The Atlantic Monthly, Volume 09, No. 53, March, 1862

“Look you,” he said to a servant in violet livery who was waiting by the door, “follow yonder Capuchin and bring me word where he abides.—He may be cracked,” he said to himself; “but, after all, one of his blood may be worth mending, and do us good service either in Florence or Milan. We must have him transferred to some convent here, where we can lay hands on him readily, if we want him.”

Meanwhile Father Francesco wends his way through many a dark and dingy street to an ancient Capuchin convent, where he finds brotherly admission. Weary and despairing is he beyond all earthly despair, for the very altar of his God seems to have failed him. He asked for bread, and has got a stone,—he asked a fish, and has got a scorpion. Again and again the worldly, almost scoffing, tone of the superior to whom he has been confessing sounds like the hiss of a serpent in his ear.

But he is sent for in haste to visit the bedside of the Prior, who has long been sick and failing, and who gladly embraces this opportunity to make his last confession to a man of such reputed sanctity in his order as Father Francesco. For the acute Father Johannes, casting about for various means to empty the Superior’s chair at Sorrento, for his own benefit, and despairing of any occasion of slanderous accusation, had taken the other tack of writing to Rome extravagant laudations of such feats of penance and saintship in his Superior as in the view of all the brothers required that such a light should no more be hidden in an obscure province, but be set on a Roman candlestick, where it might give light to the faithful in all parts of the world. Thus two currents of worldly intrigue were uniting to push an unworldly man to a higher dignity than he either sought or desired.

When a man has a sensitive or sore spot in his heart, from the pain of which he would gladly flee to the ends of the earth, it is marvellous what coincidences of events will be found to press upon it wherever he may go. Singularly enough, one of the first items in the confession of the Capuchin Superior related to Agnes, and his story was in substance as follows. In his youth he had been induced by the persuasions of the young son of a great and powerful family to unite him in the holy sacrament of marriage with a protégée of his mother’s; but the marriage being detected, it was disavowed by the young nobleman, and the girl and her mother chased out ignominiously, so that she died in great misery. For his complicity in this sin the conscience of the monk had often troubled him, and he had kept track of the child she left, thinking perhaps some day to make reparation by declaring the true marriage of her mother, which now he certified upon the holy cross, and charged Father Francesco to make known to one of that kin whom he named. He further informed him, that this family, having fallen under the displeasure of the Pope and his son, Cæsar Borgia, had been banished from the city, and their property confiscated, so that there was none of them to be found thereabouts except an aged widowed sister, who, having married into a family in favor with the Pope, was allowed to retain her possessions, and now resided in a villa near Rome, where she lived retired, devoting her whole life to works of piety. The old man therefore conjured Father Francesco to lose no time in making this religious lady understand the existence of so near a kinswoman, and take her under her protection.—Thus strangely did Father Francesco find himself again obliged to take up that enchanted thread which had led him into labyrinths so fatal to his peace.

METHODS OF STUDY IN NATURAL HISTORY

V

It is in the search after the true boundaries and characteristics of orders that we may expect the greatest advance by the naturalists of the present day; and yet there is now much discrepancy among them, some mistaking orders for classes, others raising families to the dignity of orders. This want of agreement in their results is not strange, however; for the recognition of orders is indeed exceedingly difficult. If they are, as I have defined them, groups in Nature founded upon a greater or less complication of structure, they must of course form a regular gradation within the limits of their class, since comparative perfection implies comparative rank, and a correct estimate of these degrees of complication requires an intimate and extensive knowledge of structure throughout the class. There would seem to be an arbitrary element here,—that of our individual appreciation of structural character. If one man holds a certain kind of structural characters superior to another, he will establish the rank of the order upon that feature, while some other naturalist, appreciating a different point of the structure more highly, will make that the test character of the group. Let us see whether we can eliminate this arbitrary element in our estimate of these groups, and find any mode of determining orders that shall be unquestionable, and give us results as positive as a chemical analysis according to quantitative elements. I believe that there are such absolute tests of structural relations. It is my conviction, that orders, like all the other groups of the Animal Kingdom, have a positive existence in Nature with definite limits, that no arbitrary element should enter into any part of our classifications, and that we have already the key by which to solve this question about orders.

