The Atlantic Monthly, Volume 09, No. 54, April, 1862

The most welcome of companions, this plain countryman. One shall not meet with thoughts invigorating like his often; coming so scented of mountain and field breezes and rippling springs, so like a luxuriant clod from under forest-leaves, moist and mossy with earth-spirits. His presence is tonic, like ice-water in dog-days to the parched citizen pent in chambers and under brazen ceilings. Welcome as the gurgle of brooks, the dripping of pitchers,—then drink and be cool! He seems one with things, of Nature's essence and core, knit of strong timbers, most like a wood and its inhabitants. There are in him sod and shade, woods and waters manifold, the mould and mist of earth and sky. Self-poised and sagacious as any denizen of the elements, he has the key to every animal's brain, every plant, every shrub; and were an Indian to flower forth, and reveal the secrets hidden in his cranium, it would not be more surprising than the speech of our Sylvanus. He must belong to the Homeric age,—is older than pastures and gardens, as if he were of the race of heroes, and one with the elements. He, of all men, seems to be the native New-Englander, as much so as the oak, the granite ledge, our best sample of an indigenous American, untouched by the Old Country, unless he came down from Thor, the Northman; as yet unfathered by any, and a nondescript in the books of natural history.

A peripatetic philosopher, and out of doors for the best parts of his days and nights, he has manifold weather and seasons in him, and the manners of an animal of probity and virtues unstained. Of our moralists he seems the wholesomest; and the best republican citizen in the world,—always at home, and minding his own affairs. Perhaps a little over-confident sometimes, and stiffly individual, dropping society clean out of his theories, while standing friendly in his strict sense of friendship, there is in him an integrity and sense of justice that make possible and actual the virtues of Sparta and the Stoics, and all the more welcome to us in these times of shuffling and of pusillanimity. Plutarch would have made him immortal in his pages, had he lived before his day. Nor have we any so modern as be,—his own and ours; too purely so to be appreciated at once. A scholar by birthright, and an author, his fame has not yet travelled far from the banks of the rivers he has described in his books; but I hazard only the truth in affirming of his prose, that in substance and sense it surpasses that of any naturalist of his time, and that he is sure of a reading in the future. There are fairer fishes in his pages than any now swimming in our streams, and some sleep of his on the banks of the Merrimack by moonlight that Egypt never rivalled; a morning of which Memnon might have envied the music, and a greyhound that was meant for Adonis; some frogs, too, better than any of Aristophanes. Perhaps we have had no eyes like his since Pliny's time. His senses seem double, giving him access to secrets not easily read by other men: his sagacity resembling that of the beaver and the bee, the dog and the deer; an instinct for seeing and judging, as by some other or seventh sense, dealing with objects as if they were shooting forth from his own mind mythologically, thus completing Nature all round to his senses, and a creation of his at the moment. I am sure he knows the animals, one by one, and everything else knowable in our town, and has named them rightly as Adam did in Paradise, if he be not that ancestor himself. His works are pieces of exquisite sense, celebrations of Nature's virginity, exemplified by rare learning and original observations. Persistently independent and manly, he criticizes men and times largely, urging and defending his opinions with the spirit and pertinacity befitting a descendant of him of the Hammer. A head of mixed genealogy like his, Franco-Norman crossed by Scottish and New-England descent, may be forgiven a few characteristic peculiarities and trenchant traits of thinking, amidst his great common sense and fidelity to the core of natural things. Seldom has a head circumscribed so much of the sense of Cosmos as this footed intelligence,—nothing less than all out-of-doors sufficing his genius and scopes, and, day by day, through all weeks and seasons, the year round.

If one would find the wealth of wit there is in this plain man, the information, the sagacity, the poetry, the piety, let him take a walk with him, say of a winter's afternoon, to the Blue Water, or anywhere about the outskirts of his village-residence. Pagan as he shall outwardly appear, yet he soon shall be seen to be the hearty worshipper of whatsoever is sound and wholesome in Nature,—a piece of russet probity and sound sense that she delights to own and honor. His talk shall be suggestive, subtile, and sincere, under as many masks and mimicries as the shows he passes, and as significant,—Nature choosing to speak through her chosen mouth-piece,—cynically, perhaps, sometimes, and searching into the marrows of men and times he chances to speak of, to his discomfort mostly, and avoidance. Nature, poetry, life,—not politics, not strict science, not society as it is,—are his preferred themes: the new Pantheon, probably, before he gets far, to the naming of the gods some coming Angelo, some Pliny, is to paint and describe. The world is holy, the things seen symbolizing the Unseen, and worthy of worship so, the Zoroastrian rites most becoming a nature so fine as ours in this thin newness, this worship being so sensible, so promotive of possible pieties,—calling us out of doors and under the firmament, where health and wholesomeness are finely insinuated into our souls,—not as idolaters, but as idealists, the seekers of the Unseen through images of the Invisible.

