PROFUSION OF ANIMAL LIFE. 89 



itself becomes a nutritious fluid to many of the large inhab- 

 itants of the ocean. 



Even in the bleak and dreary regions of the Northern 

 world the wintry seas are filled with a profusion of animal 

 life. The smaller species, of which the herring may be 

 taken for an example, are found amidst the depths of the 

 Arctic zone in immense shoals ; countless millions of crea- 

 tures, sometimes known as sea nettles, a genus of Acalephce, 

 signifying "nettles" (so named from the stinging power 

 which many of them possess), of higher organization than 

 the Medusce, or jelly-fish, exist here, with globular or oval 

 bodies of a delicate or jelly-like substance, strengthened by 

 bands which are covered with rows of large cilia (a peculiar 

 sort of moving organs resembling microscopic hairs), the 

 motion of which is extremely rapid, and is evidently con- 

 trolled by the will of the little animal. Jelly-Fish, Zoophytes^ 

 etc., swarm also to such an extent as to convert the surface 

 water in some places almost into a kind of soup, which fur- 

 nishes food not only to small fish, but to whales and animals 

 of the largest growth. Even the color of the ocean is influ- 

 enced by the enormous quantity of the organic life it sus- 

 tains. The application of the microscope — for by far the 

 most numerous of the animalcules can only thus be traced — 

 shows them to be the cause of a peculiar tinge observed 

 over a great extent of the Greenland Sea. This color is 

 olive-green, and the water is dark and dense compared to 

 that which bears the common cerulean hue. The portion of 

 the ocean so distinguished amounts to not less than twenty 

 thousand square miles, and hence the number of animalculas 

 which that space contains is far beyond human calculation. 



Some of the calculations of an ingenious and clever writer 

 are very curious and instructive. In a drop of water there 

 were fifty of these animalculae, on an average, in each square 

 of the micrometer-glass of an eight hundred and fortieth of 

 an inch ; and as the drop occupied a circle on a plate of 



