HYPSOMETRIC ADDENDA.

I am indebted to Mr. Pentland, whose scientific labours have thrown so much light on the geology and geography of Bolivia, for the following determinations of position, which he communicated to me in a letter from Paris (October 1848), subsequent to the publication of his great map.

Nevado of Sorata, or Ancohuma.South Latitude.Longitude.Height.
South Peak15° 51′ 33″68° 33′ 55″21,286
North Peak15° 49′ 18″68° 33′ 52″21,043
Illimani.
South Peak16° 38′ 52″67° 49′ 18″21,145
Middle Peak16° 38′ 26″67° 49′ 17″21,094
North Peak16° 37′ 50″67° 49′ 39″21,060

The numbers representing the heights are, with the exception of the unimportant difference of a few feet in the South Peak of Illimani, the same as those in the map of the Lake of Titicaca. A sketch of the Illimani, as it appears in all its majesty from La Paz, was given at an earlier date by Mr. Pentland in the Journal of the Royal Geographical Society.[[IO]] But this was five years after the publication of the first measurements in the Annuaire du Bureau des Longitudes for 1830, p. 323, which results I myself hastened to disseminate in Germany.[[IP]] The Nevado de Sorata lies to the east of the village of Sorata or Esquibel, and is called in the Ymarra language, according to Pentland, Ancomani, Itampu, and Illhampu. In Illimani we recognize the Ymarra word illi, snow.

If, however, in the eastern chain of Bolivia the Sorata was long assumed to be 3962 feet, and the Illimani 2851 feet too high, there are in the western chain of Bolivia, according to Pentland’s map of Titicaca (1848), four peaks east of Arica between the latitudes 18° 7′ and 18° 25′, all of which exceed Chimborazo in height, which itself is 21,422 feet.

These four peaks are:—

English feet.French feet.
Pomarape21,70020,360
Gualateiri21,96020,604
Parinacota22,03020,670
Sahama22,35020,971

Berghaus has applied to the chains of the Andes in Bolivia, the investigation which I published[[IQ]] regarding the proportion, which varies extremely in different mountain-chains, of the mountain ridge (the mean height of the passes), to the highest summits (or the culminating points). He finds,[[IR]] according to Pentland’s map, that the mean height of the passes in the eastern chain is 13,505, and in the western chain 14,496 feet. The culminating points are 21,285 and 22,350 feet; consequently the ratio of the height of the ridge to that of the highest summit is, in the eastern chain, as 1 : 1·57, and in the western chain as 1 : 1·54. This ratio, which is, as it were, the measure of the subterranean upheaving force, is very similar to that in the Pyrenees, but very different from the plastic form of the Alps, the mean height of whose passes is far less in comparison with the height of Mont Blanc. In the Pyrenees these ratios are as 1 : 1·43, and in the Alps as 1 : 2·09.

But, according to Fitzroy and Darwin, the height of the Sahama is still surpassed by 848 feet by that of the volcano Aconcagua (south lat. 32° 39′), in the north-east of Valparaiso in Chili. The officers of the expedition of the Adventure and Beagle found, in August 1835, that the Aconcagua was between 23,000 and 23,400 feet in height. If we reckon it at 23,200 feet it is 1776 feet, higher than Chimborazo.[[IS]] According to more recent calculations,[[IT]] Aconcagua is determined to be 23,906 feet.

Our knowledge regarding the systems of mountains, which, north of the parallels of 30° and 31°, are distinguished as the Rocky Mountains and the Sierra Nevada of California, has been vastly augmented during the last few years in the astronomico-geographical, hypsometric, geognostic, and botanical departments, by the excellent works of Charles Frémont,[[IU]] of Dr. Wislizenus,[[IV]] and of Lieutenants Abert and Peck.[[IW]] There prevails throughout these North American works a scientific spirit deserving of the warmest acknowledgment. The remarkable plateau, referred to in p. 34, between the Rocky Mountains and the Sierra Nevada of California, which rises uninterruptedly from 4000 to 5000 French (4260 to 5330 English) feet high, and is termed the Great Basin, presents an interior closed river-system, thermal springs, and salt lakes. None of its rivers, Bear River, Carson River, and Humboldt River, find a passage to the sea. That which, by a process of induction and combination, I represented in my great map of Mexico, executed in 1804, as the Lake of Timpanogos, is the Great Salt Lake of Frémont’s map. It is 60 miles long from north to south, and 40 miles broad, and it communicates with the fresh-water Lake of Utah, which lies at a higher level, and into which the Timpanogos or Timpanaozu River enters from the eastward, in lat. 40° 13′. The fact of the Lake of Timpanogos not having been placed in my map sufficiently to the north and west, arose from the entire absence, at that period, of all astronomical determinations of position of Santa Fé in New Mexico. For the western margin of the lake the error amounts to almost fifty minutes, a difference of absolute longitude which will appear less striking when it is remembered that my itinerary map of Guanaxuato could only be based for an extent of 15° of latitude on determinations made by the compass (magnetic surveys), instituted by Don Pedro de Rivera.[[IX]] These determinations gave my talented and prematurely lost fellow-labourer, Herr Friesen, 105° 36′ as the longitude of Santa Fé, while, by other combinations, I calculated it at 104° 51′. According to actual astronomical determinations the true longitude appears to be 106°. The relative position of the strata of rock salt found in thick strata of red clay, south-east of the Great Salt Lake (Laguna de Timpanogos), with its many islands, and near the present Fort Mormon and the Utah Lake, is accurately given in my large map of Mexico. I may refer to the most recent evidence of the traveller who made the first trustworthy determinations of position in this region. “The mineral or rock salt, of which a specimen is placed in Congress Library, was found in the place marked by Humboldt in his map of New Spain (northern half), as derived from the journal of the Missionary Father Escalante, who attempted (1777) to penetrate the unknown country from Santa Fé of New Mexico to Monterey of the Pacific Ocean. South-east of the Lake Timpanogos is the chain of the Wha-satch Mountains; and in this, at the place where Humboldt has written Montagnes de sel gemme, this mineral is found.”[[IY]]

