which extend over the desert steppes of Northern Asia -- grasses, and cacti
growing
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together like the pipes of an organ -- Avicennim and mangroves in the
tropics -- and forests of Coniferae and of birches in the plains of the
Baltic and in Siberia. This mode of geographical distribution determines,
together with the individual form of the vegetable world, the size and type
of leaves and flowers, in fact, the principal physiognomy of the district,*
its characteracter being but little, if at all, influenced by the
ever-moving forms of animal life, which, by their beauty and diversity, so
powerfully affect the feelings of man, whether by exciting the sensations of
admiration or horror.
[footnote] *On the physiognomy of plants, see Humboldt, 'Anischten der
Natur', bd. ii., s. 1-125.
Agricultural nations increase artificially the predominance of social
plants, and thus augment, in many parts of the temperate and northern zones,
the natural aspect of uniformity; and while their labors tend to the
extirpation of some wild plants, they likewise lead to the cultivation of
others, which follow the colonist in his most distant migration. The
luxuriant zone of the tropics offers the strongest resistance to these
changes in the natural distribution of vegetable forms.
Observers who in short periods of time have passed over vast tracts of land,
and ascended lofty mountains, in which climates were ranged, as it were in
strata one above another, must have been early impressed by the regularity
with which vegetable forms are distributed. The results yielded by their
observations furnished the rough materials for a science, to which no name
had as yet been given. The same zones of regions of vegetation which, in
the sixteenth century, Cardinal Bembo, when a youth,*described on the
declivity of Aetna, were observed on Mount Ararat by Tournefort.
[footnote] *Aetna Dialogus.' 'Opuscula', Basil., 1556, p. 53, 54. A very
beautiful geography of the plants of Mount AEtna has recently been published
by Philippi. See 'Linnaea', 1832, s. 733.
He ingeniously compared the Alpine flora with the flora of plains situated
in different latitudes, and was the first to observe the influence exercised
in mountainous regions, on the distribution of plants by the elevation of
the ground above the level of the sea, and by the distance from the poles in
flat countries. Menzel, in an inedited work on the flora of Japan,
accidentally made use of the term 'geography of plants'; and the same
expression occurs in the fanciful but graceful work of Bernardin de St.
Pierre, 'Etudes de la Nature'. A scientific treatment of the subject began,
however, only when the geography of plants was intimately associated with
the study of the distribution
p 348
of heat over the surface of the earth, and when the arrangement of vegetable
forms in natural families admitted of a numerical estimate being made of the
different forms which increase of decrease as we recede from the equator
toward the poles, and of the relations in which, in diffrent parts of the
earth, each family stood with reference to the whole mass of phanerogamic
indigenous plants of the same region. I consider it a happy circumstance
that, at the time during which I devoted my attention almost exclusively to
botanical pursuits, I was led by the aspect of the grand and strongly
characterized features of tropical scenery to direct my investigations
toward these subjects.