To illustrate this statement, I must return to the class of Insects. We have seen that they are divided into three orders: the long cylindrical Centipedes, with the body divided throughout in uniform rings, like the Worms; the Spiders, with the body divided into two regions; and the Winged Insects, with head, chest, and hind body distinct from each other, forming three separate regions. In the first group, the Centipedes, the nervous system is scattered through the whole body, as in the Worms; in the Spiders it is concentrated in two nervous swellings, as in the Crustacea, the front one being the largest; and in the Insects there are three nervous centres, the largest in the head, a smaller one in the chest, and the smallest in the hind body. Now according to this greater or less individualization of parts, with the corresponding localization of the nervous centres, naturalists have established the relative rank of these three groups, placing Centipedes lowest, Spiders next, and Winged Insects highest. But naturalists may, and indeed they actually do, differ as to this estimation of the anatomical structure. Have we, then, any means of testing its truth to Nature? Let us look at the development of these animals, taking the highest order as an illustration, that we may have the whole succession of changes. All know the story of the Butterfly with its three lives, as Caterpillar, Chrysalis, and Winged Insect. I speak of its three lives, but we must not forget that they make after all but one life, and that the Caterpillar is as truly the same being with the future Butterfly as the child is the same being with the future man. The old significance of the word metamorphosis—the fabled transformation of one individual into another, in which so much of the imagination and poetical culture of the ancients found expression—still clings to us; and where the different phases of the same life assume such different external forms, we are apt to overlook the fact that it is one single continuous life. To a naturalist, metamorphosis is simply growth; and in that sense the different stages of development in animals that undergo their successive changes within the egg are as much metamorphoses as the successive phases of life in those animals that complete their development after they are hatched.

But to return to our Butterfly. In its most imperfect, earliest condition, it is Worm-like, the body consisting of thirteen uniform rings; but when it has completed this stage of its existence, it passes into the Chrysalis state, during which the body has two regions, the front rings being soldered together to form the head and chest, while the hind joints remain distinct; and it is only when it bursts from its Chrysalis envelope, as a complete Winged Insect, that it has three distinct regions of the body. Do not the different periods of growth in this highest order explain the relation of all the orders to each other? The earliest condition of an animal cannot be its highest condition,—it does not pass from a more perfect to a less perfect state of existence. The history of its growth is, on the contrary, the history of its progress in development; and therefore, when we find that the first stage of growth in the Winged Insect transiently represents a structural character that is permanent in the lowest order of its class, that its second stage of growth transiently represents a structural character that is permanent in the second order of its class, and that only in the last stage of its existence does the Winged Insect attain its complete and perfect condition, we may fairly infer that this division of the class of Insects into a gradation of orders placing Centipedes lowest, Spiders next, and Winged Insects highest, is true to Nature.

This is not the only instance in which the embryological evidence confirms perfectly the anatomical evidence on which orders have been distinguished, and I believe that Embryology will give us the true standard by which to test the accuracy of our ordinal groups. In the class of Crustacea, for instance, the Crabs have been placed above the Lobsters by some naturalists, in consequence of certain anatomical features; but there may easily be a difference of individual opinion as to the relative value of these features. When we find, however, that the Crab, while undergoing its changes in the egg, passes through a stage in which it resembles the Lobster much more than it does its own adult condition, we cannot doubt that its earlier state is its lower one, and that the organization of the Lobster is not as high in the class of Crustacea as that of the Crab. While using illustrations of this kind, however, I must guard against misinterpretation. These embryological changes are never the passing of one kind of animal into another kind of animal: the Crab is none the less a Crab during that period of its development in which it resembles a Lobster; it simply passes, in the natural course of its growth, through a phase of existence which is permanent in the Lobster, but transient in the Crab. Such facts should stimulate all our young students to embryological investigation as a most important branch of study in the present state of our science.

But while there is this structural gradation among orders, establishing a relative rank between them, are classes and branches also linked together as a connected chain? That such a chain exists throughout the Animal Kingdom has long been a favorite idea, not only among naturalists, but also in the popular mind. Lamarck was one of the greatest teachers of this doctrine. He held not only that branches and classes were connected in a direct gradation, but that within each class there was a regular series of orders, families, genera, and species, forming a continuous chain from the lowest animals to the highest, and that the whole had been a gradual development of higher out of lower forms. I have already alluded to his division of the Animal Kingdom into the Apathetic, Sensitive, and Intelligent animals. The Apathetic were those devoid of all sensitiveness except when aroused by the influence of some external agent. Under this head he placed five classes, including the Infusoria, Polyps, Star-Fishes, Sea-Urchins, Tunicata, and Worms,—thus bringing together indiscriminately Radiates, Mollusks, and Articulates. Under the head of Sensitive he had also a heterogeneous assemblage, including Winged Insects, Spiders, Crustacea, Annelids, and Barnacles, all of which are Articulates, and with these he placed in two classes the Mollusks, Conchifera, Gasteropoda, and Cephalopoda. Under the head of Intelligent he brought together a natural division, for he here united all the Vertebrates. He succeeded in this way in making out a series which seemed plausible enough, but when we examine it, we find at once that it is perfectly arbitrary; for he has brought together animals built on entirely different structural plans, when he could find characters among them that seemed to justify his favorite idea of a gradation of qualities. Blainville attempted to establish the same idea in another way. He founded his series on gradations of form, placing together, in one division, all animals that he considered vague and indefinite in form, and in another all those that he considered symmetrical. Under a third head he brought together the Radiates; but his symmetrical division united Articulates, Mollusks, and Vertebrates in the most indiscriminate manner. He sustained his theory by assuming intermediate groups,—as, for instance, the Barnacles between the Mollusks and Articulates, whereas they are as truly Articulates as Insects or Crabs. Thus, by misplacing certain animals, he arrived at a series which, like that of Lamarck, made a strong impression on the scientific world, till a more careful investigation of facts exposed its fallacy.