A great historical interest is attached to this part of the highland, especially to the neighbourhood of the Lake of Timpanogos, which is probably identical with the Lake of Teguayo, the ancestral seat of the Aztecs. This people, in their migration from Aztlan to Tula, and to the valley of Tenochtitlan in Mexico, made three stations at which the ruins of Casas grandes are still to be seen. The first halting-place of the Aztecs was at the Lake of Teguayo, south of Quivira, the second on the Rio Gila, and the third not far from the Presidio de Llanos. Lieutenant Abert found on the banks of the Rio Gila the same immense quantity of elegantly painted fragments of delf and pottery scattered over a large surface of country, which, at the same place, had excited so much astonishment in the missionaries Francisco Garces and Pedro Fonte. From these products of the hand of man, it may be inferred that there was a time when a higher human civilization existed in this now desolate region. Repetitions of the singular architectural style of the Aztecs, and of their houses of seven stories, are at the present time to be found far to the east of the Rio Grande del Norte; as, for instance, at Taos.[[IZ]] The Sierra Nevada of California is parallel to the coast of the Pacific; but between the latitudes of 34° and 41°, between San Buenaventura and the Bay of Trinidad, there runs, west of the Sierra Nevada, a small coast chain whose culminating point, Monte del Diablo, is 3674 feet high. In the narrow valley, between this coast chain and the great Sierra Nevada, flow from the south the Rio de San Joaquin, and from the north the Rio del Sacramento. It is in the alluvial soil on the banks of the latter river that the rich goldwashings occur, which are now proceeding with so much activity.

Besides the hypsometric levelling and the barometric measurements to which I have already referred (see page 33), between the mouth of the Kanzas River in the Missouri and the coast of the Pacific, throughout the immense expanse of 28° of longitude, Dr. Wislizenus has successfully prosecuted the levelling commenced by myself in the equinoctial zone of Mexico, to the north as far as to lat. 35° 38′, and consequently to Santa Fé del Nuevo Mexico. We learn with astonishment that the plateau which forms the broad crest of the Mexican Andes by no means sinks down to an inconsiderable height, as was long supposed to be the case. I give here, for the first time, according to recent measurements, the line of levelling from the city of Mexico to Santa Fé, which is within 16 miles from the Rio del Norte.

French feet.English feet.
Mexico70087469Ht.
Tula63186733Ht.
San Juan del Rio60906490Ht.
Queretaro59706362Ht.
Celaya56466017Ht.
Salamanca54965761Ht.
Guanaxuato64146836Ht.
Silao55465911Br.
Villa de Leon57556133Br.
Lagos59836376Br.
Aguas Calientes58756261Br.
San Luis Potosi57146090Br.
Zacatecas75448038Br.
Fresnillo67977244Br.
Durango64266848(Oteiza)
Parras46784985Ws.
Saltillo49175240Ws.
El Bolson de Mapimifrom 36003836Ws.
to 42004476
Chihuahua43524638Ws.
Cosiquiriachi58866273Ws.
Passo del Norte (on the Rio Grande del Norte)35773810Ws.
Santa Fé del Nuevo Mexico66127047Ws.

The attached letters Ws., Br., and Ht., indicate the barometric measurements of Dr. Wislizenus, Obergrath Burkart, and myself. To the valuable memoir of Dr. Wislizenus there are appended three profile delineations of the country; one from Santa Fé to Chihuahua over Passo del Norte; one from Chihuahua over Parras to Reynosa; and one from Fort Independence (a little to the east of the confluence of the Missouri and the Kanzas River) to Santa Fé. The calculation is based on daily corresponding observations of the barometer, made by Engelmann at St. Louis, and by Lilly in New Orleans. If we consider that in the north and south direction the difference of latitude between Santa Fé and Mexico is more than 16°, and that, consequently, the distance in a direct meridian direction, independently of curvatures on the road, is more than 960 miles; we are led to ask whether, in the whole world, there exists any similar formation of equal extent and height (between 5000 and 7500 feet above the level of the sea). Four-wheeled waggons can travel from Mexico to Santa Fé. The plateau, whose levelling I have here described, is formed solely by the broad, undulating, flattened crest of the chain of the Mexican Andes; it is not the swelling of a valley between two mountain-chains, such as the “Great Basin” between the Rocky Mountains and the Sierra Nevada of California, in the Northern Hemisphere, or the elevated plateau of the Lake of Titicaca, between the eastern and western chains of Bolivia, or the plateau of Thibet, between the Himalaya and the Kuen-lün, in the Southern Hemisphere.

IDEAS
FOR A
PHYSIOGNOMY OF PLANTS.

When the active spirit of man is directed to the investigation of nature, or when in imagination he scans the vast fields of organic creation, among the varied emotions excited in his mind there is none more profound or vivid than that awakened by the universal profusion of life. Everywhere—even near the ice-bound poles,—the air resounds with the song of birds and with the busy hum of insects. Not only the lower strata, in which the denser vapours float, but also the higher and ethereal regions of the air, teem with animal life. Whenever the lofty crests of, the Peruvian Cordilleras, or the summit of Mont Blanc, south of Lake Leman, have been ascended, living creatures have been found even in these solitudes. On the Chimborazo[[71]], which is upwards of eight thousand feet higher than Mount Etna, we saw butterflies and other winged insects. Even if they are strangers carried by ascending currents of air to those lofty regions, whither a restless spirit of inquiry leads the toilsome steps of man, their presence nevertheless proves that the more pliant organization of animals may subsist far beyond the limits of the vegetable world. The Condor[[72]], that giant among the vultures, often soared above us at a greater altitude than the summits of the Andes, and even higher than would be the Peak of Teneriffe were it piled upon the snow-crowned summits of the Pyrenees. Rapacity and the pursuit of the soft-woolled Vicunas, which herd, like the chamois, on the snow-covered pastures, allure this powerful bird to these regions.

