104 Capt. F. W. Hutton on the Origin of the 



in their new home. Alpine plants might succeed if they were 

 blown into higher latitudes, but they would have less chance 

 than lowland plants in a migration towards the equator. So 

 that in the case of a migration between New Zealand and an 

 antarctic continent, alpine plants of the former would more 

 readily pass to the latter than the antarctic plants to New 

 Zealand. 



From these considerations it appears evident that antarctic 

 plants would have but a slight chance of establishing them- 

 selves in New Zealand if it were of smaller dimensions than 

 at present, and especially if the surrounding seas were warmer, 

 as appears to have been the case in the Oligocene and Mio- 

 cene periods. These plants must therefore have come either 

 during cold periods, of which there is no evidence, or else 

 they must have come during those periods of elevation in 

 which New Zealand stretched more to the south. This last 

 supposition is certainly the more reasonable, and it agrees 

 well with the proportion of endemic species found in the ant- 

 arctic and north-temperate elements. There must therefore 

 have been a greater continuity of land between Fuegia, Ker- 

 guelen Land, and New Zealand in both the Eocene and the 

 Pliocene than there is now. Whether this land was always 

 a series of islands, as it must have been in its earlier and its 

 later stages, or whether it once was nearly continuous, is 

 a matter of speculation. Of the twenty-one species of 

 flowering plants of Kerguelen Land, three (or 14 per cent.) 

 are found there only ; while eleven (or 50 per cent.) are con- 

 fined to Kerguelen, the Crozets, Marion Island, and Heard 

 Island. I should therefore judge, from what we know of the 

 flora of New Zealand, that this group of islands separated 

 from Fuegia in the Miocene, and that the islands themselves 

 were not separated from each other until late in the Pliocene. 

 The distribution of the petrels also points to the ancient date of 

 the present oceanic conditions of the southern hemisphere. 

 It is the only group of birds which has originated in the south 

 and spread to the north. The albatross, fulmar, and shear- 

 water of the north are all representatives of southern species, 

 while the south has several genera not represented at all in 

 the north — e. g. Ossifraga, Pterodroma, Duption, Prion, Pele- 

 canoides. The only genus better developed in the north than 

 in the south is that of the shearwaters (Puffinas), which is 

 hardly ever seen out of sight of land. All the truly oceanic 

 petrels are of southern origin*. From this it seems probable 

 that an antarctic continent south of Africa, and including 

 Tristan d'Acunha and Kerguelen Land, may have existed 

 * Hutton, 'Ibis,' 1865. 



