192 FIRST FORMS OF VEGETATION. 
quence been obtained into their functions and 
habits, which would otherwise either remain in ob- 
scurity, or be revealed only by the chance fortune 
of the hour. It would be interesting to state some 
of the novel facts thus elicited. But this would be 
irrelevant, as our attention in this chapter is to be 
occupied not with the history of the alge or sea- 
weeds as a whole, but only with that distinct and 
well-marked section of the family which inhabits 
fresh water exclusively, whose economy is alto- 
gether peculiar, and whose forms are widely dif- 
ferent from the lovely Plocamiums and Deles- 
serias, which we frequently observe with admira- 
tion in our wanderings along the sea-shore. 
There is a peculiar charm about fresh-water 
algz, derived from the nature of the element in 
which they live. Aquatic plants of all kinds are 
more interesting than land plants. Water is so 
bright, so pure, so transparent, so fit an emblem 
of that spiritual element in which our souls should 
bathe and be strengthened, from which they should 
drink and be satisfied. It is a perpetual baptism 
of refreshment to the mind and senses. It ideal- 
izes every object in it and around it; the com- 
monest and most vulgar scenes, reflected in its 
clear mirror, are pictorial and romantic. It is ever 
varying in its unity, so that the eye never wearies 
of gazing upon it. All these associations invest 
