THE VASCULAR FLORA OF MACQUARIE ISLAND.—CHEESEMAN. 
45 
element in the flora would much surpass any other. But if the distribution of the 
thirty-one non-endemic plants of Macquarie Island be further examined, the remarkable 
fact appears that fifteen, or practically one-half, are also found in Fuegia or the South 
Georgia to Kerguelen groups of islands. In other words, they inhabit a ring or zone 
of widely separated lands surrounding the Antarctic Continent within the parallels 
45° S. to 60° S. I give a list of these “ circumpolar” species, as they are now often 
termed. 
Plants with a more or less circumpolar 
Ranunculus biternatus Smith. 
Cardamine corymb os a Hook. f. 
Montia fontana Linn. 
Accena adscendens Vahl. 
Tillcea moschata D.C. 
Callitriche antarctica Engelm. 
Azorella Selago Hook. f. 
Cotula plumosa Hook. f. 
distribution found in Macquarie Island :— 
Juncus scheuchzerioides Gaud. 
Car ex trifida Cav. 
Agrostis magellanica Lam. 
Festucci erect a D’Urv. 
Lomaria penna-marina Trev. 
Aspidium vestitum Swartz. 
Polypodium australe Mett. 
The presence of these “ circumpolar” species on Macquarie Island would alone 
demand some explanation; but when we learn that they form as large a proportion of 
the non-endemic vegetation of Kerguelen and South Georgia as they do of Macquarie 
' Island, notwithstanding the immense distance between the three localities, then it 
becomes evident that no inquiry into the origin and history of the Macquarie florula 
can be successfully carried out without dealing with the whole of the Subantarctic zone 
surrounding the Antarctic Continent, and that continent itself. In my memoir on 
the Subantarctic Islands of New Zealand, previously alluded to, I have treated at 
some length of this branch of the subject. I will therefore refer the reader to that 
publication for many minor details which it is unnecessary to mention here, confining 
myself to the elucidation of the proper subject of this memoir, and to the presentment 
of those facts, old and new, that are necessary to support the views advanced. 
If first of all we take the Antarctic Continent, at present almost entirely covered 
with an everlasting mantle of snow and ice, we find that two Fuegian plants, Coloban- 
thus crassijolius and Deschampsia antarctica, constitute the whole of the vascular 
vegetation. Neither of these is known from Macquarie Island, but as two species 
of both genera occur thereon, a certain amount of affinity is evident. 
But although the living flora of Antarctica has been reduced to such small 
dimensions as to be of little use in tracing the origin and connections of the subantarctic 
flora, it is quite different with respect to the fossil flora. In Graham Land and the 
adjacent islands, which collectively make the nearest approach to South America, 