But if the unassisted eye shows that life is diffused throughout the whole atmosphere, the microscope reveals yet greater wonders. Wheel-animalcules, brachioni, and a host of microscopic insects are lifted by the winds from the evaporating waters below. Motionless and to all appearance dead, they float on the breeze, until the dew bears them back to the nourishing earth, and bursting the tissue which incloses their transparent rotating[[73]] bodies, instils new life and motion into all their organs, probably by the action of the vital principle inherent in water. The yellow meteoric sand or mist (dust nebulæ) often observed to fall on the Atlantic near the Cape de Verde Islands, and not unfrequently borne in an easterly direction as far as Northern Africa, Italy, and Central Europe, consists, according to Ehrenberg’s brilliant discovery, of agglomerations of siliceous-shelled microscopic organisms. Many of these perhaps float for years in the highest strata of the atmosphere, until they are carried down by the Etesian winds or by descending currents of air, in the full capacity of life, and actually engaged in organic increase by spontaneous self division.

Together with these developed creatures, the atmosphere contains countless germs of future formations; eggs of insects, and seeds of plants, which, by means of hairy or feathery crowns, are borne forward on their long autumnal journey. Even the vivifying pollen scattered abroad by the male blossoms, is carried by winds and winged insects over sea and land, to the distant and solitary female plant[[74]]. Thus, wheresoever the naturalist turns his eye, life or the germ of life lies spread before him.

But if the moving sea of air in which we are immersed, and above whose surface we are unable to raise ourselves, yields to many organic beings their most essential nourishment, they still require therewith a more substantial species of food, which is provided for them only at the bottom of this gaseous ocean. This bottom is of a twofold kind: the smaller portion constituting the dry earth, in immediate contact with the surrounding atmosphere; the larger portion consisting of water,—formed, perhaps, thousands of years ago from gaseous matters fused by electric fire, and now incessantly undergoing decomposition in the laboratory of the clouds and in the pulsating vessels of animals and plants. Organic forms descend deep into the womb of the earth, wherever the meteoric rain-waters can penetrate into natural cavities, or into artificial excavations and mines. The domain of the subterranean cryptogamic flora was early an object of my scientific researches. Thermal springs of the highest temperature nourish small Hydropores, Confervæ and Oscillatoræ. Not far from the Arctic circle, at Bear Lake, in the New Continent, Richardson saw flowering plants on the ground which, even in summer, remains frozen to the depth of twenty inches.

It is still undetermined where life is most abundant: whether on the earth or in the fathomless depths of the ocean. Ehrenberg’s admirable work on the relative condition of animalcular life in the tropical ocean and the floating and solid ice of the Antarctic circle, has spread the sphere and horizon of organic life before our eyes. Siliceous-shelled Polygastrica and even Coscinodiscæ, alive, with their green ovaries, have been found enveloped in masses within twelve degrees of the Pole; even as the small black glacier flea, Desoria Glacialis, and Podurellæ, inhabit the narrow tubules of ice of the Swiss glaciers, as proved by the researches of Agassiz. Ehrenberg has shown that on some microscopic infusorial animalcules (Synedra and Cocconeis), other species live parasitically; and that in the Gallionellæ the extraordinary powers of division and development of bulk are so great, that an animalcule invisible to the naked eye can in four days form two cubic feet of the Bilin polishing slate.

In the ocean, gelatinous sea-worms, living and dead, shine like luminous stars[[75]], converting by their phosphorescent light the green surface of the ocean into one vast sheet of fire. Indelible is the impression left on my mind by those calm tropical nights of the Pacific, where the constellation of Argo in its zenith, and the setting Southern Cross, pour their mild planetary light through the ethereal azure of the sky, while dolphins mark the foaming waves with their luminous furrows.

But not alone the depths of ocean, the waters, too, of our own swamps and marshes, conceal innumerable worms of wonderful form. Almost indistinguishable by the eye are the Cyclidiæ, the Euglenes, and the host of Naiads divisible by branches like the Lemna (Duckweed), whose leafy shade they seek. Surrounded by differently composed atmospheres, and deprived of light, the spotted Ascaris breathes in the skin of the earth-worm, the silvery and bright Leucophra exists in the body of the shore Nais, and a Pentastoma in the large pulmonary cells of the tropical rattle-snake[[76]]. There are animalcules in the blood of frogs and salmon, and even, according to Nordmann, in the fluid of the eyes of fishes, and in the gills of the bream. Thus are even the most hidden recesses of creation replete with life. We purpose in the following pages to consider the different families of plants, since on their existence entirely depends that of the animal creation. Incessantly are they occupied in organizing the raw material of the earth, assimilating by vital forces those elements which after a thousand metamorphoses become ennobled into active nervous tissue. The glance which we direct to the dissemination of vegetable forms, reveals to us the fulness of that animal life which they sustain and preserve.

