- 26 — 



Australia, and many alternatives have been offered to explain 

 the former land connection between the localities, which 

 undoubtedly once existed. 



If Tasmania and Australia, and New Zealand, and southern 

 South America were connected with the antarctic continent at 

 the same time, it is probable that at that time the portion of 

 the antarctic littoral between them enjoyed a very mild climate, 

 even though it did not extend further toward the north than it 

 does today; for the antarctic stream would have been inter- 

 rupted, resulting in the sinking of the abyssal water in the south 

 Pacific to a very much lower level than it now reaches, and the 

 south equatorial currents of the Pacific, immensely increased 

 in size and power and more nearly comparable to the Kuro- 

 Siwo or the Gulf Stream, would have been able to extend 

 themselves over the cold abyssal water like a blanket, per- 

 mitting, through their effect upon the shore climate, the existence 

 in the antarctic littoral of many, if not most, of the types which 

 we now know as common to South America, New Zealand, and 

 Tasmania and Australia. 



SUMMARY. 



The water of the antarctic regions is entirely abyssal water, 

 derived from the abysses of the Pacific, Atlantic and Indian 

 Oceans. The circumpolar antarctic currents, and the currents 

 originating in the antarctic and flowing thence northward (the 

 Humbolt, Benguela and Australian currents) belong to the 

 abyssal circulation of the oceans, and are in no way related to 

 the surface currents of more northern latitudes. 



Antarctic water enters the basins of the Pacific, Atlantic 

 and Indian oceans as great peripheral currents flowing along 

 the southern, southeastern and eastern borders, which plunge 

 beneath the surface at about the latitude of the equator, but 

 are continued as deep currents northward and then westward 

 and again southward along the eastern margins of these basins. 



