7O THE WORLD OF THE SEA. 
waters, and places not exposed to the action of waves and currents. 
Their colonies live at the bottom of the seas, in five to twenty-five 
SPONGE UPON A SEA-WEED. 
(Fished up from a depth of sixty fathoms.) 
fathoms of water, among the clefts and crevices of the rocks, to 
which they are always attached. They are, however, found not 
only on inorganic bodies, but also on vegetables and animals. 
