228 THE OCEAN 



cool, dry, and heavy air descending in anti- 

 cyclonic areas. The gases of the atmosphere 

 penetrate the soil and rocky crust, and are 

 absorbed at the surface of the ocean, being 

 carried to the greatest depths by the circula- 

 tion of ocean waters. 



The hydrosphere has been specially con- 

 sidered in the preceding chapters. It is 

 mostly made up of the waters of the ocean, 

 and lakes and rivers are also included. Some 

 of the water may be in the solid and gaseous 

 states, as ice, snow, hail and the water- 

 vapour of the atmosphere. Water likewise 

 penetrates deeply into the rocky crust, where 

 it produces the hydration of minerals, and 

 water forms a large part of the biosphere. 



The biosphere : Wherever water is present, 

 or rather wherever water, air, and earth are 

 in contact and commingle, life in some of its 

 many forms can usually be detected. Indeed 

 the whole planet may be regarded as clothed 

 with a mantle of living matter. If we choose 

 to give our imagination a little more rein, 

 then we may say that within the biosphere 

 a sphere of reason and intelligence has been 

 evolved in man, who attempts to interpret 

 and explain the cosmos ; this may be called 

 the psychosphere. 



The lithosphere consists of the hard rocky 

 crust with which we are familiar on the con- 