The verdant carpet which a luxuriant Flora spreads over the surface of the earth is not woven equally in all parts; for while it is most rich and full where, under an ever-cloudless sky, the sun attains its greatest height, it is thin and scanty near the torpid poles, where the quickly-recurring frosts too speedily blight the opening bud or destroy the ripening fruit. Yet everywhere man rejoices in the presence of nourishing plants. Even where from the depths of the sea, a volcano bursting through the boiling flood, upheaves a scoriaceous rock. (as once happened in the Greek Islands); or, to instance a more gradual phenomenon, where the united labours of the coral animal (Lithophytes)[[77]] have piled up their cellular dwellings, on the crests of submarine mountains, until after toiling for thousands of years their edifice reaches the level of the ocean, when its architects perish, and leave a coral island. Thus are organic forces ever ready to animate with living forms the naked rock. How seeds are so suddenly transported to these rocks, whether by birds, or by winds, or by the waves of ocean, is a question that cannot be decided, owing to the great distance of these islands from the coasts. But no sooner has the air greeted the naked rock, than, in our northern countries, it gradually acquires a covering of velvet-like fibres, which appear to the eye to be coloured spots. Some of these are bordered by single and others by double rows, while others again are traversed by furrows and divided into compartments. As they increase in age their colour darkens. The bright glittering yellow becomes brown, and gradually the bluish-grey mass of the Leprariæ changes to a dusty black. As the outlines of this vegetable surface merge into each other with increasing age, the dark ground acquires a new covering of fresh circular spots of dazzling whiteness. Thus one organic tissue rises, like strata, over the other; and as the human race in its development must pass through definite stages of civilization, so also is the gradual distribution of plants dependent on definite physical laws. In spots where lofty forest trees now rear their towering summits, the sole covering of the barren rock was once the tender lichen; the long and immeasurable interval was filled up by the growth of grasses, herbaceous plants, and shrubs. The place occupied in northern regions by mosses and lichens is supplied in the tropics by Portulacas, Gomphrenas, and other low and oleaginous marine plants. The history of the vegetable covering and of its gradual extension over the barren surface of the earth, has its epochs, as well as that of the migratory animal world.

But although life is everywhere diffused, and although the organic forces are incessantly at work in combining into new forms those elements which have been liberated by death; yet this fulness of life and its renovation differ according to difference of climate. Nature undergoes a periodic stagnation in the frigid zones; for fluidity is essential to life. Animals and plants, excepting indeed mosses and other Cryptogamia, here remain many months buried in a winter sleep. Over a great portion of the earth, therefore, only those organic forms are capable of full development, which have the property of resisting any considerable abstraction of heat, or those which, destitute of leaf-organs, can sustain a protracted interruption of their vital functions. Thus, the nearer we approach the tropics, the greater the increase in variety of structure, grace of form, and mixture of colours, as also in perpetual youth and vigour of organic life.

This increase may readily be doubted by those who have never quitted our own hemisphere, or who have neglected the study of physical geography. When in passing from our thickly foliated forests of oak, we cross the Alps or the Pyrenees and enter Italy or Spain, or when the traveller first directs his eye to some of the African coasts of the Mediterranean, he may easily be led to adopt the erroneous inference that absence of trees is a characteristic of hot climates. But they forget that Southern Europe wore a different aspect, when it was first colonised by Pelasgian or Carthaginian settlers; they forget too that an earlier civilization of the human race sets bounds to the increase of forests, and that nations, in their change-loving spirit, gradually destroy the decorations which rejoice our eye in the North, and which, more than the records of history, attest the youthfulness of our civilization. The great catastrophe by which the Mediterranean was formed, when the swollen waters of an inland sea burst their way through the Dardanelles and the Pillars of Hercules, appears to have stripped the contiguous lands of a large portion of their alluvial soil. The records of the Samothracian traditions[[78]] preserved by Greek writers seem to indicate the recent date of this great convulsion of nature. Moreover, in all the lands bathed by the Mediterranean, and which are characterised by the tertiary and cretaceous formations (Nummulites and Neocomian rocks), a great portion of the earth’s surface is naked rock. The picturesque beauty of Italian scenery depends mainly on the pleasing contrast between the bare and desolate rock and the luxuriant vegetation which, island-like, is scattered over its surface. Where the rock is less intersected by fissures, so that the water rests longer on its surface, and where it is covered with earth (as on the enchanting banks of Lake Albano), there even Italy has her oak-forests, as shady and verdant as could be desired by an inhabitant of the North.

The boundless plains or steppes of South America, and the deserts beyond the Atlas range of mountains, can only be regarded as mere local phenomena. The former are found to be covered, at least in the rainy season, with grasses and low almost herbaceous Mimosæ; while the latter are seas of sand in the interior of the Old Continent,—vast arid tracts surrounded by borders of evergreen forests. Here and there only a few isolated fan-palms remind the wanderer that these dreary solitudes are a portion of animated nature. Amid the optical delusions occasioned by the radiation of heat, we see the bases of these trees at one moment hovering in the air, at the next their inverted image reflected in the undulating strata of the atmosphere. To the west of the Peruvian Andes, on the shores of the Pacific, I have passed weeks in traversing these waterless deserts.

The origin of this absence of plants over large tracts of land, in regions characterised on every side by the most exuberant vegetation, is a geological phenomenon which has hitherto received but little attention; it undoubtedly arises from former revolutions of nature, such as inundations, or from volcanic convulsions of the earth’s surface. When once a region loses its vegetable covering, if the sand is loose and devoid of springs, and if vertically ascending currents of heated air prevent the precipitation of vapour[[79]], thousands of years may elapse before organic life can penetrate from the green shores to the interior of the dreary waste.

Those who are capable of surveying nature with a comprehensive glance, and abstract their attention from local phenomena, cannot fail to observe that organic development and abundance of vitality gradually increase from the poles towards the equator, in proportion to the increase of animating heat. But in this distribution every different climate has allotted to it some beauty peculiar to itself: to the Tropics belong variety and magnitude in vegetable forms; to the North the aspect of its meadows and the periodical renovation of nature at the first genial breath of spring. Every zone, besides its own peculiar advantages, has its own distinctive character. The primeval force of organization, notwithstanding a certain independence in the abnormal development of individual parts, binds all animal and vegetable structures to fixed ever-recurring types. For as in some individual organic beings we recognise a definite physiognomy, and as descriptive botany and zoology are, strictly speaking, analyses of animal and vegetable forms, so also there is a certain natural physiognomy peculiar to every region of the earth.