Oken, the great German naturalist, also attempted to establish a connected chain throughout the Animal Kingdom, but on an entirely different principle; and I cannot allude to this most original investigator, so condemned by some, so praised by others, so powerful in his influence on science in Germany, without attempting to give some analysis of his peculiar philosophy. For twenty years his classification was accepted by his countrymen without question; and though I believe it to be wrong, yet, by the ingenuity with which he maintained it, he has shed a flood of light upon science, and has stimulated other naturalists to most important and interesting investigations. This famous classification was founded upon the idea that the system of man, the most perfect created being, is the measure for the whole Animal Kingdom, and that in analyzing his organization we have the clue to all organized beings. The structure of man includes two systems of organs: those which maintain the body in its integrity, and which he shares in some sort with the lower animals,—the organs of digestion, circulation, respiration, and reproduction; and that higher system of organs, the brain, spinal marrow, and nerves, with the organs of sense, on which all the manifestations of the intelligent faculties depend, and by which his relations to the external world are established and controlled: the whole being surrounded by flesh, muscles, and skin. On account of this fleshy envelope of the hard parts in all the higher animals, Oken divided the Animal Kingdom into two groups, the Vertebrates and Invertebrates, or, as he called them, the “Eingeweide und Fleisch Thiere”—which we may translate as the Intestinal Animals, or those that represent the intestinal systems of organs, and the Flesh Animals, or those that combine all the systems of organs under one envelope of flesh. Let us examine a little more closely this singular theory, by which each branch of the Invertebrates becomes, as it were, the exponent of a special system of organs, while the Vertebrates, with man at their head, include all these systems.

According to Oken, the Radiates, the lowest type of the Animal Kingdom, embody digestion. They all represent a stomach, whether it is the simple sac of the Polyps, or the cavity of the Acalephs, with its radiating tubes traversing the gelatinous mass of the body, or the cavity and tubes of the Echinoderms, inclosed within walls of their own.

The Mollusks represent circulation; and his division of this type into classes, according to what he considers the higher or lower organization of the heart, agrees with the ordinary division into Acephala, Gasteropoda, and Cephalopoda.

The Articulates are the respiratory animals in this classification: they represent respiration. The Worms, breathing, as he asserts, through the whole surface of the skin, without special breathing organs, are the lowest; the Crustacea, with gills, or aquatic breathing organs, come next; and he places the Insects highest, with their branching tracheæ, admitting air to all parts of the body. The Vertebrates, or Flesh Animals, with their four classes, represent the Bones, the Muscles, the Nerves, and the Organs of Sense.

This theory, according to which there are as many great divisions as there are structural systems or combinations of systems in the Animal Kingdom, seemed natural and significant, and there was something attractive in the idea that man represents, as it were, the synthetic combination of all these different systems. Oken also, in his exposition of his mode of classification, showed an insight into the structure and relations of animals that commended it to the interest of all students of Nature, and entitles him to their everlasting gratitude. Nevertheless, his theory fails, when it is compared with facts. For instance, there are many Worms that have no respiration through the skin, while his appreciation of the whole class is founded on that feature; and in his type representing circulation, the Mollusks, there are those that have no heart at all. It would carry me too far into scientific details, were I to explain all the points at which this celebrated classification fails. Suffice it to say that there is no better proof of the discrepancy between the system and the facts than the constant changes in the different editions of Oken’s own works and in the publications of his followers founded upon his views, showing that they were themselves conscious of the shifting and unstable character of their scientific ground.

