534 LIFE AS RELATED TO PHYSICAL CONDITIONS 



FLYING FISH 



Notice how the front fins have become 

 wing-like 



this phosphorescent 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 con- 

 ditions surrounding 

 the animals of the 

 sea, and so the organs 

 corresponding to 

 these conditions are 

 not diverse. Living 

 in a buoyant medium 

 dense enough to sup- 

 port their bodies, and of almost unvarying temperature, the 

 sea animals have never required or developed varied organs 

 for locomotion, 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 prob- 

 ably originally a land 

 type and have ac- 

 quired the habit of SEALS 



living in the Water. Originally land animals. 



