_The Variety of Organization corresponding to the Variety of
Climate._
The organization of plants and animals is in different tribes
formed upon schemes more or less different, but in all cases
adjusted in a general way to the course and action of the elements.
The differences are connected with the different habits and manners
of living which belong to different species; and at any one place
the various species, both of animals and plants, have a number of
relations and mutual dependences arising out of these differences.
But besides the differences of this kind, we find in the forms of
organic life another set of differences, by which the animal and
vegetable kingdom are fitted for that variety in the climates of
the earth, which we have been endeavouring to explain.
The existence of such differences is too obvious to require to be
dwelt upon. The plants and animals which flourish and thrive in
countries remote from each other, offer to the eye of the traveller
a series of pictures, which, even to an ignorant and unreflective
spectator, is full of a peculiar and fascinating interest in
consequence of the novelty and strangeness of the successive scenes.
Those who describe the countries between the tropics, speak with
admiration of the luxuriant profusion and rich variety of the
vegetable productions of those regions. Vegetable life seems there
far more vigorous and active, the circumstances under which it goes
on, far more favourable than in our latitudes. Now if we conceive
an inhabitant of those regions, knowing, from the circumstances
of the earth’s form and motion, the difference of climates which
must prevail upon it, to guess, from what he saw about him, the
condition of other parts of the globe as to vegetable wealth, is
not likely that he would suppose that the extra-tropical climates
must be almost devoid of plants? We know that the ancients, living
in the temperate zone, came to the conclusion that both the torrid
and the frigid zones must be uninhabitable. In like manner the
equatorial reasoner would probably conceive that vegetation must
cease, or gradually die away, as he should proceed to places
further and further removed from the genial influence of the sun.
The mean temperature of his year being about 80 degrees, he would
hardly suppose that any plants could subsist through a year, where
the mean temperature was only 50, where the temperature of the
summer quarter was only 64, and where the mean temperature of a
whole quarter of the year was a very few degrees removed from that
at which water becomes solid. He would suppose that scarcely any
tree, shrub, or flower could exist in such a state of things, and
so far as the plants of his own country are concerned, he would
judge rightly.
But the countries further removed from the equator are not left
thus unprovided. Instead of being scantily occupied by such of the
tropical plants as could support a stunted and precarious life
in ungenial climes, they are abundantly stocked with a multitude
of vegetables which appear to be constructed expressly for them,
inasmuch as these species can no more flourish at the equator than
the equatorial species can in these temperate regions. And such
new supplies thus adapted to new conditions, recur perpetually
as we advance towards the apparently frozen and untenantable
regions in the neighbourhood of the pole. Every zone has its
peculiar vegetables; and as we miss some, we find others make their
appearance, as if to replace those which are absent.
If we look at the indigenous plants of Asia and Europe, we find
such a succession as we have here spoken of. At the equator we
find the natives of the Spice Islands, the clove and nutmeg trees,
pepper and mace. Cinnamon bushes clothe the surface of Ceylon; the
odoriferous sandal wood, the ebony tree, the teak tree, the banyan,
grow in the East Indies. In the same latitudes in Arabia the Happy
we find balm, frankincense and myrrh, the coffee tree, and the
tamarind. But in these countries, at least in the plains, the trees
and shrubs which decorate our more northerly climes are wanting.
And as we go northwards, at every step we change the vegetable
group, both by addition and by subtraction. In the thickets to the
west of the Caspian Sea we have the apricot, citron, peach, walnut.
In the same latitude in Spain, Sicily, and Italy, we find the
dwarf palm, the cypress, the chestnut, the cork tree: the orange
and lemon tree perfume the air with their blossoms; the myrtle
and pomegranate grow wild among the rocks. We cross the Alps, and
we find the vegetation which belongs to northern Europe, of which
England is an instance. The oak, the beech, and the elm are natives
of Great Britain: the elm tree seen in Scotland, and in the north
of England, is the wych elm. As we travel still further to the
north the forests again change their character. In the northern
provinces of the Russian empire are found forests of the various
species of firs: the Scotch and spruce fir, and the larch. In the
Orkney Islands no tree is found but the hazel, which occurs again
on the northern shores of the Baltic. As we proceed into colder
regions we still find species which appear to have been made for
these situations. The hoary or cold elder makes its appearance
north of Stockholm: the sycamore and mountain ash accompany us to
the head of the gulf of Bothnia: and as we leave this and traverse
the Dophrian range, we pass in succession the boundary lines of the
spruce fir, the Scotch fir, and those minute shrubs which botanists
distinguish as the dwarf birch and dwarf willow. Here, near to or
within the arctic circle, we yet find wild flowers of great beauty;
the mezereum, the yellow and white water lily, and the European
globe flower. And when these fail us, the reindeer moss still makes
the country habitable for animals and man.