VI

What, then, is the relation of these larger groups to each other, if they do not stand in a connected series from the lowest to the highest? How far are each of the branches and each of the classes superior or inferior one to another? All agree, that, while Vertebrates stand at the head of the Animal Kingdom, Radiates are lowest. There can be no doubt upon this point; for, while the Vertebrate plan, founded upon a double symmetry, includes the highest possibilities of animal organization, there is a certain monotony of structure in the Radiate plan, in which the body is divided into a number of identical parts, bearing definite relations to a central vertical axis. But while all admit that Vertebrates are highest and Radiates lowest, how do the Articulates and Mollusks stand to these and to each other? To me it seems, that, while both are decidedly superior to the Radiates and inferior to the Vertebrates, we cannot predicate absolute superiority or inferiority of organization of either of these groups as compared with each other; they stand on one structural level, though with different tendencies,—the body in Mollusks having always a soft, massive, concentrated character, with great power of contraction and dilatation, while the body in Articulates has nothing of this compactness and concentration, but on the contrary is usually marked by a conspicuous external display of limbs and other appendages, and by a remarkable elongation of the body,—that feature characterized by Baer when he called them the Longitudinal type. There is in the Articulates an extraordinary tendency toward outward expression, singularly in contrast to the soft, contractile bodies of the Mollusks. We need only remember the numerous Insects with small bodies and enormously long wings, or the Spiders with little bodies and long legs, or the number and length of the claws in the Lobsters and Crabs, as illustrations of this statement for the Articulates, while the soft compact body of the Oyster or of the Snail is equally characteristic of the Mollusks; and though it may seem that this assertion cannot apply to the highest class of Mollusks, the Cephalopoda, including the Cuttle-Fishes with their long arms or feelers, yet even these conspicuous appendages have considerable power of contraction and dilatation, and in the Nautili may even be drawn completely within the shell. If this view be correct, these two types occupy an intermediate position between the highest and the lowest divisions of the Animal Kingdom, but are on equal ground when compared with each other.

But is there a transition from Radiates to Mollusks, or from Articulates to Vertebrates, or from any one of these divisions into any other? Let us first consider the classes as they stand within their divisions. We have seen that there are three classes of Radiates,—Polyps, Acalephs, and Echinoderms; three classes of Mollusks,—Acephala, Gasteropoda, and Cephalopoda; three classes of Articulates,—Worms, Crustacea, and Insects; and, according to the usually accepted classification, four classes of Vertebrates,—Fishes, Reptiles, Birds, and Mammalia. If there is indeed a transition between all these classes, it must become clear to us, when we have accurately interpreted their relative standing. Taking first the lowest branch, how do the classes stand within the limits of the type of Radiates? I think I have said enough of these different classes to show that Polyps as a whole are inferior to Acalephs as a whole, and that Acalephs as a whole are inferior to Echinoderms as a whole. But if they are linked together as a connected series, then the lowest Acaleph should stand next in structure above the highest Polyp, and the lowest Echinoderm next above the highest Acaleph. So far from this being the case, there are, on the contrary, many Acalephs which, in their specialization, are unquestionably lower in the scale of life than some Polyps, while there are some Echinoderms lower in the same sense than many Acalephs. This remark applies equally to the classes within the other types; they stand, as an average, relatively to each other, lower and higher, but considered in their diversified specification, there are some members of the higher classes that are inferior in organization to some members of the lower classes. The same is true of the great divisions as compared with each other. Instead of the highest Radiates being always lower in organization than the lowest Mollusks, there are many Star-Fishes and Sea-Urchins higher in organization than some Mollusks; and so when we pass from this branch to the Articulates, if we assume for the moment, as some naturalists believe, that the Mollusks are the inferior type, the Cuttle-Fishes are certainly very superior animals to most of the Worms; and passing from Articulates to Vertebrates, not only are there Insects of a more complex organization than the lowest Fishes, but we bring together two kinds of animals so remote from each other in structure that the wildest imagination can scarcely fancy a transition between them. A comparison may make my meaning clearer as to the relative standing of these groups. The Epic Poem is a higher order of composition than the Song,—yet we may have an Epic Poem which, from its inferior mode of execution, stands lower than a Song that is perfect of its kind. So the plan of certain branches is more comprehensive and includes higher possibilities than that of others, while at the same time there may be species in which the higher plan is executed in so simple a manner that it places their organization below some more highly developed being built on a lower plan. It is a poor comparison, because everything that God has made is perfect of its kind and in its place, though relatively lower or higher; yet it is only by comparison of what is after all akin,—of mind with mind,—even though so far apart as the works of the divine and the human reason, that we may arrive at some idea, however dim, of the mental operations of the Creative Intellect.

It is, then, in their whole bulk that any one of these groups is above any other. We may represent the relative positions of the classes by a diagram in which each successive class in every type starts at a lower point than that at which the preceding class closes. Taking the Polyps as the lowest class of Radiates, for instance, its highest animals rise above the lowest members of the Acalephs, but then the higher members of the class of Acalephs reach a point far above any of the Polyps,—and so on.

If this view be correct, it sets aside the possibility of any uninterrupted series based on absolute superiority or inferiority of structure, on which so much ingenuity and intellectual power have been wasted.