30 THE POPULAR SCIENCE MONTHLY. 



" There is probably no latitude, between that of Spitzbergen and Victoria 

 Land, where some of the species of either country do not exist : Iceland, Brit- 

 ain, the Mediterranean Sea, North and South America, and the South-Sea 

 Islands, all possess antarctic Diatomacem. The silicious coats of species only 

 known living in the waters of tlie South Polar Ocean, have, during past ages, 

 contributed to the formation of rocks ; and thus they outlive several successive 

 creations of organized beings. The phronolite stones of the Ehine, and the Tri- 

 poli stone, contain species identical with what are now contributing to form a 

 sedimentary deposit (and, perhaps, at some future period, a bed of rock) extend- 

 ing in one continuous stratum for 400 measured miles. I allude to the shores 

 of the Victoria Barrier, along whose coast the soundings examined were inva- 

 riably charged with diatomaceous remains, constituting a bank which stretches 

 200 miles north from the base of Victoria Barrier, while the average depth of 

 water above it is 300 fatlioms, or 1,800 feet. Again, some of the antarctic spe- 

 cies have been detected floating in the atmosphere which overhangs the wide 

 ocean between Africa and America. The knowledge of this marvelous fact we 

 owe to Mr. Darwin, who, when he was at sea off the Cape de Verd Islands, col- 

 lected an impalpable powder which fell on Captain Fitzroy's ship. He trans- 

 miflled this dust to Ehrenberg, who ascertained it to consist of the silicious 

 coats, chiefly of American Biatomacece, which were being wafted through the 

 upper region of the air, when some meteorological phenomena checked them in 

 their course and deposited them on the ship and surface of the ocean. 



" The existence of the remains of many species of this order (and among 

 them some antarctic ones) in the volcanic ashes, pumice, and scorias 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 Ere- 

 bus, 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 lati- 

 tude, and abreast of the Diatomacem 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 sub- 

 terranean and subaqueous forces which maintain Mount Erebus in activity may 

 occasionally receive organic matter from the bank, and disgorge it, together 

 with those 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 Diatomacem. 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 Diatomacem. 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 remains." 



The Challenger has explored the antarctic seas in a region inter- 

 mediate between those examined by Sir James Ross's expedition; 

 and the observations made by Dr. Wyville Thomson and his col- 

 leagues in every respect confirm those of Dr. Hooker : 



" On the 11th of February, latitude C0 52' south, longitude 80 20' east, and 

 March 3d, latitude 53 55' south, longitude 108 35' east, the sounding instru- 

 caent came up filled with a very fine cream-colored paste, which scarcely efier- 



