LIFE OF THE LAND 



251 



light that the eyes of the animals are used. There are 

 no plants here and the life is much less abundant and less 

 varied than near the surface. 



There is but little variation in the conditions surround- 

 ing the animals of the sea, so the organs corresponding 

 to these conditions are not diverse. Living in a buoyant 

 medium dense enough to support their bodies, and of 

 almost unvarying tem- 

 perature, the sea ani- 

 mals have never re- 

 quired or developed 

 varied organs for loco- 

 motion, like the wing, 

 the hoof and the paw, 

 or for protection from 

 cold, like the feather, 

 the hair, or wool. It 

 is true that certain sea 

 dwellers, like the seal, 

 are covered with hair, 

 but these air breathers were probably originally a land type 

 and have acquired the habit of living in the water. The 

 highest traits of animal life, such as are found in land 

 animals, have not been required or acquired by the sea 

 animals, and although the number of species and kinds is 

 very great, there is not found among them the same grade 

 of intelligence or power of adaptability, as among the 

 land animals. 



116. Life of the Land. The highest development of both 

 plant and animal life is found upon the land. Here at 

 the meeting place of the solid earth and its gaseous en- 

 velope, subjected to great variations in amount of sun- 

 light, moisture, temperature and soil, the plants and 

 animals have acquired a marvelous variety of forms and 



SEALS. 

 Originally land animals. 



