562 TRANSACTIONS OF SECTION K. 
Australian Botany was the voyage of Ross, with the Hrebus and the “error ; for 
with him was Joseph Hooker, whose botanical work gave an added distinction to 
an otherwise remarkable expedition. 
The prime object of the voyage was a magnetic survey, and this determined 
its course. But in the intervals of sailing the Antarctic Seas the two ships 
visited Ascension Island, St, Helena, the Cape, New Zealand, Australia, Tas- 
mania, Kerguelen Island, Tierra del Fuego, and the Falkland Islands. Thus 
Hooker had the opportunity of collecting and observing upon all the great cir- 
cumpolar areas of the Southern Hemisphere. He welded together the results into 
his great work ‘The Antarctic Flora.’ It was published in six large quarto 
volumes. In them about 3,000 species are described, while on 530 plates 1,095 
species are depicted, usually with detailed analytical drawings. But these mag- 
nificent volumes did not merely contain reports of explorations, or descriptions 
of the many new species collected. There was much more than this in them. 
All the known facts that could be gathered were incorporated, so that they 
became systematically elaborated and complete Floras of the several countries. 
Moreover, in the last of them, the ‘Flora Tasmanie,’ there is an Introductory 
Essay, in which the Australasian Flora was for the first time treated as a whole, 
and its probable origin and its relation to other Floras discussed. Further, ques- 
tions of the mutability and origin of species were also raised in it. The air was 
full of such questions in 1859; the essay was completed in November of that year, 
less than twelve months after the joint communications of Darwin and Wallace 
had been made to the Linnean Society, and before the ‘ Origin of Species’ was 
published. It was to this essay that Darwin referred when he wrote that 
‘ Hooker has come round, and will publish his belief soon.’ But this publication 
of his belief in the mutability of species was not merely an echo of assent to 
Darwin’s own opinion. It was a reasoned statement, advanced upon the basis 
of his ‘ own self-thought,’ and his own wide systematic and geographical experi- 
ence. Irom these sources he drew support for ‘ the hypothesis that species are 
derivative and mutable.’ He points cut how the natural history of Australia 
seemed specially suited to test such a theory, on account of the comparative 
uniformity of the physical features being accompanied by a great variety in its 
Flora, and the peculiarity of both its Fauna and Flora, as compared with other 
countries. After the test had been made on the basis of the study of some 
8,000 species of plants, their characters, their spread, and their relations to those 
of other lands, Hooker concluded decisively in favour of mutability, and a 
doctrine of progression. After reading this essay, Darwin wrote that it was to 
his judgment ‘by far the grandest and most interesting essay on subjects of the 
nature discussed I have ever read.’ 
But beyond its historical interest in relation to the ‘Origin of Species,’ 
Hooker’s essay contained what was up to its time the most scientific treatment 
of a large area from the point of view of the Plant-Geographer. He found that 
the Antarctic, like the Arctic Flora, is very uniform round the Globe. The same 
species in many cases occur on every island, though thousands of miles of ocean 
may intervene. Many of these species reappear in the mountains of Southern 
Chili, Australia, Tasmania, and New Zealand. The Southern Temperate Floras, 
on the other hand, of South America, South Africa, Australia, and New Zea- 
land differ more among themselves than do the Floras of Europe, Northern 
Asia, and North America. To explain these facts Hooker suggested the probable 
former existence, during a warmer period than the present, of a centre of 
creation of new species in the Southern Ocean, in the form of either a con- 
tinent or an archipelago, from which the Antarctic Flora radiated. From the 
zoological side a similar difficulty arises, and the hypothesis of a land-connec- 
tion has been widely upheld, and that it existed as late as Mid-Tertiary 
times. The theory took a more definite form in the hands of Osborn (1900), 
who pictured relatively narrow strips of land connecting respectively South 
America on the one side and Tasmania and New Zealand on the other with 
the existing Antarctic land-area. This would accord well enough with the 
suggestion of Lowthian Green, that the plan of land-elevations on the Harth is 
approximately tetrahedral; and it is, I believe, in line with the views of those 
who are best informed on Antarctic Geography and Geology, as studied from 
the land itself. It may be hoped that further Antarctic discovery may bring 
fresh facts to bear upon this question, for it is to the positive data acquired from 
