ANTAECTIC VEGETATION. 483 



This vegetation forms undoubtedly the food 

 of many of the countless marine tribes peopling 

 the antarctic waters, and which are subsequently 

 themselves a prey to larger creatures. They 

 were invariably found in the stomachs of sea 

 animals, in all latitudes between that of the 

 north tropic and the highest parallel attained 

 by the antarctic expedition. The death and 

 decomposition of this antarctic vegetation are 

 gradually producing a submarine deposit or 

 bank of vast dimensions. This bank consists 

 mainly of the silicious coatings of the cells, 

 intermixed with infusoria and inorganic matter. 

 Its position is from the 76th to the 78th degree 

 of south latitude, and between the meridians of 

 165 east and 160 west longitude ; thus occupy- 

 ing an area of 400 miles long by 120 wide. 

 All the soundings taken over this deposit brought 

 up the finest green mud, mixed with sand 

 occasionally, from the depth of between 200 and 

 400 fathoms. The lead sometimes sank two feet 

 into this pasty deposit. 



Let us now inquire how is the marine vege- 

 tation nourished, and what are the chemical 

 functions it discharges ? If we were to subject 

 sea-weed to chemical analysis, we should find 

 that it contained a large amount of carbon, a 

 certain portion of oxygen and hydrogen, and a 

 little nitrogen. But there would be more than 

 this; we should find also some earthy, some 



