74 THE OCEAN WOELD. 



of them, however," says Mr. Gosse, " if viewed with a lens under 

 water while in a living state, display vigorous currents constantly 

 pouring forth from certain orifices ; and we necessarily infer that the 

 water thus ejected must he constantly taken in through some other 

 channel. On tearing the mass open, we see that the whole substance 

 is perforated in all directions hy irregular canals, leading into each 

 other, of which some are slender, and communicate with the surface 

 hy minute hut numerous pores, and others are wide, and open hy 

 ample orifices ; through the former the water is admitted, through 

 the latter it is ejected." It is not to be denied, however, that these 

 beings constitute, in spite of investigations of modern naturalists, a 

 group still somewhat problematical, and still very imperfectly known 

 as regards their internal organization. 



Sponges are masses of a light elastic tissue, which is, at the same 

 time, resistant, full of air-cells, and with much varied exterior arrange- 

 ments. Nearly three hundred species are known, the different 

 appearances of which have been characterised by names more or less 

 singular. There is, for instance, the Feather Sponge, the Fan 

 Sponge, the Bell, the Lyre, the Trumpet, the Distaff, the Peacock 

 Tail, and Neptune's Grlove. 



There are river sponges and sea sponges. 



The first are irregular and arenaceous masses, which pile them- 

 selves upon plants and solid bodies immerged in fresh water. Such 

 are the spongilles, upon which anatomic and embryonic observations 

 have very frequently been made in relation to the group more im- 

 mediately under consideration. 



The second is found in almost every sea ; especially are they found 

 in the Mediterranean, the Eed Sea, and the Mexican Gulf. Affecting 

 warm and quiet waters, they attach themselves to bold and rugged 

 rocks at depths ranging from five to twenty-five fathoms. They are 

 erect, pendent, or spreading, according to their form or position. 

 Fig. 10, drawn from Nature, represents a very remarkable form of 

 sponge, which was fished up in sixty fathoms. 



The sponge is very common in the Mediterranean and round the 

 Grecian Archipelago, and is known vulgarly under the name of the 

 Marine Mushroom, the Sailor's Nest, and the fine soft sponge of 

 Syria. It is a mass more or less rounded, covered with a mucous bed, 

 glutinous above, formed of a light elastic but resisting tissue full of 