I think his religion of the most primitive type, and inclusive of all natural creatures and things, even to "the sparrow that falls to the ground,"—though never by shot of his,—and, for whatsoever is manly in man, his worship may compare with that of the priests and heroes of pagan times. Nor is he false to these traits under any guise,—worshipping at unbloody altars, a favorite of the Unseen, Wisest, and Best. Certainly he is better poised and more nearly self-reliant than other men.

Perhaps he deals best with matter, properly, though very adroitly with mind, with persons, as he knows them best, and sees them from Nature's circle, wherein he dwells habitually. I should say he inspired the sentiment of love, if, indeed, the sentiment he awakens did not seem to partake of a yet purer sentiment, were that possible,—but nameless from its excellency. Friendly he is, and holds his friends by bearings as strict in their tenderness and consideration as are the laws of his thinking,—as prompt and kindly equitable,—neighborly always, and as apt for occasions as he is strenuous against meddling with others in things not his.

I know of nothing more creditable to his greatness than the thoughtful regard, approaching to reverence, by which he has held for many years some of the best persons of his time, living at a distance, and wont to make their annual pilgrimage, usually on foot, to the master,—a devotion very rare in these times of personal indifference, if not of confessed unbelief in persons and ideas.

He has been less of a housekeeper than most, has harvested more wind and storm, sun and sky; abroad night and day with his leash of keen scents, bounding any game stirring, and running it down, for certain, to be spread on the dresser of his page, and served as a feast to the sound intelligences, before he has done with it. We have been accustomed to consider him the salt of things so long that they must lose their savor without his to season them. And when he goes hence, then Pan is dead, and Nature ailing throughout.

His friend sings him thus, with the advantages of his Walden to show him in Nature:—

"It is not far beyond the Village church,
After we pass the wood that skirts the road,
A Lake,—the blue-eyed Walden, that doth smile
Most tenderly upon its neighbor Pines;
And they, as if to recompense this love,
In double beauty spread their branches forth.
This Lake has tranquil loveliness and breadth,
And, of late years, has added to its charms;
For one attracted to its pleasant edge
Has built himself a little Hermitage,
Where with much piety he passes life.

"More fitting place I cannot fancy now,
For such a man to let the line run off
The mortal reel,—such patience hath the Lake,
Such gratitude and cheer is in the Pines.
But more than either lake or forest's depths
This man has in himself: a tranquil man,
With sunny sides where well the fruit is ripe,
Good front and resolute bearing to this life,
And some serener virtues, which control
This rich exterior prudence,—virtues high,
That in the principles of Things are set,
Great by their nature, and consigned to him,
Who, like a faithful Merchant, does account
To God for what he spends, and in what way.
Thrice happy art thou, Walden, in thyself!
Such purity is in thy limpid springs,—
In those green shores which do reflect in thee,
And in this man who dwells upon thy edge,
A holy man within a Hermitage.
May all good showers fall gently into thee,
May thy surrounding forests long be spared,
And may the Dweller on thy tranquil marge
There lead a life of deep tranquillity,
Pure as thy Waters, handsome as thy Shores,
And with those virtues which are like the Stars!"

METHODS OF STUDY IN NATURAL HISTORY

VII

I come now to an obscure part of my subject, very difficult to present in a popular form, and yet so important in the scientific investigations of our day that I cannot omit it entirely. I allude to what are called by naturalists Collateral Series or Parallel Types. These are by no means difficult to trace, because they are connected by seeming resemblances, which, though very likely to mislead and perplex the observer, yet naturally suggest the association of such groups. Let me introduce the subject with the statement of some facts.

