Digitale Ausgabe
Download
| TEI-XML (Ansicht) | |
| Text (Ansicht) | |
| Text normalisiert (Ansicht) |
Ansicht
| Textgröße | |
| Originalzeilenfall ein/aus | |
| Zeichen original/normiert | |
Zitierempfehlung
Alexander von Humboldt: „Humboldt on the Geography of Plants“, in: ders., Sämtliche Schriften digital, herausgegeben von Oliver Lubrich und Thomas Nehrlich, Universität Bern 2021. URL: <https://humboldt.unibe.ch/text/1816-Sur_les_lois-6-neu> [abgerufen am 25.04.2024].
URL und Versionierung
|
Permalink: https://humboldt.unibe.ch/text/1816-Sur_les_lois-6-neu |
| Die Versionsgeschichte zu diesem Text finden Sie auf github. |
| Titel | Humboldt on the Geography of Plants | ||||||
|---|---|---|---|---|---|---|---|
| Jahr | 1819 | ||||||
| Ort | Edinburgh | ||||||
|
Nachweis in: Blackwood’s Edinburgh Magazine 5:27 (Juni 1819), S. 354–355.
|
|||||||
| Sprache | Englisch | ||||||
| Typografischer Befund | Antiqua; Spaltensatz; Schmuck: Kapitälchen. | ||||||
|
Identifikation |
|||||||
Statistiken
|
|||||||
|354||Spaltenumbruch|
Alexander Count Humboldt has submit-ted to the Institute a curious paper, on thelaws observed in the distribution of vegetableforms over the globe. Botany, long con-fined to the simple description of the exter-nal forms of plants, and their artificial clas-sification, now presents several branches ofstudy, which place it more on a footing withthe other sciences. Such are the distribu-tion of vegetables, according to a naturalmethod founded upon the whole part oftheir structure; physiology, which displaystheir internal organization; botanical geo-graphy, which assigns to each tribe of plantstheir height, limits, and climate. Theterms alpine plants, plants of hot countries,plants of the sea-shore, are to be found inall languages, even in those of the most sa-vage nations on the banks of the Oronoko.They prove that the attention of men hasbeen constantly fixed on the distribution ofvegetables, and on their connexion with thetemperature of the air, the elevation of thesoil, and the nature of the ground whichthey inhabit. It does not require much sa-gacity to observe, that on the slope of thehigh mountains of Armenia, vegetables ofa different latitude follow each in succession,like the climates, superposed, as it were,upon each other.
The vegetables, says he, which cover thevast surface of the globe, present, when westudy by natural classes or families, strikingdifferences in the distribution of their forms.On limiting them to the countries in whichthe number of the species is exactly known,and by dividing this number by that of theglumaceæ, the leguminous plants, the la-biated, and the compound, we find nume-rical relations which form very regular se-ries. We see certain forms become morecommon, from the equator towards the pole,like the ferns, the glumaceæ, the ericineæ,and the rhododendrons. Other forms, onthe contrary, increase from the poles to-wards the equator, and may be consideredin our hemisphere as southern forms: suchare the rubiaceæ, the malvaceæ, the eu-phorbia, the leguminous, and the compo-site plants. Finally, others attain theirmaximum even in the temperate zone, anddiminish also towards the equator and thepoles; such are the labiated plants, theamentaceæ, the cruciferæ, and the umbel-liferæ. The grasses form in England 1-12th,in France 1-13th, in North America 1-10th,of all the phanerogamous plants. The glu-maceæ form in Germany 1-7th, in France1-8th, in North America 1-8th, in New|Spaltenumbruch|Holland, according to the researches of MrBrown, 1-8th, of the known phanerogamousplants. The composite plants increase alittle in the northern part of the new con-tinent; for, according to the new Flora ofPursch, there is between the parallels ofGeorgia and Boston 1-6th, whereas in Ger-many we find 1-8th, and in France 1-7th,of the total number of the species, with vi-sible fructification. In the whole temperatezone, the glumaceæ and the compositeplants, form together, nearly one-fourth ofthe phanerogamous plants; the glumaceæ,the compositæ, the cruciferæ, and the legu-minosæ, together, nearly one-third. It re-sults from these researches, that the formsof organized beings are in a mutual de-pendence; and that the unity of nature issuch, that the forms are limited, the oneafter the other, according to constant lawseasy of determination.
