78 EXPEDITION OF THE " CHALLENGER " m 



(and amongst them some Antarctic ones) in the volcanic ashes, 

 pumice, and scoriae of active and extinct volcanoes (those of the 

 Mediterranean Sea and Ascension Island, for instance) is a fact 

 bearing immediately upon the present subject. Mount Erebus, 

 a volcano 12,400 feet high, of the first class in dimensions and 

 energetic action, rises at once from the ocean in the seventy- 

 eighth degree of south latitude, and abreast of the Diatomacece 

 bank, which reposes in part on its base. Hence it may not 

 appear preposterous to conclude that, as Vesuvius receives the 

 waters of the Mediterranean, with its fish, to eject them by its 

 crater, so the subterranean and subaqueous forces which maintain 

 Mount Erebus in activity may occasionally receive organic 

 matter from the bank, and disgorge it, together with tho.se 

 volcanic products, ashes and pumice. 



"Along the shores of Graham's Land and the South Shetland 

 Islands, we have a parallel combination of igneous and aqueous 

 action, accompanied with an equally copious supply of Diatom- 

 accce. In the Gulf of Erebus and Terror, fifteen degrees north 

 of Victoria Land, and placed on the opposite side of the globe, 

 the soundings were of a similar nature with those of the Victoria 

 Land and Barrier, and the sea and ice as full of Diatomacece, 

 This was not only proved by the deep sea lead, but by the 

 examination of bergs which, once stranded, had floated off and 

 become reversed, exposing an accumulation of white friable mud 

 frozen to their bases, which abounded with these vegetable 



The Challenger has explored the Antarctic seas 

 in a region intermediate between those examined 

 by Sir James Eoss's expedition; and the observa- 

 tions made by Dr. Wyville Thomson and his 

 colleagues in every respect confirm those of Dr. 

 Hooker : 



"On the llth of February, lat. 60 52' S., long. 80 20' E., 

 and March 3, lat. 53 55' S., long. 108 35' E., the sounding 