There are in Australia numerous Mammalia, occupying the same relation and answering the same purposes as the Mammalia of other countries. Some of them are domesticated by the natives, and serve them with meat, milk, wool, as our domesticated animals serve us. Representatives of almost all types, Wolves, Foxes, Sloths, Bears, Weasels, Martens, Squirrels, Rats, etc., are found there; and yet, though all these animals resemble ours so closely that the English settlers have called many of them by the same names, there are no genuine Wolves, Foxes, Sloths, Bears, Weasels, Martens, Squirrels, or Rats in Australia. The Australian Mammalia are peculiar to the region where they are found, and are all linked together by two remarkable structural features which distinguish them from all other Mammalia and unite them under one head as the so-called Marsupials. They bring forth their young in an imperfect condition, and transfer them to a pouch, where they remain attached to the teats of the mother till their development is as far advanced as that of other Mammalia at the time of their birth; and they are further characterized by an absence of that combination of transverse fibres forming the large bridge which unites the two hemispheres of the brain in all the other members of their class. Here, then, is a series of animals parallel with ours, separated from them by anatomical features, but so united with them by form and external features that many among them have been at first associated together.

This is what Cuvier has called subordination of characters, distinguishing between characters that control the organization and those that are not essentially connected with it. The skill of the naturalist consists in detecting the difference between the two, so that he may not take the more superficial features as the basis of his classification, instead of those important ones which, though often less easily recognized, are more deeply rooted in the organization. It is a difference of the same nature as that between affinity and analogy, to which I have alluded before, when speaking of the ingrafting of certain features of one type upon animals of another type, thus producing a superficial resemblance, not truly characteristic. In the Reptiles, for instance, there are two groups,—those devoid of scales, with naked skin, laying numerous eggs, but hatching their young in an imperfect state, and the Scaly Reptiles, which lay comparatively few eggs, but whose young, when hatched, are completely developed, and undergo no subsequent metamorphosis. Yet, notwithstanding this difference in essential features of structure, and in the mode of reproduction and development, there is such an external resemblance between certain animals belonging to the two groups that they were associated together even by so eminent a naturalist as Linnaeus. Compare, for instance, the Serpents among the Scaly Reptiles with the Caecilians among the Naked Reptiles. They have the same elongated form, and are both destitute of limbs; the head in both is on a level with the body, without any contraction behind it, such as marks the neck in the higher Reptiles, and moves only by the action of the back-bone; they are singularly alike in their external features, but the young of the Serpent are hatched in a mature condition, while the young of the type to which the Caecilians belong undergo a succession of metamorphoses before attaining to a resemblance to the parent. Or compare the Lizard and the Salamander, in which the likeness is perhaps even more striking; for any inexperienced observer would mistake one for the other. Both are superior to the Serpents and Caecilians, for in them the head moves freely on the neck and they creep on short imperfect legs. But the Lizard is clothed with scales, while the body of the Salamander is naked, and the young of the former is complete when hatched, while the Tadpole born from the Salamander has a life of its own to live, with certain changes to pass through before it assumes its mature condition; during the early part of its life it is even destitute of legs, and has gills like the Fishes. Above the Lizards and Salamanders, highest in the class of Reptiles, stand two other collateral types,—the Turtles at the head of the Scaly Reptiles, the Toads and Frogs at the Lead of the Naked Reptiles. The external likeness between these two groups is perhaps less striking than between those mentioned above, on account of the large shield of the Turtle. But there are Turtles with a soft covering, and there are some Toads with a hard shield over the head and neck at least, and both groups are alike distinguished by the shortness and breadth of the body and by the greater development of the limbs as compared with the lower Reptiles. But here again there is the same essential difference in the mode of development of their young as distinguishes all the rest. The two series may thus be contrasted:—

Naked Reptiles. Toads and Frogs, Salamanders, Caecilians.

Scaly Reptiles. Turtles, Lizards, Serpents.

Such corresponding groups or parallel types, united only by external resemblance, and distinguished from each other by essential elements of structure, exist among all animals, though they are less striking among Birds on account of the uniformity of that class. Yet even there we may trace such analogies,—as between the Palmate or Aquatic Birds, for instance, and the Birds of Prey, or between the Frigate Bird and the Kites. Among Fishes such analogies are very common, often suggesting a comparison even with land animals, though on account of the scales and spines of the former the likeness may not be easily traced. But the common names used by the fishermen often indicate these resemblances, —as, for instance, Sea-Vulture, Sea-Eagle, Cat-Fish, Flying-Fish, Sea-Porcupine, Sea-Cow, Sea-Horse, and the like. In the branch of Mollusks, also, the same superficial analogies are found. In the lowest class of this division of the Animal Kingdom there is a group so similar to the Polyps, that, until recently, they have been associated with them,—the Bryozoa. They are very small animals, allied to the Clams by the plan of their structure, but they have a resemblance to the Polyps on account of a radiating wreath of feelers around the upper part of their body: yet, when examined closely, this wreath is found to be incomplete; it does not, form a circle, but leaves an open space between the two ends, where they approach each other, so that it has a horseshoe outline, and partakes of the bilateral symmetry characteristic of its type and on which its own structure is based. These series have not yet been very carefully traced, and young naturalists should turn their attention to them, and be prepared to draw the nicest distinction between analogies and true affinities among animals.

