r i
4. These three peciüiai’ities arc shai’ed by all the islands in the sontli temperate zone (inchiding
even Tristan d’Acunha, though placed so close to Africa), between which islands the transportation
of seeds is even more unlikely than between the larger masses of land.
5. The plants of the Antarctic islands, which ai-e equally natives of New Zealand, Tasmania,
and Australia, are almost invariably found only on the lofty mountains of these countries.
Now as not only individual species, h u t groups of these, whether orders, genera, or their subdivisions,
are to a great degree distributed within certain limits or areas, it follows th a t the flora of
every island or archipelago presents peculiarities of its own. Though an insular climate may
favour the relative abundance of indiriduals, and even species of certain Natural Orders, tbere is
nothing in the climate, or in any otber attribute of insularity, which indicates the nature of the
peculiarity of endemic species. Tbe islands of each ocean contain certain hotanicaUy aUied forms
in common, wliich are more or less abundant in them, and rai-ely or never found on the neighbouring
coutments; thus there are curious genera peculiar to the North Atlantic islands, others to
the North Pacific islands, others to those of the South Pacific, and others again to the Malayan
Archipelago; just as there are stUl others peculim- to the Antaretic islauds, and many to New
Zealand, Fuegia, and Tasmania.
Each group of islauds hence foi-ms a botanical region, more or less definable by its plants as
well as by its oceanic boundaiacs ; precisely as a continuous area like AustraUa or South Africa does.
There is however this difference, th a t whereas the Na tu ra l Orders th a t give a botanical character to
a continuous area of a continent or to a largo island (as the Proteaceæ in South Africa or in New
Holland, and Coprosma in New Zealand) are numerous in species and often uniformly spread,—in
clusters of smaU islands, distant from continents, they are few in species, and the individuals are
scattered, appearing as if the vestiges of a flora wHcli belonged to another epoch, and wdiioh is
passing away : this is perhaps a fanciful idea, but one which I believe to contain the germ of tru th ;
for no Botanist can reflect upon the destruction of peculiar species on small islands (such as is now
going on in St. Helena amongst others), without feeling that, as each disappears, a gap remains,
which may never be hotanicaUy refilled ; th a t not only are those links breaking by which he connects
the present flora with the past, hut also those by which he hinds the different members of the
vegetable kingdom one to another. I t is not true in every sense th a t all existing nature appeai-s to
the naturalist as an harmonious whole ; each species combines by its own peculiarities two or more
others more closely, and reveals their affinities more clearly, than any other does; ju s t as the flora
of an intermediate spot of land connects those of two adjacent areas better than any other locality
does. I t IS often by one or a very few species th a t two large Natural Orders are seen to be related;
ju st as by a few Chilian plants the whole flora of New Zealand is connected with th a t of South
America. The destruction of a speeies'must hence create an hiatus in our systems, and I believe
th a t It IS mamly through such losses th a t natural orders, genera, and species bocomo isolated, th a t is,
peculiar, in a natiu’alist’s eyes.
To return to the distribution of existing species, I cannot think th a t those who, arguing for
unlimited powers of migration in plants, think existing means ample for ubiquitous dispersion, sufficiently
appreciate the difficulties in the way of the necessary transport. During my voyages amongst
the Antarctic islands, I was led, by the constant recurrence of familiar plants in the most inaccessible
spots, to reflect much on the subject of tlieir possible transport; and the conviction was soon forced
upon me, that, putting aside the almost insuperable obstacles to trans-oceanic migration between such
islands as Iniegia and Kerguelen’s Land, for instance (which have plants in common, not found elsewhore),
there were such peculiarities in the plants so circumstanced, as rendered many of them
the least likely of all to have availed themselves of what possible chances of transport there may
have been. As species they were either not so abundant in individuals, or n ot prolific enough to have
been the first to offer themselves for chance transport, or their seeds presented no facilities for migration*,
or w-ere singularly perishable from feeble vitality, soft or brittle integuments, th e presence
of oil th a t soon became rancid, or from having a fleshy albumen th a t quickly decayedt- Added
to the fact th a t of all the plants in the respective floras of the Antarctic islands, those common to
any two of them were the most unlikely of all to emigrate, and th a t there were plenty of species
possessing unusual facilities, which had not availed themselves of them, there was another important
point, namely, the little chance there was of the seeds growing at all, after transport. Though
thousands of seeds are annually shed in those bleak regions, few indeed vegetate, and of these fewer
still arrive at matuiity. There is no annual plant in Kerguelen’s Land, and seedlings are extremely
rare th e re ; the seeds, if not eaten by birds, cither ro t on the ground or are washed away; and the
conclusion is evident, th a t if such mortality attends them in their own island, the chances must be
small indeed for a solitary individual, after being transported perhaps thousands of miles, to some
spot where the available soil is pre-occupied.
Beyond the bare fact of the difficulty of accounting by any other means for the presence of the
same species in two of the islands, there appeared notlung in the botany of the Antarctic regions to
support or even to favour the assumption of a double creation, and I lienee dismissed it as a mere
speculation which, till it gained some support on philosophical principles, could only he regarded as
shelving a difficulty; whilst the unstable doctrine th a t would account for the creation of each speeies
on each island by progressive development on the spot, was contradicted by every fact.
I t was with these conclusions before me, th a t I was led to speculate on the possibility of the
plants of the Southern Ocean being the remains of a flora th a t had once spread over a larger and
more continuous tract of land than now exists in th a t ocean; and th a t the peculiar Antarctic genera
and species may he the vestiges of a flora characterized by the predominance of plants whicli are
now scattered throughout th e southern islands. An allusion to these speculations was made in the
‘ Flora A ntarctica’ (pp. 210 and 368), w here some circumstances connected with the distribution of the
Antarctic islands were dwelt upon, and their resemblance to the summits of a submerged mountain
chain was pointed o u t; hut heyoud the facts th a t the general features of the flora favoured such
a view, th a t the difficulties in the way of transport appeared to admit of no other solution, and th a t
there are no hmits assignable to the age of the species th a t would make their creation posterior to
such a scries of geological changes as should remove the intervening land, there was nothing in
the shape of evidence by which my speculation could he supported. I am indebted to the invaluable
labours of LyeU and Darwin):, for the facts th a t could alone have given countenance to such
an hypothesis; the one showing th a t the necessary time and elevations and depressions of land
* Tims of the CoMpositm, common to Lord Auckland’s Group, Fuegia, and Kerguelen’s Land, none have any
pappus (or seed-down) at all! Of the many species with pappus, none are common to two of these islands !
t Of the seeds sent to England from the Antarctic regions, or transported by myself between the several islands,
almost all perished during transmission.
t See Darwin’s ‘ Journal of a Naturalist,’ and ‘ Essays on Volcanic Islands and Coral Islands.’ The proofs of
the coasts of Chili and Patagonia having been raised continuously, for several hundred miles, to elevations varying
between 400 and 1300 feet, since the period of the creation of existing shells, will be found in the first-named of
these admirable works, which should be in the hands of every New Zealand Naturalist, if only from its containing