That which the painter designates by the expressions “Swiss scenery” or “Italian sky” is based on a vague feeling of the local natural character. The azure of the sky, the effects of light and shade, the haze floating on the distant horizon, the forms of animals, the succulence of plants, the bright glossy surface of the leaves, the outlines of mountains, all combine to produce the elements on which depends the impression of any one region. It must be admitted, however, that in all latitudes the same kind of rocks, as trachyte, basalt, porphyritic schist, and dolomite, form mountain groups of exactly similar physiognomy. Thus the greenstone cliffs of South America and Mexico resemble those of the Fichtel mountains of Germany, in like manner as among animals, the form of the Allco, or the original canine race of the New Continent, is analogous to that of the European race. The inorganic crust of the earth is as it were independent of climatic influences; perhaps, because diversity of climate arising from difference of latitude is of more recent date than the formations of the earth, or that the hardening crust, in solidifying and discharging its caloric, acquired its temperature from internal and not from external causes[[80]]. All formations are, therefore, common to every quarter of the globe and assume the like forms. Everywhere basalt rises in twin mountains and truncated cones; everywhere trap-porphyry presents itself to the eye under the form of grotesquely-shaped masses of rock, while granite terminates in gently rounded summits. Thus, too, similar vegetable forms, as pines and oaks, alike crown the mountain declivities of Sweden and those of the most southern portion of Mexico[[81]]. But notwithstanding all this coincidence of form, and resemblance of the outlines of individual portions, the grouping of the mass, as a whole, presents the greatest diversity of character.

As the oryctognostic knowledge of minerals differs from geology, so also does the general study of the physiognomy of nature differ from the individual branches of the natural sciences. The character of certain portions of the earth’s surface has been described with inimitable truthfulness by George Forster in his travels and smaller works, by Goethe in the descriptive passages which so frequently occur in his immortal writings, by Buffon, Bernardin de St. Pierre, and Chateaubriand. Such descriptions are not only calculated to yield an enjoyment of the noblest kind, but the knowledge of the character of nature in different regions is also most intimately associated with the history of the human race and its mental culture. For although the dawn of this culture cannot have been determined solely by physical influence, climatic relations have at any rate to a great extent influenced its direction, as well as the character of nations, and the degree of gloom or cheerfulness in the dispositions of men. How powerfully did the skies of Greece act on its inhabitants! Was it not among the nations who settled in the beautiful and happy region between the Euphrates, the Halys, and the Ægean Sea, that social polish and gentler feelings were first awakened? and was it not from these genial climes that our forefathers, when religious enthusiasm had suddenly opened to them the Holy Lands of the East, brought back to Europe, then relapsing into barbarism, the seeds of a gentler civilization? The poetical works of the Greeks and the ruder songs of the primitive northern races owe much of their peculiar character to the forms of plants and animals, to the mountain-valleys in which their poets dwelt, and to the air which surrounded them. To revert to more familiar objects, who is there that does not feel himself differently affected beneath the embowering shade of the beechen grove, or on hills crowned with a few scattered pines, or in the flowering meadow where the breeze murmurs through the trembling foliage of the birch? A feeling of melancholy, or solemnity, or of light buoyant animation is in turn awakened by the contemplation of our native trees. This influence of the physical on the moral world—this mysterious reaction of the sensuous on the ideal, gives to the study of nature, when considered from a higher point of view, a peculiar charm which has not hitherto been sufficiently recognised.

However much the character of different regions of the earth may depend upon a combination of all these external phenomena, and however much the total impression may be influenced by the outline of mountains and hills, the physiognomy of plants and animals, the azure of the sky, the form of the clouds, and the transparency of the atmosphere, still it cannot be denied that it is the vegetable covering of the earth’s surface which chiefly conduces to the effect. The animal organism is deficient in mass, while the mobility of its individual members and often their diminutiveness remove them from the sphere of our observation. Vegetable forms, on the other hand, act on the imagination by their enduring magnitude—for here massive size is indicative of age, and in the vegetable kingdom alone are age and the manifestation of an ever-renewed vigour linked together. The colossal Dragon Tree[[82]], which I saw in the Canary Isles, and which measured more than sixteen feet in diameter, still bears, as it then did, the blossoms and fruit of perpetual youth. When the French adventurers, the Béthencourts, conquered these Fortunate Isles in the beginning of the fifteenth century, the Dragon Tree of Orotava, regarded by the natives with a veneration equal to that bestowed on the olive tree of the Acropolis at Athens, or the elm at Ephesus, was of the same colossal magnitude as at present. In the tropics a grove of Hymeneæ and Cesalpiniæ is probably a memorial of more than a thousand years.

On taking one general view of the different phanerogamic species which have already been collected into our herbariums[[83]], and which may now be estimated at considerably more than 80,000, we find that this prodigious quantity presents some few forms to which most of the others may be referred. In determining those forms, on whose individual beauty, distribution, and grouping, the physiognomy of a country’s vegetation depends, we must not ground our opinion (as from other causes is necessarily the case in botanical systems) on the smaller organs of propagation, that is, the blossoms and fruit; but must be guided solely by those elements of magnitude and mass from which the total impression of a district receives its character of individuality. Among the principal forms of vegetation there are, indeed, some which constitute entire families, according to the so-called “natural system” of botanists. Bananas and Palms, Casuarineæ and Coniferæ, form distinct species in this mode of arrangement. The systematising botanist, however, separates into different groups many plants which the student of the physiognomy of nature is compelled to associate together. Where vegetable forms occur in large masses, the outlines and distribution of the leaves, and the form of the stems and branches lose their individuality and become blended together. The painter—and here his delicate artistical appreciation of nature comes especially into play—distinguishes between pines or palms and beeches in the background of a landscape, but not between forests of beech and other thickly foliated trees.

