THE BRITISH SPONGES. 



Every one may be presumed to be familiar with the ge- 

 neral appearance and structure of Sponge. It is a light 

 elastic porous substance formed of interlaced horny fibres, 

 producing, by their numerous inosculations, a rude sort of 

 net-work with meshes or j)ores of unequal sizes and usually 

 of a square or roundish angulated figure. Besides these 

 pores there are some circular holes of a larger size (osculd) 

 scattered over the surface of most sponges, and which lead 

 into sinuous canals that permeate their interior in every 

 direction. The oscula, canals and pores communicate free- 

 ly together, for the structm-e of the sponge is alike through- 

 out the mass, or at most the texture of the surface is mere- 

 ly a little more compact than the inner parts. The charac- 

 teristic property of sponge is the facility with which it im- 

 bibes a large quantity of any fluid, more especially of water, 

 which is retained amid the meshes until forced out again by 

 a sufficient degree of compression, when the specimen re- 



