ANIMAL DEBRIS IN THE SEA. 55 



4. Solid Bodies in the Sea — Phosphorescence. 



The sea holds in suspension a great variety of 

 solid matters. In the first rank are fish, which 

 float in the liquid element as birds in the air, 

 whilst the other living creatures of the ocean are 

 under the necessity of finding a point of support on 

 the submarine soil. The number of creatures float- 

 ing in the water is enormous. Many species of 

 them congregate in shoals, which have sometimes 

 been known to cover hundreds of square leagues of 

 surface, and extend several hundreds of feet in 

 thickness or depth. It is not, however, to the 

 natural history of animals that our attention is now 

 Ccdled. Our subject is the sea-bottom, and it is only 

 80 far as any creature lives on the submarine soil, or 

 leaves its spoils there, that we owe it any special 

 regard. One passing observation may be made. It 

 seems certain that such immense shoals of living 

 beings must vitiate the aqueous atmosphere in which 

 they float, just as any other similar congregation of 

 men or animals would affect the surface of the earth 

 and the air they breathe. Their debris must un- 

 doubtedly be reckoned among the agents by which 

 the basin of the sea is more or less modified. 



The spawn of fish existing in such numbers forms 

 enormous banks, and it is to this cause that the 