The physiognomy of nature is principally determined by sixteen forms of plants. I merely enumerate such as I have observed in my travels through the old and new world during many years’ study of the vegetation of different latitudes, between the parallels of 60° north and 12° south. The number of these forms will no doubt be considerably increased by travellers penetrating further into the interior of continents, and discovering new genera of plants. We are still wholly ignorant of the vegetation of the south-east of Asia, the interior of Africa and New Holland, and of South America from the Amazon to the province of Chiquitos. Might not a region be some day discovered in which ligneous fungi, Cenomyce rangiferina, or mosses, form high trees? Neckera dendroïdes, a German species of moss, is in fact arborescent, and the sight of a wood of lofty mosses could hardly afford greater astonishment to its discoverers than that experienced by Europeans at the aspect of arborescent grasses (bamboos) and the tree-ferns of the tropics, which are often equal in height to our lindens and alders. The maximum size and degree of development attainable by organic forms of any genus, whether of animals or plants, are determined by laws with which we are still unacquainted. In each of the great divisions of the animal kingdom, as insects, reptiles, crustacea, birds, fishes, or mammalia, the dimensions of the body oscillate between certain extreme limits. But these limits, based on the observations hitherto contributed to science, may be enlarged by new discoveries of species with which we are at present unacquainted.

In land animals a high degree of temperature, depending on latitude, appears to have exercised a favourable influence on the genetic development of organization. Thus the small and slender form of our lizards expands in the south into the colossal, unwieldy, and mail-clad body of the formidable crocodile. In the huge cats of Africa and America, the tiger, lion, and jaguar, we find, repeated on a larger scale, the form of one of the smallest of our domestic animals. But if we penetrate into the recesses of the earth, and search the tombs of plants and animals, the fossil remains thus brought to light not only manifest a distribution of forms at variance with the present climates, but they also reveal colossal structures, which exhibit as marked a contrast with the small types that now surround us, as does the simple yet dignified heroism of the ancient Greeks, when compared with what is recognized at the present day as “greatness of character.” If the temperature of the earth has undergone considerable, perhaps periodically recurring changes, and, if even the relations between sea and land, and the height and pressure of the atmospheric ocean[[84]], have not always been the same, then the physiognomy of nature, and the magnitude and forms of organic bodies, must also have been subject to many variations. Enormous Pachydermata, elephantine Mastodons, Owen’s Mylodon robustus, and the Colossochelys,[[JA]] a land tortoise upwards of six feet in height, once inhabited forests of colossal Lepidodendra, cactus-like Stigmariæ, and numerous genera of Cycadeæ. Unable accurately to delineate the physiognomy of our aging and altering planet according to its present features, I will only attempt to bring prominently forward those characteristics which specially appertain to each individual group of plants. Notwithstanding all the richness and adaptability of our language, the attempt to designate in words, that which, in fact, appertains only to the imitative art of the painter, is always fraught with difficulty. I would also wish to avoid that wearying effect which is almost unavoidably inseparable from a long enumeration of individual forms.

We will begin with Palms[[85]], the loftiest and most stately of all vegetable forms. To these, above all other trees, the prize of beauty has always been awarded by every nation; and it was from the Asiatic palm-world, or the adjacent countries, that human civilization sent forth the first rays of its early dawn. Marked with rings, and not unfrequently armed with thorns, the tall and slender shaft of this graceful tree rears on high its crown of shining, fan-like, or pinnated leaves, which are often curled like those of some gramineæ. Smooth stems of the palm, which I carefully measured, rose to a height of 190 feet. The palm diminishes in size and beauty as it recedes from the equatorial towards the temperate zones. Europe owns amongst its indigenous trees only one representative of this form of vegetation, the dwarfish coast palm (Chamæops), which, in Spain and Italy, is found as far north as 44° lat. The true palm climate has a mean annual temperature of 78° to 81°.5 Fahr., but the date-palm, which has been brought to us from Africa, and is less beautiful than other species of this family, vegetates in the south of Europe in districts whose mean temperature is only from 59° to 62°.4 Fahr. Stems of palms and skeletons of elephants are found buried in the interior of the earth in Northern Europe; their position renders it probable that they were not drifted from the tropics towards the north, but that, in the great revolutions of our planet, climates, and the physiognomy of nature which is regulated by climate, have been, in many respects, altered.

In all regions of the earth the palm is found associated with the plantain or banana; the Scitamineæ and Musaceæ of botanists, Heliconia, Amomum, and Strelitzia. This form has a low, succulent, and almost herbaceous stem, the summit of which is crowned with delicately striped, silky, shining leaves of a thin and loose texture. Groves of bananas form the ornament of humid regions; and on their fruit the natives of the torrid zone chiefly depend for subsistence. Like the farinaceous cereals or corn-yielding plants of the north, the banana has accompanied man from the earliest infancy of his civilization[[86]]. By some Semitic traditions the primitive seat of these nutritious tropical plants has been placed on the shores of the Euphrates, and by others, with greater probability, in India, at the foot of the Himalaya mountains. Greek legends cite the plains of Enna as the home of the cereals. Whilst, however, the cereals, spread by culture over the northern regions, in monotonous and far extending tracts, add but little to the beauty of the landscape; the inhabitant of the tropics, on the other hand, is enabled, by the propagation of the banana, to multiply one of the noblest and most lovely of vegetable productions.

The form of the Malvaceæ[[87]] and Bombaceæ, represented by Ceiba, Cavanillesia, and the Mexican hand tree (Cheirostemon), has immensely thick stems, with lanuginous, large, cordate, or indented leaves, and magnificent flowers, frequently of a purple-red. To this group belongs the Baobab, or monkey bread-tree, Adansonia digitata, which, with a moderate height, has occasionally a diameter of 32 feet,[[JB]] and may probably be regarded as at once the largest and most ancient organic memorial of our planet. The Malvaceæ already begin to impart to the vegetation of Italy a peculiarly southern character.

