REPORT ON THE BOTANY OF THE ISLANDS OF THE SOUTHERN OCEAN. 191 



the sea surface, and forms the common foundation of all the islands situated in this part of the world, 

 viz., Prince Edward's Islands, the Crozet Islands, the Kerguelen Group, the Heard Islands, and the 

 islands of St Paul and Amsterdam,' ' as proved by the soundings of both the " Challenger " and the 

 " Gazelle." ' The occurrence with the cabbage on Heard Island of the helpless wingless fly, 1 seems a 

 further proof that the plant was not conveyed to the various islands by birds. It is hardly possible 

 that both could have been transported, and the fly could probably not exist without the cabbage. 

 The existence of the same species of freshwater fish in New Zealand, Tasmania, the Falkland 

 Islands, and South America, points also to the former existence of more intervening land between 

 these points." 



To the foregoing we have nothing to add beyond the remarks under each species in 

 the ensuing list. 



1 Cali/copteryx moseleyi, Eaton, Verrall in Phil. Trans. Roy. Soc. Lond., clxviii. p. 239, t. 14, fig. 1 a-e. 