VIII

After this digression, let us proceed to a careful examination of the natural groups of animals called Families by naturalists,—a subject already briefly alluded to in a previous chapter. Families are natural assemblages of animals of less extent than Orders, but, like Orders, Classes, and Branches, founded upon certain categories of structure, which are as distinct for this kind of group as for all the other divisions in the classification of the Animal Kingdom.

That we may understand the true meaning of these divisions, we must not be misled by the name given by naturalists to this kind of group. Here, as in so many other instances, a word already familiar, and that had become, as it were, identified with the special sense in which it had been used, has been adopted by science and has received a new signification. When naturalists speak of Families among animals, they do not allude to the progeny of a known stock, as we designate, in common parlance, the children or the descendants of known parents by the word family; they understand by Families natural groups of different kinds of animals, having no genetic relations so far as we know, but agreeing with one another closely enough to leave the impression of a more or less remote common parentage. The difficulty here consists in determining the natural limits of such groups, and in tracing the characteristic features by which they may be defined; for individual investigators differ greatly as to the degree of resemblance existing between the members of many Families, and there is no kind of group which presents greater diversity of circumscription in the classifications of animals proposed by different naturalists than these so-called Families.

It should be remembered, however, that, unless a sound criterion be applied to the limitation of Families, they, like all other groups introduced into zoölogical systems, must forever remain arbitrary divisions, as they have been hitherto. A retrospective glance at the progress of our science during the past century, in this connection, may perhaps help us to solve the difficulty. Linnaeus, in his System of Nature, does not admit Families; he has only four kinds of groups,—Classes, Orders, Genera, and Species. It was among plants that naturalists first perceived those general traits of resemblance which exist everywhere among the members of natural families, and added this kind of group to the framework of their system. In France, particularly, this method was pursued with success; and the improvements thus introduced by the French botanists were so great, and rendered their classification so superior to that of Linnaeus, that the botanical systems in which Families were introduced were called natural systems, in contradistinction especially to the botanical classification of Linnaeus, which was founded upon the organs of reproduction, and which received thenceforth the name of the sexual system of plants. The same method so successfully used by botanists was soon introduced into Zoölogy by the French naturalists of the beginning of this century,—Lamarck, Latreille, and Cuvier. But, to this day, the limitation of Families among animals has not yet reached the precision which it has among plants, and I see no other reason for the difference than the absence of a leading principle to guide us in Zoölogy.

Families, as they exist in Nature, are based upon peculiarities of form as related to structure; but though a very large number of them have been named and recorded, very few are characterized with anything like scientific accuracy. It has been a very simple matter to establish such groups according to the superficial method that has been pursued, for the fact that they are determined by external outline renders the recognition of them easy and in many instances almost instinctive; but it is very difficult to characterize them, or, in other words, to trace the connection between form and structure. Indeed, many naturalists do not admit that Families are based upon form; and it was in trying to account for the facility with which they detect these groups, while they find it so difficult to characterize them, that I perceived that they are always associated with peculiarities of form. Naturalists have established Families simply by bringing together a number of animals resembling each other more or less closely, and, taking usually the name of the Genus to which the best known among them belongs, they have given it a patronymic termination to designate the Family, and allowed the matter to rest there, sometimes without even attempting any description corresponding to those by which Genus and Species are commonly defined.

