56 THE NOTOG;EIC REALM. [CHAP. 



possibly in a zone nearer the equator 1 . Assuming such a connec- 

 tion to have existed in Tertiary times (and there is no reason why 

 it should not have existed), it must either have taken place 

 before the development of the diprotodonts in Australia, or must 

 have been in such high latitudes, or so transitory, as to permit of 

 the passage of only a few forms. It is true that there is no 

 definite evidence that land mammals ever existed on the Antarctic 

 continent, but during a recent expedition certain seals were killed 

 bearing on their hides marks which appeared to have been inflicted 

 by the claws of a land carnivore. If this be substantiated by 

 future discoveries, it would be not only probable, but essential 

 that there should have been a Tertiary connection between 

 'Antarctica' and other lands. With regard to the probability that 

 'Antarctica' is of continental origin, in summarising what is known 

 with regard to the geology of 'Antarctica,' Messrs David and 

 Smeeth observe that whether a continent, or an archipelago the 

 islands of which are united by thick sheets of ice, the southern land 

 is considered to have a superficial area of 4,000,000 square miles, 

 being, therefore, larger than Australia. A great chain of volcanoes 

 has been described, which in Victorialand rise over 15,000 ft. 

 above the sea. On the South American side of Antarctica may 

 be specially noticed the active volcano of Bridgman, and the 

 large and partially-submerged volcano of Deception Island, with 

 its crater over five miles in diameter, the wall of which, built up of 

 alternating layers of ice and volcanic scoriae, rises to 1,800 ft. 

 above the sea. Sedimentary rocks of Eocene age, with fossil trees, 

 were discovered in 1893 at Seymour Island; and the French ship 

 Talisman many years previously dredged off the Antarctic conti- 

 nent fragments of rock containing Gyroporella, a fossil plant very 

 characteristic of the Triassic rocks of Europe. Near Laurie Island, 

 in the South Orkneys, limestone occurs. The rocks collected by 

 Mr Borchgrevink are of especial interest as confirming the theory 

 that Antarctica is a continent rather than an archipelago, for the 

 microline-granite with garnet and tourmaline, and the mica-schists 

 must have had a continental origin, such rocks being almost 

 unknown in oceanic islands, but being of frequent occurrence in 

 continental areas. 



1 See Chapter III. 