The temperate zone in our old continent unfortunately is wholly devoid of the delicately pinnate Mimosas[[88]], whose predominating forms are Acacia, Desmanthus, Gleditschia, Porleria, and Tamarindus. This beautiful form occurs in the United States of North America, where, under equal parallels of latitude, vegetation is more varied and luxuriant than in Europe. The Mimosas are generally characterised, like the Italian pine, by an umbellate expansion of their branches. An extremely picturesque effect is produced by the deep blue of a tropical sky gleaming through the delicate tracery of their foliage.

Heaths[[89]], which more especially belong to an African group of plants, include, according to physiognomic character and general appearance, the Epacrideæ and Diosmeæ, many Proteaceæ, and the Australian Acacias, which have no leaves but mere flattened petioles (phyllodia). This group bears some resemblance to acicular-leaved forms, with which it contrasts the more gracefully by the abundance of its campanulate blossoms. The arborescent heaths, like some few other African plants, extend as far as the northern shores of the Mediterranean. They adorn the plains of Italy, and the Cistus groves of southern Spain, but I have nowhere seen them growing more luxuriantly than on the declivities of the Peak of Teyde at Teneriffe. In the countries bordering on the Baltic, and further northward, the appearance of this form of plants is regarded with apprehension, as the precursor of drought and barrenness. Our heaths, Erica (Calluna) vulgaris, and Erica tetralix, E. carnea and E. cinerea, are social plants, against whose extension agricultural nations have contended for centuries, with but little success. It is singular that the principal representative of this family should be peculiar to one side of our planet alone. There is only one of the three hundred known species of Erica to be met with in the new continent, from Pennsylvania and Labrador to Nootka Sound and Alaschka.

The Cactus form[[90]], on the other hand, is almost peculiar to the new continent; it is sometimes globular, sometimes articulated, sometimes rising in tall polygonal columns not unlike organ-pipes. This group forms the most striking contrast with the Lily and Banana families, and belongs to that class of plants which Bernardin de St. Pierre felicitously terms vegetable fountains of the Desert. In the parched arid plains of South America, the thirsting animals eagerly seek the Melon-cactus, a globular plant half-buried in the dry sand, whose succulent interior is concealed by formidable prickles. The stems of the columnar cactus attain a height of more than 30 feet; their candelabra-like ramifications, frequently covered with lichens, reminding the traveller, by some analogy in their physiognomy, of certain of the African Euphorbias.

While these plants form green Oases in the barren desert, the Orchideæ[[91]] shed beauty over the most desolate rocky clefts, and the seared and blackened stems of those tropical trees which have been discoloured by the action of light. The Vanilla form is distinguished by its light green succulent leaves, and by its variegated and singularly shaped blossoms. Some of the orchideous flowers resemble in shape winged insects, while others look like birds, attracted by the fragrance of the honey vessels. An entire life would not suffice to enable an artist, although limiting himself to the specimens afforded by one circumscribed region, to depict the splendid Orchideæ which embellish the deep alpine valleys of the Peruvian Andes.

The form of the Casuarineæ[[92]], leafless, like almost all the species of Cactus, comprises a group of trees having branches resembling the Equisetum, and is peculiar to the islands of the Pacific and to the East Indies. Traces of this type, which is certainly more singular than beautiful, may however be found in other regions of the earth. Plumier’s Equisetum altissimum, Forskäl’s Ephedra aphylla of North Africa, the Peruvian Colletia, and the Siberian Calligonum Pallasia, are nearly allied to the form of the Casuarinas.

While the Banana form presents us with the greatest degree of expansion, the Casuarinas and the acicular-leaved[[93]] trees exhibit the greatest contraction of the leaf-vessels. Pines, Thujas, and Cypresses constitute a northern form but rarely met with in the tropics and in some coniferæ (Dammara Salisburia), the leaves are both broad and acicular. Their evergreen foliage enlivens the gloom of the dreary winter landscape, while it proclaims to the natives of the polar regions that, although snow and ice cover the surface, the inner life of plants, like the Promethean fire, is never wholly extinct on our planet.

Besides the Orchideæ, the Pothos tribe of plants[[94]] also yields a graceful covering to the aged stems of forest trees in the tropical world, like the parasitic mosses and lichens of our own climes. Their succulent herbaceous stalks are furnished with large leaves, arrow-shaped, digitate, or elongated, and invariably furnished with thick veins. The blossoms of the Aroideæ are inclosed in spathes, by which their vital heat is increased; they are stemless, and send forth aërial roots. Pothos, Dracontium, Caladium, and Arum are all kindred forms; and the last-named extends as far as the coasts of the Mediterranean, contributing, together with succulent Tussilago (Coltsfoot), high thistles, and the Acanthus, to give a luxuriant southern character to the vegetation of Spain and Italy.

This Arum form is associated, in the torrid regions of South America, with the tropical Lianes or creeping plants[[95]], which exhibit the utmost luxuriance of vegetation in Paullinias, Banisterias, Bignonias, and Passion-flowers. Our tendrilled hops and vines remind us of this tropical form. On the Orinoco the leafless branches of the Bauhinia are often upwards of 40 feet in length, sometimes hanging perpendicularly from the summit of lofty Swieteniæ, (Mahogany trees), sometimes stretched obliquely like ropes from a mast; along these the tiger-cat may be seen climbing to and fro with wonderful agility.

The self-sustaining form of the bluish-flowered Aloe tribe[[96]] presents a marked contrast to the pliant climbing lianes with their fresh and brilliant verdure. When there is a stem it is almost branchless, closely marked with spiral rings, and surrounded by a crown of succulent, fleshy, long-pointed leaves, which radiate from a centre. The lofty-stemmed aloe does not grow in clusters like other social plants, but stands isolated in the midst of dreary solitudes, imparting to the tropical landscape a peculiar melancholy (one might almost say African) character.

