258 FIRST FORMS OF VEGETATION. 
enormous bank, flanking at an average depth of 
1800 feet the whole length of Victoria Barrier—a 
glacier of ice some 400 miles long and 120 broad. 
And it is extremely probable that they are 
uniformly dispersed over the whole surface of the 
ocean; for, owing to their extreme minuteness 
in their individual state, and the transparency of 
their tissues, they cannot be perceived by the 
naked eye unless when accumulated into immense 
masses and contrasted with opaque substances. 
The surface of the sea, it has been said, is one 
wide nursery, its every ripple a cradle, and its 
bottom one vast cemetery. The floor of the 
ocean is paved with these organisms; those 
mysterious submarine plains, where the seer’s 
vision of the ‘sea of glass’ seems realized, where 
no wind blows, and no storm rages, and no 
current frets, are covered with their remains 
unmixed even with a single particle of sand. 
The soundings obtained from these silent motion- 
less depths, are as pure and free from the slightest 
intermixture of other matter, as the new-fallen 
snow-flake is from the dust of the earth. And as 
a snow-cloud in a still January evening discharges 
its wavering flakes upon the earth, so are the 
waves continually letting fall upon their bed 
showers of minute diatoms whose term of life had 
expired, kindly strewing the melancholy wrecks 