The study of the geographical distribution of animals, regarding which
Buffon first advanced general, and, in most instances, very correct views,
has been considerably aided in its advance by the progress made in modern
times in the geography of plants. The curves of the isothermal lines, and
more especially those of the isochimenal lines, correspond with the limits
which are seldom passed by certain species of plants, and of animals which
do not wander far from their fixed habitation either with respect to
elevation or latitude.*
[footnote] *[The following valuable remarks by Professor Forbes, on the
correspondence existing between the distribution of existing faunas and
floras of the British Islands, and the geological changes that have affected
their area, will be read with much interest; they have been copied, by the
author's permission, from the 'Survey Report', p. 16:
"If the view I have put forward respecting the origin of the flora of the
British mountains be true -- and every geological and botanical probability,
so far as the are is concerned, favors it -- then must we endeavour to find
some more plausible cause than any yet shown for the presence of numerous
species of plants, and of some animals, on the higher parts of Alpine ranges
in Europe and Asia, specifically identical with animals and plants
indigenous in the regions very far north, and not found in the intermediate
lowlands. Tournefort first remarked and Humboldt, the great organizer of
the science of natural history geography, demonstrated, that zones of
elevation on mountains correspond to parallels of latitude, the higher with
the more northern or southern, as the case might be. It is well known that
this correspondence is recognized in the general 'facies' of the flora and
fauna, dependent on generic identities. But when announcing and
illustrating the law that climatal zones of animal and vegetable life are
mutually repeated or represented by elevation and latitude, naturalists have
not hitherto sufficiently (if at all) distinguished between the evidence of
that law, as exhibited by 'representative species' and by 'identical'. In
reality, the former essentially depend on the law, the latter being an
'accident' not necessarily dependent upon it, and which has hitherto not
been accounted for. In the case of the Alpine flora of Britain, the
evidence of the activity of the law, and the influence of the accident, are
inseparable, the law being maintained by a transported flora, for the
transmission of which I have shown we can not account by an appeal to
unquestionable geological events. In the case of the Alps and Carpathians,
and some other mountain ranges, we find the law maintained partly by a
representative flora, special in its region, i.e., by specific centers of
their own, and partly by an assemblage more or less limited in the several
ranges of identical species, these latter in several cases so numerous that
ordinary modes of transportation now in action can no more account for their
presence than they can for the presence of a Norwegian flora on the British
mountains. Now I am prepared to maintain that the same means which
introduced a sub-Arctic (now mmountain) flora into Britain, acting at the
same epoch, originated the identity, as far as it goes, of the Alpine floras
of middle Europe and Central Asia; for, now that we know the vast area swept
by the glacial sea, including almost the whole of Central and Northern
Europe, and belted by land, since greatly uplifted, which then presented to
the water's edge those climatal lconditions for which a sub-Arctic flora --
destined to become Alpine -- was specially organized, the difficulty of
deriving such a flora from its paarent north, and of diffusing it over the
snowy hills bounding this glacial ocean, vanishes, and the presence of
identical species at such distant pooints remain no longer a mystery.
Moreover, when we consider that conditions during the epoch referred to, the
undoubted evidences of Continental observers, on the boounds of Asia by Sir
Roderick Murchison, in America by Mr. Lyell, Mr. Logan, Captain Bayfield,
and others, and that the botanical (and zoological as well) region,
essentially northern and Alpine, designated by Professor Schouw that 'of
saxifrages and mosses,' and first in his classification, exists now only on
the flanks of the great area which suffered such conditions; and that,
though similar conditions reappear, the relationship of Alpine and Arctic
vegetation in the southern hemisphere, with that in the northern, is
entirely maintained by 'representative', and not by identical species (the
general truth of my explanation of Alpine floras, including identical
species, becomes so strong, that the view proposed acquires fair claims to
be ranked as a theory, and not considered merely a convenient or bold
hypothesis."] -- Tr.
The
p 349
elk, for instance, lives in the Scandinavian peninsula, almost ten degrees
further north than in the interior of Siberia, where the line of equal
winter temperature is so remarkably concave. Plants migrate in the germ;
and, in the case of many species, the seeds are furnished with organs
adapting them to be conveyed to a distace through the air. When once they
have taken root, they become dependent on the soil and on the strata of air
surrounding them. Animals, on the contrary, can at pleasure migrate from
the equator toward the poles; and this they can more especially doo where
the isothermal lines are much inflected, and where hot summers succeed a
great degree of winter cold. The royal tiger, which in no respect differs
from the Bengal species, penetrates every summer into
p 350
the north of Asia as far as the latitudes of Berlin and Hamburg, a fact of
which Ehrenberg and myself have spoken in other works.*
[footnote] *Ehrenberg, in the 'Annales des Sciences Naturelles', t. xxi.,
p. 387, 412; Humboldt, 'Asie Centrale', t. i., p. 339-342, and t. iii., p.
96-101.
