internal structure of molluscs has since the days of Poli and Cuvier been a primary object of inquiry among anatomists, and thanks to men like Della Chiaje and Richard Owen, our own generation has worthily continued this impulsion. Having thus indicated the importance and position of the study of comparative anatomy and philosophic zoology, especially of the lower animals, we may now call the reader's attention to the particular work issued from Cambridge, which is intended to facilitate such studies. It has long enjoyed a high reputation on the Continent, and has been very carefully translated by the Cambridge Professor, who has thereby conferred a substantial benefit on the public, a benefit which would have been greater had he exercised a little more editorial privilege, correcting or adding to his original such details as the advancing condition of zoology render necessary. The reader must not be misled by the nature of our introductory remarks, nor expect to find in Van der Hoeven's work any exposition of those philosophical principles to which zoology can be made subservient. It is a Handbook, nothing more, nothing less. It is erudite, trustworthy, compact: a dictionary of families and genera; but by no means a work to teach the beginner, or to assist the philosopher. Its great merits are conscientious Even if we accepted Ehrenberg's views, now almost universally discredited, of the infusoria as "highly organized" animals, we should still point to the indisputable facts of the Amoeba without any differentiated structure at all; of various Protozoa whose structure may be, ideally at least, reduced to a single cell; and of all the unicellular plants, in none of which can fibres, vessels, cells, &c., demarkate the individual from the inorganic world; consequently Van der Hoeven's definition fails where it is most urgently demanded, since no one desires a definition to enable him to recognize the difference between a highly organized animal and a mineral. At page 67 we read: "Trembley, among his many experiments on the reproductive power of the fresh-water polype, even turned the body inside out, like the reversed finger of a glove. Nevertheless the creature continued to live, and took food. This may be explained by a change of structure, the consequence of the violence of the experiment." If the translation here is correct, we cannot forbear our expression of astonish- | insects for the most part live on the juices ment that Van der Hoeven should have of plants and animals, and do not mastiwritten, and his editor have passed, such cate their food, the existence of salivary a sentence. The fact alleged is one we glands in them becomes à priori questionare much inclined to doubt; it is, how- able; more questionable when we learn ever, almost universally accepted, and the that in the enormous order of Coleoptera ordinary and plausible explanation is this: they are for the most part wanting; and the lining membrane of the intestinal still more questionable when we learn that canal in all animals being only an infold- in the Ponorpa, among the Neuroptera, ing of the external envelope, the mucous the females have them not, whereas the membrane being a modification of the males are largely endowed with them! skin, no sooner is the polype turned in- If these glands are salivary the must perside out, than the external membrane form a simple function, accessory to the becomes modified into a mucous mem- function of digestion; and to suppose the brane, and the skin becomes an in- female takes her food in a different manner testinal canal. In point of strict ac- from the male, or digests it under differcuracy, there is no mucous membrane at ent conditions, is une très forte suppoall in the polype, but only a layer of sition. cells, indistinguishable from the layer which forms the external envelope; so that theoretically there is no difficulty in conceiving the fact to be as Trembley states it, and our skepticism does not fall on that part of the question, but on the preliminary fact of turning the polype inside out. What, however, can we say to a physiologist who believes in an external envelope being converted into an assimilative surface in consequence of undergoing violence from the experimenter! The reader may possible regard it as of little importance whether zoologists are right or wrong in the assignment of a function to these glands in insects; and in itself the error is harmless enough. Our protest is against the laxity which prevails throughout zoological investigations, and which suffers a bold guess to take the place of a rigorously verified observation. Why not let us acquiesce in ignorance, and say, "Here is an organ glandular in structure, function undeterAt pp. 255-7 we meet with statements mined?" The mere confession of ignowhich, in the present state of Physio- rance would direct investigation to the logy, require, to say the very least, a point; and if these investigations were more qualified expression before being controlled by inductive skepticism, the suffered to pass in the pages of a Hand- truth would finally appear. As an book. Thus we are told that in "very example of the laxity complained of, let many insects salivary glands are present; us consider the very next paragraph on they are placed at the commencement of the page before us. Van der Hoeven dethe intestinal canal." Most zoologists, scribes the fine vessels which are implantwe know, are not remarkable for cautioned below the inferior orifice of the in assigning functions to organs; but really, the supposition of insects possess ing salivary glands is one so opposed to any positive knowledge we have of the function of such glands in the higher animals, that until decisive evidence be brought forward proving that these glands are salivary, we must regard this hypothetical determination with extreme suspicion. The office of salivary glands is now ascertained to be simply that of facilitating deglutition by moistening the food and lubricating the passage into the stomach at least in the higher animals this is proved to be so by Claude Bernard's investigations.* Now, seeing that * Leçons de Physiologie Expérimentale. Paris, 1856. stomach-the so-called Malpighian vessels-which were formerly held to represent the liver, and are now supposed to represent the kidneys; and he remarks: "If we consider these organs as kidneys, it becomes uncertain whether insects have a liver; for the idea that these vessels may represent at once both kidneys and liver (whence it has been proposed to name them then vasa urino-biliaria) is not, as appears to me, the result of comphysiological, and would never have been enparative investigation, either anatomical or tertained but for the attempt to reconcile two conflicting views, and which ought always to be distrusted when it interferes with more extended inquiry." Not only two conflicting views, but two diametrically opposite functions, are "reconciled" by this attempt. The excretion of urea is physiologically and anatomically removed into a quite different category from the elaboration of bile; the urea is separated from the blood, the bile is constructed out of the blood; if the urea is not separated, it accumulates in the blood, and kills the animal; if the bile is not formed by the liver, no trace of its existence is discoverable in