For instance, from Canis, the Dog, Canidae has been formed, to designate the whole Family of Dogs, Wolves, Foxes, etc. Nothing can be more superficial than such a mode of classification; and if these groups actually exist in Nature, they must be based, like all the other divisions, upon some combination of structural characters peculiar to them. We have seen that Branches are founded upon the general plan of structure, Classes on the mode of executing the plan, Orders upon the greater or less complication of a given mode of execution, and we shall find that form, as determined by structure, characterizes Families. I would call attention to this qualification of my definition; since, of course, when speaking of form in this connection, I do not mean those superficial resemblances in external features already alluded to in my remarks upon Parallel or Collateral Types. I speak now of form as controlled by structural elements; and unless we analyze Families in this way, the mere distinguishing and naming them does not advance our science at all. Compare, for instance, the Dogs, the Seals, and the Bears. These are all members of one Order,—that of the Carnivorous Mammalia. Their dentition is peculiar and alike in all, (cutting teeth, canine teeth, and grinders,) adapted for tearing and chewing their food; and their internal structure bears a definite relation to their dentition. But look at these animals with reference to form. The Dog is comparatively slender, with legs adapted for running and hunting his prey; the Bear is heavier, with shorter limbs; while the Seal has a continuous uniform outline adapted for swimming. They form separate Families, and are easily recognized as such by the difference in their external outline; but what is the anatomical difference which produces the peculiarity of form in each, by which they have been thus distinguished? It lies in the structure of the limbs, and especially in that of the wrist and fingers. In the Seal the limbs are short, and the wrists are on one continuous line with them, so that it has no power of bending the wrist or the fingers, and the limbs, therefore, act like flappers or oars. The Bear has a well-developed paw with a flexible wrist, but it steps on the whole sole of the foot, from the wrist to the tip of the toe, giving it the heavy tread so characteristic of all the Bears. The Dogs, on the contrary, walk on tip-toe, and their step, though firm, is light, while the greater slenderness and flexibility of their legs add to their nimbleness and swiftness. By a more extensive investigation of the anatomical structure of the limbs in their connection with the whole body, it could easily be shown that the peculiarity of form in these animals is essentially determined by, or at least stands in the closest relation to, the peculiar structure of the wrist and fingers.

Take the Family of Owls as distinguished from the Falcons, Kites, etc. Here the difference of form is in the position of the eyes. In the Owl, the sides of the head are prominent and the eye-socket is brought forward. In the Falcons and Kites, on the contrary, the sides of the head are flattened and the eyes are set back. The difference in the appearance of the birds is evident to the most superficial observer; but to call the one Strigidae and the other Falconidae tells us nothing of the anatomical peculiarities on which this difference is founded.

These few examples, selected purposely among closely allied and universally known animals, may be sufficient to show, that, beyond the general complication of the structure which characterizes the Orders, there is a more limited element in the organization of animals, bearing chiefly upon their form, which, if it have any general application as a principle of classification, may well be considered as essentially characteristic of the Families. There are certainly closely allied natural groups of animals, belonging to the same Order, but including many Genera, which differ from each other chiefly in their form, while that form is determined by peculiarities of structure which do not influence the general structural complication upon which Orders are based, or relate to the minor details of structure on which Genera are founded. I am therefore convinced that form is the criterion by which Families may be determined. The great facility with which animals may be combined together in natural groups of this kind without any special investigation of their structure, a superficial method of classification in which zoölogists have lately indulged to a most unjustifiable degree, convinces me that it is the similarity of form which has unconsciously led such shallow investigators to correct results, since upon close examination it is found that a large number of the Families so determined, and to which no characters at all are assigned, nevertheless bear the severest criticism founded upon anatomical investigation.

The questions proposed to themselves by all students who would characterize Families should be these: What are, throughout the Animal Kingdom, the peculiar patterns of form by which Families are distinguished? and on what structural features are these patterns based? Only the most patient investigations can give us the answer, and it will be very long before we can write out the formulae of these patterns with mathematical precision, as I believe we shall be able to do in a more advanced stage of our science. But while the work is in progress, it ought to be remembered that a mere general similarity of outline is not yet in itself evidence of identity of form or pattern, and that, while seemingly very different forms may be derived from the same formula, the most similar forms may belong to entirely different systems, when their derivation is properly traced. Our great mathematician, in a lecture delivered at the Lowell Institute last winter, showed that in his science, also, similarity of outline does not always indicate identity of character. Compare the different circles,—the perfect circle, in which every point of the periphery is at the same distance from the centre, with an ellipse in which the variation from the true circle is so slight as to be almost imperceptible to the eye; yet the latter, like all ellipses, has its two foci by which it differs from a circle, and to refer it to the family of circles instead of the family of ellipses would be overlooking its true character on account of its external appearance; and yet ellipses may be so elongated, that, far from resembling a circle, they make the impression of parallel lines linked at their extremities. Or we may have an elastic curve in which the appearance of a circle is produced by the meeting of the two ends; nevertheless it belongs to the family of elastic curves, in which may even be included a line actually straight, and is formed by a process entirely different from that which produces the circle or the ellipse.

