52 THE OCEAN. 



thrown out some new shoots, and several additional 

 articulations. Eight weeks have now elapsed since 

 the experiment was begun, — the water has remained 

 unchanged, — yet the Coralline is growing, and appa- 

 rently has lost none of its vitality ; but the animals 

 have sensibly decreased in number, though many of 

 them continue to be active, and show no dislike to 

 their situation. What can be more conclusive ? I 

 need not say that if any animal, or even a sponge, 

 had been so confined, the water would long before 

 this time have been deprived of its oxygen, would 

 have become corrupt and ammoniacal, and poisonous 

 to the life of every living thing." * 



Who is not familiar with Sponge, — with its soft- 

 ness, its elasticity, its capacity of absorbing and re- 

 taining fluids, and other qualities which render it so 

 valuable in domestic economy ? And yet how few 

 are aware that it is the skeleton of an animal ! In 

 fact, Sponge is one of those dubious forms which God 

 has placed in the great system of Creation, on the 

 confines of the two great divisions of organic beings, 

 apparently having little in common with either. 

 Like the Corallines, the Sponges have afibrded occa- 

 sion for much controversy as to their proper position ; 

 but they are now pretty unanimously assigned to the 

 animal kingdom. The common Sponge of household 

 purposes [Spongia officinalis) is a native of the Medi- 

 terranean, but is much more familiar to us than our 

 native species, of which there are many. The ap- 

 pearance which it presents is that of an irregularly- 

 shaped mass, more or less rounded, composed of a 



* British Sponges, p. 215. 



