English feet. French feet.
Pomarape 21,700 20,360
Gualateiri 21,960 20,604
Parinacota 22,030 20,670
Sahama 22,350 20,971
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.
Mexico 7008 7469 Ht.
Tula 6318 6733 Ht.
San Juan del Rio 6090 6490 Ht.
Queretaro 5970 6362 Ht.
Celaya 5646 6017 Ht.
Salamanca 5496 5761 Ht.
Guanaxuato 6414 6836 Ht.
Silao 5546 5911 Br.
Villa de Leon 5755 6133 Br.
Lagos 5983 6376 Br.
Aguas Calientes 5875 6261 Br.
San Luis Potosi 5714 6090 Br.
Zacatecas 7544 8038 Br.
Fresnillo 6797 7244 Br.
Durango 6426 6848 (Oteiza)
Parras 4678 4985 Ws.
Saltillo 4917 5240 Ws.
───────────────────────────────────────────────────────────────────────
El Bolson de Mapimi from 3600 3836 Ws.
to 4200 4476
───────────────────────────────────────────────────────────────────────
Chihuahua 4352 4638 Ws.
Cosiquiriachi 5886 6273 Ws.
Passo del Norte (on the Rio Grande 3577 3810 Ws.
del Norte)
Santa Fé del Nuevo Mexico 6612 7047 Ws.
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.