the blood; and although the function of digestion, with which the bile is some way connected, is doubtless troubled by this non-formation of bile, the animal shows no appreciable deterioration. Who does not see, therefore, that any attempt to unite two such functions in one organ is fundamentally unphilosophical? Van der Hoeven is puzzled at the absence of the liver, for, he says: "If we suppose it to be altogether wanting in insects, then it must be proved that the separation of bile [bile is not separated] is more important in the animal economy than the excretion of urea, before an argument can be borrowed therefrom against the function ascribed to the Malpighian vessels. We do not forget that by respiration and the elaboration of bile the quantity of carbon in the living body is diminished, and that from the large development of the respiratory organs in insects, the excretory office of the liver is in a great measure dropped." Van der Hoeven here, throughout, assumes that the liver is an excretory organ-a point on which the highest authorities are divided, and on which we may say, that if bile is to be regarded as an excretion, it is only so after previously fulfilling the office of a secretion, and aiding in the digestion of food. "Nevertheless," says Van der Hoeven, "it is highly probable that parts whose function agrees with that of a liver are not altogether absent in insects." We think so too, for in the larvæ of gnats we have detected the unmistakeable hepatic cells; but while agreeing with our author in the general statement, we read with considerable surprise the explanation he furnishes: "In the first place (he says), we might here refer to the great quantity of fat situated betwen the skin and the intestine, which invests every organ, and is of very great extent, more especially in larvæ, whose respiration is less perfect; the carbon and hydrogen, which in other instances is combined with oxygen to quit the body by respiration, here forms that provision of combustible matter so necessary in the animal economy for the support of respiration." On the strength of this he adopts Oken's hypothesis of the fat being the analogue of a liver! It is perfectly consistent with the Natur-philosophie to make such comparisons; but that a sober zoologist should for one moment consent to confound things so essentially distinct as a liver and a mass of fat, on the hypothetical assumption that both exert the same influence on the composition of the fluids, is enough to "give us pause." There are some anatomical inaccuracies which are easily removable; such, for instance, as the assertion, p. 91, that the ovaries of the Actinic open into the base of the stomach by efferent canals, there being no canals whatever in the Actinia; or such as the mistake, at p. 99, where the Acalepha, which do not sting, are said to be without thread-cells. But far more serious than errors of this kind is the omission of all reference whatever to the chylaqueous circulation in the Annelids, and to the masterly investigations of Dr. Williams of Swansea, published in the Reports of the British Association. But we must not continue our objections, or we shall convey a false impression of the substantial value of this work, which is one every zoological student should be glad to have upon his shelves for reference. There is no work on such an extensive and fluctuating body of details in which criticism would be unable to find errors; but there is, we believe, no work known to European zoologists which enjoys a higher reputation for accuracy than this Handbook by Van der Hoeven. BY-WAYS OF HISTORY.-"THE TWO BACONS." I HAVE read a story somewhere of a continually, that men of our day trade and coarse, rude fellow who, being in the room thrive, and make a show, and win a repute, with a man having a misshaped limb, fixed upon a capital of wisdom which in reality his eye upon it, saying, loudly and offen- consists of gold grains gathered from the sively, "That's the the ugliest leg in com- mine of Bacon's conceptions, and beat out pany!" To this insult, the other calmly into their thin lamina-finding this, I say, replied by offering a wager that "it was one does not not willingly think that any not," which being accepted, he put for- meanness, much less the debasing love of ward from under his cloak his other leg,"filthy lucre," could have lodged in that uglier and more deformed still. I apply this story to the case of the "two Bacons." If we must accept Pope's antithetic couplet, calling on us to "mark how Bacon shined, The wisest, brightest, meanest of mankind." fine and clear intellect, that lofty, capacious understanding. True! Bacon stands convicted at the bar of public judgment, upon an undefended charge, of sordid corruption, and yet one tithe of the investi gating care which is now-a-days so freely wasted in mawkish mercy upon many a case of glaring criminality, might, if applied to Bacon's case, very probably have long since, we will not say extenuated the offense, but reversed the verdict. as really descriptive of the great ex-Chancellor's character, I am disposed to think that there may be found hidden "in the cloak of history" a meaner man than" the The anecdote is well known, that as meanest," in the person of his brother, Bacon passed, in the course of his harassAnthony Bacon-an individual described ing and degrading trial, through the ranks as of more "parts" than "action," "nim- of his household standing ranged in the ble of head" as he was "impotent of feet" -and who contrived to climb to the very heights of "great affairs," and dive into the depts of dark intrigue, though he lay "bed-rid" all his lifetime! Before we go on with the comparison between the brothers, there are a few observations, gleaned here and there, to be offered in abatement of the condemnation generally passed on Bacon's memory and fame, as charged with venality in his high place as Chancellor. halls of his official residence at court, he bowed in bitterness to this show of respect from his official staff, and said briefly and pointedly, "Sit still, my masters, your rise hath been my fall"-being obviously understood to mean that he had found himself powerless to control or order his official "family" as he ought, and that in the transactions of which he was reaping the loss and disgrace, their corruption had "mastered" his powers of observation or of right rule. The force of his excuse will Who will not lend a willing ear to every be lost on those who insist on weighing point of evidence which may tend to clear the usages of Bacon's official life in the the character of this pioneer of truth-this balance of our own times. A Judge of our "Prophet of Science"-this "man before day, charged with receiving bribes, would his age," whose grandly pathetic "Appeal be coldly listened to if, admitting that to Posterity" is every day more fully "the bribe had been received," he should affirmed in the Court of Public Opinion? urge that "his servant had committed it When we read his "Aphostric Essays," replete as they are with a wisdom which, new and wondrous in his time, has never yet become obsolete-finding, as we do VOL. XL.-NO. IV. without his consciousness;" but does it follow that such a plea was equally irrelevant in an age when "back-stairs" influence, and access to the ear of great men 34 |