But it is sometimes exceedingly difficult to find the relation between structure and form in Families, and I remember a case which I had taken as a test of the accuracy of the views I entertained upon this subject, and which perplexed and baffled me for years. It was that of our fresh-water Mussels, the Family of Unios. There is a great variety of outline among them,—some being oblong and very slender, others broad with seemingly square outlines, others having a nearly triangular form, while others again are almost circular; and I could not detect among them all any feature of form that was connected with any essential element of their structure. At last, however, I found this test-character, and since that time I have had no doubt left in my mind that form, determined by structure, is the true criterion of Families. In the Unios it consists of the rounded outline of the anterior end of the body reflected in a more or less open curve of the shell, bending more abruptly along the lower side with an inflection followed by a bulging, corresponding to the most prominent part of the gills, to which alone, in a large number of American Species of this Family, the eggs are transferred, giving to this part of the shell a prominence which it has not in any of the European Species. At the posterior end of the body this curve then bends upwards and backwards again, the outline meeting the side occupied by the hinge and ligament, which, when very short, may determine a triangular form of the whole shell, or, when equal to the lower side and connected with a great height of the body, gives it a quadrangular form, or, if the height is reduced, produces an elongated form, or, finally, a rounded form, if the passage from one side to the other is gradual. A comparison of the position of the internal organs of different Species of Unios with the outlines of their shells will leave no doubt that their form is determined by the structure of the animal.

A few other and more familiar examples may complete this discussion. Among Climbing Birds, for instance, which are held together as a more comprehensive group by the structure of their feet and by other anatomical features, there are two Families so widely different in their form that they may well serve as examples of this principle. The Woodpeckers (Picidae) and the Parrots (Psittacidae), once considered as two Genera only, have both been subdivided, in consequence of a more intimate knowledge of their generic characters, into a large number of Genera; but all the Genera of Woodpeckers and all the Genera of the Parrots are still held together by their form as Families, corresponding as such to the two old Genera of Picus and Psittacus. They are now known as the Families of Woodpeckers and Parrots; and though each group includes a number of Genera combined upon a variety of details in the finish of special parts of the structure, such as the number of toes, the peculiarities of the bill, etc., it is impossible to overlook the peculiar form which is characteristic of each. No one who is familiar with the outline of the Parrot will fail to recognize any member of that Family by a general form which is equally common to the diminutive Nonpareil, the gorgeous Ara, and the high-crested Cockatoo. Neither will any one, who has ever observed the small head, the straight bill, the flat back, and stiff tail of the Woodpecker, hesitate to identify the family form in any of the numerous Genera into which this group is now divided. The family characters are even more invariable than the generic ones; for there are Woodpeckers which, instead of the four toes, two turning forward and two backward, which form an essential generic character, have three toes only, while the family form is always maintained, whatever variations there may be in the characters of the more limited groups it includes.

The Turtles and Terrapins form another good illustration of family characters. They constitute together a natural Order, but are distinguished from each other as two Families very distinct in general form and outline. Among Fishes I may mention the Family of Pickerels, with their flat, long snout, and slender, almost cylindrical body, as contrasted with the plump, compressed body and tapering tail of the Trout Family. Or compare, among Insects, the Hawk-Moths with the Diurnal Butterfly, or with the so-called Miller,—or, among Crustacea, the common Crab with the Sea-Spider, or the Lobsters with the Shrimps,—or, among Worms, the Leeches with the Earth-Worms,—or, among Mollusks, the Squids with the Cuttle-Fishes, or the Snails with the Slugs, or the Periwinkles with the Limpets and Conchs, or the Clam with the so-called Venus, or the Oyster with the Mother-of-Pearl shell,—everywhere, throughout the Animal Kingdom, difference of form points at difference of Families.