The grouping or association of diffrent vegetable species, to which we are
accustomed to apply the term 'Floras', do not appear to me, from what I have
observed in different portions of the earth's surface, to manifest such a
predominance of individual families as to justify us in marking the
geographical distinctions between the regions of the Umbellatae, of the
Solidaginae, of the Labiatae, or the Scitamineae. With reference to this
subject, my views differ from those of several of my friends, who rank among
the most distinguished of the botanists of Germany. The character of the
floras of the elevated plateaux of Mexico, New Granada, and Quito, of
European Russia, and of Northern Asia, consists, in my opinion, not so much
in the relatively larger number of the species presented by one or two
natural families, as in the more complicated relations of the coexistence of
many families, and in the relative numerical value of their species. The
Gramineae and the Cyperaceae undoubtedly predominate in meadow lands and
stppes, as do Coniferae, Cupuliferae, and Betulineae in our northern woods;
but this predominance of certain forms is only apparent, and owing to the
aspect imparted by the social plants. The north of Europe, and that portion
of Siberia which is situated to the north of the Altai Mountains, have no
greater right to the appellation of a region of Gramineae and Coniferae than
have the boundless llanos between the Orinoco and the mountain chain of
Caraccas, or the pine forests of Mexico. It is the coexistence of forms
which may partially replace each other, and their relative numbers and
association, which give rise either to the general impression of luxuriance
and diversity, or of poverty and uniformity in the contemplation of the
vegetable world.
In this fragmentary sketch of the phenomena of organization, I have ascended
from the simplest cellI -- the first manifestation of life -- progressively
to higher structures. "The
p 351
association of mucous granules constitutes a definitely-formed cytoblase,
around which a vesicular membrane forms ia closed well," this cell being
either produced from another pre-existing cell,** or being due to a cellular
formation, which, as in the case of the fermentation-fungus, is concealed in
the obscurity of some unknown chemical process.***
[footnote] *Schleiden, 'Ueber die Entwicklungsweise der Pflanzenzellen', in
Muller's 'Archiv fur Anatomie und Physiologie', 1838, s. 137-176; also his
'Grundzuge der wissenschaftlichen Botanik', th. i., s. 191, and th. ii., s
11. Schwann, 'Mikroscopische Untersucungen uber die Uebereinstimmung in der
Struktur und dem Wachsthum der Thiere und Pflanzen', 1839, s. 45, 220.
Compare also, on similar propagation, Joh. Muller 'Physiologie des
Menschen', 1840, th. ii., s. 614.
[footnote] **Schleiden, 'Grundzuge der wissenschaftlichen Botanik', 1842,
th. i., s. 192-197.
[footnote] ***[On cellular formation, see Henfrey's 'Outlines of Structural
and Physiological Botany', op. cit., p. 16-22.] -- Tr.
But in a work like the present we can venture on no more than an allusion to
the mysteries that involve the question of modes of origin; the geography of
animal and vegetable organisms must limit itself to the consideration of
germs already developed, of their haabitation and transplantation, either by
voluntary or involuntary migrations, their numerical relation, and their
distribution over the surface of the earth.
The general picture of nature which I have endeavored to delineate would be
incomplete if I did not venture to trace a few of the most marked features
of the human race, considered with reference to physical gradations -- to
the geographical distribution of contemporaneous types -- to the influence
exercised upon man by the forces of nature, and the reciprocal, although
weaker action which he in his turn exercises on these natural forces.
Dependent, although in a lesser degree than plants and animals, on the soil,
and on the meteorological processes of the atmosphere with which he is
surroounded -- escaping more readily from the control of natural forces, by
activity of mind and the advance of intellectual cultivation, no less than
by his wonderful capacity of adapting himself to all climates -- man every
where becomes most essentially associated with terrestrial life. It is by
these relations that the obscure and much-contested problem of the
possibility of one common descent enters into the sphere embraced by a
general physical cosmography. The investigation of this problem will impart
a nobler, and, if I may so express myself, more purely human interest to the
closing pages of this section of my work.
The vast domain of language, in whose varied structure we see mysteriously
reflected the destinies of nations, is most intimately associated with the
affinity of races; and what even slight differences of races may effect is
strikingly manifested in the history of the Hellenic nations in the zenith
of their intellectual cultivation. The most important questions of the
civilization of mankind are connected with the ideas of races,
p 352
community of language, and adherence to one original direction of the
intellectual and moral faculties.