We have thus a variety in the laws of vegetable organization
remarkably adapted to the variety of climates; and by this
adaptation the globe is clothed with vegetation and peopled with
animals from pole to pole, while without such an adaptation
vegetable and animal life must have been confined almost, or
entirely, to some narrow zone on the earth’s surface. We conceive
that we see here the evidence of a wise and benevolent intention,
overcoming the varying difficulties, or employing the varying
resources of the elements, with an inexhaustible fertility of
contrivance, a constant tendency to diffuse life and well being.
2. One of the great uses to which the vegetable wealth of the earth
is applied, is the support of man, whom it provides with food and
clothing; and the adaptation of tribes of indigenous vegetables
to every climate has, we cannot but believe, a reference to the
intention that the human race should be diffused over the whole
globe. But this end is not answered by indigenous vegetables alone;
and in the variety of vegetables capable of being _cultivated_ with
advantage in various countries, we conceive that we find evidence
of an additional adaptation of the scheme of organic life to the
system of the elements.
The cultivated vegetables, which form the necessaries or luxuries
of human life, are each confined within limits, narrow, when
compared with the whole surface of the earth; yet almost every part
of the earth’s surface is capable of being abundantly covered with
one kind or other of these. When one class fails, another appears
in its place. Thus corn, wine, and oil, have each its boundaries.
Wheat extends through the old Continent, from England to Thibet:
but it stops soon in going northwards, and is not found to succeed
in the west of Scotland. Nor does it thrive better in the torrid
zone than in the polar regions: within the tropics, wheat, barley
and oats are not cultivated, excepting in situations considerably
above the level of the sea: the inhabitants of those countries have
other species of grain, or other food. The cultivation of the vine
succeeds only in countries where the annual temperature is between
50 and 63 degrees. In both hemispheres, the profitable culture
of this plant ceases within 30 degrees of the equator, unless in
elevated situations, or in islands, as Teneriffe. The limits of the
cultivation of maize and of olives in France are parallel to those
which bound the vine and corn in succession to the north. In the
north of Italy, west of Milan, we first meet with the cultivation
of rice; which extends over all the southern part of Asia, wherever
the land can be at pleasure covered with water. In great part of
Africa millet is one of the principal kinds of grain.
Cotton is cultivated to latitude 40 in the new world, but extends
to Astrachan in latitude 46 in the old. The sugar cane, the
plantain, the mulberry, the betel nut, the indigo tree, the tea
tree, repay the labours of the cultivator in India and China;
and several of these plants have been transferred, with success,
to America and the West Indies. In equinoctial America a great
number of inhabitants find abundant nourishment on a narrow space
cultivated with plantain, cassava yams, and maize. The bread fruit
tree begins to be cultivated in the Manillas, and extends through
the Pacific; the sago palm in the Moluccas, the cabbage tree in the
Pelew islands.
In this manner the various tribes of men are provided with
vegetable food. Some however live on their cattle, and thus make
the produce of the earth only mediately subservient to their
wants. Thus the Tartar tribes depend on their flocks and herds for
food: the taste for the flesh of the horse seems to belong to the
Mongols, Fins, and other descendants of the ancient Scythians: the
locust eaters are found now, as formerly, in Africa.
Many of these differences depend upon custom, soil, and other
causes with which we do not here meddle; but many are connected
with climate: and the variety of the resources which man thus
possesses, arises from the variety of constitution belonging to
cultivable vegetables, through which one is fitted to one range of
climate, and another to another. We conceive that this variety and
succession of fitness for cultivation, shows undoubted marks of a
most foreseeing and benevolent design in the Creator of man and of
the world.
3. By differences in vegetables of the kind we have above
described, the sustentation and gratification of man’s physical
nature is copiously provided for. But there is another
circumstance, a result of the difference of the native products of
different regions, and therefore a consequence of that difference
of climate on which the difference of native products depends,[5]
which appears to be worthy our notice. The difference of the
productions of different countries has a bearing not only upon the
physical, but upon the social and moral condition of man.
The intercourse of nations in the way of discovery, colonization,
commerce; the study of the natural history, manners, institutions
of foreign countries; lead to most numerous and important results.
Without dwelling upon this subject, it will probably be allowed
that such intercourse has a great influence upon the comforts, the
prosperity, the arts, the literature, the power, of the nations
which thus communicate. Now the variety of the productions of
different lands supplies both the stimulus to this intercourse, and
the instruments by which it produces its effects. The desire to
possess the objects or the knowledge which foreign countries alone
can supply, urges the trader, the traveller, the discoverer to
compass land and sea; and the progress of the arts and advantages
of civilization consists almost entirely in the cultivation, the
use, the improvement of that which has been received from other
countries.