The number of vegetable species describ-ed by botanists, or existing in Europeanherbals, extends to 44,000, of which 6000are agamous. In this number we had al-ready included 3000 new phanerogamousspecies enumerated by M. Bompland andmyself. France, according to M. Decan-dolle, possesses 3645 phanerogamous plants,of which 460 are glumaceæ, 490 composite,and 230 leguminous, &c. In Lapland thereare only 497 phanerogamous plants; amongwhich are 124 glumaceæ, 58 composite, 14leguminous, 23 amentaceous, &c.
Mr Pursch has made us acquainted with2000 phanerogamous plants which grow be-tween the parallels of 35° and 44°; con-sequently, under mean annual temperaturesof 16° and 7°. The flora of North Ame-rica is a mixture of several floras. Thesouthern regions give it an abundance ofmalvaceæ and composite plants; the north-ern regions, colder than Europe, under thesame parallel, furnish to this flora abund-ance of rhododendrons, amentaceæ, and co-niferæ. The caryophylleæ, the umbelliferæ,and the cruciferæ, are in general more rarein North America, than in the temperatezone of the old continent.
These constant relations observed on thesurface of the globe, in the plains from theequator to the pole, are again traced in themidst of perpetual snows on the summits ofmountains. We may admit, in general,that on the cordilleras of the torrid zone,the boreal forms become more frequent. Itis thus that we see prevail at Quito, on thesummit of the Andes, the ericineæ, the rho-dodendrons, and the gramineous plants. Onthe contrary, the labiatæ, the rubiaceæ, themalvaceæ, and the euphorbiaceæ, then be-come as rare as they are in Lapland. Butthis analogy is not supported in the fernsand the composite plants. The latter a-bound on the Andes, whereas the formergradually disappear when they rise above1800 fathoms in height. Thus the climateof the Andes resembles that of northern Eu-rope only with respect to the mean tem-
|355||Spaltenumbruch|perature of the year. The repartition ofheat into the different seasons is entirelydifferent, and powerfully influences the phe-nomena of vegetation. In general, theforms which prevail among the alpine plants,are, according to my researches, under thetorrid zone, the graminæ (ægopogon, podo-sæmum, deyeuxia, avena); the compositæ(calcitium, espeletia, aster, baccharis); andthe caryophylle (arenaria, stellaria.) Underthe temperate zone, the compositæ (senecio,leontodon, aster); the caryophylleæ (ceras-tium, cherleria, silene); and the cruciferæ(draba, lepidium.) Under the frozen zone,the caryophyllæ (stellaria, alsine); the eri-cineæ (andromeda), and the ranunculaceæ.It has been long known, and it is one ofthe most interesting results from the geo-graphy of animals, that no quadruped, noterrestrial bird, and, as appears from theresearches of M. Latreille, almost no insectis common to the equatorial regions of thetwo worlds. M. Cuvier is convinced, byprecise inquiries, that this rule applies evento reptiles. He has ascertained, that thetrue boa constrictor is peculiar to America;and that the boas of the old continent, werepytons. Among the plants, we must dis-tinguish between the agamæ and the cotyle-doneæ: and by considering the latter be-tween the monocotylodens and the dicotyle-dons. There remains no doubt that manyof the mosses and lichens are to be found atonce in equinoctial America and in Europe.But the case is not the same with the vascu-lar agamæ as with the agamæ of a cellulartexture. The ferns and the lycopodiaceædo not follow the same laws with the mossesand the lichens. The former, in particular,exhibit very few species universally to befound; and the examples cited are fre-quently doubtful. As to the phanerogamousplants (with the exception of the rhizophora,the avicennia, and some other littoralplants), the law of Buffon seems to be exactwith respect to the species furnished withtwo cotyledons. It is absolutely false, al-though it has been often affirmed, that theridges of the cordilleras of Peru, the climateof which has some analogy with the climateof France or Sweden, produce similar plants.The oaks, the pines, the yews, the ranun-culi, the rose-trees, the alchemilla, the va-lerians, the stellaria, the draba of thePeruvian and Mexican Andes, havenearly the same physiognomy with thespecies of the same genera of North A-merica, Siberia, or Europe. But allthese alpine plants of the cordilleras, with-out excepting one among three or fourthousand which we have examined, differspecifically from the analogous species of thetemperate zone of the old continent. Ingeneral, in that part of America situated be-tween the tropics, the monocotyledontalplants alone, and among the latter almostsolely the cyperaceæ and the gramineæ, arecommon to the two worlds. These two fa-milies form an exception to the general law|Spaltenumbruch|which we are here examining,—a law whichis so important for the history of the catas-trophes of our planet, and according towhich, the organized beings of the equi-noctial regions differ essentially in the twocontinents.
Humboldt on the Geography of Plants.—