As long as attention was directed solely to the extremes in varieties of
color and of form, and to the vividness of the first impression of the
senses, the observer was naturally disposed to regard races rather as
originally different species than as mere varieties. The permanence of
certain types* in the midst of the most hostile influences, especially of
climate, appeared to favor such a view, notwithstanding the shortness of the
interval of time from which the historical evidence was derived.
[footnote] *Tacitus, in his speculations on the inhabitants of Britain
('Agricola', cap. ii.), distinguishes with much judgment between that which
may be owing to the local climatic relations, and that which, in the
immigrating races, may be owing to the unchangeable influence of a
hereditary and transmitted type. "Britanniam qui mortales initio coluerunt,
indigenae an advecti, ut inter barbaros, parum coompertum. Habitus
corporis varii, alque ex eo argumenta; namque rutilae Caledoniam habitantium
comae, magni artus Germanicam originem adseverant. Silu ram colorati vultus
et torti plerumque crines, et posita contra Hispania, Iberos veteres
trajecisse, easque cedes occupasse fidem faciunt: proximi Gallis, et
similes sunt: seu durante originis vi; seu procurrentibus in diversa
terris, positio coeli corporibus habitum dedit." Regarding the persistency
of types of conformation in the hot and cold regions of the earth, and in
the mountainous districts of the New Continent, see my 'Relation
Historique', t. i., p. 498, 503, and t. ii., p. 572, 574.
In my opinion, however, more powerful reasons can be advanced in support of
the theory of the unity of the human race, as, for instance, in the many
intermediate gradations* in the color of the skin and in the form of the
skull, which have been made known to us in recent times by the rapid
progress of geographical knowledge -- the analogies presented by the
varieties in the species of many wild and domesticated animals -- and the
more correct observations collected regarding the limits of fecundity in
hybrids.**
[footnote] On the American races generally, see the magnificent work of
Samuel George Morton, entitled 'Crania Americana', 1839, p. 62, 86; and on
the skulls brought by Pentland from the highlands ot titicaca, see the
'Dublin Journal of Medical and Chemical Science', vol. v., 1834, p. 475;
also Alcide d'Orbigny, 'L'homme Americain considere sous ses rapports
Physiol. et Mor.', 1839, p. 221; and the work by Prince Maximilian of Wied,
which is well worthy of notice for the admirable ethnographical remarks in
which it abounds, entitled 'Reise in das Innere von Nordamerika' (1839).
[footnote] ** Rudolph Wagner, 'Ueber Blendlinge und Bastarderzeugung', in
his notes to the German translation of Prichard's 'Physical History of
Mankind', vol. i., p. 138-150.
The greater number of the contrasts which were formerly supposed to exist,
have disappeared before the laborious researches of Tiedemann on the brain
of negroes and of Europeans, and the anatomical investigations
p 353
of Vrolik and Weber on the form of the pelvis. On comparing the
dark-colored African nations, on whose physical history the admirable work
of Prichard has thrown so much light, with the races inhabiting the islands
of the South-Indian and West-Australian archipelago, and with the Papuas and
Alfourous (Haroforas, Endamenes), we see that a black skin, woolly hair, and
a negro-like cast of countenance are not necessarily connected together.*
[footnote] *Prichard, op. cit., vol. ii., p. 324.
So long as only a small portion of the earth was known to the Western
nations, partial views necessarily predominated, and tropical heat and a
black skin consequently appeared inseparable. "The Ethiopians," said the
ancient tragic poet Theodectes of Phaselis,* "are colored by the near
sun-god in his course with a sooty luster, and their hair is dried and
crisped with the heat of his rays."
[footnote] *Onesicritus, in Strabo, xv., p. 690, 695, Casaub. Welcker,
'Griechische Tragodien', abth. iii., s. 1078, conjectures that the verses of
Theodectes, cited by Strabo, are taken from a list tragedy, which probably
bore the title of "Memnon."
