THE RENEWAL OF ANTARCTIC EXPLORATION. 367 



desirable at different seasons of tlie year, with iniprove<l tlierniometers 

 and other instiunients. Here, again, a new Antarctic ''\ ^edition Mould 

 supply the knowledge essential to a correct solution of many problems 

 in Oceanography. Ross describes a strong tidal curient and rip between 

 Possession Island and tlie mainland of Victoria, but on the whole, we 

 have very little inforuuition concerning the tides and surface currents 

 in the Antarctic. 



No laud animal, and uo trace of vegetation, not even a lichen or a 

 piece of seaweed, has been found on land within the Antarctic circle. 

 On Cockburn Island, in latitude 04^ south, Hooker collected twenty 

 cryptogamic species, three of them seaweeds, and this may be regarded 

 as not far from the southern limit of terrestrial vegetation. The fossils 

 and fossiliferous beds above referred to distinctly indicate the existence 

 of more genial conditions within the Antarctic m past geological times, 

 and should be fully explored. 



When we turn to the waters of the Antarctic Ocean, we find at the 

 present time a great profusion of life, both animal and vegetable. Dur- 

 ing the ChaUcufjcr expedition, myriads of minute spherical tetrasporiie 

 were observed to give the sea a peculi.ir green color over large areas. 

 Diatoms were frequently in such enormous abundance, that the tow nets 

 were filled to the brim with a yellow-brown slimy mass, with a distress- 

 ing odor, through which various crustaceans, annelids, and other animals 

 wriggled. 



As these marine algte are the primary source of food in the sea, their 

 great develoi)ment in the Antarctic Ocean leads to a corresponding 

 abundance of animals. Occasionally vast quantities of Co])ei)ods 

 Amphipods, and Schizopods were observed to give the ocean a dull 

 red color, and the more delicate tow nets were at such times so filled 

 with these animals, that they occasionally burst on being hauled on 

 board ship. These small crustaceans are in turn the chief food of the 

 fishes, penguins, seals, and whales, Avhich abound in the waters of the 

 Great Southern Ocean. 



Organisms such as the diatoms and radiolaria, which secrete silica, 

 and the foramiuifera and pteropods, which secrete carbonate of lime, 

 are, on account of their distribution, the most interesting of all the 

 pelagic creatures captured in the surface and sub-surface waters of the 

 ocean. Near Antarctic land the deposits at the bottom of the sea are, 

 as already stated, mostly made up of rock fragments and detritus from 

 the snow-clad Antarctic continent. A little to the north the number 

 of these particles decreases, and they are largely rei)laced by the dead 

 frustrules of diatoms and radiolaria, and then we find a pure white 

 siliceous deposit at the bottom, which is called a diatom ooze. Still 

 farther to the north, when the infiueuce of the warm northern currents 

 commences to be felt, the diatoms are largely replaced on the surface 

 by the calcareous shells of foramiuifera and pteropods, and at the 

 bottom of the sea in these latitudes the diatom ooze gives place to a 