There is a chapter in the Natural History of Animals that has hardly been touched upon as yet, and that will be especially interesting with reference to Families. The voices of animals have a family character not to be mistaken. All the Canidae bark and howl: the Fox, the Wolf, the Dog have the same kind of utterance, though on a somewhat different pitch. All the Bears growl, from the White Bear of the Arctic snows to the small Black Bear of the Andes. All the Cats miau, from our quiet fireside companion to the Lions and Tigers and Panthers of the forest and jungle. This last may seem a strange assertion; but to any one who has listened critically to their sounds and analyzed their voices, the roar of the Lion is but a gigantic miau, bearing about the same proportion to that of a Cat as its stately and majestic form does to the smaller, softer, more peaceful aspect of the Cat. Yet, notwithstanding the difference in their size, who can look at the Lion, whether in his more sleepy mood as he lies curled up in the corner of his cage, or in his fiercer moments of hunger or of rage, without being reminded of a Cat? And this is not merely the resemblance of one carnivorous animal to another; for no one was ever reminded of a Dog or Wolf by a Lion. Again, all the Horses and Donkeys neigh; for the bray of the Donkey is only a harsher neigh, pitched on a different key, it is true, but a sound of the same character,—as the Donkey himself is but a clumsy and dwarfish Horse. All the Cows low, from the Buffalo roaming the prairie, the Musk-Ox of the Arctic ice-fields, or the Jack of Asia, to the Cattle feeding in our pastures. Among the Birds, this similarity of voice in Families is still more marked. We need only recall the harsh and noisy Parrots, so similar in their peculiar utterance. Or take as an example the web-footed Family,—do not all the Geese and the innumerable host of Ducks quack? Does not every member of the Crow Family caw, whether it be the Jackdaw, the Jay, the Magpie, the Rook in some green rookery of the Old World, or the Crow of our woods, with its long, melancholy caw that seems to make the silence and solitude deeper? Compare all the sweet warblers of the Songster Family,—the Nightingales, the Thrushes, the Mocking-Birds, the Robins; they differ in the greater or less perfection of their note, but the same kind of voice runs through the whole group. These affinities of the vocal systems among animals form a subject well worthy of the deepest study, not only as another character by which to classify the Animal Kingdom correctly, but as bearing indirectly also on the question of the origin of animals. Can we suppose that characteristics like these have been communicated from one animal to another? When we find that all the members of one zoological Family, however widely scattered over the surface of the earth, inhabiting different continents and even different hemispheres, speak with one voice, must we not believe that they have originated in the places where they now occur with all their distinctive peculiarities? Who taught the American Thrush to sing like his European relative? He surely did not learn it from his cousin over the waters. Those who would have us believe that all animals have originated from common centres and single pairs, and have been distributed from such common centres over the world, will find it difficult to explain the tenacity of such characters and their recurrence and repetition under circumstances that seem to preclude the possibility of any communication, on any other supposition than that of their creation in the different regions where they are now found. We have much yet to learn in this kind of investigation, with reference not only to Families among animals, but to nationalities among men also. I trust that the nature of languages will teach us as much about the origin of the races as the vocal systems of the animals may one day teach us about the origin of the different groups of animals. At all events, similarity of vocal utterance among animals is not indicative of identity of Species; I doubt, therefore, whether similarity of speech proves community of origin among men.

The similarity of motion in Families is another subject well worth the consideration of the naturalist: the soaring of the Birds of Prey,—the heavy flapping of the wings in the Gallinaceous Birds,—the floating of the Swallows, with their short cuts and angular turns,—the hopping of the Sparrows,—the deliberate walk of the Hens and the strut of the Cocks,—the waddle of the Ducks and Geese,—the slow, heavy creeping of the Land-Turtle,—the graceful flight of the Sea-Turtle under the water,—the leaping and swimming of the Frog,—the swift run of the Lizard, like a flash of green or red light in the sunshine,—the lateral undulation of the Serpent,—the dart of the Pickerel,—the leap of the Trout,—the rush of the Hawk-Moth through the air,—the fluttering flight of the Butterfly,—the quivering poise of the Humming-Bird,—the arrow-like shooting of the Squid through the water, —the slow crawling of the Snail on the land,—the sideway movement of the Sand-Crab,—the backward walk of the Crawfish,—the almost imperceptible gliding of the Sea-Anemone over the rock,—the graceful, rapid motion of the Pleurobrachia, with its endless change of curve and spiral. In short, every Family of animals has its characteristic action and its peculiar voice; and yet so little is this endless variety of rhythm and cadence both of motion and sound in the organic world understood, that we lack words to express one-half its richness and beauty.

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