The campaigns of Alexander, which gave rise to so many new ideas regarding
physical geography, likewise first excited a discussion on the problematical
influence of climate on races. "Families of animals and plants," writes one
of the greatest anatomists of the day, Johannes Muller, in his noble and
comprehensive work, 'Physiologie des Menschen', "undergo, within certain
limitations peculiar to the different races and species, various
modifications in their distribution over the surface of the earth,
propagating these variations as organic types of species.*
[footnote] *[In illustration of this, the conclusions of Professor Edward
Forbes respecting the origin and diffusion of the British flora may be
cited. See the 'Survey Memoir' already quoted, 'On the Connection between
the Distribution of the existing Fauna and Flora of the British Islands,
etc.', p. 64. "1. The flora and fauna, terrestrial and marine, of the
British islands and seas, have originated, so far as that area is concerned,
since the melocene epoch. 2. The assemblages of animals and plants
compositing that fauna and flora did not appear in the area they now inhabit
simultaneously, but at several distinct points in time. 3. Both the fauna
and flora of the British islands and seas are composed partly of species
which, either permanently or for a time, appeared in that area before the
glacial epoch; partly of such as inhabited it during that epoch; and in
great part of those which did not appear there until afterward, and whose
appearance on the earth was coeval with the elevation of the bed of the
glacial sea and the consequent climatal changes. 4. The greater part of
the terrestrial animals and flowering plants now inhabiting the British
islands are members of specific centers beyond their area, and have migrated
to it over continuous land before, during, or after the glacial epoch. 5.
The climatal conditions of the area under discussion, and north, east, and
west of it, were severer during the glacial epoch, when a great part of the
space now occupied by the British isles was under water, than they are now
or were before; but there is good reason to believe that, so far from those
conditions having continued severe, or having gradually diminished in
severity southward of Britain, the cold region of the glacial epoch came
directly into contact with a region of more southern and thermal character
than that in which the most southern beds of glacial drift are now to be met
with. 6. This state of things did not materially differ from that now
existing, under corresponding latitudes, in the North American, Atlantic,
and Arctic seas, and on their bounding shores. 7. The Alpine floras of
Europe and Asia, so far as they are identical with the flora of the Arctic
and sub-Arctic zones of the Old World, are fragments of a flora which was
diffused from the north, either by means of transport not now in action on
the temperate coasts of Europe, or over continuous land which no longer
exists. The deep sea fauna is in like manner a fragment of the general
glacial fauna. 8. The floras of the islands of the Atlantic region,
between the Gulf-weed Bank and the Old World, are fragments of the Great
Mediterranean flora, anciently diffused over a land consistuted out of the
upheaval and never again subjerged bed of the (shallow) Meiocene Sea. This
great flora, in the epoch anterior to, and probably, in part, during the
glacial period, had a greater extension northward than it now presents. 9.
The termination of the glacial epoch in Europe was marked by a recession of
an Arctic fauna and flora northward, and of a fauna and flora of the
Mediterranean type southward; and in the interspace thus produced there
appeared on land the Germanic fauna and flora, and in the sea that fauna
termed Celtic. 10. The causes which thus preceded the appearance of a new
assemblage of organized beings were the destruction of many species of
animals, and probably also of plants, either forms of extremely local
distribution, or such as were not capable of enduring many changes of
conditions -- species, in short, with very limited capacity for horizontal
or vertical diffusion. 11. All the changes before, during, and after the
glacial epoch appear to have been gradual, and not sudden, so that no marked
line of demarkation can be drawn between the creatures inhabiting the same
element and the same locality during two proximate periods."] -- Tr.
The different races of mankind are forms of one sole species, by the union
of two of whose members descendants are propagated. They are not different
species of a genus, since in that case their hybrid descendants would remain
unfruitful. But whether the human races have descended from several
primitive races of men, or from one alone, is a question that can not be
determined from experience."*
[footnote] *Joh. Muller, 'Physiologie des Menschen', bd. ii., s. 768.