The analogy between the systems of vegetation in these,
three southern countries, depends, as ,the observations of M.
Leschenault would lead us to suppose, and as those of Mr.
Brown demonstrate, on the same sort of correspondences;
as those above described. There are very characteristic and
extensively diffused tribes in either country, which are wholly
wanting in the other. Such are, in New Holland, the genus
Eucalyptus, and the leafless Acaciæ, each consisting • of
about one hundred species already known. . Thèse, taken
together, comprise, according to Mr. Brown, in.respect to
numbers, and the vegetable matter they contain, nearly one
half of the whole_vegetation of Terra Australis. No traces qf
them have been found in South Africa. That country, On the
other hand, has several genera, very characteristic o f its
vegetation, which are entirely wanting in New Hollandr In
other, instances, certain, families in one region replacé anal'on
gous tribes in the other. The Bpacridefce, one hundxedjand
forty species of wh ich are nearly confined to Terra Australis^
appear there as substitutes for the Ericeae, a numerous and
diversified order in South Africa.
We are informed by Mr. Brown, th at the general.character
o f South American vegetation probably; recedes more from
the. Australian than the latter does from "the South. .African.
Yet, in Chili and Tierra deUFuego, there are certain tribeSrOf
plants nearly corresponding to some Australian genera.
Paragraph 4.— Of species common, to distant countries-—
. enumeration of botanical provinces.
The instances already collected are sufficient.fr> .prove, that
the general law of nature is the distribution o f different,“
un feuillage sec, rude, grêle, aromatique, à folioles presque toujours simples : par
toute la terre en effet, les mimosas ont des feuilles composées, mais il êtoit donné à
la Nouvelle Hollande d’en produire un grand nombre à pétiole devenu feuille simple.
Cettecoupe similaire donnée à la foliaison semble êtreaccommodée à la sécheresse
du sol, et destinée à multiplier les surfaces par pu s’opère.la nutrition du végétal.”
“ En dernier résultat,” concludes M. Lesson, “ les forêts de l’Australie ont quelque
chose de triste et de brumeaux qui fatigue la vue: la teinte du feuillage est d’un
vert glauque, monotone : les rameaux sont à demi dépouillés de, leur? écorces fongueuses,
ou celles-ci se détachent par lanières.qui flottent au gré des vents.”
though analogous species, to separated regions where the physical
conditions are similar. We .might almost venture to
eônsider those cases', in which the same identical species are
found in diffèrent continents; in the light of exceptions to a
general fact.- But the nature; of these instances must first be O''.:: .. y Sjaa ,
examined.
, Very many plants of simple structure are widely diffused,
the same 'species existing ■ in- distant countries. This fact
struck -the observation of Linnoeus, who'says, “ Miramur
muscbs’, fungos*; byssumfet mucorem ubiqufe ctescere/’ A similar
remark has been.thé rêsult of extensive researches made
by modern travellers, and it has been fully,confirmed by M.
de Humboldt and Mr. Robert Brown. It is now well known
to;h è 'a general: fact/ that cellular or agampus plants, which
are looked iipon as1 the lowest , orders in the vegetable crea-
tiofffor as those óf móst simple structure, are extensively dis-
péfeédï—Twö.thirds of theXichenbsæ obse^yeÿ'in Terra Australis
are alSo natives of Europe., }.0f the Musci and Bep&r
tic ^ o h è .third?part,-and of the submerged Algæ foupd on the
shores bffNew Holland one sixth-are European species; and
o f 'th e ’discovered Ferns oft the same region, which exceed
oàè hundrèd 'species, twenty-eight have been recognised in
othër cóuntrïèé.#"
^ îlâ n y of the monocotyledonous tribes likewise are widely
d'ifesed^ Manyf Grasses and CÿpeYacèm' are bónimon to Europe,
and-to Terra Australis^and to South America. M. de
Humboldt found not only Nl'dsses; but; Grasses and Cype-
racese which are well known dfe European species^ a
Very different are the facts .established in regard' to t |p
dicotyledonous' tribes found in various {countries :Vÿet!à few
of these are common to distant regions.
It has been observed by M. de Humboldt; that in comparing
the yegetation of file old and new continents, a general
fact may be recognised, parallel to that , which was observed
by the Count de Buffon in respect to.the distribution of ani-
mals-f*. It is;principally in thé àrdtic regions where the two
* General Remarks on /the Botany of Terra Australis, by R. Brown, Esq.
F.R.S. Appendix to Elinders* Voyage, p. 591.
Quod ad plantas phanérogames attinet, ferè eidem legi subjectas esse videas,
quarii disèrtus naturæ interpTes, Buffon, iti animalibUS zonae tortidæ, ynù habere