To this aloe form belong, in reference to physiognomic resemblance and the impression they produce on the landscape: the Pitcairnias, from the family of the Bromeliaceæ, which in the chain of the Andes grow out of clefts in the rock; the great Pournetia pyramidata (the Atschupalla of the elevated plateaux of New Grenada); the American aloe (Agave), Bromelia Ananas and B. Karatas; those rare species of the family of the Euphorbiaceæ, which have thick, short, candelabra-like divided stems; the African aloe, and the Dragon tree, Dracæna Draco, of the family of the Asphodeleæ; and lastly the tall flowering Yucca, allied to the Liliaceæ.

While the Aloe form is characterised by an air of solemn repose and immobility, the grass form[[97]], especially as regards the physiognomy of the arborescent grasses, is expressive of buoyant lightness and flexible slenderness. In both the Indies, bamboo groves form arched and shady walks.

The smooth and often inclined and waving stem of the tropical grasses exceeds in height our alders and oaks. As far north as Italy, this form already begins, in the Arundo Donax, to raise itself from the ground, and to determine, by height as well as mass, the natural character of the country.

The form of Ferns[[98]], like that of grasses, also assumes nobler dimensions in the torrid regions of the earth, and the arborescent ferns, which frequently attain the height of above forty feet, have a palm-like appearance, although their stem is thicker, shorter, and more rough and scaly, than that of the palm. The leaf is more delicate, of a loose and more transparent texture, and sharply serrated on the margins. These colossal ferns belong almost exclusively to the tropics, but there they prefer the temperate localities. As in these latitudes diminution of heat is merely the consequence of an increase of elevation, we may regard mountains that rise 2000 or 3000 feet above the level of the sea as the principal seat of these plants. Arborescent ferns grow in South America, side by side with that beneficent tree whose stem yields the febrifuge bark, and both forms of vegetation are indicative of the happy region where reigns the genial mildness of perpetual spring.

I have now to mention the form of the Liliaceous plants[[99]], Amaryllis, Ixia, Gladiolus, and Pancratium, with their flag-like leaves and splendid blossoms, the principal home of which is Southern Africa; also the Willow form[[100]], which is indigenous in all latitudes, and is represented in the plateaux of Quito, not by the shape of its leaves, but in the form of its ramification, in Schinus Molle; also the Myrtle-form[[101]] (Metrosideros, Eucalyptus, Escallonia myrtelloides); Melastomaceæ[[102]]; and the Laurel form[[103]].

It would be an undertaking worthy of a great artist to study the character of all these vegetable groups, not in hothouses, or from the descriptions of botanists, but on the grand theatre of tropical nature. How interesting and instructive to the landscape painter[[104]] would be a work that should present to the eye accurate delineations of the sixteen principal forms enumerated, both individually and in collective contrast! What can be more picturesque than the arborescent Ferns, which spread their tender foliage above the Mexican laureloak! what more charming than the aspect of banana-groves, shaded by those lofty grasses, the Guadua and Bamboo! It is peculiarly the privilege of the artist to separate these into groups, and thus the beautiful images of nature, if we may be permitted the simile, resolve themselves beneath his touch, like the written works of man, into a few simple elements.

It is beneath the glowing rays of a tropical sun, that the noblest forms of vegetation are developed. In the cold North the bark of trees is covered only with dry lichens and mosses, while beneath the tropics the Cymbidium and the fragrant Vanilla adorn the trunks of the Anacardias and the gigantic Fig-tree. The fresh green of the Pothos leaves and of the Dracontias contrast with the many coloured blossoms of the Orchideæ; climbing Bauhinias, Passion-flowers and golden flowered Banisterias encircle every tree of the forest. Delicate blossoms unfold themselves from the roots of the Theobroma, and from the thick and rough bark of the Crescentia and Gustavia[[105]]. Amid this luxuriant abundance of flowers and foliage, amid this exuberance and tangled web of creeping plants, it is often difficult for the naturalist to recognise the stems to which the various leaves and blossoms belong. A single tree, adorned with Paullinias, Bignonias, and Dendrobias, forms a group of plants, which, separated from each other, would cover a considerable space of ground.

In the tropics, plants are more succulent, of a fresher green, and have larger and more glossy leaves, than in the northern regions. Social plants, which give such a character of uniformity to European vegetation, are almost wholly absent in the equatorial zone. Trees, almost twice as high as our oaks, there bloom with flowers as large and splendid as our lilies. On the shady banks of the Magdalena River, in South America, grows a climbing Aristolochia, whose blossoms, measuring four feet in circumference, the Indian children sportively draw on their heads as caps[[106]]. In the South Indian Archipelago, the flower of the Rafflesia is nearly three feet in diameter, and weighs above fourteen pounds.

The extraordinary height to which not only individual mountains but even whole districts rise in tropical regions, and the consequent cold of such elevations, affords the inhabitant of the tropics a singular spectacle. For besides his own palms and bananas, he is surrounded by those vegetable forms which would seem to belong solely to northern latitudes. Cypresses, pines, and oaks, barberry shrubs and alders (nearly allied to our own species) cover the mountain plains of Southern Mexico and the chain of the Andes at the equator. Thus nature has permitted the native of the torrid zone to behold all the vegetable forms of the earth without quitting his own clime, even as are revealed to him the luminous worlds which spangle the firmament from pole to pole[[107]].

These and many other of the enjoyments which nature affords are denied to the nations of the North. Many constellations and many vegetable forms, including more especially the most beautiful productions of the earth (palms, tree-ferns, bananas, arborescent grasses, and delicately feathered mimosas), remain for ever unknown to them; for the puny plants pent up in our hothouses, give but a faint idea of the majestic vegetation of the tropics. But the rich development of our language, the glowing fancy of the poet, and the imitative art of the painter, afford us abundant compensation; and enable the imagination to depict in vivid colours the images of an exotic Nature. In the frigid North, amid barren heaths, the solitary student may appropriate all that has been discovered in the most remote regions of the earth, and thus create within himself a world as free and imperishable as the spirit from which it emanates.