This is the case to a much greater extent than might at first sight
be supposed. Where man is active as a cultivator, he scarcely ever
bestows much of his care on those vegetables which the land would
produce in a state of nature. He does not select some of the plants
of the soil and improve them by careful culture, but, for the most
part, he expels the native possessors of the land, and introduces
colonies of strangers.
Thus, to take the condition of our own part of the globe as an
example; scarcely one of the plants which occupy our fields and
gardens is indigenous to the country. The walnut and the peach
come to us from Persia; the apricot from Armenia: from Asia
Minor, and Syria, we have the cherry tree, the fig, the pear, the
pomegranate, the olive, the plum, and the mulberry. The vine which
is now cultivated is not a native of Europe; it is found wild on
the shores of the Caspian, in Armenia and Caramania. The most
useful species of plants, the _cereal_ vegetables, are certainly
strangers, though their birth place seems to be an impenetrable
secret. Some have fancied that barley is found wild on the banks
of the Semara, in Tartary, rye in Crete, wheat at Baschkiros, in
Asia; but this is held by the best botanists to be very doubtful.
The potatoe, which has been so widely diffused over the world in
modern times, and has added so much to the resources of life in
many countries, has been found equally difficult to trace back to
its wild condition.
Thus widely are spread the traces of the connexion of the progress
of civilization with national intercourse. In our own country a
higher state of the arts of life is marked by a more ready and
extensive adoption of foreign productions. Our fields are covered
with herbs from Holland, and roots from Germany; with Flemish
farming and Swedish turnips; our hills with forests of the firs of
Norway. The chestnut and poplar of the south of Europe adorn our
lawns, and below them flourish shrubs and flowers from every clime
in profusion. In the mean time Arabia improves our horses, China
our pigs, North America our poultry, Spain our sheep, and almost
every country sends its dog. The products which are ingredients
in our luxuries, and which we cannot naturalize at home, we raise
in our colonies; the cotton, coffee, sugar of the east are thus
transplanted to the farthest west; and man lives in the middle of a
rich and varied abundance which depends on the facility with which
plants and animals and modes of culture can be transferred into
lands far removed from those in which nature had placed them. And
this plenty and variety of material comforts is the companion and
the mark of advantages and improvements in social life, of progress
in art and science, of activity of thought, of energy of purpose,
and of ascendancy of character.
The differences in the productions of different countries which
lead to the habitual intercourse of nations, and through this
to the benefits which we have thus briefly noticed, do not all
depend upon the differences of temperature and climate alone. But
these differences are among the causes, and are some of the most
important causes, or conditions, of the variety of products; and
thus that arrangement of the earth’s form and motion from which
the different climates of different places arises, is connected
with the social and moral welfare and advancement of man.
We conceive that this connexion, though there must be to our
apprehension much that is indefinite and uncertain in tracing
its details, is yet a point where we may perceive the profound
and comprehensive relations established by the counsel and
foresight of a wise and good Creator of the world and of man, by
whom the progress and elevation of the human species was neither
uncontemplated nor uncared for.
4. We have traced, in the variety of organized beings, an
_adaptation_ to the variety of climates, a _provision_ for the
sustentation of man all over the globe, and an _instrument_ for
the promotion of civilization and many attendant benefits. We have
not considered this _variety_ as _itself_ a purpose which we can
perceive or understand without reference to some ulterior end. Many
persons, however, and especially those who are already in the habit
of referring the world to its Creator, will probably see something
admirable in itself in this vast variety of created things.
There is indeed something well fitted to produce and confirm a
reverential wonder, in these apparently inexhaustible stores of
new forms of being and modes of existence; the fixity of the laws
of each class, its distinctness from all others, its relations to
many. Structures and habits and characters are exhibited, which are
connected and distinguished according to every conceivable degree
of subordination and analogy, in their resemblances and in their
differences. Every new country we explore presents us with new
combinations, where the possible cases seem to be exhausted; and
with new resemblances and differences, constructed as if to elude
what conjecture might have hit upon, by proceeding from the old
ones. Most of those who have any large portion of nature brought
under their notice in this point of view, are led to feel that
there is, in such a creation, a harmony, a beauty, and a dignity,
of which the impression is irresistible; which would have been
wanting in any more uniform and limited system such as we might try
to imagine; and which of itself gives to the arrangements by which
such a variety on the earth’s surface is produced, the character of
well devised means to a worthy end.