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



Horn, but keeps some distance to the south of the Cape of 

 Good Hope. Tristan d'Acunha and Kerguelen Land stand 

 upon submarine plateaux which extend nearly to lat. 30° S., 

 but it is uncertain whether either of them is connected with 

 the antarctic plateau which surrounds the pole. The New- 

 Zealand plateau is said by Mr. Wallace to be connected with 

 the antarctic plateau ; but other geographers make a deep 

 channel between Campbell Island and Macquarie Island, and 

 another south of Macquarie Island. From what is known of 

 the geology of the antarctic islands it appears that all are 

 volcanic, except South Georgia, which is part of an old slate- 

 mountain range, and Kerguelen Land. 



If we examine the faunas and floras of the islands along 

 this track we find that Tristan d'Acunha, although three 

 times as far from Fuegia as it is from the Cape of Good Hope, 

 has its flora much more nearly allied to that of Fuegia than 

 to that of Africa. Kerguelen Land also has its flora much 

 more related to that of Fuegia than to that of the Auckland 

 Islands, although the distance is half as far again. This 

 island has also fifty-eight species of mai-ine mollusca, of which 

 thirteen are found in South America, six or seven in New 

 Zealand, and only four at the Cape of Good Hope ; and it 

 has one endemic land-shell — Helix Hookeri. Its fauna and 

 flora must therefore have come from the west and passed on 

 by the east to New Zealand. We have already seen, in the 

 early part of this address, that more land communication than 

 at present exists is necessary to explain the migration of the 

 antarctic fauna and flora ; and we have therefore in the ant- 

 arctic plateau, stretching from near South America in an 

 easterly direction to Victoria Land, and either connected with, 

 or but slightly separated from, land that extended to 30° S. 

 in the South Atlantic and Indian Oceans, the probable posi- 

 tion of the continent along which the migration took place, 

 but which was always separated from New Zealand by a 

 broad and deep channel south of Macquarie Island. 



There remains now only the question, What was the date 

 of this migration into New Zealand ? It is evident that it 

 could not have taken place, as a whole, in the Pliocene or 

 later, because we have already seen that the floras of the out- 

 lying islands have only differentiated some 20 per cent, in 

 species since the Pliocene ; while the New-Zealand antarctic 

 flora, as I mentioned in my last address, has differentiated by 

 about 65 per cent, in the species. Also it must, as a whole, 

 have been before the Eocene, as since then the differentiation 

 of species has been at least 90 per cent. The main immigra- 

 tion must therefore have taken place either in the Miocene, 



