168 TERRESTRIAL ANNELIDS. [CH. Ill 



necessarily fatal to the evidence offered by the un- 

 doubtedly struthious Argentine birds. 



As with the Sea-lions, also practically confined to the 

 southern hemisphere, the explanation of the range of 

 the Penguins is possibly rather one of temperature. The 

 Sea-lions are strong swimmers, and have been met with 

 far from land ; indeed the " Sea-serpent " is possibly partly 

 compounded of a large sea-lion. Currents too would assist 

 in the dispersal of these animals without any recourse to 

 a continuous coast-line to aid in migration. M. Milne 

 Edwards, whose name is particularly to be associated with 

 the idea of an antarctic region, has pointed out that 

 marine currents flow from the polar region in all direc- 

 tions northward ; with the aid of these currents, reinforced 

 by floating ice, which is known to reach land abutting 

 upon the southern ocean, we can understand the peopling 

 of Kerguelen and other regions with the birds and 

 mammals referred to. Mr Wallace while naturally ad- 

 mitting the resemblances between various tracts of land 

 in the southern hemisphere is disposed to rely upon float- 

 ing masses of ice to account for the facts. It is difficult 

 to apply this solution of a puzzling problem to the case 

 of the terrestrial Annelida of the antarctic area. It is a 

 curious fact that Mr Forbes with the material before him 

 did not use the strongest argument that could be used 

 in favour of his views ; since those papers were written 

 the evidence has moreover increased. The earthworm 

 fauna of New Zealand is perhaps as well known as is that 

 of any extra-European region. That our knowledge is 

 approaching completion is shown by the fact that collec- 



